Merge remote-tracking branch 'origin/master' into eddie/verific_help

11 files changed, 347 insertions, 229 deletions

diff --git a/frontends/aiger/aigerparse.cc b/frontends/aiger/aigerparse.cc
index cf060193d..a4b1e6fec 100644
--- a/frontends/aiger/aigerparse.cc
+++ b/frontends/aiger/aigerparse.cc
@@ -206,7 +206,7 @@ eval_end:
 };
 
 AigerReader::AigerReader(RTLIL::Design *design, std::istream &f, RTLIL::IdString module_name, RTLIL::IdString clk_name, std::string map_filename, bool wideports)
-	: design(design), f(f), clk_name(clk_name), map_filename(map_filename), wideports(wideports)
+	: design(design), f(f), clk_name(clk_name), map_filename(map_filename), wideports(wideports), aiger_autoidx(autoidx++)
 {
 	module = new RTLIL::Module;
 	module->name = module_name;
@@ -255,7 +255,7 @@ end_of_header:
 	else
 		log_abort();
 
-	RTLIL::Wire* n0 = module->wire("\\__0__");
+	RTLIL::Wire* n0 = module->wire(stringf("$aiger%d$0", aiger_autoidx));
 	if (n0)
 		module->connect(n0, State::S0);
 
@@ -271,14 +271,24 @@ end_of_header:
 			if ((c == 'i' && l1 > inputs.size()) || (c == 'l' && l1 > latches.size()) || (c == 'o' && l1 > outputs.size()))
 				log_error("Line %u has invalid symbol position!\n", line_count);
 
+			RTLIL::IdString escaped_s = stringf("\\%s", s.c_str());
 			RTLIL::Wire* wire;
 			if (c == 'i') wire = inputs[l1];
 			else if (c == 'l') wire = latches[l1];
-			else if (c == 'o') wire = outputs[l1];
+			else if (c == 'o') {
+				wire = module->wire(escaped_s);
+				if (wire) {
+					// Could have been renamed by a latch
+					module->swap_names(wire, outputs[l1]);
+					module->connect(outputs[l1], wire);
+					goto next;
+				}
+				wire = outputs[l1];
+			}
 			else if (c == 'b') wire = bad_properties[l1];
 			else log_abort();
 
-			module->rename(wire, stringf("\\%s", s.c_str()));
+			module->rename(wire, escaped_s);
 		}
 		else if (c == 'j' || c == 'f') {
 			// TODO
@@ -293,6 +303,7 @@ end_of_header:
 		}
 		else
 			log_error("Line %u: cannot interpret first character '%c'!\n", line_count, c);
+next:
 		std::getline(f, line); // Ignore up to start of next line
 	}
 
@@ -312,18 +323,18 @@ static uint32_t parse_xaiger_literal(std::istream &f)
 	return from_big_endian(l);
 }
 
-static RTLIL::Wire* createWireIfNotExists(RTLIL::Module *module, unsigned literal)
+RTLIL::Wire* AigerReader::createWireIfNotExists(RTLIL::Module *module, unsigned literal)
 {
 	const unsigned variable = literal >> 1;
 	const bool invert = literal & 1;
-	RTLIL::IdString wire_name(stringf("\\__%d%s__", variable, invert ? "b" : ""));
+	RTLIL::IdString wire_name(stringf("$aiger%d$%d%s", aiger_autoidx, variable, invert ? "b" : ""));
 	RTLIL::Wire *wire = module->wire(wire_name);
 	if (wire) return wire;
 	log_debug2("Creating %s\n", wire_name.c_str());
 	wire = module->addWire(wire_name);
 	wire->port_input = wire->port_output = false;
 	if (!invert) return wire;
-	RTLIL::IdString wire_inv_name(stringf("\\__%d__", variable));
+	RTLIL::IdString wire_inv_name(stringf("$aiger%d$%d", aiger_autoidx, variable));
 	RTLIL::Wire *wire_inv = module->wire(wire_inv_name);
 	if (wire_inv) {
 		if (module->cell(wire_inv_name)) return wire;
@@ -335,12 +346,12 @@ static RTLIL::Wire* createWireIfNotExists(RTLIL::Module *module, unsigned litera
 	}
 
 	log_debug2("Creating %s = ~%s\n", wire_name.c_str(), wire_inv_name.c_str());
-	module->addNotGate(stringf("\\__%d__$not", variable), wire_inv, wire);
+	module->addNotGate(stringf("$not$aiger%d$%d", aiger_autoidx, variable), wire_inv, wire);
 
 	return wire;
 }
 
-void AigerReader::parse_xaiger(const dict<int,IdString> &box_lookup)
+void AigerReader::parse_xaiger()
 {
 	std::string header;
 	f >> header;
@@ -372,108 +383,118 @@ void AigerReader::parse_xaiger(const dict<int,IdString> &box_lookup)
 	else
 		log_abort();
 
-	RTLIL::Wire* n0 = module->wire("\\__0__");
+	RTLIL::Wire* n0 = module->wire(stringf("$aiger%d$0", aiger_autoidx));
 	if (n0)
 		module->connect(n0, State::S0);
 
+	int c = f.get();
+	if (c != 'c')
+		log_error("Line %u: cannot interpret first character '%c'!\n", line_count, c);
+	if (f.peek() == '\n')
+		f.get();
+
+	dict<int,IdString> box_lookup;
+	for (auto m : design->modules()) {
+		auto it = m->attributes.find(ID(abc9_box_id));
+		if (it == m->attributes.end())
+			continue;
+		if (m->name.begins_with("$paramod"))
+			continue;
+		auto id = it->second.as_int();
+		auto r = box_lookup.insert(std::make_pair(id, m->name));
+		if (!r.second)
+			log_error("Module '%s' has the same abc9_box_id = %d value as '%s'.\n",
+					log_id(m), id, log_id(r.first->second));
+		log_assert(r.second);
+	}
+
 	// Parse footer (symbol table, comments, etc.)
 	std::string s;
-	bool comment_seen = false;
-	for (int c = f.peek(); c != EOF; c = f.peek()) {
-		if (comment_seen || c == 'c') {
-			if (!comment_seen) {
-				f.ignore(1);
-				c = f.peek();
-				comment_seen = true;
-			}
-			if (c == '\n')
-				break;
-			f.ignore(1);
-			// XAIGER extensions
-			if (c == 'm') {
-				uint32_t dataSize YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
-				uint32_t lutNum = parse_xaiger_literal(f);
-				uint32_t lutSize YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
-				log_debug("m: dataSize=%u lutNum=%u lutSize=%u\n", dataSize, lutNum, lutSize);
-				ConstEvalAig ce(module);
-				for (unsigned i = 0; i < lutNum; ++i) {
-					uint32_t rootNodeID = parse_xaiger_literal(f);
-					uint32_t cutLeavesM = parse_xaiger_literal(f);
-					log_debug2("rootNodeID=%d cutLeavesM=%d\n", rootNodeID, cutLeavesM);
-					RTLIL::Wire *output_sig = module->wire(stringf("\\__%d__", rootNodeID));
-					uint32_t nodeID;
-					RTLIL::SigSpec input_sig;
-					for (unsigned j = 0; j < cutLeavesM; ++j) {
-						nodeID = parse_xaiger_literal(f);
-						log_debug2("\t%u\n", nodeID);
-						RTLIL::Wire *wire = module->wire(stringf("\\__%d__", nodeID));
-						log_assert(wire);
-						input_sig.append(wire);
-					}
-					// TODO: Compute LUT mask from AIG in less than O(2 ** input_sig.size())
-					ce.clear();
-					ce.compute_deps(output_sig, input_sig.to_sigbit_pool());
-					RTLIL::Const lut_mask(RTLIL::State::Sx, 1 << input_sig.size());
-					for (int j = 0; j < (1 << cutLeavesM); ++j) {
-						int gray = j ^ (j >> 1);
-						ce.set_incremental(input_sig, RTLIL::Const{gray, static_cast<int>(cutLeavesM)});
-						RTLIL::SigBit o(output_sig);
-						bool success YS_ATTRIBUTE(unused) = ce.eval(o);
-						log_assert(success);
-						log_assert(o.wire == nullptr);
-						lut_mask[gray] = o.data;
-					}
-					RTLIL::Cell *output_cell = module->cell(stringf("\\__%d__$and", rootNodeID));
-					log_assert(output_cell);
-					module->remove(output_cell);
-					module->addLut(stringf("\\__%d__$lut", rootNodeID), input_sig, output_sig, std::move(lut_mask));
+	for (int c = f.get(); c != EOF; c = f.get()) {
+		// XAIGER extensions
+		if (c == 'm') {
+			uint32_t dataSize YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
+			uint32_t lutNum = parse_xaiger_literal(f);
+			uint32_t lutSize YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
+			log_debug("m: dataSize=%u lutNum=%u lutSize=%u\n", dataSize, lutNum, lutSize);
+			ConstEvalAig ce(module);
+			for (unsigned i = 0; i < lutNum; ++i) {
+				uint32_t rootNodeID = parse_xaiger_literal(f);
+				uint32_t cutLeavesM = parse_xaiger_literal(f);
+				log_debug2("rootNodeID=%d cutLeavesM=%d\n", rootNodeID, cutLeavesM);
+				RTLIL::Wire *output_sig = module->wire(stringf("$aiger%d$%d", aiger_autoidx, rootNodeID));
+				log_assert(output_sig);
+				uint32_t nodeID;
+				RTLIL::SigSpec input_sig;
+				for (unsigned j = 0; j < cutLeavesM; ++j) {
+					nodeID = parse_xaiger_literal(f);
+					log_debug2("\t%u\n", nodeID);
+					RTLIL::Wire *wire = module->wire(stringf("$aiger%d$%d", aiger_autoidx, nodeID));
+					log_assert(wire);
+					input_sig.append(wire);
 				}
-			}
-			else if (c == 'r') {
-				uint32_t dataSize YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
-				flopNum = parse_xaiger_literal(f);
-				log_debug("flopNum: %u\n", flopNum);
-				log_assert(dataSize == (flopNum+1) * sizeof(uint32_t));
-				f.ignore(flopNum * sizeof(uint32_t));
-			}
-			else if (c == 'n') {
-				parse_xaiger_literal(f);
-				f >> s;
-				log_debug("n: '%s'\n", s.c_str());
-			}
-			else if (c == 'h') {
-				f.ignore(sizeof(uint32_t));
-				uint32_t version YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
-				log_assert(version == 1);
-				uint32_t ciNum YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
-				log_debug("ciNum = %u\n", ciNum);
-				uint32_t coNum YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
-				log_debug("coNum = %u\n", coNum);
-				piNum = parse_xaiger_literal(f);
-				log_debug("piNum = %u\n", piNum);
-				uint32_t poNum YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
-				log_debug("poNum = %u\n", poNum);
-				uint32_t boxNum = parse_xaiger_literal(f);
-				log_debug("boxNum = %u\n", boxNum);
-				for (unsigned i = 0; i < boxNum; i++) {
-					f.ignore(2*sizeof(uint32_t));
-					uint32_t boxUniqueId = parse_xaiger_literal(f);
-					log_assert(boxUniqueId > 0);
-					uint32_t oldBoxNum = parse_xaiger_literal(f);
-					RTLIL::Cell* cell = module->addCell(stringf("$__box%u__", oldBoxNum), box_lookup.at(boxUniqueId));
-					boxes.emplace_back(cell);
+				// TODO: Compute LUT mask from AIG in less than O(2 ** input_sig.size())
+				ce.clear();
+				ce.compute_deps(output_sig, input_sig.to_sigbit_pool());
+				RTLIL::Const lut_mask(RTLIL::State::Sx, 1 << input_sig.size());
+				for (int j = 0; j < (1 << cutLeavesM); ++j) {
+					int gray = j ^ (j >> 1);
+					ce.set_incremental(input_sig, RTLIL::Const{gray, static_cast<int>(cutLeavesM)});
+					RTLIL::SigBit o(output_sig);
+					bool success YS_ATTRIBUTE(unused) = ce.eval(o);
+					log_assert(success);
+					log_assert(o.wire == nullptr);
+					lut_mask[gray] = o.data;
 				}
+				RTLIL::Cell *output_cell = module->cell(stringf("$and$aiger%d$%d", aiger_autoidx, rootNodeID));
+				log_assert(output_cell);
+				module->remove(output_cell);
+				module->addLut(stringf("$lut$aiger%d$%d", aiger_autoidx, rootNodeID), input_sig, output_sig, std::move(lut_mask));
 			}
-			else if (c == 'a' || c == 'i' || c == 'o') {
-				uint32_t dataSize = parse_xaiger_literal(f);
-				f.ignore(dataSize);
-			}
-			else {
-				break;
+		}
+		else if (c == 'r') {
+			uint32_t dataSize YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
+			flopNum = parse_xaiger_literal(f);
+			log_debug("flopNum = %u\n", flopNum);
+			log_assert(dataSize == (flopNum+1) * sizeof(uint32_t));
+			f.ignore(flopNum * sizeof(uint32_t));
+		}
+		else if (c == 'n') {
+			parse_xaiger_literal(f);
+			f >> s;
+			log_debug("n: '%s'\n", s.c_str());
+		}
+		else if (c == 'h') {
+			f.ignore(sizeof(uint32_t));
+			uint32_t version YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
+			log_assert(version == 1);
+			uint32_t ciNum YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
+			log_debug("ciNum = %u\n", ciNum);
+			uint32_t coNum YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
+			log_debug("coNum = %u\n", coNum);
+			piNum = parse_xaiger_literal(f);
+			log_debug("piNum = %u\n", piNum);
+			uint32_t poNum YS_ATTRIBUTE(unused) = parse_xaiger_literal(f);
+			log_debug("poNum = %u\n", poNum);
+			uint32_t boxNum = parse_xaiger_literal(f);
+			log_debug("boxNum = %u\n", boxNum);
+			for (unsigned i = 0; i < boxNum; i++) {
+				f.ignore(2*sizeof(uint32_t));
+				uint32_t boxUniqueId = parse_xaiger_literal(f);
+				log_assert(boxUniqueId > 0);
+				uint32_t oldBoxNum = parse_xaiger_literal(f);
+				RTLIL::Cell* cell = module->addCell(stringf("$box%u", oldBoxNum), box_lookup.at(boxUniqueId));
+				boxes.emplace_back(cell);
 			}
 		}
-		else
-			log_error("Line %u: cannot interpret first character '%c'!\n", line_count, c);
+		else if (c == 'a' || c == 'i' || c == 'o' || c == 's') {
+			uint32_t dataSize = parse_xaiger_literal(f);
+			f.ignore(dataSize);
+			log_debug("ignoring '%c'\n", c);
+		}
+		else {
+			break;
+		}
 	}
 
 	post_process();
@@ -487,13 +508,15 @@ void AigerReader::parse_aiger_ascii()
 	unsigned l1, l2, l3;
 
 	// Parse inputs
+	int digits = ceil(log10(I));
 	for (unsigned i = 1; i <= I; ++i, ++line_count) {
 		if (!(f >> l1))
 			log_error("Line %u cannot be interpreted as an input!\n", line_count);
 		log_debug2("%d is an input\n", l1);
 		log_assert(!(l1 & 1)); // Inputs can't be inverted
-		RTLIL::Wire *wire = createWireIfNotExists(module, l1);
+		RTLIL::Wire *wire = module->addWire(stringf("$i%0*d", digits, l1 >> 1));
 		wire->port_input = true;
+		module->connect(createWireIfNotExists(module, l1), wire);
 		inputs.push_back(wire);
 	}
 
@@ -507,12 +530,14 @@ void AigerReader::parse_aiger_ascii()
 		clk_wire->port_input = true;
 		clk_wire->port_output = false;
 	}
+	digits = ceil(log10(L));
 	for (unsigned i = 0; i < L; ++i, ++line_count) {
 		if (!(f >> l1 >> l2))
 			log_error("Line %u cannot be interpreted as a latch!\n", line_count);
 		log_debug2("%d %d is a latch\n", l1, l2);
 		log_assert(!(l1 & 1));
-		RTLIL::Wire *q_wire = createWireIfNotExists(module, l1);
+		RTLIL::Wire *q_wire = module->addWire(stringf("$l%0*d", digits, l1 >> 1));
+		module->connect(createWireIfNotExists(module, l1), q_wire);
 		RTLIL::Wire *d_wire = createWireIfNotExists(module, l2);
 
 		if (clk_wire)
@@ -550,7 +575,7 @@ void AigerReader::parse_aiger_ascii()
 		log_debug2("%d is an output\n", l1);
 		const unsigned variable = l1 >> 1;
 		const bool invert = l1 & 1;
-		RTLIL::IdString wire_name(stringf("\\__%d%s__", variable, invert ? "b" : "")); // FIXME: is "b" the right suffix?
+		RTLIL::IdString wire_name(stringf("$%d%s", variable, invert ? "b" : "")); // FIXME: is "b" the right suffix?
 		RTLIL::Wire *wire = module->wire(wire_name);
 		if (!wire)
 			wire = createWireIfNotExists(module, l1);
@@ -596,7 +621,7 @@ void AigerReader::parse_aiger_ascii()
 		RTLIL::Wire *o_wire = createWireIfNotExists(module, l1);
 		RTLIL::Wire *i1_wire = createWireIfNotExists(module, l2);
 		RTLIL::Wire *i2_wire = createWireIfNotExists(module, l3);
-		module->addAndGate(o_wire->name.str() + "$and", i1_wire, i2_wire, o_wire);
+		module->addAndGate("$and" + o_wire->name.str(), i1_wire, i2_wire, o_wire);
 	}
 	std::getline(f, line); // Ignore up to start of next line
 }
@@ -616,11 +641,12 @@ void AigerReader::parse_aiger_binary()
 	std::string line;
 
 	// Parse inputs
+	int digits = ceil(log10(I));
 	for (unsigned i = 1; i <= I; ++i) {
 		log_debug2("%d is an input\n", i);
-		RTLIL::Wire *wire = createWireIfNotExists(module, i << 1);
+		RTLIL::Wire *wire = module->addWire(stringf("$i%0*d", digits, i));
 		wire->port_input = true;
-		log_assert(!wire->port_output);
+		module->connect(createWireIfNotExists(module, i << 1), wire);
 		inputs.push_back(wire);
 	}
 
@@ -634,12 +660,14 @@ void AigerReader::parse_aiger_binary()
 		clk_wire->port_input = true;
 		clk_wire->port_output = false;
 	}
+	digits = ceil(log10(L));
 	l1 = (I+1) * 2;
 	for (unsigned i = 0; i < L; ++i, ++line_count, l1 += 2) {
 		if (!(f >> l2))
 			log_error("Line %u cannot be interpreted as a latch!\n", line_count);
 		log_debug("%d %d is a latch\n", l1, l2);
-		RTLIL::Wire *q_wire = createWireIfNotExists(module, l1);
+		RTLIL::Wire *q_wire = module->addWire(stringf("$l%0*d", digits, l1 >> 1));
+		module->connect(createWireIfNotExists(module, l1), q_wire);
 		RTLIL::Wire *d_wire = createWireIfNotExists(module, l2);
 
 		if (clk_wire)
@@ -670,23 +698,15 @@ void AigerReader::parse_aiger_binary()
 	}
 
 	// Parse outputs
+	digits = ceil(log10(O));
 	for (unsigned i = 0; i < O; ++i, ++line_count) {
 		if (!(f >> l1))
 			log_error("Line %u cannot be interpreted as an output!\n", line_count);
 
 		log_debug2("%d is an output\n", l1);
-		const unsigned variable = l1 >> 1;
-		const bool invert = l1 & 1;
-		RTLIL::IdString wire_name(stringf("\\__%d%s__", variable, invert ? "b" : "")); // FIXME: is "_b" the right suffix?
-		RTLIL::Wire *wire = module->wire(wire_name);
-		if (!wire)
-			wire = createWireIfNotExists(module, l1);
-		else if (wire->port_input || wire->port_output) {
-			RTLIL::Wire *new_wire = module->addWire(NEW_ID);
-			module->connect(new_wire, wire);
-			wire = new_wire;
-		}
+		RTLIL::Wire *wire = module->addWire(stringf("$o%0*d", digits, i));
 		wire->port_output = true;
+		module->connect(wire, createWireIfNotExists(module, l1));
 		outputs.push_back(wire);
 	}
 	std::getline(f, line); // Ignore up to start of next line
@@ -727,62 +747,43 @@ void AigerReader::parse_aiger_binary()
 		RTLIL::Wire *o_wire = createWireIfNotExists(module, l1);
 		RTLIL::Wire *i1_wire = createWireIfNotExists(module, l2);
 		RTLIL::Wire *i2_wire = createWireIfNotExists(module, l3);
-		module->addAndGate(o_wire->name.str() + "$and", i1_wire, i2_wire, o_wire);
+		module->addAndGate("$and" + o_wire->name.str(), i1_wire, i2_wire, o_wire);
 	}
 }
 
 void AigerReader::post_process()
 {
-	pool<IdString> seen_boxes;
-	unsigned ci_count = 0, co_count = 0;
+	dict<IdString, std::vector<IdString>> box_ports;
+	unsigned ci_count = 0, co_count = 0, flop_count = 0;
 	for (auto cell : boxes) {
 		RTLIL::Module* box_module = design->module(cell->type);
 		log_assert(box_module);
 
-		if (seen_boxes.insert(cell->type).second) {
-			auto it = box_module->attributes.find("\\abc9_carry");
-			if (it != box_module->attributes.end()) {
-				RTLIL::Wire *carry_in = nullptr, *carry_out = nullptr;
-				auto carry_in_out = it->second.decode_string();
-				auto pos = carry_in_out.find(',');
-				if (pos == std::string::npos)
-					log_error("'abc9_carry' attribute on module '%s' does not contain ','.\n", log_id(cell->type));
-				auto carry_in_name = RTLIL::escape_id(carry_in_out.substr(0, pos));
-				carry_in = box_module->wire(carry_in_name);
-				if (!carry_in || !carry_in->port_input)
-					log_error("'abc9_carry' on module '%s' contains '%s' which does not exist or is not an input port.\n", log_id(cell->type), carry_in_name.c_str());
-
-				auto carry_out_name = RTLIL::escape_id(carry_in_out.substr(pos+1));
-				carry_out = box_module->wire(carry_out_name);
-				if (!carry_out || !carry_out->port_output)
-					log_error("'abc9_carry' on module '%s' contains '%s' which does not exist or is not an output port.\n", log_id(cell->type), carry_out_name.c_str());
-
-				auto &ports = box_module->ports;
-				for (auto jt = ports.begin(); jt != ports.end(); ) {
-					RTLIL::Wire* w = box_module->wire(*jt);
-					log_assert(w);
-					if (w == carry_in || w == carry_out) {
-						jt = ports.erase(jt);
-						continue;
-					}
-					if (w->port_id > carry_in->port_id)
-						--w->port_id;
-					if (w->port_id > carry_out->port_id)
-						--w->port_id;
-					log_assert(w->port_input || w->port_output);
-					log_assert(ports[w->port_id-1] == w->name);
-					++jt;
+		auto r = box_ports.insert(cell->type);
+		if (r.second) {
+			// Make carry in the last PI, and carry out the last PO
+			//   since ABC requires it this way
+			IdString carry_in, carry_out;
+			for (const auto &port_name : box_module->ports) {
+				auto w = box_module->wire(port_name);
+				log_assert(w);
+				if (w->get_bool_attribute("\\abc9_carry")) {
+					if (w->port_input)
+						carry_in = port_name;
+					if (w->port_output)
+						carry_out = port_name;
 				}
-				ports.push_back(carry_in->name);
-				carry_in->port_id = ports.size();
-				ports.push_back(carry_out->name);
-				carry_out->port_id = ports.size();
+				else
+					r.first->second.push_back(port_name);
+			}
+			if (carry_in != IdString()) {
+				log_assert(carry_out != IdString());
+				r.first->second.push_back(carry_in);
+				r.first->second.push_back(carry_out);
 			}
 		}
 
-		// NB: Assume box_module->ports are sorted alphabetically
-		//     (as RTLIL::Module::fixup_ports() would do)
-		for (auto port_name : box_module->ports) {
+		for (auto port_name : box_ports.at(cell->type)) {
 			RTLIL::Wire* port = box_module->wire(port_name);
 			log_assert(port);
 			RTLIL::SigSpec rhs;
@@ -804,9 +805,32 @@ void AigerReader::post_process()
 				}
 				rhs.append(wire);
 			}
-
 			cell->setPort(port_name, rhs);
 		}
+
+		if (box_module->attributes.count("\\abc9_flop")) {
+			log_assert(co_count < outputs.size());
+			Wire *wire = outputs[co_count++];
+			log_assert(wire);
+			log_assert(wire->port_output);
+			wire->port_output = false;
+
+			RTLIL::Wire *d = outputs[outputs.size() - flopNum + flop_count];
+			log_assert(d);
+			log_assert(d->port_output);
+			d->port_output = false;
+
+			RTLIL::Wire *q = inputs[piNum - flopNum + flop_count];
+			log_assert(q);
+			log_assert(q->port_input);
+			q->port_input = false;
+
+			auto ff = module->addCell(NEW_ID, "$__ABC9_FF_");
+			ff->setPort("\\D", d);
+			ff->setPort("\\Q", q);
+			flop_count++;
+			continue;
+		}
 	}
 
 	dict<RTLIL::IdString, int> wideports_cache;
@@ -868,16 +892,7 @@ void AigerReader::post_process()
 					// simply connect the latter to the former
 					RTLIL::Wire* existing = module->wire(escaped_s);
 					if (!existing) {
-						if (escaped_s.ends_with("$inout.out")) {
-							wire->port_output = false;
-							RTLIL::Wire *in_wire = module->wire(escaped_s.substr(1, escaped_s.size()-11));
-							log_assert(in_wire);
-							log_assert(in_wire->port_input && !in_wire->port_output);
-							in_wire->port_output = true;
-							module->connect(in_wire, wire);
-						}
-						else
-							module->rename(wire, escaped_s);
+						module->rename(wire, escaped_s);
 					}
 					else {
 						wire->port_output = false;
@@ -889,19 +904,9 @@ void AigerReader::post_process()
 					std::string indexed_name = stringf("%s[%d]", escaped_s.c_str(), index);
 					RTLIL::Wire* existing = module->wire(indexed_name);
 					if (!existing) {
-						if (escaped_s.ends_with("$inout.out")) {
-							wire->port_output = false;
-							RTLIL::Wire *in_wire = module->wire(stringf("%s[%d]", escaped_s.substr(1, escaped_s.size()-11).c_str(), index));
-							log_assert(in_wire);
-							log_assert(in_wire->port_input && !in_wire->port_output);
-							in_wire->port_output = true;
-							module->connect(in_wire, wire);
-						}
-						else {
-							module->rename(wire, indexed_name);
-							if (wideports)
-								wideports_cache[escaped_s] = std::max(wideports_cache[escaped_s], index);
-						}
+						module->rename(wire, indexed_name);
+						if (wideports)
+							wideports_cache[escaped_s] = std::max(wideports_cache[escaped_s], index);
 					}
 					else {
 						module->connect(wire, existing);
@@ -909,9 +914,13 @@ void AigerReader::post_process()
 					}
 				}
 				log_debug(" -> %s\n", log_id(wire));
+				int init;
+				mf >> init;
+				if (init < 2)
+					wire->attributes["\\init"] = init;
 			}
 			else if (type == "box") {
-				RTLIL::Cell* cell = module->cell(stringf("$__box%d__", variable));
+				RTLIL::Cell* cell = module->cell(stringf("$box%d", variable));
 				if (cell) { // ABC could have optimised this box away
 					module->rename(cell, escaped_s);
 					for (const auto &i : cell->connections()) {
@@ -968,15 +977,10 @@ void AigerReader::post_process()
 			if (other_wire) {
 				other_wire->port_input = false;
 				other_wire->port_output = false;
-			}
-			if (wire->port_input) {
-				if (other_wire)
+				if (wire->port_input)
 					module->connect(other_wire, SigSpec(wire, i));
-			}
-			else {
-								  // Since we skip POs that are connected to Sx,
-								  // re-connect them here
-				module->connect(SigSpec(wire, i), other_wire ? other_wire : SigSpec(RTLIL::Sx));
+				else
+					module->connect(SigSpec(wire, i), other_wire);
 			}
 		}
 	}
@@ -997,9 +1001,9 @@ void AigerReader::post_process()
 		if (cell->type != "$lut") continue;
 		auto y_port = cell->getPort("\\Y").as_bit();
 		if (y_port.wire->width == 1)
-			module->rename(cell, stringf("%s$lut", y_port.wire->name.c_str()));
+			module->rename(cell, stringf("$lut%s", y_port.wire->name.c_str()));
 		else
-			module->rename(cell, stringf("%s[%d]$lut", y_port.wire->name.c_str(), y_port.offset));
+			module->rename(cell, stringf("$lut%s[%d]", y_port.wire->name.c_str(), y_port.offset));
 	}
 }
 
@@ -1032,7 +1036,7 @@ struct AigerFrontend : public Frontend {
 	{
 		log_header(design, "Executing AIGER frontend.\n");
 
-		RTLIL::IdString clk_name = "\\clk";
+		RTLIL::IdString clk_name;
 		RTLIL::IdString module_name;
 		std::string map_filename;
 		bool wideports = false;
diff --git a/frontends/aiger/aigerparse.h b/frontends/aiger/aigerparse.h
index 583c9d0f9..722f1e472 100644
--- a/frontends/aiger/aigerparse.h
+++ b/frontends/aiger/aigerparse.h
@@ -33,6 +33,7 @@ struct AigerReader
     RTLIL::Module *module;
     std::string map_filename;
     bool wideports;
+    const int aiger_autoidx;
 
     unsigned M, I, L, O, A;
     unsigned B, C, J, F; // Optional in AIGER 1.9
@@ -47,10 +48,12 @@ struct AigerReader
 
     AigerReader(RTLIL::Design *design, std::istream &f, RTLIL::IdString module_name, RTLIL::IdString clk_name, std::string map_filename, bool wideports);
     void parse_aiger();
-    void parse_xaiger(const dict<int,IdString> &box_lookup);
+    void parse_xaiger();
     void parse_aiger_ascii();
     void parse_aiger_binary();
     void post_process();
+
+    RTLIL::Wire* createWireIfNotExists(RTLIL::Module *module, unsigned literal);
 };
 
 YOSYS_NAMESPACE_END
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 44fd32cdc..b94a8d710 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -1198,6 +1198,14 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 		varbuf = new AstNode(AST_LOCALPARAM, varbuf);
 		varbuf->str = init_ast->children[0]->str;
 
+		auto resolved = current_scope.at(init_ast->children[0]->str);
+		if (resolved->range_valid) {
+			varbuf->range_left = resolved->range_left;
+			varbuf->range_right = resolved->range_right;
+			varbuf->range_swapped = resolved->range_swapped;
+			varbuf->range_valid = resolved->range_valid;
+		}
+
 		AstNode *backup_scope_varbuf = current_scope[varbuf->str];
 		current_scope[varbuf->str] = varbuf;
 
@@ -2998,6 +3006,14 @@ void AstNode::expand_genblock(std::string index_var, std::string prefix, std::ma
 			current_ast_mod->children.push_back(p);
 			str = p->str;
 			id2ast = p;
+
+			auto resolved = current_scope.at(index_var);
+			if (resolved->range_valid) {
+				p->range_left = resolved->range_left;
+				p->range_right = resolved->range_right;
+				p->range_swapped = resolved->range_swapped;
+				p->range_valid = resolved->range_valid;
+			}
 		}
 	}
 
diff --git a/frontends/ilang/ilang_parser.y b/frontends/ilang/ilang_parser.y
index b4b9693da..4e0b62edd 100644
--- a/frontends/ilang/ilang_parser.y
+++ b/frontends/ilang/ilang_parser.y
@@ -430,10 +430,14 @@ sigspec:
 		free($1);
 	} |
 	sigspec '[' TOK_INT ']' {
+		if ($3 >= $1->size() || $3 < 0)
+			rtlil_frontend_ilang_yyerror("bit index out of range");
 		$$ = new RTLIL::SigSpec($1->extract($3));
 		delete $1;
 	} |
 	sigspec '[' TOK_INT ':' TOK_INT ']' {
+		if ($3 >= $1->size() || $3 < 0 || $3 < $5)
+			rtlil_frontend_ilang_yyerror("invalid slice");
 		$$ = new RTLIL::SigSpec($1->extract($5, $3 - $5 + 1));
 		delete $1;
 	} |
diff --git a/frontends/verific/README b/frontends/verific/README
index 89584f2e8..c37d76343 100644
--- a/frontends/verific/README
+++ b/frontends/verific/README
@@ -1,7 +1,11 @@
 
-
 This directory contains Verific bindings for Yosys.
-See http://www.verific.com/ for details.
+
+Use Symbiotic EDA Suite if you need Yosys+Verifc.
+https://www.symbioticeda.com/seda-suite
+
+Contact office@symbioticeda.com for free evaluation
+binaries of Symbiotic EDA Suite.
 
 
 Verific Features that should be enabled in your Verific library
diff --git a/frontends/verific/verific.cc b/frontends/verific/verific.cc
index 05c615768..5b684036f 100644
--- a/frontends/verific/verific.cc
+++ b/frontends/verific/verific.cc
@@ -130,7 +130,7 @@ RTLIL::SigBit VerificImporter::net_map_at(Net *net)
 
 bool is_blackbox(Netlist *nl)
 {
-	if (nl->IsBlackBox())
+	if (nl->IsBlackBox() || nl->IsEmptyBox())
 		return true;
 
 	const char *attr = nl->GetAttValue("blackbox");
@@ -784,15 +784,15 @@ void VerificImporter::merge_past_ffs(pool<RTLIL::Cell*> &candidates)
 		merge_past_ffs_clock(it.second, it.first.first, it.first.second);
 }
 
-void VerificImporter::import_netlist(RTLIL::Design *design, Netlist *nl, std::set<Netlist*> &nl_todo)
+void VerificImporter::import_netlist(RTLIL::Design *design, Netlist *nl, std::set<Netlist*> &nl_todo, bool norename)
 {
 	std::string netlist_name = nl->GetAtt(" \\top") ? nl->CellBaseName() : nl->Owner()->Name();
 	std::string module_name = netlist_name;
 
-	if (nl->IsOperator()) {
+	if (nl->IsOperator() || nl->IsPrimitive()) {
 		module_name = "$verific$" + module_name;
 	} else {
-		if (*nl->Name()) {
+		if (!norename && *nl->Name()) {
 			module_name += "(";
 			module_name += nl->Name();
 			module_name += ")";
@@ -1409,7 +1409,7 @@ void VerificImporter::import_netlist(RTLIL::Design *design, Netlist *nl, std::se
 
 		std::string inst_type = inst->View()->Owner()->Name();
 
-		if (inst->View()->IsOperator()) {
+		if (inst->View()->IsOperator() || inst->View()->IsPrimitive()) {
 			inst_type = "$verific$" + inst_type;
 		} else {
 			if (*inst->View()->Name()) {
@@ -1899,7 +1899,7 @@ void verific_import(Design *design, const std::map<std::string,std::string> &par
 		Netlist *nl = *nl_todo.begin();
 		if (nl_done.count(nl) == 0) {
 			VerificImporter importer(false, false, false, false, false, false, false);
-			importer.import_netlist(design, nl, nl_todo);
+			importer.import_netlist(design, nl, nl_todo, nl->Owner()->Name() == top);
 		}
 		nl_todo.erase(nl);
 		nl_done.insert(nl);
@@ -2065,7 +2065,12 @@ struct VerificPass : public Pass {
 		log("  -d <dump_file>\n");
 		log("    Dump the Verific netlist as a verilog file.\n");
 		log("\n");
-		log("Visit http://verific.com/ for more information on Verific.\n");
+		log("\n");
+		log("Use Symbiotic EDA Suite if you need Yosys+Verifc.\n");
+		log("https://www.symbioticeda.com/seda-suite\n");
+		log("\n");
+		log("Contact office@symbioticeda.com for free evaluation\n");
+		log("binaries of Symbiotic EDA Suite.\n");
 		log("\n");
 	}
 #ifdef YOSYS_ENABLE_VERIFIC
@@ -2074,7 +2079,13 @@ struct VerificPass : public Pass {
 		static bool set_verific_global_flags = true;
 
 		if (check_noverific_env())
-			log_cmd_error("This version of Yosys is built without Verific support.\n");
+			log_cmd_error("This version of Yosys is built without Verific support.\n"
+					"\n"
+					"Use Symbiotic EDA Suite if you need Yosys+Verifc.\n"
+					"https://www.symbioticeda.com/seda-suite\n"
+					"\n"
+					"Contact office@symbioticeda.com for free evaluation\n"
+					"binaries of Symbiotic EDA Suite.\n");
 
 		log_header(design, "Executing VERIFIC (loading SystemVerilog and VHDL designs using Verific).\n");
 
@@ -2373,6 +2384,8 @@ struct VerificPass : public Pass {
 			if (argidx > GetSize(args) && args[argidx].compare(0, 1, "-") == 0)
 				cmd_error(args, argidx, "unknown option");
 
+			std::set<std::string> top_mod_names;
+
 			if (mode_all)
 			{
 				log("Running hier_tree::ElaborateAll().\n");
@@ -2401,6 +2414,7 @@ struct VerificPass : public Pass {
 				for (; argidx < GetSize(args); argidx++)
 				{
 					const char *name = args[argidx].c_str();
+					top_mod_names.insert(name);
 					VeriLibrary* veri_lib = veri_file::GetLibrary(work.c_str(), 1);
 
 					if (veri_lib) {
@@ -2466,7 +2480,7 @@ struct VerificPass : public Pass {
 				if (nl_done.count(nl) == 0) {
 					VerificImporter importer(mode_gates, mode_keep, mode_nosva,
 							mode_names, mode_verific, mode_autocover, mode_fullinit);
-					importer.import_netlist(design, nl, nl_todo);
+					importer.import_netlist(design, nl, nl_todo, top_mod_names.count(nl->Owner()->Name()));
 				}
 				nl_todo.erase(nl);
 				nl_done.insert(nl);
@@ -2490,7 +2504,13 @@ struct VerificPass : public Pass {
 	}
 #else /* YOSYS_ENABLE_VERIFIC */
 	void execute(std::vector<std::string>, RTLIL::Design *) YS_OVERRIDE {
-		log_cmd_error("This version of Yosys is built without Verific support.\n");
+		log_cmd_error("This version of Yosys is built without Verific support.\n"
+				"\n"
+				"Use Symbiotic EDA Suite if you need Yosys+Verifc.\n"
+				"https://www.symbioticeda.com/seda-suite\n"
+				"\n"
+				"Contact office@symbioticeda.com for free evaluation\n"
+				"binaries of Symbiotic EDA Suite.\n");
 	}
 #endif
 } VerificPass;
diff --git a/frontends/verific/verific.h b/frontends/verific/verific.h
index 5cbd78f7b..2ccfcd42c 100644
--- a/frontends/verific/verific.h
+++ b/frontends/verific/verific.h
@@ -93,7 +93,7 @@ struct VerificImporter
 	void merge_past_ffs_clock(pool<RTLIL::Cell*> &candidates, SigBit clock, bool clock_pol);
 	void merge_past_ffs(pool<RTLIL::Cell*> &candidates);
 
-	void import_netlist(RTLIL::Design *design, Verific::Netlist *nl, std::set<Verific::Netlist*> &nl_todo);
+	void import_netlist(RTLIL::Design *design, Verific::Netlist *nl, std::set<Verific::Netlist*> &nl_todo, bool norename = false);
 };
 
 void verific_import_sva_assert(VerificImporter *importer, Verific::Instance *inst);
diff --git a/frontends/verific/verificsva.cc b/frontends/verific/verificsva.cc
index 909e9b4f1..49c0c40ac 100644
--- a/frontends/verific/verificsva.cc
+++ b/frontends/verific/verificsva.cc
@@ -36,6 +36,8 @@
 // basic_property:
 //   sequence
 //   not basic_property
+//   nexttime basic_property
+//   nexttime[N] basic_property
 //   sequence #-# basic_property
 //   sequence #=# basic_property
 //   basic_property or basic_property           (cover only)
@@ -1264,6 +1266,26 @@ struct VerificSvaImporter
 			return node;
 		}
 
+		if (inst->Type() == PRIM_SVA_NEXTTIME || inst->Type() == PRIM_SVA_S_NEXTTIME)
+		{
+			const char *sva_low_s = inst->GetAttValue("sva:low");
+			const char *sva_high_s = inst->GetAttValue("sva:high");
+
+			int sva_low = atoi(sva_low_s);
+			int sva_high = atoi(sva_high_s);
+			log_assert(sva_low == sva_high);
+
+			int node = start_node;
+
+			for (int i = 0; i < sva_low; i++) {
+				int next_node = fsm.createNode();
+				fsm.createEdge(node, next_node);
+				node = next_node;
+			}
+
+			return parse_sequence(fsm, node, inst->GetInput());
+		}
+
 		if (inst->Type() == PRIM_SVA_SEQ_CONCAT)
 		{
 			const char *sva_low_s = inst->GetAttValue("sva:low");
@@ -1590,15 +1612,25 @@ struct VerificSvaImporter
 			Instance *consequent_inst = net_to_ast_driver(consequent_net);
 
 			if (consequent_inst && (consequent_inst->Type() == PRIM_SVA_UNTIL || consequent_inst->Type() == PRIM_SVA_S_UNTIL ||
-					consequent_inst->Type() == PRIM_SVA_UNTIL_WITH || consequent_inst->Type() == PRIM_SVA_S_UNTIL_WITH))
+					consequent_inst->Type() == PRIM_SVA_UNTIL_WITH || consequent_inst->Type() == PRIM_SVA_S_UNTIL_WITH ||
+					consequent_inst->Type() == PRIM_SVA_ALWAYS || consequent_inst->Type() == PRIM_SVA_S_ALWAYS))
 			{
 				bool until_with = consequent_inst->Type() == PRIM_SVA_UNTIL_WITH || consequent_inst->Type() == PRIM_SVA_S_UNTIL_WITH;
 
-				Net *until_net = consequent_inst->GetInput2();
-				consequent_net = consequent_inst->GetInput1();
-				consequent_inst = net_to_ast_driver(consequent_net);
+				Net *until_net = nullptr;
+				if (consequent_inst->Type() == PRIM_SVA_ALWAYS || consequent_inst->Type() == PRIM_SVA_S_ALWAYS)
+				{
+					consequent_net = consequent_inst->GetInput();
+					consequent_inst = net_to_ast_driver(consequent_net);
+				}
+				else
+				{
+					until_net = consequent_inst->GetInput2();
+					consequent_net = consequent_inst->GetInput1();
+					consequent_inst = net_to_ast_driver(consequent_net);
+				}
 
-				SigBit until_sig = parse_expression(until_net);
+				SigBit until_sig = until_net ? parse_expression(until_net) : RTLIL::S0;
 				SigBit not_until_sig = module->Not(NEW_ID, until_sig);
 				antecedent_fsm.createEdge(node, node, not_until_sig);
 
diff --git a/frontends/verilog/preproc.cc b/frontends/verilog/preproc.cc
index 7e107dc26..161253a99 100644
--- a/frontends/verilog/preproc.cc
+++ b/frontends/verilog/preproc.cc
@@ -28,7 +28,7 @@
  *
  *  Ad-hoc implementation of a Verilog preprocessor. The directives `define,
  *  `include, `ifdef, `ifndef, `else and `endif are handled here. All other
- *  directives are handled by the lexer (see lexer.l).
+ *  directives are handled by the lexer (see verilog_lexer.l).
  *
  */
 
diff --git a/frontends/verilog/verilog_lexer.l b/frontends/verilog/verilog_lexer.l
index 4acfb414d..ca23df3e8 100644
--- a/frontends/verilog/verilog_lexer.l
+++ b/frontends/verilog/verilog_lexer.l
@@ -28,7 +28,7 @@
  *
  *  A simple lexer for Verilog code. Non-preprocessor compiler directives are
  *  handled here. The preprocessor stuff is handled in preproc.cc. Everything
- *  else is left to the bison parser (see parser.y).
+ *  else is left to the bison parser (see verilog_parser.y).
  *
  */
 
@@ -188,9 +188,9 @@ YOSYS_NAMESPACE_END
 "unique0"      { SV_KEYWORD(TOK_UNIQUE); }
 "priority"     { SV_KEYWORD(TOK_PRIORITY); }
 
-"always_comb"  { SV_KEYWORD(TOK_ALWAYS); }
-"always_ff"    { SV_KEYWORD(TOK_ALWAYS); }
-"always_latch" { SV_KEYWORD(TOK_ALWAYS); }
+"always_comb"  { SV_KEYWORD(TOK_ALWAYS_COMB); }
+"always_ff"    { SV_KEYWORD(TOK_ALWAYS_FF); }
+"always_latch" { SV_KEYWORD(TOK_ALWAYS_LATCH); }
 
  /* use special token for labels on assert, assume, cover, and restrict because it's insanley complex
     to fix parsing of cells otherwise. (the current cell parser forces a reduce very early to update some
diff --git a/frontends/verilog/verilog_parser.y b/frontends/verilog/verilog_parser.y
index 77f6d2051..a30935e0a 100644
--- a/frontends/verilog/verilog_parser.y
+++ b/frontends/verilog/verilog_parser.y
@@ -141,6 +141,7 @@ struct specify_rise_fall {
 %token TOK_INTERFACE TOK_ENDINTERFACE TOK_MODPORT TOK_VAR
 %token TOK_INPUT TOK_OUTPUT TOK_INOUT TOK_WIRE TOK_WAND TOK_WOR TOK_REG TOK_LOGIC
 %token TOK_INTEGER TOK_SIGNED TOK_ASSIGN TOK_ALWAYS TOK_INITIAL
+%token TOK_ALWAYS_FF TOK_ALWAYS_COMB TOK_ALWAYS_LATCH
 %token TOK_BEGIN TOK_END TOK_IF TOK_ELSE TOK_FOR TOK_WHILE TOK_REPEAT
 %token TOK_DPI_FUNCTION TOK_POSEDGE TOK_NEGEDGE TOK_OR TOK_AUTOMATIC
 %token TOK_CASE TOK_CASEX TOK_CASEZ TOK_ENDCASE TOK_DEFAULT
@@ -156,7 +157,7 @@ struct specify_rise_fall {
 %type <ast> range range_or_multirange  non_opt_range non_opt_multirange range_or_signed_int
 %type <ast> wire_type expr basic_expr concat_list rvalue lvalue lvalue_concat_list
 %type <string> opt_label opt_sva_label tok_prim_wrapper hierarchical_id hierarchical_type_id
-%type <boolean> opt_signed opt_property unique_case_attr
+%type <boolean> opt_signed opt_property unique_case_attr always_comb_or_latch always_or_always_ff
 %type <al> attr case_attr
 
 %type <specify_target_ptr> specify_target
@@ -1581,10 +1582,28 @@ cell_port:
 		free_attr($1);
 	};
 
+always_comb_or_latch:
+	TOK_ALWAYS_COMB {
+		$$ = false;
+	} |
+	TOK_ALWAYS_LATCH {
+		$$ = true;
+	};
+
+always_or_always_ff:
+	TOK_ALWAYS {
+		$$ = false;
+	} |
+	TOK_ALWAYS_FF {
+		$$ = true;
+	};
+
 always_stmt:
-	attr TOK_ALWAYS {
+	attr always_or_always_ff {
 		AstNode *node = new AstNode(AST_ALWAYS);
 		append_attr(node, $1);
+		if ($2)
+			node->attributes[ID(always_ff)] = AstNode::mkconst_int(1, false);
 		ast_stack.back()->children.push_back(node);
 		ast_stack.push_back(node);
 	} always_cond {
@@ -1595,6 +1614,22 @@ always_stmt:
 		ast_stack.pop_back();
 		ast_stack.pop_back();
 	} |
+	attr always_comb_or_latch {
+		AstNode *node = new AstNode(AST_ALWAYS);
+		append_attr(node, $1);
+		if ($2)
+			node->attributes[ID(always_latch)] = AstNode::mkconst_int(1, false);
+		else
+			node->attributes[ID(always_comb)] = AstNode::mkconst_int(1, false);
+		ast_stack.back()->children.push_back(node);
+		ast_stack.push_back(node);
+		AstNode *block = new AstNode(AST_BLOCK);
+		ast_stack.back()->children.push_back(block);
+		ast_stack.push_back(block);
+	} behavioral_stmt {
+		ast_stack.pop_back();
+		ast_stack.pop_back();
+	} |
 	attr TOK_INITIAL {
 		AstNode *node = new AstNode(AST_INITIAL);
 		append_attr(node, $1);
@@ -2207,7 +2242,7 @@ gen_stmt:
 		ast_stack.back()->children.push_back(node);
 		ast_stack.push_back(node);
 	} opt_arg_list ';'{
-		ast_stack.pop_back();		
+		ast_stack.pop_back();
 	};
 
 gen_stmt_block:
@@ -2378,19 +2413,19 @@ basic_expr:
 		append_attr($$, $2);
 	} |
 	basic_expr OP_SHL attr basic_expr {
-		$$ = new AstNode(AST_SHIFT_LEFT, $1, $4);
+		$$ = new AstNode(AST_SHIFT_LEFT, $1, new AstNode(AST_TO_UNSIGNED, $4));
 		append_attr($$, $3);
 	} |
 	basic_expr OP_SHR attr basic_expr {
-		$$ = new AstNode(AST_SHIFT_RIGHT, $1, $4);
+		$$ = new AstNode(AST_SHIFT_RIGHT, $1, new AstNode(AST_TO_UNSIGNED, $4));
 		append_attr($$, $3);
 	} |
 	basic_expr OP_SSHL attr basic_expr {
-		$$ = new AstNode(AST_SHIFT_SLEFT, $1, $4);
+		$$ = new AstNode(AST_SHIFT_SLEFT, $1, new AstNode(AST_TO_UNSIGNED, $4));
 		append_attr($$, $3);
 	} |
 	basic_expr OP_SSHR attr basic_expr {
-		$$ = new AstNode(AST_SHIFT_SRIGHT, $1, $4);
+		$$ = new AstNode(AST_SHIFT_SRIGHT, $1, new AstNode(AST_TO_UNSIGNED, $4));
 		append_attr($$, $3);
 	} |
 	basic_expr '<' attr basic_expr {