From fb4f567456b24c820942fe8545470433fe7eb2c1 Mon Sep 17 00:00:00 2001
From: "Emil J. Tywoniak" <emil@tywoniak.eu>
Date: Mon, 22 Jun 2026 00:29:11 +0200
Subject: [PATCH] twine: auto type WIP

---
 kernel/rtlil.cc       | 23 ++++++++++++++++-------
 kernel/twine.h        | 17 ++++++++++++++++-
 kernel/yosys_common.h |  8 ++++----
 3 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/kernel/rtlil.cc b/kernel/rtlil.cc
index 0e99bd8f7..0c0bd6b32 100644
--- a/kernel/rtlil.cc
+++ b/kernel/rtlil.cc
@@ -3809,15 +3809,24 @@ RTLIL::Cell *RTLIL::Module::addCell(Twine name, Twine type)
 
 RTLIL::Cell *RTLIL::Module::addCell(TwineRef name, const RTLIL::Cell *other)
 {
-	RTLIL::Cell *cell = addCell(name, other->type_impl);
-	cell->connections_ = other->connections_;
+	const RTLIL::Design *src_design = other->module ? other->module->design : nullptr;
+	bool cross_pool = src_design && this->design && src_design != this->design;
+
+	TwineRef type = other->type_impl;
+	if (cross_pool)
+		type = this->design->twines.copy_from(src_design->twines, other->type_impl);
+
+	RTLIL::Cell *cell = addCell(name, type);
+	if (cross_pool) {
+		for (auto &c : other->connections_)
+			cell->connections_[this->design->twines.copy_from(src_design->twines, c.first)] = c.second;
+	} else {
+		cell->connections_ = other->connections_;
+	}
 	cell->parameters = other->parameters;
 	cell->attributes = other->attributes;
-	{
-		const RTLIL::Design *src_design = other->module ? other->module->design : nullptr;
-		if (src_design && this->design)
-			copy_src_into(other, src_design, cell, this->design);
-	}
+	if (src_design && this->design)
+		copy_src_into(other, src_design, cell, this->design);
 	return cell;
 }
 
diff --git a/kernel/twine.h b/kernel/twine.h
index 8f9372061..8fb4cf2c4 100644
--- a/kernel/twine.h
+++ b/kernel/twine.h
@@ -120,12 +120,19 @@ struct Twine {
 		auto operator<=>(const Suffix&) const = default;
 	};
 
-	std::variant<std::monostate, std::string, std::vector<TwineRef>, Suffix> data;
+	struct AutoPrefix {
+		const std::string *prefix;
+		std::string tail;
+		auto operator<=>(const AutoPrefix&) const = default;
+	};
+
+	std::variant<std::monostate, std::string, std::vector<TwineRef>, Suffix, AutoPrefix> data;
 
 	bool is_dead() const { return std::holds_alternative<std::monostate>(data); }
 	bool is_leaf() const { return std::holds_alternative<std::string>(data); }
 	bool is_concat() const { return std::holds_alternative<std::vector<TwineRef>>(data); }
 	bool is_suffix() const { return std::holds_alternative<Suffix>(data); }
+	bool is_auto_prefix() const { return std::holds_alternative<AutoPrefix>(data); }
 	bool is_flat() const { return is_leaf() || is_suffix(); }
 	const std::string &leaf() const { return std::get<std::string>(data); }
 	const std::vector<TwineRef> &children() const { return std::get<std::vector<TwineRef>>(data); }
@@ -363,6 +370,10 @@ struct TwinePool {
 	// and tag publicity themselves (or use the add(std::string) overload).
 	// Suffix names inherit the prefix handle's publicity.
 	TwineRef add(Twine t) {
+		if (auto *ap = std::get_if<Twine::AutoPrefix>(&t.data)) {
+			TwineRef pref = add_inner(Twine{*ap->prefix});
+			return add_inner(Twine{Twine::Suffix{pref, std::move(ap->tail)}});
+		}
 		bool is_public = false;
 		if (auto *sfx = std::get_if<Twine::Suffix>(&t.data)) {
 			is_public = twine_is_public(sfx->prefix);
@@ -649,6 +660,10 @@ struct TwineChildPool {
 
 	// Local analog of TwinePool::add; see there for the convention.
 	TwineRef add(Twine t) {
+		if (auto *ap = std::get_if<Twine::AutoPrefix>(&t.data)) {
+			TwineRef pref = add_inner(Twine{*ap->prefix});
+			return add_inner(Twine{Twine::Suffix{pref, std::move(ap->tail)}});
+		}
 		bool is_public = false;
 		if (auto *leaf = std::get_if<std::string>(&t.data)) {
 			assert(!leaf->empty());
diff --git a/kernel/yosys_common.h b/kernel/yosys_common.h
index dc807a7da..ddfec742d 100644
--- a/kernel/yosys_common.h
+++ b/kernel/yosys_common.h
@@ -308,15 +308,15 @@ RTLIL::IdString new_id_suffix(std::string_view file, int line, std::string_view
 #define NEW_ID_SUFFIX(suffix) \
 	YOSYS_NAMESPACE_PREFIX new_id_suffix(__FILE__, __LINE__, __FUNCTION__, suffix)
 #define NEW_TWINE \
-	YOSYS_NAMESPACE_PREFIX Twine{*[](std::string_view func) -> const std::string * { \
+	YOSYS_NAMESPACE_PREFIX Twine{YOSYS_NAMESPACE_PREFIX Twine::AutoPrefix{[](std::string_view func) -> const std::string * { \
 		static std::unique_ptr<const std::string> prefix(YOSYS_NAMESPACE_PREFIX create_id_prefix(__FILE__, __LINE__, func)); \
 		return prefix.get(); \
-	}(__FUNCTION__) + std::to_string(YOSYS_NAMESPACE_PREFIX autoidx++)}
+	}(__FUNCTION__), std::to_string(YOSYS_NAMESPACE_PREFIX autoidx++)}}
 #define NEW_TWINE_SUFFIX(suffix) \
-	YOSYS_NAMESPACE_PREFIX Twine{*[](std::string_view func) -> const std::string * { \
+	YOSYS_NAMESPACE_PREFIX Twine{YOSYS_NAMESPACE_PREFIX Twine::AutoPrefix{[](std::string_view func) -> const std::string * { \
 		static std::unique_ptr<const std::string> prefix(YOSYS_NAMESPACE_PREFIX create_id_prefix(__FILE__, __LINE__, func)); \
 		return prefix.get(); \
-	}(__FUNCTION__) + std::string(suffix) + "$" + std::to_string(YOSYS_NAMESPACE_PREFIX autoidx++)}
+	}(__FUNCTION__), std::string(suffix) + "$" + std::to_string(YOSYS_NAMESPACE_PREFIX autoidx++)}}
 
 namespace ID = RTLIL::ID;