unit::alu_branch: implement for ShiftRotateMOp; TODO: flags and shift amount overflow

crates/cpu/src/unit/alu_branch.rs

@@ -6,7 +6,8 @@ use crate::{
     instruction::{
         AddSubMOp, AluBranchMOp, AluCommonMOp, BranchMOp, COMMON_MOP_SRC_LEN, CommonMOp,
         CommonMOpDefaultImm, CompareMOp, CompareMode, ConditionMode, LogicalFlagsMOp, LogicalMOp,
-        OutputIntegerMode, PRegNum, ReadSpecialMOp, ShiftRotateMOp,
+        OutputIntegerMode, PRegNum, ReadSpecialMOp, ShiftRotateDestLogicOp, ShiftRotateMOp,
+        ShiftRotateMOpImm, ShiftRotateMode,
     },
     next_pc::CallStackOp,
     register::{
@@ -280,17 +281,227 @@ fn logical_i<C: PhantomConstCpuConfig>(
     PRegValue::zeroed().to_trace_as_string()
 }
 
+#[hdl]
+fn funnel_shift<W: Size, A: Size>(
+    high: impl ToExpr<Type = UIntType<W>>,
+    low: impl ToExpr<Type = UIntType<W>>,
+    shift_right: impl ToExpr<Type = Bool>,
+    shift_amount: impl ToExpr<Type = UIntType<A>>,
+) -> Expr<UIntType<W>> {
+    let high = high.to_expr();
+    let low = low.to_expr();
+    let shift_right = shift_right.to_expr();
+    let shift_amount = shift_amount.to_expr();
+    let int_ty = high.ty();
+    assert_eq!(int_ty, low.ty());
+    #[hdl]
+    let funnel_shift_high = wire(int_ty);
+    connect(funnel_shift_high, high);
+    #[hdl]
+    let funnel_shift_low = wire(int_ty);
+    connect(funnel_shift_low, low);
+    #[hdl]
+    let funnel_shift_right = wire();
+    connect(funnel_shift_right, shift_right);
+    #[hdl]
+    let funnel_shift_amount = wire(
+        UInt[shift_amount
+            .ty()
+            .width()
+            .min(UInt::range_usize(0..int_ty.width()).width())],
+    );
+    connect_any(funnel_shift_amount, shift_amount);
+    #[hdl]
+    let funnel_shift_reverse_amount = wire(funnel_shift_amount.ty());
+    connect_any(
+        funnel_shift_reverse_amount,
+        int_ty.width() - funnel_shift_amount,
+    );
+    #[hdl]
+    let funnel_shift_high_left_amount = wire(funnel_shift_amount.ty());
+    #[hdl]
+    let funnel_shift_low_right_amount = wire(funnel_shift_amount.ty());
+    #[hdl]
+    let funnel_shift_retval = wire(int_ty);
+    connect_any(
+        funnel_shift_retval,
+        (funnel_shift_high << funnel_shift_high_left_amount)
+            | (funnel_shift_low >> funnel_shift_low_right_amount),
+    );
+    #[hdl]
+    if funnel_shift_right {
+        connect(funnel_shift_high_left_amount, funnel_shift_reverse_amount);
+        connect(funnel_shift_low_right_amount, funnel_shift_amount);
+        #[hdl]
+        if shift_amount.cmp_eq(0u8) {
+            connect(funnel_shift_retval, funnel_shift_low);
+        }
+    } else {
+        connect(funnel_shift_high_left_amount, funnel_shift_amount);
+        connect(funnel_shift_low_right_amount, funnel_shift_reverse_amount);
+        #[hdl]
+        if shift_amount.cmp_eq(0u8) {
+            connect(funnel_shift_retval, funnel_shift_high);
+        }
+    }
+    funnel_shift_retval
+}
+
 #[hdl]
 fn shift_rotate<C: PhantomConstCpuConfig>(
     global_state: Expr<GlobalState>,
-    pc: Expr<UInt<64>>,
     mop: Expr<ShiftRotateMOp<PRegNum<C>, PRegNum<C>>>,
     src_values: Expr<Array<TraceAsString<PRegValue>, { COMMON_MOP_SRC_LEN }>>,
 ) -> Expr<TraceAsString<PRegValue>> {
     #[hdl]
     let GlobalState { flags_mode } = global_state;
-    // TODO: finish
-    PRegValue::zeroed().to_trace_as_string()
+    #[hdl]
+    let ShiftRotateMOp::<_, _> { alu_common, mode } = mop;
+    #[hdl]
+    let AluCommonMOp::<_, _, _, _> {
+        common,
+        output_integer_mode,
+    } = alu_common;
+    #[hdl]
+    let ShiftRotateMOpImm {
+        shift_rotate_amount: shift_rotate_amount_opt,
+        shift_rotate_right,
+        shift_amount_overflow_behavior,
+        dest_logic_op,
+    } = common.imm;
+    #[hdl]
+    let shift_rotate_amount = wire();
+    #[hdl]
+    match shift_rotate_amount_opt {
+        HdlSome(shift_rotate_amount_opt) => connect(
+            shift_rotate_amount,
+            shift_rotate_amount_opt.cast_to_static::<UInt<64>>(),
+        ),
+        HdlNone => connect(shift_rotate_amount, src_values[2].int_fp),
+    }
+    #[hdl]
+    let funnel_shift_2x64_high: UInt<64> = wire();
+    #[hdl]
+    let funnel_shift_2x64_low: UInt<64> = wire();
+    #[hdl]
+    let funnel_shift_2x64_amount = wire(UInt::range_usize(0..funnel_shift_2x64_high.ty().width()));
+    #[hdl]
+    let funnel_shift_2x64_output: UInt<64> = wire();
+    connect(
+        funnel_shift_2x64_output,
+        funnel_shift(
+            funnel_shift_2x64_high,
+            funnel_shift_2x64_low,
+            shift_rotate_right,
+            funnel_shift_2x64_amount,
+        ),
+    );
+    #[hdl]
+    let shifted_rotated: UInt<64> = wire();
+    let excess_bits_for_2x64 = |width| funnel_shift_2x64_low.ty().width() - width;
+    let connect_for_funnel_shift = |width| {
+        // TODO: handle large shift_rotate_amount >= width
+        connect(
+            funnel_shift_2x64_high,
+            src_values[0]
+                .int_fp
+                .cast_to(UInt[width])
+                .cast_to_static::<UInt<64>>(),
+        );
+        connect_any(
+            funnel_shift_2x64_low,
+            src_values[1].int_fp.cast_to(UInt[width]) << excess_bits_for_2x64(width),
+        );
+        connect_any(funnel_shift_2x64_amount, shift_rotate_amount);
+        #[hdl]
+        if shift_rotate_right {
+            connect_any(
+                shifted_rotated,
+                funnel_shift_2x64_output >> excess_bits_for_2x64(8),
+            );
+        } else {
+            connect(
+                shifted_rotated,
+                funnel_shift_2x64_output
+                    .cast_to(UInt[width])
+                    .cast_to_static::<UInt<64>>(),
+            );
+        }
+    };
+    let connect_for_sign_ext_then_shift = |width| {
+        // TODO: handle large shift_rotate_amount >= 64
+        let input = src_values[0]
+            .int_fp
+            .cast_to(SInt[width])
+            .cast_to_static::<SInt<64>>();
+        let input_sign_bit = input >> (input.ty().width() - 1);
+        #[hdl]
+        if shift_rotate_right {
+            connect(funnel_shift_2x64_high, input_sign_bit.cast_to_static());
+            connect(funnel_shift_2x64_low, input.cast_to_static());
+            connect_any(funnel_shift_2x64_amount, shift_rotate_amount);
+            connect(shifted_rotated, funnel_shift_2x64_output);
+        } else {
+            connect(funnel_shift_2x64_high, input.cast_to_static());
+            connect(funnel_shift_2x64_low, 0u64);
+            connect_any(funnel_shift_2x64_amount, shift_rotate_amount);
+            connect(shifted_rotated, funnel_shift_2x64_output);
+        }
+    };
+    #[hdl]
+    match mode {
+        ShiftRotateMode::FunnelShift2x8Bit => connect_for_funnel_shift(8),
+        ShiftRotateMode::FunnelShift2x16Bit => connect_for_funnel_shift(16),
+        ShiftRotateMode::FunnelShift2x32Bit => connect_for_funnel_shift(32),
+        ShiftRotateMode::FunnelShift2x64Bit => connect_for_funnel_shift(64),
+        ShiftRotateMode::SignExt8To64BitThenShift => connect_for_sign_ext_then_shift(8),
+        ShiftRotateMode::SignExt16To64BitThenShift => connect_for_sign_ext_then_shift(16),
+        ShiftRotateMode::SignExt32To64BitThenShift => connect_for_sign_ext_then_shift(32),
+        ShiftRotateMode::ShiftSigned64 => connect_for_sign_ext_then_shift(64),
+    }
+    #[hdl]
+    let masked: UInt<64> = wire();
+    #[hdl]
+    if let HdlSome(dest_logic_op) = dest_logic_op {
+        connect(
+            masked,
+            ShiftRotateDestLogicOp::operation(dest_logic_op, shifted_rotated, src_values[2].int_fp),
+        );
+    } else {
+        connect(masked, shifted_rotated);
+    }
+    #[hdl]
+    let int_fp: UInt<64> = wire();
+    fn connect_int_fp_cast<T: IntType + StaticType>(int_fp: Expr<UInt<64>>, masked: Expr<UInt<64>>)
+    where
+        UInt<64>: CastToImpl<T>,
+        T: CastToImpl<UInt<64>>,
+    {
+        connect(
+            int_fp,
+            masked.cast_to_static::<T>().cast_to_static::<UInt<64>>(),
+        )
+    }
+    #[hdl]
+    match output_integer_mode {
+        OutputIntegerMode::Full64 => connect(int_fp, masked),
+        OutputIntegerMode::DupLow32 => connect_any(
+            int_fp,
+            masked.cast_to_static::<UInt<32>>() | (masked.cast_to_static::<UInt<32>>() << 32),
+        ),
+        OutputIntegerMode::ZeroExt32 => connect_int_fp_cast::<UInt<32>>(int_fp, masked),
+        OutputIntegerMode::SignExt32 => connect_int_fp_cast::<SInt<32>>(int_fp, masked),
+        OutputIntegerMode::ZeroExt16 => connect_int_fp_cast::<UInt<16>>(int_fp, masked),
+        OutputIntegerMode::SignExt16 => connect_int_fp_cast::<SInt<16>>(int_fp, masked),
+        OutputIntegerMode::ZeroExt8 => connect_int_fp_cast::<UInt<8>>(int_fp, masked),
+        OutputIntegerMode::SignExt8 => connect_int_fp_cast::<SInt<8>>(int_fp, masked),
+    }
+    let retval = #[hdl]
+    PRegValue {
+        int_fp,
+        flags: PRegFlags::zeroed(), // TODO: compute flags
+    };
+    retval.into_trace_as_string()
 }
 
 #[hdl]
@@ -703,10 +914,7 @@ pub fn alu_branch(config: PhantomConst<CpuConfig>, unit_index: usize) {
                         );
                     }
                     AluBranchMOp::<_, _>::ShiftRotate(mop) => {
-                        connect(
-                            dest_value,
-                            shift_rotate(global_state, mop_instance.pc, mop, src_values),
-                        );
+                        connect(dest_value, shift_rotate(global_state, mop, src_values));
                     }
                     AluBranchMOp::<_, _>::Compare(mop) => {
                         connect(dest_value, compare(global_state, mop, src_values));

crates/cpu/tests/rename_execute_retire.rs

@@ -1642,7 +1642,7 @@ macro_rules! impl_funnel_shift {
             }
             fn funnel_shr(high: Self, low: Self, shift: u32) -> Self {
                 if shift == 0 {
-                    high
+                    low
                 } else {
                     (high << ($ty::BITS - shift)) | (low >> shift)
                 }
@@ -4585,6 +4585,42 @@ fn test_rename_execute_retire_head_n1() {
     assert!(sim.read_bool(sim.io().all_outputs_written));
 }
 
+#[hdl]
+#[test]
+fn test_rename_execute_retire_head_n1_real() {
+    let _n = SourceLocation::normalize_files_for_tests();
+    let mut config = CpuConfig::new(
+        vec![
+            UnitConfig::new(UnitKind::AluBranch),
+            UnitConfig::new(UnitKind::AluBranch),
+            UnitConfig::new(UnitKind::LoadStore),
+            UnitConfig::new(UnitKind::TransformedMove),
+        ],
+        NonZeroUsize::new(20).unwrap(),
+    );
+    config.fetch_width = NonZeroUsize::new(2).unwrap();
+    let m = rename_execute_retire_test_harness::<HeadN1Insns>(
+        PhantomConst::new_sized(config),
+        AluBranchKind::Real,
+    );
+    let mut sim = Simulation::new(m);
+    let _checked_vcd_output = checked_vcd_output!(
+        &mut sim,
+        "tests/expected/rename_execute_retire_head_n1_real.vcd",
+    );
+    sim.write_clock(sim.io().cd.clk, false);
+    sim.write_reset(sim.io().cd.rst, true);
+    for cycle in 0..300 {
+        sim.advance_time(SimDuration::from_nanos(500));
+        println!("clock tick: {cycle}");
+        sim.write_clock(sim.io().cd.clk, true);
+        sim.advance_time(SimDuration::from_nanos(500));
+        sim.write_clock(sim.io().cd.clk, false);
+        sim.write_reset(sim.io().cd.rst, false);
+    }
+    assert!(sim.read_bool(sim.io().all_outputs_written));
+}
+
 struct SaveRestoreGprsInsns;
 
 impl SaveRestoreGprsInsns {