Merge 054de3c236 into 5d0847f6fb

Catch partial support of SVI

Makefile

@@ -95,14 +95,14 @@ TARGETS = $(PROGRAM_PREFIX)yosys$(EXE) $(PROGRAM_PREFIX)yosys-config
 PRETTY = 1
 SMALL = 0
 
-# Unit test
-UNITESTPATH := tests/unit
-
 all: top-all
 
 YOSYS_SRC := $(dir $(firstword $(MAKEFILE_LIST)))
 VPATH := $(YOSYS_SRC)
 
+# Unit test
+UNITESTPATH := $(YOSYS_SRC)/tests/unit
+
 export CXXSTD ?= c++17
 CXXFLAGS := $(CXXFLAGS) -Wall -Wextra -ggdb -I. -I"$(YOSYS_SRC)" -MD -MP -D_YOSYS_ -fPIC -I$(PREFIX)/include
 LIBS := $(LIBS) -lstdc++ -lm
@@ -161,7 +161,7 @@ ifeq ($(OS), Haiku)
 CXXFLAGS += -D_DEFAULT_SOURCE
 endif
 
-YOSYS_VER := 0.58+138
+YOSYS_VER := 0.58+162
 YOSYS_MAJOR := $(shell echo $(YOSYS_VER) | cut -d'.' -f1)
 YOSYS_MINOR := $(shell echo $(YOSYS_VER) | cut -d'.' -f2 | cut -d'+' -f1)
 YOSYS_COMMIT := $(shell echo $(YOSYS_VER) | cut -d'+' -f2)
@@ -1135,7 +1135,7 @@ DOC_TARGET ?= html
 docs: docs/prep
 	$(Q) $(MAKE) -C docs $(DOC_TARGET)
 
-clean: clean-py
+clean: clean-py clean-unit-test
 	rm -rf share
 	rm -f $(OBJS) $(GENFILES) $(TARGETS) $(EXTRA_TARGETS) $(EXTRA_OBJS)
 	rm -f kernel/version_*.o kernel/version_*.cc
@@ -1150,7 +1150,7 @@ clean: clean-py
 	rm -f tests/svinterfaces/*.log_stdout tests/svinterfaces/*.log_stderr tests/svinterfaces/dut_result.txt tests/svinterfaces/reference_result.txt tests/svinterfaces/a.out tests/svinterfaces/*_syn.v tests/svinterfaces/*.diff
 	rm -f  tests/tools/cmp_tbdata
 	rm -f $(addsuffix /run-test.mk,$(MK_TEST_DIRS))
-	-$(MAKE) -C docs clean
+	-$(MAKE) -C $(YOSYS_SRC)/docs clean
 	rm -rf docs/util/__pycache__
 	rm -f libyosys.so
 
@@ -1162,7 +1162,7 @@ clean-py:
 	rm -rf kernel/*.pyh
 
 clean-abc:
-	$(MAKE) -C abc DEP= clean
+	$(MAKE) -C $(YOSYS_SRC)/abc DEP= clean
 	rm -f $(PROGRAM_PREFIX)yosys-abc$(EXE) $(PROGRAM_PREFIX)yosys-libabc.a abc/abc-[0-9a-f]* abc/libabc-[0-9a-f]*.a .git-abc-submodule-hash
 
 mrproper: clean

abc

@@ -1 +1 @@
-Subproject commit fa186342baefea06e7c2aa13fe51f338ffc84912
+Subproject commit 1c5ed1ce378cc04beac30bb31abc4c37c8467042

backends/verilog/verilog_backend.cc

@@ -108,22 +108,30 @@ IdString initial_id;
 
 void reset_auto_counter_id(RTLIL::IdString id, bool may_rename)
 {
-	const char *str = id.c_str();
-
-	if (*str == '$' && may_rename && !norename)
-		auto_name_map[id] = auto_name_counter++;
-
-	if (str[0] != '\\' || str[1] != '_' || str[2] == 0)
+	auto it = id.begin();
+	auto it_end = id.end();
+	if (it == it_end)
 		return;
 
-	for (int i = 2; str[i] != 0; i++) {
-		if (str[i] == '_' && str[i+1] == 0)
+	if (*it == '$' && may_rename && !norename)
+		auto_name_map[id] = auto_name_counter++;
+
+	if (*it != '\\' || *it != '_' || (it + 1) == it_end)
+		return;
+
+	it += 2;
+	auto start = it;
+	while (it != it_end) {
+		char ch = *it;
+		if (ch == '_' && (it + 1) == it_end)
 			continue;
-		if (str[i] < '0' || str[i] > '9')
+		if (ch < '0' || ch > '9')
 			return;
 	}
 
-	int num = atoi(str+2);
+	std::string s;
+	std::copy(start, it_end, std::back_inserter(s));
+	int num = atoi(s.c_str());
 	if (num >= auto_name_offset)
 		auto_name_offset = num + 1;
 }

docs/source/using_yosys/verilog.rst

@@ -9,7 +9,7 @@ Yosys and there are currently no plans to add support
 for them:
 
 - Non-synthesizable language features as defined in
-	IEC 62142(E):2005 / IEEE Std. 1364.1(E):2002
+  IEC 62142(E):2005 / IEEE Std. 1364.1(E):2002
 
 - The ``tri``, ``triand`` and ``trior`` net types
 
@@ -356,21 +356,29 @@ from SystemVerilog:
   files being read into the same design afterwards.
 
 - typedefs are supported (including inside packages)
-	- type casts are currently not supported
+
+  - type casts are currently not supported
 
 - enums are supported (including inside packages)
-	- but are currently not strongly typed
+
+  - but are currently not strongly typed
 
 - packed structs and unions are supported
-	- arrays of packed structs/unions are currently not supported
-	- structure literals are currently not supported
+
+  - arrays of packed structs/unions are currently not supported
+  - structure literals are currently not supported
 
 - multidimensional arrays are supported
-	- array assignment of unpacked arrays is currently not supported
-	- array literals are currently not supported
 
-- SystemVerilog interfaces (SVIs) are supported. Modports for specifying whether
-  ports are inputs or outputs are supported.
+  - array assignment of unpacked arrays is currently not supported
+  - array literals are currently not supported
+
+- SystemVerilog interfaces (SVIs), including modports for specifying whether
+  ports are inputs or outputs, are partially supported.
+
+  - interfaces must be provided as *named* arguments, not positional arguments.
+    i.e. ``foo bar(.intf(intf0), .x(x));`` is supported but ``foo bar(intf0,
+    x);`` is not.
 
 - Assignments within expressions are supported.
 

kernel/driver.cc

@@ -709,6 +709,8 @@ int main(int argc, char **argv)
 				total_ns += it.second->runtime_ns + 1;
 				timedat.insert(make_tuple(it.second->runtime_ns + 1, it.second->call_counter, it.first));
 			}
+		timedat.insert(make_tuple(RTLIL::OwningIdString::garbage_collection_ns() + 1,
+				RTLIL::OwningIdString::garbage_collection_count(), "id_gc"));
 
 		if (timing_details)
 		{

kernel/io.cc

@@ -606,7 +606,7 @@ void format_emit_idstring(std::string &result, std::string_view spec, int *dynam
 {
 	if (spec == "%s") {
 		// Format checking will have guaranteed num_dynamic_ints == 0.
-		result += arg.c_str();
+		arg.append_to(&result);
 		return;
 	}
 	format_emit_stringf(result, spec, dynamic_ints, num_dynamic_ints, arg.c_str());

kernel/register.cc

@@ -42,6 +42,23 @@ std::map<std::string, Backend*> backend_register;
 
 std::vector<std::string> Frontend::next_args;
 
+bool GarbageCollectionGuard::is_enabled_ = true;
+
+static bool garbage_collection_requested = false;
+
+void request_garbage_collection()
+{
+	garbage_collection_requested = true;
+}
+
+void try_collect_garbage()
+{
+	if (!GarbageCollectionGuard::is_enabled() || !garbage_collection_requested)
+		return;
+	garbage_collection_requested = false;
+	RTLIL::OwningIdString::collect_garbage();
+}
+
 Pass::Pass(std::string name, std::string short_help, source_location location) : 
 	pass_name(name), short_help(short_help), location(location)
 {
@@ -112,6 +129,11 @@ void Pass::post_execute(Pass::pre_post_exec_state_t state)
 	int64_t time_ns = PerformanceTimer::query() - state.begin_ns;
 	runtime_ns += time_ns;
 	current_pass = state.parent_pass;
+	subtract_from_current_runtime_ns(time_ns);
+}
+
+void Pass::subtract_from_current_runtime_ns(int64_t time_ns)
+{
 	if (current_pass)
 		current_pass->runtime_ns -= time_ns;
 }
@@ -263,14 +285,19 @@ void Pass::call(RTLIL::Design *design, std::vector<std::string> args)
 
 	if (pass_register.count(args[0]) == 0)
 		log_cmd_error("No such command: %s (type 'help' for a command overview)\n", args[0]);
+	Pass *pass = pass_register[args[0]];
 
-	if (pass_register[args[0]]->experimental_flag)
+	// Collect garbage before the next pass if requested. No need to collect garbage after the last pass.
+	try_collect_garbage();
+	GarbageCollectionGuard gc_guard(pass->allow_garbage_collection_during_pass());
+
+	if (pass->experimental_flag)
 		log_experimental(args[0]);
 
 	size_t orig_sel_stack_pos = design->selection_stack.size();
-	auto state = pass_register[args[0]]->pre_execute();
-	pass_register[args[0]]->execute(args, design);
-	pass_register[args[0]]->post_execute(state);
+	auto state = pass->pre_execute();
+	pass->execute(args, design);
+	pass->post_execute(state);
 	while (design->selection_stack.size() > orig_sel_stack_pos)
 		design->pop_selection();
 }

kernel/register.h

@@ -50,6 +50,30 @@ struct source_location { // dummy placeholder
 
 YOSYS_NAMESPACE_BEGIN
 
+// Track whether garbage collection is enabled. Garbage collection must be disabled
+// while any RTLIL objects (e.g. non-owning non-immortal IdStrings) exist outside Designs.
+// Garbage collection is disabled whenever any GarbageCollectionGuard(false) is on the
+// stack. These objects must be stack-allocated on the main thread.
+class GarbageCollectionGuard
+{
+	bool was_enabled;
+	static bool is_enabled_;
+public:
+	GarbageCollectionGuard(bool allow) : was_enabled(is_enabled_) {
+		is_enabled_ &= allow;
+	}
+	~GarbageCollectionGuard() {
+		is_enabled_ = was_enabled;
+	}
+	static bool is_enabled() { return is_enabled_; }
+};
+
+// Call from anywhere to request GC at the next safe point.
+void request_garbage_collection();
+
+// GC if GarbageCollectionGuard::is_enabled() and GC was requested.
+void try_collect_garbage();
+
 struct Pass
 {
 	std::string pass_name, short_help;
@@ -71,6 +95,8 @@ struct Pass
 	bool experimental_flag = false;
 	bool internal_flag = false;
 
+	static void subtract_from_current_runtime_ns(int64_t time_ns);
+
 	void experimental() {
 		experimental_flag = true;
 	}
@@ -108,6 +134,10 @@ struct Pass
 	virtual void on_register();
 	virtual void on_shutdown();
 	virtual bool replace_existing_pass() const { return false; }
+
+	// This should return false if the pass holds onto RTLIL objects outside a Design while it
+	// calls nested passes. For safety, we default to assuming the worst.
+	virtual bool allow_garbage_collection_during_pass() const { return false; }
 };
 
 struct ScriptPass : Pass
@@ -126,6 +156,8 @@ struct ScriptPass : Pass
 	void run_nocheck(std::string command, std::string info = std::string());
 	void run_script(RTLIL::Design *design, std::string run_from = std::string(), std::string run_to = std::string());
 	void help_script();
+
+	bool allow_garbage_collection_during_pass() const override { return true; }
 };
 
 struct Frontend : Pass

kernel/rtlil.cc

@@ -28,6 +28,7 @@
 
 #include <string.h>
 #include <algorithm>
+#include <charconv>
 #include <optional>
 #include <string_view>
 
@@ -35,20 +36,14 @@ YOSYS_NAMESPACE_BEGIN
 
 bool RTLIL::IdString::destruct_guard_ok = false;
 RTLIL::IdString::destruct_guard_t RTLIL::IdString::destruct_guard;
-std::vector<char*> RTLIL::IdString::global_id_storage_;
+std::vector<RTLIL::IdString::Storage> RTLIL::IdString::global_id_storage_;
 std::unordered_map<std::string_view, int> RTLIL::IdString::global_id_index_;
+std::unordered_map<int, const std::string*> RTLIL::IdString::global_autoidx_id_prefix_storage_;
+std::unordered_map<int, char*> RTLIL::IdString::global_autoidx_id_storage_;
 #ifndef YOSYS_NO_IDS_REFCNT
-std::vector<uint32_t> RTLIL::IdString::global_refcount_storage_;
+std::unordered_map<int, int> RTLIL::IdString::global_refcount_storage_;
 std::vector<int> RTLIL::IdString::global_free_idx_list_;
 #endif
-#ifdef YOSYS_USE_STICKY_IDS
-int RTLIL::IdString::last_created_idx_[8];
-int RTLIL::IdString::last_created_idx_ptr_;
-#endif
-
-#define X(_id) const RTLIL::IdString RTLIL::IDInternal::_id(RTLIL::StaticId::_id);
-#include "kernel/constids.inc"
-#undef X
 
 static void populate(std::string_view name)
 {
@@ -57,21 +52,89 @@ static void populate(std::string_view name)
 		name = name.substr(1);
 	}
 	RTLIL::IdString::global_id_index_.insert({name, GetSize(RTLIL::IdString::global_id_storage_)});
-	RTLIL::IdString::global_id_storage_.push_back(const_cast<char*>(name.data()));
+	RTLIL::IdString::global_id_storage_.push_back({const_cast<char*>(name.data()), GetSize(name)});
 }
 
 void RTLIL::IdString::prepopulate()
 {
 	int size = static_cast<short>(RTLIL::StaticId::STATIC_ID_END);
 	global_id_storage_.reserve(size);
-	RTLIL::IdString::global_id_storage_.push_back(const_cast<char*>(""));
 	global_id_index_.reserve(size);
-	global_refcount_storage_.resize(size, 1);
+	RTLIL::IdString::global_id_index_.insert({"", 0});
+	RTLIL::IdString::global_id_storage_.push_back({const_cast<char*>(""), 0});
 #define X(N) populate("\\" #N);
 #include "kernel/constids.inc"
 #undef X
 }
 
+static std::optional<int> parse_autoidx(std::string_view v)
+{
+	// autoidx values can never be <= 0, so there can never be a leading 0 digit.
+	if (v.empty() || v[0] == '0')
+		return std::nullopt;
+	for (char ch : v) {
+		if (ch < '0' || ch > '9')
+			return std::nullopt;
+	}
+	int p_autoidx;
+	if (std::from_chars(v.data(), v.data() + v.size(), p_autoidx).ec != std::errc())
+		return std::nullopt;
+	return p_autoidx;
+}
+
+int RTLIL::IdString::really_insert(std::string_view p, std::unordered_map<std::string_view, int>::iterator &it)
+{
+	ensure_prepopulated();
+
+	log_assert(p[0] == '$' || p[0] == '\\');
+	for (char ch : p)
+		if ((unsigned)ch <= (unsigned)' ')
+			log_error("Found control character or space (0x%02x) in string '%s' which is not allowed in RTLIL identifiers\n", ch, std::string(p).c_str());
+
+	if (p.substr(0, 6) == "$auto$") {
+		size_t autoidx_pos = p.find_last_of('$') + 1;
+		std::optional<int> p_autoidx = parse_autoidx(p.substr(autoidx_pos));
+		if (p_autoidx.has_value()) {
+			auto prefix_it = global_autoidx_id_prefix_storage_.find(-*p_autoidx);
+			if (prefix_it != global_autoidx_id_prefix_storage_.end() && p.substr(0, autoidx_pos) == *prefix_it->second)
+				return -*p_autoidx;
+			// Ensure NEW_ID/NEW_ID_SUFFIX will not create collisions with the ID
+			// we're about to create.
+			autoidx = std::max(autoidx, *p_autoidx + 1);
+		}
+	}
+
+#ifndef YOSYS_NO_IDS_REFCNT
+	if (global_free_idx_list_.empty()) {
+		log_assert(global_id_storage_.size() < 0x40000000);
+		global_free_idx_list_.push_back(global_id_storage_.size());
+		global_id_storage_.push_back({nullptr, 0});
+	}
+
+	int idx = global_free_idx_list_.back();
+	global_free_idx_list_.pop_back();
+#else
+	int idx = global_id_storage_.size();
+	global_id_index_[global_id_storage_.back()] = idx;
+#endif
+	char* buf = static_cast<char*>(malloc(p.size() + 1));
+	memcpy(buf, p.data(), p.size());
+	buf[p.size()] = 0;
+	global_id_storage_.at(idx) = {buf, GetSize(p)};
+	global_id_index_.insert(it, {std::string_view(buf, p.size()), idx});
+
+	if (yosys_xtrace) {
+		log("#X# New IdString '%s' with index %d.\n", global_id_storage_.at(idx).buf, idx);
+		log_backtrace("-X- ", yosys_xtrace-1);
+	}
+
+#ifdef YOSYS_XTRACE_GET_PUT
+	if (yosys_xtrace)
+		log("#X# GET-BY-NAME '%s' (index %d, refcount %u)\n", global_id_storage_.at(idx), idx, refcount(idx));
+#endif
+	return idx;
+}
+
 static constexpr bool check_well_known_id_order()
 {
 	int size = sizeof(IdTable) / sizeof(IdTable[0]);
@@ -85,6 +148,156 @@ static constexpr bool check_well_known_id_order()
 // and in sorted ascii order, as required by the ID macro.
 static_assert(check_well_known_id_order());
 
+struct IdStringCollector {
+	void trace(IdString id) {
+		live.insert(id.index_);
+	}
+	template <typename T> void trace(const T* v) {
+		trace(*v);
+	}
+	template <typename V> void trace(const std::vector<V> &v) {
+		for (const auto &element : v)
+			trace(element);
+	}
+	template <typename K> void trace(const pool<K> &p) {
+		for (const auto &element : p)
+			trace(element);
+	}
+	template <typename K, typename V> void trace(const dict<K, V> &d) {
+		for (const auto &[key, value] : d) {
+			trace(key);
+			trace(value);
+		}
+	}
+	template <typename K, typename V> void trace_keys(const dict<K, V> &d) {
+		for (const auto &[key, value] : d) {
+			trace(key);
+		}
+	}
+	template <typename K, typename V> void trace_values(const dict<K, V> &d) {
+		for (const auto &[key, value] : d) {
+			trace(value);
+		}
+	}
+	template <typename K> void trace(const idict<K> &d) {
+		for (const auto &element : d)
+			trace(element);
+	}
+
+	void trace(const RTLIL::Design &design) {
+		trace_values(design.modules_);
+		trace(design.selection_vars);
+	}
+	void trace(const RTLIL::Selection &selection_var) {
+		trace(selection_var.selected_modules);
+		trace(selection_var.selected_members);
+	}
+	void trace_named(const RTLIL::NamedObject named) {
+		trace_keys(named.attributes);
+		trace(named.name);
+	}
+	void trace(const RTLIL::Module &module) {
+		trace_named(module);
+		trace_values(module.wires_);
+		trace_values(module.cells_);
+		trace(module.avail_parameters);
+		trace_keys(module.parameter_default_values);
+		trace_values(module.memories);
+		trace_values(module.processes);
+	}
+	void trace(const RTLIL::Wire &wire) {
+		trace_named(wire);
+		if (wire.known_driver())
+			trace(wire.driverPort());
+	}
+	void trace(const RTLIL::Cell &cell) {
+		trace_named(cell);
+		trace(cell.type);
+		trace_keys(cell.connections_);
+		trace_keys(cell.parameters);
+	}
+	void trace(const RTLIL::Memory &mem) {
+		trace_named(mem);
+	}
+	void trace(const RTLIL::Process &proc) {
+		trace_named(proc);
+		trace(proc.root_case);
+		trace(proc.syncs);
+	}
+	void trace(const RTLIL::CaseRule &rule) {
+		trace_keys(rule.attributes);
+		trace(rule.switches);
+	}
+	void trace(const RTLIL::SwitchRule &rule) {
+		trace_keys(rule.attributes);
+		trace(rule.cases);
+	}
+	void trace(const RTLIL::SyncRule &rule) {
+		trace(rule.mem_write_actions);
+	}
+	void trace(const RTLIL::MemWriteAction &action) {
+		trace_keys(action.attributes);
+		trace(action.memid);
+	}
+
+	std::unordered_set<int> live;
+};
+
+int64_t RTLIL::OwningIdString::gc_ns;
+int RTLIL::OwningIdString::gc_count;
+
+void RTLIL::OwningIdString::collect_garbage()
+{
+	int64_t start = PerformanceTimer::query();
+#ifndef YOSYS_NO_IDS_REFCNT
+	IdStringCollector collector;
+	for (auto &[idx, design] : *RTLIL::Design::get_all_designs()) {
+		collector.trace(*design);
+	}
+	int size = GetSize(global_id_storage_);
+	for (int i = static_cast<int>(StaticId::STATIC_ID_END); i < size; ++i) {
+		RTLIL::IdString::Storage &storage = global_id_storage_.at(i);
+		if (storage.buf == nullptr)
+			continue;
+		if (collector.live.find(i) != collector.live.end())
+			continue;
+		if (global_refcount_storage_.find(i) != global_refcount_storage_.end())
+			continue;
+
+		if (yosys_xtrace) {
+			log("#X# Removed IdString '%s' with index %d.\n", storage.buf, i);
+			log_backtrace("-X- ", yosys_xtrace-1);
+		}
+
+		global_id_index_.erase(std::string_view(storage.buf, storage.size));
+		free(storage.buf);
+		storage = {nullptr, 0};
+		global_free_idx_list_.push_back(i);
+	}
+
+	for (auto it = global_autoidx_id_prefix_storage_.begin(); it != global_autoidx_id_prefix_storage_.end();) {
+		if (collector.live.find(it->first) != collector.live.end()) {
+			++it;
+			continue;
+		}
+		if (global_refcount_storage_.find(it->first) != global_refcount_storage_.end()) {
+			++it;
+			continue;
+		}
+		auto str_it = global_autoidx_id_storage_.find(it->first);
+		if (str_it != global_autoidx_id_storage_.end()) {
+			delete[] str_it->second;
+			global_autoidx_id_storage_.erase(str_it);
+		}
+		it = global_autoidx_id_prefix_storage_.erase(it);
+	}
+#endif
+	int64_t time_ns = PerformanceTimer::query() - start;
+	Pass::subtract_from_current_runtime_ns(time_ns);
+	gc_ns += time_ns;
+	++gc_count;
+}
+
 dict<std::string, std::string> RTLIL::constpad;
 
 static const pool<IdString> &builtin_ff_cell_types_internal() {
@@ -1083,9 +1296,7 @@ RTLIL::Design::Design()
 	refcount_modules_ = 0;
 	push_full_selection();
 
-#ifdef YOSYS_ENABLE_PYTHON
 	RTLIL::Design::get_all_designs()->insert(std::pair<unsigned int, RTLIL::Design*>(hashidx_, this));
-#endif
 }
 
 RTLIL::Design::~Design()
@@ -1094,18 +1305,14 @@ RTLIL::Design::~Design()
 		delete pr.second;
 	for (auto n : bindings_)
 		delete n;
-#ifdef YOSYS_ENABLE_PYTHON
 	RTLIL::Design::get_all_designs()->erase(hashidx_);
-#endif
 }
 
-#ifdef YOSYS_ENABLE_PYTHON
 static std::map<unsigned int, RTLIL::Design*> all_designs;
 std::map<unsigned int, RTLIL::Design*> *RTLIL::Design::get_all_designs(void)
 {
 	return &all_designs;
 }
-#endif
 
 RTLIL::ObjRange<RTLIL::Module*> RTLIL::Design::modules()
 {

kernel/rtlil.h

@@ -120,26 +120,22 @@ namespace RTLIL
 	struct Process;
 	struct Binding;
 	struct IdString;
-	struct StaticIdString;
+	struct OwningIdString;
 
 	typedef std::pair<SigSpec, SigSpec> SigSig;
-
-	struct StaticIdString {
-		constexpr StaticIdString(StaticId id, const IdString &id_str) : id_str(id_str), id(id) {}
-		constexpr inline operator const IdString &() const { return id_str; }
-		constexpr inline int index() const { return static_cast<short>(id); }
-		constexpr inline const IdString &id_string() const { return id_str; }
-
-		const IdString &id_str;
-		const StaticId id;
-	};
 };
 
 struct RTLIL::IdString
 {
+	struct Storage {
+		char *buf;
+		int size;
+
+		std::string_view str_view() const { return {buf, static_cast<size_t>(size)}; }
+	};
+
 	#undef YOSYS_XTRACE_GET_PUT
 	#undef YOSYS_SORT_ID_FREE_LIST
-	#undef YOSYS_USE_STICKY_IDS
 	#undef YOSYS_NO_IDS_REFCNT
 
 	// the global id string cache
@@ -150,200 +146,85 @@ struct RTLIL::IdString
 		~destruct_guard_t() { destruct_guard_ok = false; }
 	} destruct_guard;
 
-	static std::vector<char*> global_id_storage_;
+	// String storage for non-autoidx IDs
+	static std::vector<Storage> global_id_storage_;
+	// Lookup table for non-autoidx IDs
 	static std::unordered_map<std::string_view, int> global_id_index_;
+	// Shared prefix string storage for autoidx IDs, which have negative
+	// indices. Append the negated (i.e. positive) ID to this string to get
+	// the real string. The prefix strings must live forever.
+	static std::unordered_map<int, const std::string*> global_autoidx_id_prefix_storage_;
+	// Explicit string storage for autoidx IDs
+	static std::unordered_map<int, char*> global_autoidx_id_storage_;
 #ifndef YOSYS_NO_IDS_REFCNT
-	// For prepopulated IdStrings, the refcount is meaningless since they
-	// are never freed even if the refcount is zero. For code efficiency
-	// we increment the refcount of prepopulated IdStrings like any other string,
-	// but we never decrement the refcount or check whether it's zero.
-	// So, make this unsigned because refcounts of preopulated IdStrings may overflow
-	// and overflow of signed integers is undefined behavior.
-	static std::vector<uint32_t> global_refcount_storage_;
+	// All (index, refcount) pairs in this map have refcount > 0.
+	static std::unordered_map<int, int> global_refcount_storage_;
 	static std::vector<int> global_free_idx_list_;
 #endif
 
-#ifdef YOSYS_USE_STICKY_IDS
-	static int last_created_idx_ptr_;
-	static int last_created_idx_[8];
-#endif
+	static int refcount(int idx) {
+		auto it = global_refcount_storage_.find(idx);
+		if (it == global_refcount_storage_.end())
+			return 0;
+		return it->second;
+	}
 
 	static inline void xtrace_db_dump()
 	{
 	#ifdef YOSYS_XTRACE_GET_PUT
 		for (int idx = 0; idx < GetSize(global_id_storage_); idx++)
 		{
-			if (global_id_storage_.at(idx) == nullptr)
+			if (global_id_storage_.at(idx).buf == nullptr)
 				log("#X# DB-DUMP index %d: FREE\n", idx);
 			else
-				log("#X# DB-DUMP index %d: '%s' (ref %u)\n", idx, global_id_storage_.at(idx), global_refcount_storage_.at(idx));
+				log("#X# DB-DUMP index %d: '%s' (ref %u)\n", idx, refcount(idx).buf, refcount);
 		}
 	#endif
 	}
 
 	static inline void checkpoint()
 	{
-	#ifdef YOSYS_USE_STICKY_IDS
-		last_created_idx_ptr_ = 0;
-		for (int i = 0; i < 8; i++) {
-			if (last_created_idx_[i])
-				put_reference(last_created_idx_[i]);
-			last_created_idx_[i] = 0;
-		}
-	#endif
 	#ifdef YOSYS_SORT_ID_FREE_LIST
 		std::sort(global_free_idx_list_.begin(), global_free_idx_list_.end(), std::greater<int>());
 	#endif
 	}
 
-	static inline int get_reference(int idx)
-	{
-	#ifndef YOSYS_NO_IDS_REFCNT
-		global_refcount_storage_[idx]++;
-	#endif
-	#ifdef YOSYS_XTRACE_GET_PUT
-		if (yosys_xtrace && idx >= static_cast<short>(StaticId::STATIC_ID_END))
-			log("#X# GET-BY-INDEX '%s' (index %d, refcount %u)\n", global_id_storage_.at(idx), idx, global_refcount_storage_.at(idx));
-	#endif
-		return idx;
-	}
-
-	static int get_reference(const char *p)
-	{
-		return get_reference(std::string_view(p));
-	}
-
-	static int get_reference(std::string_view p)
+	static int insert(std::string_view p)
 	{
 		log_assert(destruct_guard_ok);
 
 		auto it = global_id_index_.find(p);
 		if (it != global_id_index_.end()) {
-	#ifndef YOSYS_NO_IDS_REFCNT
-			global_refcount_storage_.at(it->second)++;
-	#endif
 	#ifdef YOSYS_XTRACE_GET_PUT
 			if (yosys_xtrace)
-				log("#X# GET-BY-NAME '%s' (index %d, refcount %u)\n", global_id_storage_.at(it->second), it->second, global_refcount_storage_.at(it->second));
+				log("#X# GET-BY-NAME '%s' (index %d, refcount %u)\n", global_id_storage_.at(it->second).buf, it->second, refcount(it->second));
 	#endif
 			return it->second;
 		}
-
-		ensure_prepopulated();
-
-		if (p.empty())
-			return 0;
-
-		log_assert(p[0] == '$' || p[0] == '\\');
-		for (char ch : p)
-			if ((unsigned)ch <= (unsigned)' ')
-				log_error("Found control character or space (0x%02x) in string '%s' which is not allowed in RTLIL identifiers\n", ch, std::string(p).c_str());
-
-	#ifndef YOSYS_NO_IDS_REFCNT
-		if (global_free_idx_list_.empty()) {
-			log_assert(global_id_storage_.size() < 0x40000000);
-			global_free_idx_list_.push_back(global_id_storage_.size());
-			global_id_storage_.push_back(nullptr);
-			global_refcount_storage_.push_back(0);
-		}
-
-		int idx = global_free_idx_list_.back();
-		global_free_idx_list_.pop_back();
-		char* buf = static_cast<char*>(malloc(p.size() + 1));
-		memcpy(buf, p.data(), p.size());
-		buf[p.size()] = 0;
-		global_id_storage_.at(idx) = buf;
-		global_id_index_.insert(it, {std::string_view(buf, p.size()), idx});
-		global_refcount_storage_.at(idx)++;
-	#else
-		int idx = global_id_storage_.size();
-		global_id_storage_.push_back(strdup(p));
-		global_id_index_[global_id_storage_.back()] = idx;
-	#endif
-
-		if (yosys_xtrace) {
-			log("#X# New IdString '%s' with index %d.\n", global_id_storage_.at(idx), idx);
-			log_backtrace("-X- ", yosys_xtrace-1);
-		}
-
-	#ifdef YOSYS_XTRACE_GET_PUT
-		if (yosys_xtrace)
-			log("#X# GET-BY-NAME '%s' (index %d, refcount %u)\n", global_id_storage_.at(idx), idx, global_refcount_storage_.at(idx));
-	#endif
-
-	#ifdef YOSYS_USE_STICKY_IDS
-		// Avoid Create->Delete->Create pattern
-		if (last_created_idx_[last_created_idx_ptr_])
-			put_reference(last_created_idx_[last_created_idx_ptr_]);
-		last_created_idx_[last_created_idx_ptr_] = idx;
-		get_reference(last_created_idx_[last_created_idx_ptr_]);
-		last_created_idx_ptr_ = (last_created_idx_ptr_ + 1) & 7;
-	#endif
-
-		return idx;
+		return really_insert(p, it);
 	}
 
-#ifndef YOSYS_NO_IDS_REFCNT
-	static inline void put_reference(int idx)
-	{
-		// put_reference() may be called from destructors after the destructor of
-		// global_refcount_storage_ has been run. in this case we simply do nothing.
-		if (idx < static_cast<short>(StaticId::STATIC_ID_END) || !destruct_guard_ok)
-			return;
-
-	#ifdef YOSYS_XTRACE_GET_PUT
-		if (yosys_xtrace) {
-			log("#X# PUT '%s' (index %d, refcount %u)\n", global_id_storage_.at(idx), idx, global_refcount_storage_.at(idx));
-		}
-	#endif
-
-		uint32_t &refcount = global_refcount_storage_[idx];
-
-		if (--refcount > 0)
-			return;
-
-		free_reference(idx);
+	// Inserts an ID with string `prefix + autoidx', incrementing autoidx.
+	// `prefix` must start with '$auto$', end with '$', and live forever.
+	static IdString new_autoidx_with_prefix(const std::string *prefix) {
+		int index = -(autoidx++);
+		global_autoidx_id_prefix_storage_.insert({index, prefix});
+		return from_index(index);
 	}
-	static inline void free_reference(int idx)
-	{
-		if (yosys_xtrace) {
-			log("#X# Removed IdString '%s' with index %d.\n", global_id_storage_.at(idx), idx);
-			log_backtrace("-X- ", yosys_xtrace-1);
-		}
-		log_assert(idx >= static_cast<short>(StaticId::STATIC_ID_END));
-
-		global_id_index_.erase(global_id_storage_.at(idx));
-		free(global_id_storage_.at(idx));
-		global_id_storage_.at(idx) = nullptr;
-		global_free_idx_list_.push_back(idx);
-	}
-#else
-	static inline void put_reference(int) { }
-#endif
 
 	// the actual IdString object is just is a single int
 
 	int index_;
 
-	inline IdString() : index_(0) { }
-	inline IdString(const char *str) : index_(get_reference(str)) { }
-	inline IdString(const IdString &str) : index_(get_reference(str.index_)) { }
+	constexpr inline IdString() : index_(0) { }
+	inline IdString(const char *str) : index_(insert(std::string_view(str))) { }
+	constexpr inline IdString(const IdString &str) : index_(str.index_) { }
 	inline IdString(IdString &&str) : index_(str.index_) { str.index_ = 0; }
-	inline IdString(const std::string &str) : index_(get_reference(std::string_view(str))) { }
-	inline IdString(std::string_view str) : index_(get_reference(str)) { }
-	inline IdString(StaticId id) : index_(static_cast<short>(id)) {}
-	inline ~IdString() { put_reference(index_); }
+	inline IdString(const std::string &str) : index_(insert(std::string_view(str))) { }
+	inline IdString(std::string_view str) : index_(insert(str)) { }
+	constexpr inline IdString(StaticId id) : index_(static_cast<short>(id)) {}
 
-	inline void operator=(const IdString &rhs) {
-		put_reference(index_);
-		index_ = get_reference(rhs.index_);
-	}
-
-	inline void operator=(IdString &&rhs) {
-		put_reference(index_);
-		index_ = rhs.index_;
-		rhs.index_ = 0;
-	}
+	IdString &operator=(const IdString &rhs) = default;
 
 	inline void operator=(const char *rhs) {
 		IdString id(rhs);
@@ -358,11 +239,156 @@ struct RTLIL::IdString
 	constexpr inline const IdString &id_string() const { return *this; }
 
 	inline const char *c_str() const {
-		return global_id_storage_.at(index_);
+		if (index_ >= 0)
+			return global_id_storage_.at(index_).buf;
+		auto it = global_autoidx_id_storage_.find(index_);
+		if (it != global_autoidx_id_storage_.end())
+			return it->second;
+
+		const std::string &prefix = *global_autoidx_id_prefix_storage_.at(index_);
+		std::string suffix = std::to_string(-index_);
+		char *c = new char[prefix.size() + suffix.size() + 1];
+		memcpy(c, prefix.data(), prefix.size());
+		memcpy(c + prefix.size(), suffix.c_str(), suffix.size() + 1);
+		global_autoidx_id_storage_.insert(it, {index_, c});
+		return c;
 	}
 
 	inline std::string str() const {
-		return std::string(global_id_storage_.at(index_));
+		std::string result;
+		append_to(&result);
+		return result;
+	}
+
+	inline void append_to(std::string *out) const {
+		if (index_ >= 0) {
+			*out += global_id_storage_.at(index_).str_view();
+			return;
+		}
+		*out += *global_autoidx_id_prefix_storage_.at(index_);
+		*out += std::to_string(-index_);
+	}
+
+	class Substrings {
+		std::string_view first_;
+		int suffix_number;
+		char buf[10];
+	public:
+		Substrings(const Storage &storage) : first_(storage.str_view()), suffix_number(-1) {}
+		// suffix_number must be non-negative
+		Substrings(const std::string *prefix, int suffix_number)
+				: first_(*prefix), suffix_number(suffix_number) {}
+		std::string_view first() { return first_; }
+		std::optional<std::string_view> next() {
+			if (suffix_number < 0)
+				return std::nullopt;
+                       int i = sizeof(buf);
+			do {
+				--i;
+                               buf[i] = (suffix_number % 10) + '0';
+                               suffix_number /= 10;
+			} while (suffix_number > 0);
+			suffix_number = -1;
+			return std::string_view(buf + i, sizeof(buf) - i);
+		}
+	};
+
+	class const_iterator {
+		const std::string *prefix;
+		std::string suffix;
+		const char *c_str;
+		int c_str_len;
+		// When this is INT_MAX it's the generic "end" value.
+		int index;
+
+	public:
+		using iterator_category = std::forward_iterator_tag;
+		using value_type = char;
+		using difference_type = std::ptrdiff_t;
+		using pointer = const char*;
+		using reference = const char&;
+
+		const_iterator(const Storage &storage) : prefix(nullptr), c_str(storage.buf), c_str_len(storage.size), index(0) {}
+		const_iterator(const std::string *prefix, int number) :
+				prefix(prefix), suffix(std::to_string(number)), c_str(nullptr), c_str_len(0), index(0) {}
+		// Construct end-marker
+		const_iterator() : prefix(nullptr), c_str(nullptr), c_str_len(0), index(INT_MAX) {}
+
+		int size() const {
+			if (c_str != nullptr)
+				return c_str_len;
+			return GetSize(*prefix) + GetSize(suffix);
+		}
+
+		char operator*() const {
+			if (c_str != nullptr)
+				return c_str[index];
+			int prefix_size = GetSize(*prefix);
+			if (index < prefix_size)
+				return prefix->at(index);
+			return suffix[index - prefix_size];
+		}
+
+		const_iterator& operator++() { ++index; return *this; }
+		const_iterator operator++(int) { const_iterator result(*this); ++index; return result; }
+		const_iterator& operator+=(int i) { index += i; return *this; }
+
+		const_iterator operator+(int add) {
+			const_iterator result = *this;
+			result += add;
+			return result;
+		}
+
+		bool operator==(const const_iterator& other) const {
+			return index == other.index || (other.index == INT_MAX && index == size())
+				|| (index == INT_MAX && other.index == other.size());
+		}
+		bool operator!=(const const_iterator& other) const {
+			return !(*this == other);
+		}
+	};
+	const_iterator begin() const {
+		if (index_ >= 0) {
+			return const_iterator(global_id_storage_.at(index_));
+		}
+		return const_iterator(global_autoidx_id_prefix_storage_.at(index_), -index_);
+	}
+	const_iterator end() const {
+		return const_iterator();
+	}
+
+	Substrings substrings() const {
+		if (index_ >= 0) {
+			return Substrings(global_id_storage_.at(index_));
+		}
+		return Substrings(global_autoidx_id_prefix_storage_.at(index_), -index_);
+	}
+
+	inline bool lt_by_name(const IdString &rhs) const {
+		Substrings lhs_it = substrings();
+		Substrings rhs_it = rhs.substrings();
+		std::string_view lhs_substr = lhs_it.first();
+		std::string_view rhs_substr = rhs_it.first();
+		while (true) {
+			int min = std::min(GetSize(lhs_substr), GetSize(rhs_substr));
+			int diff = memcmp(lhs_substr.data(), rhs_substr.data(), min);
+			if (diff != 0)
+				return diff < 0;
+			lhs_substr = lhs_substr.substr(min);
+			rhs_substr = rhs_substr.substr(min);
+			if (rhs_substr.empty()) {
+				if (std::optional<std::string_view> s = rhs_it.next())
+					rhs_substr = *s;
+				else
+					return false;
+			}
+			if (lhs_substr.empty()) {
+				if (std::optional<std::string_view> s = lhs_it.next())
+					lhs_substr = *s;
+				else
+					return true;
+			}
+		}
 	}
 
 	inline bool operator<(const IdString &rhs) const {
@@ -371,8 +397,6 @@ struct RTLIL::IdString
 
 	inline bool operator==(const IdString &rhs) const { return index_ == rhs.index_; }
 	inline bool operator!=(const IdString &rhs) const { return index_ != rhs.index_; }
-	inline bool operator==(const StaticIdString &rhs) const;
-	inline bool operator!=(const StaticIdString &rhs) const;
 
 	// The methods below are just convenience functions for better compatibility with std::string.
 
@@ -383,45 +407,84 @@ struct RTLIL::IdString
 	bool operator!=(const char *rhs) const { return strcmp(c_str(), rhs) != 0; }
 
 	char operator[](size_t i) const {
-					const char *p = c_str();
+		if (index_ >= 0) {
+			const Storage &storage = global_id_storage_.at(index_);
 #ifndef NDEBUG
-		for (; i != 0; i--, p++)
-			log_assert(*p != 0);
-		return *p;
-#else
-		return *(p + i);
+			log_assert(static_cast<int>(i) < storage.size);
 #endif
+			return *(storage.buf + i);
+		}
+		const std::string &id_start = *global_autoidx_id_prefix_storage_.at(index_);
+		if (i < id_start.size())
+			return id_start[i];
+		i -= id_start.size();
+		std::string suffix = std::to_string(-index_);
+#ifndef NDEBUG
+		// Allow indexing to access the trailing null.
+		log_assert(i <= suffix.size());
+#endif
+		return suffix[i];
 	}
 
 	std::string substr(size_t pos = 0, size_t len = std::string::npos) const {
-		if (len == std::string::npos || len >= strlen(c_str() + pos))
-			return std::string(c_str() + pos);
-		else
-			return std::string(c_str() + pos, len);
+		std::string result;
+		const_iterator it = begin() + pos;
+		const_iterator end_it = end();
+		if (len != std::string::npos && len < it.size() - pos) {
+			end_it = it + len;
+		}
+		std::copy(it, end_it, std::back_inserter(result));
+		return result;
 	}
 
 	int compare(size_t pos, size_t len, const char* s) const {
-		return strncmp(c_str()+pos, s, len);
+		const_iterator it = begin() + pos;
+		const_iterator end_it = end();
+		while (len > 0 && *s != 0 && it != end_it) {
+			int diff = *it - *s;
+			if (diff != 0)
+				return diff;
+			++it;
+			++s;
+			--len;
+		}
+		return 0;
 	}
 
-	bool begins_with(const char* prefix) const {
-		size_t len = strlen(prefix);
-		if (size() < len) return false;
-		return compare(0, len, prefix) == 0;
+	bool begins_with(std::string_view prefix) const {
+		Substrings it = substrings();
+		std::string_view substr = it.first();
+		while (true) {
+			int min = std::min(GetSize(substr), GetSize(prefix));
+			if (memcmp(substr.data(), prefix.data(), min) != 0)
+				return false;
+			prefix = prefix.substr(min);
+			if (prefix.empty())
+				return true;
+			substr = substr.substr(min);
+			if (substr.empty()) {
+				if (std::optional<std::string_view> s = it.next())
+					substr = *s;
+				else
+					return false;
+			}
+		}
 	}
 
-	bool ends_with(const char* suffix) const {
-		size_t len = strlen(suffix);
-		if (size() < len) return false;
-		return compare(size()-len, len, suffix) == 0;
+	bool ends_with(std::string_view suffix) const {
+		size_t sz = size();
+		if (sz < suffix.size()) return false;
+		return compare(sz - suffix.size(), suffix.size(), suffix.data()) == 0;
 	}
 
-	bool contains(const char* str) const {
-		return strstr(c_str(), str);
+	bool contains(std::string_view s) const {
+		if (index_ >= 0)
+			return global_id_storage_.at(index_).str_view().find(s) != std::string::npos;
+		return str().find(s) != std::string::npos;
 	}
 
 	size_t size() const {
-		return strlen(c_str());
+		return begin().size();
 	}
 
 	bool empty() const {
@@ -458,7 +521,6 @@ struct RTLIL::IdString
 	}
 
 	bool in(const IdString &rhs) const { return *this == rhs; }
-	bool in(const StaticIdString &rhs) const { return *this == rhs; }
 	bool in(const char *rhs) const { return *this == rhs; }
 	bool in(const std::string &rhs) const { return *this == rhs; }
 	inline bool in(const pool<IdString> &rhs) const;
@@ -468,6 +530,14 @@ struct RTLIL::IdString
 
 private:
 	static void prepopulate();
+	static int really_insert(std::string_view p, std::unordered_map<std::string_view, int>::iterator &it);
+
+protected:
+	static IdString from_index(int index) {
+		IdString result;
+		result.index_ = index;
+		return result;
+	}
 
 public:
 	static void ensure_prepopulated() {
@@ -476,6 +546,95 @@ public:
 	}
 };
 
+struct RTLIL::OwningIdString : public RTLIL::IdString {
+	inline OwningIdString() { }
+	inline OwningIdString(const OwningIdString &str) : IdString(str) { get_reference(); }
+	inline OwningIdString(const char *str) : IdString(str) { get_reference(); }
+	inline OwningIdString(const IdString &str) : IdString(str) { get_reference(); }
+	inline OwningIdString(IdString &&str) : IdString(str) {	get_reference(); }
+	inline OwningIdString(const std::string &str) : IdString(str) { get_reference(); }
+	inline OwningIdString(std::string_view str) : IdString(str) { get_reference(); }
+	inline OwningIdString(StaticId id) : IdString(id) {}
+	inline ~OwningIdString() {
+		put_reference();
+	}
+
+	inline OwningIdString &operator=(const OwningIdString &rhs) {
+		put_reference();
+		index_ = rhs.index_;
+		get_reference();
+		return *this;
+	}
+	inline OwningIdString &operator=(const IdString &rhs) {
+		put_reference();
+		index_ = rhs.index_;
+		get_reference();
+		return *this;
+	}
+	inline OwningIdString &operator=(OwningIdString &&rhs) {
+		std::swap(index_, rhs.index_);
+		return *this;
+	}
+
+	// Collect all non-owning references.
+	static void collect_garbage();
+	static int64_t garbage_collection_ns() { return gc_ns; }
+	static int garbage_collection_count() { return gc_count; }
+
+	// Used by the ID() macro to create an IdString with no destructor whose string will
+	// never be released. If ID() creates a closure-static `OwningIdString` then
+	// initialization of the static registers its destructor to run at exit, which is
+	// wasteful.
+	static IdString immortal(const char* str) {
+		IdString result(str);
+		get_reference(result.index_);
+		return result;
+	}
+private:
+	static int64_t gc_ns;
+	static int gc_count;
+
+	void get_reference()
+	{
+		get_reference(index_);
+	}
+	static void get_reference(int idx)
+	{
+	#ifndef YOSYS_NO_IDS_REFCNT
+		if (idx < static_cast<short>(StaticId::STATIC_ID_END))
+			return;
+		auto it = global_refcount_storage_.find(idx);
+		if (it == global_refcount_storage_.end())
+			global_refcount_storage_.insert(it, {idx, 1});
+		else
+			++it->second;
+	#endif
+	#ifdef YOSYS_XTRACE_GET_PUT
+		if (yosys_xtrace && idx >= static_cast<short>(StaticId::STATIC_ID_END))
+			log("#X# GET-BY-INDEX '%s' (index %d, refcount %u)\n", from_index(idx), idx, refcount(idx));
+	#endif
+	}
+
+	void put_reference()
+	{
+	#ifndef YOSYS_NO_IDS_REFCNT
+		// put_reference() may be called from destructors after the destructor of
+		// global_refcount_storage_ has been run. in this case we simply do nothing.
+		if (index_ < static_cast<short>(StaticId::STATIC_ID_END) || !destruct_guard_ok)
+			return;
+	#ifdef YOSYS_XTRACE_GET_PUT
+		if (yosys_xtrace)
+			log("#X# PUT '%s' (index %d, refcount %u)\n", from_index(index_), index_, refcount(index_));
+	#endif
+		auto it = global_refcount_storage_.find(index_);
+		log_assert(it != global_refcount_storage_.end() && it->second >= 1);
+		if (--it->second == 0) {
+			global_refcount_storage_.erase(it);
+		}
+	#endif
+	}
+};
+
 namespace hashlib {
 	template <>
 	struct hash_ops<RTLIL::IdString> {
@@ -501,21 +660,9 @@ inline bool RTLIL::IdString::in(const pool<IdString> &rhs) const { return rhs.co
 [[deprecated]]
 inline bool RTLIL::IdString::in(const pool<IdString> &&rhs) const { return rhs.count(*this) != 0; }
 
-inline bool RTLIL::IdString::operator==(const RTLIL::StaticIdString &rhs) const {
-	return index_ == rhs.index();
-}
-inline bool RTLIL::IdString::operator!=(const RTLIL::StaticIdString &rhs) const {
-	return index_ != rhs.index();
-}
-
 namespace RTLIL {
-	namespace IDInternal {
-#define X(_id) extern const IdString _id;
-#include "kernel/constids.inc"
-#undef X
-	}
 	namespace ID {
-#define X(_id) constexpr StaticIdString _id(StaticId::_id, IDInternal::_id);
+#define X(_id) constexpr IdString _id(StaticId::_id);
 #include "kernel/constids.inc"
 #undef X
 	}
@@ -523,7 +670,7 @@ namespace RTLIL {
 
 struct IdTableEntry {
 	const std::string_view name;
-	const RTLIL::StaticIdString static_id;
+	const RTLIL::IdString static_id;
 };
 
 constexpr IdTableEntry IdTable[] = {
@@ -556,15 +703,15 @@ constexpr int lookup_well_known_id(std::string_view name)
 //
 //  sed -i.orig -r 's/"\\\\([a-zA-Z0-9_]+)"/ID(\1)/g; s/"(\$[a-zA-Z0-9_]+)"/ID(\1)/g;' <filename>
 //
-typedef const RTLIL::IdString &IDMacroHelperFunc();
+typedef RTLIL::IdString IDMacroHelperFunc();
 
 template <int IdTableIndex> struct IDMacroHelper {
-	static constexpr RTLIL::StaticIdString eval(IDMacroHelperFunc) {
+	static constexpr RTLIL::IdString eval(IDMacroHelperFunc) {
 		return IdTable[IdTableIndex].static_id;
 	}
 };
 template <> struct IDMacroHelper<-1> {
-	static constexpr const RTLIL::IdString &eval(IDMacroHelperFunc func) {
+	static constexpr RTLIL::IdString eval(IDMacroHelperFunc func) {
 		return func();
 	}
 };
@@ -574,9 +721,10 @@ template <> struct IDMacroHelper<-1> {
 		YOSYS_NAMESPACE_PREFIX IDMacroHelper< \
 				YOSYS_NAMESPACE_PREFIX lookup_well_known_id(#_id) \
 		>::eval([]() \
-		-> const YOSYS_NAMESPACE_PREFIX RTLIL::IdString & { \
+		-> YOSYS_NAMESPACE_PREFIX RTLIL::IdString { \
 			const char *p = "\\" #_id, *q = p[1] == '$' ? p+1 : p; \
-			static const YOSYS_NAMESPACE_PREFIX RTLIL::IdString id(q); \
+			static const YOSYS_NAMESPACE_PREFIX RTLIL::IdString id = \
+				YOSYS_NAMESPACE_PREFIX RTLIL::OwningIdString::immortal(q); \
 			return id; \
         })
 
@@ -620,13 +768,13 @@ namespace RTLIL {
 
 	template <typename T> struct sort_by_name_str {
 		bool operator()(T *a, T *b) const {
-			return strcmp(a->name.c_str(), b->name.c_str()) < 0;
+			return a->name.lt_by_name(b->name);
 		}
 	};
 
 	struct sort_by_id_str {
 		bool operator()(const RTLIL::IdString &a, const RTLIL::IdString &b) const {
-			return strcmp(a.c_str(), b.c_str()) < 0;
+			return a.lt_by_name(b);
 		}
 	};
 
@@ -1695,9 +1843,7 @@ struct RTLIL::Design
 	// returns all selected unboxed whole modules, warning the user if any
 	// partially selected or boxed modules have been ignored
 	std::vector<RTLIL::Module*> selected_unboxed_whole_modules_warn() const { return selected_modules(SELECT_WHOLE_WARN, SB_UNBOXED_WARN); }
-#ifdef YOSYS_ENABLE_PYTHON
 	static std::map<unsigned int, RTLIL::Design*> *get_all_designs(void);
-#endif
 };
 
 struct RTLIL::Module : public RTLIL::NamedObject

kernel/yosys.cc

@@ -295,35 +295,35 @@ void yosys_shutdown()
 #endif
 }
 
-RTLIL::IdString new_id(std::string file, int line, std::string func)
+const std::string *create_id_prefix(std::string_view file, int line, std::string_view func)
 {
 #ifdef _WIN32
 	size_t pos = file.find_last_of("/\\");
 #else
 	size_t pos = file.find_last_of('/');
 #endif
-	if (pos != std::string::npos)
+	if (pos != std::string_view::npos)
 		file = file.substr(pos+1);
 
 	pos = func.find_last_of(':');
-	if (pos != std::string::npos)
+	if (pos != std::string_view::npos)
 		func = func.substr(pos+1);
 
-	return stringf("$auto$%s:%d:%s$%d", file, line, func, autoidx++);
+	return new std::string(stringf("$auto$%s:%d:%s$", file, line, func));
 }
 
-RTLIL::IdString new_id_suffix(std::string file, int line, std::string func, std::string suffix)
+RTLIL::IdString new_id_suffix(std::string_view file, int line, std::string_view func, std::string_view suffix)
 {
 #ifdef _WIN32
 	size_t pos = file.find_last_of("/\\");
 #else
 	size_t pos = file.find_last_of('/');
 #endif
-	if (pos != std::string::npos)
+	if (pos != std::string_view::npos)
 		file = file.substr(pos+1);
 
 	pos = func.find_last_of(':');
-	if (pos != std::string::npos)
+	if (pos != std::string_view::npos)
 		func = func.substr(pos+1);
 
 	return stringf("$auto$%s:%d:%s$%s$%d", file, line, func, suffix, autoidx++);

kernel/yosys_common.h

@@ -271,11 +271,14 @@ extern int autoidx;
 extern int yosys_xtrace;
 extern bool yosys_write_versions;
 
-RTLIL::IdString new_id(std::string file, int line, std::string func);
-RTLIL::IdString new_id_suffix(std::string file, int line, std::string func, std::string suffix);
+const std::string *create_id_prefix(std::string_view file, int line, std::string_view func);
+RTLIL::IdString new_id_suffix(std::string_view file, int line, std::string_view func, std::string_view suffix);
 
 #define NEW_ID \
-	YOSYS_NAMESPACE_PREFIX new_id(__FILE__, __LINE__, __FUNCTION__)
+	YOSYS_NAMESPACE_PREFIX RTLIL::IdString::new_autoidx_with_prefix([](std::string_view func) -> const std::string * { \
+		static const std::string *prefix = create_id_prefix(__FILE__, __LINE__, func); \
+		return prefix; \
+	}(__FUNCTION__))
 #define NEW_ID_SUFFIX(suffix) \
 	YOSYS_NAMESPACE_PREFIX new_id_suffix(__FILE__, __LINE__, __FUNCTION__, suffix)
 

passes/hierarchy/hierarchy.cc

@@ -156,6 +156,21 @@ std::string basic_cell_type(const std::string celltype, int pos[3] = nullptr) {
 	return basicType;
 }
 
+// Try to read an IdString as a numbered connection name ("$123" or similar),
+// writing the result to dst. If the string isn't of the right format, ignore
+// dst and return false.
+bool read_id_num(RTLIL::IdString str, int *dst)
+{
+	log_assert(dst);
+
+	const char *c_str = str.c_str();
+	if (c_str[0] != '$' || !('0' <= c_str[1] && c_str[1] <= '9'))
+		return false;
+
+	*dst = atoi(c_str + 1);
+	return true;
+}
+
 // A helper struct for expanding a module's interface connections in expand_module
 struct IFExpander
 {
@@ -283,15 +298,42 @@ struct IFExpander
 	                   RTLIL::IdString       conn_name,
 	                   const RTLIL::SigSpec &conn_signals)
 	{
-		// Check if the connection is present as an interface in the sub-module's port list
-		const RTLIL::Wire *wire = submodule.wire(conn_name);
-		if (!wire || !wire->get_bool_attribute(ID::is_interface))
+		// Does the connection look like an interface
+		if (
+			conn_signals.size() != 1 ||
+			conn_signals[0].wire == nullptr ||
+			conn_signals[0].wire->get_bool_attribute(ID::is_interface) == false ||
+			conn_signals[0].wire->name.str().find("$dummywireforinterface") != 0
+		)
 			return;
 
+		// Check if the connection is present as an interface in the sub-module's port list
+		int id;
+		if (read_id_num(conn_name, &id)) {
+			/* Interface expansion is incompatible with positional arguments
+			 * during expansion, the port list gets each interface signal
+			 * inserted after the interface itself which means that the argument
+			 * positions in the parent module no longer match.
+			 *
+			 * Supporting this would require expanding the interfaces in the
+			 * parent module, renumbering the arguments to match, and then
+			 * iterating over the ports list to find the matching interface
+			 * (refactoring on_interface to accept different conn_names on the
+			 * parent and child).
+			 */
+			log_error("Unable to connect `%s' to submodule `%s' with positional interface argument `%s'!\n",
+				module.name,
+				submodule.name,
+				conn_signals[0].wire->name.str().substr(23)
+			);
+		} else {
+			// Lookup connection by name
+			const RTLIL::Wire *wire = submodule.wire(conn_name);
+			if (!wire || !wire->get_bool_attribute(ID::is_interface))
+				return;
+			}
 		// If the connection looks like an interface, handle it.
-		const auto &bits = conn_signals;
-		if (bits.size() == 1 && bits[0].wire->get_bool_attribute(ID::is_interface))
-			on_interface(submodule, conn_name, conn_signals);
+		on_interface(submodule, conn_name, conn_signals);
 	}
 
 	// Iterate over the connections in a cell, tracking any interface
@@ -376,21 +418,6 @@ RTLIL::Module *get_module(RTLIL::Design                  &design,
 	return nullptr;
 }
 
-// Try to read an IdString as a numbered connection name ("$123" or similar),
-// writing the result to dst. If the string isn't of the right format, ignore
-// dst and return false.
-bool read_id_num(RTLIL::IdString str, int *dst)
-{
-	log_assert(dst);
-
-	const char *c_str = str.c_str();
-	if (c_str[0] != '$' || !('0' <= c_str[1] && c_str[1] <= '9'))
-		return false;
-
-	*dst = atoi(c_str + 1);
-	return true;
-}
-
 // Check that the connections on the cell match those that are defined
 // on the type: each named connection should match the name of a port
 // and each positional connection should have an index smaller than

passes/opt/opt_clean.cc

@@ -283,7 +283,7 @@ bool compare_signals(RTLIL::SigBit &s1, RTLIL::SigBit &s2, SigPool &regs, SigPoo
 	if (attrs1 != attrs2)
 		return attrs2 > attrs1;
 
-	return strcmp(w2->name.c_str(), w1->name.c_str()) < 0;
+	return w2->name.lt_by_name(w1->name);
 }
 
 bool check_public_name(RTLIL::IdString id)
@@ -722,6 +722,8 @@ struct OptCleanPass : public Pass {
 		ct_reg.clear();
 		ct_all.clear();
 		log_pop();
+
+		request_garbage_collection();
 	}
 } OptCleanPass;
 
@@ -784,6 +786,8 @@ struct CleanPass : public Pass {
 		keep_cache.reset();
 		ct_reg.clear();
 		ct_all.clear();
+
+		request_garbage_collection();
 	}
 } CleanPass;
 

passes/techmap/abc.cc

@@ -611,7 +611,7 @@ std::string AbcModuleState::remap_name(RTLIL::IdString abc_name, RTLIL::Wire **o
 			}
 		}
 	}
-	return stringf("$abc$%d$%s", map_autoidx, abc_name.c_str()+1);
+	return stringf("$abc$%d$%s", map_autoidx, abc_name.substr(1));
 }
 
 void AbcModuleState::dump_loop_graph(FILE *f, int &nr, dict<int, pool<int>> &edges, pool<int> &workpool, std::vector<int> &in_counts)

passes/techmap/dfflibmap.cc

@@ -127,7 +127,7 @@ static bool parse_next_state(const LibertyAst *cell, const LibertyAst *attr, std
 		return false;
 	}
 
-	auto pin_names = pool<std::string>{};
+	auto pin_names = std::unordered_set<std::string>{};
 	tree.get_pin_names(pin_names);
 
 	// from the `ff` block, we know the flop output signal name for loopback.
@@ -156,7 +156,7 @@ static bool parse_next_state(const LibertyAst *cell, const LibertyAst *attr, std
 		auto pins = std::vector<std::string>(pin_names.begin(), pin_names.end());
 		int lut = 0;
 		for (int n = 0; n < 8; n++) {
-			auto values = dict<std::string, bool>{};
+			auto values = std::unordered_map<std::string, bool>{};
 			values.insert(std::make_pair(pins[0], (n & 1) == 1));
 			values.insert(std::make_pair(pins[1], (n & 2) == 2));
 			values.insert(std::make_pair(ff_output, (n & 4) == 4));

passes/techmap/libparse.cc

@@ -25,9 +25,22 @@
 #include <fstream>
 #include <iostream>
 #include <sstream>
+#include <algorithm>
 
-#ifndef FILTERLIB
+#ifdef FILTERLIB
+#undef log_assert
+void log_assert(bool cond) {
+	if (!cond)
+		fprintf(stderr, "Unspecified assertion failed\n");
+}
+void warn(std::string str) {
+	std::cerr << str;
+}
+#else
 #include "kernel/log.h"
+void warn(std::string str) {
+	Yosys::log_formatted_warning("", str);
+}
 #endif
 
 using namespace Yosys;
@@ -162,13 +175,15 @@ void LibertyAst::dump(FILE *f, sieve &blacklist, sieve &whitelist, std::string i
 		fprintf(f, " ;\n");
 }
 
-#ifndef FILTERLIB
-
 // binary operators excluding ' '
-bool LibertyExpression::is_nice_binop(char c) {
+bool LibertyExpression::char_is_nice_binop(char c) {
 	return c == '*' || c == '&' || c == '^' || c == '+' || c == '|';
 }
 
+bool LibertyExpression::is_binop() {
+	return kind == AND || kind == OR || kind == XOR;
+}
+
 // https://matklad.github.io/2020/04/13/simple-but-powerful-pratt-parsing.html
 LibertyExpression LibertyExpression::parse(Lexer &s, int min_prio) {
 	if (s.empty())
@@ -177,7 +192,7 @@ LibertyExpression LibertyExpression::parse(Lexer &s, int min_prio) {
 	char c = s.peek();
 	auto lhs = LibertyExpression{};
 
-	while (isspace(c)) {
+	while (isspace(c) || c == '"') {
 		if (s.empty())
 			return lhs;
 		s.next();
@@ -191,7 +206,9 @@ LibertyExpression LibertyExpression::parse(Lexer &s, int min_prio) {
 		s.next();
 		lhs = parse(s);
 		if (s.peek() != ')') {
-			log_warning("expected ')' instead of '%c' while parsing Liberty expression '%s'\n", s.peek(), s.full_expr());
+			std::stringstream ss;
+			ss << "expected ')' instead of " << s.peek() << " while parsing Liberty expression '" << s.full_expr() << "'\n";
+			warn(ss.str());
 			return lhs;
 		}
 		s.next();
@@ -200,10 +217,11 @@ LibertyExpression LibertyExpression::parse(Lexer &s, int min_prio) {
 		lhs.kind = Kind::NOT;
 		lhs.children.push_back(parse(s, 7));
 	} else {
-		log_warning("unrecognised character '%c' while parsing Liberty expression '%s'\n", c, s.full_expr());
+		std::stringstream ss;
+		ss << "unrecognised character " << c << " while parsing Liberty expression " << s.full_expr() << "\n";
+		warn(ss.str());
 		return lhs;
 	}
-
 	while (true) {
 		if (s.empty())
 			break;
@@ -246,9 +264,10 @@ LibertyExpression LibertyExpression::parse(Lexer &s, int min_prio) {
 					s.next();
 					c = s.peek();
 				}
-				if (is_nice_binop(c)) {
+				if (char_is_nice_binop(c) || c == ')' || c == '\'' || c == '\"') {
 					// We found a real binop, so this space wasn't an AND
 					// and we just discard it as meaningless whitespace
+					// Tail operators also imply this isn't an AND
 					continue;
 				}
 			} else {
@@ -286,7 +305,7 @@ LibertyExpression LibertyExpression::parse(Lexer &s, int min_prio) {
 	return lhs;
 }
 
-void LibertyExpression::get_pin_names(pool<std::string>& names) {
+void LibertyExpression::get_pin_names(std::unordered_set<std::string>& names) {
 	if (kind == Kind::PIN) {
 		names.insert(name);
 	} else {
@@ -295,7 +314,7 @@ void LibertyExpression::get_pin_names(pool<std::string>& names) {
 	}
 }
 
-bool LibertyExpression::eval(dict<std::string, bool>& values) {
+bool LibertyExpression::eval(std::unordered_map<std::string, bool>& values) {
 	bool result = false;
 	switch (kind) {
 	case Kind::AND:
@@ -324,7 +343,7 @@ bool LibertyExpression::eval(dict<std::string, bool>& values) {
 	return false;
 }
 
-std::string LibertyExpression::str(int indent)
+std::string LibertyExpression::sexpr_str(int indent)
 {
 	std::string prefix;
 	switch (kind) {
@@ -355,16 +374,55 @@ std::string LibertyExpression::str(int indent)
 		if (!first) {
 			prefix += "\n" + std::string(indent + add_indent, ' ');
 		}
-		prefix += child.str(indent + add_indent);
+		prefix += child.sexpr_str(indent + add_indent);
 		first = false;
 	}
 	prefix += ")";
 	return prefix;
 }
 
-#endif
+std::string LibertyExpression::vlog_str()
+{
+	std::string prefix;
+	if (kind != PIN)
+		prefix += "(";
+	if (is_binop()) {
+		log_assert(children.size() == 2);
+		prefix += children[0].vlog_str();
+		switch (kind) {
+			case AND:
+				prefix += "&";
+				break;
+			case OR:
+				prefix += "|";
+				break;
+			case XOR:
+				prefix += "^";
+				break;
+			default:
+				log_assert(false);
+		}
+		prefix += children[1].vlog_str();
+	} else {
+		switch (kind) {
+			case NOT:
+				log_assert(children.size() == 1);
+				prefix += "~";
+				prefix += children[0].vlog_str();
+				break;
+			case PIN:
+				prefix += name;
+				break;
+			default:
+				log_assert(false);
+			}
+	}
+	if (kind != PIN)
+		prefix += ")";
+	return prefix;
+}
 
-int LibertyParser::lexer(std::string &str)
+int LibertyParser::lexer_inner(std::string &str)
 {
 	int c;
 
@@ -390,11 +448,9 @@ int LibertyParser::lexer(std::string &str)
 
 		if (str == "+" || str == "-") {
 			/* Single operator is not an identifier */
-			// fprintf(stderr, "LEX: char >>%s<<\n", str.c_str());
 			return str[0];
 		}
 		else {
-			// fprintf(stderr, "LEX: identifier >>%s<<\n", str.c_str());
 			return 'v';
 		}
 	}
@@ -402,24 +458,25 @@ int LibertyParser::lexer(std::string &str)
 	// if it wasn't an identifer, number of array range,
 	// maybe it's a string?
 	if (c == '"') {
+		f.consume(1);
 		size_t i = 0;
 		while (true) {
 			c = f.peek(i);
 			line += (c == '\n');
-			if (c != '"')
+			if (c != '"' && c != EOF)
 				i += 1;
 			else
 				break;
 		}
 		str.clear();
-#ifdef FILTERLIB
 		f.unget();
-		str.append(f.buffered_data(), f.buffered_data() + i + 2);
-		f.consume(i + 2);
-#else
-		str.append(f.buffered_data(), f.buffered_data() + i);
-		f.consume(i + 1);
+		str.append(f.buffered_data(), f.buffered_data() + i + 1);
+		// Usage in filterlib is expected to retain quotes
+		// but yosys expects to get unquoted
+#ifdef FILTERLIB
+		str = "\"" + str + "\"";
 #endif
+		f.consume(i + 2);
 		return 'v';
 	}
 
@@ -442,13 +499,12 @@ int LibertyParser::lexer(std::string &str)
 			return lexer(str);
 		}
 		f.unget();
-		// fprintf(stderr, "LEX: char >>/<<\n");
 		return '/';             // a single '/' charater.
 	}
 
 	// check for a backslash
 	if (c == '\\') {
-		c = f.get();		
+		c = f.get();
 		if (c == '\r')
 			c = f.get();
 		if (c == '\n') {
@@ -467,14 +523,22 @@ int LibertyParser::lexer(std::string &str)
 
 	// anything else, such as ';' will get passed
 	// through as literal items.
-
-	// if (c >= 32 && c < 255)
-	// 	fprintf(stderr, "LEX: char >>%c<<\n", c);
-	// else
-	// 	fprintf(stderr, "LEX: char %d\n", c);
 	return c;
 }
 
+int LibertyParser::lexer(std::string &str)
+{
+	int ret = lexer_inner(str);
+	// if (ret >= 32 && ret < 255) {
+	// 	fprintf(stdout, "LEX: ret >>%c<<\n", ret);
+	// } else if (ret == 'v') {
+	// 	fprintf(stdout, "LEX: ret v str %s\n", str.c_str());
+	// } else {
+	// 	fprintf(stdout, "LEX: ret %d\n", ret);
+	// }
+	return ret;
+}
+
 void LibertyParser::report_unexpected_token(int tok)
 {
 	std::string eReport;
@@ -545,6 +609,25 @@ void LibertyParser::parse_vector_range(int tok)
 	}
 }
 
+// Consume into out_str any string-ish tokens, seperated with spaces
+// to cope with abuse of the underdefined spec by real world PDKs
+// enabled by proprietary implementations.
+// Sorry.
+int LibertyParser::consume_wrecked_str(int tok, std::string& out_str) {
+	std::string str = "";
+	while (tok != ';' && tok != EOF && tok != 'n') {
+		out_str += " ";
+		if (tok == 'v')
+			out_str += str;
+		else
+			out_str += tok;
+		tok = lexer(str);
+	}
+	if (tok == EOF)
+		error("wrecked string EOF");
+	return tok;
+}
+
 LibertyAst *LibertyParser::parse(bool top_level)
 {
 	std::string str;
@@ -591,7 +674,14 @@ LibertyAst *LibertyParser::parse(bool top_level)
 				if (tok == '[') {
 					parse_vector_range(tok);
 					tok = lexer(str);
+				} else {
+					// Hack for when an expression string is unquoted
+					tok = consume_wrecked_str(tok, ast->value);
 				}
+			} else if (tok == '(') {
+				// Hack for when an expression string is unquoted and starts with
+				// parentheses
+				tok = consume_wrecked_str(tok, ast->value);
 			}
 			while (tok == '+' || tok == '-' || tok == '*' || tok == '/' || tok == '!') {
 				ast->value += tok;
@@ -601,7 +691,7 @@ LibertyAst *LibertyParser::parse(bool top_level)
 				ast->value += str;
 				tok = lexer(str);
 			}
-			
+
 			// In a liberty file, all key : value pairs should end in ';'
 			// However, there are some liberty files in the wild that
 			// just have a newline. We'll be kind and accept a newline
@@ -621,11 +711,11 @@ LibertyAst *LibertyParser::parse(bool top_level)
 					continue;
 				if (tok == ')')
 					break;
-				
+
 				if (tok == '[')
 				{
 					parse_vector_range(tok);
-					continue;           
+					continue;
 				}
 				if (tok == 'n')
 					continue;
@@ -727,42 +817,13 @@ const LibertyAst *find_non_null(const LibertyAst *node, const char *name)
 
 std::string func2vl(std::string str)
 {
-	for (size_t pos = str.find_first_of("\" \t"); pos != std::string::npos; pos = str.find_first_of("\" \t")) {
-		char c_left = pos > 0 ? str[pos-1] : ' ';
-		char c_right = pos+1 < str.size() ? str[pos+1] : ' ';
-		if (std::string("\" \t*+").find(c_left) != std::string::npos)
-			str.erase(pos, 1);
-		else if (std::string("\" \t*+").find(c_right) != std::string::npos)
-			str.erase(pos, 1);
-		else
-			str[pos] = '*';
-	}
-
-	std::vector<size_t> group_start;
-	for (size_t pos = 0; pos < str.size(); pos++) {
-		if (str[pos] == '(')
-			group_start.push_back(pos);
-		if (str[pos] == ')' && group_start.size() > 0) {
-			if (pos+1 < str.size() && str[pos+1] == '\'') {
-				std::string group = str.substr(group_start.back(), pos-group_start.back()+1);
-				str[group_start.back()] = '~';
-				str.replace(group_start.back()+1, group.size(), group);
-				pos++;
-			}
-			group_start.pop_back();
-		}
-		if (str[pos] == '\'' && pos > 0) {
-			size_t start = str.find_last_of("()'*+^&| ", pos-1)+1;
-			std::string group = str.substr(start, pos-start);
-			str[start] = '~';
-			str.replace(start+1, group.size(), group);
-		}
-		if (str[pos] == '*')
-			str[pos] = '&';
-		if (str[pos] == '+')
-			str[pos] = '|';
-	}
+	auto helper = LibertyExpression::Lexer(str);
+	return LibertyExpression::parse(helper).vlog_str();
+}
 
+std::string vlog_identifier(std::string str)
+{
+	str.erase(std::remove(str.begin(), str.end(), '\"'), str.end());
 	return str;
 }
 
@@ -772,11 +833,13 @@ void event2vl(const LibertyAst *ast, std::string &edge, std::string &expr)
 	expr.clear();
 
 	if (ast != NULL) {
-		expr = func2vl(ast->value);
-		if (expr.size() > 0 && expr[0] == '~')
-			edge = "negedge " + expr.substr(1);
+		auto helper = LibertyExpression::Lexer(ast->value);
+		auto parsed = LibertyExpression::parse(helper);
+		expr = parsed.vlog_str();
+		if (parsed.kind == LibertyExpression::Kind::NOT)
+			edge = "negedge " + parsed.children[0].vlog_str();
 		else
-			edge = "posedge " + expr;
+			edge = "posedge " + parsed.vlog_str();
 	}
 }
 
@@ -806,13 +869,13 @@ void gen_verilogsim_cell(const LibertyAst *ast)
 		return;
 
 	CHECK_NV(ast->args.size(), == 1);
-	printf("module %s (", ast->args[0].c_str());
+	printf("module %s (", vlog_identifier(ast->args[0]).c_str());
 	bool first = true;
 	for (auto child : ast->children) {
 		if (child->id != "pin")
 			continue;
 		CHECK_NV(child->args.size(), == 1);
-		printf("%s%s", first ? "" : ", ", child->args[0].c_str());
+		printf("%s%s", first ? "" : ", ", vlog_identifier(child->args[0]).c_str());
 		first = false;
 	}
 	printf(");\n");
@@ -823,7 +886,7 @@ void gen_verilogsim_cell(const LibertyAst *ast)
 		printf("  reg ");
 		first = true;
 		for (auto arg : child->args) {
-			printf("%s%s", first ? "" : ", ", arg.c_str());
+			printf("%s%s", first ? "" : ", ", vlog_identifier(arg).c_str());
 			first = false;
 		}
 		printf(";\n");
@@ -835,9 +898,10 @@ void gen_verilogsim_cell(const LibertyAst *ast)
 		CHECK_NV(child->args.size(), == 1);
 		const LibertyAst *dir = find_non_null(child, "direction");
 		const LibertyAst *func = child->find("function");
-		printf("  %s %s;\n", dir->value.c_str(), child->args[0].c_str());
+		std::string var = vlog_identifier(child->args[0]);
+		printf("  %s %s;\n", dir->value.c_str(), var.c_str());
 		if (func != NULL)
-			printf("  assign %s = %s; // %s\n", child->args[0].c_str(), func2vl(func->value).c_str(), func->value.c_str());
+			printf("  assign %s = %s; // %s\n", var.c_str(), func2vl(func->value).c_str(), func->value.c_str());
 	}
 
 	for (auto child : ast->children)
@@ -845,8 +909,8 @@ void gen_verilogsim_cell(const LibertyAst *ast)
 		if (child->id != "ff" || child->args.size() != 2)
 			continue;
 
-		std::string iq_var = child->args[0];
-		std::string iqn_var = child->args[1];
+		std::string iq_var = vlog_identifier(child->args[0]);
+		std::string iqn_var = vlog_identifier(child->args[1]);
 
 		std::string clock_edge, clock_expr;
 		event2vl(child->find("clocked_on"), clock_edge, clock_expr);
@@ -909,8 +973,8 @@ void gen_verilogsim_cell(const LibertyAst *ast)
 		if (child->id != "latch" || child->args.size() != 2)
 			continue;
 
-		std::string iq_var = child->args[0];
-		std::string iqn_var = child->args[1];
+		std::string iq_var = vlog_identifier(child->args[0]);
+		std::string iqn_var = vlog_identifier(child->args[1]);
 
 		std::string enable_edge, enable_expr;
 		event2vl(child->find("enable"), enable_edge, enable_expr);

passes/techmap/libparse.h

@@ -63,7 +63,7 @@ namespace Yosys
 			}
 
 			std::string pin() {
-				auto length = s.find_first_of("\t()'!^*& +|");
+				auto length = s.find_first_of("\t()'!^*& +|\"");
 				if (length == std::string::npos) {
 					// nothing found so use size of s
 					length = s.size();
@@ -91,11 +91,13 @@ namespace Yosys
 		LibertyExpression() : kind(Kind::EMPTY) {}
 
 		static LibertyExpression parse(Lexer &s, int min_prio = 0);
-		void get_pin_names(pool<std::string>& names);
-		bool eval(dict<std::string, bool>& values);
-		std::string str(int indent = 0);
+		void get_pin_names(std::unordered_set<std::string>& names);
+		bool eval(std::unordered_map<std::string, bool>& values);
+		std::string sexpr_str(int indent = 0);
+		std::string vlog_str();
 	private:
-		static bool is_nice_binop(char c);
+		static bool char_is_nice_binop(char c);
+		bool is_binop();
 	};
 
 	class LibertyInputStream {
@@ -170,10 +172,12 @@ namespace Yosys
 		   'n': newline
 		   anything else is a single character.
 		*/
+		int lexer_inner(std::string &str);
 		int lexer(std::string &str);
 
 		void report_unexpected_token(int tok);
 		void parse_vector_range(int tok);
+		int consume_wrecked_str(int tok, std::string& out_str);
 		LibertyAst *parse(bool top_level);
 		void error() const;
 		void error(const std::string &str) const;

pyosys/generator.py

@@ -164,6 +164,8 @@ pyosys_headers = [
                     {
                         "global_id_storage_",
                         "global_id_index_",
+                        "global_negative_id_storage_",
+                        "global_negative_id_prefix_storage_",
                         "global_refcount_storage_",
                         "global_free_idx_list_",
                         "last_created_idx_ptr_",

tests/arch/quicklogic/pp3/fsm.ys

@@ -11,8 +11,6 @@ sat -verify -prove-asserts -show-public -set-at 1 in_reset 1 -seq 20 -prove-skip
 design -load postopt # load the post-opt design (otherwise equiv_opt loads the pre-opt design)
 cd fsm # Constrain all select calls below inside the top module
 
-select -assert-count 2 t:LUT2
-select -assert-count 4 t:LUT3
 select -assert-count 4 t:dffepc
 select -assert-count 1 t:logic_0
 select -assert-count 1 t:logic_1

tests/arch/xilinx/dsp_cascade.ys

@@ -69,7 +69,8 @@ equiv_opt -assert -map +/xilinx/cells_sim.v synth_xilinx -noiopad
 design -load postopt
 cd cascade
 select -assert-count 2 t:DSP48E1
-select -assert-none t:DSP48E1 t:BUFG %% t:* %D
+# TODO Disabled check, FDREs emitted due to order sensitivity
+# select -assert-none t:DSP48E1 t:BUFG %% t:* %D
 # Very crude method of checking that DSP48E1.PCOUT -> DSP48E1.PCIN
 #   (see above for explanation)
 select -assert-count 1 t:DSP48E1 %co:+[PCOUT] t:DSP48E1 %d %co:+[PCIN] w:* %d t:DSP48E1 %i

tests/liberty/XNOR2X1.lib.verilogsim.ok

@@ -2,5 +2,5 @@ module XNOR2X1 (B, A, Y);
   input B;
   input A;
   output Y;
-  assign Y = !(B&!A|!B&A); // "!(B&!A|!B&A)"
+  assign Y = (~((B&(~A))|((~B)&A))); // "!(B&!A|!B&A)"
 endmodule

tests/liberty/dff.lib

@@ -5,7 +5,7 @@ library(dff) {
     area : 1;
     ff("IQ", "IQN") {
       next_state : "(D)";
-      clocked_on : "CLK";
+      clocked_on : (CLK);
     } 
     pin(D) {
       direction : input;
@@ -15,7 +15,7 @@ library(dff) {
     }
     pin(Q) {
       direction: output;
-      function : "IQ";   
+      function : IQ;   
     }
   }
 

tests/liberty/dff.lib.filtered.ok

@@ -3,7 +3,7 @@ library(dff) {
     area : 1 ;
     ff("IQ", "IQN") {
       next_state : "(D)" ;
-      clocked_on : "CLK" ;
+      clocked_on :  ( CLK ) ;
     }
     pin(D) {
       direction : input ;
@@ -13,7 +13,7 @@ library(dff) {
     }
     pin(Q) {
       direction : output ;
-      function : "IQ" ;
+      function : IQ ;
     }
   }
 }

tests/liberty/dff.lib.verilogsim.ok

@@ -1,12 +1,12 @@
 module dff (D, CLK, Q);
-  reg "IQ", "IQN";
+  reg IQ, IQN;
   input D;
   input CLK;
   output Q;
-  assign Q = IQ; // "IQ"
+  assign Q = IQ; // IQ
   always @(posedge CLK) begin
       // "(D)"
-      "IQ" <= (D);
-      "IQN" <= ~((D));
+      IQ <= D;
+      IQN <= ~(D);
   end
 endmodule

tests/liberty/normal.lib.verilogsim.ok

@@ -1,13 +1,13 @@
 module inv (A, Y);
   input A;
   output Y;
-  assign Y = ~A; // "A'"
+  assign Y = (~A); // "A'"
 endmodule
 module tri_inv (A, S, Z);
   input A;
   input S;
   output Z;
-  assign Z = ~A; // "A'"
+  assign Z = (~A); // "A'"
 endmodule
 module buffer (A, Y);
   input A;
@@ -18,29 +18,29 @@ module nand2 (A, B, Y);
   input A;
   input B;
   output Y;
-  assign Y = ~(A&B); // "(A * B)'"
+  assign Y = (~(A&B)); // "(A * B)'"
 endmodule
 module nor2 (A, B, Y);
   input A;
   input B;
   output Y;
-  assign Y = ~(A|B); // "(A + B)'"
+  assign Y = (~(A|B)); // "(A + B)'"
 endmodule
 module xor2 (A, B, Y);
   input A;
   input B;
   output Y;
-  assign Y = (A&~B)|(~A&B); // "(A *B') + (A' * B)"
+  assign Y = ((A&(~B))|((~A)&B)); // "(A *B') + (A' * B)"
 endmodule
 module imux2 (A, B, S, Y);
   input A;
   input B;
   input S;
   output Y;
-  assign Y = ~(&(A&S)|(B&~S)&); // "( (A * S) + (B * S') )'"
+  assign Y = (~((A&S)|(B&(~S)))); // "( (A * S) + (B * S') )'"
 endmodule
 module dff (D, CLK, RESET, PRESET, Q, QN);
-  reg "IQ", "IQN";
+  reg IQ, IQN;
   input D;
   input CLK;
   input RESET;
@@ -51,26 +51,26 @@ module dff (D, CLK, RESET, PRESET, Q, QN);
   assign QN = IQN; // "IQN"
   always @(posedge CLK, posedge RESET, posedge PRESET) begin
     if ((RESET) && (PRESET)) begin
-      "IQ" <= 0;
-      "IQN" <= 0;
+      IQ <= 0;
+      IQN <= 0;
     end
     else if (RESET) begin
-      "IQ" <= 0;
-      "IQN" <= 1;
+      IQ <= 0;
+      IQN <= 1;
     end
     else if (PRESET) begin
-      "IQ" <= 1;
-      "IQN" <= 0;
+      IQ <= 1;
+      IQN <= 0;
     end
     else begin
       // "D"
-      "IQ" <= D;
-      "IQN" <= ~(D);
+      IQ <= D;
+      IQN <= ~(D);
     end
   end
 endmodule
 module latch (D, G, Q, QN);
-  reg "IQ", "IQN";
+  reg IQ, IQN;
   input D;
   input G;
   output Q;
@@ -79,8 +79,8 @@ module latch (D, G, Q, QN);
   assign QN = IQN; // "IQN"
   always @* begin
     if (G) begin
-      "IQ" <= D;
-      "IQN" <= ~(D);
+      IQ <= D;
+      IQN <= ~(D);
     end
   end
 endmodule
@@ -89,14 +89,14 @@ module aoi211 (A, B, C, Y);
   input B;
   input C;
   output Y;
-  assign Y = ~((A&B)|C); // "((A * B) + C)'"
+  assign Y = (~((A&B)|C)); // "((A * B) + C)'"
 endmodule
 module oai211 (A, B, C, Y);
   input A;
   input B;
   input C;
   output Y;
-  assign Y = ~((A|B)&C); // "((A + B) * C)'"
+  assign Y = (~((A|B)&C)); // "((A + B) * C)'"
 endmodule
 module halfadder (A, B, C, Y);
   input A;
@@ -104,7 +104,7 @@ module halfadder (A, B, C, Y);
   output C;
   assign C = (A&B); // "(A * B)"
   output Y;
-  assign Y = (A&~B)|(~A&B); // "(A *B') + (A' * B)"
+  assign Y = ((A&(~B))|((~A)&B)); // "(A *B') + (A' * B)"
 endmodule
 module fulladder (A, B, CI, CO, Y);
   input A;

tests/liberty/unquoted.lib

@@ -0,0 +1,60 @@
+library(dff_unquoted) {
+  cell (dff1) {
+    area : 1;
+    ff("IQ", "IQN") {
+      next_state : !D;
+      clocked_on : (CLK);
+    }
+    pin(D) {
+      direction : input;
+    }
+    pin(CLK) {
+      direction : input;
+    }
+    pin(Q) {
+      direction: output;
+      function : IQ;
+    }
+  }
+  cell (dff2) {
+    area : 1;
+    ff(IQ, IQN) {
+      next_state : D';
+      clocked_on : CLK;
+    }
+    pin(D) {
+      direction : input;
+    }
+    pin(CLK) {
+      direction : input;
+    }
+    pin(Q) {
+      direction: output;
+      function : "IQ";
+    }
+  }
+  cell (dffe) {
+    area : 6;
+    ff("IQ", "IQN") {
+      next_state : (D&EN) | (IQ&!EN);
+      clocked_on : !CLK;
+    }
+    pin(D) {
+      direction : input;
+    }
+    pin(EN) {
+      direction : input;
+    }
+    pin(CLK) {
+      direction : input;
+    }
+    pin(Q) {
+      direction: output;
+      function : "IQ";
+    }
+    pin(QN) {
+      direction: output;
+      function : "IQN";
+    }
+  }
+}

tests/liberty/unquoted.lib.filtered.ok

@@ -0,0 +1,60 @@
+library(dff_unquoted) {
+  cell(dff1) {
+    area : 1 ;
+    ff("IQ", "IQN") {
+      next_state : !D ;
+      clocked_on :  ( CLK ) ;
+    }
+    pin(D) {
+      direction : input ;
+    }
+    pin(CLK) {
+      direction : input ;
+    }
+    pin(Q) {
+      direction : output ;
+      function : IQ ;
+    }
+  }
+  cell(dff2) {
+    area : 1 ;
+    ff(IQ, IQN) {
+      next_state : D ' ;
+      clocked_on : CLK ;
+    }
+    pin(D) {
+      direction : input ;
+    }
+    pin(CLK) {
+      direction : input ;
+    }
+    pin(Q) {
+      direction : output ;
+      function : "IQ" ;
+    }
+  }
+  cell(dffe) {
+    area : 6 ;
+    ff("IQ", "IQN") {
+      next_state :  ( D & EN ) | ( IQ & ! EN ) ;
+      clocked_on : !CLK ;
+    }
+    pin(D) {
+      direction : input ;
+    }
+    pin(EN) {
+      direction : input ;
+    }
+    pin(CLK) {
+      direction : input ;
+    }
+    pin(Q) {
+      direction : output ;
+      function : "IQ" ;
+    }
+    pin(QN) {
+      direction : output ;
+      function : "IQN" ;
+    }
+  }
+}

tests/liberty/unquoted.lib.verilogsim.ok

@@ -0,0 +1,39 @@
+module dff1 (D, CLK, Q);
+  reg IQ, IQN;
+  input D;
+  input CLK;
+  output Q;
+  assign Q = IQ; // IQ
+  always @(posedge CLK) begin
+      // !D
+      IQ <= (~D);
+      IQN <= ~((~D));
+  end
+endmodule
+module dff2 (D, CLK, Q);
+  reg IQ, IQN;
+  input D;
+  input CLK;
+  output Q;
+  assign Q = IQ; // "IQ"
+  always @(posedge CLK) begin
+      // D '
+      IQ <= (~D);
+      IQN <= ~((~D));
+  end
+endmodule
+module dffe (D, EN, CLK, Q, QN);
+  reg IQ, IQN;
+  input D;
+  input EN;
+  input CLK;
+  output Q;
+  assign Q = IQ; // "IQ"
+  output QN;
+  assign QN = IQN; // "IQN"
+  always @(negedge CLK) begin
+      //  ( D & EN ) | ( IQ & ! EN )
+      IQ <= ((D&EN)|(IQ&(~EN)));
+      IQN <= ~(((D&EN)|(IQ&(~EN))));
+  end
+endmodule

tests/svinterfaces/positional_args.ys

@@ -0,0 +1,33 @@
+read_verilog -sv << EOF
+interface simple_if;
+    logic receiver;
+    logic driver;
+endinterface
+
+module driver_mod(simple_if intf, input in);
+    assign intf.driver = in;
+endmodule
+
+module receiver_mod(simple_if intf);
+    assign intf.receiver = intf.driver;
+endmodule
+
+module top(
+    input logic [1:0] inputs,
+    output logic [1:0] outputs
+);
+    simple_if intf0();
+    simple_if intf1();
+
+    driver_mod d0(intf0, inputs[0]);
+    driver_mod d1(intf1, inputs[1]);
+
+    receiver_mod r0(intf0);
+    receiver_mod r1(intf1);
+
+    assign outputs = {intf0.receiver, intf1.receiver};
+endmodule
+EOF
+
+logger -expect error "Unable to connect.* with positional interface" 1
+hierarchy -top top

tests/svinterfaces/run-test.sh

@@ -5,3 +5,4 @@
 
 ./run_simple.sh load_and_derive
 ./run_simple.sh resolve_types
+./run_simple.sh positional_args

tests/unit/Makefile

@@ -30,11 +30,11 @@ TESTS := $(addprefix $(BINTEST)/, $(basename $(ALLTESTFILE:%Test.cc=%Test.o)))
 
 all: prepare $(TESTS) run-tests
 
-$(BINTEST)/%: $(OBJTEST)/%.o
+$(BINTEST)/%: $(OBJTEST)/%.o | prepare
 	$(CXX) -L$(ROOTPATH) $(RPATH) $(LINKFLAGS) -o $@ $^ $(LIBS) \
 		$(GTEST_LDFLAGS) $(EXTRAFLAGS)
 
-$(OBJTEST)/%.o: $(basename $(subst $(OBJTEST),.,%)).cc
+$(OBJTEST)/%.o: $(basename $(subst $(OBJTEST),.,%)).cc | prepare
 	$(CXX) -o $@ -c -I$(ROOTPATH) $(CPPFLAGS) $(CXXFLAGS) $(GTEST_CXXFLAGS) $^
 
 .PHONY: prepare run-tests clean

tests/unit/kernel/rtlilTest.cc

@@ -361,6 +361,36 @@ namespace RTLIL {
 		EXPECT_FALSE(Const().is_onehot(&pos));
 	}
 
+	TEST_F(KernelRtlilTest, OwningIdString) {
+		OwningIdString own("\\figblortle");
+		OwningIdString::collect_garbage();
+		EXPECT_EQ(own.str(), "\\figblortle");
+	}
+
+	TEST_F(KernelRtlilTest, LookupAutoidxId) {
+		IdString id = NEW_ID;
+		IdString id2 = IdString(id.str());
+		EXPECT_EQ(id, id2);
+	}
+
+	TEST_F(KernelRtlilTest, NewIdBeginsWith) {
+		IdString id = NEW_ID;
+		EXPECT_TRUE(id.begins_with("$auto"));
+		EXPECT_FALSE(id.begins_with("xyz"));
+		EXPECT_TRUE(id.begins_with("$auto$"));
+		EXPECT_FALSE(id.begins_with("abcdefghijklmn"));
+		EXPECT_TRUE(id.begins_with("$auto$rtlilTest"));
+		EXPECT_FALSE(id.begins_with("$auto$rtlilX"));
+	}
+
+	TEST_F(KernelRtlilTest, NewIdIndexing) {
+		IdString id = NEW_ID;
+		std::string str = id.str();
+		for (int i = 0; i < GetSize(str) + 1; ++i) {
+			EXPECT_EQ(id[i], str.c_str()[i]);
+		}
+	}
+
 	class WireRtlVsHdlIndexConversionTest :
 		public KernelRtlilTest,
 		public testing::WithParamInterface<std::tuple<bool, int, int>>

tests/unit/techmap/libparseTest.cc

@@ -13,7 +13,7 @@ namespace RTLIL {
 		void checkAll(std::initializer_list<std::string> expressions, std::string expected) {
 			for (const auto& e : expressions) {
 				auto helper = LibertyExpression::Lexer(e);
-				auto tree_s = LibertyExpression::parse(helper).str();
+				auto tree_s = LibertyExpression::parse(helper).sexpr_str();
 				EXPECT_EQ(tree_s, expected);
 			}
 		}
@@ -82,6 +82,11 @@ namespace RTLIL {
 		}, "(and (pin \"x\")\n"
 		   "     (not (pin \"y\")))"
 		);
+		checkAll({
+			"( D & EN )",
+		}, "(and (pin \"D\")\n"
+		   "     (pin \"EN\"))"
+		);
 	}
 }