add #[hdl(cmp_eq)] to implement HdlPartialEq automatically

As some proofs involving memories, it is necessary to add more ports to
the queue interface, to sync state. These changes are predicated on the
test environment, so normal use is not affected.

Since some speedup is achieved, use the saved time to test with a deeper
FIFO.

.forgejo/workflows/test.yml

@@ -38,7 +38,7 @@ jobs:
             z3 \
             zlib1g-dev
       - run: |
-          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain 1.80.1
+          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain 1.82.0
           source "$HOME/.cargo/env"
           echo "$PATH" >> "$GITHUB_PATH"
       - uses: https://code.forgejo.org/actions/cache/restore@v3
@@ -57,4 +57,5 @@ jobs:
           save-if: ${{ github.ref == 'refs/heads/master' }}
       - run: cargo test
       - run: cargo build --tests --features=unstable-doc
+      - run: cargo test --doc --features=unstable-doc
       - run: cargo doc --features=unstable-doc

Cargo.lock

@@ -301,7 +301,7 @@ checksum = "25cbce373ec4653f1a01a31e8a5e5ec0c622dc27ff9c4e6606eefef5cbbed4a5"
 
 [[package]]
 name = "fayalite"
-version = "0.2.1"
+version = "0.3.0"
 dependencies = [
  "bitvec",
  "blake3",
@@ -315,23 +315,25 @@ dependencies = [
  "num-bigint",
  "num-traits",
  "os_pipe",
+ "petgraph",
  "serde",
  "serde_json",
  "tempfile",
  "trybuild",
+ "vec_map",
  "which",
 ]
 
 [[package]]
 name = "fayalite-proc-macros"
-version = "0.2.1"
+version = "0.3.0"
 dependencies = [
  "fayalite-proc-macros-impl",
 ]
 
 [[package]]
 name = "fayalite-proc-macros-impl"
-version = "0.2.1"
+version = "0.3.0"
 dependencies = [
  "base16ct",
  "num-bigint",
@@ -345,7 +347,7 @@ dependencies = [
 
 [[package]]
 name = "fayalite-visit-gen"
-version = "0.2.1"
+version = "0.3.0"
 dependencies = [
  "indexmap",
  "prettyplease",
@@ -357,6 +359,12 @@ dependencies = [
  "thiserror",
 ]
 
+[[package]]
+name = "fixedbitset"
+version = "0.5.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d674e81391d1e1ab681a28d99df07927c6d4aa5b027d7da16ba32d1d21ecd99"
+
 [[package]]
 name = "funty"
 version = "2.0.0"
@@ -423,9 +431,9 @@ checksum = "ce23b50ad8242c51a442f3ff322d56b02f08852c77e4c0b4d3fd684abc89c683"
 
 [[package]]
 name = "indexmap"
-version = "2.2.6"
+version = "2.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "168fb715dda47215e360912c096649d23d58bf392ac62f73919e831745e40f26"
+checksum = "68b900aa2f7301e21c36462b170ee99994de34dff39a4a6a528e80e7376d07e5"
 dependencies = [
  "equivalent",
  "hashbrown",
@@ -472,11 +480,10 @@ checksum = "01cda141df6706de531b6c46c3a33ecca755538219bd484262fa09410c13539c"
 
 [[package]]
 name = "num-bigint"
-version = "0.4.4"
+version = "0.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "608e7659b5c3d7cba262d894801b9ec9d00de989e8a82bd4bef91d08da45cdc0"
+checksum = "a5e44f723f1133c9deac646763579fdb3ac745e418f2a7af9cd0c431da1f20b9"
 dependencies = [
- "autocfg",
  "num-integer",
  "num-traits",
 ]
@@ -515,6 +522,15 @@ dependencies = [
  "windows-sys 0.59.0",
 ]
 
+[[package]]
+name = "petgraph"
+version = "0.6.5"
+source = "git+https://github.com/programmerjake/petgraph.git?rev=258ea8071209a924b73fe96f9f87a3b7b45cbc9f#258ea8071209a924b73fe96f9f87a3b7b45cbc9f"
+dependencies = [
+ "fixedbitset",
+ "indexmap",
+]
+
 [[package]]
 name = "prettyplease"
 version = "0.2.20"
@@ -527,9 +543,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.83"
+version = "1.0.92"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b33eb56c327dec362a9e55b3ad14f9d2f0904fb5a5b03b513ab5465399e9f43"
+checksum = "37d3544b3f2748c54e147655edb5025752e2303145b5aefb3c3ea2c78b973bb0"
 dependencies = [
  "unicode-ident",
 ]
@@ -631,9 +647,9 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
 [[package]]
 name = "syn"
-version = "2.0.66"
+version = "2.0.93"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c42f3f41a2de00b01c0aaad383c5a45241efc8b2d1eda5661812fda5f3cdcff5"
+checksum = "9c786062daee0d6db1132800e623df74274a0a87322d8e183338e01b3d98d058"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -720,6 +736,12 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
+[[package]]
+name = "vec_map"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1bddf1187be692e79c5ffeab891132dfb0f236ed36a43c7ed39f1165ee20191"
+
 [[package]]
 name = "version_check"
 version = "0.9.4"

Cargo.toml

@@ -5,18 +5,18 @@ resolver = "2"
 members = ["crates/*"]
 
 [workspace.package]
-version = "0.2.1"
+version = "0.3.0"
 license = "LGPL-3.0-or-later"
 edition = "2021"
 repository = "https://git.libre-chip.org/libre-chip/fayalite"
 keywords = ["hdl", "hardware", "semiconductors", "firrtl", "fpga"]
 categories = ["simulation", "development-tools", "compilers"]
-rust-version = "1.80.1"
+rust-version = "1.82.0"
 
 [workspace.dependencies]
-fayalite-proc-macros = { version = "=0.2.1", path = "crates/fayalite-proc-macros" }
+fayalite-proc-macros = { version = "=0.3.0", path = "crates/fayalite-proc-macros" }
-fayalite-proc-macros-impl = { version = "=0.2.1", path = "crates/fayalite-proc-macros-impl" }
+fayalite-proc-macros-impl = { version = "=0.3.0", path = "crates/fayalite-proc-macros-impl" }
-fayalite-visit-gen = { version = "=0.2.1", path = "crates/fayalite-visit-gen" }
+fayalite-visit-gen = { version = "=0.3.0", path = "crates/fayalite-visit-gen" }
 base16ct = "0.2.0"
 bitvec = { version = "1.0.1", features = ["serde"] }
 blake3 = { version = "1.5.4", features = ["serde"] }
@@ -24,19 +24,22 @@ clap = { version = "4.5.9", features = ["derive", "env", "string"] }
 ctor = "0.2.8"
 eyre = "0.6.12"
 hashbrown = "0.14.3"
-indexmap = { version = "2.2.6", features = ["serde"] }
+indexmap = { version = "2.5.0", features = ["serde"] }
 jobslot = "0.2.19"
-num-bigint = "0.4.4"
+num-bigint = "0.4.6"
 num-traits = "0.2.16"
 os_pipe = "1.2.1"
+# TODO: switch back to crates.io once petgraph accepts PR #684 and releases a new version
+petgraph = { git = "https://github.com/programmerjake/petgraph.git", rev = "258ea8071209a924b73fe96f9f87a3b7b45cbc9f" }
 prettyplease = "0.2.20"
 proc-macro2 = "1.0.83"
 quote = "1.0.36"
 serde = { version = "1.0.202", features = ["derive"] }
 serde_json = { version = "1.0.117", features = ["preserve_order"] }
 sha2 = "0.10.8"
-syn = { version = "2.0.66", features = ["full", "fold", "visit", "extra-traits"] }
+syn = { version = "2.0.93", features = ["full", "fold", "visit", "extra-traits"] }
 tempfile = "3.10.1"
 thiserror = "1.0.61"
 trybuild = "1.0"
+vec_map = "0.8.2"
 which = "6.0.1"

crates/fayalite-proc-macros-impl/src/hdl_bundle.rs

@@ -83,6 +83,7 @@ impl ParsedBundle {
             custom_bounds,
             no_static: _,
             no_runtime_generics: _,
+            cmp_eq: _,
         } = options.body;
         let mut fields = match fields {
             syn::Fields::Named(fields) => fields,
@@ -437,6 +438,7 @@ impl ToTokens for ParsedBundle {
             custom_bounds: _,
             no_static,
             no_runtime_generics,
+            cmp_eq,
         } = &options.body;
         let target = get_target(target, ident);
         let mut item_attrs = attrs.clone();
@@ -765,6 +767,69 @@ impl ToTokens for ParsedBundle {
             }
         }
         .to_tokens(tokens);
+        if let Some((cmp_eq,)) = cmp_eq {
+            let mut where_clause =
+                Generics::from(generics)
+                    .where_clause
+                    .unwrap_or_else(|| syn::WhereClause {
+                        where_token: Token![where](span),
+                        predicates: Punctuated::new(),
+                    });
+            let mut fields_cmp_eq = vec![];
+            let mut fields_cmp_ne = vec![];
+            for field in fields.named() {
+                let field_ident = field.ident();
+                let field_ty = field.ty();
+                where_clause
+                    .predicates
+                    .push(parse_quote_spanned! {cmp_eq.span=>
+                        #field_ty: ::fayalite::expr::ops::ExprPartialEq<#field_ty>
+                    });
+                fields_cmp_eq.push(quote_spanned! {span=>
+                    ::fayalite::expr::ops::ExprPartialEq::cmp_eq(__lhs.#field_ident, __rhs.#field_ident)
+                });
+                fields_cmp_ne.push(quote_spanned! {span=>
+                    ::fayalite::expr::ops::ExprPartialEq::cmp_ne(__lhs.#field_ident, __rhs.#field_ident)
+                });
+            }
+            let cmp_eq_body;
+            let cmp_ne_body;
+            if fields_len == 0 {
+                cmp_eq_body = quote_spanned! {span=>
+                    ::fayalite::expr::ToExpr::to_expr(&true)
+                };
+                cmp_ne_body = quote_spanned! {span=>
+                    ::fayalite::expr::ToExpr::to_expr(&false)
+                };
+            } else {
+                cmp_eq_body = quote_spanned! {span=>
+                    #(#fields_cmp_eq)&*
+                };
+                cmp_ne_body = quote_spanned! {span=>
+                    #(#fields_cmp_ne)|*
+                };
+            };
+            quote_spanned! {span=>
+                #[automatically_derived]
+                impl #impl_generics ::fayalite::expr::ops::ExprPartialEq<Self> for #target #type_generics
+                #where_clause
+                {
+                    fn cmp_eq(
+                        __lhs: ::fayalite::expr::Expr<Self>,
+                        __rhs: ::fayalite::expr::Expr<Self>,
+                    ) -> ::fayalite::expr::Expr<::fayalite::int::Bool> {
+                        #cmp_eq_body
+                    }
+                    fn cmp_ne(
+                        __lhs: ::fayalite::expr::Expr<Self>,
+                        __rhs: ::fayalite::expr::Expr<Self>,
+                    ) -> ::fayalite::expr::Expr<::fayalite::int::Bool> {
+                        #cmp_ne_body
+                    }
+                }
+            }
+            .to_tokens(tokens);
+        }
         if let (None, MaybeParsed::Parsed(generics)) = (no_static, &self.generics) {
             let static_generics = generics.clone().for_static_type();
             let (static_impl_generics, static_type_generics, static_where_clause) =

crates/fayalite-proc-macros-impl/src/hdl_enum.rs

@@ -155,7 +155,11 @@ impl ParsedEnum {
             custom_bounds,
             no_static: _,
             no_runtime_generics: _,
+            cmp_eq,
         } = options.body;
+        if let Some((cmp_eq,)) = cmp_eq {
+            errors.error(cmp_eq, "#[hdl(cmp_eq)] is not yet implemented for enums");
+        }
         attrs.retain(|attr| {
             if attr.path().is_ident("repr") {
                 errors.error(attr, "#[repr] is not supported on #[hdl] enums");
@@ -211,6 +215,7 @@ impl ToTokens for ParsedEnum {
             custom_bounds: _,
             no_static,
             no_runtime_generics,
+            cmp_eq: _, // TODO: implement cmp_eq for enums
         } = &options.body;
         let target = get_target(target, ident);
         let mut struct_attrs = attrs.clone();

crates/fayalite-proc-macros-impl/src/hdl_type_alias.rs

@@ -49,10 +49,14 @@ impl ParsedTypeAlias {
             custom_bounds,
             no_static,
             no_runtime_generics: _,
+            cmp_eq,
         } = options.body;
         if let Some((no_static,)) = no_static {
             errors.error(no_static, "no_static is not valid on type aliases");
         }
+        if let Some((cmp_eq,)) = cmp_eq {
+            errors.error(cmp_eq, "cmp_eq is not valid on type aliases");
+        }
         let generics = if custom_bounds.is_some() {
             MaybeParsed::Unrecognized(generics)
         } else if let Some(generics) = errors.ok(ParsedGenerics::parse(&mut generics)) {
@@ -95,6 +99,7 @@ impl ToTokens for ParsedTypeAlias {
             custom_bounds: _,
             no_static: _,
             no_runtime_generics,
+            cmp_eq: _,
         } = &options.body;
         let target = get_target(target, ident);
         let mut type_attrs = attrs.clone();

crates/fayalite-proc-macros-impl/src/hdl_type_common.rs

@@ -26,6 +26,7 @@ crate::options! {
         CustomBounds(custom_bounds),
         NoStatic(no_static),
         NoRuntimeGenerics(no_runtime_generics),
+        CmpEq(cmp_eq),
     }
 }
 
@@ -2044,6 +2045,7 @@ pub(crate) mod known_items {
     impl_known_item!(::fayalite::int::Size);
     impl_known_item!(::fayalite::int::UInt);
     impl_known_item!(::fayalite::int::UIntType);
+    impl_known_item!(::fayalite::reset::ResetType);
     impl_known_item!(::fayalite::ty::CanonicalType);
     impl_known_item!(::fayalite::ty::StaticType);
     impl_known_item!(::fayalite::ty::Type);
@@ -2068,11 +2070,16 @@ macro_rules! impl_bounds {
             $(
                 $Variant:ident,
             )*
+            $(
+                #[unknown]
+                $Unknown:ident,
+            )?
         }
     ) => {
         #[derive(Clone, Debug)]
         $vis enum $enum_type {
             $($Variant(known_items::$Variant),)*
+            $($Unknown(syn::TypeParamBound),)?
         }
 
         $(impl From<known_items::$Variant> for $enum_type {
@@ -2085,28 +2092,54 @@ macro_rules! impl_bounds {
             fn to_tokens(&self, tokens: &mut TokenStream) {
                 match self {
                     $(Self::$Variant(v) => v.to_tokens(tokens),)*
+                    $(Self::$Unknown(v) => v.to_tokens(tokens),)?
                 }
             }
         }
 
         impl $enum_type {
             $vis fn parse_path(path: Path) -> Result<Self, Path> {
+                #![allow(unreachable_code)]
                 $(let path = match known_items::$Variant::parse_path(path) {
                     Ok(v) => return Ok(Self::$Variant(v)),
                     Err(path) => path,
                 };)*
+                $(return Ok(Self::$Unknown(syn::TraitBound {
+                    paren_token: None,
+                    modifier: syn::TraitBoundModifier::None,
+                    lifetimes: None,
+                    path,
+                }.into()));)?
                 Err(path)
             }
+            $vis fn parse_type_param_bound(mut type_param_bound: syn::TypeParamBound) -> Result<Self, syn::TypeParamBound> {
+                #![allow(unreachable_code)]
+                if let syn::TypeParamBound::Trait(mut trait_bound) = type_param_bound {
+                    if let syn::TraitBound {
+                        paren_token: _,
+                        modifier: syn::TraitBoundModifier::None,
+                        lifetimes: None,
+                        path: _,
+                    } = trait_bound {
+                        match Self::parse_path(trait_bound.path) {
+                            Ok(retval) => return Ok(retval),
+                            Err(path) => trait_bound.path = path,
+                        }
+                    }
+                    type_param_bound = trait_bound.into();
+                }
+                $(return Ok(Self::$Unknown(type_param_bound));)?
+                Err(type_param_bound)
+            }
         }
 
         impl Parse for $enum_type {
             fn parse(input: ParseStream) -> syn::Result<Self> {
-                Self::parse_path(Path::parse_mod_style(input)?).map_err(|path| {
+                Self::parse_type_param_bound(input.parse()?)
-                    syn::Error::new_spanned(
+                    .map_err(|type_param_bound| syn::Error::new_spanned(
-                        path,
+                        type_param_bound,
                         format_args!("expected one of: {}", [$(stringify!($Variant)),*].join(", ")),
-                    )
+                    ))
-                })
             }
         }
 
@@ -2114,6 +2147,7 @@ macro_rules! impl_bounds {
         #[allow(non_snake_case)]
         $vis struct $struct_type {
             $($vis $Variant: Option<known_items::$Variant>,)*
+            $($vis $Unknown: Vec<syn::TypeParamBound>,)?
         }
 
         impl ToTokens for $struct_type {
@@ -2125,42 +2159,63 @@ macro_rules! impl_bounds {
                     separator = Some(<Token![+]>::default());
                     v.to_tokens(tokens);
                 })*
+                $(for v in &self.$Unknown {
+                    separator.to_tokens(tokens);
+                    separator = Some(<Token![+]>::default());
+                    v.to_tokens(tokens);
+                })*
             }
         }
 
         const _: () = {
             #[derive(Clone, Debug)]
-            $vis struct Iter($vis $struct_type);
+            #[allow(non_snake_case)]
+            $vis struct Iter {
+                $($Variant: Option<known_items::$Variant>,)*
+                $($Unknown: std::vec::IntoIter<syn::TypeParamBound>,)?
+            }
 
             impl IntoIterator for $struct_type {
                 type Item = $enum_type;
                 type IntoIter = Iter;
 
                 fn into_iter(self) -> Self::IntoIter {
-                    Iter(self)
+                    Iter {
+                        $($Variant: self.$Variant,)*
+                        $($Unknown: self.$Unknown.into_iter(),)?
+                    }
                 }
             }
 
             impl Iterator for Iter {
                 type Item = $enum_type;
 
-
                 fn next(&mut self) -> Option<Self::Item> {
                     $(
-                        if let Some(value) = self.0.$Variant.take() {
+                        if let Some(value) = self.$Variant.take() {
                             return Some($enum_type::$Variant(value));
                         }
                     )*
+                    $(
+                        if let Some(value) = self.$Unknown.next() {
+                            return Some($enum_type::$Unknown(value));
+                        }
+                    )?
                     None
                 }
 
                 #[allow(unused_mut, unused_variables)]
                 fn fold<B, F: FnMut(B, Self::Item) -> B>(mut self, mut init: B, mut f: F) -> B {
                     $(
-                        if let Some(value) = self.0.$Variant.take() {
+                        if let Some(value) = self.$Variant.take() {
                             init = f(init, $enum_type::$Variant(value));
                         }
                     )*
+                    $(
+                        if let Some(value) = self.$Unknown.next() {
+                            init = f(init, $enum_type::$Unknown(value));
+                        }
+                    )?
                     init
                 }
             }
@@ -2172,6 +2227,9 @@ macro_rules! impl_bounds {
                     $($enum_type::$Variant(v) => {
                         self.$Variant = Some(v);
                     })*
+                    $($enum_type::$Unknown(v) => {
+                        self.$Unknown.push(v);
+                    })?
                 });
             }
         }
@@ -2190,6 +2248,7 @@ macro_rules! impl_bounds {
                     $(if let Some(v) = v.$Variant {
                         self.$Variant = Some(v);
                     })*
+                    $(self.$Unknown.extend(v.$Unknown);)*
                 });
             }
         }
@@ -2239,9 +2298,12 @@ impl_bounds! {
         EnumType,
         IntType,
         KnownSize,
+        ResetType,
         Size,
         StaticType,
         Type,
+        #[unknown]
+        Unknown,
     }
 }
 
@@ -2252,8 +2314,11 @@ impl_bounds! {
         BundleType,
         EnumType,
         IntType,
+        ResetType,
         StaticType,
         Type,
+        #[unknown]
+        Unknown,
     }
 }
 
@@ -2264,8 +2329,10 @@ impl From<ParsedTypeBound> for ParsedBound {
             ParsedTypeBound::BundleType(v) => ParsedBound::BundleType(v),
             ParsedTypeBound::EnumType(v) => ParsedBound::EnumType(v),
             ParsedTypeBound::IntType(v) => ParsedBound::IntType(v),
+            ParsedTypeBound::ResetType(v) => ParsedBound::ResetType(v),
             ParsedTypeBound::StaticType(v) => ParsedBound::StaticType(v),
             ParsedTypeBound::Type(v) => ParsedBound::Type(v),
+            ParsedTypeBound::Unknown(v) => ParsedBound::Unknown(v),
         }
     }
 }
@@ -2277,8 +2344,10 @@ impl From<ParsedTypeBounds> for ParsedBounds {
             BundleType,
             EnumType,
             IntType,
+            ResetType,
             StaticType,
             Type,
+            Unknown,
         } = value;
         Self {
             BoolOrIntType,
@@ -2286,9 +2355,11 @@ impl From<ParsedTypeBounds> for ParsedBounds {
             EnumType,
             IntType,
             KnownSize: None,
+            ResetType,
             Size: None,
             StaticType,
             Type,
+            Unknown,
         }
     }
 }
@@ -2314,11 +2385,17 @@ impl ParsedTypeBound {
                 ParsedTypeBound::BoolOrIntType(known_items::BoolOrIntType(span)),
                 ParsedTypeBound::Type(known_items::Type(span)),
             ]),
+            Self::ResetType(v) => ParsedTypeBounds::from_iter([
+                ParsedTypeBound::from(v),
+                ParsedTypeBound::StaticType(known_items::StaticType(span)),
+                ParsedTypeBound::Type(known_items::Type(span)),
+            ]),
             Self::StaticType(v) => ParsedTypeBounds::from_iter([
                 ParsedTypeBound::from(v),
                 ParsedTypeBound::Type(known_items::Type(span)),
             ]),
             Self::Type(v) => ParsedTypeBounds::from_iter([ParsedTypeBound::from(v)]),
+            Self::Unknown(v) => ParsedTypeBounds::from_iter([ParsedTypeBound::Unknown(v)]),
         }
     }
 }
@@ -2349,9 +2426,11 @@ impl From<ParsedSizeTypeBounds> for ParsedBounds {
             EnumType: None,
             IntType: None,
             KnownSize,
+            ResetType: None,
             Size,
             StaticType: None,
             Type: None,
+            Unknown: vec![],
         }
     }
 }
@@ -2379,6 +2458,7 @@ impl ParsedBounds {
     fn categorize(self, errors: &mut Errors, span: Span) -> ParsedBoundsCategory {
         let mut type_bounds = None;
         let mut size_type_bounds = None;
+        let mut unknown_bounds = vec![];
         self.into_iter().for_each(|bound| match bound.categorize() {
             ParsedBoundCategory::Type(bound) => {
                 type_bounds
@@ -2390,15 +2470,37 @@ impl ParsedBounds {
                     .get_or_insert_with(ParsedSizeTypeBounds::default)
                     .extend([bound]);
             }
+            ParsedBoundCategory::Unknown(bound) => unknown_bounds.push(bound),
         });
-        match (type_bounds, size_type_bounds) {
+        match (type_bounds, size_type_bounds, unknown_bounds.is_empty()) {
-            (None, None) => ParsedBoundsCategory::Type(ParsedTypeBounds {
+            (None, None, true) => ParsedBoundsCategory::Type(ParsedTypeBounds {
                 Type: Some(known_items::Type(span)),
                 ..Default::default()
             }),
-            (None, Some(bounds)) => ParsedBoundsCategory::SizeType(bounds),
+            (None, None, false) => {
-            (Some(bounds), None) => ParsedBoundsCategory::Type(bounds),
+                errors.error(
-            (Some(type_bounds), Some(size_type_bounds)) => {
+                    unknown_bounds.remove(0),
+                    "unknown bounds: must use at least one known bound (such as `Type`) with any unknown bounds",
+                );
+                ParsedBoundsCategory::Type(ParsedTypeBounds {
+                    Unknown: unknown_bounds,
+                    ..Default::default()
+                })
+            }
+            (None, Some(bounds), true) => ParsedBoundsCategory::SizeType(bounds),
+            (None, Some(bounds), false) => {
+                // TODO: implement
+                errors.error(
+                    unknown_bounds.remove(0),
+                    "unknown bounds with `Size` bounds are not implemented",
+                );
+                ParsedBoundsCategory::SizeType(bounds)
+            }
+            (Some(bounds), None, _) => ParsedBoundsCategory::Type(ParsedTypeBounds {
+                Unknown: unknown_bounds,
+                ..bounds
+            }),
+            (Some(type_bounds), Some(size_type_bounds), _) => {
                 errors.error(
                     size_type_bounds
                         .Size
@@ -2415,6 +2517,7 @@ impl ParsedBounds {
 pub(crate) enum ParsedBoundCategory {
     Type(ParsedTypeBound),
     SizeType(ParsedSizeTypeBound),
+    Unknown(syn::TypeParamBound),
 }
 
 impl ParsedBound {
@@ -2425,15 +2528,18 @@ impl ParsedBound {
             Self::EnumType(v) => ParsedBoundCategory::Type(ParsedTypeBound::EnumType(v)),
             Self::IntType(v) => ParsedBoundCategory::Type(ParsedTypeBound::IntType(v)),
             Self::KnownSize(v) => ParsedBoundCategory::SizeType(ParsedSizeTypeBound::KnownSize(v)),
+            Self::ResetType(v) => ParsedBoundCategory::Type(ParsedTypeBound::ResetType(v)),
             Self::Size(v) => ParsedBoundCategory::SizeType(ParsedSizeTypeBound::Size(v)),
             Self::StaticType(v) => ParsedBoundCategory::Type(ParsedTypeBound::StaticType(v)),
             Self::Type(v) => ParsedBoundCategory::Type(ParsedTypeBound::Type(v)),
+            Self::Unknown(v) => ParsedBoundCategory::Unknown(v),
         }
     }
     fn implied_bounds(self) -> ParsedBounds {
         match self.categorize() {
             ParsedBoundCategory::Type(v) => v.implied_bounds().into(),
             ParsedBoundCategory::SizeType(v) => v.implied_bounds().into(),
+            ParsedBoundCategory::Unknown(v) => ParsedBounds::from_iter([ParsedBound::Unknown(v)]),
         }
     }
 }
@@ -3310,8 +3416,9 @@ impl ParsedGenerics {
                                 ParsedTypeBound::BoolOrIntType(_)
                                 | ParsedTypeBound::BundleType(_)
                                 | ParsedTypeBound::EnumType(_)
-                                | ParsedTypeBound::IntType(_) => {
+                                | ParsedTypeBound::IntType(_)
-                                    errors.error(bound, "bound on mask type not implemented");
+                                | ParsedTypeBound::ResetType(_) => {
+                                    errors.error(bound, "bounds on mask types are not implemented");
                                 }
                                 ParsedTypeBound::StaticType(bound) => {
                                     if bounds.StaticType.is_none() {
@@ -3323,6 +3430,12 @@ impl ParsedGenerics {
                                     }
                                 }
                                 ParsedTypeBound::Type(_) => {}
+                                ParsedTypeBound::Unknown(_) => {
+                                    errors.error(
+                                        bound,
+                                        "unknown bounds on mask types are not implemented",
+                                    );
+                                }
                             }
                         }
                         bounds.add_implied_bounds();

crates/fayalite-proc-macros-impl/src/lib.rs

@@ -3,14 +3,20 @@
 #![cfg_attr(test, recursion_limit = "512")]
 use proc_macro2::{Span, TokenStream};
 use quote::{quote, ToTokens};
-use std::io::{ErrorKind, Write};
+use std::{
+    collections::{hash_map::Entry, HashMap},
+    io::{ErrorKind, Write},
+};
 use syn::{
-    bracketed, parenthesized,
+    bracketed,
+    ext::IdentExt,
+    parenthesized,
     parse::{Parse, ParseStream, Parser},
     parse_quote,
-    punctuated::Pair,
+    punctuated::{Pair, Punctuated},
     spanned::Spanned,
-    AttrStyle, Attribute, Error, Item, ItemFn, Token,
+    token::{Bracket, Paren},
+    AttrStyle, Attribute, Error, Ident, Item, ItemFn, LitBool, LitStr, Meta, Token,
 };
 
 mod fold;
@@ -19,6 +25,7 @@ mod hdl_enum;
 mod hdl_type_alias;
 mod hdl_type_common;
 mod module;
+mod process_cfg;
 
 pub(crate) trait CustomToken:
     Copy
@@ -59,14 +66,20 @@ mod kw {
         };
     }
 
+    custom_keyword!(__evaluated_cfgs);
+    custom_keyword!(all);
+    custom_keyword!(any);
+    custom_keyword!(cfg);
+    custom_keyword!(cfg_attr);
     custom_keyword!(clock_domain);
+    custom_keyword!(cmp_eq);
     custom_keyword!(connect_inexact);
     custom_keyword!(custom_bounds);
     custom_keyword!(flip);
     custom_keyword!(hdl);
     custom_keyword!(hdl_module);
-    custom_keyword!(input);
     custom_keyword!(incomplete_wire);
+    custom_keyword!(input);
     custom_keyword!(instance);
     custom_keyword!(m);
     custom_keyword!(memory);
@@ -75,6 +88,7 @@ mod kw {
     custom_keyword!(no_reset);
     custom_keyword!(no_runtime_generics);
     custom_keyword!(no_static);
+    custom_keyword!(not);
     custom_keyword!(outline_generated);
     custom_keyword!(output);
     custom_keyword!(reg_builder);
@@ -901,15 +915,346 @@ fn hdl_module_impl(item: ItemFn) -> syn::Result<TokenStream> {
     Ok(contents)
 }
 
-pub fn hdl_module(attr: TokenStream, item: TokenStream) -> syn::Result<TokenStream> {
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
-    let kw = kw::hdl_module::default();
+pub(crate) enum CfgExpr {
-    hdl_module_impl(syn::parse2(quote! { #[#kw(#attr)] #item })?)
+    Option {
+        ident: Ident,
+        value: Option<(Token![=], LitStr)>,
+    },
+    All {
+        all: kw::all,
+        paren: Paren,
+        exprs: Punctuated<CfgExpr, Token![,]>,
+    },
+    Any {
+        any: kw::any,
+        paren: Paren,
+        exprs: Punctuated<CfgExpr, Token![,]>,
+    },
+    Not {
+        not: kw::not,
+        paren: Paren,
+        expr: Box<CfgExpr>,
+        trailing_comma: Option<Token![,]>,
+    },
 }
 
-pub fn hdl_attr(attr: TokenStream, item: TokenStream) -> syn::Result<TokenStream> {
+impl Parse for CfgExpr {
-    let kw = kw::hdl::default();
+    fn parse(input: ParseStream) -> syn::Result<Self> {
-    let item = quote! { #[#kw(#attr)] #item };
+        match input.cursor().ident() {
-    let item = syn::parse2::<Item>(item)?;
+            Some((_, cursor)) if cursor.eof() => {
+                return Ok(CfgExpr::Option {
+                    ident: input.call(Ident::parse_any)?,
+                    value: None,
+                });
+            }
+            _ => {}
+        }
+        if input.peek(Ident::peek_any) && input.peek2(Token![=]) {
+            return Ok(CfgExpr::Option {
+                ident: input.call(Ident::parse_any)?,
+                value: Some((input.parse()?, input.parse()?)),
+            });
+        }
+        let contents;
+        if input.peek(kw::all) {
+            Ok(CfgExpr::All {
+                all: input.parse()?,
+                paren: parenthesized!(contents in input),
+                exprs: contents.call(Punctuated::parse_terminated)?,
+            })
+        } else if input.peek(kw::any) {
+            Ok(CfgExpr::Any {
+                any: input.parse()?,
+                paren: parenthesized!(contents in input),
+                exprs: contents.call(Punctuated::parse_terminated)?,
+            })
+        } else if input.peek(kw::not) {
+            Ok(CfgExpr::Not {
+                not: input.parse()?,
+                paren: parenthesized!(contents in input),
+                expr: contents.parse()?,
+                trailing_comma: contents.parse()?,
+            })
+        } else {
+            Err(input.error("expected cfg-pattern"))
+        }
+    }
+}
+
+impl ToTokens for CfgExpr {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        match self {
+            CfgExpr::Option { ident, value } => {
+                ident.to_tokens(tokens);
+                if let Some((eq, value)) = value {
+                    eq.to_tokens(tokens);
+                    value.to_tokens(tokens);
+                }
+            }
+            CfgExpr::All { all, paren, exprs } => {
+                all.to_tokens(tokens);
+                paren.surround(tokens, |tokens| exprs.to_tokens(tokens));
+            }
+            CfgExpr::Any { any, paren, exprs } => {
+                any.to_tokens(tokens);
+                paren.surround(tokens, |tokens| exprs.to_tokens(tokens));
+            }
+            CfgExpr::Not {
+                not,
+                paren,
+                expr,
+                trailing_comma,
+            } => {
+                not.to_tokens(tokens);
+                paren.surround(tokens, |tokens| {
+                    expr.to_tokens(tokens);
+                    trailing_comma.to_tokens(tokens);
+                });
+            }
+        }
+    }
+}
+
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+pub(crate) struct Cfg {
+    cfg: kw::cfg,
+    paren: Paren,
+    expr: CfgExpr,
+    trailing_comma: Option<Token![,]>,
+}
+
+impl Cfg {
+    fn parse_meta(meta: &Meta) -> syn::Result<Self> {
+        syn::parse2(meta.to_token_stream())
+    }
+}
+
+impl ToTokens for Cfg {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        let Self {
+            cfg,
+            paren,
+            expr,
+            trailing_comma,
+        } = self;
+        cfg.to_tokens(tokens);
+        paren.surround(tokens, |tokens| {
+            expr.to_tokens(tokens);
+            trailing_comma.to_tokens(tokens);
+        });
+    }
+}
+
+impl Parse for Cfg {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let contents;
+        Ok(Self {
+            cfg: input.parse()?,
+            paren: parenthesized!(contents in input),
+            expr: contents.parse()?,
+            trailing_comma: contents.parse()?,
+        })
+    }
+}
+
+#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+pub(crate) struct CfgAttr {
+    cfg_attr: kw::cfg_attr,
+    paren: Paren,
+    expr: CfgExpr,
+    comma: Token![,],
+    attrs: Punctuated<Meta, Token![,]>,
+}
+
+impl CfgAttr {
+    pub(crate) fn to_cfg(&self) -> Cfg {
+        Cfg {
+            cfg: kw::cfg(self.cfg_attr.span),
+            paren: self.paren,
+            expr: self.expr.clone(),
+            trailing_comma: None,
+        }
+    }
+    fn parse_meta(meta: &Meta) -> syn::Result<Self> {
+        syn::parse2(meta.to_token_stream())
+    }
+}
+
+impl Parse for CfgAttr {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let contents;
+        Ok(Self {
+            cfg_attr: input.parse()?,
+            paren: parenthesized!(contents in input),
+            expr: contents.parse()?,
+            comma: contents.parse()?,
+            attrs: contents.call(Punctuated::parse_terminated)?,
+        })
+    }
+}
+
+pub(crate) struct CfgAndValue {
+    cfg: Cfg,
+    eq_token: Token![=],
+    value: LitBool,
+}
+
+impl Parse for CfgAndValue {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        Ok(Self {
+            cfg: input.parse()?,
+            eq_token: input.parse()?,
+            value: input.parse()?,
+        })
+    }
+}
+
+pub(crate) struct Cfgs<T> {
+    pub(crate) bracket: Bracket,
+    pub(crate) cfgs_map: HashMap<Cfg, T>,
+    pub(crate) cfgs_list: Vec<Cfg>,
+}
+
+impl<T> Default for Cfgs<T> {
+    fn default() -> Self {
+        Self {
+            bracket: Default::default(),
+            cfgs_map: Default::default(),
+            cfgs_list: Default::default(),
+        }
+    }
+}
+
+impl<T> Cfgs<T> {
+    fn insert_cfg(&mut self, cfg: Cfg, value: T) {
+        match self.cfgs_map.entry(cfg) {
+            Entry::Occupied(_) => {}
+            Entry::Vacant(entry) => {
+                self.cfgs_list.push(entry.key().clone());
+                entry.insert(value);
+            }
+        }
+    }
+}
+
+impl Parse for Cfgs<bool> {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let contents;
+        let bracket = bracketed!(contents in input);
+        let mut cfgs_map = HashMap::new();
+        let mut cfgs_list = Vec::new();
+        for CfgAndValue {
+            cfg,
+            eq_token,
+            value,
+        } in contents.call(Punctuated::<CfgAndValue, Token![,]>::parse_terminated)?
+        {
+            let _ = eq_token;
+            match cfgs_map.entry(cfg) {
+                Entry::Occupied(_) => {}
+                Entry::Vacant(entry) => {
+                    cfgs_list.push(entry.key().clone());
+                    entry.insert(value.value);
+                }
+            }
+        }
+        Ok(Self {
+            bracket,
+            cfgs_map,
+            cfgs_list,
+        })
+    }
+}
+
+impl Parse for Cfgs<()> {
+    fn parse(input: ParseStream) -> syn::Result<Self> {
+        let contents;
+        let bracket = bracketed!(contents in input);
+        let mut cfgs_map = HashMap::new();
+        let mut cfgs_list = Vec::new();
+        for cfg in contents.call(Punctuated::<Cfg, Token![,]>::parse_terminated)? {
+            match cfgs_map.entry(cfg) {
+                Entry::Occupied(_) => {}
+                Entry::Vacant(entry) => {
+                    cfgs_list.push(entry.key().clone());
+                    entry.insert(());
+                }
+            }
+        }
+        Ok(Self {
+            bracket,
+            cfgs_map,
+            cfgs_list,
+        })
+    }
+}
+
+impl ToTokens for Cfgs<()> {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        let Self {
+            bracket,
+            cfgs_map: _,
+            cfgs_list,
+        } = self;
+        bracket.surround(tokens, |tokens| {
+            for cfg in cfgs_list {
+                cfg.to_tokens(tokens);
+                <Token![,]>::default().to_tokens(tokens);
+            }
+        });
+    }
+}
+
+fn hdl_main(
+    kw: impl CustomToken,
+    attr: TokenStream,
+    item: TokenStream,
+) -> syn::Result<TokenStream> {
+    fn parse_evaluated_cfgs_attr<R>(
+        input: ParseStream,
+        parse_inner: impl FnOnce(ParseStream) -> syn::Result<R>,
+    ) -> syn::Result<R> {
+        let _: Token![#] = input.parse()?;
+        let bracket_content;
+        bracketed!(bracket_content in input);
+        let _: kw::__evaluated_cfgs = bracket_content.parse()?;
+        let paren_content;
+        parenthesized!(paren_content in bracket_content);
+        parse_inner(&paren_content)
+    }
+    let (evaluated_cfgs, item): (_, TokenStream) = Parser::parse2(
+        |input: ParseStream| {
+            let peek = input.fork();
+            if parse_evaluated_cfgs_attr(&peek, |_| Ok(())).is_ok() {
+                let evaluated_cfgs = parse_evaluated_cfgs_attr(input, Cfgs::<bool>::parse)?;
+                Ok((Some(evaluated_cfgs), input.parse()?))
+            } else {
+                Ok((None, input.parse()?))
+            }
+        },
+        item,
+    )?;
+    let cfgs = if let Some(cfgs) = evaluated_cfgs {
+        cfgs
+    } else {
+        let cfgs = process_cfg::collect_cfgs(syn::parse2(item.clone())?)?;
+        if cfgs.cfgs_list.is_empty() {
+            Cfgs::default()
+        } else {
+            return Ok(quote! {
+                ::fayalite::__cfg_expansion_helper! {
+                    []
+                    #cfgs
+                    {#[::fayalite::#kw(#attr)]} { #item }
+                }
+            });
+        }
+    };
+    let item = syn::parse2(quote! { #[#kw(#attr)] #item })?;
+    let Some(item) = process_cfg::process_cfgs(item, cfgs)? else {
+        return Ok(TokenStream::new());
+    };
     match item {
         Item::Enum(item) => hdl_enum::hdl_enum(item),
         Item::Struct(item) => hdl_bundle::hdl_bundle(item),
@@ -921,3 +1266,11 @@ pub fn hdl_attr(attr: TokenStream, item: TokenStream) -> syn::Result<TokenStream
         )),
     }
 }
+
+pub fn hdl_module(attr: TokenStream, item: TokenStream) -> syn::Result<TokenStream> {
+    hdl_main(kw::hdl_module::default(), attr, item)
+}
+
+pub fn hdl_attr(attr: TokenStream, item: TokenStream) -> syn::Result<TokenStream> {
+    hdl_main(kw::hdl::default(), attr, item)
+}

crates/fayalite-proc-macros-impl/src/module/transform_body.rs

@@ -1109,7 +1109,7 @@ fn parse_quote_let_pat<T, R: ToTokens, C: Borrow<Token![:]>>(
     }
 }
 
-fn wrap_ty_with_expr(ty: impl ToTokens) -> Type {
+pub(crate) fn wrap_ty_with_expr(ty: impl ToTokens) -> Type {
     parse_quote_spanned! {ty.span()=>
         ::fayalite::expr::Expr<#ty>
     }
@@ -1586,7 +1586,7 @@ impl Visitor<'_> {
     }
 }
 
-fn empty_let() -> Local {
+pub(crate) fn empty_let() -> Local {
     Local {
         attrs: vec![],
         let_token: Default::default(),
@@ -1672,7 +1672,7 @@ impl Fold for Visitor<'_> {
         }
     }
 
-    fn fold_local(&mut self, let_stmt: Local) -> Local {
+    fn fold_local(&mut self, mut let_stmt: Local) -> Local {
         match self
             .errors
             .ok(HdlAttr::<Nothing, kw::hdl>::parse_and_leave_attr(
@@ -1682,6 +1682,25 @@ impl Fold for Visitor<'_> {
             Some(None) => return fold_local(self, let_stmt),
             Some(Some(HdlAttr { .. })) => {}
         };
+        let mut pat = &let_stmt.pat;
+        if let Pat::Type(pat_type) = pat {
+            pat = &pat_type.pat;
+        }
+        let Pat::Ident(syn::PatIdent {
+            attrs: _,
+            by_ref: None,
+            mutability: _,
+            ident: _,
+            subpat: None,
+        }) = pat
+        else {
+            let hdl_attr = HdlAttr::<Nothing, kw::hdl>::parse_and_take_attr(&mut let_stmt.attrs)
+                .ok()
+                .flatten()
+                .expect("already checked above");
+            let let_stmt = fold_local(self, let_stmt);
+            return self.process_hdl_let_pat(hdl_attr, let_stmt);
+        };
         let hdl_let = syn::parse2::<HdlLet<HdlLetKind<Type>>>(let_stmt.into_token_stream());
         let Some(hdl_let) = self.errors.ok(hdl_let) else {
             return empty_let();

crates/fayalite-proc-macros-impl/src/module/transform_body/expand_match.rs

@@ -3,22 +3,111 @@
 use crate::{
     fold::{impl_fold, DoFold},
     kw,
-    module::transform_body::{with_debug_clone_and_fold, Visitor},
+    module::transform_body::{empty_let, with_debug_clone_and_fold, wrap_ty_with_expr, Visitor},
     Errors, HdlAttr, PairsIterExt,
 };
 use proc_macro2::{Span, TokenStream};
 use quote::{format_ident, quote_spanned, ToTokens, TokenStreamExt};
+use std::collections::BTreeSet;
 use syn::{
-    fold::{fold_arm, fold_expr_match, fold_pat, Fold},
+    fold::{fold_arm, fold_expr_match, fold_local, fold_pat, Fold},
     parse::Nothing,
     parse_quote_spanned,
     punctuated::Punctuated,
     spanned::Spanned,
     token::{Brace, Paren},
-    Arm, Attribute, Expr, ExprMatch, FieldPat, Ident, Member, Pat, PatIdent, PatOr, PatParen,
+    Arm, Attribute, Expr, ExprMatch, FieldPat, Ident, Local, Member, Pat, PatIdent, PatOr,
-    PatPath, PatRest, PatStruct, PatTupleStruct, PatWild, Path, PathSegment, Token, TypePath,
+    PatParen, PatPath, PatRest, PatStruct, PatTuple, PatTupleStruct, PatWild, Path, PathSegment,
+    Token, TypePath,
 };
 
+macro_rules! visit_trait {
+    (
+        $($vis:vis fn $fn:ident($state:ident: _, $value:ident: &$Value:ty) $block:block)*
+    ) => {
+        trait VisitMatchPat<'a> {
+            $(fn $fn(&mut self, $value: &'a $Value) {
+                $fn(self, $value);
+            })*
+        }
+
+        $($vis fn $fn<'a>($state: &mut (impl ?Sized + VisitMatchPat<'a>), $value: &'a $Value) $block)*
+    };
+}
+
+visit_trait! {
+    fn visit_match_pat_binding(_state: _, v: &MatchPatBinding) {
+        let MatchPatBinding { ident: _ } = v;
+    }
+    fn visit_match_pat_wild(_state: _, v: &MatchPatWild) {
+        let MatchPatWild { underscore_token: _ } = v;
+    }
+    fn visit_match_pat_rest(_state: _, v: &MatchPatRest) {
+        let MatchPatRest { dot2_token: _ } = v;
+    }
+    fn visit_match_pat_paren(state: _, v: &MatchPatParen<MatchPat>) {
+        let MatchPatParen { paren_token: _, pat } = v;
+        state.visit_match_pat(pat);
+    }
+    fn visit_match_pat_paren_simple(state: _, v: &MatchPatParen<MatchPatSimple>) {
+        let MatchPatParen { paren_token: _, pat } = v;
+        state.visit_match_pat_simple(pat);
+    }
+    fn visit_match_pat_or(state: _, v: &MatchPatOr<MatchPat>) {
+        let MatchPatOr { leading_vert: _, cases } = v;
+        for v in cases {
+            state.visit_match_pat(v);
+        }
+    }
+    fn visit_match_pat_or_simple(state: _, v: &MatchPatOr<MatchPatSimple>) {
+        let MatchPatOr { leading_vert: _, cases } = v;
+        for v in cases {
+            state.visit_match_pat_simple(v);
+        }
+    }
+    fn visit_match_pat_struct_field(state: _, v: &MatchPatStructField) {
+        let MatchPatStructField { field_name: _, colon_token: _, pat } = v;
+        state.visit_match_pat_simple(pat);
+    }
+    fn visit_match_pat_struct(state: _, v: &MatchPatStruct) {
+        let MatchPatStruct { match_span: _, path: _, brace_token: _, fields, rest: _ } = v;
+        for v in fields {
+            state.visit_match_pat_struct_field(v);
+        }
+    }
+    fn visit_match_pat_tuple(state: _, v: &MatchPatTuple) {
+        let MatchPatTuple { paren_token: _, fields } = v;
+        for v in fields {
+            state.visit_match_pat_simple(v);
+        }
+    }
+    fn visit_match_pat_enum_variant(state: _, v: &MatchPatEnumVariant) {
+        let MatchPatEnumVariant {match_span:_, variant_path: _, enum_path: _, variant_name: _, field } = v;
+        if let Some((_, v)) = field {
+            state.visit_match_pat_simple(v);
+        }
+    }
+    fn visit_match_pat_simple(state: _, v: &MatchPatSimple) {
+        match v {
+            MatchPatSimple::Paren(v) => state.visit_match_pat_paren_simple(v),
+            MatchPatSimple::Or(v) => state.visit_match_pat_or_simple(v),
+            MatchPatSimple::Binding(v) => state.visit_match_pat_binding(v),
+            MatchPatSimple::Wild(v) => state.visit_match_pat_wild(v),
+            MatchPatSimple::Rest(v) => state.visit_match_pat_rest(v),
+        }
+    }
+    fn visit_match_pat(state: _, v: &MatchPat) {
+        match v {
+            MatchPat::Simple(v) => state.visit_match_pat_simple(v),
+            MatchPat::Or(v) => state.visit_match_pat_or(v),
+            MatchPat::Paren(v) => state.visit_match_pat_paren(v),
+            MatchPat::Struct(v) => state.visit_match_pat_struct(v),
+            MatchPat::Tuple(v) => state.visit_match_pat_tuple(v),
+            MatchPat::EnumVariant(v) => state.visit_match_pat_enum_variant(v),
+        }
+    }
+}
+
 with_debug_clone_and_fold! {
     struct MatchPatBinding<> {
         ident: Ident,
@@ -53,6 +142,15 @@ with_debug_clone_and_fold! {
     }
 }
 
+impl<P> MatchPatOr<P> {
+    /// returns the first `|` between two patterns
+    fn first_inner_vert(&self) -> Option<Token![|]> {
+        let mut pairs = self.cases.pairs();
+        pairs.next_back();
+        pairs.next().and_then(|v| v.into_tuple().1.copied())
+    }
+}
+
 impl<P: ToTokens> ToTokens for MatchPatOr<P> {
     fn to_tokens(&self, tokens: &mut TokenStream) {
         let Self {
@@ -77,6 +175,19 @@ impl ToTokens for MatchPatWild {
     }
 }
 
+with_debug_clone_and_fold! {
+    struct MatchPatRest<> {
+        dot2_token: Token![..],
+    }
+}
+
+impl ToTokens for MatchPatRest {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        let Self { dot2_token } = self;
+        dot2_token.to_tokens(tokens);
+    }
+}
+
 with_debug_clone_and_fold! {
     struct MatchPatStructField<> {
         field_name: Ident,
@@ -159,6 +270,25 @@ impl ToTokens for MatchPatStruct {
     }
 }
 
+with_debug_clone_and_fold! {
+    struct MatchPatTuple<> {
+        paren_token: Paren,
+        fields: Punctuated<MatchPatSimple, Token![,]>,
+    }
+}
+
+impl ToTokens for MatchPatTuple {
+    fn to_tokens(&self, tokens: &mut TokenStream) {
+        let Self {
+            paren_token,
+            fields,
+        } = self;
+        paren_token.surround(tokens, |tokens| {
+            fields.to_tokens(tokens);
+        })
+    }
+}
+
 with_debug_clone_and_fold! {
     struct MatchPatEnumVariant<> {
         match_span: Span,
@@ -194,6 +324,7 @@ enum MatchPatSimple {
     Or(MatchPatOr<MatchPatSimple>),
     Binding(MatchPatBinding),
     Wild(MatchPatWild),
+    Rest(MatchPatRest),
 }
 
 impl_fold! {
@@ -202,6 +333,7 @@ impl_fold! {
         Or(MatchPatOr<MatchPatSimple>),
         Binding(MatchPatBinding),
         Wild(MatchPatWild),
+        Rest(MatchPatRest),
     }
 }
 
@@ -212,6 +344,7 @@ impl ToTokens for MatchPatSimple {
             Self::Paren(v) => v.to_tokens(tokens),
             Self::Binding(v) => v.to_tokens(tokens),
             Self::Wild(v) => v.to_tokens(tokens),
+            Self::Rest(v) => v.to_tokens(tokens),
         }
     }
 }
@@ -278,6 +411,7 @@ trait ParseMatchPat: Sized {
     fn or(v: MatchPatOr<Self>) -> Self;
     fn paren(v: MatchPatParen<Self>) -> Self;
     fn struct_(state: &mut HdlMatchParseState<'_>, v: MatchPatStruct) -> Result<Self, ()>;
+    fn tuple(state: &mut HdlMatchParseState<'_>, v: MatchPatTuple) -> Result<Self, ()>;
     fn enum_variant(state: &mut HdlMatchParseState<'_>, v: MatchPatEnumVariant)
         -> Result<Self, ()>;
     fn parse(state: &mut HdlMatchParseState<'_>, pat: Pat) -> Result<Self, ()> {
@@ -462,7 +596,34 @@ trait ParseMatchPat: Sized {
             }) => Ok(Self::simple(MatchPatSimple::Wild(MatchPatWild {
                 underscore_token,
             }))),
-            Pat::Tuple(_) | Pat::Slice(_) | Pat::Const(_) | Pat::Lit(_) | Pat::Range(_) => {
+            Pat::Tuple(PatTuple {
+                attrs: _,
+                paren_token,
+                elems,
+            }) => {
+                let fields = elems
+                    .into_pairs()
+                    .filter_map_pair_value(|field_pat| {
+                        if let Pat::Rest(PatRest {
+                            attrs: _,
+                            dot2_token,
+                        }) = field_pat
+                        {
+                            Some(MatchPatSimple::Rest(MatchPatRest { dot2_token }))
+                        } else {
+                            MatchPatSimple::parse(state, field_pat).ok()
+                        }
+                    })
+                    .collect();
+                Self::tuple(
+                    state,
+                    MatchPatTuple {
+                        paren_token,
+                        fields,
+                    },
+                )
+            }
+            Pat::Slice(_) | Pat::Const(_) | Pat::Lit(_) | Pat::Range(_) => {
                 state
                     .errors
                     .error(pat, "not yet implemented in #[hdl] patterns");
@@ -497,6 +658,14 @@ impl ParseMatchPat for MatchPatSimple {
         Err(())
     }
 
+    fn tuple(state: &mut HdlMatchParseState<'_>, v: MatchPatTuple) -> Result<Self, ()> {
+        state.errors.push(syn::Error::new(
+            v.paren_token.span.open(),
+            "matching tuples is not yet implemented inside structs/enums in #[hdl] patterns",
+        ));
+        Err(())
+    }
+
     fn enum_variant(
         state: &mut HdlMatchParseState<'_>,
         v: MatchPatEnumVariant,
@@ -515,6 +684,7 @@ enum MatchPat {
     Or(MatchPatOr<MatchPat>),
     Paren(MatchPatParen<MatchPat>),
     Struct(MatchPatStruct),
+    Tuple(MatchPatTuple),
     EnumVariant(MatchPatEnumVariant),
 }
 
@@ -524,6 +694,7 @@ impl_fold! {
         Or(MatchPatOr<MatchPat>),
         Paren(MatchPatParen<MatchPat>),
         Struct(MatchPatStruct),
+        Tuple(MatchPatTuple),
         EnumVariant(MatchPatEnumVariant),
     }
 }
@@ -545,6 +716,10 @@ impl ParseMatchPat for MatchPat {
         Ok(Self::Struct(v))
     }
 
+    fn tuple(_state: &mut HdlMatchParseState<'_>, v: MatchPatTuple) -> Result<Self, ()> {
+        Ok(Self::Tuple(v))
+    }
+
     fn enum_variant(
         _state: &mut HdlMatchParseState<'_>,
         v: MatchPatEnumVariant,
@@ -560,6 +735,7 @@ impl ToTokens for MatchPat {
             Self::Or(v) => v.to_tokens(tokens),
             Self::Paren(v) => v.to_tokens(tokens),
             Self::Struct(v) => v.to_tokens(tokens),
+            Self::Tuple(v) => v.to_tokens(tokens),
             Self::EnumVariant(v) => v.to_tokens(tokens),
         }
     }
@@ -622,10 +798,6 @@ struct RewriteAsCheckMatch {
 }
 
 impl Fold for RewriteAsCheckMatch {
-    fn fold_field_pat(&mut self, mut i: FieldPat) -> FieldPat {
-        i.colon_token = Some(Token![:](i.member.span()));
-        i
-    }
     fn fold_pat(&mut self, pat: Pat) -> Pat {
         match pat {
             Pat::Ident(mut pat_ident) => match parse_enum_ident(pat_ident.ident) {
@@ -740,6 +912,30 @@ impl Fold for RewriteAsCheckMatch {
         // don't recurse into expressions
         i
     }
+    fn fold_local(&mut self, mut let_stmt: Local) -> Local {
+        if let Some(syn::LocalInit {
+            eq_token,
+            expr: _,
+            diverge,
+        }) = let_stmt.init.take()
+        {
+            let_stmt.init = Some(syn::LocalInit {
+                eq_token,
+                expr: parse_quote_spanned! {self.span=>
+                    __match_value
+                },
+                diverge: diverge.map(|(else_, _expr)| {
+                    (
+                        else_,
+                        parse_quote_spanned! {self.span=>
+                            match __infallible {}
+                        },
+                    )
+                }),
+            });
+        }
+        fold_local(self, let_stmt)
+    }
 }
 
 struct HdlMatchParseState<'a> {
@@ -747,7 +943,123 @@ struct HdlMatchParseState<'a> {
     errors: &'a mut Errors,
 }
 
+struct HdlLetPatVisitState<'a> {
+    errors: &'a mut Errors,
+    bindings: BTreeSet<&'a Ident>,
+}
+
+impl<'a> VisitMatchPat<'a> for HdlLetPatVisitState<'a> {
+    fn visit_match_pat_binding(&mut self, v: &'a MatchPatBinding) {
+        self.bindings.insert(&v.ident);
+    }
+
+    fn visit_match_pat_or(&mut self, v: &'a MatchPatOr<MatchPat>) {
+        if let Some(first_inner_vert) = v.first_inner_vert() {
+            self.errors.error(
+                first_inner_vert,
+                "or-patterns are not supported in let statements",
+            );
+        }
+        visit_match_pat_or(self, v);
+    }
+
+    fn visit_match_pat_or_simple(&mut self, v: &'a MatchPatOr<MatchPatSimple>) {
+        if let Some(first_inner_vert) = v.first_inner_vert() {
+            self.errors.error(
+                first_inner_vert,
+                "or-patterns are not supported in let statements",
+            );
+        }
+        visit_match_pat_or_simple(self, v);
+    }
+
+    fn visit_match_pat_enum_variant(&mut self, v: &'a MatchPatEnumVariant) {
+        self.errors.error(v, "refutable pattern in let statement");
+    }
+}
+
 impl Visitor<'_> {
+    pub(crate) fn process_hdl_let_pat(
+        &mut self,
+        _hdl_attr: HdlAttr<Nothing, kw::hdl>,
+        mut let_stmt: Local,
+    ) -> Local {
+        let span = let_stmt.let_token.span();
+        if let Pat::Type(pat) = &mut let_stmt.pat {
+            *pat.ty = wrap_ty_with_expr((*pat.ty).clone());
+        }
+        let check_let_stmt = RewriteAsCheckMatch { span }.fold_local(let_stmt.clone());
+        let Local {
+            attrs: _,
+            let_token,
+            pat,
+            init,
+            semi_token,
+        } = let_stmt;
+        self.require_normal_module_or_fn(let_token);
+        let Some(syn::LocalInit {
+            eq_token,
+            expr,
+            diverge,
+        }) = init
+        else {
+            self.errors
+                .error(let_token, "#[hdl] let must be assigned a value");
+            return empty_let();
+        };
+        if let Some((else_, _)) = diverge {
+            // TODO: implement let-else
+            self.errors
+                .error(else_, "#[hdl] let ... else { ... } is not implemented");
+            return empty_let();
+        }
+        let Ok(pat) = MatchPat::parse(
+            &mut HdlMatchParseState {
+                match_span: span,
+                errors: &mut self.errors,
+            },
+            pat,
+        ) else {
+            return empty_let();
+        };
+        let mut state = HdlLetPatVisitState {
+            errors: &mut self.errors,
+            bindings: BTreeSet::new(),
+        };
+        state.visit_match_pat(&pat);
+        let HdlLetPatVisitState {
+            errors: _,
+            bindings,
+        } = state;
+        let retval = parse_quote_spanned! {span=>
+            let (#(#bindings,)* __scope,) = {
+                type __MatchTy<T> = <T as ::fayalite::ty::Type>::MatchVariant;
+                let __match_expr = ::fayalite::expr::ToExpr::to_expr(&(#expr));
+                ::fayalite::expr::check_match_expr(__match_expr, |__match_value, __infallible| {
+                    #[allow(unused_variables)]
+                    #check_let_stmt
+                    match __infallible {}
+                });
+                let mut __match_iter = ::fayalite::module::match_(__match_expr);
+                let ::fayalite::__std::option::Option::Some(__match_variant) = ::fayalite::__std::iter::Iterator::next(&mut __match_iter) else {
+                    ::fayalite::__std::unreachable!("#[hdl] let with uninhabited type");
+                };
+                let ::fayalite::__std::option::Option::None = ::fayalite::__std::iter::Iterator::next(&mut __match_iter) else {
+                    ::fayalite::__std::unreachable!("#[hdl] let with refutable pattern");
+                };
+                let (__match_variant, __scope) =
+                    ::fayalite::ty::MatchVariantAndInactiveScope::match_activate_scope(
+                        __match_variant,
+                    );
+                #let_token #pat #eq_token __match_variant #semi_token
+                (#(#bindings,)* __scope,)
+            };
+        };
+        match retval {
+            syn::Stmt::Local(retval) => retval,
+            _ => unreachable!(),
+        }
+    }
     pub(crate) fn process_hdl_match(
         &mut self,
         _hdl_attr: HdlAttr<Nothing, kw::hdl>,

crates/fayalite/Cargo.toml

@@ -25,9 +25,11 @@ jobslot.workspace = true
 num-bigint.workspace = true
 num-traits.workspace = true
 os_pipe.workspace = true
+petgraph.workspace = true
 serde_json.workspace = true
 serde.workspace = true
 tempfile.workspace = true
+vec_map.workspace = true
 which.workspace = true
 
 [dev-dependencies]

crates/fayalite/build.rs

@@ -5,6 +5,9 @@ use std::{env, fs, path::Path};
 
 fn main() {
     println!("cargo::rustc-check-cfg=cfg(todo)");
+    println!("cargo::rustc-check-cfg=cfg(cfg_false_for_tests)");
+    println!("cargo::rustc-check-cfg=cfg(cfg_true_for_tests)");
+    println!("cargo::rustc-cfg=cfg_true_for_tests");
     let path = "visit_types.json";
     println!("cargo::rerun-if-changed={path}");
     println!("cargo::rerun-if-changed=build.rs");

crates/fayalite/src/_docs/modules/module_bodies/hdl_let_statements.rs

@@ -2,6 +2,7 @@
 // See Notices.txt for copyright information
 //! ## `#[hdl] let` statements
 
+pub mod destructuring;
 pub mod inputs_outputs;
 pub mod instances;
 pub mod memories;

crates/fayalite/src/_docs/modules/module_bodies/hdl_let_statements/destructuring.rs

@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+// See Notices.txt for copyright information
+//! ### Destructuring Let
+//!
+//! You can use `#[hdl] let` to destructure types, similarly to Rust `let` statements with non-trivial patterns.
+//!
+//! `#[hdl] let` statements can only match one level of struct/tuple pattern for now,
+//! e.g. you can match with the pattern `MyStruct { a, b }`, but not `MyStruct { a, b: Struct2 { v } }`.
+//!
+//! ```
+//! # use fayalite::prelude::*;
+//! #[hdl]
+//! struct MyStruct {
+//!     a: UInt<8>,
+//!     b: Bool,
+//! }
+//!
+//! #[hdl_module]
+//! fn my_module() {
+//!     #[hdl]
+//!     let my_input: MyStruct = m.input();
+//!     #[hdl]
+//!     let my_output: UInt<8> = m.input();
+//!     #[hdl]
+//!     let MyStruct { a, b } = my_input;
+//!     #[hdl]
+//!     if b {
+//!         connect(my_output, a);
+//!     } else {
+//!         connect(my_output, 0_hdl_u8);
+//!     }
+//! }
+//! ```

crates/fayalite/src/_docs/modules/module_bodies/hdl_match_statements.rs

@@ -7,5 +7,5 @@
 //!
 //! `#[hdl] match` statements' bodies must evaluate to type `()` for now.
 //!
-//! `#[hdl] match` statements can only match one level of struct/enum pattern for now,
+//! `#[hdl] match` statements can only match one level of struct/tuple/enum pattern for now,
 //! e.g. you can match with the pattern `HdlSome(v)`, but not `HdlSome(HdlSome(_))`.

crates/fayalite/src/array.rs

@@ -2,8 +2,11 @@
 // See Notices.txt for copyright information
 
 use crate::{
-    expr::{ops::ArrayIndex, Expr, ToExpr},
+    expr::{
-    int::{DynSize, KnownSize, Size, SizeType, DYN_SIZE},
+        ops::{ArrayIndex, ArrayLiteral, ExprPartialEq},
+        CastToBits, Expr, HdlPartialEq, ReduceBits, ToExpr,
+    },
+    int::{Bool, DynSize, KnownSize, Size, SizeType, DYN_SIZE},
     intern::{Intern, Interned, LazyInterned},
     module::transform::visit::{Fold, Folder, Visit, Visitor},
     source_location::SourceLocation,
@@ -218,3 +221,36 @@ impl<T: Type, L: SizeType> Index<L> for ArrayWithoutLen<T> {
         Interned::into_inner(Intern::intern_sized(ArrayType::new(self.element, len)))
     }
 }
+
+impl<Lhs: Type, Rhs: Type, Len: Size> ExprPartialEq<ArrayType<Rhs, Len>> for ArrayType<Lhs, Len>
+where
+    Lhs: ExprPartialEq<Rhs>,
+{
+    fn cmp_eq(lhs: Expr<Self>, rhs: Expr<ArrayType<Rhs, Len>>) -> Expr<Bool> {
+        let lhs_ty = Expr::ty(lhs);
+        let rhs_ty = Expr::ty(rhs);
+        assert_eq!(lhs_ty.len(), rhs_ty.len());
+        ArrayLiteral::<Bool, DynSize>::new(
+            Bool,
+            (0..lhs_ty.len())
+                .map(|i| Expr::canonical(lhs[i].cmp_eq(rhs[i])))
+                .collect(),
+        )
+        .cast_to_bits()
+        .all_one_bits()
+    }
+
+    fn cmp_ne(lhs: Expr<Self>, rhs: Expr<ArrayType<Rhs, Len>>) -> Expr<Bool> {
+        let lhs_ty = Expr::ty(lhs);
+        let rhs_ty = Expr::ty(rhs);
+        assert_eq!(lhs_ty.len(), rhs_ty.len());
+        ArrayLiteral::<Bool, DynSize>::new(
+            Bool,
+            (0..lhs_ty.len())
+                .map(|i| Expr::canonical(lhs[i].cmp_ne(rhs[i])))
+                .collect(),
+        )
+        .cast_to_bits()
+        .any_one_bits()
+    }
+}

crates/fayalite/src/bundle.rs

@@ -2,14 +2,20 @@
 // See Notices.txt for copyright information
 
 use crate::{
-    expr::{ops::BundleLiteral, Expr, ToExpr},
+    expr::{
+        ops::{ArrayLiteral, BundleLiteral, ExprPartialEq},
+        CastToBits, Expr, ReduceBits, ToExpr,
+    },
+    int::{Bool, DynSize},
     intern::{Intern, Interned},
+    sim::{SimValue, ToSimValue},
     source_location::SourceLocation,
     ty::{
         impl_match_variant_as_self, CanonicalType, MatchVariantWithoutScope, StaticType, Type,
         TypeProperties, TypeWithDeref,
     },
 };
+use bitvec::vec::BitVec;
 use hashbrown::HashMap;
 use std::{fmt, marker::PhantomData};
 
@@ -323,7 +329,19 @@ macro_rules! impl_tuple_builder_fields {
 }
 
 macro_rules! impl_tuples {
-    ([$({#[num = $num:literal, field = $field:ident] $var:ident: $T:ident})*] []) => {
+    (
+        [$({
+            #[
+                num = $num:tt,
+                field = $field:ident,
+                ty = $ty_var:ident: $Ty:ident,
+                lhs = $lhs_var:ident: $Lhs:ident,
+                rhs = $rhs_var:ident: $Rhs:ident
+            ]
+            $var:ident: $T:ident
+        })*]
+        []
+    ) => {
         impl_tuple_builder_fields! {
             {}
             [$({
@@ -423,6 +441,102 @@ macro_rules! impl_tuples {
                 BundleLiteral::new(ty, field_values[..].intern()).to_expr()
             }
         }
+        impl<$($T: ToSimValue<CanonicalType>,)*> ToSimValue<CanonicalType> for ($($T,)*) {
+            #[track_caller]
+            fn to_sim_value(&self, ty: CanonicalType) -> SimValue<CanonicalType> {
+                ToSimValue::<Bundle>::to_sim_value(self, Bundle::from_canonical(ty)).into_canonical()
+            }
+            #[track_caller]
+            fn into_sim_value(self, ty: CanonicalType) -> SimValue<CanonicalType>
+            {
+                ToSimValue::<Bundle>::into_sim_value(self, Bundle::from_canonical(ty)).into_canonical()
+            }
+            #[track_caller]
+            fn box_into_sim_value(self: Box<Self>, ty: CanonicalType) -> SimValue<CanonicalType> {
+                ToSimValue::<Bundle>::box_into_sim_value(self, Bundle::from_canonical(ty)).into_canonical()
+            }
+        }
+        impl<$($T: ToSimValue<CanonicalType>,)*> ToSimValue<Bundle> for ($($T,)*) {
+            #[track_caller]
+            fn to_sim_value(&self, ty: Bundle) -> SimValue<Bundle> {
+                let ($($var,)*) = self;
+                let [$($ty_var,)*] = *ty.fields() else {
+                    panic!("bundle has wrong number of fields");
+                };
+                $(let $var = $var.to_sim_value($ty_var.ty);)*
+                ToSimValue::into_sim_value(($($var,)*), ty)
+            }
+            #[track_caller]
+            fn into_sim_value(self, ty: Bundle) -> SimValue<Bundle> {
+                #![allow(unused_mut)]
+                #![allow(clippy::unused_unit)]
+                let ($($var,)*) = self;
+                let [$($ty_var,)*] = *ty.fields() else {
+                    panic!("bundle has wrong number of fields");
+                };
+                let mut bits: Option<BitVec> = None;
+                $(let $var = $var.into_sim_value($ty_var.ty);
+                assert_eq!($var.ty(), $ty_var.ty);
+                if !$var.bits().is_empty() {
+                    if let Some(bits) = &mut bits {
+                        bits.extend_from_bitslice($var.bits());
+                    } else {
+                        let mut $var = $var.into_bits();
+                        $var.reserve(ty.type_properties().bit_width - $var.len());
+                        bits = Some($var);
+                    }
+                }
+                )*
+                bits.unwrap_or_else(BitVec::new).into_sim_value(ty)
+            }
+            #[track_caller]
+            fn box_into_sim_value(self: Box<Self>, ty: Bundle) -> SimValue<Bundle> {
+                Self::into_sim_value(*self, ty)
+            }
+        }
+        impl<$($T: ToSimValue<$Ty>, $Ty: Type,)*> ToSimValue<($($Ty,)*)> for ($($T,)*) {
+            #[track_caller]
+            fn to_sim_value(&self, ty: ($($Ty,)*)) -> SimValue<($($Ty,)*)> {
+                let ($($var,)*) = self;
+                let ($($ty_var,)*) = ty;
+                $(let $var = $var.to_sim_value($ty_var).into_canonical();)*
+                SimValue::from_canonical(ToSimValue::into_sim_value(($($var,)*), ty.canonical()))
+            }
+            #[track_caller]
+            fn into_sim_value(self, ty: ($($Ty,)*)) -> SimValue<($($Ty,)*)> {
+                let ($($var,)*) = self;
+                let ($($ty_var,)*) = ty;
+                $(let $var = $var.into_sim_value($ty_var).into_canonical();)*
+                SimValue::from_canonical(ToSimValue::into_sim_value(($($var,)*), ty.canonical()))
+            }
+            #[track_caller]
+            fn box_into_sim_value(self: Box<Self>, ty: ($($Ty,)*)) -> SimValue<($($Ty,)*)> {
+                Self::into_sim_value(*self, ty)
+            }
+        }
+        impl<$($Lhs: Type + ExprPartialEq<$Rhs>, $Rhs: Type,)*> ExprPartialEq<($($Rhs,)*)> for ($($Lhs,)*) {
+            fn cmp_eq(lhs: Expr<Self>, rhs: Expr<($($Rhs,)*)>) -> Expr<Bool> {
+                let ($($lhs_var,)*) = *lhs;
+                let ($($rhs_var,)*) = *rhs;
+                ArrayLiteral::<Bool, DynSize>::new(
+                    Bool,
+                    FromIterator::from_iter([$(Expr::canonical(ExprPartialEq::cmp_eq($lhs_var, $rhs_var)),)*]),
+                )
+                .cast_to_bits()
+                .all_one_bits()
+            }
+
+            fn cmp_ne(lhs: Expr<Self>, rhs: Expr<($($Rhs,)*)>) -> Expr<Bool> {
+                let ($($lhs_var,)*) = *lhs;
+                let ($($rhs_var,)*) = *rhs;
+                ArrayLiteral::<Bool, DynSize>::new(
+                    Bool,
+                    FromIterator::from_iter([$(Expr::canonical(ExprPartialEq::cmp_ne($lhs_var, $rhs_var)),)*]),
+                )
+                .cast_to_bits()
+                .any_one_bits()
+            }
+        }
     };
     ([$($lhs:tt)*] [$rhs_first:tt $($rhs:tt)*]) => {
         impl_tuples!([$($lhs)*] []);
@@ -432,18 +546,18 @@ macro_rules! impl_tuples {
 
 impl_tuples! {
     [] [
-        {#[num = 0, field = field_0] v0: T0}
+        {#[num = 0, field = field_0, ty = ty0: Ty0, lhs = lhs0: Lhs0, rhs = rhs0: Rhs0] v0: T0}
-        {#[num = 1, field = field_1] v1: T1}
+        {#[num = 1, field = field_1, ty = ty1: Ty1, lhs = lhs1: Lhs1, rhs = rhs1: Rhs1] v1: T1}
-        {#[num = 2, field = field_2] v2: T2}
+        {#[num = 2, field = field_2, ty = ty2: Ty2, lhs = lhs2: Lhs2, rhs = rhs2: Rhs2] v2: T2}
-        {#[num = 3, field = field_3] v3: T3}
+        {#[num = 3, field = field_3, ty = ty3: Ty3, lhs = lhs3: Lhs3, rhs = rhs3: Rhs3] v3: T3}
-        {#[num = 4, field = field_4] v4: T4}
+        {#[num = 4, field = field_4, ty = ty4: Ty4, lhs = lhs4: Lhs4, rhs = rhs4: Rhs4] v4: T4}
-        {#[num = 5, field = field_5] v5: T5}
+        {#[num = 5, field = field_5, ty = ty5: Ty5, lhs = lhs5: Lhs5, rhs = rhs5: Rhs5] v5: T5}
-        {#[num = 6, field = field_6] v6: T6}
+        {#[num = 6, field = field_6, ty = ty6: Ty6, lhs = lhs6: Lhs6, rhs = rhs6: Rhs6] v6: T6}
-        {#[num = 7, field = field_7] v7: T7}
+        {#[num = 7, field = field_7, ty = ty7: Ty7, lhs = lhs7: Lhs7, rhs = rhs7: Rhs7] v7: T7}
-        {#[num = 8, field = field_8] v8: T8}
+        {#[num = 8, field = field_8, ty = ty8: Ty8, lhs = lhs8: Lhs8, rhs = rhs8: Rhs8] v8: T8}
-        {#[num = 9, field = field_9] v9: T9}
+        {#[num = 9, field = field_9, ty = ty9: Ty9, lhs = lhs9: Lhs9, rhs = rhs9: Rhs9] v9: T9}
-        {#[num = 10, field = field_10] v10: T10}
+        {#[num = 10, field = field_10, ty = ty10: Ty10, lhs = lhs10: Lhs10, rhs = rhs10: Rhs10] v10: T10}
-        {#[num = 11, field = field_11] v11: T11}
+        {#[num = 11, field = field_11, ty = ty11: Ty11, lhs = lhs11: Lhs11, rhs = rhs11: Rhs11] v11: T11}
     ]
 }
 
@@ -528,3 +642,27 @@ impl<T: ?Sized + Send + Sync + 'static> ToExpr for PhantomData<T> {
         BundleLiteral::new(PhantomData, Interned::default()).to_expr()
     }
 }
+
+impl<T: ?Sized + Send + Sync + 'static> ToSimValue<Self> for PhantomData<T> {
+    #[track_caller]
+    fn to_sim_value(&self, ty: Self) -> SimValue<Self> {
+        ToSimValue::into_sim_value(BitVec::new(), ty)
+    }
+}
+
+impl<T: ?Sized> ToSimValue<Bundle> for PhantomData<T> {
+    #[track_caller]
+    fn to_sim_value(&self, ty: Bundle) -> SimValue<Bundle> {
+        assert!(ty.fields().is_empty());
+        ToSimValue::into_sim_value(BitVec::new(), ty)
+    }
+}
+
+impl<T: ?Sized> ToSimValue<CanonicalType> for PhantomData<T> {
+    #[track_caller]
+    fn to_sim_value(&self, ty: CanonicalType) -> SimValue<CanonicalType> {
+        let ty = Bundle::from_canonical(ty);
+        assert!(ty.fields().is_empty());
+        ToSimValue::into_sim_value(BitVec::new(), ty).into_canonical()
+    }
+}

crates/fayalite/src/clock.rs

@@ -4,7 +4,7 @@ use crate::{
     expr::{Expr, ToExpr},
     hdl,
     int::Bool,
-    reset::Reset,
+    reset::{Reset, ResetType},
     source_location::SourceLocation,
     ty::{impl_match_variant_as_self, CanonicalType, StaticType, Type, TypeProperties},
 };
@@ -88,9 +88,9 @@ impl ToClock for Expr<Clock> {
 }
 
 #[hdl]
-pub struct ClockDomain {
+pub struct ClockDomain<R: ResetType = Reset> {
     pub clk: Clock,
-    pub rst: Reset,
+    pub rst: R,
 }
 
 impl ToClock for bool {

crates/fayalite/src/enum_.rs

@@ -2,7 +2,10 @@
 // See Notices.txt for copyright information
 
 use crate::{
-    expr::{ops::VariantAccess, Expr, ToExpr},
+    expr::{
+        ops::{ExprPartialEq, VariantAccess},
+        Expr, ToExpr,
+    },
     hdl,
     int::Bool,
     intern::{Intern, Interned},
@@ -360,6 +363,60 @@ pub enum HdlOption<T: Type> {
     HdlSome(T),
 }
 
+impl<Lhs: Type + ExprPartialEq<Rhs>, Rhs: Type> ExprPartialEq<HdlOption<Rhs>> for HdlOption<Lhs> {
+    #[hdl]
+    fn cmp_eq(lhs: Expr<Self>, rhs: Expr<HdlOption<Rhs>>) -> Expr<Bool> {
+        #[hdl]
+        let cmp_eq = wire();
+        #[hdl]
+        match lhs {
+            HdlSome(lhs) =>
+            {
+                #[hdl]
+                match rhs {
+                    HdlSome(rhs) => connect(cmp_eq, ExprPartialEq::cmp_eq(lhs, rhs)),
+                    HdlNone => connect(cmp_eq, false),
+                }
+            }
+            HdlNone =>
+            {
+                #[hdl]
+                match rhs {
+                    HdlSome(_) => connect(cmp_eq, false),
+                    HdlNone => connect(cmp_eq, true),
+                }
+            }
+        }
+        cmp_eq
+    }
+
+    #[hdl]
+    fn cmp_ne(lhs: Expr<Self>, rhs: Expr<HdlOption<Rhs>>) -> Expr<Bool> {
+        #[hdl]
+        let cmp_ne = wire();
+        #[hdl]
+        match lhs {
+            HdlSome(lhs) =>
+            {
+                #[hdl]
+                match rhs {
+                    HdlSome(rhs) => connect(cmp_ne, ExprPartialEq::cmp_ne(lhs, rhs)),
+                    HdlNone => connect(cmp_ne, true),
+                }
+            }
+            HdlNone =>
+            {
+                #[hdl]
+                match rhs {
+                    HdlSome(_) => connect(cmp_ne, true),
+                    HdlNone => connect(cmp_ne, false),
+                }
+            }
+        }
+        cmp_ne
+    }
+}
+
 #[allow(non_snake_case)]
 pub fn HdlNone<T: StaticType>() -> Expr<HdlOption<T>> {
     HdlOption[T::TYPE].HdlNone()

crates/fayalite/src/expr.rs

@@ -17,6 +17,7 @@ use crate::{
         Instance, ModuleIO,
     },
     reg::Reg,
+    reset::{AsyncReset, Reset, ResetType, ResetTypeDispatch, SyncReset},
     ty::{CanonicalType, StaticType, Type, TypeWithDeref},
     wire::Wire,
 };
@@ -209,7 +210,9 @@ expr_enum! {
         ModuleIO(ModuleIO<CanonicalType>),
         Instance(Instance<Bundle>),
         Wire(Wire<CanonicalType>),
-        Reg(Reg<CanonicalType>),
+        Reg(Reg<CanonicalType, Reset>),
+        RegSync(Reg<CanonicalType, SyncReset>),
+        RegAsync(Reg<CanonicalType, AsyncReset>),
         MemPort(MemPort<DynPortType>),
     }
 }
@@ -593,25 +596,42 @@ impl<T: Type> GetTarget for Wire<T> {
     }
 }
 
-impl<T: Type> ToExpr for Reg<T> {
+impl<T: Type, R: ResetType> ToExpr for Reg<T, R> {
     type Type = T;
 
     fn to_expr(&self) -> Expr<Self::Type> {
+        struct Dispatch;
+        impl ResetTypeDispatch for Dispatch {
+            type Input<T: ResetType> = Reg<CanonicalType, T>;
+            type Output<T: ResetType> = ExprEnum;
+
+            fn reset(self, input: Self::Input<Reset>) -> Self::Output<Reset> {
+                ExprEnum::Reg(input)
+            }
+
+            fn sync_reset(self, input: Self::Input<SyncReset>) -> Self::Output<SyncReset> {
+                ExprEnum::RegSync(input)
+            }
+
+            fn async_reset(self, input: Self::Input<AsyncReset>) -> Self::Output<AsyncReset> {
+                ExprEnum::RegAsync(input)
+            }
+        }
         Expr {
-            __enum: ExprEnum::Reg(self.canonical()).intern_sized(),
+            __enum: R::dispatch(self.canonical(), Dispatch).intern_sized(),
             __ty: self.ty(),
             __flow: self.flow(),
         }
     }
 }
 
-impl<T: Type> ToLiteralBits for Reg<T> {
+impl<T: Type, R: ResetType> ToLiteralBits for Reg<T, R> {
     fn to_literal_bits(&self) -> Result<Interned<BitSlice>, NotALiteralExpr> {
         Err(NotALiteralExpr)
     }
 }
 
-impl<T: Type> GetTarget for Reg<T> {
+impl<T: Type, R: ResetType> GetTarget for Reg<T, R> {
     fn target(&self) -> Option<Interned<Target>> {
         Some(Intern::intern_sized(self.canonical().into()))
     }

crates/fayalite/src/expr/ops.rs

@@ -19,7 +19,10 @@ use crate::{
         UIntType, UIntValue,
     },
     intern::{Intern, Interned},
-    reset::{AsyncReset, Reset, SyncReset, ToAsyncReset, ToReset, ToSyncReset},
+    reset::{
+        AsyncReset, Reset, ResetType, ResetTypeDispatch, SyncReset, ToAsyncReset, ToReset,
+        ToSyncReset,
+    },
     ty::{CanonicalType, StaticType, Type},
     util::ConstUsize,
 };
@@ -262,7 +265,7 @@ impl Neg {
         };
         let result_ty = retval.ty();
         retval.literal_bits = arg.to_literal_bits().map(|bits| {
-            Intern::intern_owned(result_ty.bits_from_bigint_wrapping(-SInt::bits_to_bigint(&bits)))
+            Intern::intern_owned(result_ty.bits_from_bigint_wrapping(&-SInt::bits_to_bigint(&bits)))
         });
         retval
     }
@@ -369,7 +372,7 @@ fn binary_op_literal_bits<ResultTy: BoolOrIntType, Lhs: BoolOrIntType, Rhs: Bool
     let rhs = Rhs::bits_to_bigint(&rhs);
     let result = f(lhs, rhs)?;
     Ok(Intern::intern_owned(
-        result_ty.bits_from_bigint_wrapping(result),
+        result_ty.bits_from_bigint_wrapping(&result),
     ))
 }
 
@@ -1344,7 +1347,7 @@ macro_rules! binary_op_fixed_shift {
                     literal_bits: Err(NotALiteralExpr),
                 };
                 retval.literal_bits = lhs.to_literal_bits().map(|bits| {
-                    Intern::intern_owned(retval.ty().bits_from_bigint_wrapping($Trait::$method(
+                    Intern::intern_owned(retval.ty().bits_from_bigint_wrapping(&$Trait::$method(
                         $ty::bits_to_bigint(&bits),
                         rhs,
                     )))
@@ -1621,7 +1624,7 @@ macro_rules! impl_cast_int_op {
                     ty,
                     literal_bits: arg.to_literal_bits().map(|bits| {
                         Intern::intern_owned(
-                            ty.bits_from_bigint_wrapping($from::bits_to_bigint(&bits)),
+                            ty.bits_from_bigint_wrapping(&$from::bits_to_bigint(&bits)),
                         )
                     }),
                 }
@@ -1773,11 +1776,11 @@ impl_cast_bit_op!(CastSIntToAsyncReset, SInt<1>, #[dyn] SInt, AsyncReset, #[trai
 impl_cast_bit_op!(CastSyncResetToBool, SyncReset, Bool);
 impl_cast_bit_op!(CastSyncResetToUInt, SyncReset, UInt<1>, #[dyn] UInt);
 impl_cast_bit_op!(CastSyncResetToSInt, SyncReset, SInt<1>, #[dyn] SInt);
-impl_cast_bit_op!(CastSyncResetToReset, SyncReset, Reset, #[trait] ToReset::to_reset);
+impl_cast_bit_op!(CastSyncResetToReset, SyncReset, Reset);
 impl_cast_bit_op!(CastAsyncResetToBool, AsyncReset, Bool);
 impl_cast_bit_op!(CastAsyncResetToUInt, AsyncReset, UInt<1>, #[dyn] UInt);
 impl_cast_bit_op!(CastAsyncResetToSInt, AsyncReset, SInt<1>, #[dyn] SInt);
-impl_cast_bit_op!(CastAsyncResetToReset, AsyncReset, Reset, #[trait] ToReset::to_reset);
+impl_cast_bit_op!(CastAsyncResetToReset, AsyncReset, Reset);
 impl_cast_bit_op!(CastResetToBool, Reset, Bool);
 impl_cast_bit_op!(CastResetToUInt, Reset, UInt<1>, #[dyn] UInt);
 impl_cast_bit_op!(CastResetToSInt, Reset, SInt<1>, #[dyn] SInt);
@@ -1788,6 +1791,107 @@ impl_cast_bit_op!(CastClockToBool, Clock, Bool);
 impl_cast_bit_op!(CastClockToUInt, Clock, UInt<1>, #[dyn] UInt);
 impl_cast_bit_op!(CastClockToSInt, Clock, SInt<1>, #[dyn] SInt);
 
+impl<T: ResetType> ToReset for Expr<T> {
+    fn to_reset(&self) -> Expr<Reset> {
+        struct Dispatch;
+        impl ResetTypeDispatch for Dispatch {
+            type Input<T: ResetType> = Expr<T>;
+            type Output<T: ResetType> = Expr<Reset>;
+
+            fn reset(self, input: Self::Input<Reset>) -> Self::Output<Reset> {
+                input
+            }
+
+            fn sync_reset(self, input: Self::Input<SyncReset>) -> Self::Output<SyncReset> {
+                input.cast_to_static()
+            }
+
+            fn async_reset(self, input: Self::Input<AsyncReset>) -> Self::Output<AsyncReset> {
+                input.cast_to_static()
+            }
+        }
+        T::dispatch(*self, Dispatch)
+    }
+}
+
+impl ExprCastTo<AsyncReset> for AsyncReset {
+    fn cast_to(src: Expr<Self>, _to_type: AsyncReset) -> Expr<AsyncReset> {
+        src
+    }
+}
+
+impl ExprCastTo<SyncReset> for AsyncReset {
+    fn cast_to(src: Expr<Self>, to_type: SyncReset) -> Expr<SyncReset> {
+        src.cast_to(Bool).cast_to(to_type)
+    }
+}
+
+impl ExprCastTo<Clock> for AsyncReset {
+    fn cast_to(src: Expr<Self>, to_type: Clock) -> Expr<Clock> {
+        src.cast_to(Bool).cast_to(to_type)
+    }
+}
+
+impl ExprCastTo<AsyncReset> for SyncReset {
+    fn cast_to(src: Expr<Self>, to_type: AsyncReset) -> Expr<AsyncReset> {
+        src.cast_to(Bool).cast_to(to_type)
+    }
+}
+
+impl ExprCastTo<SyncReset> for SyncReset {
+    fn cast_to(src: Expr<Self>, _to_type: SyncReset) -> Expr<SyncReset> {
+        src
+    }
+}
+
+impl ExprCastTo<Clock> for SyncReset {
+    fn cast_to(src: Expr<Self>, to_type: Clock) -> Expr<Clock> {
+        src.cast_to(Bool).cast_to(to_type)
+    }
+}
+
+impl ExprCastTo<AsyncReset> for Reset {
+    fn cast_to(src: Expr<Self>, to_type: AsyncReset) -> Expr<AsyncReset> {
+        src.cast_to(Bool).cast_to(to_type)
+    }
+}
+
+impl ExprCastTo<SyncReset> for Reset {
+    fn cast_to(src: Expr<Self>, to_type: SyncReset) -> Expr<SyncReset> {
+        src.cast_to(Bool).cast_to(to_type)
+    }
+}
+
+impl ExprCastTo<Reset> for Reset {
+    fn cast_to(src: Expr<Self>, _to_type: Reset) -> Expr<Reset> {
+        src
+    }
+}
+
+impl ExprCastTo<Clock> for Reset {
+    fn cast_to(src: Expr<Self>, to_type: Clock) -> Expr<Clock> {
+        src.cast_to(Bool).cast_to(to_type)
+    }
+}
+
+impl ExprCastTo<AsyncReset> for Clock {
+    fn cast_to(src: Expr<Self>, to_type: AsyncReset) -> Expr<AsyncReset> {
+        src.cast_to(Bool).cast_to(to_type)
+    }
+}
+
+impl ExprCastTo<SyncReset> for Clock {
+    fn cast_to(src: Expr<Self>, to_type: SyncReset) -> Expr<SyncReset> {
+        src.cast_to(Bool).cast_to(to_type)
+    }
+}
+
+impl ExprCastTo<Clock> for Clock {
+    fn cast_to(src: Expr<Self>, _to_type: Clock) -> Expr<Clock> {
+        src
+    }
+}
+
 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct FieldAccess<FieldType: Type = CanonicalType> {
     base: Expr<Bundle>,

crates/fayalite/src/expr/target.rs

@@ -3,18 +3,19 @@
 use crate::{
     array::Array,
     bundle::{Bundle, BundleField},
-    expr::Flow,
+    expr::{Expr, Flow, ToExpr},
     intern::{Intern, Interned},
     memory::{DynPortType, MemPort},
     module::{Instance, ModuleIO, TargetName},
     reg::Reg,
+    reset::{AsyncReset, Reset, ResetType, ResetTypeDispatch, SyncReset},
     source_location::SourceLocation,
     ty::{CanonicalType, Type},
     wire::Wire,
 };
 use std::fmt;
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct TargetPathBundleField {
     pub name: Interned<str>,
 }
@@ -25,7 +26,7 @@ impl fmt::Display for TargetPathBundleField {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct TargetPathArrayElement {
     pub index: usize,
 }
@@ -36,7 +37,7 @@ impl fmt::Display for TargetPathArrayElement {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub struct TargetPathDynArrayElement {}
 
 impl fmt::Display for TargetPathDynArrayElement {
@@ -45,7 +46,7 @@ impl fmt::Display for TargetPathDynArrayElement {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
 pub enum TargetPathElement {
     BundleField(TargetPathBundleField),
     ArrayElement(TargetPathArrayElement),
@@ -127,6 +128,7 @@ macro_rules! impl_target_base {
         $(#[$enum_meta:meta])*
         $enum_vis:vis enum $TargetBase:ident {
             $(
+                $(#[from = $from:ident])?
                 #[is = $is_fn:ident]
                 #[to = $to_fn:ident]
                 $(#[$variant_meta:meta])*
@@ -150,19 +152,19 @@ macro_rules! impl_target_base {
             }
         }
 
-        $(
+        $($(
         impl From<$VariantTy> for $TargetBase {
-            fn from(value: $VariantTy) -> Self {
+            fn $from(value: $VariantTy) -> Self {
                 Self::$Variant(value)
             }
         }
 
         impl From<$VariantTy> for Target {
-            fn from(value: $VariantTy) -> Self {
+            fn $from(value: $VariantTy) -> Self {
                 $TargetBase::$Variant(value).into()
             }
         }
-        )*
+        )*)?
 
         impl $TargetBase {
             $(
@@ -193,30 +195,79 @@ macro_rules! impl_target_base {
                 }
             }
         }
+
+        impl ToExpr for $TargetBase {
+            type Type = CanonicalType;
+
+            fn to_expr(&self) -> Expr<Self::Type> {
+                match self {
+                    $(Self::$Variant(v) => Expr::canonical(v.to_expr()),)*
+                }
+            }
+        }
     };
 }
 
 impl_target_base! {
-    #[derive(Clone, PartialEq, Eq, Hash)]
+    #[derive(Copy, Clone, PartialEq, Eq, Hash)]
     pub enum TargetBase {
+        #[from = from]
         #[is = is_module_io]
         #[to = module_io]
         ModuleIO(ModuleIO<CanonicalType>),
+        #[from = from]
         #[is = is_mem_port]
         #[to = mem_port]
         MemPort(MemPort<DynPortType>),
         #[is = is_reg]
         #[to = reg]
-        Reg(Reg<CanonicalType>),
+        Reg(Reg<CanonicalType, Reset>),
+        #[is = is_reg_sync]
+        #[to = reg_sync]
+        RegSync(Reg<CanonicalType, SyncReset>),
+        #[is = is_reg_async]
+        #[to = reg_async]
+        RegAsync(Reg<CanonicalType, AsyncReset>),
+        #[from = from]
         #[is = is_wire]
         #[to = wire]
         Wire(Wire<CanonicalType>),
+        #[from = from]
         #[is = is_instance]
         #[to = instance]
         Instance(Instance<Bundle>),
     }
 }
 
+impl<R: ResetType> From<Reg<CanonicalType, R>> for TargetBase {
+    fn from(value: Reg<CanonicalType, R>) -> Self {
+        struct Dispatch;
+        impl ResetTypeDispatch for Dispatch {
+            type Input<T: ResetType> = Reg<CanonicalType, T>;
+            type Output<T: ResetType> = TargetBase;
+
+            fn reset(self, input: Self::Input<Reset>) -> Self::Output<Reset> {
+                TargetBase::Reg(input)
+            }
+
+            fn sync_reset(self, input: Self::Input<SyncReset>) -> Self::Output<SyncReset> {
+                TargetBase::RegSync(input)
+            }
+
+            fn async_reset(self, input: Self::Input<AsyncReset>) -> Self::Output<AsyncReset> {
+                TargetBase::RegAsync(input)
+            }
+        }
+        R::dispatch(value, Dispatch)
+    }
+}
+
+impl<R: ResetType> From<Reg<CanonicalType, R>> for Target {
+    fn from(value: Reg<CanonicalType, R>) -> Self {
+        TargetBase::from(value).into()
+    }
+}
+
 impl fmt::Display for TargetBase {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{:?}", self.target_name())
@@ -229,6 +280,8 @@ impl TargetBase {
             TargetBase::ModuleIO(v) => TargetName(v.scoped_name(), None),
             TargetBase::MemPort(v) => TargetName(v.mem_name(), Some(v.port_name())),
             TargetBase::Reg(v) => TargetName(v.scoped_name(), None),
+            TargetBase::RegSync(v) => TargetName(v.scoped_name(), None),
+            TargetBase::RegAsync(v) => TargetName(v.scoped_name(), None),
             TargetBase::Wire(v) => TargetName(v.scoped_name(), None),
             TargetBase::Instance(v) => TargetName(v.scoped_name(), None),
         }
@@ -238,6 +291,8 @@ impl TargetBase {
             TargetBase::ModuleIO(v) => v.ty(),
             TargetBase::MemPort(v) => v.ty().canonical(),
             TargetBase::Reg(v) => v.ty(),
+            TargetBase::RegSync(v) => v.ty(),
+            TargetBase::RegAsync(v) => v.ty(),
             TargetBase::Wire(v) => v.ty(),
             TargetBase::Instance(v) => v.ty().canonical(),
         }
@@ -313,7 +368,7 @@ impl TargetChild {
     }
 }
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub enum Target {
     Base(Interned<TargetBase>),
     Child(TargetChild),

crates/fayalite/src/firrtl.rs

@@ -31,7 +31,7 @@ use crate::{
         StmtConnect, StmtDeclaration, StmtFormal, StmtIf, StmtInstance, StmtMatch, StmtReg,
         StmtWire,
     },
-    reset::{AsyncReset, Reset, SyncReset},
+    reset::{AsyncReset, Reset, ResetType, SyncReset},
     source_location::SourceLocation,
     ty::{CanonicalType, Type},
     util::{
@@ -1739,6 +1739,14 @@ impl<'a> Exporter<'a> {
                 assert!(!const_ty, "not a constant");
                 self.module.ns.get(expr.scoped_name().1).to_string()
             }
+            ExprEnum::RegSync(expr) => {
+                assert!(!const_ty, "not a constant");
+                self.module.ns.get(expr.scoped_name().1).to_string()
+            }
+            ExprEnum::RegAsync(expr) => {
+                assert!(!const_ty, "not a constant");
+                self.module.ns.get(expr.scoped_name().1).to_string()
+            }
             ExprEnum::MemPort(expr) => {
                 assert!(!const_ty, "not a constant");
                 let mem_name = self.module.ns.get(expr.mem_name().1);
@@ -1848,6 +1856,8 @@ impl<'a> Exporter<'a> {
                         self.module.ns.get(v.mem_name().1)
                     }
                     TargetBase::Reg(v) => self.module.ns.get(v.name_id()),
+                    TargetBase::RegSync(v) => self.module.ns.get(v.name_id()),
+                    TargetBase::RegAsync(v) => self.module.ns.get(v.name_id()),
                     TargetBase::Wire(v) => self.module.ns.get(v.name_id()),
                     TargetBase::Instance(v) => self.module.ns.get(v.name_id()),
                 };
@@ -1956,6 +1966,37 @@ impl<'a> Exporter<'a> {
         drop(memory_indent);
         Ok(body)
     }
+    fn stmt_reg<R: ResetType>(
+        &mut self,
+        stmt_reg: StmtReg<R>,
+        module_name: Ident,
+        definitions: &RcDefinitions,
+        body: &mut String,
+    ) {
+        let StmtReg { annotations, reg } = stmt_reg;
+        let indent = self.indent;
+        self.targeted_annotations(module_name, vec![], &annotations);
+        let name = self.module.ns.get(reg.name_id());
+        let ty = self.type_state.ty(reg.ty());
+        let clk = self.expr(Expr::canonical(reg.clock_domain().clk), definitions, false);
+        if let Some(init) = reg.init() {
+            let rst = self.expr(Expr::canonical(reg.clock_domain().rst), definitions, false);
+            let init = self.expr(init, definitions, false);
+            writeln!(
+                body,
+                "{indent}regreset {name}: {ty}, {clk}, {rst}, {init}{}",
+                FileInfo::new(reg.source_location()),
+            )
+            .unwrap();
+        } else {
+            writeln!(
+                body,
+                "{indent}reg {name}: {ty}, {clk}{}",
+                FileInfo::new(reg.source_location()),
+            )
+            .unwrap();
+        }
+    }
     fn block(
         &mut self,
         module: Interned<Module<Bundle>>,
@@ -2126,30 +2167,14 @@ impl<'a> Exporter<'a> {
                     )
                     .unwrap();
                 }
-                Stmt::Declaration(StmtDeclaration::Reg(StmtReg { annotations, reg })) => {
+                Stmt::Declaration(StmtDeclaration::Reg(stmt_reg)) => {
-                    self.targeted_annotations(module_name, vec![], &annotations);
+                    self.stmt_reg(stmt_reg, module_name, &definitions, &mut body);
-                    let name = self.module.ns.get(reg.name_id());
-                    let ty = self.type_state.ty(reg.ty());
-                    let clk =
-                        self.expr(Expr::canonical(reg.clock_domain().clk), &definitions, false);
-                    if let Some(init) = reg.init() {
-                        let rst =
-                            self.expr(Expr::canonical(reg.clock_domain().rst), &definitions, false);
-                        let init = self.expr(init, &definitions, false);
-                        writeln!(
-                            body,
-                            "{indent}regreset {name}: {ty}, {clk}, {rst}, {init}{}",
-                            FileInfo::new(reg.source_location()),
-                        )
-                        .unwrap();
-                    } else {
-                        writeln!(
-                            body,
-                            "{indent}reg {name}: {ty}, {clk}{}",
-                            FileInfo::new(reg.source_location()),
-                        )
-                        .unwrap();
                 }
+                Stmt::Declaration(StmtDeclaration::RegSync(stmt_reg)) => {
+                    self.stmt_reg(stmt_reg, module_name, &definitions, &mut body);
+                }
+                Stmt::Declaration(StmtDeclaration::RegAsync(stmt_reg)) => {
+                    self.stmt_reg(stmt_reg, module_name, &definitions, &mut body);
                 }
                 Stmt::Declaration(StmtDeclaration::Instance(StmtInstance {
                     annotations,

crates/fayalite/src/int.rs

@@ -202,17 +202,17 @@ macro_rules! impl_int {
                     bit_width: self.width(),
                 }
             }
-            pub fn bits_from_bigint_wrapping(self, v: BigInt) -> BitVec {
+            pub fn bits_from_bigint_wrapping(self, v: &BigInt) -> BitVec {
                 BoolOrIntType::bits_from_bigint_wrapping(self, v)
             }
-            pub fn from_bigint_wrapping(self, v: BigInt) -> $value<Width> {
+            pub fn from_bigint_wrapping(self, v: &BigInt) -> $value<Width> {
                 $value {
                     bits: Arc::new(self.bits_from_bigint_wrapping(v)),
                     _phantom: PhantomData,
                 }
             }
             pub fn from_int_wrapping(self, v: impl Into<BigInt>) -> $value<Width> {
-                self.from_bigint_wrapping(v.into())
+                self.from_bigint_wrapping(&v.into())
             }
             pub fn zero(self) -> $value<Width> {
                 self.from_int_wrapping(0u8)
@@ -227,12 +227,29 @@ macro_rules! impl_int {
         impl<Width: Size> BoolOrIntType for $name<Width> {
             type Width = Width;
             type Signed = ConstBool<$SIGNED>;
+            type Value = $value<Width>;
             fn width(self) -> usize {
                 $name::width(self)
             }
             fn new(width: Width::SizeType) -> Self {
                 $name { width }
             }
+            fn value_from_bigint_wrapping(self, v: &BigInt) -> Self::Value {
+                $value::<Width>::from_bigint_wrapping(self, v)
+            }
+            fn bits_to_value(bits: Cow<'_, BitSlice>) -> Self::Value {
+                #[derive(Copy, Clone, Eq, PartialEq, Hash)]
+                struct MemoizeBitsToValue;
+                impl Memoize for MemoizeBitsToValue {
+                    type Input = BitSlice;
+                    type InputOwned = BitVec;
+                    type Output = Arc<BitVec>;
+                    fn inner(self, input: &Self::Input) -> Self::Output {
+                        Arc::new(input.to_bitvec())
+                    }
+                }
+                $value::new(MemoizeBitsToValue.get_cow(bits))
+            }
             fn bits_to_expr(bits: Cow<'_, BitSlice>) -> Expr<Self> {
                 #[derive(Copy, Clone, Eq, PartialEq, Hash)]
                 struct MemoizeBitsToExpr;
@@ -334,6 +351,24 @@ macro_rules! impl_int {
             }
         }
 
+        impl<Width: Size> PartialOrd for $value<Width> {
+            fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+                Some(self.cmp(other))
+            }
+        }
+
+        impl<Width: Size> Ord for $value<Width> {
+            fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+                self.to_bigint().cmp(&other.to_bigint())
+            }
+        }
+
+        impl<Width: Size> From<$value<Width>> for BigInt {
+            fn from(v: $value<Width>) -> BigInt {
+                v.to_bigint()
+            }
+        }
+
         impl<Width: Size> $value<Width> {
             pub fn width(&self) -> usize {
                 if let Some(retval) = Width::KNOWN_VALUE {
@@ -343,7 +378,7 @@ macro_rules! impl_int {
                     self.bits.len()
                 }
             }
-            pub fn from_bigint_wrapping(ty: $name<Width>, v: BigInt) -> $value<Width> {
+            pub fn from_bigint_wrapping(ty: $name<Width>, v: &BigInt) -> $value<Width> {
                 ty.from_bigint_wrapping(v)
             }
             pub fn to_bigint(&self) -> BigInt {
@@ -485,6 +520,19 @@ macro_rules! impl_prim_int {
         $(#[$meta:meta])*
         $prim_int:ident, $ty:ty
     ) => {
+        impl From<$prim_int> for <$ty as BoolOrIntType>::Value {
+            fn from(v: $prim_int) -> Self {
+                <$ty>::le_bytes_to_value_wrapping(
+                    &v.to_le_bytes(),
+                    <$ty as BoolOrIntType>::Width::VALUE,
+                )
+            }
+        }
+        impl From<NonZero<$prim_int>> for <$ty as BoolOrIntType>::Value {
+            fn from(v: NonZero<$prim_int>) -> Self {
+                v.get().into()
+            }
+        }
         $(#[$meta])*
         impl ToExpr for $prim_int {
             type Type = $ty;
@@ -501,10 +549,7 @@ macro_rules! impl_prim_int {
             type Type = $ty;
 
             fn to_expr(&self) -> Expr<Self::Type> {
-                <$ty>::le_bytes_to_expr_wrapping(
+                self.get().to_expr()
-                    &self.get().to_le_bytes(),
-                    <$ty as BoolOrIntType>::Width::VALUE,
-                )
             }
         }
     };
@@ -522,18 +567,27 @@ impl_prim_int!(i64, SInt<64>);
 impl_prim_int!(i128, SInt<128>);
 
 impl_prim_int!(
-    /// for portability reasons, [`usize`] always translates to [`UInt<64>`]
+    /// for portability reasons, [`usize`] always translates to [`UInt<64>`][type@UInt]
     usize, UInt<64>
 );
 
 impl_prim_int!(
-    /// for portability reasons, [`isize`] always translates to [`SInt<64>`]
+    /// for portability reasons, [`isize`] always translates to [`SInt<64>`][type@SInt]
     isize, SInt<64>
 );
 
 pub trait BoolOrIntType: Type + sealed::BoolOrIntTypeSealed {
     type Width: Size;
     type Signed: GenericConstBool;
+    type Value: Clone
+        + Ord
+        + std::hash::Hash
+        + fmt::Debug
+        + Send
+        + Sync
+        + 'static
+        + ToExpr<Type = Self>
+        + Into<BigInt>;
     fn width(self) -> usize;
     fn new(width: <Self::Width as Size>::SizeType) -> Self;
     fn new_static() -> Self
@@ -548,17 +602,24 @@ pub trait BoolOrIntType: Type + sealed::BoolOrIntTypeSealed {
     fn as_same_width_uint(self) -> UIntType<Self::Width> {
         UIntType::new(Self::Width::from_usize(self.width()))
     }
-    fn bits_from_bigint_wrapping(self, v: BigInt) -> BitVec {
+    fn value_from_int_wrapping(self, v: impl Into<BigInt>) -> Self::Value {
-        let width = self.width();
+        self.value_from_bigint_wrapping(&v.into())
+    }
+    fn value_from_bigint_wrapping(self, v: &BigInt) -> Self::Value;
+    fn bits_from_bigint_wrapping(self, v: &BigInt) -> BitVec {
+        let mut bits = BitVec::repeat(false, self.width());
+        Self::copy_bits_from_bigint_wrapping(v, &mut bits);
+        bits
+    }
+    fn copy_bits_from_bigint_wrapping(v: &BigInt, bits: &mut BitSlice) {
+        let width = bits.len();
         let mut bytes = v.to_signed_bytes_le();
         bytes.resize(
             width.div_ceil(u8::BITS as usize),
             if v.is_negative() { 0xFF } else { 0 },
         );
         let bitslice = &BitSlice::<u8, Lsb0>::from_slice(&bytes)[..width];
-        let mut bits = BitVec::new();
+        bits.clone_from_bitslice(bitslice);
-        bits.extend_from_bitslice(bitslice);
-        bits
     }
     fn bits_to_bigint(bits: &BitSlice) -> BigInt {
         let sign_byte = if Self::Signed::VALUE && bits.last().as_deref().copied().unwrap_or(false) {
@@ -570,8 +631,9 @@ pub trait BoolOrIntType: Type + sealed::BoolOrIntTypeSealed {
         BitSlice::<u8, Lsb0>::from_slice_mut(&mut bytes)[..bits.len()].clone_from_bitslice(bits);
         BigInt::from_signed_bytes_le(&bytes)
     }
+    fn bits_to_value(bits: Cow<'_, BitSlice>) -> Self::Value;
     fn bits_to_expr(bits: Cow<'_, BitSlice>) -> Expr<Self>;
-    fn le_bytes_to_expr_wrapping(bytes: &[u8], bit_width: usize) -> Expr<Self> {
+    fn le_bytes_to_bits_wrapping(bytes: &[u8], bit_width: usize) -> BitVec {
         let bitslice = BitSlice::<u8, Lsb0>::from_slice(bytes);
         let bitslice = &bitslice[..bit_width.min(bitslice.len())];
         let mut bits = BitVec::new();
@@ -580,7 +642,17 @@ pub trait BoolOrIntType: Type + sealed::BoolOrIntTypeSealed {
             bit_width,
             Self::Signed::VALUE && bits.last().as_deref().copied().unwrap_or(false),
         );
-        Self::bits_to_expr(Cow::Owned(bits))
+        bits
+    }
+    fn le_bytes_to_expr_wrapping(bytes: &[u8], bit_width: usize) -> Expr<Self> {
+        Self::bits_to_expr(Cow::Owned(Self::le_bytes_to_bits_wrapping(
+            bytes, bit_width,
+        )))
+    }
+    fn le_bytes_to_value_wrapping(bytes: &[u8], bit_width: usize) -> Self::Value {
+        Self::bits_to_value(Cow::Owned(Self::le_bytes_to_bits_wrapping(
+            bytes, bit_width,
+        )))
     }
 }
 
@@ -632,6 +704,7 @@ impl sealed::BoolOrIntTypeSealed for Bool {}
 impl BoolOrIntType for Bool {
     type Width = ConstUsize<1>;
     type Signed = ConstBool<false>;
+    type Value = bool;
 
     fn width(self) -> usize {
         1
@@ -642,10 +715,19 @@ impl BoolOrIntType for Bool {
         Bool
     }
 
+    fn value_from_bigint_wrapping(self, v: &BigInt) -> Self::Value {
+        v.bit(0)
+    }
+
     fn bits_to_expr(bits: Cow<'_, BitSlice>) -> Expr<Self> {
         assert_eq!(bits.len(), 1);
         bits[0].to_expr()
     }
+
+    fn bits_to_value(bits: Cow<'_, BitSlice>) -> Self::Value {
+        assert_eq!(bits.len(), 1);
+        bits[0]
+    }
 }
 
 impl Bool {

crates/fayalite/src/lib.rs

@@ -11,6 +11,59 @@ extern crate self as fayalite;
 #[doc(hidden)]
 pub use std as __std;
 
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __cfg_expansion_helper {
+    (
+        [
+            $($evaluated_cfgs:ident($($evaluated_exprs:tt)*) = $evaluated_results:ident,)*
+        ]
+        [
+            $cfg:ident($($expr:tt)*),
+            $($unevaluated_cfgs:ident($($unevaluated_exprs:tt)*),)*
+        ]
+        // pass as tt so we get right span for attribute
+        $after_evaluation_attr:tt $after_evaluation_body:tt
+    ) => {
+        #[$cfg($($expr)*)]
+        $crate::__cfg_expansion_helper! {
+            [
+                $($evaluated_cfgs($($evaluated_exprs)*) = $evaluated_results,)*
+                $cfg($($expr)*) = true,
+            ]
+            [
+                $($unevaluated_cfgs($($unevaluated_exprs)*),)*
+            ]
+            $after_evaluation_attr $after_evaluation_body
+        }
+        #[$cfg(not($($expr)*))]
+        $crate::__cfg_expansion_helper! {
+            [
+                $($evaluated_cfgs($($evaluated_exprs)*) = $evaluated_results,)*
+                $cfg($($expr)*) = false,
+            ]
+            [
+                $($unevaluated_cfgs($($unevaluated_exprs)*),)*
+            ]
+            $after_evaluation_attr $after_evaluation_body
+        }
+    };
+    (
+        [
+            $($evaluated_cfgs:ident($($evaluated_exprs:tt)*) = $evaluated_results:ident,)*
+        ]
+        []
+        // don't use #[...] so we get right span for `#` and `[]` of attribute
+        {$($after_evaluation_attr:tt)*} {$($after_evaluation_body:tt)*}
+    ) => {
+        $($after_evaluation_attr)*
+        #[__evaluated_cfgs([
+            $($evaluated_cfgs($($evaluated_exprs)*) = $evaluated_results,)*
+        ])]
+        $($after_evaluation_body)*
+    };
+}
+
 #[doc(inline)]
 /// The `#[hdl_module]` attribute is applied to a Rust function so that that function creates
 /// a [`Module`][`::fayalite::module::Module`] when called.
@@ -46,6 +99,7 @@ pub mod module;
 pub mod prelude;
 pub mod reg;
 pub mod reset;
+pub mod sim;
 pub mod source_location;
 pub mod testing;
 pub mod ty;

crates/fayalite/src/memory.rs

@@ -22,7 +22,7 @@ use std::{
     fmt,
     hash::{Hash, Hasher},
     marker::PhantomData,
-    num::NonZeroU32,
+    num::NonZeroUsize,
     rc::Rc,
 };
 
@@ -478,7 +478,7 @@ struct MemImpl<Element: Type, Len: Size, P> {
     initial_value: Option<Interned<BitSlice>>,
     ports: P,
     read_latency: usize,
-    write_latency: NonZeroU32,
+    write_latency: NonZeroUsize,
     read_under_write: ReadUnderWrite,
     port_annotations: Interned<[TargetedAnnotation]>,
     mem_annotations: Interned<[Annotation]>,
@@ -519,7 +519,12 @@ impl<Element: Type, Len: Size> fmt::Debug for Mem<Element, Len> {
         f.debug_struct("Mem")
             .field("name", scoped_name)
             .field("array_type", array_type)
-            .field("initial_value", initial_value)
+            .field(
+                "initial_value",
+                &initial_value.as_ref().map(|initial_value| {
+                    DebugMemoryData::from_bit_slice(*array_type, initial_value)
+                }),
+            )
             .field("read_latency", read_latency)
             .field("write_latency", write_latency)
             .field("read_under_write", read_under_write)
@@ -562,7 +567,7 @@ impl<Element: Type, Len: Size> Mem<Element, Len> {
         initial_value: Option<Interned<BitSlice>>,
         ports: Interned<[MemPort<DynPortType>]>,
         read_latency: usize,
-        write_latency: NonZeroU32,
+        write_latency: NonZeroUsize,
         read_under_write: ReadUnderWrite,
         port_annotations: Interned<[TargetedAnnotation]>,
         mem_annotations: Interned<[Annotation]>,
@@ -645,7 +650,7 @@ impl<Element: Type, Len: Size> Mem<Element, Len> {
     pub fn read_latency(self) -> usize {
         self.0.read_latency
     }
-    pub fn write_latency(self) -> NonZeroU32 {
+    pub fn write_latency(self) -> NonZeroUsize {
         self.0.write_latency
     }
     pub fn read_under_write(self) -> ReadUnderWrite {
@@ -707,7 +712,7 @@ pub(crate) struct MemBuilderTarget {
     pub(crate) initial_value: Option<Interned<BitSlice>>,
     pub(crate) ports: Vec<MemPort<DynPortType>>,
     pub(crate) read_latency: usize,
-    pub(crate) write_latency: NonZeroU32,
+    pub(crate) write_latency: NonZeroUsize,
     pub(crate) read_under_write: ReadUnderWrite,
     pub(crate) port_annotations: Vec<TargetedAnnotation>,
     pub(crate) mem_annotations: Vec<Annotation>,
@@ -867,7 +872,7 @@ impl<Element: Type, Len: Size> MemBuilder<Element, Len> {
             initial_value: None,
             ports: vec![],
             read_latency: 0,
-            write_latency: NonZeroU32::new(1).unwrap(),
+            write_latency: NonZeroUsize::new(1).unwrap(),
             read_under_write: ReadUnderWrite::Old,
             port_annotations: vec![],
             mem_annotations: vec![],
@@ -1030,10 +1035,10 @@ impl<Element: Type, Len: Size> MemBuilder<Element, Len> {
     pub fn read_latency(&mut self, read_latency: usize) {
         self.target.borrow_mut().read_latency = read_latency;
     }
-    pub fn get_write_latency(&self) -> NonZeroU32 {
+    pub fn get_write_latency(&self) -> NonZeroUsize {
         self.target.borrow().write_latency
     }
-    pub fn write_latency(&mut self, write_latency: NonZeroU32) {
+    pub fn write_latency(&mut self, write_latency: NonZeroUsize) {
         self.target.borrow_mut().write_latency = write_latency;
     }
     pub fn get_read_under_write(&self) -> ReadUnderWrite {
@@ -1079,3 +1084,61 @@ pub fn splat_mask<T: Type>(ty: T, value: Expr<Bool>) -> Expr<AsMask<T>> {
         )),
     }
 }
+
+pub trait DebugMemoryDataGetElement {
+    fn get_element(&self, element_index: usize, array_type: Array) -> &BitSlice;
+}
+
+impl<'a, F: ?Sized + Fn(usize, Array) -> &'a BitSlice> DebugMemoryDataGetElement for &'a F {
+    fn get_element(&self, element_index: usize, array_type: Array) -> &BitSlice {
+        self(element_index, array_type)
+    }
+}
+
+#[derive(Clone)]
+pub struct DebugMemoryData<GetElement: DebugMemoryDataGetElement> {
+    pub array_type: Array,
+    pub get_element: GetElement,
+}
+
+impl DebugMemoryDataGetElement for &'_ BitSlice {
+    fn get_element(&self, element_index: usize, array_type: Array) -> &BitSlice {
+        assert!(element_index < array_type.len());
+        let stride = array_type.element().bit_width();
+        let start = element_index
+            .checked_mul(stride)
+            .expect("memory is too big");
+        let end = start.checked_add(stride).expect("memory is too big");
+        &self[start..end]
+    }
+}
+
+impl<'a> DebugMemoryData<&'a BitSlice> {
+    pub fn from_bit_slice<T: Type, Depth: Size>(
+        array_type: ArrayType<T, Depth>,
+        bit_slice: &'a BitSlice,
+    ) -> Self {
+        let array_type = array_type.as_dyn_array();
+        assert_eq!(bit_slice.len(), array_type.type_properties().bit_width);
+        Self {
+            array_type,
+            get_element: bit_slice,
+        }
+    }
+}
+
+impl<GetElement: DebugMemoryDataGetElement> fmt::Debug for DebugMemoryData<GetElement> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if self.array_type.len() == 0 {
+            return f.write_str("[]");
+        }
+        writeln!(f, "[\n    // len = {:#x}", self.array_type.len())?;
+        for element_index in 0..self.array_type.len() {
+            let element = crate::util::BitSliceWriteWithBase(
+                self.get_element.get_element(element_index, self.array_type),
+            );
+            writeln!(f, "    [{element_index:#x}]: {element:#x},")?;
+        }
+        f.write_str("]")
+    }
+}

crates/fayalite/src/module.rs

@@ -20,6 +20,7 @@ use crate::{
     intern::{Intern, Interned},
     memory::{Mem, MemBuilder, MemBuilderTarget, PortName},
     reg::Reg,
+    reset::{AsyncReset, Reset, ResetType, ResetTypeDispatch, SyncReset},
     source_location::SourceLocation,
     ty::{CanonicalType, Type},
     util::ScopedRef,
@@ -180,7 +181,7 @@ impl Block {
     }
 }
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct StmtConnect {
     pub lhs: Expr<CanonicalType>,
     pub rhs: Expr<CanonicalType>,
@@ -235,7 +236,7 @@ impl fmt::Debug for StmtConnect {
     }
 }
 
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Copy, Clone, PartialEq, Eq, Hash)]
 pub struct StmtFormal {
     pub kind: FormalKind,
     pub clk: Expr<Clock>,
@@ -284,6 +285,8 @@ pub struct StmtIf<S: ModuleBuildingStatus = ModuleBuilt> {
     pub blocks: [S::Block; 2],
 }
 
+impl Copy for StmtIf {}
+
 impl<S: ModuleBuildingStatus> StmtIf<S> {
     pub fn then_block(&self) -> S::Block {
         self.blocks[0]
@@ -315,6 +318,8 @@ pub struct StmtMatch<S: ModuleBuildingStatus = ModuleBuilt> {
     pub blocks: Interned<[S::Block]>,
 }
 
+impl Copy for StmtMatch {}
+
 impl StmtMatch {
     #[track_caller]
     fn assert_validity(&self) {
@@ -346,7 +351,7 @@ macro_rules! wrapper_enum {
         $(#[$enum_meta:meta])*
         $vis:vis enum $enum_name:ident<$T_enum:ident: $T_bound:ident = $T_enum_default:ident> {
             $(
-                #[is = $is_fn:ident, as_ref = $as_ref_fn:ident]
+                #[is = $is_fn:ident, as_ref = $as_ref_fn:ident $(, from = $from:ident)?]
                 $(#[$variant_meta:meta])*
                 $Variant:ident($VariantTy:ty),
             )*
@@ -358,7 +363,7 @@ macro_rules! wrapper_enum {
             $(#[$enum_meta])*
             $vis enum $enum_name<$T_enum: $T_bound = $T_enum_default> {
                 $(
-                    #[is = $is_fn, as_ref = $as_ref_fn]
+                    #[is = $is_fn, as_ref = $as_ref_fn $(, from = $from)?]
                     $(#[$variant_meta])*
                     $Variant($VariantTy),
                 )*
@@ -385,7 +390,7 @@ macro_rules! wrapper_enum {
         $(#[$enum_meta:meta])*
         $vis:vis enum $enum_name:ident<$T_enum:ident: $T_bound:ident = $T_enum_default:ident> {
             $(
-                #[is = $is_fn:ident, as_ref = $as_ref_fn:ident]
+                #[is = $is_fn:ident, as_ref = $as_ref_fn:ident $(, from = $from:ident)?]
                 $(#[$variant_meta:meta])*
                 $Variant:ident($VariantTy:ty),
             )*
@@ -397,22 +402,22 @@ macro_rules! wrapper_enum {
             $(#[$enum_meta])*
             $vis enum $enum_name<$T_enum: $T_bound = $T_enum_default> {
                 $(
-                    #[is = $is_fn, as_ref = $as_ref_fn]
+                    #[is = $is_fn, as_ref = $as_ref_fn $(, from = $from)?]
                     $(#[$variant_meta])*
                     $Variant($VariantTy),
                 )*
             }
         }
 
-        $(
+        $($(
             wrapper_enum! {
                 impl $T_to From<$VariantTy> for $to_type {
-                    fn from(value: $VariantTy) -> Self {
+                    fn $from(value: $VariantTy) -> Self {
                         $enum_name::$Variant(value).into()
                     }
                 }
             }
-        )*
+        )?)*
     };
     (
         #[impl()]
@@ -420,7 +425,7 @@ macro_rules! wrapper_enum {
         $(#[$enum_meta:meta])*
         $vis:vis enum $enum_name:ident<$T_enum:ident: $T_bound:ident = $T_enum_default:ident> {
             $(
-                #[is = $is_fn:ident, as_ref = $as_ref_fn:ident]
+                #[is = $is_fn:ident, as_ref = $as_ref_fn:ident $(, from = $from:ident)?]
                 $(#[$variant_meta:meta])*
                 $Variant:ident($VariantTy:ty),
             )*
@@ -459,13 +464,15 @@ pub struct StmtWire<S: ModuleBuildingStatus = ModuleBuilt> {
     pub wire: Wire<CanonicalType>,
 }
 
+impl Copy for StmtWire {}
+
 #[derive(Hash, Clone, PartialEq, Eq, Debug)]
-pub struct StmtReg<S: ModuleBuildingStatus = ModuleBuilt> {
+pub struct StmtReg<R: ResetType, S: ModuleBuildingStatus = ModuleBuilt> {
     pub annotations: S::StmtAnnotations,
-    pub reg: Reg<CanonicalType>,
+    pub reg: Reg<CanonicalType, R>,
 }
 
-impl Copy for StmtReg {}
+impl<R: ResetType> Copy for StmtReg<R> {}
 
 #[derive(Clone, PartialEq, Eq, Hash, Debug)]
 pub struct StmtInstance<S: ModuleBuildingStatus = ModuleBuilt> {
@@ -473,6 +480,8 @@ pub struct StmtInstance<S: ModuleBuildingStatus = ModuleBuilt> {
     pub instance: Instance<Bundle>,
 }
 
+impl Copy for StmtInstance {}
+
 wrapper_enum! {
     #[impl(
         (<S: ModuleBuildingStatus>) self: StmtDeclaration<S> = self,
@@ -481,20 +490,57 @@ wrapper_enum! {
     #[to((<S: ModuleBuildingStatus>) StmtDeclaration<S>, (<S: ModuleBuildingStatus>) Stmt<S>)]
     #[derive(Clone, PartialEq, Eq, Hash)]
     pub enum StmtDeclaration<S: ModuleBuildingStatus = ModuleBuilt> {
-        #[is = is_wire, as_ref = wire]
+        #[is = is_wire, as_ref = wire, from = from]
         Wire(StmtWire<S>),
         #[is = is_reg, as_ref = reg]
-        Reg(StmtReg<S>),
+        Reg(StmtReg<Reset, S>),
-        #[is = is_instance, as_ref = instance]
+        #[is = is_reg_sync, as_ref = reg_sync]
+        RegSync(StmtReg<SyncReset, S>),
+        #[is = is_reg_async, as_ref = reg_async]
+        RegAsync(StmtReg<AsyncReset, S>),
+        #[is = is_instance, as_ref = instance, from = from]
         Instance(StmtInstance<S>),
     }
 }
 
+impl Copy for StmtDeclaration {}
+
+impl<S: ModuleBuildingStatus, R: ResetType> From<StmtReg<R, S>> for Stmt<S> {
+    fn from(value: StmtReg<R, S>) -> Self {
+        StmtDeclaration::from(value).into()
+    }
+}
+
+impl<S: ModuleBuildingStatus, R: ResetType> From<StmtReg<R, S>> for StmtDeclaration<S> {
+    fn from(value: StmtReg<R, S>) -> Self {
+        struct Dispatch<S>(PhantomData<S>);
+        impl<S: ModuleBuildingStatus> ResetTypeDispatch for Dispatch<S> {
+            type Input<T: ResetType> = StmtReg<T, S>;
+            type Output<T: ResetType> = StmtDeclaration<S>;
+
+            fn reset(self, input: Self::Input<Reset>) -> Self::Output<Reset> {
+                StmtDeclaration::Reg(input)
+            }
+
+            fn sync_reset(self, input: Self::Input<SyncReset>) -> Self::Output<SyncReset> {
+                StmtDeclaration::RegSync(input)
+            }
+
+            fn async_reset(self, input: Self::Input<AsyncReset>) -> Self::Output<AsyncReset> {
+                StmtDeclaration::RegAsync(input)
+            }
+        }
+        R::dispatch(value, Dispatch(PhantomData))
+    }
+}
+
 impl<S: ModuleBuildingStatus> StmtDeclaration<S> {
     pub fn annotations(&self) -> S::StmtAnnotations {
         match self {
             StmtDeclaration::Wire(v) => v.annotations,
             StmtDeclaration::Reg(v) => v.annotations,
+            StmtDeclaration::RegSync(v) => v.annotations,
+            StmtDeclaration::RegAsync(v) => v.annotations,
             StmtDeclaration::Instance(v) => v.annotations,
         }
     }
@@ -502,6 +548,8 @@ impl<S: ModuleBuildingStatus> StmtDeclaration<S> {
         match self {
             StmtDeclaration::Wire(v) => v.wire.source_location(),
             StmtDeclaration::Reg(v) => v.reg.source_location(),
+            StmtDeclaration::RegSync(v) => v.reg.source_location(),
+            StmtDeclaration::RegAsync(v) => v.reg.source_location(),
             StmtDeclaration::Instance(v) => v.instance.source_location(),
         }
     }
@@ -509,20 +557,26 @@ impl<S: ModuleBuildingStatus> StmtDeclaration<S> {
         match self {
             StmtDeclaration::Wire(v) => v.wire.scoped_name(),
             StmtDeclaration::Reg(v) => v.reg.scoped_name(),
+            StmtDeclaration::RegSync(v) => v.reg.scoped_name(),
+            StmtDeclaration::RegAsync(v) => v.reg.scoped_name(),
             StmtDeclaration::Instance(v) => v.instance.scoped_name(),
         }
     }
     pub fn sub_stmt_blocks(&self) -> &[S::Block] {
         match self {
-            StmtDeclaration::Wire(_) | StmtDeclaration::Reg(_) | StmtDeclaration::Instance(_) => {
+            StmtDeclaration::Wire(_)
-                &[]
+            | StmtDeclaration::Reg(_)
-            }
+            | StmtDeclaration::RegSync(_)
+            | StmtDeclaration::RegAsync(_)
+            | StmtDeclaration::Instance(_) => &[],
         }
     }
     pub fn canonical_ty(&self) -> CanonicalType {
         match self {
             StmtDeclaration::Wire(v) => v.wire.ty(),
             StmtDeclaration::Reg(v) => v.reg.ty(),
+            StmtDeclaration::RegSync(v) => v.reg.ty(),
+            StmtDeclaration::RegAsync(v) => v.reg.ty(),
             StmtDeclaration::Instance(v) => CanonicalType::Bundle(v.instance.ty()),
         }
     }
@@ -533,19 +587,21 @@ wrapper_enum! {
     #[to((<S: ModuleBuildingStatus>) Stmt<S>)]
     #[derive(Clone, PartialEq, Eq, Hash)]
     pub enum Stmt<S: ModuleBuildingStatus = ModuleBuilt> {
-        #[is = is_connect, as_ref = connect]
+        #[is = is_connect, as_ref = connect, from = from]
         Connect(StmtConnect),
-        #[is = is_formal, as_ref = formal]
+        #[is = is_formal, as_ref = formal, from = from]
         Formal(StmtFormal),
-        #[is = is_if, as_ref = if_]
+        #[is = is_if, as_ref = if_, from = from]
         If(StmtIf<S>),
-        #[is = is_match, as_ref = match_]
+        #[is = is_match, as_ref = match_, from = from]
         Match(StmtMatch<S>),
-        #[is = is_declaration, as_ref = declaration]
+        #[is = is_declaration, as_ref = declaration, from = from]
         Declaration(StmtDeclaration<S>),
     }
 }
 
+impl Copy for Stmt {}
+
 impl<S: ModuleBuildingStatus> Stmt<S> {
     pub fn sub_stmt_blocks(&self) -> &[S::Block] {
         match self {
@@ -714,6 +770,18 @@ impl<T: BundleType> Instance<T> {
             source_location,
         }
     }
+    pub fn from_canonical(v: Instance<Bundle>) -> Self {
+        let Instance {
+            scoped_name,
+            instantiated,
+            source_location,
+        } = v;
+        Self {
+            scoped_name,
+            instantiated: Module::from_canonical(*instantiated).intern_sized(),
+            source_location,
+        }
+    }
     pub fn containing_module_name(self) -> Interned<str> {
         self.containing_module_name_id().0
     }
@@ -958,6 +1026,14 @@ impl From<NormalModuleBody<ModuleBuilding>> for NormalModuleBody {
                                 annotations: (),
                                 reg,
                             }) => StmtReg { annotations, reg }.into(),
+                            StmtDeclaration::RegSync(StmtReg {
+                                annotations: (),
+                                reg,
+                            }) => StmtReg { annotations, reg }.into(),
+                            StmtDeclaration::RegAsync(StmtReg {
+                                annotations: (),
+                                reg,
+                            }) => StmtReg { annotations, reg }.into(),
                             StmtDeclaration::Instance(StmtInstance {
                                 annotations: (),
                                 instance,
@@ -1661,6 +1737,14 @@ impl AssertValidityState {
                     annotations: _,
                     reg,
                 })) => self.insert_new_base(TargetBase::intern_sized(reg.into()), block),
+                Stmt::Declaration(StmtDeclaration::RegSync(StmtReg {
+                    annotations: _,
+                    reg,
+                })) => self.insert_new_base(TargetBase::intern_sized(reg.into()), block),
+                Stmt::Declaration(StmtDeclaration::RegAsync(StmtReg {
+                    annotations: _,
+                    reg,
+                })) => self.insert_new_base(TargetBase::intern_sized(reg.into()), block),
                 Stmt::Declaration(StmtDeclaration::Instance(StmtInstance {
                     annotations: _,
                     instance,
@@ -1842,10 +1926,10 @@ impl<CD> RegBuilder<CD, (), ()> {
 }
 
 impl<I, T: Type> RegBuilder<(), I, T> {
-    pub fn clock_domain(
+    pub fn clock_domain<R: ResetType>(
         self,
-        clock_domain: impl ToExpr<Type = ClockDomain>,
+        clock_domain: impl ToExpr<Type = ClockDomain<R>>,
-    ) -> RegBuilder<Expr<ClockDomain>, I, T> {
+    ) -> RegBuilder<Expr<ClockDomain<R>>, I, T> {
         let Self {
             name,
             source_location,
@@ -1863,7 +1947,7 @@ impl<I, T: Type> RegBuilder<(), I, T> {
     }
 }
 
-impl<T: Type> RegBuilder<Expr<ClockDomain>, Option<Expr<T>>, T> {
+impl<T: Type, R: ResetType> RegBuilder<Expr<ClockDomain<R>>, Option<Expr<T>>, T> {
     #[track_caller]
     pub fn build(self) -> Expr<T> {
         let Self {
@@ -2188,6 +2272,16 @@ pub fn annotate<T: Type>(target: Expr<T>, annotations: impl IntoAnnotations) {
             reg,
         }
         .into(),
+        TargetBase::RegSync(reg) => StmtReg {
+            annotations: (),
+            reg,
+        }
+        .into(),
+        TargetBase::RegAsync(reg) => StmtReg {
+            annotations: (),
+            reg,
+        }
+        .into(),
         TargetBase::Wire(wire) => StmtWire {
             annotations: (),
             wire,
@@ -2629,3 +2723,50 @@ impl<T: Type> ModuleIO<T> {
         self.ty
     }
 }
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy)]
+pub enum InstantiatedModule {
+    Base(Interned<Module<Bundle>>),
+    Child {
+        parent: Interned<InstantiatedModule>,
+        instance: Interned<Instance<Bundle>>,
+    },
+}
+
+impl InstantiatedModule {
+    pub fn leaf_module(self) -> Interned<Module<Bundle>> {
+        match self {
+            InstantiatedModule::Base(base) => base,
+            InstantiatedModule::Child { instance, .. } => instance.instantiated(),
+        }
+    }
+    fn write_path(self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            InstantiatedModule::Base(base) => fmt::Debug::fmt(&base.name_id(), f),
+            InstantiatedModule::Child { parent, instance } => {
+                parent.write_path(f)?;
+                write!(f, ".{}", instance.name_id())
+            }
+        }
+    }
+}
+
+impl fmt::Debug for InstantiatedModule {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "InstantiatedModule(")?;
+        self.write_path(f)?;
+        write!(f, ": {})", self.leaf_module().name_id())
+    }
+}
+
+#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy)]
+pub struct TargetInInstantiatedModule {
+    pub instantiated_module: InstantiatedModule,
+    pub target: Target,
+}
+
+#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy)]
+pub struct ExprInInstantiatedModule<T: Type> {
+    pub instantiated_module: InstantiatedModule,
+    pub expr: Expr<T>,
+}

crates/fayalite/src/module/transform.rs

@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: LGPL-3.0-or-later
 // See Notices.txt for copyright information
+pub mod deduce_resets;
 pub mod simplify_enums;
 pub mod simplify_memories;
 pub mod visit;

crates/fayalite/src/module/transform/simplify_enums.rs

@@ -764,7 +764,9 @@ impl Folder for State {
             | ExprEnum::ModuleIO(_)
             | ExprEnum::Instance(_)
             | ExprEnum::Wire(_)
-            | ExprEnum::Reg(_) => op.default_fold(self),
+            | ExprEnum::Reg(_)
+            | ExprEnum::RegSync(_)
+            | ExprEnum::RegAsync(_) => op.default_fold(self),
         }
     }
 

crates/fayalite/src/module/transform/visit.rs

@@ -29,7 +29,7 @@ use crate::{
         StmtInstance, StmtMatch, StmtReg, StmtWire,
     },
     reg::Reg,
-    reset::{AsyncReset, Reset, SyncReset},
+    reset::{AsyncReset, Reset, ResetType, SyncReset},
     source_location::SourceLocation,
     ty::{CanonicalType, Type},
     wire::Wire,

crates/fayalite/src/reg.rs

@@ -5,21 +5,22 @@ use crate::{
     expr::{Expr, Flow},
     intern::Interned,
     module::{NameId, ScopedNameId},
+    reset::{Reset, ResetType},
     source_location::SourceLocation,
     ty::{CanonicalType, Type},
 };
 use std::fmt;
 
 #[derive(Copy, Clone, Eq, PartialEq, Hash)]
-pub struct Reg<T: Type> {
+pub struct Reg<T: Type, R: ResetType = Reset> {
     name: ScopedNameId,
     source_location: SourceLocation,
     ty: T,
-    clock_domain: Expr<ClockDomain>,
+    clock_domain: Expr<ClockDomain<R>>,
     init: Option<Expr<T>>,
 }
 
-impl<T: Type + fmt::Debug> fmt::Debug for Reg<T> {
+impl<T: Type + fmt::Debug, R: ResetType> fmt::Debug for Reg<T, R> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let Self {
             name,
@@ -37,8 +38,8 @@ impl<T: Type + fmt::Debug> fmt::Debug for Reg<T> {
     }
 }
 
-impl<T: Type> Reg<T> {
+impl<T: Type, R: ResetType> Reg<T, R> {
-    pub fn canonical(&self) -> Reg<CanonicalType> {
+    pub fn canonical(&self) -> Reg<CanonicalType, R> {
         let Self {
             name,
             source_location,
@@ -59,7 +60,7 @@ impl<T: Type> Reg<T> {
         scoped_name: ScopedNameId,
         source_location: SourceLocation,
         ty: T,
-        clock_domain: Expr<ClockDomain>,
+        clock_domain: Expr<ClockDomain<R>>,
         init: Option<Expr<T>>,
     ) -> Self {
         assert!(
@@ -98,7 +99,7 @@ impl<T: Type> Reg<T> {
     pub fn scoped_name(&self) -> ScopedNameId {
         self.name
     }
-    pub fn clock_domain(&self) -> Expr<ClockDomain> {
+    pub fn clock_domain(&self) -> Expr<ClockDomain<R>> {
         self.clock_domain
     }
     pub fn init(&self) -> Option<Expr<T>> {

crates/fayalite/src/reset.rs

@@ -1,8 +1,9 @@
 // SPDX-License-Identifier: LGPL-3.0-or-later
 // See Notices.txt for copyright information
 use crate::{
-    expr::{Expr, ToExpr},
+    clock::Clock,
-    int::Bool,
+    expr::{ops, Expr, ToExpr},
+    int::{Bool, SInt, UInt},
     source_location::SourceLocation,
     ty::{impl_match_variant_as_self, CanonicalType, StaticType, Type, TypeProperties},
 };
@@ -11,10 +12,33 @@ mod sealed {
     pub trait ResetTypeSealed {}
 }
 
-pub trait ResetType: StaticType<MaskType = Bool> + sealed::ResetTypeSealed {}
+pub trait ResetType:
+    StaticType<MaskType = Bool>
+    + sealed::ResetTypeSealed
+    + ops::ExprCastTo<Bool>
+    + ops::ExprCastTo<Reset>
+    + ops::ExprCastTo<SyncReset>
+    + ops::ExprCastTo<AsyncReset>
+    + ops::ExprCastTo<Clock>
+    + ops::ExprCastTo<UInt<1>>
+    + ops::ExprCastTo<SInt<1>>
+    + ops::ExprCastTo<UInt>
+    + ops::ExprCastTo<SInt>
+{
+    fn dispatch<D: ResetTypeDispatch>(input: D::Input<Self>, dispatch: D) -> D::Output<Self>;
+}
+
+pub trait ResetTypeDispatch: Sized {
+    type Input<T: ResetType>;
+    type Output<T: ResetType>;
+
+    fn reset(self, input: Self::Input<Reset>) -> Self::Output<Reset>;
+    fn sync_reset(self, input: Self::Input<SyncReset>) -> Self::Output<SyncReset>;
+    fn async_reset(self, input: Self::Input<AsyncReset>) -> Self::Output<AsyncReset>;
+}
 
 macro_rules! reset_type {
-    ($name:ident, $Trait:ident::$trait_fn:ident, $is_castable_from_bits:literal) => {
+    ($name:ident, $(#[$impl_trait:ident])? $Trait:ident::$trait_fn:ident, $is_castable_from_bits:literal, $dispatch_fn:ident) => {
         #[derive(Copy, Clone, Eq, PartialEq, Hash, Debug, Default)]
         pub struct $name;
 
@@ -67,7 +91,14 @@ macro_rules! reset_type {
 
         impl sealed::ResetTypeSealed for $name {}
 
-        impl ResetType for $name {}
+        impl ResetType for $name {
+            fn dispatch<D: ResetTypeDispatch>(
+                input: D::Input<Self>,
+                dispatch: D,
+            ) -> D::Output<Self> {
+                dispatch.$dispatch_fn(input)
+            }
+        }
 
         pub trait $Trait {
             fn $trait_fn(&self) -> Expr<$name>;
@@ -91,20 +122,21 @@ macro_rules! reset_type {
             }
         }
 
-        impl $Trait for Expr<$name> {
+        $($impl_trait $Trait for Expr<$name> {
             fn $trait_fn(&self) -> Expr<$name> {
                 *self
             }
-        }
+        })?
     };
 }
 
-reset_type!(AsyncReset, ToAsyncReset::to_async_reset, true);
+reset_type!(AsyncReset, #[impl] ToAsyncReset::to_async_reset, true, async_reset);
-reset_type!(SyncReset, ToSyncReset::to_sync_reset, true);
+reset_type!(SyncReset, #[impl] ToSyncReset::to_sync_reset, true, sync_reset);
 reset_type!(
     Reset,
     ToReset::to_reset,
-    false // Reset is not castable from bits because we don't know if it's async or sync
+    false, // Reset is not castable from bits because we don't know if it's async or sync
+    reset
 );
 
 impl ToSyncReset for bool {

crates/fayalite/src/sim/time.rs

@@ -0,0 +1,397 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+// See Notices.txt for copyright information
+use std::{
+    fmt,
+    ops::{Add, AddAssign, Sub, SubAssign},
+    time::Duration,
+};
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
+pub struct SimInstant {
+    time_since_start: SimDuration,
+}
+
+impl SimInstant {
+    pub const fn checked_add(self, duration: SimDuration) -> Option<Self> {
+        let Some(time_since_start) = self.time_since_start.checked_add(duration) else {
+            return None;
+        };
+        Some(SimInstant { time_since_start })
+    }
+    pub const fn checked_duration_since(self, earlier: Self) -> Option<SimDuration> {
+        self.time_since_start.checked_sub(earlier.time_since_start)
+    }
+    pub const fn checked_sub(self, duration: SimDuration) -> Option<Self> {
+        let Some(time_since_start) = self.time_since_start.checked_sub(duration) else {
+            return None;
+        };
+        Some(SimInstant { time_since_start })
+    }
+    #[track_caller]
+    pub const fn duration_since(self, earlier: Self) -> SimDuration {
+        let Some(retval) = self.checked_duration_since(earlier) else {
+            panic!(
+                "tried to compute the duration since a later time -- durations can't be negative"
+            );
+        };
+        retval
+    }
+    pub const fn saturating_duration_since(self, earlier: Self) -> SimDuration {
+        let Some(retval) = self.checked_duration_since(earlier) else {
+            return SimDuration::ZERO;
+        };
+        retval
+    }
+}
+
+impl Add<SimDuration> for SimInstant {
+    type Output = SimInstant;
+
+    #[track_caller]
+    fn add(mut self, rhs: SimDuration) -> Self::Output {
+        self += rhs;
+        self
+    }
+}
+
+impl AddAssign<SimDuration> for SimInstant {
+    #[track_caller]
+    fn add_assign(&mut self, rhs: SimDuration) {
+        self.time_since_start += rhs;
+    }
+}
+
+impl Add<SimInstant> for SimDuration {
+    type Output = SimInstant;
+
+    #[track_caller]
+    fn add(self, rhs: SimInstant) -> Self::Output {
+        rhs.add(self)
+    }
+}
+
+impl Sub for SimInstant {
+    type Output = SimDuration;
+
+    #[track_caller]
+    fn sub(self, rhs: SimInstant) -> Self::Output {
+        self.duration_since(rhs)
+    }
+}
+
+impl Sub<SimDuration> for SimInstant {
+    type Output = SimInstant;
+
+    #[track_caller]
+    fn sub(self, rhs: SimDuration) -> Self::Output {
+        let Some(retval) = self.checked_sub(rhs) else {
+            panic!("SimInstant underflow");
+        };
+        retval
+    }
+}
+
+impl SubAssign<SimDuration> for SimInstant {
+    #[track_caller]
+    fn sub_assign(&mut self, rhs: SimDuration) {
+        *self = *self - rhs;
+    }
+}
+
+impl SimInstant {
+    pub const START: SimInstant = SimInstant {
+        time_since_start: SimDuration::ZERO,
+    };
+}
+
+impl fmt::Debug for SimInstant {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.time_since_start.fmt(f)
+    }
+}
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Default)]
+pub struct SimDuration {
+    attos: u128,
+}
+
+impl AddAssign for SimDuration {
+    #[track_caller]
+    fn add_assign(&mut self, rhs: SimDuration) {
+        *self = *self + rhs;
+    }
+}
+
+impl Add for SimDuration {
+    type Output = SimDuration;
+
+    #[track_caller]
+    fn add(self, rhs: SimDuration) -> Self::Output {
+        SimDuration {
+            attos: self
+                .attos
+                .checked_add(rhs.attos)
+                .expect("overflow adding durations"),
+        }
+    }
+}
+
+impl Sub for SimDuration {
+    type Output = Self;
+
+    #[track_caller]
+    fn sub(self, rhs: Self) -> Self::Output {
+        SimDuration {
+            attos: self
+                .attos
+                .checked_add(rhs.attos)
+                .expect("underflow subtracting durations -- durations can't be negative"),
+        }
+    }
+}
+
+impl SubAssign for SimDuration {
+    #[track_caller]
+    fn sub_assign(&mut self, rhs: Self) {
+        *self = *self - rhs;
+    }
+}
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, Default)]
+pub struct SimDurationParts {
+    pub attos: u16,
+    pub femtos: u16,
+    pub picos: u16,
+    pub nanos: u16,
+    pub micros: u16,
+    pub millis: u16,
+    pub secs: u128,
+}
+
+macro_rules! impl_duration_units {
+    (
+        $(
+            #[unit_const = $UNIT:ident, from_units = $from_units:ident, as_units = $as_units:ident, units = $units:ident, suffix = $suffix:literal]
+            const $log10_units_per_sec:ident: u32 = $log10_units_per_sec_value:expr;
+        )*
+    ) => {
+        impl SimDuration {
+            $(
+                const $log10_units_per_sec: u32 = $log10_units_per_sec_value;
+                pub const fn $from_units($units: u128) -> Self {
+                    Self::from_units_helper::<{ Self::$log10_units_per_sec }>($units)
+                }
+                pub const fn $as_units(self) -> u128 {
+                    self.attos / const { 10u128.pow(Self::LOG10_ATTOS_PER_SEC - Self::$log10_units_per_sec) }
+                }
+            )*
+            pub const fn to_parts(mut self) -> SimDurationParts {
+                $(
+                    let $units = self.attos / const { 10u128.pow(Self::LOG10_ATTOS_PER_SEC - Self::$log10_units_per_sec) };
+                    self.attos %= const { 10u128.pow(Self::LOG10_ATTOS_PER_SEC - Self::$log10_units_per_sec) };
+                )*
+                SimDurationParts {
+                    $($units: $units as _,)*
+                }
+            }
+            pub const fn from_parts_checked(parts: SimDurationParts) -> Option<Self> {
+                let attos = 0u128;
+                $(
+                    let Some(product) = const { 10u128.pow(Self::LOG10_ATTOS_PER_SEC - Self::$log10_units_per_sec) }.checked_mul(parts.$units as u128) else {
+                        return None;
+                    };
+                    let Some(attos) = attos.checked_add(product) else {
+                        return None;
+                    };
+                )*
+                Some(Self {
+                    attos,
+                })
+            }
+        }
+
+        impl fmt::Debug for SimDuration {
+            fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+                let ilog10_attos = match self.attos.checked_ilog10() {
+                    Some(v) => v,
+                    None => Self::LOG10_ATTOS_PER_SEC,
+                };
+                let (suffix, int, fraction, fraction_digits) =
+                    match Self::LOG10_ATTOS_PER_SEC.saturating_sub(ilog10_attos) {
+                    $(
+                        ..=Self::$log10_units_per_sec => {
+                            let divisor = const { 10u128.pow(Self::LOG10_ATTOS_PER_SEC - Self::$log10_units_per_sec) };
+                            (
+                                $suffix,
+                                self.attos / divisor,
+                                self.attos % divisor,
+                                (Self::LOG10_ATTOS_PER_SEC - Self::$log10_units_per_sec) as usize,
+                            )
+                        },
+                    )*
+                    _ => unreachable!(),
+                };
+                write!(f, "{int}")?;
+                if fraction != 0 {
+                    write!(f, ".{fraction:0fraction_digits$}")?;
+                }
+                write!(f, " {suffix}")
+            }
+        }
+
+        #[cfg(test)]
+        #[test]
+        fn test_duration_debug() {
+            $(
+                assert_eq!(
+                    format!("{:?}", SimDuration::$from_units(123)),
+                    concat!("123 ", $suffix)
+                );
+                assert_eq!(
+                    format!("{:?}", SimDuration::$from_units(1)),
+                    concat!("1 ", $suffix),
+                );
+                let mut v = SimDuration::$from_units(1);
+                if v.attos < 1 << 53 {
+                    v.attos += 1;
+                    assert_eq!(
+                        format!("{v:?}"),
+                        format!("{} {}", v.attos as f64 / 10.0f64.powf((SimDuration::LOG10_ATTOS_PER_SEC - SimDuration::$log10_units_per_sec) as f64), $suffix),
+                        "1 {} + 1 as == {} as", $suffix, v.attos,
+                    );
+                }
+            )*
+        }
+    };
+}
+
+impl_duration_units! {
+    #[unit_const = SECOND, from_units = from_secs, as_units = as_secs, units = secs, suffix = "s"]
+    const LOG10_SECS_PER_SEC: u32 = 0;
+    #[unit_const = MILLISECOND, from_units = from_millis, as_units = as_millis, units = millis, suffix = "ms"]
+    const LOG10_MILLIS_PER_SEC: u32 = 3;
+    #[unit_const = MICROSECOND, from_units = from_micros, as_units = as_micros, units = micros, suffix = "μs"]
+    const LOG10_MICROS_PER_SEC: u32 = 6;
+    #[unit_const = NANOSECOND, from_units = from_nanos, as_units = as_nanos, units = nanos, suffix = "ns"]
+    const LOG10_NANOS_PER_SEC: u32 = 9;
+    #[unit_const = PICOSECOND, from_units = from_picos, as_units = as_picos, units = picos, suffix = "ps"]
+    const LOG10_PICOS_PER_SEC: u32 = 12;
+    #[unit_const = FEMTOSECOND, from_units = from_femtos, as_units = as_femtos, units = femtos, suffix = "fs"]
+    const LOG10_FEMTOS_PER_SEC: u32 = 15;
+    #[unit_const = ATTOSECOND, from_units = from_attos, as_units = as_attos, units = attos, suffix = "as"]
+    const LOG10_ATTOS_PER_SEC: u32 = 18;
+}
+
+impl SimDuration {
+    const fn from_units_helper<const UNITS_PER_SEC: u32>(units: u128) -> Self {
+        let Some(attos) =
+            units.checked_mul(const { 10u128.pow(Self::LOG10_ATTOS_PER_SEC - UNITS_PER_SEC) })
+        else {
+            panic!("duration too big");
+        };
+        Self { attos }
+    }
+    pub const ZERO: SimDuration = SimDuration::from_secs(0);
+    pub const fn from_parts(parts: SimDurationParts) -> Self {
+        match Self::from_parts_checked(parts) {
+            Some(v) => v,
+            None => panic!("duration too big"),
+        }
+    }
+    pub const fn abs_diff(self, other: Self) -> Self {
+        Self {
+            attos: self.attos.abs_diff(other.attos),
+        }
+    }
+    pub const fn checked_add(self, rhs: Self) -> Option<Self> {
+        let Some(attos) = self.attos.checked_add(rhs.attos) else {
+            return None;
+        };
+        Some(Self { attos })
+    }
+    pub const fn checked_sub(self, rhs: Self) -> Option<Self> {
+        let Some(attos) = self.attos.checked_sub(rhs.attos) else {
+            return None;
+        };
+        Some(Self { attos })
+    }
+    pub const fn is_zero(self) -> bool {
+        self.attos == 0
+    }
+    pub const fn saturating_add(self, rhs: Self) -> Self {
+        Self {
+            attos: self.attos.saturating_add(rhs.attos),
+        }
+    }
+    pub const fn saturating_sub(self, rhs: Self) -> Self {
+        Self {
+            attos: self.attos.saturating_sub(rhs.attos),
+        }
+    }
+    pub const fn checked_ilog10(self) -> Option<i32> {
+        let Some(ilog10_attos) = self.attos.checked_ilog10() else {
+            return None;
+        };
+        Some(ilog10_attos as i32 - Self::LOG10_ATTOS_PER_SEC as i32)
+    }
+    #[track_caller]
+    pub const fn ilog10(self) -> i32 {
+        let Some(retval) = self.checked_ilog10() else {
+            panic!("tried to take the ilog10 of 0");
+        };
+        retval
+    }
+    pub const fn checked_pow10(log10: i32, underflow_is_zero: bool) -> Option<Self> {
+        let Some(log10) = Self::LOG10_ATTOS_PER_SEC.checked_add_signed(log10) else {
+            return if log10 < 0 && underflow_is_zero {
+                Some(Self::ZERO)
+            } else {
+                None
+            };
+        };
+        let Some(attos) = 10u128.checked_pow(log10) else {
+            return None;
+        };
+        Some(Self { attos })
+    }
+    #[track_caller]
+    pub const fn pow10(log10: i32) -> Self {
+        let Some(retval) = Self::checked_pow10(log10, true) else {
+            panic!("pow10 overflowed");
+        };
+        retval
+    }
+    pub const fn is_power_of_ten(self) -> bool {
+        const TEN: u128 = 10;
+        const NUMBER_OF_POWERS_OF_TEN: usize = {
+            let mut n = 0;
+            while let Some(_) = TEN.checked_pow(n as u32) {
+                n += 1;
+            }
+            n
+        };
+        const POWERS_OF_TEN: [u128; NUMBER_OF_POWERS_OF_TEN] = {
+            let mut retval = [0; NUMBER_OF_POWERS_OF_TEN];
+            let mut i = 0;
+            while i < NUMBER_OF_POWERS_OF_TEN {
+                retval[i] = TEN.pow(i as u32);
+                i += 1;
+            }
+            retval
+        };
+        let mut i = 0;
+        while i < NUMBER_OF_POWERS_OF_TEN {
+            if self.attos == POWERS_OF_TEN[i] {
+                return true;
+            }
+            i += 1;
+        }
+        false
+    }
+}
+
+impl From<Duration> for SimDuration {
+    fn from(duration: Duration) -> Self {
+        Self::from_nanos(duration.as_nanos())
+    }
+}

crates/fayalite/src/util.rs

@@ -24,7 +24,8 @@ pub use scoped_ref::ScopedRef;
 
 #[doc(inline)]
 pub use misc::{
-    interned_bit, iter_eq_by, BitSliceWriteWithBase, DebugAsDisplay, DebugAsRawString, MakeMutSlice,
+    get_many_mut, interned_bit, iter_eq_by, BitSliceWriteWithBase, DebugAsDisplay,
+    DebugAsRawString, MakeMutSlice, RcWriter,
 };
 
 pub mod job_server;

crates/fayalite/src/util/misc.rs

@@ -3,6 +3,7 @@
 use crate::intern::{Intern, Interned};
 use bitvec::{bits, order::Lsb0, slice::BitSlice, view::BitView};
 use std::{
+    cell::Cell,
     fmt::{self, Debug, Write},
     rc::Rc,
     sync::{Arc, OnceLock},
@@ -94,9 +95,15 @@ pub fn interned_bit(v: bool) -> Interned<BitSlice> {
     RETVAL.get_or_init(|| [bits![0; 1].intern(), bits![1; 1].intern()])[v as usize]
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone)]
 pub struct BitSliceWriteWithBase<'a>(pub &'a BitSlice);
 
+impl<'a> Debug for BitSliceWriteWithBase<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{self:#x}")
+    }
+}
+
 impl BitSliceWriteWithBase<'_> {
     fn fmt_with_base<const BITS_PER_DIGIT: usize, const UPPER_CASE: bool>(
         self,
@@ -155,3 +162,66 @@ impl fmt::UpperHex for BitSliceWriteWithBase<'_> {
         self.fmt_with_base::<4, true>(f)
     }
 }
+
+#[inline]
+#[track_caller]
+pub fn get_many_mut<T, const N: usize>(slice: &mut [T], indexes: [usize; N]) -> [&mut T; N] {
+    for i in 0..N {
+        for j in 0..i {
+            assert!(indexes[i] != indexes[j], "duplicate index");
+        }
+        assert!(indexes[i] < slice.len(), "index out of bounds");
+    }
+    // Safety: checked that no indexes are duplicates and no indexes are out of bounds
+    unsafe {
+        let base = slice.as_mut_ptr(); // convert to a raw pointer before loop to avoid aliasing with &mut [T]
+        std::array::from_fn(|i| &mut *base.add(indexes[i]))
+    }
+}
+
+#[derive(Clone, Default)]
+pub struct RcWriter(Rc<Cell<Vec<u8>>>);
+
+impl Debug for RcWriter {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.borrow_impl(|buf| {
+            f.debug_tuple("RcWriter")
+                .field(&DebugAsDisplay(format_args!("b\"{}\"", buf.escape_ascii())))
+                .finish()
+        })
+    }
+}
+
+impl RcWriter {
+    fn borrow_impl<R>(&self, f: impl FnOnce(&mut Vec<u8>) -> R) -> R {
+        let buf = Cell::take(&self.0);
+        struct PutBackOnDrop<'a> {
+            buf: Vec<u8>,
+            this: &'a RcWriter,
+        }
+        impl Drop for PutBackOnDrop<'_> {
+            fn drop(&mut self) {
+                self.this.0.set(std::mem::take(&mut self.buf));
+            }
+        }
+        let mut buf = PutBackOnDrop { buf, this: self };
+        f(&mut buf.buf)
+    }
+    pub fn borrow<R>(&mut self, f: impl FnOnce(&mut Vec<u8>) -> R) -> R {
+        self.borrow_impl(f)
+    }
+    pub fn take(&mut self) -> Vec<u8> {
+        Cell::take(&self.0)
+    }
+}
+
+impl std::io::Write for RcWriter {
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        self.borrow(|v| v.extend_from_slice(buf));
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        Ok(())
+    }
+}

crates/fayalite/src/util/ready_valid.rs

@@ -49,6 +49,18 @@ impl<T: Type> ReadyValid<T> {
     }
 }
 
+/// This debug port is only meant to assist the formal proof of the queue.
+#[cfg(test)]
+#[doc(hidden)]
+#[hdl]
+pub struct QueueDebugPort<Element, Index> {
+    #[hdl(flip)]
+    index_to_check: Index,
+    stored: Element,
+    inp_index: Index,
+    out_index: Index,
+}
+
 #[hdl_module]
 pub fn queue<T: Type>(
     ty: T,
@@ -178,6 +190,22 @@ pub fn queue<T: Type>(
             }
         }
     }
+    // These debug ports expose some internal state during the Induction phase
+    // of Formal Verification. They are not present in normal use.
+    #[cfg(test)]
+    {
+        #[hdl]
+        let dbg: QueueDebugPort<T, UInt> = m.output(QueueDebugPort[ty][index_ty]);
+        // read the memory word currently stored at some fixed index
+        let debug_port = mem.new_read_port();
+        connect(debug_port.addr, dbg.index_to_check);
+        connect(debug_port.en, true);
+        connect(debug_port.clk, cd.clk);
+        connect(dbg.stored, debug_port.data);
+        // also expose the current read and write indices
+        connect(dbg.inp_index, inp_index_reg);
+        connect(dbg.out_index, out_index_reg);
+    }
 }
 
 #[cfg(test)]
@@ -196,13 +224,23 @@ mod tests {
             format_args!("test_queue_{capacity}_{inp_ready_is_comb}_{out_valid_is_comb}"),
             queue_test(capacity, inp_ready_is_comb, out_valid_is_comb),
             FormalMode::Prove,
-            14,
+            2,
             None,
             ExportOptions {
                 simplify_enums: Some(SimplifyEnumsKind::ReplaceWithBundleOfUInts),
                 ..ExportOptions::default()
             },
         );
+        /// Formal verification of the FIFO queue
+        ///
+        /// The strategy derives from the observation that, if we filter its
+        /// input and output streams to consider just one in every N reads and
+        /// writes (where N is the FIFO capacity), then the FIFO effectively
+        /// behaves as a one-entry FIFO.
+        ///
+        /// In particular, any counterexample of the full FIFO behaving badly
+        /// will also be caught by one of the filtered versions (one which
+        /// happens to be in phase with the offending input or output).
         #[hdl_module]
         fn queue_test(capacity: NonZeroUsize, inp_ready_is_comb: bool, out_valid_is_comb: bool) {
             #[hdl]
@@ -217,6 +255,8 @@ mod tests {
                     rst: formal_reset().to_reset(),
                 },
             );
+
+            // random input data
             #[hdl]
             let inp_data: HdlOption<UInt<8>> = wire();
             #[hdl]
@@ -225,16 +265,26 @@ mod tests {
             } else {
                 connect(inp_data, HdlNone());
             }
+
+            // assert output ready at random
             #[hdl]
             let out_ready: Bool = wire();
             connect(out_ready, any_seq(Bool));
-            let index_ty: UInt<32> = UInt::TYPE;
+
+            // The current number of elements in the FIFO ranges from zero to
+            // maximum capacity, inclusive.
+            let count_ty = UInt::range_inclusive(0..=capacity.get());
+            // type for counters that wrap around at the FIFO capacity
+            let index_ty = UInt::range(0..capacity.get());
+
+            // among all entries of the FIFO internal circular memory, choose
+            // one at random to check
             #[hdl]
-            let index_to_check = wire();
+            let index_to_check = wire(index_ty);
             connect(index_to_check, any_const(index_ty));
-            let index_max = !index_ty.zero();
+            hdl_assume(clk, index_to_check.cmp_lt(capacity.get()), "");
-            // we saturate at index_max, so only check indexes where we properly maintain position
+
-            hdl_assume(clk, index_to_check.cmp_ne(index_max), "");
+            // instantiate and connect the queue
             #[hdl]
             let dut = instance(queue(
                 UInt[ConstUsize::<8>],
@@ -245,109 +295,172 @@ mod tests {
             connect(dut.cd, cd);
             connect(dut.inp.data, inp_data);
             connect(dut.out.ready, out_ready);
-            hdl_assume(
-                clk,
-                index_to_check.cmp_ne(!Expr::ty(index_to_check).zero()),
-                "",
-            );
 
+            // Keep an independent count of words in the FIFO. Ensure that
+            // it's always correct, and never overflows.
             #[hdl]
-            let expected_count_reg = reg_builder().clock_domain(cd).reset(0u32);
+            let expected_count_reg = reg_builder().clock_domain(cd).reset(count_ty.zero());
-            #[hdl]
-            let next_expected_count = wire();
-            connect(next_expected_count, expected_count_reg);
-            connect(expected_count_reg, next_expected_count);
             #[hdl]
             if ReadyValid::firing(dut.inp) & !ReadyValid::firing(dut.out) {
-                connect_any(next_expected_count, expected_count_reg + 1u8);
+                hdl_assert(clk, expected_count_reg.cmp_ne(capacity.get()), "");
+                connect_any(expected_count_reg, expected_count_reg + 1u8);
             } else if !ReadyValid::firing(dut.inp) & ReadyValid::firing(dut.out) {
-                connect_any(next_expected_count, expected_count_reg - 1u8);
+                hdl_assert(clk, expected_count_reg.cmp_ne(count_ty.zero()), "");
+                connect_any(expected_count_reg, expected_count_reg - 1u8);
             }
-            hdl_assert(cd.clk, expected_count_reg.cmp_eq(dut.count), "");
+            hdl_assert(clk, expected_count_reg.cmp_eq(dut.count), "");
-
-            #[hdl]
-            let prev_out_ready_reg = reg_builder().clock_domain(cd).reset(!0_hdl_u3);
-            connect_any(
-                prev_out_ready_reg,
-                (prev_out_ready_reg << 1) | out_ready.cast_to(UInt[1]),
-            );
-            #[hdl]
-            let prev_inp_valid_reg = reg_builder().clock_domain(cd).reset(!0_hdl_u3);
-            connect_any(
-                prev_inp_valid_reg,
-                (prev_inp_valid_reg << 1) | HdlOption::is_some(inp_data).cast_to(UInt[1]),
-            );
-            hdl_assume(
-                clk,
-                (prev_out_ready_reg & prev_inp_valid_reg).cmp_ne(0u8),
-                "",
-            );
 
+            // keep an independent write index into the FIFO's circular buffer
             #[hdl]
             let inp_index_reg = reg_builder().clock_domain(cd).reset(index_ty.zero());
             #[hdl]
-            let stored_inp_data_reg = reg_builder().clock_domain(cd).reset(0u8);
+            if ReadyValid::firing(dut.inp) {
-
                 #[hdl]
-            if let HdlSome(data) = ReadyValid::firing_data(dut.inp) {
+                if inp_index_reg.cmp_ne(capacity.get() - 1) {
-                #[hdl]
-                if inp_index_reg.cmp_lt(index_max) {
                     connect_any(inp_index_reg, inp_index_reg + 1u8);
-                    #[hdl]
+                } else {
-                    if inp_index_reg.cmp_eq(index_to_check) {
+                    connect_any(inp_index_reg, 0_hdl_u0);
-                        connect(stored_inp_data_reg, data);
-                    }
                 }
             }
 
-            #[hdl]
+            // keep an independent read index into the FIFO's circular buffer
-            if inp_index_reg.cmp_lt(index_to_check) {
-                hdl_assert(clk, stored_inp_data_reg.cmp_eq(0u8), "");
-            }
-
             #[hdl]
             let out_index_reg = reg_builder().clock_domain(cd).reset(index_ty.zero());
             #[hdl]
-            let stored_out_data_reg = reg_builder().clock_domain(cd).reset(0u8);
+            if ReadyValid::firing(dut.out) {
-
                 #[hdl]
-            if let HdlSome(data) = ReadyValid::firing_data(dut.out) {
+                if out_index_reg.cmp_ne(capacity.get() - 1) {
-                #[hdl]
-                if out_index_reg.cmp_lt(index_max) {
                     connect_any(out_index_reg, out_index_reg + 1u8);
-                    #[hdl]
-                    if out_index_reg.cmp_eq(index_to_check) {
-                        connect(stored_out_data_reg, data);
-                    }
-                }
-            }
-
-            #[hdl]
-            if out_index_reg.cmp_lt(index_to_check) {
-                hdl_assert(clk, stored_out_data_reg.cmp_eq(0u8), "");
-            }
-
-            hdl_assert(clk, inp_index_reg.cmp_ge(out_index_reg), "");
-
-            #[hdl]
-            if inp_index_reg.cmp_lt(index_max) & out_index_reg.cmp_lt(index_max) {
-                hdl_assert(
-                    clk,
-                    expected_count_reg.cmp_eq(inp_index_reg - out_index_reg),
-                    "",
-                );
                 } else {
-                hdl_assert(
+                    connect_any(out_index_reg, 0_hdl_u0);
-                    clk,
+                }
-                    expected_count_reg.cmp_ge(inp_index_reg - out_index_reg),
-                    "",
-                );
             }
 
+            // filter the input data stream, predicated by the read index
+            // matching the chosen position in the FIFO's circular buffer
             #[hdl]
-            if inp_index_reg.cmp_gt(index_to_check) & out_index_reg.cmp_gt(index_to_check) {
+            let inp_index_matches = wire();
-                hdl_assert(clk, stored_inp_data_reg.cmp_eq(stored_out_data_reg), "");
+            connect(inp_index_matches, inp_index_reg.cmp_eq(index_to_check));
+            #[hdl]
+            let inp_firing_data = wire();
+            connect(inp_firing_data, HdlNone());
+            #[hdl]
+            if inp_index_matches {
+                connect(inp_firing_data, ReadyValid::firing_data(dut.inp));
             }
+
+            // filter the output data stream, predicated by the write index
+            // matching the chosen position in the FIFO's circular buffer
+            #[hdl]
+            let out_index_matches = wire();
+            connect(out_index_matches, out_index_reg.cmp_eq(index_to_check));
+            #[hdl]
+            let out_firing_data = wire();
+            connect(out_firing_data, HdlNone());
+            #[hdl]
+            if out_index_matches {
+                connect(out_firing_data, ReadyValid::firing_data(dut.out));
+            }
+
+            // Implement a one-entry FIFO and ensure its equivalence to the
+            // filtered FIFO.
+            //
+            // the holding register for our one-entry FIFO
+            #[hdl]
+            let stored_reg = reg_builder().clock_domain(cd).reset(HdlNone());
+            #[hdl]
+            match stored_reg {
+                // If the holding register is empty...
+                HdlNone => {
+                    #[hdl]
+                    match inp_firing_data {
+                        // ... and we are not receiving data, then we must not
+                        // transmit any data.
+                        HdlNone => hdl_assert(clk, HdlOption::is_none(out_firing_data), ""),
+                        // If we are indeed receiving some data...
+                        HdlSome(data_in) => {
+                            #[hdl]
+                            match out_firing_data {
+                                // ... and transmitting at the same time, we
+                                // must be transmitting the input data itself,
+                                // since the holding register is empty.
+                                HdlSome(data_out) => hdl_assert(clk, data_out.cmp_eq(data_in), ""),
+                                // If we are receiving, but not transmitting,
+                                // store the received data in the holding
+                                // register.
+                                HdlNone => connect(stored_reg, HdlSome(data_in)),
+                            }
+                        }
+                    }
+                }
+                // If there is some value stored in the holding register...
+                HdlSome(stored) => {
+                    #[hdl]
+                    match out_firing_data {
+                        // ... and we are not transmitting it, we cannot
+                        // receive any more data.
+                        HdlNone => hdl_assert(clk, HdlOption::is_none(inp_firing_data), ""),
+                        // If we are transmitting a previously stored value...
+                        HdlSome(data_out) => {
+                            // ... it must be the same data we stored earlier.
+                            hdl_assert(clk, data_out.cmp_eq(stored), "");
+                            // Also, accept new data, if any. Otherwise,
+                            // let the holding register become empty.
+                            connect(stored_reg, inp_firing_data);
+                        }
+                    }
+                }
+            }
+
+            // from now on, some extra assertions in order to pass induction
+
+            // sync the holding register, when it's occupied, to the
+            // corresponding entry in the FIFO's circular buffer
+            connect(dut.dbg.index_to_check, index_to_check);
+            #[hdl]
+            if let HdlSome(stored) = stored_reg {
+                hdl_assert(clk, stored.cmp_eq(dut.dbg.stored), "");
+            }
+
+            // sync the read and write indices
+            hdl_assert(clk, inp_index_reg.cmp_eq(dut.dbg.inp_index), "");
+            hdl_assert(clk, out_index_reg.cmp_eq(dut.dbg.out_index), "");
+
+            // the indices should never go past the capacity, but induction
+            // doesn't know that...
+            hdl_assert(clk, inp_index_reg.cmp_lt(capacity.get()), "");
+            hdl_assert(clk, out_index_reg.cmp_lt(capacity.get()), "");
+
+            // strongly constrain the state of the holding register
+            //
+            // The holding register is full if and only if the corresponding
+            // FIFO entry was written to and not yet read. In other words, if
+            // the number of pending reads until the chosen entry is read out
+            // is greater than the current FIFO count, then the entry couldn't
+            // be in the FIFO in the first place.
+            #[hdl]
+            let pending_reads: UInt = wire(index_ty);
+            // take care of wrap-around when subtracting indices, add the
+            // capacity amount to keep the result positive if necessary
+            #[hdl]
+            if index_to_check.cmp_ge(out_index_reg) {
+                connect(pending_reads, index_to_check - out_index_reg);
+            } else {
+                connect(
+                    pending_reads,
+                    index_to_check + capacity.get() - out_index_reg,
+                );
+            }
+            // check whether the chosen entry is in the FIFO
+            #[hdl]
+            let expected_stored: Bool = wire();
+            connect(expected_stored, pending_reads.cmp_lt(dut.count));
+            // sync with the state of the holding register
+            hdl_assert(
+                clk,
+                expected_stored.cmp_eq(HdlOption::is_some(stored_reg)),
+                "",
+            );
         }
     }
 
@@ -430,4 +543,24 @@ mod tests {
     fn test_4_true_true() {
         test_queue(NonZero::new(4).unwrap(), true, true);
     }
+
+    #[test]
+    fn test_many_false_false() {
+        test_queue(NonZero::new((2 << 16) - 5).unwrap(), false, false);
+    }
+
+    #[test]
+    fn test_many_false_true() {
+        test_queue(NonZero::new((2 << 16) - 5).unwrap(), false, true);
+    }
+
+    #[test]
+    fn test_many_true_false() {
+        test_queue(NonZero::new((2 << 16) - 5).unwrap(), true, false);
+    }
+
+    #[test]
+    fn test_many_true_true() {
+        test_queue(NonZero::new((2 << 16) - 5).unwrap(), true, true);
+    }
 }

crates/fayalite/src/wire.rs

@@ -37,6 +37,18 @@ impl<T: Type> Wire<T> {
             ty: ty.canonical(),
         }
     }
+    pub fn from_canonical(v: Wire<CanonicalType>) -> Self {
+        let Wire {
+            name,
+            source_location,
+            ty,
+        } = v;
+        Self {
+            name,
+            source_location,
+            ty: T::from_canonical(ty),
+        }
+    }
     pub fn ty(&self) -> T {
         self.ty
     }

crates/fayalite/tests/module.rs

@@ -2,7 +2,8 @@
 // See Notices.txt for copyright information
 use fayalite::{
     assert_export_firrtl, firrtl::ExportOptions, intern::Intern,
-    module::transform::simplify_enums::SimplifyEnumsKind, prelude::*, ty::StaticType,
+    module::transform::simplify_enums::SimplifyEnumsKind, prelude::*, reset::ResetType,
+    ty::StaticType,
 };
 use serde_json::json;
 
@@ -190,10 +191,14 @@ circuit check_array_repeat:
     };
 }
 
+pub trait UnknownTrait {}
+
+impl<T: ?Sized> UnknownTrait for T {}
+
 #[hdl_module(outline_generated)]
 pub fn check_skipped_generics<T, #[hdl(skip)] U, const N: usize, #[hdl(skip)] const M: usize>(v: U)
 where
-    T: StaticType,
+    T: StaticType + UnknownTrait,
     ConstUsize<N>: KnownSize,
     U: std::fmt::Display,
 {
@@ -375,18 +380,18 @@ circuit check_written_inside_both_if_else:
     };
 }
 
-#[hdl(outline_generated)]
+#[hdl(outline_generated, cmp_eq)]
 pub struct TestStruct<T> {
     pub a: T,
     pub b: UInt<8>,
 }
 
-#[hdl(outline_generated)]
+#[hdl(outline_generated, cmp_eq)]
 pub struct TestStruct2 {
     pub v: UInt<8>,
 }
 
-#[hdl(outline_generated)]
+#[hdl(outline_generated, cmp_eq)]
 pub struct TestStruct3 {}
 
 #[hdl_module(outline_generated)]
@@ -4026,3 +4031,519 @@ circuit check_enum_connect_any:
 ",
     };
 }
+
+#[hdl_module(outline_generated)]
+pub fn check_deduce_resets<T: ResetType>(ty: T) {
+    #[hdl]
+    let cd: ClockDomain<T> = m.input(ClockDomain[ty]);
+    #[hdl]
+    let my_reg = reg_builder().reset(0u8).clock_domain(cd);
+    #[hdl]
+    let u8_in: UInt<8> = m.input();
+    connect(my_reg, u8_in);
+    #[hdl]
+    let u8_out: UInt<8> = m.output();
+    connect(u8_out, my_reg);
+    #[hdl]
+    let enum_in: OneOfThree<Reset, AsyncReset, SyncReset> = m.input();
+    #[hdl]
+    let enum_out: OneOfThree<Reset, AsyncReset, SyncReset> = m.output();
+    #[hdl]
+    let reset_out: Reset = m.output();
+    connect(reset_out, cd.rst.to_reset());
+    #[hdl]
+    match enum_in {
+        OneOfThree::<_, _, _>::A(v) => {
+            connect(
+                enum_out,
+                OneOfThree[Reset][AsyncReset][SyncReset].A(cd.rst.to_reset()),
+            );
+            connect(reset_out, v);
+        }
+        OneOfThree::<_, _, _>::B(v) => {
+            connect(enum_out, OneOfThree[Reset][AsyncReset][SyncReset].B(v))
+        }
+        OneOfThree::<_, _, _>::C(v) => {
+            connect(enum_out, OneOfThree[Reset][AsyncReset][SyncReset].C(v))
+        }
+    }
+}
+
+#[test]
+fn test_deduce_resets() {
+    let _n = SourceLocation::normalize_files_for_tests();
+    let m = check_deduce_resets(Reset);
+    dbg!(m);
+    #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
+    assert_export_firrtl! {
+        m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
+        "/test/check_deduce_resets.fir": r"FIRRTL version 3.2.0
+circuit check_deduce_resets:
+    type Ty0 = {clk: Clock, rst: Reset}
+    type Ty1 = {|A: Reset, B: AsyncReset, C: UInt<1>|}
+    module check_deduce_resets: @[module-XXXXXXXXXX.rs 1:1]
+        input cd: Ty0 @[module-XXXXXXXXXX.rs 2:1]
+        input u8_in: UInt<8> @[module-XXXXXXXXXX.rs 4:1]
+        output u8_out: UInt<8> @[module-XXXXXXXXXX.rs 6:1]
+        input enum_in: Ty1 @[module-XXXXXXXXXX.rs 8:1]
+        output enum_out: Ty1 @[module-XXXXXXXXXX.rs 9:1]
+        output reset_out: Reset @[module-XXXXXXXXXX.rs 10:1]
+        regreset my_reg: UInt<8>, cd.clk, cd.rst, UInt<8>(0h0) @[module-XXXXXXXXXX.rs 3:1]
+        connect my_reg, u8_in @[module-XXXXXXXXXX.rs 5:1]
+        connect u8_out, my_reg @[module-XXXXXXXXXX.rs 7:1]
+        connect reset_out, cd.rst @[module-XXXXXXXXXX.rs 11:1]
+        match enum_in: @[module-XXXXXXXXXX.rs 12:1]
+            A(_match_arm_value):
+                connect enum_out, {|A: Reset, B: AsyncReset, C: UInt<1>|}(A, cd.rst) @[module-XXXXXXXXXX.rs 13:1]
+                connect reset_out, _match_arm_value @[module-XXXXXXXXXX.rs 14:1]
+            B(_match_arm_value_1):
+                connect enum_out, {|A: Reset, B: AsyncReset, C: UInt<1>|}(B, _match_arm_value_1) @[module-XXXXXXXXXX.rs 15:1]
+            C(_match_arm_value_2):
+                connect enum_out, {|A: Reset, B: AsyncReset, C: UInt<1>|}(C, _match_arm_value_2) @[module-XXXXXXXXXX.rs 16:1]
+",
+    };
+    fayalite::module::transform::deduce_resets::deduce_resets(m.canonical().intern_sized(), false)
+        .unwrap_err();
+    let m = fayalite::module::transform::deduce_resets::deduce_resets(
+        m.canonical().intern_sized(),
+        true,
+    )
+    .unwrap();
+    dbg!(m);
+    #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
+    assert_export_firrtl! {
+        m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
+        "/test/check_deduce_resets.fir": r"FIRRTL version 3.2.0
+circuit check_deduce_resets:
+    type Ty0 = {clk: Clock, rst: UInt<1>}
+    type Ty1 = {|A: UInt<1>, B: AsyncReset, C: UInt<1>|}
+    module check_deduce_resets: @[module-XXXXXXXXXX.rs 1:1]
+        input cd: Ty0 @[module-XXXXXXXXXX.rs 2:1]
+        input u8_in: UInt<8> @[module-XXXXXXXXXX.rs 4:1]
+        output u8_out: UInt<8> @[module-XXXXXXXXXX.rs 6:1]
+        input enum_in: Ty1 @[module-XXXXXXXXXX.rs 8:1]
+        output enum_out: Ty1 @[module-XXXXXXXXXX.rs 9:1]
+        output reset_out: UInt<1> @[module-XXXXXXXXXX.rs 10:1]
+        regreset my_reg: UInt<8>, cd.clk, cd.rst, UInt<8>(0h0) @[module-XXXXXXXXXX.rs 3:1]
+        connect my_reg, u8_in @[module-XXXXXXXXXX.rs 5:1]
+        connect u8_out, my_reg @[module-XXXXXXXXXX.rs 7:1]
+        connect reset_out, cd.rst @[module-XXXXXXXXXX.rs 11:1]
+        match enum_in: @[module-XXXXXXXXXX.rs 12:1]
+            A(_match_arm_value):
+                connect enum_out, {|A: UInt<1>, B: AsyncReset, C: UInt<1>|}(A, cd.rst) @[module-XXXXXXXXXX.rs 13:1]
+                connect reset_out, _match_arm_value @[module-XXXXXXXXXX.rs 14:1]
+            B(_match_arm_value_1):
+                connect enum_out, {|A: UInt<1>, B: AsyncReset, C: UInt<1>|}(B, _match_arm_value_1) @[module-XXXXXXXXXX.rs 15:1]
+            C(_match_arm_value_2):
+                connect enum_out, {|A: UInt<1>, B: AsyncReset, C: UInt<1>|}(C, _match_arm_value_2) @[module-XXXXXXXXXX.rs 16:1]
+",
+    };
+    let m = check_deduce_resets(SyncReset);
+    dbg!(m);
+    #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
+    assert_export_firrtl! {
+        m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
+        "/test/check_deduce_resets.fir": r"FIRRTL version 3.2.0
+circuit check_deduce_resets:
+    type Ty0 = {clk: Clock, rst: UInt<1>}
+    type Ty1 = {|A: Reset, B: AsyncReset, C: UInt<1>|}
+    module check_deduce_resets: @[module-XXXXXXXXXX.rs 1:1]
+        input cd: Ty0 @[module-XXXXXXXXXX.rs 2:1]
+        input u8_in: UInt<8> @[module-XXXXXXXXXX.rs 4:1]
+        output u8_out: UInt<8> @[module-XXXXXXXXXX.rs 6:1]
+        input enum_in: Ty1 @[module-XXXXXXXXXX.rs 8:1]
+        output enum_out: Ty1 @[module-XXXXXXXXXX.rs 9:1]
+        output reset_out: Reset @[module-XXXXXXXXXX.rs 10:1]
+        regreset my_reg: UInt<8>, cd.clk, cd.rst, UInt<8>(0h0) @[module-XXXXXXXXXX.rs 3:1]
+        connect my_reg, u8_in @[module-XXXXXXXXXX.rs 5:1]
+        connect u8_out, my_reg @[module-XXXXXXXXXX.rs 7:1]
+        connect reset_out, cd.rst @[module-XXXXXXXXXX.rs 11:1]
+        match enum_in: @[module-XXXXXXXXXX.rs 12:1]
+            A(_match_arm_value):
+                connect enum_out, {|A: Reset, B: AsyncReset, C: UInt<1>|}(A, cd.rst) @[module-XXXXXXXXXX.rs 13:1]
+                connect reset_out, _match_arm_value @[module-XXXXXXXXXX.rs 14:1]
+            B(_match_arm_value_1):
+                connect enum_out, {|A: Reset, B: AsyncReset, C: UInt<1>|}(B, _match_arm_value_1) @[module-XXXXXXXXXX.rs 15:1]
+            C(_match_arm_value_2):
+                connect enum_out, {|A: Reset, B: AsyncReset, C: UInt<1>|}(C, _match_arm_value_2) @[module-XXXXXXXXXX.rs 16:1]
+",
+    };
+    let m = fayalite::module::transform::deduce_resets::deduce_resets(
+        m.canonical().intern_sized(),
+        false,
+    )
+    .unwrap();
+    dbg!(m);
+    #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
+    assert_export_firrtl! {
+        m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
+        "/test/check_deduce_resets.fir": r"FIRRTL version 3.2.0
+circuit check_deduce_resets:
+    type Ty0 = {clk: Clock, rst: UInt<1>}
+    type Ty1 = {|A: UInt<1>, B: AsyncReset, C: UInt<1>|}
+    module check_deduce_resets: @[module-XXXXXXXXXX.rs 1:1]
+        input cd: Ty0 @[module-XXXXXXXXXX.rs 2:1]
+        input u8_in: UInt<8> @[module-XXXXXXXXXX.rs 4:1]
+        output u8_out: UInt<8> @[module-XXXXXXXXXX.rs 6:1]
+        input enum_in: Ty1 @[module-XXXXXXXXXX.rs 8:1]
+        output enum_out: Ty1 @[module-XXXXXXXXXX.rs 9:1]
+        output reset_out: UInt<1> @[module-XXXXXXXXXX.rs 10:1]
+        regreset my_reg: UInt<8>, cd.clk, cd.rst, UInt<8>(0h0) @[module-XXXXXXXXXX.rs 3:1]
+        connect my_reg, u8_in @[module-XXXXXXXXXX.rs 5:1]
+        connect u8_out, my_reg @[module-XXXXXXXXXX.rs 7:1]
+        connect reset_out, cd.rst @[module-XXXXXXXXXX.rs 11:1]
+        match enum_in: @[module-XXXXXXXXXX.rs 12:1]
+            A(_match_arm_value):
+                connect enum_out, {|A: UInt<1>, B: AsyncReset, C: UInt<1>|}(A, cd.rst) @[module-XXXXXXXXXX.rs 13:1]
+                connect reset_out, _match_arm_value @[module-XXXXXXXXXX.rs 14:1]
+            B(_match_arm_value_1):
+                connect enum_out, {|A: UInt<1>, B: AsyncReset, C: UInt<1>|}(B, _match_arm_value_1) @[module-XXXXXXXXXX.rs 15:1]
+            C(_match_arm_value_2):
+                connect enum_out, {|A: UInt<1>, B: AsyncReset, C: UInt<1>|}(C, _match_arm_value_2) @[module-XXXXXXXXXX.rs 16:1]
+",
+    };
+    let m = check_deduce_resets(AsyncReset);
+    dbg!(m);
+    #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
+    assert_export_firrtl! {
+        m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
+        "/test/check_deduce_resets.fir": r"FIRRTL version 3.2.0
+circuit check_deduce_resets:
+    type Ty0 = {clk: Clock, rst: AsyncReset}
+    type Ty1 = {|A: Reset, B: AsyncReset, C: UInt<1>|}
+    module check_deduce_resets: @[module-XXXXXXXXXX.rs 1:1]
+        input cd: Ty0 @[module-XXXXXXXXXX.rs 2:1]
+        input u8_in: UInt<8> @[module-XXXXXXXXXX.rs 4:1]
+        output u8_out: UInt<8> @[module-XXXXXXXXXX.rs 6:1]
+        input enum_in: Ty1 @[module-XXXXXXXXXX.rs 8:1]
+        output enum_out: Ty1 @[module-XXXXXXXXXX.rs 9:1]
+        output reset_out: Reset @[module-XXXXXXXXXX.rs 10:1]
+        regreset my_reg: UInt<8>, cd.clk, cd.rst, UInt<8>(0h0) @[module-XXXXXXXXXX.rs 3:1]
+        connect my_reg, u8_in @[module-XXXXXXXXXX.rs 5:1]
+        connect u8_out, my_reg @[module-XXXXXXXXXX.rs 7:1]
+        connect reset_out, cd.rst @[module-XXXXXXXXXX.rs 11:1]
+        match enum_in: @[module-XXXXXXXXXX.rs 12:1]
+            A(_match_arm_value):
+                connect enum_out, {|A: Reset, B: AsyncReset, C: UInt<1>|}(A, cd.rst) @[module-XXXXXXXXXX.rs 13:1]
+                connect reset_out, _match_arm_value @[module-XXXXXXXXXX.rs 14:1]
+            B(_match_arm_value_1):
+                connect enum_out, {|A: Reset, B: AsyncReset, C: UInt<1>|}(B, _match_arm_value_1) @[module-XXXXXXXXXX.rs 15:1]
+            C(_match_arm_value_2):
+                connect enum_out, {|A: Reset, B: AsyncReset, C: UInt<1>|}(C, _match_arm_value_2) @[module-XXXXXXXXXX.rs 16:1]
+",
+    };
+    let m = fayalite::module::transform::deduce_resets::deduce_resets(
+        m.canonical().intern_sized(),
+        false,
+    )
+    .unwrap();
+    dbg!(m);
+    #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
+    assert_export_firrtl! {
+        m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
+        "/test/check_deduce_resets.fir": r"FIRRTL version 3.2.0
+circuit check_deduce_resets:
+    type Ty0 = {clk: Clock, rst: AsyncReset}
+    type Ty1 = {|A: AsyncReset, B: AsyncReset, C: UInt<1>|}
+    module check_deduce_resets: @[module-XXXXXXXXXX.rs 1:1]
+        input cd: Ty0 @[module-XXXXXXXXXX.rs 2:1]
+        input u8_in: UInt<8> @[module-XXXXXXXXXX.rs 4:1]
+        output u8_out: UInt<8> @[module-XXXXXXXXXX.rs 6:1]
+        input enum_in: Ty1 @[module-XXXXXXXXXX.rs 8:1]
+        output enum_out: Ty1 @[module-XXXXXXXXXX.rs 9:1]
+        output reset_out: AsyncReset @[module-XXXXXXXXXX.rs 10:1]
+        regreset my_reg: UInt<8>, cd.clk, cd.rst, UInt<8>(0h0) @[module-XXXXXXXXXX.rs 3:1]
+        connect my_reg, u8_in @[module-XXXXXXXXXX.rs 5:1]
+        connect u8_out, my_reg @[module-XXXXXXXXXX.rs 7:1]
+        connect reset_out, cd.rst @[module-XXXXXXXXXX.rs 11:1]
+        match enum_in: @[module-XXXXXXXXXX.rs 12:1]
+            A(_match_arm_value):
+                connect enum_out, {|A: AsyncReset, B: AsyncReset, C: UInt<1>|}(A, cd.rst) @[module-XXXXXXXXXX.rs 13:1]
+                connect reset_out, _match_arm_value @[module-XXXXXXXXXX.rs 14:1]
+            B(_match_arm_value_1):
+                connect enum_out, {|A: AsyncReset, B: AsyncReset, C: UInt<1>|}(B, _match_arm_value_1) @[module-XXXXXXXXXX.rs 15:1]
+            C(_match_arm_value_2):
+                connect enum_out, {|A: AsyncReset, B: AsyncReset, C: UInt<1>|}(C, _match_arm_value_2) @[module-XXXXXXXXXX.rs 16:1]
+",
+    };
+}
+
+// intentionally not outline_generated to ensure we get correct macro hygiene
+#[hdl_module]
+pub fn check_cfgs<#[cfg(cfg_false_for_tests)] A: Type, #[cfg(cfg_true_for_tests)] B: Type>(
+    #[cfg(cfg_false_for_tests)] a: A,
+    #[cfg(cfg_true_for_tests)] b: B,
+) {
+    #[hdl]
+    struct S<#[cfg(cfg_false_for_tests)] A, #[cfg(cfg_true_for_tests)] B> {
+        #[cfg(cfg_false_for_tests)]
+        a: A,
+        #[cfg(cfg_true_for_tests)]
+        b: B,
+    }
+    #[hdl]
+    #[cfg(cfg_false_for_tests)]
+    let i_a: A = m.input(a);
+    #[hdl]
+    #[cfg(cfg_true_for_tests)]
+    let i_b: B = m.input(b);
+    #[hdl]
+    let w: S<UInt<8>> = wire();
+    #[cfg(cfg_false_for_tests)]
+    {
+        #[hdl]
+        let o_a: A = m.output(a);
+        connect(o_a, w.a.cast_bits_to(a));
+        connect_any(w.a, i_a.cast_to_bits());
+    }
+    #[cfg(cfg_true_for_tests)]
+    {
+        #[hdl]
+        let o_b: B = m.output(b);
+        connect(o_b, w.b.cast_bits_to(b));
+        connect_any(w.b, i_b.cast_to_bits());
+    }
+}
+
+#[test]
+fn test_cfgs() {
+    let _n = SourceLocation::normalize_files_for_tests();
+    let m = check_cfgs(UInt[8]);
+    dbg!(m);
+    #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
+    assert_export_firrtl! {
+        m =>
+        "/test/check_cfgs.fir": r"FIRRTL version 3.2.0
+circuit check_cfgs:
+    type Ty0 = {b: UInt<8>}
+    module check_cfgs: @[the_test_file.rs 9962:1]
+        input i_b: UInt<8> @[the_test_file.rs 9979:20]
+        output o_b: UInt<8> @[the_test_file.rs 9992:24]
+        wire w: Ty0 @[the_test_file.rs 9981:25]
+        connect o_b, w.b @[the_test_file.rs 9993:9]
+        connect w.b, i_b @[the_test_file.rs 9994:9]
+",
+    };
+}
+
+#[hdl_module(outline_generated)]
+pub fn check_let_patterns() {
+    #[hdl]
+    let tuple_in: (UInt<1>, SInt<1>, Bool) = m.input();
+    #[hdl]
+    let (tuple_0, tuple_1, tuple_2) = tuple_in;
+    #[hdl]
+    let tuple_0_out: UInt<1> = m.output();
+    connect(tuple_0_out, tuple_0);
+    #[hdl]
+    let tuple_1_out: SInt<1> = m.output();
+    connect(tuple_1_out, tuple_1);
+    #[hdl]
+    let tuple_2_out: Bool = m.output();
+    connect(tuple_2_out, tuple_2);
+
+    #[hdl]
+    let test_struct_in: TestStruct<SInt<8>> = m.input();
+    #[hdl]
+    let TestStruct::<_> { a, b } = test_struct_in;
+    #[hdl]
+    let test_struct_a_out: SInt<8> = m.output();
+    connect(test_struct_a_out, a);
+    #[hdl]
+    let test_struct_b_out: UInt<8> = m.output();
+    connect(test_struct_b_out, b);
+
+    #[hdl]
+    let test_struct_2_in: TestStruct2 = m.input();
+    #[hdl]
+    let TestStruct2 { v } = test_struct_2_in;
+    #[hdl]
+    let test_struct_2_v_out: UInt<8> = m.output();
+    connect(test_struct_2_v_out, v);
+
+    #[hdl]
+    let test_struct_3_in: TestStruct3 = m.input();
+    #[hdl]
+    let TestStruct3 {} = test_struct_3_in;
+}
+
+#[test]
+fn test_let_patterns() {
+    let _n = SourceLocation::normalize_files_for_tests();
+    let m = check_let_patterns();
+    dbg!(m);
+    #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
+    assert_export_firrtl! {
+        m =>
+        "/test/check_let_patterns.fir": r"FIRRTL version 3.2.0
+circuit check_let_patterns:
+    type Ty0 = {`0`: UInt<1>, `1`: SInt<1>, `2`: UInt<1>}
+    type Ty1 = {a: SInt<8>, b: UInt<8>}
+    type Ty2 = {v: UInt<8>}
+    type Ty3 = {}
+    module check_let_patterns: @[module-XXXXXXXXXX.rs 1:1]
+        input tuple_in: Ty0 @[module-XXXXXXXXXX.rs 2:1]
+        output tuple_0_out: UInt<1> @[module-XXXXXXXXXX.rs 4:1]
+        output tuple_1_out: SInt<1> @[module-XXXXXXXXXX.rs 6:1]
+        output tuple_2_out: UInt<1> @[module-XXXXXXXXXX.rs 8:1]
+        input test_struct_in: Ty1 @[module-XXXXXXXXXX.rs 10:1]
+        output test_struct_a_out: SInt<8> @[module-XXXXXXXXXX.rs 12:1]
+        output test_struct_b_out: UInt<8> @[module-XXXXXXXXXX.rs 14:1]
+        input test_struct_2_in: Ty2 @[module-XXXXXXXXXX.rs 16:1]
+        output test_struct_2_v_out: UInt<8> @[module-XXXXXXXXXX.rs 18:1]
+        input test_struct_3_in: Ty3 @[module-XXXXXXXXXX.rs 20:1]
+        connect tuple_0_out, tuple_in.`0` @[module-XXXXXXXXXX.rs 5:1]
+        connect tuple_1_out, tuple_in.`1` @[module-XXXXXXXXXX.rs 7:1]
+        connect tuple_2_out, tuple_in.`2` @[module-XXXXXXXXXX.rs 9:1]
+        connect test_struct_a_out, test_struct_in.a @[module-XXXXXXXXXX.rs 13:1]
+        connect test_struct_b_out, test_struct_in.b @[module-XXXXXXXXXX.rs 15:1]
+        connect test_struct_2_v_out, test_struct_2_in.v @[module-XXXXXXXXXX.rs 19:1]
+",
+    };
+}
+
+#[hdl_module(outline_generated)]
+pub fn check_struct_cmp_eq() {
+    #[hdl]
+    let tuple_lhs: (UInt<1>, SInt<1>, Bool) = m.input();
+    #[hdl]
+    let tuple_rhs: (UInt<1>, SInt<1>, Bool) = m.input();
+    #[hdl]
+    let tuple_cmp_eq: Bool = m.output();
+    connect(tuple_cmp_eq, tuple_lhs.cmp_eq(tuple_rhs));
+    #[hdl]
+    let tuple_cmp_ne: Bool = m.output();
+    connect(tuple_cmp_ne, tuple_lhs.cmp_ne(tuple_rhs));
+
+    #[hdl]
+    let test_struct_lhs: TestStruct<SInt<8>> = m.input();
+    #[hdl]
+    let test_struct_rhs: TestStruct<SInt<8>> = m.input();
+    #[hdl]
+    let test_struct_cmp_eq: Bool = m.output();
+    connect(test_struct_cmp_eq, test_struct_lhs.cmp_eq(test_struct_rhs));
+    #[hdl]
+    let test_struct_cmp_ne: Bool = m.output();
+    connect(test_struct_cmp_ne, test_struct_lhs.cmp_ne(test_struct_rhs));
+
+    #[hdl]
+    let test_struct_2_lhs: TestStruct2 = m.input();
+    #[hdl]
+    let test_struct_2_rhs: TestStruct2 = m.input();
+    #[hdl]
+    let test_struct_2_cmp_eq: Bool = m.output();
+    connect(
+        test_struct_2_cmp_eq,
+        test_struct_2_lhs.cmp_eq(test_struct_2_rhs),
+    );
+    #[hdl]
+    let test_struct_2_cmp_ne: Bool = m.output();
+    connect(
+        test_struct_2_cmp_ne,
+        test_struct_2_lhs.cmp_ne(test_struct_2_rhs),
+    );
+
+    #[hdl]
+    let test_struct_3_lhs: TestStruct3 = m.input();
+    #[hdl]
+    let test_struct_3_rhs: TestStruct3 = m.input();
+    #[hdl]
+    let test_struct_3_cmp_eq: Bool = m.output();
+    connect(
+        test_struct_3_cmp_eq,
+        test_struct_3_lhs.cmp_eq(test_struct_3_rhs),
+    );
+    #[hdl]
+    let test_struct_3_cmp_ne: Bool = m.output();
+    connect(
+        test_struct_3_cmp_ne,
+        test_struct_3_lhs.cmp_ne(test_struct_3_rhs),
+    );
+}
+
+#[test]
+fn test_struct_cmp_eq() {
+    let _n = SourceLocation::normalize_files_for_tests();
+    let m = check_struct_cmp_eq();
+    dbg!(m);
+    #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
+    assert_export_firrtl! {
+        m =>
+        "/test/check_struct_cmp_eq.fir": r"FIRRTL version 3.2.0
+circuit check_struct_cmp_eq:
+    type Ty0 = {`0`: UInt<1>, `1`: SInt<1>, `2`: UInt<1>}
+    type Ty1 = {a: SInt<8>, b: UInt<8>}
+    type Ty2 = {v: UInt<8>}
+    type Ty3 = {}
+    module check_struct_cmp_eq: @[module-XXXXXXXXXX.rs 1:1]
+        input tuple_lhs: Ty0 @[module-XXXXXXXXXX.rs 2:1]
+        input tuple_rhs: Ty0 @[module-XXXXXXXXXX.rs 3:1]
+        output tuple_cmp_eq: UInt<1> @[module-XXXXXXXXXX.rs 4:1]
+        output tuple_cmp_ne: UInt<1> @[module-XXXXXXXXXX.rs 6:1]
+        input test_struct_lhs: Ty1 @[module-XXXXXXXXXX.rs 8:1]
+        input test_struct_rhs: Ty1 @[module-XXXXXXXXXX.rs 9:1]
+        output test_struct_cmp_eq: UInt<1> @[module-XXXXXXXXXX.rs 10:1]
+        output test_struct_cmp_ne: UInt<1> @[module-XXXXXXXXXX.rs 12:1]
+        input test_struct_2_lhs: Ty2 @[module-XXXXXXXXXX.rs 14:1]
+        input test_struct_2_rhs: Ty2 @[module-XXXXXXXXXX.rs 15:1]
+        output test_struct_2_cmp_eq: UInt<1> @[module-XXXXXXXXXX.rs 16:1]
+        output test_struct_2_cmp_ne: UInt<1> @[module-XXXXXXXXXX.rs 18:1]
+        input test_struct_3_lhs: Ty3 @[module-XXXXXXXXXX.rs 20:1]
+        input test_struct_3_rhs: Ty3 @[module-XXXXXXXXXX.rs 21:1]
+        output test_struct_3_cmp_eq: UInt<1> @[module-XXXXXXXXXX.rs 22:1]
+        output test_struct_3_cmp_ne: UInt<1> @[module-XXXXXXXXXX.rs 24:1]
+        wire _array_literal_expr: UInt<1>[3]
+        connect _array_literal_expr[0], eq(tuple_lhs.`0`, tuple_rhs.`0`)
+        connect _array_literal_expr[1], eq(tuple_lhs.`1`, tuple_rhs.`1`)
+        connect _array_literal_expr[2], eq(tuple_lhs.`2`, tuple_rhs.`2`)
+        wire _cast_array_to_bits_expr: UInt<1>[3]
+        connect _cast_array_to_bits_expr[0], _array_literal_expr[0]
+        connect _cast_array_to_bits_expr[1], _array_literal_expr[1]
+        connect _cast_array_to_bits_expr[2], _array_literal_expr[2]
+        wire _cast_to_bits_expr: UInt<3>
+        connect _cast_to_bits_expr, cat(_cast_array_to_bits_expr[2], cat(_cast_array_to_bits_expr[1], _cast_array_to_bits_expr[0]))
+        connect tuple_cmp_eq, andr(_cast_to_bits_expr) @[module-XXXXXXXXXX.rs 5:1]
+        wire _array_literal_expr_1: UInt<1>[3]
+        connect _array_literal_expr_1[0], neq(tuple_lhs.`0`, tuple_rhs.`0`)
+        connect _array_literal_expr_1[1], neq(tuple_lhs.`1`, tuple_rhs.`1`)
+        connect _array_literal_expr_1[2], neq(tuple_lhs.`2`, tuple_rhs.`2`)
+        wire _cast_array_to_bits_expr_1: UInt<1>[3]
+        connect _cast_array_to_bits_expr_1[0], _array_literal_expr_1[0]
+        connect _cast_array_to_bits_expr_1[1], _array_literal_expr_1[1]
+        connect _cast_array_to_bits_expr_1[2], _array_literal_expr_1[2]
+        wire _cast_to_bits_expr_1: UInt<3>
+        connect _cast_to_bits_expr_1, cat(_cast_array_to_bits_expr_1[2], cat(_cast_array_to_bits_expr_1[1], _cast_array_to_bits_expr_1[0]))
+        connect tuple_cmp_ne, orr(_cast_to_bits_expr_1) @[module-XXXXXXXXXX.rs 7:1]
+        connect test_struct_cmp_eq, and(eq(test_struct_lhs.a, test_struct_rhs.a), eq(test_struct_lhs.b, test_struct_rhs.b)) @[module-XXXXXXXXXX.rs 11:1]
+        connect test_struct_cmp_ne, or(neq(test_struct_lhs.a, test_struct_rhs.a), neq(test_struct_lhs.b, test_struct_rhs.b)) @[module-XXXXXXXXXX.rs 13:1]
+        connect test_struct_2_cmp_eq, eq(test_struct_2_lhs.v, test_struct_2_rhs.v) @[module-XXXXXXXXXX.rs 17:1]
+        connect test_struct_2_cmp_ne, neq(test_struct_2_lhs.v, test_struct_2_rhs.v) @[module-XXXXXXXXXX.rs 19:1]
+        connect test_struct_3_cmp_eq, UInt<1>(0h1) @[module-XXXXXXXXXX.rs 23:1]
+        connect test_struct_3_cmp_ne, UInt<1>(0h0) @[module-XXXXXXXXXX.rs 25:1]
+",
+    };
+}

crates/fayalite/tests/sim/expected/array_rw.vcd

@@ -0,0 +1,283 @@
+$timescale 1 ps $end
+$scope module array_rw $end
+$scope struct array_in $end
+$var wire 8 ! \[0] $end
+$var wire 8 " \[1] $end
+$var wire 8 # \[2] $end
+$var wire 8 $ \[3] $end
+$var wire 8 % \[4] $end
+$var wire 8 & \[5] $end
+$var wire 8 ' \[6] $end
+$var wire 8 ( \[7] $end
+$var wire 8 ) \[8] $end
+$var wire 8 * \[9] $end
+$var wire 8 + \[10] $end
+$var wire 8 , \[11] $end
+$var wire 8 - \[12] $end
+$var wire 8 . \[13] $end
+$var wire 8 / \[14] $end
+$var wire 8 0 \[15] $end
+$upscope $end
+$scope struct array_out $end
+$var wire 8 1 \[0] $end
+$var wire 8 2 \[1] $end
+$var wire 8 3 \[2] $end
+$var wire 8 4 \[3] $end
+$var wire 8 5 \[4] $end
+$var wire 8 6 \[5] $end
+$var wire 8 7 \[6] $end
+$var wire 8 8 \[7] $end
+$var wire 8 9 \[8] $end
+$var wire 8 : \[9] $end
+$var wire 8 ; \[10] $end
+$var wire 8 < \[11] $end
+$var wire 8 = \[12] $end
+$var wire 8 > \[13] $end
+$var wire 8 ? \[14] $end
+$var wire 8 @ \[15] $end
+$upscope $end
+$var wire 8 A read_index $end
+$var wire 8 B read_data $end
+$var wire 8 C write_index $end
+$var wire 8 D write_data $end
+$var wire 1 E write_en $end
+$scope struct array_wire $end
+$var wire 8 F \[0] $end
+$var wire 8 G \[1] $end
+$var wire 8 H \[2] $end
+$var wire 8 I \[3] $end
+$var wire 8 J \[4] $end
+$var wire 8 K \[5] $end
+$var wire 8 L \[6] $end
+$var wire 8 M \[7] $end
+$var wire 8 N \[8] $end
+$var wire 8 O \[9] $end
+$var wire 8 P \[10] $end
+$var wire 8 Q \[11] $end
+$var wire 8 R \[12] $end
+$var wire 8 S \[13] $end
+$var wire 8 T \[14] $end
+$var wire 8 U \[15] $end
+$upscope $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+b11111111 !
+b1111111 "
+b111111 #
+b11111 $
+b1111 %
+b111 &
+b11 '
+b1 (
+b0 )
+b10000000 *
+b11000000 +
+b11100000 ,
+b11110000 -
+b11111000 .
+b11111100 /
+b11111110 0
+b11111111 1
+b1111111 2
+b111111 3
+b11111 4
+b1111 5
+b111 6
+b11 7
+b1 8
+b0 9
+b10000000 :
+b11000000 ;
+b11100000 <
+b11110000 =
+b11111000 >
+b11111100 ?
+b11111110 @
+b0 A
+b11111111 B
+b0 C
+b0 D
+0E
+b11111111 F
+b1111111 G
+b111111 H
+b11111 I
+b1111 J
+b111 K
+b11 L
+b1 M
+b0 N
+b10000000 O
+b11000000 P
+b11100000 Q
+b11110000 R
+b11111000 S
+b11111100 T
+b11111110 U
+$end
+#1000000
+b1 A
+b1111111 B
+#2000000
+b10 A
+b111111 B
+#3000000
+b11 A
+b11111 B
+#4000000
+b100 A
+b1111 B
+#5000000
+b101 A
+b111 B
+#6000000
+b110 A
+b11 B
+#7000000
+b111 A
+b1 B
+#8000000
+b1000 A
+b0 B
+#9000000
+b1001 A
+b10000000 B
+#10000000
+b1010 A
+b11000000 B
+#11000000
+b1011 A
+b11100000 B
+#12000000
+b1100 A
+b11110000 B
+#13000000
+b1101 A
+b11111000 B
+#14000000
+b1110 A
+b11111100 B
+#15000000
+b1111 A
+b11111110 B
+#16000000
+b10000 A
+b0 B
+#17000000
+b0 1
+b0 A
+1E
+b0 F
+#18000000
+b11111111 1
+b1 2
+b11111111 B
+b1 C
+b1 D
+b11111111 F
+b1 G
+#19000000
+b1111111 2
+b100 3
+b10 C
+b100 D
+b1111111 G
+b100 H
+#20000000
+b111111 3
+b1001 4
+b11 C
+b1001 D
+b111111 H
+b1001 I
+#21000000
+b11111 4
+b10000 5
+b100 C
+b10000 D
+b11111 I
+b10000 J
+#22000000
+b1111 5
+b11001 6
+b101 C
+b11001 D
+b1111 J
+b11001 K
+#23000000
+b111 6
+b100100 7
+b110 C
+b100100 D
+b111 K
+b100100 L
+#24000000
+b11 7
+b110001 8
+b111 C
+b110001 D
+b11 L
+b110001 M
+#25000000
+b1 8
+b1000000 9
+b1000 C
+b1000000 D
+b1 M
+b1000000 N
+#26000000
+b0 9
+b1010001 :
+b1001 C
+b1010001 D
+b0 N
+b1010001 O
+#27000000
+b10000000 :
+b1100100 ;
+b1010 C
+b1100100 D
+b10000000 O
+b1100100 P
+#28000000
+b11000000 ;
+b1111001 <
+b1011 C
+b1111001 D
+b11000000 P
+b1111001 Q
+#29000000
+b11100000 <
+b10010000 =
+b1100 C
+b10010000 D
+b11100000 Q
+b10010000 R
+#30000000
+b11110000 =
+b10101001 >
+b1101 C
+b10101001 D
+b11110000 R
+b10101001 S
+#31000000
+b11111000 >
+b11000100 ?
+b1110 C
+b11000100 D
+b11111000 S
+b11000100 T
+#32000000
+b11111100 ?
+b11100001 @
+b1111 C
+b11100001 D
+b11111100 T
+b11100001 U
+#33000000
+b11111110 @
+b10000 C
+b0 D
+b11111110 U
+#34000000

crates/fayalite/tests/sim/expected/conditional_assignment_last.txt

@@ -0,0 +1,189 @@
+Simulation {
+    state: State {
+        insns: Insns {
+            state_layout: StateLayout {
+                ty: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 4,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(conditional_assignment_last: conditional_assignment_last).conditional_assignment_last::i",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(conditional_assignment_last: conditional_assignment_last).conditional_assignment_last::w",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                memories: StatePartLayout<Memories> {
+                    len: 0,
+                    debug_data: [],
+                    layout_data: [],
+                    ..
+                },
+            },
+            insns: [
+                // at: module-XXXXXXXXXX.rs:1:1
+                0: Const {
+                    dest: StatePartIndex<BigSlots>(3), // (0x0) SlotDebugData { name: "", ty: Bool },
+                    value: 0x0,
+                },
+                1: Const {
+                    dest: StatePartIndex<BigSlots>(2), // (0x1) SlotDebugData { name: "", ty: Bool },
+                    value: 0x1,
+                },
+                // at: module-XXXXXXXXXX.rs:4:1
+                2: Copy {
+                    dest: StatePartIndex<BigSlots>(1), // (0x0) SlotDebugData { name: "InstantiatedModule(conditional_assignment_last: conditional_assignment_last).conditional_assignment_last::w", ty: Bool },
+                    src: StatePartIndex<BigSlots>(2), // (0x1) SlotDebugData { name: "", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:5:1
+                3: BranchIfZero {
+                    target: 5,
+                    value: StatePartIndex<BigSlots>(0), // (0x1) SlotDebugData { name: "InstantiatedModule(conditional_assignment_last: conditional_assignment_last).conditional_assignment_last::i", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:6:1
+                4: Copy {
+                    dest: StatePartIndex<BigSlots>(1), // (0x0) SlotDebugData { name: "InstantiatedModule(conditional_assignment_last: conditional_assignment_last).conditional_assignment_last::w", ty: Bool },
+                    src: StatePartIndex<BigSlots>(3), // (0x0) SlotDebugData { name: "", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                5: Return,
+            ],
+            ..
+        },
+        pc: 5,
+        memory_write_log: [],
+        memories: StatePart {
+            value: [],
+        },
+        small_slots: StatePart {
+            value: [],
+        },
+        big_slots: StatePart {
+            value: [
+                1,
+                0,
+                1,
+                0,
+            ],
+        },
+    },
+    io: Instance {
+        name: <simulator>::conditional_assignment_last,
+        instantiated: Module {
+            name: conditional_assignment_last,
+            ..
+        },
+    },
+    uninitialized_inputs: {},
+    io_targets: {
+        Instance {
+            name: <simulator>::conditional_assignment_last,
+            instantiated: Module {
+                name: conditional_assignment_last,
+                ..
+            },
+        }.i: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: Bool,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(conditional_assignment_last: conditional_assignment_last).conditional_assignment_last::i",
+                                ty: Bool,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 0, len: 1 },
+            },
+            write: None,
+        },
+    },
+    made_initial_step: true,
+    needs_settle: false,
+    trace_decls: TraceModule {
+        name: "conditional_assignment_last",
+        children: [
+            TraceModuleIO {
+                name: "i",
+                child: TraceBool {
+                    location: TraceScalarId(0),
+                    name: "i",
+                    flow: Source,
+                },
+                ty: Bool,
+                flow: Source,
+            },
+            TraceWire {
+                name: "w",
+                child: TraceBool {
+                    location: TraceScalarId(1),
+                    name: "w",
+                    flow: Duplex,
+                },
+                ty: Bool,
+            },
+        ],
+    },
+    traces: [
+        SimTrace {
+            id: TraceScalarId(0),
+            kind: BigBool {
+                index: StatePartIndex<BigSlots>(0),
+            },
+            state: 0x1,
+            last_state: 0x0,
+        },
+        SimTrace {
+            id: TraceScalarId(1),
+            kind: BigBool {
+                index: StatePartIndex<BigSlots>(1),
+            },
+            state: 0x0,
+            last_state: 0x1,
+        },
+    ],
+    trace_memories: {},
+    trace_writers: [
+        Running(
+            VcdWriter {
+                finished_init: true,
+                timescale: 1 ps,
+                ..
+            },
+        ),
+    ],
+    instant: 2 μs,
+    clocks_triggered: [],
+    ..
+}

crates/fayalite/tests/sim/expected/conditional_assignment_last.vcd

@@ -0,0 +1,14 @@
+$timescale 1 ps $end
+$scope module conditional_assignment_last $end
+$var wire 1 ! i $end
+$var wire 1 " w $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+0!
+1"
+$end
+#1000000
+1!
+0"
+#2000000

crates/fayalite/tests/sim/expected/connect_const.txt

@@ -0,0 +1,142 @@
+Simulation {
+    state: State {
+        insns: Insns {
+            state_layout: StateLayout {
+                ty: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 2,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(connect_const: connect_const).connect_const::o",
+                                ty: UInt<8>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<8>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                memories: StatePartLayout<Memories> {
+                    len: 0,
+                    debug_data: [],
+                    layout_data: [],
+                    ..
+                },
+            },
+            insns: [
+                // at: module-XXXXXXXXXX.rs:1:1
+                0: Const {
+                    dest: StatePartIndex<BigSlots>(1), // (0x5) SlotDebugData { name: "", ty: UInt<8> },
+                    value: 0x5,
+                },
+                // at: module-XXXXXXXXXX.rs:3:1
+                1: Copy {
+                    dest: StatePartIndex<BigSlots>(0), // (0x5) SlotDebugData { name: "InstantiatedModule(connect_const: connect_const).connect_const::o", ty: UInt<8> },
+                    src: StatePartIndex<BigSlots>(1), // (0x5) SlotDebugData { name: "", ty: UInt<8> },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                2: Return,
+            ],
+            ..
+        },
+        pc: 2,
+        memory_write_log: [],
+        memories: StatePart {
+            value: [],
+        },
+        small_slots: StatePart {
+            value: [],
+        },
+        big_slots: StatePart {
+            value: [
+                5,
+                5,
+            ],
+        },
+    },
+    io: Instance {
+        name: <simulator>::connect_const,
+        instantiated: Module {
+            name: connect_const,
+            ..
+        },
+    },
+    uninitialized_inputs: {},
+    io_targets: {
+        Instance {
+            name: <simulator>::connect_const,
+            instantiated: Module {
+                name: connect_const,
+                ..
+            },
+        }.o: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: UInt<8>,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(connect_const: connect_const).connect_const::o",
+                                ty: UInt<8>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 0, len: 1 },
+            },
+            write: None,
+        },
+    },
+    made_initial_step: true,
+    needs_settle: false,
+    trace_decls: TraceModule {
+        name: "connect_const",
+        children: [
+            TraceModuleIO {
+                name: "o",
+                child: TraceUInt {
+                    location: TraceScalarId(0),
+                    name: "o",
+                    ty: UInt<8>,
+                    flow: Sink,
+                },
+                ty: UInt<8>,
+                flow: Sink,
+            },
+        ],
+    },
+    traces: [
+        SimTrace {
+            id: TraceScalarId(0),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(0),
+                ty: UInt<8>,
+            },
+            state: 0x05,
+            last_state: 0x05,
+        },
+    ],
+    trace_memories: {},
+    trace_writers: [],
+    instant: 0 s,
+    clocks_triggered: [],
+    ..
+}

crates/fayalite/tests/sim/expected/connect_const_reset.txt

@@ -0,0 +1,229 @@
+Simulation {
+    state: State {
+        insns: Insns {
+            state_layout: StateLayout {
+                ty: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 5,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(connect_const_reset: connect_const_reset).connect_const_reset::reset_out",
+                                ty: AsyncReset,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(connect_const_reset: connect_const_reset).connect_const_reset::bit_out",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: AsyncReset,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                memories: StatePartLayout<Memories> {
+                    len: 0,
+                    debug_data: [],
+                    layout_data: [],
+                    ..
+                },
+            },
+            insns: [
+                // at: module-XXXXXXXXXX.rs:1:1
+                0: Const {
+                    dest: StatePartIndex<BigSlots>(2), // (0x1) SlotDebugData { name: "", ty: Bool },
+                    value: 0x1,
+                },
+                1: Copy {
+                    dest: StatePartIndex<BigSlots>(3), // (0x1) SlotDebugData { name: "", ty: AsyncReset },
+                    src: StatePartIndex<BigSlots>(2), // (0x1) SlotDebugData { name: "", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:4:1
+                2: Copy {
+                    dest: StatePartIndex<BigSlots>(0), // (0x1) SlotDebugData { name: "InstantiatedModule(connect_const_reset: connect_const_reset).connect_const_reset::reset_out", ty: AsyncReset },
+                    src: StatePartIndex<BigSlots>(3), // (0x1) SlotDebugData { name: "", ty: AsyncReset },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                3: Copy {
+                    dest: StatePartIndex<BigSlots>(4), // (0x1) SlotDebugData { name: "", ty: Bool },
+                    src: StatePartIndex<BigSlots>(0), // (0x1) SlotDebugData { name: "InstantiatedModule(connect_const_reset: connect_const_reset).connect_const_reset::reset_out", ty: AsyncReset },
+                },
+                // at: module-XXXXXXXXXX.rs:5:1
+                4: Copy {
+                    dest: StatePartIndex<BigSlots>(1), // (0x1) SlotDebugData { name: "InstantiatedModule(connect_const_reset: connect_const_reset).connect_const_reset::bit_out", ty: Bool },
+                    src: StatePartIndex<BigSlots>(4), // (0x1) SlotDebugData { name: "", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                5: Return,
+            ],
+            ..
+        },
+        pc: 5,
+        memory_write_log: [],
+        memories: StatePart {
+            value: [],
+        },
+        small_slots: StatePart {
+            value: [],
+        },
+        big_slots: StatePart {
+            value: [
+                1,
+                1,
+                1,
+                1,
+                1,
+            ],
+        },
+    },
+    io: Instance {
+        name: <simulator>::connect_const_reset,
+        instantiated: Module {
+            name: connect_const_reset,
+            ..
+        },
+    },
+    uninitialized_inputs: {},
+    io_targets: {
+        Instance {
+            name: <simulator>::connect_const_reset,
+            instantiated: Module {
+                name: connect_const_reset,
+                ..
+            },
+        }.bit_out: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: Bool,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(connect_const_reset: connect_const_reset).connect_const_reset::bit_out",
+                                ty: Bool,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 1, len: 1 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::connect_const_reset,
+            instantiated: Module {
+                name: connect_const_reset,
+                ..
+            },
+        }.reset_out: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: AsyncReset,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(connect_const_reset: connect_const_reset).connect_const_reset::reset_out",
+                                ty: AsyncReset,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 0, len: 1 },
+            },
+            write: None,
+        },
+    },
+    made_initial_step: true,
+    needs_settle: false,
+    trace_decls: TraceModule {
+        name: "connect_const_reset",
+        children: [
+            TraceModuleIO {
+                name: "reset_out",
+                child: TraceAsyncReset {
+                    location: TraceScalarId(0),
+                    name: "reset_out",
+                    flow: Sink,
+                },
+                ty: AsyncReset,
+                flow: Sink,
+            },
+            TraceModuleIO {
+                name: "bit_out",
+                child: TraceBool {
+                    location: TraceScalarId(1),
+                    name: "bit_out",
+                    flow: Sink,
+                },
+                ty: Bool,
+                flow: Sink,
+            },
+        ],
+    },
+    traces: [
+        SimTrace {
+            id: TraceScalarId(0),
+            kind: BigAsyncReset {
+                index: StatePartIndex<BigSlots>(0),
+            },
+            state: 0x1,
+            last_state: 0x1,
+        },
+        SimTrace {
+            id: TraceScalarId(1),
+            kind: BigBool {
+                index: StatePartIndex<BigSlots>(1),
+            },
+            state: 0x1,
+            last_state: 0x1,
+        },
+    ],
+    trace_memories: {},
+    trace_writers: [
+        Running(
+            VcdWriter {
+                finished_init: true,
+                timescale: 1 ps,
+                ..
+            },
+        ),
+    ],
+    instant: 1 μs,
+    clocks_triggered: [],
+    ..
+}

crates/fayalite/tests/sim/expected/connect_const_reset.vcd

@@ -0,0 +1,11 @@
+$timescale 1 ps $end
+$scope module connect_const_reset $end
+$var wire 1 ! reset_out $end
+$var wire 1 " bit_out $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+1!
+1"
+$end
+#1000000

crates/fayalite/tests/sim/expected/counter_async.txt

@@ -0,0 +1,522 @@
+Simulation {
+    state: State {
+        insns: Insns {
+            state_layout: StateLayout {
+                ty: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 4,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                        ],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 10,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::cd.clk",
+                                ty: Clock,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::cd.rst",
+                                ty: AsyncReset,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::count",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::count_reg",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::count_reg$next",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<1>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<5>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<4>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                memories: StatePartLayout<Memories> {
+                    len: 0,
+                    debug_data: [],
+                    layout_data: [],
+                    ..
+                },
+            },
+            insns: [
+                // at: module-XXXXXXXXXX.rs:1:1
+                0: Const {
+                    dest: StatePartIndex<BigSlots>(7), // (0x1) SlotDebugData { name: "", ty: UInt<1> },
+                    value: 0x1,
+                },
+                1: Copy {
+                    dest: StatePartIndex<BigSlots>(6), // (0x0) SlotDebugData { name: "", ty: Bool },
+                    src: StatePartIndex<BigSlots>(1), // (0x0) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::cd.rst", ty: AsyncReset },
+                },
+                // at: module-XXXXXXXXXX.rs:3:1
+                2: IsNonZeroDestIsSmall {
+                    dest: StatePartIndex<SmallSlots>(3), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                    src: StatePartIndex<BigSlots>(1), // (0x0) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::cd.rst", ty: AsyncReset },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                3: Const {
+                    dest: StatePartIndex<BigSlots>(5), // (0x3) SlotDebugData { name: "", ty: UInt<4> },
+                    value: 0x3,
+                },
+                // at: module-XXXXXXXXXX.rs:3:1
+                4: BranchIfZero {
+                    target: 6,
+                    value: StatePartIndex<BigSlots>(6), // (0x0) SlotDebugData { name: "", ty: Bool },
+                },
+                5: Copy {
+                    dest: StatePartIndex<BigSlots>(3), // (0x3) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(5), // (0x3) SlotDebugData { name: "", ty: UInt<4> },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                6: Add {
+                    dest: StatePartIndex<BigSlots>(8), // (0x4) SlotDebugData { name: "", ty: UInt<5> },
+                    lhs: StatePartIndex<BigSlots>(3), // (0x3) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg", ty: UInt<4> },
+                    rhs: StatePartIndex<BigSlots>(7), // (0x1) SlotDebugData { name: "", ty: UInt<1> },
+                },
+                7: CastToUInt {
+                    dest: StatePartIndex<BigSlots>(9), // (0x4) SlotDebugData { name: "", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(8), // (0x4) SlotDebugData { name: "", ty: UInt<5> },
+                    dest_width: 4,
+                },
+                // at: module-XXXXXXXXXX.rs:4:1
+                8: Copy {
+                    dest: StatePartIndex<BigSlots>(4), // (0x4) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg$next", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(9), // (0x4) SlotDebugData { name: "", ty: UInt<4> },
+                },
+                // at: module-XXXXXXXXXX.rs:6:1
+                9: Copy {
+                    dest: StatePartIndex<BigSlots>(2), // (0x3) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(3), // (0x3) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg", ty: UInt<4> },
+                },
+                // at: module-XXXXXXXXXX.rs:3:1
+                10: IsNonZeroDestIsSmall {
+                    dest: StatePartIndex<SmallSlots>(2), // (0x1 1) SlotDebugData { name: "", ty: Bool },
+                    src: StatePartIndex<BigSlots>(0), // (0x1) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::cd.clk", ty: Clock },
+                },
+                11: AndSmall {
+                    dest: StatePartIndex<SmallSlots>(1), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                    lhs: StatePartIndex<SmallSlots>(2), // (0x1 1) SlotDebugData { name: "", ty: Bool },
+                    rhs: StatePartIndex<SmallSlots>(0), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                12: BranchIfSmallNonZero {
+                    target: 16,
+                    value: StatePartIndex<SmallSlots>(3), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                13: BranchIfSmallZero {
+                    target: 17,
+                    value: StatePartIndex<SmallSlots>(1), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                14: Copy {
+                    dest: StatePartIndex<BigSlots>(3), // (0x3) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(4), // (0x4) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg$next", ty: UInt<4> },
+                },
+                15: Branch {
+                    target: 17,
+                },
+                16: Copy {
+                    dest: StatePartIndex<BigSlots>(3), // (0x3) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(5), // (0x3) SlotDebugData { name: "", ty: UInt<4> },
+                },
+                17: XorSmallImmediate {
+                    dest: StatePartIndex<SmallSlots>(0), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                    lhs: StatePartIndex<SmallSlots>(2), // (0x1 1) SlotDebugData { name: "", ty: Bool },
+                    rhs: 0x1,
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                18: Return,
+            ],
+            ..
+        },
+        pc: 18,
+        memory_write_log: [],
+        memories: StatePart {
+            value: [],
+        },
+        small_slots: StatePart {
+            value: [
+                0,
+                0,
+                1,
+                0,
+            ],
+        },
+        big_slots: StatePart {
+            value: [
+                1,
+                0,
+                3,
+                3,
+                4,
+                3,
+                0,
+                1,
+                4,
+                4,
+            ],
+        },
+    },
+    io: Instance {
+        name: <simulator>::counter,
+        instantiated: Module {
+            name: counter,
+            ..
+        },
+    },
+    uninitialized_inputs: {},
+    io_targets: {
+        Instance {
+            name: <simulator>::counter,
+            instantiated: Module {
+                name: counter,
+                ..
+            },
+        }.cd: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: Bundle {
+                    /* offset = 0 */
+                    clk: Clock,
+                    /* offset = 1 */
+                    rst: AsyncReset,
+                },
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 2,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::cd.clk",
+                                ty: Clock,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::cd.rst",
+                                ty: AsyncReset,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Bundle {
+                    fields: [
+                        CompiledBundleField {
+                            offset: TypeIndex {
+                                small_slots: StatePartIndex<SmallSlots>(0),
+                                big_slots: StatePartIndex<BigSlots>(0),
+                            },
+                            ty: CompiledTypeLayout {
+                                ty: Clock,
+                                layout: TypeLayout {
+                                    small_slots: StatePartLayout<SmallSlots> {
+                                        len: 0,
+                                        debug_data: [],
+                                        ..
+                                    },
+                                    big_slots: StatePartLayout<BigSlots> {
+                                        len: 1,
+                                        debug_data: [
+                                            SlotDebugData {
+                                                name: "",
+                                                ty: Clock,
+                                            },
+                                        ],
+                                        ..
+                                    },
+                                },
+                                body: Scalar,
+                            },
+                        },
+                        CompiledBundleField {
+                            offset: TypeIndex {
+                                small_slots: StatePartIndex<SmallSlots>(0),
+                                big_slots: StatePartIndex<BigSlots>(1),
+                            },
+                            ty: CompiledTypeLayout {
+                                ty: AsyncReset,
+                                layout: TypeLayout {
+                                    small_slots: StatePartLayout<SmallSlots> {
+                                        len: 0,
+                                        debug_data: [],
+                                        ..
+                                    },
+                                    big_slots: StatePartLayout<BigSlots> {
+                                        len: 1,
+                                        debug_data: [
+                                            SlotDebugData {
+                                                name: "",
+                                                ty: AsyncReset,
+                                            },
+                                        ],
+                                        ..
+                                    },
+                                },
+                                body: Scalar,
+                            },
+                        },
+                    ],
+                },
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 0, len: 2 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::counter,
+            instantiated: Module {
+                name: counter,
+                ..
+            },
+        }.cd.clk: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: Clock,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: Clock,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 0, len: 1 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::counter,
+            instantiated: Module {
+                name: counter,
+                ..
+            },
+        }.cd.rst: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: AsyncReset,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: AsyncReset,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 1, len: 1 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::counter,
+            instantiated: Module {
+                name: counter,
+                ..
+            },
+        }.count: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: UInt<4>,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::count",
+                                ty: UInt<4>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 2, len: 1 },
+            },
+            write: None,
+        },
+    },
+    made_initial_step: true,
+    needs_settle: false,
+    trace_decls: TraceModule {
+        name: "counter",
+        children: [
+            TraceModuleIO {
+                name: "cd",
+                child: TraceBundle {
+                    name: "cd",
+                    fields: [
+                        TraceClock {
+                            location: TraceScalarId(0),
+                            name: "clk",
+                            flow: Source,
+                        },
+                        TraceAsyncReset {
+                            location: TraceScalarId(1),
+                            name: "rst",
+                            flow: Source,
+                        },
+                    ],
+                    ty: Bundle {
+                        /* offset = 0 */
+                        clk: Clock,
+                        /* offset = 1 */
+                        rst: AsyncReset,
+                    },
+                    flow: Source,
+                },
+                ty: Bundle {
+                    /* offset = 0 */
+                    clk: Clock,
+                    /* offset = 1 */
+                    rst: AsyncReset,
+                },
+                flow: Source,
+            },
+            TraceModuleIO {
+                name: "count",
+                child: TraceUInt {
+                    location: TraceScalarId(2),
+                    name: "count",
+                    ty: UInt<4>,
+                    flow: Sink,
+                },
+                ty: UInt<4>,
+                flow: Sink,
+            },
+            TraceReg {
+                name: "count_reg",
+                child: TraceUInt {
+                    location: TraceScalarId(3),
+                    name: "count_reg",
+                    ty: UInt<4>,
+                    flow: Duplex,
+                },
+                ty: UInt<4>,
+            },
+        ],
+    },
+    traces: [
+        SimTrace {
+            id: TraceScalarId(0),
+            kind: BigClock {
+                index: StatePartIndex<BigSlots>(0),
+            },
+            state: 0x1,
+            last_state: 0x1,
+        },
+        SimTrace {
+            id: TraceScalarId(1),
+            kind: BigAsyncReset {
+                index: StatePartIndex<BigSlots>(1),
+            },
+            state: 0x0,
+            last_state: 0x0,
+        },
+        SimTrace {
+            id: TraceScalarId(2),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(2),
+                ty: UInt<4>,
+            },
+            state: 0x3,
+            last_state: 0x2,
+        },
+        SimTrace {
+            id: TraceScalarId(3),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(3),
+                ty: UInt<4>,
+            },
+            state: 0x3,
+            last_state: 0x3,
+        },
+    ],
+    trace_memories: {},
+    trace_writers: [
+        Running(
+            VcdWriter {
+                finished_init: true,
+                timescale: 1 ps,
+                ..
+            },
+        ),
+    ],
+    instant: 66 μs,
+    clocks_triggered: [
+        StatePartIndex<SmallSlots>(1),
+    ],
+    ..
+}

crates/fayalite/tests/sim/expected/counter_async.vcd

@@ -0,0 +1,217 @@
+$timescale 1 ps $end
+$scope module counter $end
+$scope struct cd $end
+$var wire 1 ! clk $end
+$var wire 1 " rst $end
+$upscope $end
+$var wire 4 # count $end
+$var reg 4 $ count_reg $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+0!
+0"
+b0 #
+b0 $
+$end
+#500000
+1"
+b11 #
+b11 $
+#1000000
+1!
+#1500000
+0"
+#2000000
+0!
+#3000000
+1!
+b100 $
+b100 #
+#4000000
+0!
+#5000000
+1!
+b101 $
+b101 #
+#6000000
+0!
+#7000000
+1!
+b110 $
+b110 #
+#8000000
+0!
+#9000000
+1!
+b111 $
+b111 #
+#10000000
+0!
+#11000000
+1!
+b1000 $
+b1000 #
+#12000000
+0!
+#13000000
+1!
+b1001 $
+b1001 #
+#14000000
+0!
+#15000000
+1!
+b1010 $
+b1010 #
+#16000000
+0!
+#17000000
+1!
+b1011 $
+b1011 #
+#18000000
+0!
+#19000000
+1!
+b1100 $
+b1100 #
+#20000000
+0!
+#21000000
+1!
+b1101 $
+b1101 #
+#22000000
+0!
+#23000000
+1!
+b1110 $
+b1110 #
+#24000000
+0!
+#25000000
+1!
+b1111 $
+b1111 #
+#26000000
+0!
+#27000000
+1!
+b0 $
+b0 #
+#28000000
+0!
+#29000000
+1!
+b1 $
+b1 #
+#30000000
+0!
+#31000000
+1!
+b10 $
+b10 #
+#32000000
+0!
+#33000000
+1!
+b11 $
+b11 #
+#34000000
+0!
+#35000000
+1!
+b100 $
+b100 #
+#36000000
+0!
+#37000000
+1!
+b101 $
+b101 #
+#38000000
+0!
+#39000000
+1!
+b110 $
+b110 #
+#40000000
+0!
+#41000000
+1!
+b111 $
+b111 #
+#42000000
+0!
+#43000000
+1!
+b1000 $
+b1000 #
+#44000000
+0!
+#45000000
+1!
+b1001 $
+b1001 #
+#46000000
+0!
+#47000000
+1!
+b1010 $
+b1010 #
+#48000000
+0!
+#49000000
+1!
+b1011 $
+b1011 #
+#50000000
+0!
+#51000000
+1!
+b1100 $
+b1100 #
+#52000000
+0!
+#53000000
+1!
+b1101 $
+b1101 #
+#54000000
+0!
+#55000000
+1!
+b1110 $
+b1110 #
+#56000000
+0!
+#57000000
+1!
+b1111 $
+b1111 #
+#58000000
+0!
+#59000000
+1!
+b0 $
+b0 #
+#60000000
+0!
+#61000000
+1!
+b1 $
+b1 #
+#62000000
+0!
+#63000000
+1!
+b10 $
+b10 #
+#64000000
+0!
+#65000000
+1!
+b11 $
+b11 #
+#66000000

crates/fayalite/tests/sim/expected/counter_sync.txt

@@ -0,0 +1,503 @@
+Simulation {
+    state: State {
+        insns: Insns {
+            state_layout: StateLayout {
+                ty: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 4,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                        ],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 9,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::cd.clk",
+                                ty: Clock,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::cd.rst",
+                                ty: SyncReset,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::count",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::count_reg",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::count_reg$next",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<1>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<5>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<4>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                memories: StatePartLayout<Memories> {
+                    len: 0,
+                    debug_data: [],
+                    layout_data: [],
+                    ..
+                },
+            },
+            insns: [
+                // at: module-XXXXXXXXXX.rs:6:1
+                0: Copy {
+                    dest: StatePartIndex<BigSlots>(2), // (0x3) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(3), // (0x3) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg", ty: UInt<4> },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                1: Const {
+                    dest: StatePartIndex<BigSlots>(6), // (0x1) SlotDebugData { name: "", ty: UInt<1> },
+                    value: 0x1,
+                },
+                2: Add {
+                    dest: StatePartIndex<BigSlots>(7), // (0x4) SlotDebugData { name: "", ty: UInt<5> },
+                    lhs: StatePartIndex<BigSlots>(3), // (0x3) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg", ty: UInt<4> },
+                    rhs: StatePartIndex<BigSlots>(6), // (0x1) SlotDebugData { name: "", ty: UInt<1> },
+                },
+                3: CastToUInt {
+                    dest: StatePartIndex<BigSlots>(8), // (0x4) SlotDebugData { name: "", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(7), // (0x4) SlotDebugData { name: "", ty: UInt<5> },
+                    dest_width: 4,
+                },
+                // at: module-XXXXXXXXXX.rs:4:1
+                4: Copy {
+                    dest: StatePartIndex<BigSlots>(4), // (0x4) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg$next", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(8), // (0x4) SlotDebugData { name: "", ty: UInt<4> },
+                },
+                // at: module-XXXXXXXXXX.rs:3:1
+                5: IsNonZeroDestIsSmall {
+                    dest: StatePartIndex<SmallSlots>(3), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                    src: StatePartIndex<BigSlots>(1), // (0x0) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::cd.rst", ty: SyncReset },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                6: Const {
+                    dest: StatePartIndex<BigSlots>(5), // (0x3) SlotDebugData { name: "", ty: UInt<4> },
+                    value: 0x3,
+                },
+                // at: module-XXXXXXXXXX.rs:3:1
+                7: IsNonZeroDestIsSmall {
+                    dest: StatePartIndex<SmallSlots>(2), // (0x1 1) SlotDebugData { name: "", ty: Bool },
+                    src: StatePartIndex<BigSlots>(0), // (0x1) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::cd.clk", ty: Clock },
+                },
+                8: AndSmall {
+                    dest: StatePartIndex<SmallSlots>(1), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                    lhs: StatePartIndex<SmallSlots>(2), // (0x1 1) SlotDebugData { name: "", ty: Bool },
+                    rhs: StatePartIndex<SmallSlots>(0), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                9: BranchIfSmallZero {
+                    target: 14,
+                    value: StatePartIndex<SmallSlots>(1), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                10: BranchIfSmallNonZero {
+                    target: 13,
+                    value: StatePartIndex<SmallSlots>(3), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                11: Copy {
+                    dest: StatePartIndex<BigSlots>(3), // (0x3) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(4), // (0x4) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg$next", ty: UInt<4> },
+                },
+                12: Branch {
+                    target: 14,
+                },
+                13: Copy {
+                    dest: StatePartIndex<BigSlots>(3), // (0x3) SlotDebugData { name: "InstantiatedModule(counter: counter).counter::count_reg", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(5), // (0x3) SlotDebugData { name: "", ty: UInt<4> },
+                },
+                14: XorSmallImmediate {
+                    dest: StatePartIndex<SmallSlots>(0), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                    lhs: StatePartIndex<SmallSlots>(2), // (0x1 1) SlotDebugData { name: "", ty: Bool },
+                    rhs: 0x1,
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                15: Return,
+            ],
+            ..
+        },
+        pc: 15,
+        memory_write_log: [],
+        memories: StatePart {
+            value: [],
+        },
+        small_slots: StatePart {
+            value: [
+                0,
+                0,
+                1,
+                0,
+            ],
+        },
+        big_slots: StatePart {
+            value: [
+                1,
+                0,
+                3,
+                3,
+                4,
+                3,
+                1,
+                4,
+                4,
+            ],
+        },
+    },
+    io: Instance {
+        name: <simulator>::counter,
+        instantiated: Module {
+            name: counter,
+            ..
+        },
+    },
+    uninitialized_inputs: {},
+    io_targets: {
+        Instance {
+            name: <simulator>::counter,
+            instantiated: Module {
+                name: counter,
+                ..
+            },
+        }.cd: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: Bundle {
+                    /* offset = 0 */
+                    clk: Clock,
+                    /* offset = 1 */
+                    rst: SyncReset,
+                },
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 2,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::cd.clk",
+                                ty: Clock,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::cd.rst",
+                                ty: SyncReset,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Bundle {
+                    fields: [
+                        CompiledBundleField {
+                            offset: TypeIndex {
+                                small_slots: StatePartIndex<SmallSlots>(0),
+                                big_slots: StatePartIndex<BigSlots>(0),
+                            },
+                            ty: CompiledTypeLayout {
+                                ty: Clock,
+                                layout: TypeLayout {
+                                    small_slots: StatePartLayout<SmallSlots> {
+                                        len: 0,
+                                        debug_data: [],
+                                        ..
+                                    },
+                                    big_slots: StatePartLayout<BigSlots> {
+                                        len: 1,
+                                        debug_data: [
+                                            SlotDebugData {
+                                                name: "",
+                                                ty: Clock,
+                                            },
+                                        ],
+                                        ..
+                                    },
+                                },
+                                body: Scalar,
+                            },
+                        },
+                        CompiledBundleField {
+                            offset: TypeIndex {
+                                small_slots: StatePartIndex<SmallSlots>(0),
+                                big_slots: StatePartIndex<BigSlots>(1),
+                            },
+                            ty: CompiledTypeLayout {
+                                ty: SyncReset,
+                                layout: TypeLayout {
+                                    small_slots: StatePartLayout<SmallSlots> {
+                                        len: 0,
+                                        debug_data: [],
+                                        ..
+                                    },
+                                    big_slots: StatePartLayout<BigSlots> {
+                                        len: 1,
+                                        debug_data: [
+                                            SlotDebugData {
+                                                name: "",
+                                                ty: SyncReset,
+                                            },
+                                        ],
+                                        ..
+                                    },
+                                },
+                                body: Scalar,
+                            },
+                        },
+                    ],
+                },
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 0, len: 2 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::counter,
+            instantiated: Module {
+                name: counter,
+                ..
+            },
+        }.cd.clk: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: Clock,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: Clock,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 0, len: 1 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::counter,
+            instantiated: Module {
+                name: counter,
+                ..
+            },
+        }.cd.rst: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: SyncReset,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: SyncReset,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 1, len: 1 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::counter,
+            instantiated: Module {
+                name: counter,
+                ..
+            },
+        }.count: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: UInt<4>,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(counter: counter).counter::count",
+                                ty: UInt<4>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 2, len: 1 },
+            },
+            write: None,
+        },
+    },
+    made_initial_step: true,
+    needs_settle: false,
+    trace_decls: TraceModule {
+        name: "counter",
+        children: [
+            TraceModuleIO {
+                name: "cd",
+                child: TraceBundle {
+                    name: "cd",
+                    fields: [
+                        TraceClock {
+                            location: TraceScalarId(0),
+                            name: "clk",
+                            flow: Source,
+                        },
+                        TraceSyncReset {
+                            location: TraceScalarId(1),
+                            name: "rst",
+                            flow: Source,
+                        },
+                    ],
+                    ty: Bundle {
+                        /* offset = 0 */
+                        clk: Clock,
+                        /* offset = 1 */
+                        rst: SyncReset,
+                    },
+                    flow: Source,
+                },
+                ty: Bundle {
+                    /* offset = 0 */
+                    clk: Clock,
+                    /* offset = 1 */
+                    rst: SyncReset,
+                },
+                flow: Source,
+            },
+            TraceModuleIO {
+                name: "count",
+                child: TraceUInt {
+                    location: TraceScalarId(2),
+                    name: "count",
+                    ty: UInt<4>,
+                    flow: Sink,
+                },
+                ty: UInt<4>,
+                flow: Sink,
+            },
+            TraceReg {
+                name: "count_reg",
+                child: TraceUInt {
+                    location: TraceScalarId(3),
+                    name: "count_reg",
+                    ty: UInt<4>,
+                    flow: Duplex,
+                },
+                ty: UInt<4>,
+            },
+        ],
+    },
+    traces: [
+        SimTrace {
+            id: TraceScalarId(0),
+            kind: BigClock {
+                index: StatePartIndex<BigSlots>(0),
+            },
+            state: 0x1,
+            last_state: 0x1,
+        },
+        SimTrace {
+            id: TraceScalarId(1),
+            kind: BigSyncReset {
+                index: StatePartIndex<BigSlots>(1),
+            },
+            state: 0x0,
+            last_state: 0x0,
+        },
+        SimTrace {
+            id: TraceScalarId(2),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(2),
+                ty: UInt<4>,
+            },
+            state: 0x3,
+            last_state: 0x2,
+        },
+        SimTrace {
+            id: TraceScalarId(3),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(3),
+                ty: UInt<4>,
+            },
+            state: 0x3,
+            last_state: 0x3,
+        },
+    ],
+    trace_memories: {},
+    trace_writers: [
+        Running(
+            VcdWriter {
+                finished_init: true,
+                timescale: 1 ps,
+                ..
+            },
+        ),
+    ],
+    instant: 66 μs,
+    clocks_triggered: [
+        StatePartIndex<SmallSlots>(1),
+    ],
+    ..
+}

crates/fayalite/tests/sim/expected/counter_sync.vcd

@@ -0,0 +1,214 @@
+$timescale 1 ps $end
+$scope module counter $end
+$scope struct cd $end
+$var wire 1 ! clk $end
+$var wire 1 " rst $end
+$upscope $end
+$var wire 4 # count $end
+$var reg 4 $ count_reg $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+0!
+1"
+b0 #
+b0 $
+$end
+#1000000
+1!
+b11 $
+b11 #
+0"
+#2000000
+0!
+#3000000
+1!
+b100 $
+b100 #
+#4000000
+0!
+#5000000
+1!
+b101 $
+b101 #
+#6000000
+0!
+#7000000
+1!
+b110 $
+b110 #
+#8000000
+0!
+#9000000
+1!
+b111 $
+b111 #
+#10000000
+0!
+#11000000
+1!
+b1000 $
+b1000 #
+#12000000
+0!
+#13000000
+1!
+b1001 $
+b1001 #
+#14000000
+0!
+#15000000
+1!
+b1010 $
+b1010 #
+#16000000
+0!
+#17000000
+1!
+b1011 $
+b1011 #
+#18000000
+0!
+#19000000
+1!
+b1100 $
+b1100 #
+#20000000
+0!
+#21000000
+1!
+b1101 $
+b1101 #
+#22000000
+0!
+#23000000
+1!
+b1110 $
+b1110 #
+#24000000
+0!
+#25000000
+1!
+b1111 $
+b1111 #
+#26000000
+0!
+#27000000
+1!
+b0 $
+b0 #
+#28000000
+0!
+#29000000
+1!
+b1 $
+b1 #
+#30000000
+0!
+#31000000
+1!
+b10 $
+b10 #
+#32000000
+0!
+#33000000
+1!
+b11 $
+b11 #
+#34000000
+0!
+#35000000
+1!
+b100 $
+b100 #
+#36000000
+0!
+#37000000
+1!
+b101 $
+b101 #
+#38000000
+0!
+#39000000
+1!
+b110 $
+b110 #
+#40000000
+0!
+#41000000
+1!
+b111 $
+b111 #
+#42000000
+0!
+#43000000
+1!
+b1000 $
+b1000 #
+#44000000
+0!
+#45000000
+1!
+b1001 $
+b1001 #
+#46000000
+0!
+#47000000
+1!
+b1010 $
+b1010 #
+#48000000
+0!
+#49000000
+1!
+b1011 $
+b1011 #
+#50000000
+0!
+#51000000
+1!
+b1100 $
+b1100 #
+#52000000
+0!
+#53000000
+1!
+b1101 $
+b1101 #
+#54000000
+0!
+#55000000
+1!
+b1110 $
+b1110 #
+#56000000
+0!
+#57000000
+1!
+b1111 $
+b1111 #
+#58000000
+0!
+#59000000
+1!
+b0 $
+b0 #
+#60000000
+0!
+#61000000
+1!
+b1 $
+b1 #
+#62000000
+0!
+#63000000
+1!
+b10 $
+b10 #
+#64000000
+0!
+#65000000
+1!
+b11 $
+b11 #
+#66000000

crates/fayalite/tests/sim/expected/duplicate_names.txt

@@ -0,0 +1,153 @@
+Simulation {
+    state: State {
+        insns: Insns {
+            state_layout: StateLayout {
+                ty: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 4,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(duplicate_names: duplicate_names).duplicate_names::w",
+                                ty: UInt<8>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<8>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(duplicate_names: duplicate_names).duplicate_names::w",
+                                ty: UInt<8>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<8>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                memories: StatePartLayout<Memories> {
+                    len: 0,
+                    debug_data: [],
+                    layout_data: [],
+                    ..
+                },
+            },
+            insns: [
+                // at: module-XXXXXXXXXX.rs:1:1
+                0: Const {
+                    dest: StatePartIndex<BigSlots>(3), // (0x6) SlotDebugData { name: "", ty: UInt<8> },
+                    value: 0x6,
+                },
+                // at: module-XXXXXXXXXX.rs:5:1
+                1: Copy {
+                    dest: StatePartIndex<BigSlots>(2), // (0x6) SlotDebugData { name: "InstantiatedModule(duplicate_names: duplicate_names).duplicate_names::w", ty: UInt<8> },
+                    src: StatePartIndex<BigSlots>(3), // (0x6) SlotDebugData { name: "", ty: UInt<8> },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                2: Const {
+                    dest: StatePartIndex<BigSlots>(1), // (0x5) SlotDebugData { name: "", ty: UInt<8> },
+                    value: 0x5,
+                },
+                // at: module-XXXXXXXXXX.rs:3:1
+                3: Copy {
+                    dest: StatePartIndex<BigSlots>(0), // (0x5) SlotDebugData { name: "InstantiatedModule(duplicate_names: duplicate_names).duplicate_names::w", ty: UInt<8> },
+                    src: StatePartIndex<BigSlots>(1), // (0x5) SlotDebugData { name: "", ty: UInt<8> },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                4: Return,
+            ],
+            ..
+        },
+        pc: 4,
+        memory_write_log: [],
+        memories: StatePart {
+            value: [],
+        },
+        small_slots: StatePart {
+            value: [],
+        },
+        big_slots: StatePart {
+            value: [
+                5,
+                5,
+                6,
+                6,
+            ],
+        },
+    },
+    io: Instance {
+        name: <simulator>::duplicate_names,
+        instantiated: Module {
+            name: duplicate_names,
+            ..
+        },
+    },
+    uninitialized_inputs: {},
+    io_targets: {},
+    made_initial_step: true,
+    needs_settle: false,
+    trace_decls: TraceModule {
+        name: "duplicate_names",
+        children: [
+            TraceWire {
+                name: "w",
+                child: TraceUInt {
+                    location: TraceScalarId(0),
+                    name: "w",
+                    ty: UInt<8>,
+                    flow: Duplex,
+                },
+                ty: UInt<8>,
+            },
+            TraceWire {
+                name: "w",
+                child: TraceUInt {
+                    location: TraceScalarId(1),
+                    name: "w",
+                    ty: UInt<8>,
+                    flow: Duplex,
+                },
+                ty: UInt<8>,
+            },
+        ],
+    },
+    traces: [
+        SimTrace {
+            id: TraceScalarId(0),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(0),
+                ty: UInt<8>,
+            },
+            state: 0x05,
+            last_state: 0x05,
+        },
+        SimTrace {
+            id: TraceScalarId(1),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(2),
+                ty: UInt<8>,
+            },
+            state: 0x06,
+            last_state: 0x06,
+        },
+    ],
+    trace_memories: {},
+    trace_writers: [
+        Running(
+            VcdWriter {
+                finished_init: true,
+                timescale: 1 ps,
+                ..
+            },
+        ),
+    ],
+    instant: 1 μs,
+    clocks_triggered: [],
+    ..
+}

crates/fayalite/tests/sim/expected/duplicate_names.vcd

@@ -0,0 +1,11 @@
+$timescale 1 ps $end
+$scope module duplicate_names $end
+$var wire 8 ! w $end
+$var wire 8 " w_2 $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+b101 !
+b110 "
+$end
+#1000000

crates/fayalite/tests/sim/expected/enums.vcd

@@ -0,0 +1,110 @@
+$timescale 1 ps $end
+$scope module enums $end
+$scope struct cd $end
+$var wire 1 ! clk $end
+$var wire 1 " rst $end
+$upscope $end
+$var wire 1 # en $end
+$var wire 2 $ which_in $end
+$var wire 4 % data_in $end
+$var wire 2 & which_out $end
+$var wire 4 ' data_out $end
+$scope struct b_out $end
+$var string 1 ( \$tag $end
+$scope struct HdlSome $end
+$var wire 1 ) \0 $end
+$var wire 1 * \1 $end
+$upscope $end
+$upscope $end
+$scope struct the_reg $end
+$var string 1 + \$tag $end
+$scope struct B $end
+$var reg 1 , \0 $end
+$var reg 1 - \1 $end
+$upscope $end
+$scope struct C $end
+$scope struct a $end
+$var reg 1 . \[0] $end
+$var reg 1 / \[1] $end
+$upscope $end
+$var reg 2 0 b $end
+$upscope $end
+$upscope $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+0!
+1"
+0#
+b0 $
+b0 %
+b0 &
+b0 '
+sHdlNone\x20(0) (
+0)
+0*
+sA\x20(0) +
+0,
+0-
+0.
+0/
+b0 0
+$end
+#1000000
+1!
+#1100000
+0"
+#2000000
+0!
+#3000000
+1!
+#4000000
+1#
+b1 $
+0!
+#5000000
+1!
+b1 &
+sHdlSome\x20(1) (
+sB\x20(1) +
+#6000000
+0#
+b0 $
+0!
+#7000000
+1!
+#8000000
+1#
+b1 $
+b1111 %
+0!
+#9000000
+1!
+b11 '
+1)
+1*
+1,
+1-
+1.
+1/
+#10000000
+0!
+#11000000
+1!
+#12000000
+b10 $
+0!
+#13000000
+1!
+b10 &
+b1111 '
+sHdlNone\x20(0) (
+0)
+0*
+sC\x20(2) +
+b11 0
+#14000000
+0!
+#15000000
+1!
+#16000000

crates/fayalite/tests/sim/expected/memories.vcd

@@ -0,0 +1,408 @@
+$timescale 1 ps $end
+$scope module memories $end
+$scope struct r $end
+$var wire 4 ! addr $end
+$var wire 1 " en $end
+$var wire 1 # clk $end
+$scope struct data $end
+$var wire 8 $ \0 $end
+$var wire 8 % \1 $end
+$upscope $end
+$upscope $end
+$scope struct w $end
+$var wire 4 & addr $end
+$var wire 1 ' en $end
+$var wire 1 ( clk $end
+$scope struct data $end
+$var wire 8 ) \0 $end
+$var wire 8 * \1 $end
+$upscope $end
+$scope struct mask $end
+$var wire 1 + \0 $end
+$var wire 1 , \1 $end
+$upscope $end
+$upscope $end
+$scope struct mem $end
+$scope struct contents $end
+$scope struct \[0] $end
+$scope struct mem $end
+$var reg 8 9 \0 $end
+$var reg 8 I \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[1] $end
+$scope struct mem $end
+$var reg 8 : \0 $end
+$var reg 8 J \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[2] $end
+$scope struct mem $end
+$var reg 8 ; \0 $end
+$var reg 8 K \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[3] $end
+$scope struct mem $end
+$var reg 8 < \0 $end
+$var reg 8 L \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[4] $end
+$scope struct mem $end
+$var reg 8 = \0 $end
+$var reg 8 M \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[5] $end
+$scope struct mem $end
+$var reg 8 > \0 $end
+$var reg 8 N \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[6] $end
+$scope struct mem $end
+$var reg 8 ? \0 $end
+$var reg 8 O \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[7] $end
+$scope struct mem $end
+$var reg 8 @ \0 $end
+$var reg 8 P \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[8] $end
+$scope struct mem $end
+$var reg 8 A \0 $end
+$var reg 8 Q \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[9] $end
+$scope struct mem $end
+$var reg 8 B \0 $end
+$var reg 8 R \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[10] $end
+$scope struct mem $end
+$var reg 8 C \0 $end
+$var reg 8 S \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[11] $end
+$scope struct mem $end
+$var reg 8 D \0 $end
+$var reg 8 T \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[12] $end
+$scope struct mem $end
+$var reg 8 E \0 $end
+$var reg 8 U \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[13] $end
+$scope struct mem $end
+$var reg 8 F \0 $end
+$var reg 8 V \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[14] $end
+$scope struct mem $end
+$var reg 8 G \0 $end
+$var reg 8 W \1 $end
+$upscope $end
+$upscope $end
+$scope struct \[15] $end
+$scope struct mem $end
+$var reg 8 H \0 $end
+$var reg 8 X \1 $end
+$upscope $end
+$upscope $end
+$upscope $end
+$scope struct r0 $end
+$var wire 4 - addr $end
+$var wire 1 . en $end
+$var wire 1 / clk $end
+$scope struct data $end
+$var wire 8 0 \0 $end
+$var wire 8 1 \1 $end
+$upscope $end
+$upscope $end
+$scope struct w1 $end
+$var wire 4 2 addr $end
+$var wire 1 3 en $end
+$var wire 1 4 clk $end
+$scope struct data $end
+$var wire 8 5 \0 $end
+$var wire 8 6 \1 $end
+$upscope $end
+$scope struct mask $end
+$var wire 1 7 \0 $end
+$var wire 1 8 \1 $end
+$upscope $end
+$upscope $end
+$upscope $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+b1 9
+b100011 I
+b1 :
+b100011 J
+b1 ;
+b100011 K
+b1 <
+b100011 L
+b1 =
+b100011 M
+b1 >
+b100011 N
+b1 ?
+b100011 O
+b1 @
+b100011 P
+b1 A
+b100011 Q
+b1 B
+b100011 R
+b1 C
+b100011 S
+b1 D
+b100011 T
+b1 E
+b100011 U
+b1 F
+b100011 V
+b1 G
+b100011 W
+b1 H
+b100011 X
+b0 !
+0"
+0#
+b0 $
+b0 %
+b0 &
+0'
+0(
+b0 )
+b0 *
+0+
+0,
+b0 -
+0.
+0/
+b0 0
+b0 1
+b0 2
+03
+04
+b0 5
+b0 6
+07
+08
+$end
+#1000000
+1#
+1(
+1/
+14
+#2000000
+1"
+0#
+b1 $
+b100011 %
+1'
+0(
+b10000 )
+b100000 *
+1+
+1,
+1.
+0/
+b1 0
+b100011 1
+13
+04
+b10000 5
+b100000 6
+17
+18
+#3000000
+b10000 9
+b100000 I
+1#
+1(
+1/
+14
+b10000 $
+b100000 %
+b10000 0
+b100000 1
+#4000000
+0#
+0(
+b110000 )
+b1000000 *
+0+
+0/
+04
+b110000 5
+b1000000 6
+07
+#5000000
+b10000 9
+b1000000 I
+1#
+1(
+1/
+14
+b1000000 %
+b1000000 1
+#6000000
+0#
+0(
+b1010000 )
+b1100000 *
+1+
+0,
+0/
+04
+b1010000 5
+b1100000 6
+17
+08
+#7000000
+b1010000 9
+b1000000 I
+1#
+1(
+1/
+14
+b1010000 $
+b1010000 0
+#8000000
+0#
+0(
+b1110000 )
+b10000000 *
+0+
+0/
+04
+b1110000 5
+b10000000 6
+07
+#9000000
+1#
+1(
+1/
+14
+#10000000
+0#
+0'
+0(
+b10010000 )
+b10100000 *
+0/
+03
+04
+b10010000 5
+b10100000 6
+#11000000
+1#
+1(
+1/
+14
+#12000000
+0#
+b1 &
+1'
+0(
+1+
+1,
+0/
+b1 2
+13
+04
+17
+18
+#13000000
+b10010000 :
+b10100000 J
+1#
+1(
+1/
+14
+#14000000
+0#
+b10 &
+0(
+b10110000 )
+b11000000 *
+0/
+b10 2
+04
+b10110000 5
+b11000000 6
+#15000000
+b10110000 ;
+b11000000 K
+1#
+1(
+1/
+14
+#16000000
+0#
+0'
+0(
+b11010000 )
+b11100000 *
+0/
+03
+04
+b11010000 5
+b11100000 6
+#17000000
+1#
+1(
+1/
+14
+#18000000
+b1 !
+0#
+b10010000 $
+b10100000 %
+0(
+b1 -
+0/
+b10010000 0
+b10100000 1
+04
+#19000000
+1#
+1(
+1/
+14
+#20000000
+b10 !
+0#
+b10110000 $
+b11000000 %
+0(
+b10 -
+0/
+b10110000 0
+b11000000 1
+04
+#21000000
+1#
+1(
+1/
+14
+#22000000
+0#
+0(
+0/
+04

crates/fayalite/tests/sim/expected/memories2.vcd

@@ -0,0 +1,363 @@
+$timescale 1 ps $end
+$scope module memories2 $end
+$scope struct rw $end
+$var wire 3 ! addr $end
+$var wire 1 " en $end
+$var wire 1 # clk $end
+$var wire 2 $ rdata $end
+$var wire 1 % wmode $end
+$var wire 2 & wdata $end
+$var wire 1 ' wmask $end
+$upscope $end
+$scope struct mem $end
+$scope struct contents $end
+$scope struct \[0] $end
+$scope struct mem $end
+$var string 1 1 \$tag $end
+$var reg 1 6 HdlSome $end
+$upscope $end
+$upscope $end
+$scope struct \[1] $end
+$scope struct mem $end
+$var string 1 2 \$tag $end
+$var reg 1 7 HdlSome $end
+$upscope $end
+$upscope $end
+$scope struct \[2] $end
+$scope struct mem $end
+$var string 1 3 \$tag $end
+$var reg 1 8 HdlSome $end
+$upscope $end
+$upscope $end
+$scope struct \[3] $end
+$scope struct mem $end
+$var string 1 4 \$tag $end
+$var reg 1 9 HdlSome $end
+$upscope $end
+$upscope $end
+$scope struct \[4] $end
+$scope struct mem $end
+$var string 1 5 \$tag $end
+$var reg 1 : HdlSome $end
+$upscope $end
+$upscope $end
+$upscope $end
+$scope struct rw0 $end
+$var wire 3 ( addr $end
+$var wire 1 ) en $end
+$var wire 1 * clk $end
+$scope struct rdata $end
+$var string 1 + \$tag $end
+$var wire 1 , HdlSome $end
+$upscope $end
+$var wire 1 - wmode $end
+$scope struct wdata $end
+$var string 1 . \$tag $end
+$var wire 1 / HdlSome $end
+$upscope $end
+$var wire 1 0 wmask $end
+$upscope $end
+$upscope $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+sHdlSome\x20(1) 1
+16
+sHdlSome\x20(1) 2
+17
+sHdlSome\x20(1) 3
+18
+sHdlSome\x20(1) 4
+19
+sHdlSome\x20(1) 5
+1:
+b0 !
+0"
+0#
+b0 $
+0%
+b0 &
+0'
+b0 (
+0)
+0*
+sHdlNone\x20(0) +
+0,
+0-
+sHdlNone\x20(0) .
+0/
+00
+$end
+#250000
+1#
+1*
+#500000
+#750000
+0#
+0*
+#1000000
+1"
+1)
+#1250000
+1#
+1*
+b11 $
+sHdlSome\x20(1) +
+1,
+#1500000
+#1750000
+0#
+0*
+#2000000
+0"
+0)
+#2250000
+1#
+1*
+b0 $
+sHdlNone\x20(0) +
+0,
+#2500000
+#2750000
+0#
+0*
+#3000000
+1"
+1%
+1'
+1)
+1-
+10
+#3250000
+sHdlNone\x20(0) 1
+06
+1#
+1*
+#3500000
+#3750000
+0#
+0*
+#4000000
+0%
+0'
+0-
+00
+#4250000
+1#
+1*
+#4500000
+#4750000
+0#
+0*
+#5000000
+1%
+b11 &
+1-
+sHdlSome\x20(1) .
+1/
+#5250000
+1#
+1*
+#5500000
+#5750000
+0#
+0*
+#6000000
+b1 !
+b1 &
+1'
+b1 (
+0/
+10
+#6250000
+sHdlSome\x20(1) 2
+07
+1#
+1*
+#6500000
+#6750000
+0#
+0*
+#7000000
+b10 !
+b10 &
+b10 (
+sHdlNone\x20(0) .
+#7250000
+sHdlNone\x20(0) 3
+08
+1#
+1*
+#7500000
+#7750000
+0#
+0*
+#8000000
+b11 !
+b11 &
+b11 (
+sHdlSome\x20(1) .
+1/
+#8250000
+sHdlSome\x20(1) 4
+19
+1#
+1*
+#8500000
+#8750000
+0#
+0*
+#9000000
+b100 !
+b10 &
+b100 (
+sHdlNone\x20(0) .
+0/
+#9250000
+sHdlNone\x20(0) 5
+0:
+1#
+1*
+#9500000
+#9750000
+0#
+0*
+#10000000
+b101 !
+b1 &
+b101 (
+sHdlSome\x20(1) .
+#10250000
+1#
+1*
+#10500000
+#10750000
+0#
+0*
+#11000000
+b110 !
+b110 (
+#11250000
+1#
+1*
+#11500000
+#11750000
+0#
+0*
+#12000000
+b111 !
+b111 (
+#12250000
+1#
+1*
+#12500000
+#12750000
+0#
+0*
+#13000000
+0%
+b0 &
+0'
+0-
+sHdlNone\x20(0) .
+00
+#13250000
+1#
+1*
+#13500000
+#13750000
+0#
+0*
+#14000000
+b110 !
+b110 (
+#14250000
+1#
+1*
+#14500000
+#14750000
+0#
+0*
+#15000000
+b101 !
+b101 (
+#15250000
+1#
+1*
+#15500000
+#15750000
+0#
+0*
+#16000000
+b100 !
+b100 (
+#16250000
+1#
+1*
+#16500000
+#16750000
+0#
+0*
+#17000000
+b11 !
+b11 (
+#17250000
+1#
+1*
+b11 $
+sHdlSome\x20(1) +
+1,
+#17500000
+#17750000
+0#
+0*
+#18000000
+b10 !
+b10 (
+#18250000
+1#
+1*
+b0 $
+sHdlNone\x20(0) +
+0,
+#18500000
+#18750000
+0#
+0*
+#19000000
+b0 !
+b0 (
+#19250000
+1#
+1*
+#19500000
+#19750000
+0#
+0*
+#20000000
+b1 !
+b1 (
+#20250000
+1#
+1*
+b1 $
+sHdlSome\x20(1) +
+#20500000
+#20750000
+0#
+0*
+#21000000
+b0 !
+0"
+b0 (
+0)
+#21250000
+1#
+1*
+b0 $
+sHdlNone\x20(0) +
+#21500000
+#21750000
+0#
+0*
+#22000000

crates/fayalite/tests/sim/expected/memories3.vcd

@@ -0,0 +1,836 @@
+$timescale 1 ps $end
+$scope module memories3 $end
+$scope struct r $end
+$var wire 3 ! addr $end
+$var wire 1 " en $end
+$var wire 1 # clk $end
+$scope struct data $end
+$var wire 8 $ \[0] $end
+$var wire 8 % \[1] $end
+$var wire 8 & \[2] $end
+$var wire 8 ' \[3] $end
+$var wire 8 ( \[4] $end
+$var wire 8 ) \[5] $end
+$var wire 8 * \[6] $end
+$var wire 8 + \[7] $end
+$upscope $end
+$upscope $end
+$scope struct w $end
+$var wire 3 , addr $end
+$var wire 1 - en $end
+$var wire 1 . clk $end
+$scope struct data $end
+$var wire 8 / \[0] $end
+$var wire 8 0 \[1] $end
+$var wire 8 1 \[2] $end
+$var wire 8 2 \[3] $end
+$var wire 8 3 \[4] $end
+$var wire 8 4 \[5] $end
+$var wire 8 5 \[6] $end
+$var wire 8 6 \[7] $end
+$upscope $end
+$scope struct mask $end
+$var wire 1 7 \[0] $end
+$var wire 1 8 \[1] $end
+$var wire 1 9 \[2] $end
+$var wire 1 : \[3] $end
+$var wire 1 ; \[4] $end
+$var wire 1 < \[5] $end
+$var wire 1 = \[6] $end
+$var wire 1 > \[7] $end
+$upscope $end
+$upscope $end
+$scope struct mem $end
+$scope struct contents $end
+$scope struct \[0] $end
+$scope struct mem $end
+$var reg 8 ] \[0] $end
+$var reg 8 e \[1] $end
+$var reg 8 m \[2] $end
+$var reg 8 u \[3] $end
+$var reg 8 } \[4] $end
+$var reg 8 '" \[5] $end
+$var reg 8 /" \[6] $end
+$var reg 8 7" \[7] $end
+$upscope $end
+$upscope $end
+$scope struct \[1] $end
+$scope struct mem $end
+$var reg 8 ^ \[0] $end
+$var reg 8 f \[1] $end
+$var reg 8 n \[2] $end
+$var reg 8 v \[3] $end
+$var reg 8 ~ \[4] $end
+$var reg 8 (" \[5] $end
+$var reg 8 0" \[6] $end
+$var reg 8 8" \[7] $end
+$upscope $end
+$upscope $end
+$scope struct \[2] $end
+$scope struct mem $end
+$var reg 8 _ \[0] $end
+$var reg 8 g \[1] $end
+$var reg 8 o \[2] $end
+$var reg 8 w \[3] $end
+$var reg 8 !" \[4] $end
+$var reg 8 )" \[5] $end
+$var reg 8 1" \[6] $end
+$var reg 8 9" \[7] $end
+$upscope $end
+$upscope $end
+$scope struct \[3] $end
+$scope struct mem $end
+$var reg 8 ` \[0] $end
+$var reg 8 h \[1] $end
+$var reg 8 p \[2] $end
+$var reg 8 x \[3] $end
+$var reg 8 "" \[4] $end
+$var reg 8 *" \[5] $end
+$var reg 8 2" \[6] $end
+$var reg 8 :" \[7] $end
+$upscope $end
+$upscope $end
+$scope struct \[4] $end
+$scope struct mem $end
+$var reg 8 a \[0] $end
+$var reg 8 i \[1] $end
+$var reg 8 q \[2] $end
+$var reg 8 y \[3] $end
+$var reg 8 #" \[4] $end
+$var reg 8 +" \[5] $end
+$var reg 8 3" \[6] $end
+$var reg 8 ;" \[7] $end
+$upscope $end
+$upscope $end
+$scope struct \[5] $end
+$scope struct mem $end
+$var reg 8 b \[0] $end
+$var reg 8 j \[1] $end
+$var reg 8 r \[2] $end
+$var reg 8 z \[3] $end
+$var reg 8 $" \[4] $end
+$var reg 8 ," \[5] $end
+$var reg 8 4" \[6] $end
+$var reg 8 <" \[7] $end
+$upscope $end
+$upscope $end
+$scope struct \[6] $end
+$scope struct mem $end
+$var reg 8 c \[0] $end
+$var reg 8 k \[1] $end
+$var reg 8 s \[2] $end
+$var reg 8 { \[3] $end
+$var reg 8 %" \[4] $end
+$var reg 8 -" \[5] $end
+$var reg 8 5" \[6] $end
+$var reg 8 =" \[7] $end
+$upscope $end
+$upscope $end
+$scope struct \[7] $end
+$scope struct mem $end
+$var reg 8 d \[0] $end
+$var reg 8 l \[1] $end
+$var reg 8 t \[2] $end
+$var reg 8 | \[3] $end
+$var reg 8 &" \[4] $end
+$var reg 8 ." \[5] $end
+$var reg 8 6" \[6] $end
+$var reg 8 >" \[7] $end
+$upscope $end
+$upscope $end
+$upscope $end
+$scope struct r0 $end
+$var wire 3 ? addr $end
+$var wire 1 @ en $end
+$var wire 1 A clk $end
+$scope struct data $end
+$var wire 8 B \[0] $end
+$var wire 8 C \[1] $end
+$var wire 8 D \[2] $end
+$var wire 8 E \[3] $end
+$var wire 8 F \[4] $end
+$var wire 8 G \[5] $end
+$var wire 8 H \[6] $end
+$var wire 8 I \[7] $end
+$upscope $end
+$upscope $end
+$scope struct w1 $end
+$var wire 3 J addr $end
+$var wire 1 K en $end
+$var wire 1 L clk $end
+$scope struct data $end
+$var wire 8 M \[0] $end
+$var wire 8 N \[1] $end
+$var wire 8 O \[2] $end
+$var wire 8 P \[3] $end
+$var wire 8 Q \[4] $end
+$var wire 8 R \[5] $end
+$var wire 8 S \[6] $end
+$var wire 8 T \[7] $end
+$upscope $end
+$scope struct mask $end
+$var wire 1 U \[0] $end
+$var wire 1 V \[1] $end
+$var wire 1 W \[2] $end
+$var wire 1 X \[3] $end
+$var wire 1 Y \[4] $end
+$var wire 1 Z \[5] $end
+$var wire 1 [ \[6] $end
+$var wire 1 \ \[7] $end
+$upscope $end
+$upscope $end
+$upscope $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+b0 ]
+b0 e
+b0 m
+b0 u
+b0 }
+b0 '"
+b0 /"
+b0 7"
+b0 ^
+b0 f
+b0 n
+b0 v
+b0 ~
+b0 ("
+b0 0"
+b0 8"
+b0 _
+b0 g
+b0 o
+b0 w
+b0 !"
+b0 )"
+b0 1"
+b0 9"
+b0 `
+b0 h
+b0 p
+b0 x
+b0 ""
+b0 *"
+b0 2"
+b0 :"
+b0 a
+b0 i
+b0 q
+b0 y
+b0 #"
+b0 +"
+b0 3"
+b0 ;"
+b0 b
+b0 j
+b0 r
+b0 z
+b0 $"
+b0 ,"
+b0 4"
+b0 <"
+b0 c
+b0 k
+b0 s
+b0 {
+b0 %"
+b0 -"
+b0 5"
+b0 ="
+b0 d
+b0 l
+b0 t
+b0 |
+b0 &"
+b0 ."
+b0 6"
+b0 >"
+b0 !
+0"
+0#
+b0 $
+b0 %
+b0 &
+b0 '
+b0 (
+b0 )
+b0 *
+b0 +
+b0 ,
+1-
+0.
+b10010 /
+b110100 0
+b1010110 1
+b1111000 2
+b10011010 3
+b10111100 4
+b11011110 5
+b11110000 6
+07
+18
+09
+1:
+1;
+0<
+0=
+1>
+b0 ?
+0@
+0A
+b0 B
+b0 C
+b0 D
+b0 E
+b0 F
+b0 G
+b0 H
+b0 I
+b0 J
+1K
+0L
+b10010 M
+b110100 N
+b1010110 O
+b1111000 P
+b10011010 Q
+b10111100 R
+b11011110 S
+b11110000 T
+0U
+1V
+0W
+1X
+1Y
+0Z
+0[
+1\
+$end
+#250000
+1#
+1.
+1A
+1L
+#500000
+#750000
+0#
+0.
+0A
+0L
+#1000000
+1"
+b1 ,
+0-
+b0 /
+b0 0
+b0 1
+b0 2
+b0 3
+b0 4
+b0 5
+b0 6
+08
+0:
+0;
+0>
+1@
+b1 J
+0K
+b0 M
+b0 N
+b0 O
+b0 P
+b0 Q
+b0 R
+b0 S
+b0 T
+0V
+0X
+0Y
+0\
+#1250000
+b0 ]
+b110100 e
+b0 m
+b1111000 u
+b10011010 }
+b0 '"
+b0 /"
+b11110000 7"
+1#
+1.
+1A
+1L
+#1500000
+#1750000
+0#
+0.
+0A
+0L
+#2000000
+#2250000
+1#
+1.
+1A
+1L
+#2500000
+#2750000
+0#
+0.
+0A
+0L
+#3000000
+b0 ,
+1-
+b11111110 /
+b11011100 0
+b10111010 1
+b10011000 2
+b1110110 3
+b1010100 4
+b110010 5
+b10000 6
+17
+18
+19
+1:
+1;
+1<
+1=
+1>
+b0 J
+1K
+b11111110 M
+b11011100 N
+b10111010 O
+b10011000 P
+b1110110 Q
+b1010100 R
+b110010 S
+b10000 T
+1U
+1V
+1W
+1X
+1Y
+1Z
+1[
+1\
+#3250000
+1#
+1.
+1A
+b110100 C
+b1111000 E
+b10011010 F
+b11110000 I
+1L
+b110100 %
+b1111000 '
+b10011010 (
+b11110000 +
+#3500000
+#3750000
+0#
+0.
+0A
+0L
+#4000000
+#4250000
+b11111110 ]
+b11011100 e
+b10111010 m
+b10011000 u
+b1110110 }
+b1010100 '"
+b110010 /"
+b10000 7"
+1#
+1.
+1A
+1L
+#4500000
+#4750000
+0#
+0.
+0A
+0L
+#5000000
+#5250000
+b11111110 ]
+b11011100 e
+b10111010 m
+b10011000 u
+b1110110 }
+b1010100 '"
+b110010 /"
+b10000 7"
+1#
+1.
+1A
+1L
+#5500000
+#5750000
+0#
+0.
+0A
+0L
+#6000000
+0"
+b1 ,
+b10011 /
+b1010111 0
+b10011011 1
+b11011111 2
+b10 3
+b1000110 4
+b10001010 5
+b11001110 6
+0@
+b1 J
+b10011 M
+b1010111 N
+b10011011 O
+b11011111 P
+b10 Q
+b1000110 R
+b10001010 S
+b11001110 T
+#6250000
+b11111110 ]
+b11011100 e
+b10111010 m
+b10011000 u
+b1110110 }
+b1010100 '"
+b110010 /"
+b10000 7"
+1#
+1.
+1A
+b11111110 B
+b11011100 C
+b10111010 D
+b10011000 E
+b1110110 F
+b1010100 G
+b110010 H
+b10000 I
+1L
+b11111110 $
+b11011100 %
+b10111010 &
+b10011000 '
+b1110110 (
+b1010100 )
+b110010 *
+b10000 +
+#6500000
+#6750000
+0#
+0.
+0A
+0L
+#7000000
+b10 ,
+b1110100 /
+b1100101 0
+b1110011 1
+b1110100 2
+b1101001 3
+b1101110 4
+b1100111 5
+b100001 6
+b10 J
+b1110100 M
+b1100101 N
+b1110011 O
+b1110100 P
+b1101001 Q
+b1101110 R
+b1100111 S
+b100001 T
+#7250000
+b10011 ^
+b1010111 f
+b10011011 n
+b11011111 v
+b10 ~
+b1000110 ("
+b10001010 0"
+b11001110 8"
+1#
+1.
+1A
+b0 B
+b0 C
+b0 D
+b0 E
+b0 F
+b0 G
+b0 H
+b0 I
+1L
+b0 $
+b0 %
+b0 &
+b0 '
+b0 (
+b0 )
+b0 *
+b0 +
+#7500000
+#7750000
+0#
+0.
+0A
+0L
+#8000000
+b11 ,
+b1101101 /
+b1101111 0
+b1110010 1
+b1100101 2
+b100000 3
+b1110100 4
+b1110011 5
+b1110100 6
+b11 J
+b1101101 M
+b1101111 N
+b1110010 O
+b1100101 P
+b100000 Q
+b1110100 R
+b1110011 S
+b1110100 T
+#8250000
+b1110100 _
+b1100101 g
+b1110011 o
+b1110100 w
+b1101001 !"
+b1101110 )"
+b1100111 1"
+b100001 9"
+1#
+1.
+1A
+1L
+#8500000
+#8750000
+0#
+0.
+0A
+0L
+#9000000
+1"
+b0 ,
+0-
+b0 /
+b0 0
+b0 1
+b0 2
+b0 3
+b0 4
+b0 5
+b0 6
+07
+08
+09
+0:
+0;
+0<
+0=
+0>
+1@
+b0 J
+0K
+b0 M
+b0 N
+b0 O
+b0 P
+b0 Q
+b0 R
+b0 S
+b0 T
+0U
+0V
+0W
+0X
+0Y
+0Z
+0[
+0\
+#9250000
+b1101101 `
+b1101111 h
+b1110010 p
+b1100101 x
+b100000 ""
+b1110100 *"
+b1110011 2"
+b1110100 :"
+1#
+1.
+1A
+1L
+#9500000
+#9750000
+0#
+0.
+0A
+0L
+#10000000
+b1 !
+b1 ?
+#10250000
+1#
+1.
+1A
+b11111110 B
+b11011100 C
+b10111010 D
+b10011000 E
+b1110110 F
+b1010100 G
+b110010 H
+b10000 I
+1L
+b11111110 $
+b11011100 %
+b10111010 &
+b10011000 '
+b1110110 (
+b1010100 )
+b110010 *
+b10000 +
+#10500000
+#10750000
+0#
+0.
+0A
+0L
+#11000000
+b10 !
+b10 ?
+#11250000
+1#
+1.
+1A
+b10011 B
+b1010111 C
+b10011011 D
+b11011111 E
+b10 F
+b1000110 G
+b10001010 H
+b11001110 I
+1L
+b10011 $
+b1010111 %
+b10011011 &
+b11011111 '
+b10 (
+b1000110 )
+b10001010 *
+b11001110 +
+#11500000
+#11750000
+0#
+0.
+0A
+0L
+#12000000
+b11 !
+b11 ?
+#12250000
+1#
+1.
+1A
+b1110100 B
+b1100101 C
+b1110011 D
+b1110100 E
+b1101001 F
+b1101110 G
+b1100111 H
+b100001 I
+1L
+b1110100 $
+b1100101 %
+b1110011 &
+b1110100 '
+b1101001 (
+b1101110 )
+b1100111 *
+b100001 +
+#12500000
+#12750000
+0#
+0.
+0A
+0L
+#13000000
+b0 !
+0"
+b0 ?
+0@
+#13250000
+1#
+1.
+1A
+b1101101 B
+b1101111 C
+b1110010 D
+b1100101 E
+b100000 F
+b1110100 G
+b1110011 H
+b1110100 I
+1L
+b1101101 $
+b1101111 %
+b1110010 &
+b1100101 '
+b100000 (
+b1110100 )
+b1110011 *
+b1110100 +
+#13500000
+#13750000
+0#
+0.
+0A
+0L
+#14000000
+#14250000
+1#
+1.
+1A
+b0 B
+b0 C
+b0 D
+b0 E
+b0 F
+b0 G
+b0 H
+b0 I
+1L
+b0 $
+b0 %
+b0 &
+b0 '
+b0 (
+b0 )
+b0 *
+b0 +
+#14500000
+#14750000
+0#
+0.
+0A
+0L
+#15000000

crates/fayalite/tests/sim/expected/mod1.txt

@@ -0,0 +1,810 @@
+Simulation {
+    state: State {
+        insns: Insns {
+            state_layout: StateLayout {
+                ty: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 17,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::o.i",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::o.o",
+                                ty: SInt<2>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::o.i2",
+                                ty: SInt<2>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::o.o2",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::child.i",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::child.o",
+                                ty: SInt<2>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::child.i2",
+                                ty: SInt<2>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::child.o2",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::i",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::o",
+                                ty: SInt<2>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::i2",
+                                ty: SInt<2>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::o2",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: SInt<2>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<4>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                memories: StatePartLayout<Memories> {
+                    len: 0,
+                    debug_data: [],
+                    layout_data: [],
+                    ..
+                },
+            },
+            insns: [
+                // at: module-XXXXXXXXXX.rs:4:1
+                0: Copy {
+                    dest: StatePartIndex<BigSlots>(6), // (-0x2) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::child.i2", ty: SInt<2> },
+                    src: StatePartIndex<BigSlots>(2), // (-0x2) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::o.i2", ty: SInt<2> },
+                },
+                1: Copy {
+                    dest: StatePartIndex<BigSlots>(4), // (0xa) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::child.i", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(0), // (0xa) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::o.i", ty: UInt<4> },
+                },
+                // at: module-XXXXXXXXXX.rs:2:1
+                2: Copy {
+                    dest: StatePartIndex<BigSlots>(10), // (-0x2) SlotDebugData { name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::i2", ty: SInt<2> },
+                    src: StatePartIndex<BigSlots>(6), // (-0x2) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::child.i2", ty: SInt<2> },
+                },
+                3: Copy {
+                    dest: StatePartIndex<BigSlots>(8), // (0xa) SlotDebugData { name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::i", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(4), // (0xa) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::child.i", ty: UInt<4> },
+                },
+                // at: module-XXXXXXXXXX-2.rs:1:1
+                4: Const {
+                    dest: StatePartIndex<BigSlots>(16), // (0xf) SlotDebugData { name: "", ty: UInt<4> },
+                    value: 0xf,
+                },
+                5: Const {
+                    dest: StatePartIndex<BigSlots>(14), // (0x5) SlotDebugData { name: "", ty: UInt<4> },
+                    value: 0x5,
+                },
+                6: CmpLt {
+                    dest: StatePartIndex<BigSlots>(15), // (0x1) SlotDebugData { name: "", ty: Bool },
+                    lhs: StatePartIndex<BigSlots>(14), // (0x5) SlotDebugData { name: "", ty: UInt<4> },
+                    rhs: StatePartIndex<BigSlots>(8), // (0xa) SlotDebugData { name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::i", ty: UInt<4> },
+                },
+                7: CastToUInt {
+                    dest: StatePartIndex<BigSlots>(13), // (0xe) SlotDebugData { name: "", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(10), // (-0x2) SlotDebugData { name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::i2", ty: SInt<2> },
+                    dest_width: 4,
+                },
+                // at: module-XXXXXXXXXX-2.rs:7:1
+                8: Copy {
+                    dest: StatePartIndex<BigSlots>(11), // (0xf) SlotDebugData { name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::o2", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(13), // (0xe) SlotDebugData { name: "", ty: UInt<4> },
+                },
+                // at: module-XXXXXXXXXX-2.rs:8:1
+                9: BranchIfZero {
+                    target: 11,
+                    value: StatePartIndex<BigSlots>(15), // (0x1) SlotDebugData { name: "", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX-2.rs:9:1
+                10: Copy {
+                    dest: StatePartIndex<BigSlots>(11), // (0xf) SlotDebugData { name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::o2", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(16), // (0xf) SlotDebugData { name: "", ty: UInt<4> },
+                },
+                // at: module-XXXXXXXXXX.rs:2:1
+                11: Copy {
+                    dest: StatePartIndex<BigSlots>(7), // (0xf) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::child.o2", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(11), // (0xf) SlotDebugData { name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::o2", ty: UInt<4> },
+                },
+                // at: module-XXXXXXXXXX.rs:4:1
+                12: Copy {
+                    dest: StatePartIndex<BigSlots>(3), // (0xf) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::o.o2", ty: UInt<4> },
+                    src: StatePartIndex<BigSlots>(7), // (0xf) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::child.o2", ty: UInt<4> },
+                },
+                // at: module-XXXXXXXXXX-2.rs:1:1
+                13: CastToSInt {
+                    dest: StatePartIndex<BigSlots>(12), // (-0x2) SlotDebugData { name: "", ty: SInt<2> },
+                    src: StatePartIndex<BigSlots>(8), // (0xa) SlotDebugData { name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::i", ty: UInt<4> },
+                    dest_width: 2,
+                },
+                // at: module-XXXXXXXXXX-2.rs:6:1
+                14: Copy {
+                    dest: StatePartIndex<BigSlots>(9), // (-0x2) SlotDebugData { name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::o", ty: SInt<2> },
+                    src: StatePartIndex<BigSlots>(12), // (-0x2) SlotDebugData { name: "", ty: SInt<2> },
+                },
+                // at: module-XXXXXXXXXX.rs:2:1
+                15: Copy {
+                    dest: StatePartIndex<BigSlots>(5), // (-0x2) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::child.o", ty: SInt<2> },
+                    src: StatePartIndex<BigSlots>(9), // (-0x2) SlotDebugData { name: "InstantiatedModule(mod1.child: mod1_child).mod1_child::o", ty: SInt<2> },
+                },
+                // at: module-XXXXXXXXXX.rs:4:1
+                16: Copy {
+                    dest: StatePartIndex<BigSlots>(1), // (-0x2) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::o.o", ty: SInt<2> },
+                    src: StatePartIndex<BigSlots>(5), // (-0x2) SlotDebugData { name: "InstantiatedModule(mod1: mod1).mod1::child.o", ty: SInt<2> },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                17: Return,
+            ],
+            ..
+        },
+        pc: 17,
+        memory_write_log: [],
+        memories: StatePart {
+            value: [],
+        },
+        small_slots: StatePart {
+            value: [],
+        },
+        big_slots: StatePart {
+            value: [
+                10,
+                -2,
+                -2,
+                15,
+                10,
+                -2,
+                -2,
+                15,
+                10,
+                -2,
+                -2,
+                15,
+                -2,
+                14,
+                5,
+                1,
+                15,
+            ],
+        },
+    },
+    io: Instance {
+        name: <simulator>::mod1,
+        instantiated: Module {
+            name: mod1,
+            ..
+        },
+    },
+    uninitialized_inputs: {},
+    io_targets: {
+        Instance {
+            name: <simulator>::mod1,
+            instantiated: Module {
+                name: mod1,
+                ..
+            },
+        }.o: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: Bundle {
+                    #[hdl(flip)] /* offset = 0 */
+                    i: UInt<4>,
+                    /* offset = 4 */
+                    o: SInt<2>,
+                    #[hdl(flip)] /* offset = 6 */
+                    i2: SInt<2>,
+                    /* offset = 8 */
+                    o2: UInt<4>,
+                },
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 4,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::o.i",
+                                ty: UInt<4>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::o.o",
+                                ty: SInt<2>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::o.i2",
+                                ty: SInt<2>,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(mod1: mod1).mod1::o.o2",
+                                ty: UInt<4>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Bundle {
+                    fields: [
+                        CompiledBundleField {
+                            offset: TypeIndex {
+                                small_slots: StatePartIndex<SmallSlots>(0),
+                                big_slots: StatePartIndex<BigSlots>(0),
+                            },
+                            ty: CompiledTypeLayout {
+                                ty: UInt<4>,
+                                layout: TypeLayout {
+                                    small_slots: StatePartLayout<SmallSlots> {
+                                        len: 0,
+                                        debug_data: [],
+                                        ..
+                                    },
+                                    big_slots: StatePartLayout<BigSlots> {
+                                        len: 1,
+                                        debug_data: [
+                                            SlotDebugData {
+                                                name: "",
+                                                ty: UInt<4>,
+                                            },
+                                        ],
+                                        ..
+                                    },
+                                },
+                                body: Scalar,
+                            },
+                        },
+                        CompiledBundleField {
+                            offset: TypeIndex {
+                                small_slots: StatePartIndex<SmallSlots>(0),
+                                big_slots: StatePartIndex<BigSlots>(1),
+                            },
+                            ty: CompiledTypeLayout {
+                                ty: SInt<2>,
+                                layout: TypeLayout {
+                                    small_slots: StatePartLayout<SmallSlots> {
+                                        len: 0,
+                                        debug_data: [],
+                                        ..
+                                    },
+                                    big_slots: StatePartLayout<BigSlots> {
+                                        len: 1,
+                                        debug_data: [
+                                            SlotDebugData {
+                                                name: "",
+                                                ty: SInt<2>,
+                                            },
+                                        ],
+                                        ..
+                                    },
+                                },
+                                body: Scalar,
+                            },
+                        },
+                        CompiledBundleField {
+                            offset: TypeIndex {
+                                small_slots: StatePartIndex<SmallSlots>(0),
+                                big_slots: StatePartIndex<BigSlots>(2),
+                            },
+                            ty: CompiledTypeLayout {
+                                ty: SInt<2>,
+                                layout: TypeLayout {
+                                    small_slots: StatePartLayout<SmallSlots> {
+                                        len: 0,
+                                        debug_data: [],
+                                        ..
+                                    },
+                                    big_slots: StatePartLayout<BigSlots> {
+                                        len: 1,
+                                        debug_data: [
+                                            SlotDebugData {
+                                                name: "",
+                                                ty: SInt<2>,
+                                            },
+                                        ],
+                                        ..
+                                    },
+                                },
+                                body: Scalar,
+                            },
+                        },
+                        CompiledBundleField {
+                            offset: TypeIndex {
+                                small_slots: StatePartIndex<SmallSlots>(0),
+                                big_slots: StatePartIndex<BigSlots>(3),
+                            },
+                            ty: CompiledTypeLayout {
+                                ty: UInt<4>,
+                                layout: TypeLayout {
+                                    small_slots: StatePartLayout<SmallSlots> {
+                                        len: 0,
+                                        debug_data: [],
+                                        ..
+                                    },
+                                    big_slots: StatePartLayout<BigSlots> {
+                                        len: 1,
+                                        debug_data: [
+                                            SlotDebugData {
+                                                name: "",
+                                                ty: UInt<4>,
+                                            },
+                                        ],
+                                        ..
+                                    },
+                                },
+                                body: Scalar,
+                            },
+                        },
+                    ],
+                },
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 0, len: 4 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::mod1,
+            instantiated: Module {
+                name: mod1,
+                ..
+            },
+        }.o.i: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: UInt<4>,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<4>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 0, len: 1 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::mod1,
+            instantiated: Module {
+                name: mod1,
+                ..
+            },
+        }.o.i2: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: SInt<2>,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: SInt<2>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 2, len: 1 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::mod1,
+            instantiated: Module {
+                name: mod1,
+                ..
+            },
+        }.o.o: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: SInt<2>,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: SInt<2>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 1, len: 1 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::mod1,
+            instantiated: Module {
+                name: mod1,
+                ..
+            },
+        }.o.o2: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: UInt<4>,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: UInt<4>,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 3, len: 1 },
+            },
+            write: None,
+        },
+    },
+    made_initial_step: true,
+    needs_settle: false,
+    trace_decls: TraceModule {
+        name: "mod1",
+        children: [
+            TraceModuleIO {
+                name: "o",
+                child: TraceBundle {
+                    name: "o",
+                    fields: [
+                        TraceUInt {
+                            location: TraceScalarId(0),
+                            name: "i",
+                            ty: UInt<4>,
+                            flow: Source,
+                        },
+                        TraceSInt {
+                            location: TraceScalarId(1),
+                            name: "o",
+                            ty: SInt<2>,
+                            flow: Sink,
+                        },
+                        TraceSInt {
+                            location: TraceScalarId(2),
+                            name: "i2",
+                            ty: SInt<2>,
+                            flow: Source,
+                        },
+                        TraceUInt {
+                            location: TraceScalarId(3),
+                            name: "o2",
+                            ty: UInt<4>,
+                            flow: Sink,
+                        },
+                    ],
+                    ty: Bundle {
+                        #[hdl(flip)] /* offset = 0 */
+                        i: UInt<4>,
+                        /* offset = 4 */
+                        o: SInt<2>,
+                        #[hdl(flip)] /* offset = 6 */
+                        i2: SInt<2>,
+                        /* offset = 8 */
+                        o2: UInt<4>,
+                    },
+                    flow: Sink,
+                },
+                ty: Bundle {
+                    #[hdl(flip)] /* offset = 0 */
+                    i: UInt<4>,
+                    /* offset = 4 */
+                    o: SInt<2>,
+                    #[hdl(flip)] /* offset = 6 */
+                    i2: SInt<2>,
+                    /* offset = 8 */
+                    o2: UInt<4>,
+                },
+                flow: Sink,
+            },
+            TraceInstance {
+                name: "child",
+                instance_io: TraceBundle {
+                    name: "child",
+                    fields: [
+                        TraceUInt {
+                            location: TraceScalarId(8),
+                            name: "i",
+                            ty: UInt<4>,
+                            flow: Sink,
+                        },
+                        TraceSInt {
+                            location: TraceScalarId(9),
+                            name: "o",
+                            ty: SInt<2>,
+                            flow: Source,
+                        },
+                        TraceSInt {
+                            location: TraceScalarId(10),
+                            name: "i2",
+                            ty: SInt<2>,
+                            flow: Sink,
+                        },
+                        TraceUInt {
+                            location: TraceScalarId(11),
+                            name: "o2",
+                            ty: UInt<4>,
+                            flow: Source,
+                        },
+                    ],
+                    ty: Bundle {
+                        #[hdl(flip)] /* offset = 0 */
+                        i: UInt<4>,
+                        /* offset = 4 */
+                        o: SInt<2>,
+                        #[hdl(flip)] /* offset = 6 */
+                        i2: SInt<2>,
+                        /* offset = 8 */
+                        o2: UInt<4>,
+                    },
+                    flow: Source,
+                },
+                module: TraceModule {
+                    name: "mod1_child",
+                    children: [
+                        TraceModuleIO {
+                            name: "i",
+                            child: TraceUInt {
+                                location: TraceScalarId(4),
+                                name: "i",
+                                ty: UInt<4>,
+                                flow: Source,
+                            },
+                            ty: UInt<4>,
+                            flow: Source,
+                        },
+                        TraceModuleIO {
+                            name: "o",
+                            child: TraceSInt {
+                                location: TraceScalarId(5),
+                                name: "o",
+                                ty: SInt<2>,
+                                flow: Sink,
+                            },
+                            ty: SInt<2>,
+                            flow: Sink,
+                        },
+                        TraceModuleIO {
+                            name: "i2",
+                            child: TraceSInt {
+                                location: TraceScalarId(6),
+                                name: "i2",
+                                ty: SInt<2>,
+                                flow: Source,
+                            },
+                            ty: SInt<2>,
+                            flow: Source,
+                        },
+                        TraceModuleIO {
+                            name: "o2",
+                            child: TraceUInt {
+                                location: TraceScalarId(7),
+                                name: "o2",
+                                ty: UInt<4>,
+                                flow: Sink,
+                            },
+                            ty: UInt<4>,
+                            flow: Sink,
+                        },
+                    ],
+                },
+                ty: Bundle {
+                    #[hdl(flip)] /* offset = 0 */
+                    i: UInt<4>,
+                    /* offset = 4 */
+                    o: SInt<2>,
+                    #[hdl(flip)] /* offset = 6 */
+                    i2: SInt<2>,
+                    /* offset = 8 */
+                    o2: UInt<4>,
+                },
+            },
+        ],
+    },
+    traces: [
+        SimTrace {
+            id: TraceScalarId(0),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(0),
+                ty: UInt<4>,
+            },
+            state: 0xa,
+            last_state: 0x3,
+        },
+        SimTrace {
+            id: TraceScalarId(1),
+            kind: BigSInt {
+                index: StatePartIndex<BigSlots>(1),
+                ty: SInt<2>,
+            },
+            state: 0x2,
+            last_state: 0x3,
+        },
+        SimTrace {
+            id: TraceScalarId(2),
+            kind: BigSInt {
+                index: StatePartIndex<BigSlots>(2),
+                ty: SInt<2>,
+            },
+            state: 0x2,
+            last_state: 0x2,
+        },
+        SimTrace {
+            id: TraceScalarId(3),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(3),
+                ty: UInt<4>,
+            },
+            state: 0xf,
+            last_state: 0xe,
+        },
+        SimTrace {
+            id: TraceScalarId(4),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(8),
+                ty: UInt<4>,
+            },
+            state: 0xa,
+            last_state: 0x3,
+        },
+        SimTrace {
+            id: TraceScalarId(5),
+            kind: BigSInt {
+                index: StatePartIndex<BigSlots>(9),
+                ty: SInt<2>,
+            },
+            state: 0x2,
+            last_state: 0x3,
+        },
+        SimTrace {
+            id: TraceScalarId(6),
+            kind: BigSInt {
+                index: StatePartIndex<BigSlots>(10),
+                ty: SInt<2>,
+            },
+            state: 0x2,
+            last_state: 0x2,
+        },
+        SimTrace {
+            id: TraceScalarId(7),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(11),
+                ty: UInt<4>,
+            },
+            state: 0xf,
+            last_state: 0xe,
+        },
+        SimTrace {
+            id: TraceScalarId(8),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(4),
+                ty: UInt<4>,
+            },
+            state: 0xa,
+            last_state: 0x3,
+        },
+        SimTrace {
+            id: TraceScalarId(9),
+            kind: BigSInt {
+                index: StatePartIndex<BigSlots>(5),
+                ty: SInt<2>,
+            },
+            state: 0x2,
+            last_state: 0x3,
+        },
+        SimTrace {
+            id: TraceScalarId(10),
+            kind: BigSInt {
+                index: StatePartIndex<BigSlots>(6),
+                ty: SInt<2>,
+            },
+            state: 0x2,
+            last_state: 0x2,
+        },
+        SimTrace {
+            id: TraceScalarId(11),
+            kind: BigUInt {
+                index: StatePartIndex<BigSlots>(7),
+                ty: UInt<4>,
+            },
+            state: 0xf,
+            last_state: 0xe,
+        },
+    ],
+    trace_memories: {},
+    trace_writers: [
+        Running(
+            VcdWriter {
+                finished_init: true,
+                timescale: 1 ps,
+                ..
+            },
+        ),
+    ],
+    instant: 2 μs,
+    clocks_triggered: [],
+    ..
+}

crates/fayalite/tests/sim/expected/mod1.vcd

@@ -0,0 +1,47 @@
+$timescale 1 ps $end
+$scope module mod1 $end
+$scope struct o $end
+$var wire 4 ! i $end
+$var wire 2 " o $end
+$var wire 2 # i2 $end
+$var wire 4 $ o2 $end
+$upscope $end
+$scope struct child $end
+$var wire 4 ) i $end
+$var wire 2 * o $end
+$var wire 2 + i2 $end
+$var wire 4 , o2 $end
+$upscope $end
+$scope module mod1_child $end
+$var wire 4 % i $end
+$var wire 2 & o $end
+$var wire 2 ' i2 $end
+$var wire 4 ( o2 $end
+$upscope $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+b11 !
+b11 "
+b10 #
+b1110 $
+b11 %
+b11 &
+b10 '
+b1110 (
+b11 )
+b11 *
+b10 +
+b1110 ,
+$end
+#1000000
+b1010 !
+b10 "
+b1111 $
+b1010 %
+b10 &
+b1111 (
+b1010 )
+b10 *
+b1111 ,
+#2000000

crates/fayalite/tests/sim/expected/shift_register.txt

@@ -0,0 +1,683 @@
+Simulation {
+    state: State {
+        insns: Insns {
+            state_layout: StateLayout {
+                ty: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 4,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                        ],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 13,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::cd.clk",
+                                ty: Clock,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::cd.rst",
+                                ty: SyncReset,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::d",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::q",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::reg0",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::reg0$next",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::reg1",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::reg1$next",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::reg2",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::reg2$next",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::reg3",
+                                ty: Bool,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::reg3$next",
+                                ty: Bool,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                memories: StatePartLayout<Memories> {
+                    len: 0,
+                    debug_data: [],
+                    layout_data: [],
+                    ..
+                },
+            },
+            insns: [
+                // at: module-XXXXXXXXXX.rs:13:1
+                0: Copy {
+                    dest: StatePartIndex<BigSlots>(3), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::q", ty: Bool },
+                    src: StatePartIndex<BigSlots>(11), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg3", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:12:1
+                1: Copy {
+                    dest: StatePartIndex<BigSlots>(12), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg3$next", ty: Bool },
+                    src: StatePartIndex<BigSlots>(9), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg2", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:10:1
+                2: Copy {
+                    dest: StatePartIndex<BigSlots>(10), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg2$next", ty: Bool },
+                    src: StatePartIndex<BigSlots>(7), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg1", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:8:1
+                3: Copy {
+                    dest: StatePartIndex<BigSlots>(8), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg1$next", ty: Bool },
+                    src: StatePartIndex<BigSlots>(4), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg0", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:6:1
+                4: Copy {
+                    dest: StatePartIndex<BigSlots>(5), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg0$next", ty: Bool },
+                    src: StatePartIndex<BigSlots>(2), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::d", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:5:1
+                5: IsNonZeroDestIsSmall {
+                    dest: StatePartIndex<SmallSlots>(3), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                    src: StatePartIndex<BigSlots>(1), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::cd.rst", ty: SyncReset },
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                6: Const {
+                    dest: StatePartIndex<BigSlots>(6), // (0x0) SlotDebugData { name: "", ty: Bool },
+                    value: 0x0,
+                },
+                // at: module-XXXXXXXXXX.rs:5:1
+                7: IsNonZeroDestIsSmall {
+                    dest: StatePartIndex<SmallSlots>(2), // (0x1 1) SlotDebugData { name: "", ty: Bool },
+                    src: StatePartIndex<BigSlots>(0), // (0x1) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::cd.clk", ty: Clock },
+                },
+                8: AndSmall {
+                    dest: StatePartIndex<SmallSlots>(1), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                    lhs: StatePartIndex<SmallSlots>(2), // (0x1 1) SlotDebugData { name: "", ty: Bool },
+                    rhs: StatePartIndex<SmallSlots>(0), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                9: BranchIfSmallZero {
+                    target: 14,
+                    value: StatePartIndex<SmallSlots>(1), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                10: BranchIfSmallNonZero {
+                    target: 13,
+                    value: StatePartIndex<SmallSlots>(3), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                11: Copy {
+                    dest: StatePartIndex<BigSlots>(4), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg0", ty: Bool },
+                    src: StatePartIndex<BigSlots>(5), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg0$next", ty: Bool },
+                },
+                12: Branch {
+                    target: 14,
+                },
+                13: Copy {
+                    dest: StatePartIndex<BigSlots>(4), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg0", ty: Bool },
+                    src: StatePartIndex<BigSlots>(6), // (0x0) SlotDebugData { name: "", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:7:1
+                14: BranchIfSmallZero {
+                    target: 19,
+                    value: StatePartIndex<SmallSlots>(1), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                15: BranchIfSmallNonZero {
+                    target: 18,
+                    value: StatePartIndex<SmallSlots>(3), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                16: Copy {
+                    dest: StatePartIndex<BigSlots>(7), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg1", ty: Bool },
+                    src: StatePartIndex<BigSlots>(8), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg1$next", ty: Bool },
+                },
+                17: Branch {
+                    target: 19,
+                },
+                18: Copy {
+                    dest: StatePartIndex<BigSlots>(7), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg1", ty: Bool },
+                    src: StatePartIndex<BigSlots>(6), // (0x0) SlotDebugData { name: "", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:9:1
+                19: BranchIfSmallZero {
+                    target: 24,
+                    value: StatePartIndex<SmallSlots>(1), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                20: BranchIfSmallNonZero {
+                    target: 23,
+                    value: StatePartIndex<SmallSlots>(3), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                21: Copy {
+                    dest: StatePartIndex<BigSlots>(9), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg2", ty: Bool },
+                    src: StatePartIndex<BigSlots>(10), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg2$next", ty: Bool },
+                },
+                22: Branch {
+                    target: 24,
+                },
+                23: Copy {
+                    dest: StatePartIndex<BigSlots>(9), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg2", ty: Bool },
+                    src: StatePartIndex<BigSlots>(6), // (0x0) SlotDebugData { name: "", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:11:1
+                24: BranchIfSmallZero {
+                    target: 29,
+                    value: StatePartIndex<SmallSlots>(1), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                25: BranchIfSmallNonZero {
+                    target: 28,
+                    value: StatePartIndex<SmallSlots>(3), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                },
+                26: Copy {
+                    dest: StatePartIndex<BigSlots>(11), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg3", ty: Bool },
+                    src: StatePartIndex<BigSlots>(12), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg3$next", ty: Bool },
+                },
+                27: Branch {
+                    target: 29,
+                },
+                28: Copy {
+                    dest: StatePartIndex<BigSlots>(11), // (0x0) SlotDebugData { name: "InstantiatedModule(shift_register: shift_register).shift_register::reg3", ty: Bool },
+                    src: StatePartIndex<BigSlots>(6), // (0x0) SlotDebugData { name: "", ty: Bool },
+                },
+                // at: module-XXXXXXXXXX.rs:5:1
+                29: XorSmallImmediate {
+                    dest: StatePartIndex<SmallSlots>(0), // (0x0 0) SlotDebugData { name: "", ty: Bool },
+                    lhs: StatePartIndex<SmallSlots>(2), // (0x1 1) SlotDebugData { name: "", ty: Bool },
+                    rhs: 0x1,
+                },
+                // at: module-XXXXXXXXXX.rs:1:1
+                30: Return,
+            ],
+            ..
+        },
+        pc: 30,
+        memory_write_log: [],
+        memories: StatePart {
+            value: [],
+        },
+        small_slots: StatePart {
+            value: [
+                0,
+                0,
+                1,
+                0,
+            ],
+        },
+        big_slots: StatePart {
+            value: [
+                1,
+                0,
+                0,
+                0,
+                0,
+                0,
+                0,
+                0,
+                0,
+                0,
+                0,
+                0,
+                0,
+            ],
+        },
+    },
+    io: Instance {
+        name: <simulator>::shift_register,
+        instantiated: Module {
+            name: shift_register,
+            ..
+        },
+    },
+    uninitialized_inputs: {},
+    io_targets: {
+        Instance {
+            name: <simulator>::shift_register,
+            instantiated: Module {
+                name: shift_register,
+                ..
+            },
+        }.cd: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: Bundle {
+                    /* offset = 0 */
+                    clk: Clock,
+                    /* offset = 1 */
+                    rst: SyncReset,
+                },
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 2,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::cd.clk",
+                                ty: Clock,
+                            },
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::cd.rst",
+                                ty: SyncReset,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Bundle {
+                    fields: [
+                        CompiledBundleField {
+                            offset: TypeIndex {
+                                small_slots: StatePartIndex<SmallSlots>(0),
+                                big_slots: StatePartIndex<BigSlots>(0),
+                            },
+                            ty: CompiledTypeLayout {
+                                ty: Clock,
+                                layout: TypeLayout {
+                                    small_slots: StatePartLayout<SmallSlots> {
+                                        len: 0,
+                                        debug_data: [],
+                                        ..
+                                    },
+                                    big_slots: StatePartLayout<BigSlots> {
+                                        len: 1,
+                                        debug_data: [
+                                            SlotDebugData {
+                                                name: "",
+                                                ty: Clock,
+                                            },
+                                        ],
+                                        ..
+                                    },
+                                },
+                                body: Scalar,
+                            },
+                        },
+                        CompiledBundleField {
+                            offset: TypeIndex {
+                                small_slots: StatePartIndex<SmallSlots>(0),
+                                big_slots: StatePartIndex<BigSlots>(1),
+                            },
+                            ty: CompiledTypeLayout {
+                                ty: SyncReset,
+                                layout: TypeLayout {
+                                    small_slots: StatePartLayout<SmallSlots> {
+                                        len: 0,
+                                        debug_data: [],
+                                        ..
+                                    },
+                                    big_slots: StatePartLayout<BigSlots> {
+                                        len: 1,
+                                        debug_data: [
+                                            SlotDebugData {
+                                                name: "",
+                                                ty: SyncReset,
+                                            },
+                                        ],
+                                        ..
+                                    },
+                                },
+                                body: Scalar,
+                            },
+                        },
+                    ],
+                },
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 0, len: 2 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::shift_register,
+            instantiated: Module {
+                name: shift_register,
+                ..
+            },
+        }.cd.clk: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: Clock,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: Clock,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 0, len: 1 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::shift_register,
+            instantiated: Module {
+                name: shift_register,
+                ..
+            },
+        }.cd.rst: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: SyncReset,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "",
+                                ty: SyncReset,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 1, len: 1 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::shift_register,
+            instantiated: Module {
+                name: shift_register,
+                ..
+            },
+        }.d: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: Bool,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::d",
+                                ty: Bool,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 2, len: 1 },
+            },
+            write: None,
+        },
+        Instance {
+            name: <simulator>::shift_register,
+            instantiated: Module {
+                name: shift_register,
+                ..
+            },
+        }.q: CompiledValue {
+            layout: CompiledTypeLayout {
+                ty: Bool,
+                layout: TypeLayout {
+                    small_slots: StatePartLayout<SmallSlots> {
+                        len: 0,
+                        debug_data: [],
+                        ..
+                    },
+                    big_slots: StatePartLayout<BigSlots> {
+                        len: 1,
+                        debug_data: [
+                            SlotDebugData {
+                                name: "InstantiatedModule(shift_register: shift_register).shift_register::q",
+                                ty: Bool,
+                            },
+                        ],
+                        ..
+                    },
+                },
+                body: Scalar,
+            },
+            range: TypeIndexRange {
+                small_slots: StatePartIndexRange<SmallSlots> { start: 0, len: 0 },
+                big_slots: StatePartIndexRange<BigSlots> { start: 3, len: 1 },
+            },
+            write: None,
+        },
+    },
+    made_initial_step: true,
+    needs_settle: false,
+    trace_decls: TraceModule {
+        name: "shift_register",
+        children: [
+            TraceModuleIO {
+                name: "cd",
+                child: TraceBundle {
+                    name: "cd",
+                    fields: [
+                        TraceClock {
+                            location: TraceScalarId(0),
+                            name: "clk",
+                            flow: Source,
+                        },
+                        TraceSyncReset {
+                            location: TraceScalarId(1),
+                            name: "rst",
+                            flow: Source,
+                        },
+                    ],
+                    ty: Bundle {
+                        /* offset = 0 */
+                        clk: Clock,
+                        /* offset = 1 */
+                        rst: SyncReset,
+                    },
+                    flow: Source,
+                },
+                ty: Bundle {
+                    /* offset = 0 */
+                    clk: Clock,
+                    /* offset = 1 */
+                    rst: SyncReset,
+                },
+                flow: Source,
+            },
+            TraceModuleIO {
+                name: "d",
+                child: TraceBool {
+                    location: TraceScalarId(2),
+                    name: "d",
+                    flow: Source,
+                },
+                ty: Bool,
+                flow: Source,
+            },
+            TraceModuleIO {
+                name: "q",
+                child: TraceBool {
+                    location: TraceScalarId(3),
+                    name: "q",
+                    flow: Sink,
+                },
+                ty: Bool,
+                flow: Sink,
+            },
+            TraceReg {
+                name: "reg0",
+                child: TraceBool {
+                    location: TraceScalarId(4),
+                    name: "reg0",
+                    flow: Duplex,
+                },
+                ty: Bool,
+            },
+            TraceReg {
+                name: "reg1",
+                child: TraceBool {
+                    location: TraceScalarId(5),
+                    name: "reg1",
+                    flow: Duplex,
+                },
+                ty: Bool,
+            },
+            TraceReg {
+                name: "reg2",
+                child: TraceBool {
+                    location: TraceScalarId(6),
+                    name: "reg2",
+                    flow: Duplex,
+                },
+                ty: Bool,
+            },
+            TraceReg {
+                name: "reg3",
+                child: TraceBool {
+                    location: TraceScalarId(7),
+                    name: "reg3",
+                    flow: Duplex,
+                },
+                ty: Bool,
+            },
+        ],
+    },
+    traces: [
+        SimTrace {
+            id: TraceScalarId(0),
+            kind: BigClock {
+                index: StatePartIndex<BigSlots>(0),
+            },
+            state: 0x1,
+            last_state: 0x1,
+        },
+        SimTrace {
+            id: TraceScalarId(1),
+            kind: BigSyncReset {
+                index: StatePartIndex<BigSlots>(1),
+            },
+            state: 0x0,
+            last_state: 0x0,
+        },
+        SimTrace {
+            id: TraceScalarId(2),
+            kind: BigBool {
+                index: StatePartIndex<BigSlots>(2),
+            },
+            state: 0x0,
+            last_state: 0x0,
+        },
+        SimTrace {
+            id: TraceScalarId(3),
+            kind: BigBool {
+                index: StatePartIndex<BigSlots>(3),
+            },
+            state: 0x0,
+            last_state: 0x0,
+        },
+        SimTrace {
+            id: TraceScalarId(4),
+            kind: BigBool {
+                index: StatePartIndex<BigSlots>(4),
+            },
+            state: 0x0,
+            last_state: 0x0,
+        },
+        SimTrace {
+            id: TraceScalarId(5),
+            kind: BigBool {
+                index: StatePartIndex<BigSlots>(7),
+            },
+            state: 0x0,
+            last_state: 0x0,
+        },
+        SimTrace {
+            id: TraceScalarId(6),
+            kind: BigBool {
+                index: StatePartIndex<BigSlots>(9),
+            },
+            state: 0x0,
+            last_state: 0x0,
+        },
+        SimTrace {
+            id: TraceScalarId(7),
+            kind: BigBool {
+                index: StatePartIndex<BigSlots>(11),
+            },
+            state: 0x0,
+            last_state: 0x0,
+        },
+    ],
+    trace_memories: {},
+    trace_writers: [
+        Running(
+            VcdWriter {
+                finished_init: true,
+                timescale: 1 ps,
+                ..
+            },
+        ),
+    ],
+    instant: 66 μs,
+    clocks_triggered: [
+        StatePartIndex<SmallSlots>(1),
+    ],
+    ..
+}

crates/fayalite/tests/sim/expected/shift_register.vcd

@@ -0,0 +1,193 @@
+$timescale 1 ps $end
+$scope module shift_register $end
+$scope struct cd $end
+$var wire 1 ! clk $end
+$var wire 1 " rst $end
+$upscope $end
+$var wire 1 # d $end
+$var wire 1 $ q $end
+$var reg 1 % reg0 $end
+$var reg 1 & reg1 $end
+$var reg 1 ' reg2 $end
+$var reg 1 ( reg3 $end
+$upscope $end
+$enddefinitions $end
+$dumpvars
+0!
+1"
+0#
+0$
+0%
+0&
+0'
+0(
+$end
+#1000000
+1!
+#1100000
+0"
+#2000000
+0!
+#3000000
+1!
+#4000000
+0!
+1#
+#5000000
+1!
+1%
+#6000000
+0!
+#7000000
+1!
+1&
+#8000000
+0!
+0#
+#9000000
+1!
+0%
+1'
+#10000000
+0!
+#11000000
+1!
+0&
+1(
+1$
+#12000000
+0!
+1#
+#13000000
+1!
+1%
+0'
+#14000000
+0!
+0#
+#15000000
+1!
+0%
+1&
+0(
+0$
+#16000000
+0!
+1#
+#17000000
+1!
+1%
+0&
+1'
+#18000000
+0!
+#19000000
+1!
+1&
+0'
+1(
+1$
+#20000000
+0!
+#21000000
+1!
+1'
+0(
+0$
+#22000000
+0!
+#23000000
+1!
+1(
+1$
+#24000000
+0!
+0#
+#25000000
+1!
+0%
+#26000000
+0!
+#27000000
+1!
+0&
+#28000000
+0!
+#29000000
+1!
+0'
+#30000000
+0!
+#31000000
+1!
+0(
+0$
+#32000000
+0!
+#33000000
+1!
+#34000000
+0!
+#35000000
+1!
+#36000000
+0!
+#37000000
+1!
+#38000000
+0!
+#39000000
+1!
+#40000000
+0!
+#41000000
+1!
+#42000000
+0!
+#43000000
+1!
+#44000000
+0!
+#45000000
+1!
+#46000000
+0!
+#47000000
+1!
+#48000000
+0!
+#49000000
+1!
+#50000000
+0!
+#51000000
+1!
+#52000000
+0!
+#53000000
+1!
+#54000000
+0!
+#55000000
+1!
+#56000000
+0!
+#57000000
+1!
+#58000000
+0!
+#59000000
+1!
+#60000000
+0!
+#61000000
+1!
+#62000000
+0!
+#63000000
+1!
+#64000000
+0!
+#65000000
+1!
+#66000000

crates/fayalite/visit_types.json

@@ -1047,9 +1047,9 @@
                 "clock_domain()": "Visible",
                 "init()": "Visible"
             },
-            "generics": "<T: Type>",
+            "generics": "<T: Type, R: ResetType>",
-            "fold_where": "T: Fold<State>",
+            "fold_where": "T: Fold<State>, R: Fold<State>",
-            "visit_where": "T: Visit<State>"
+            "visit_where": "T: Visit<State>, R: Visit<State>"
         },
         "Wire": {
             "data": {
@@ -1078,6 +1078,8 @@
                 "$kind": "Enum",
                 "Wire": "Visible",
                 "Reg": "Visible",
+                "RegSync": "Visible",
+                "RegAsync": "Visible",
                 "Instance": "Visible"
             }
         },
@@ -1136,7 +1138,10 @@
                 "$kind": "Struct",
                 "annotations": "Visible",
                 "reg": "Visible"
-            }
+            },
+            "generics": "<R: ResetType>",
+            "fold_where": "R: Fold<State>",
+            "visit_where": "R: Visit<State>"
         },
         "StmtWire": {
             "data": {
@@ -1219,6 +1224,8 @@
                 "ModuleIO": "Visible",
                 "MemPort": "Visible",
                 "Reg": "Visible",
+                "RegSync": "Visible",
+                "RegAsync": "Visible",
                 "Wire": "Visible",
                 "Instance": "Visible"
             }

scripts/check-copyright.sh

@@ -46,7 +46,7 @@ function main()
         */LICENSE.md|*/Notices.txt)
             # copyright file
             ;;
-        /crates/fayalite/tests/ui/*.stderr)
+        /crates/fayalite/tests/ui/*.stderr|/crates/fayalite/tests/sim/expected/*.vcd|/crates/fayalite/tests/sim/expected/*.txt)
             # file that can't contain copyright header
             ;;
         /.forgejo/workflows/*.yml|*/.gitignore|*.toml)