Merge remote-tracking branch 'origin/master' into xaig

21 files changed, 280 insertions, 129 deletions

diff --git a/.travis/build-and-test.sh b/.travis/build-and-test.sh
index 096dde64f..b8c35041d 100755
--- a/.travis/build-and-test.sh
+++ b/.travis/build-and-test.sh
@@ -36,6 +36,8 @@ echo
 
 ##########################################################################
 
+./yosys tests/simple/fiedler-cooley.v
+
 echo
 echo 'Testing...' && echo -en 'travis_fold:start:script.test\\r'
 echo
diff --git a/.travis/setup.sh b/.travis/setup.sh
index d689cd2bd..4af0b8ee9 100755
--- a/.travis/setup.sh
+++ b/.travis/setup.sh
@@ -6,48 +6,15 @@ source .travis/common.sh
 
 ##########################################################################
 
-# Fixing Travis's git clone
-echo
-echo 'Fixing git setup...' && echo -en 'travis_fold:start:before_install.git\\r'
-echo
-git fetch --unshallow && git fetch --tags
-
-# For pull requests, we get more info about the git source.
-if [ z"$TRAVIS_PULL_REQUEST_SLUG" != z ]; then
-	echo "- Fetching from pull request source"
-	git remote add source https://github.com/$TRAVIS_PULL_REQUEST_SLUG.git
-	git fetch source && git fetch --tags
-
-	echo "- Fetching the actual pull request"
-	git fetch origin pull/$TRAVIS_PULL_REQUEST/head:pull-$TRAVIS_PULL_REQUEST-head
-	git fetch origin pull/$TRAVIS_PULL_REQUEST/merge:pull-$TRAVIS_PULL_REQUEST-merge
-
-	git log -n 5 --graph pull-$TRAVIS_PULL_REQUEST-merge
-fi
-
-# For building branches we need to fix the "detached head" state.
-if [ z"$TRAVIS_BRANCH" != z ]; then
-	TRAVIS_COMMIT_ACTUAL=$(git log --pretty=format:'%H' -n 1)
-	echo "- Fixing detached head (current $TRAVIS_COMMIT_ACTUAL -> $TRAVIS_COMMIT)"
-	git remote -v
-	git branch -v
-	if [ x"$(git show-ref -s HEAD)" = x"$TRAVIS_COMMIT" ]; then
-		echo "Checked out at $TRAVIS_COMMIT"
-	else
-		if [ z"$TRAVIS_PULL_REQUEST_SLUG" != z ]; then
-			git fetch source $TRAVIS_COMMIT || echo "Unable to fetch $TRAVIS_COMMIT from source"
-		fi
-		git fetch origin $TRAVIS_COMMIT || echo "Unable to fetch $TRAVIS_COMMIT from origin"
-	fi
-	git branch -D $TRAVIS_BRANCH || true
-	git checkout $TRAVIS_COMMIT -b $TRAVIS_BRANCH
-	git branch -v
-fi
-
 # Output status information.
-git status
-git describe --tags
-git log -n 5 --graph
+(
+	set +e
+	set -x
+	git status
+	git branch -v
+	git log -n 5 --graph
+	git log --format=oneline -n 20 --graph
+)
 echo
 echo -en 'travis_fold:end:before_install.git\\r'
 echo
diff --git a/Makefile b/Makefile
index 0c9a831cc..c233b0a41 100644
--- a/Makefile
+++ b/Makefile
@@ -100,7 +100,7 @@ LDFLAGS += -rdynamic
 LDLIBS += -lrt
 endif
 
-YOSYS_VER := 0.8+$(shell cd $(YOSYS_SRC) && test -e .git && { git log --author=clifford@clifford.at --oneline 4d4665b.. | wc -l; })
+YOSYS_VER := 0.8+$(shell cd $(YOSYS_SRC) && test -e .git && { git log --author=clifford@clifford.at --oneline 4d4665b.. 2> /dev/null | wc -l; })
 GIT_REV := $(shell cd $(YOSYS_SRC) && git rev-parse --short HEAD 2> /dev/null || echo UNKNOWN)
 OBJS = kernel/version_$(GIT_REV).o
 
diff --git a/frontends/ast/genrtlil.cc b/frontends/ast/genrtlil.cc
index e66625228..2d591b29d 100644
--- a/frontends/ast/genrtlil.cc
+++ b/frontends/ast/genrtlil.cc
@@ -644,7 +644,7 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun
 				while (right_at_zero_ast->simplify(true, true, false, 1, -1, false, false)) { }
 				if (left_at_zero_ast->type != AST_CONSTANT || right_at_zero_ast->type != AST_CONSTANT)
 					log_file_error(filename, linenum, "Unsupported expression on dynamic range select on signal `%s'!\n", str.c_str());
-				this_width = left_at_zero_ast->integer - right_at_zero_ast->integer + 1;
+				this_width = abs(int(left_at_zero_ast->integer - right_at_zero_ast->integer)) + 1;
 				delete left_at_zero_ast;
 				delete right_at_zero_ast;
 			} else
@@ -792,7 +792,7 @@ void AstNode::detectSignWidthWorker(int &width_hint, bool &sign_hint, bool *foun
 	// everything should have been handled above -> print error if not.
 	default:
 		for (auto f : log_files)
-			current_ast->dumpAst(f, "verilog-ast> ");
+			current_ast_mod->dumpAst(f, "verilog-ast> ");
 		log_file_error(filename, linenum, "Don't know how to detect sign and width for %s node!\n", type2str(type).c_str());
 	}
 
@@ -1034,7 +1034,7 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 					while (right_at_zero_ast->simplify(true, true, false, 1, -1, false, false)) { }
 					if (left_at_zero_ast->type != AST_CONSTANT || right_at_zero_ast->type != AST_CONSTANT)
 						log_file_error(filename, linenum, "Unsupported expression on dynamic range select on signal `%s'!\n", str.c_str());
-					int width = left_at_zero_ast->integer - right_at_zero_ast->integer + 1;
+					int width = abs(int(left_at_zero_ast->integer - right_at_zero_ast->integer)) + 1;
 					AstNode *fake_ast = new AstNode(AST_NONE, clone(), children[0]->children.size() >= 2 ?
 							children[0]->children[1]->clone() : children[0]->children[0]->clone());
 					fake_ast->children[0]->delete_children();
@@ -1565,7 +1565,7 @@ RTLIL::SigSpec AstNode::genRTLIL(int width_hint, bool sign_hint)
 	// everything should have been handled above -> print error if not.
 	default:
 		for (auto f : log_files)
-			current_ast->dumpAst(f, "verilog-ast> ");
+			current_ast_mod->dumpAst(f, "verilog-ast> ");
 		type_name = type2str(type);
 		log_file_error(filename, linenum, "Don't know how to generate RTLIL code for %s node!\n", type_name.c_str());
 	}
diff --git a/frontends/ast/simplify.cc b/frontends/ast/simplify.cc
index 83714f897..46013544b 100644
--- a/frontends/ast/simplify.cc
+++ b/frontends/ast/simplify.cc
@@ -642,6 +642,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 	// (iterate by index as e.g. auto wires can add new children in the process)
 	for (size_t i = 0; i < children.size(); i++) {
 		bool did_something_here = true;
+		bool backup_flag_autowire = flag_autowire;
 		if ((type == AST_GENFOR || type == AST_FOR) && i >= 3)
 			break;
 		if ((type == AST_GENIF || type == AST_GENCASE) && i >= 1)
@@ -652,6 +653,8 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 			break;
 		if (type == AST_PREFIX && i >= 1)
 			break;
+		if (type == AST_DEFPARAM && i == 0)
+			flag_autowire = true;
 		while (did_something_here && i < children.size()) {
 			bool const_fold_here = const_fold, in_lvalue_here = in_lvalue;
 			int width_hint_here = width_hint;
@@ -686,6 +689,7 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 			children.erase(children.begin() + (i--));
 			did_something = true;
 		}
+		flag_autowire = backup_flag_autowire;
 	}
 	for (auto &attr : attributes) {
 		while (attr.second->simplify(true, false, false, stage, -1, false, true))
@@ -934,12 +938,15 @@ bool AstNode::simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage,
 			}
 		}
 		if (current_scope.count(str) == 0) {
-			// log_warning("Creating auto-wire `%s' in module `%s'.\n", str.c_str(), current_ast_mod->str.c_str());
-			AstNode *auto_wire = new AstNode(AST_AUTOWIRE);
-			auto_wire->str = str;
-			current_ast_mod->children.push_back(auto_wire);
-			current_scope[str] = auto_wire;
-			did_something = true;
+			if (flag_autowire) {
+				AstNode *auto_wire = new AstNode(AST_AUTOWIRE);
+				auto_wire->str = str;
+				current_ast_mod->children.push_back(auto_wire);
+				current_scope[str] = auto_wire;
+				did_something = true;
+			} else {
+				log_file_error(filename, linenum, "Identifier `%s' is implicitly declared and `default_nettype is set to none.\n", str.c_str());
+			}
 		}
 		if (id2ast != current_scope[str]) {
 			id2ast = current_scope[str];
@@ -1689,7 +1696,7 @@ skip_dynamic_range_lvalue_expansion:;
 				while (right_at_zero_ast->simplify(true, true, false, 1, -1, false, false)) { }
 				if (left_at_zero_ast->type != AST_CONSTANT || right_at_zero_ast->type != AST_CONSTANT)
 					log_file_error(filename, linenum, "Unsupported expression on dynamic range select on signal `%s'!\n", str.c_str());
-				int width = left_at_zero_ast->integer - right_at_zero_ast->integer + 1;
+				int width = abs(int(left_at_zero_ast->integer - right_at_zero_ast->integer)) + 1;
 
 				assign_data = new AstNode(AST_ASSIGN_LE, new AstNode(AST_IDENTIFIER),
 						new AstNode(AST_SHIFT_LEFT, children[1]->clone(), offset_ast->clone()));
@@ -1778,7 +1785,7 @@ skip_dynamic_range_lvalue_expansion:;
 
 			if (str == "\\$past")
 			{
-				if (width_hint <= 0)
+				if (width_hint < 0)
 					goto replace_fcall_later;
 
 				int num_steps = 1;
diff --git a/frontends/verific/verific.cc b/frontends/verific/verific.cc
index 94138cdd6..8ee951d20 100644
--- a/frontends/verific/verific.cc
+++ b/frontends/verific/verific.cc
@@ -1920,6 +1920,10 @@ struct VerificPass : public Pass {
 			// WARNING: instantiating unknown module 'XYZ' (VERI-1063)
 			Message::SetMessageType("VERI-1063", VERIFIC_ERROR);
 
+#ifndef DB_PRESERVE_INITIAL_VALUE
+#  warning Verific was built without DB_PRESERVE_INITIAL_VALUE.
+#endif
+
 			set_verific_global_flags = false;
 		}
 
diff --git a/kernel/driver.cc b/kernel/driver.cc
index 178641101..a0bb7e60a 100644
--- a/kernel/driver.cc
+++ b/kernel/driver.cc
@@ -179,6 +179,7 @@ int main(int argc, char **argv)
 {
 	std::string frontend_command = "auto";
 	std::string backend_command = "auto";
+	std::vector<std::string> vlog_defines;
 	std::vector<std::string> passes_commands;
 	std::vector<std::string> plugin_filenames;
 	std::string output_filename = "";
@@ -268,7 +269,10 @@ int main(int argc, char **argv)
 		printf("    -A\n");
 		printf("        will call abort() at the end of the script. for debugging\n");
 		printf("\n");
-		printf("    -D <header_id>[:<filename>]\n");
+		printf("    -D <macro>[=<value>]\n");
+		printf("        set the specified Verilog define (via \"read -define\")\n");
+		printf("\n");
+		printf("    -P <header_id>[:<filename>]\n");
 		printf("        dump the design when printing the specified log header to a file.\n");
 		printf("        yosys_dump_<header_id>.il is used as filename if none is specified.\n");
 		printf("        Use 'ALL' as <header_id> to dump at every header.\n");
@@ -307,7 +311,7 @@ int main(int argc, char **argv)
 	}
 
 	int opt;
-	while ((opt = getopt(argc, argv, "MXAQTVSm:f:Hh:b:o:p:l:L:qv:tds:c:W:w:e:D:E:")) != -1)
+	while ((opt = getopt(argc, argv, "MXAQTVSm:f:Hh:b:o:p:l:L:qv:tds:c:W:w:e:D:P:E:")) != -1)
 	{
 		switch (opt)
 		{
@@ -408,6 +412,9 @@ int main(int argc, char **argv)
 					std::regex_constants::egrep));
 			break;
 		case 'D':
+			vlog_defines.push_back(optarg);
+			break;
+		case 'P':
 			{
 				auto args = split_tokens(optarg, ":");
 				if (!args.empty() && args[0] == "ALL") {
@@ -473,6 +480,13 @@ int main(int argc, char **argv)
 		shell(yosys_design);
 	}
 
+	if (!vlog_defines.empty()) {
+		std::string vdef_cmd = "read -define";
+		for (auto vdef : vlog_defines)
+			vdef_cmd += " " + vdef;
+		run_pass(vdef_cmd);
+	}
+
 	while (optind < argc)
 		run_frontend(argv[optind++], frontend_command, output_filename == "-" ? &backend_command : NULL);
 
diff --git a/passes/hierarchy/hierarchy.cc b/passes/hierarchy/hierarchy.cc
index 0e28dbca2..2d8edebb5 100644
--- a/passes/hierarchy/hierarchy.cc
+++ b/passes/hierarchy/hierarchy.cc
@@ -140,6 +140,23 @@ void generate(RTLIL::Design *design, const std::vector<std::string> &celltypes,
 	}
 }
 
+// Return the "basic" type for an array item.
+std::string basic_cell_type(const std::string celltype, int pos[3] = nullptr) {
+	std::string basicType = celltype;
+	if (celltype.substr(0, 7) == "$array:") {
+		int pos_idx = celltype.find_first_of(':');
+		int pos_num = celltype.find_first_of(':', pos_idx + 1);
+		int pos_type = celltype.find_first_of(':', pos_num + 1);
+		basicType = celltype.substr(pos_type + 1);
+		if (pos != nullptr) {
+			pos[0] = pos_idx;
+			pos[1] = pos_num;
+			pos[2] = pos_type;
+		}
+	}
+	return basicType;
+}
+
 bool expand_module(RTLIL::Design *design, RTLIL::Module *module, bool flag_check, bool flag_simcheck, std::vector<std::string> &libdirs)
 {
 	bool did_something = false;
@@ -178,9 +195,11 @@ bool expand_module(RTLIL::Design *design, RTLIL::Module *module, bool flag_check
 		std::vector<RTLIL::SigSpec> connections_to_add_signal;
 
 		if (cell->type.substr(0, 7) == "$array:") {
-			int pos_idx = cell->type.str().find_first_of(':');
-			int pos_num = cell->type.str().find_first_of(':', pos_idx + 1);
-			int pos_type = cell->type.str().find_first_of(':', pos_num + 1);
+			int pos[3];
+			basic_cell_type(cell->type.str(), pos);
+			int pos_idx = pos[0];
+			int pos_num = pos[1];
+			int pos_type = pos[2];
 			int idx = atoi(cell->type.str().substr(pos_idx + 1, pos_num).c_str());
 			int num = atoi(cell->type.str().substr(pos_num + 1, pos_type).c_str());
 			array_cells[cell] = std::pair<int, int>(idx, num);
@@ -439,10 +458,7 @@ void hierarchy_worker(RTLIL::Design *design, std::set<RTLIL::Module*, IdString::
 	for (auto cell : mod->cells()) {
 		std::string celltype = cell->type.str();
 		if (celltype.substr(0, 7) == "$array:") {
-			int pos_idx = celltype.find_first_of(':');
-			int pos_num = celltype.find_first_of(':', pos_idx + 1);
-			int pos_type = celltype.find_first_of(':', pos_num + 1);
-			celltype = celltype.substr(pos_type + 1);
+			celltype = basic_cell_type(celltype);
 		}
 		if (design->module(celltype))
 			hierarchy_worker(design, used, design->module(celltype), indent+4);
@@ -502,9 +518,19 @@ int find_top_mod_score(Design *design, Module *module, dict<Module*, int> &db)
 	if (db.count(module) == 0) {
 		int score = 0;
 		db[module] = 0;
-		for (auto cell : module->cells())
-			if (design->module(cell->type))
-				score = max(score, find_top_mod_score(design, design->module(cell->type), db) + 1);
+		for (auto cell : module->cells()) {
+			std::string celltype = cell->type.str();
+			// Is this an array instance
+			if (celltype.substr(0, 7) == "$array:") {
+				celltype = basic_cell_type(celltype);
+			}
+			// Is this cell a module instance?
+			auto instModule = design->module(celltype);
+			// If there is no instance for this, issue a warning.
+			if (instModule != nullptr) {
+				score = max(score, find_top_mod_score(design, instModule, db) + 1);
+			}
+		}
 		db[module] = score;
 	}
 	return db.at(module);
diff --git a/passes/opt/wreduce.cc b/passes/opt/wreduce.cc
index 3aa916ec2..09983bc67 100644
--- a/passes/opt/wreduce.cc
+++ b/passes/opt/wreduce.cc
@@ -195,6 +195,13 @@ struct WreduceWorker
 		for (auto bit : sig_q)
 			work_queue_bits.insert(bit);
 
+		// Narrow ARST_VALUE parameter to new size.
+		if (cell->parameters.count("\\ARST_VALUE")) {
+			Const arst_value = cell->getParam("\\ARST_VALUE");
+			arst_value.bits.resize(GetSize(sig_q));
+			cell->setParam("\\ARST_VALUE", arst_value);
+		}
+
 		cell->setPort("\\D", sig_d);
 		cell->setPort("\\Q", sig_q);
 		cell->fixup_parameters();
diff --git a/passes/techmap/abc.cc b/passes/techmap/abc.cc
index d2d15a4a9..21b70f492 100644
--- a/passes/techmap/abc.cc
+++ b/passes/techmap/abc.cc
@@ -327,8 +327,26 @@ void extract_cell(RTLIL::Cell *cell, bool keepff)
 	}
 }
 
-std::string remap_name(RTLIL::IdString abc_name)
+std::string remap_name(RTLIL::IdString abc_name, RTLIL::Wire **orig_wire = nullptr)
 {
+	std::string abc_sname = abc_name.substr(1);
+	if (abc_sname.substr(0, 5) == "ys__n") {
+		int sid = std::stoi(abc_sname.substr(5));
+		bool inv = abc_sname.back() == 'v';
+		for (auto sig : signal_list) {
+			if (sig.id == sid && sig.bit.wire != nullptr) {
+				std::stringstream sstr;
+				sstr << "$abc$" << map_autoidx << "$" << sig.bit.wire->name.substr(1);
+				if (sig.bit.wire->width != 1)
+					sstr << "[" << sig.bit.offset << "]";
+				if (inv)
+					sstr << "_inv";
+				if (orig_wire != nullptr)
+					*orig_wire = sig.bit.wire;
+				return sstr.str();
+			}
+		}
+	}
 	std::stringstream sstr;
 	sstr << "$abc$" << map_autoidx << "$" << abc_name.substr(1);
 	return sstr.str();
@@ -353,12 +371,12 @@ void dump_loop_graph(FILE *f, int &nr, std::map<int, std::set<int>> &edges, std:
 	}
 
 	for (auto n : nodes)
-		fprintf(f, "  n%d [label=\"%s\\nid=%d, count=%d\"%s];\n", n, log_signal(signal_list[n].bit),
+		fprintf(f, "  ys__n%d [label=\"%s\\nid=%d, count=%d\"%s];\n", n, log_signal(signal_list[n].bit),
 				n, in_counts[n], workpool.count(n) ? ", shape=box" : "");
 
 	for (auto &e : edges)
 	for (auto n : e.second)
-		fprintf(f, "  n%d -> n%d;\n", e.first, n);
+		fprintf(f, "  ys__n%d -> ys__n%d;\n", e.first, n);
 
 	fprintf(f, "}\n");
 }
@@ -624,7 +642,7 @@ struct abc_output_filter
 void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::string script_file, std::string exe_file,
 		std::string liberty_file, std::string constr_file, bool cleanup, vector<int> lut_costs, bool dff_mode, std::string clk_str,
 		bool keepff, std::string delay_target, std::string sop_inputs, std::string sop_products, std::string lutin_shared, bool fast_mode,
-		const std::vector<RTLIL::Cell*> &cells, bool show_tempdir, bool sop_mode)
+		const std::vector<RTLIL::Cell*> &cells, bool show_tempdir, bool sop_mode, bool abc_dress)
 {
 	module = current_module;
 	map_autoidx = autoidx++;
@@ -728,7 +746,8 @@ void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::strin
 
 	for (size_t pos = abc_script.find("{S}"); pos != std::string::npos; pos = abc_script.find("{S}", pos))
 		abc_script = abc_script.substr(0, pos) + lutin_shared + abc_script.substr(pos+3);
-
+	if (abc_dress)
+		abc_script += "; dress";
 	abc_script += stringf("; write_blif %s/output.blif", tempdir_name.c_str());
 	abc_script = add_echos_to_abc_cmd(abc_script);
 
@@ -784,7 +803,7 @@ void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::strin
 	for (auto &si : signal_list) {
 		if (!si.is_port || si.type != G(NONE))
 			continue;
-		fprintf(f, " n%d", si.id);
+		fprintf(f, " ys__n%d", si.id);
 		pi_map[count_input++] = log_signal(si.bit);
 	}
 	if (count_input == 0)
@@ -796,17 +815,17 @@ void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::strin
 	for (auto &si : signal_list) {
 		if (!si.is_port || si.type == G(NONE))
 			continue;
-		fprintf(f, " n%d", si.id);
+		fprintf(f, " ys__n%d", si.id);
 		po_map[count_output++] = log_signal(si.bit);
 	}
 	fprintf(f, "\n");
 
 	for (auto &si : signal_list)
-		fprintf(f, "# n%-5d %s\n", si.id, log_signal(si.bit));
+		fprintf(f, "# ys__n%-5d %s\n", si.id, log_signal(si.bit));
 
 	for (auto &si : signal_list) {
 		if (si.bit.wire == NULL) {
-			fprintf(f, ".names n%d\n", si.id);
+			fprintf(f, ".names ys__n%d\n", si.id);
 			if (si.bit == RTLIL::State::S1)
 				fprintf(f, "1\n");
 		}
@@ -815,68 +834,68 @@ void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::strin
 	int count_gates = 0;
 	for (auto &si : signal_list) {
 		if (si.type == G(BUF)) {
-			fprintf(f, ".names n%d n%d\n", si.in1, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d\n", si.in1, si.id);
 			fprintf(f, "1 1\n");
 		} else if (si.type == G(NOT)) {
-			fprintf(f, ".names n%d n%d\n", si.in1, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d\n", si.in1, si.id);
 			fprintf(f, "0 1\n");
 		} else if (si.type == G(AND)) {
-			fprintf(f, ".names n%d n%d n%d\n", si.in1, si.in2, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.id);
 			fprintf(f, "11 1\n");
 		} else if (si.type == G(NAND)) {
-			fprintf(f, ".names n%d n%d n%d\n", si.in1, si.in2, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.id);
 			fprintf(f, "0- 1\n");
 			fprintf(f, "-0 1\n");
 		} else if (si.type == G(OR)) {
-			fprintf(f, ".names n%d n%d n%d\n", si.in1, si.in2, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.id);
 			fprintf(f, "-1 1\n");
 			fprintf(f, "1- 1\n");
 		} else if (si.type == G(NOR)) {
-			fprintf(f, ".names n%d n%d n%d\n", si.in1, si.in2, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.id);
 			fprintf(f, "00 1\n");
 		} else if (si.type == G(XOR)) {
-			fprintf(f, ".names n%d n%d n%d\n", si.in1, si.in2, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.id);
 			fprintf(f, "01 1\n");
 			fprintf(f, "10 1\n");
 		} else if (si.type == G(XNOR)) {
-			fprintf(f, ".names n%d n%d n%d\n", si.in1, si.in2, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.id);
 			fprintf(f, "00 1\n");
 			fprintf(f, "11 1\n");
 		} else if (si.type == G(ANDNOT)) {
-			fprintf(f, ".names n%d n%d n%d\n", si.in1, si.in2, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.id);
 			fprintf(f, "10 1\n");
 		} else if (si.type == G(ORNOT)) {
-			fprintf(f, ".names n%d n%d n%d\n", si.in1, si.in2, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.id);
 			fprintf(f, "1- 1\n");
 			fprintf(f, "-0 1\n");
 		} else if (si.type == G(MUX)) {
-			fprintf(f, ".names n%d n%d n%d n%d\n", si.in1, si.in2, si.in3, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.in3, si.id);
 			fprintf(f, "1-0 1\n");
 			fprintf(f, "-11 1\n");
 		} else if (si.type == G(AOI3)) {
-			fprintf(f, ".names n%d n%d n%d n%d\n", si.in1, si.in2, si.in3, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.in3, si.id);
 			fprintf(f, "-00 1\n");
 			fprintf(f, "0-0 1\n");
 		} else if (si.type == G(OAI3)) {
-			fprintf(f, ".names n%d n%d n%d n%d\n", si.in1, si.in2, si.in3, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.in3, si.id);
 			fprintf(f, "00- 1\n");
 			fprintf(f, "--0 1\n");
 		} else if (si.type == G(AOI4)) {
-			fprintf(f, ".names n%d n%d n%d n%d n%d\n", si.in1, si.in2, si.in3, si.in4, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.in3, si.in4, si.id);
 			fprintf(f, "-0-0 1\n");
 			fprintf(f, "-00- 1\n");
 			fprintf(f, "0--0 1\n");
 			fprintf(f, "0-0- 1\n");
 		} else if (si.type == G(OAI4)) {
-			fprintf(f, ".names n%d n%d n%d n%d n%d\n", si.in1, si.in2, si.in3, si.in4, si.id);
+			fprintf(f, ".names ys__n%d ys__n%d ys__n%d ys__n%d ys__n%d\n", si.in1, si.in2, si.in3, si.in4, si.id);
 			fprintf(f, "00-- 1\n");
 			fprintf(f, "--00 1\n");
 		} else if (si.type == G(FF)) {
 			if (si.init == State::S0 || si.init == State::S1) {
-				fprintf(f, ".latch n%d n%d %d\n", si.in1, si.id, si.init == State::S1 ? 1 : 0);
+				fprintf(f, ".latch ys__n%d ys__n%d %d\n", si.in1, si.id, si.init == State::S1 ? 1 : 0);
 				recover_init = true;
 			} else
-				fprintf(f, ".latch n%d n%d 2\n", si.in1, si.id);
+				fprintf(f, ".latch ys__n%d ys__n%d 2\n", si.in1, si.id);
 		} else if (si.type != G(NONE))
 			log_abort();
 		if (si.type != G(NONE))
@@ -889,7 +908,6 @@ void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::strin
 	log("Extracted %d gates and %d wires to a netlist network with %d inputs and %d outputs.\n",
 			count_gates, GetSize(signal_list), count_input, count_output);
 	log_push();
-
 	if (count_output > 0)
 	{
 		log_header(design, "Executing ABC.\n");
@@ -988,7 +1006,10 @@ void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::strin
 			log_error("ABC output file does not contain a module `netlist'.\n");
 		for (auto &it : mapped_mod->wires_) {
 			RTLIL::Wire *w = it.second;
-			RTLIL::Wire *wire = module->addWire(remap_name(w->name));
+			RTLIL::Wire *orig_wire = nullptr;
+			RTLIL::Wire *wire = module->addWire(remap_name(w->name, &orig_wire));
+			if (orig_wire != nullptr && orig_wire->attributes.count("\\src"))
+				wire->attributes["\\src"] = orig_wire->attributes["\\src"];
 			if (markgroups) wire->attributes["\\abcgroup"] = map_autoidx;
 			design->select(module, wire);
 		}
@@ -1213,7 +1234,7 @@ void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::strin
 		for (auto &si : signal_list)
 			if (si.is_port) {
 				char buffer[100];
-				snprintf(buffer, 100, "\\n%d", si.id);
+				snprintf(buffer, 100, "\\ys__n%d", si.id);
 				RTLIL::SigSig conn;
 				if (si.type != G(NONE)) {
 					conn.first = si.bit;
@@ -1407,6 +1428,11 @@ struct AbcPass : public Pass {
 		log("        this attribute is a unique integer for each ABC process started. This\n");
 		log("        is useful for debugging the partitioning of clock domains.\n");
 		log("\n");
+		log("    -dress\n");
+		log("        run the 'dress' command after all other ABC commands. This aims to\n");
+		log("        preserve naming by an equivalence check between the original and post-ABC\n");
+		log("        netlists (experimental).\n");
+		log("\n");
 		log("When neither -liberty nor -lut is used, the Yosys standard cell library is\n");
 		log("loaded into ABC before the ABC script is executed.\n");
 		log("\n");
@@ -1441,6 +1467,7 @@ struct AbcPass : public Pass {
 		std::string delay_target, sop_inputs, sop_products, lutin_shared = "-S 1";
 		bool fast_mode = false, dff_mode = false, keepff = false, cleanup = true;
 		bool show_tempdir = false, sop_mode = false;
+		bool abc_dress = false;
 		vector<int> lut_costs;
 		markgroups = false;
 
@@ -1555,6 +1582,10 @@ struct AbcPass : public Pass {
 				map_mux16 = true;
 				continue;
 			}
+			if (arg == "-dress") {
+				abc_dress = true;
+				continue;
+			}
 			if (arg == "-g" && argidx+1 < args.size()) {
 				for (auto g : split_tokens(args[++argidx], ",")) {
 					vector<string> gate_list;
@@ -1704,7 +1735,7 @@ struct AbcPass : public Pass {
 
 			if (!dff_mode || !clk_str.empty()) {
 				abc_module(design, mod, script_file, exe_file, liberty_file, constr_file, cleanup, lut_costs, dff_mode, clk_str, keepff,
-						delay_target, sop_inputs, sop_products, lutin_shared, fast_mode, mod->selected_cells(), show_tempdir, sop_mode);
+						delay_target, sop_inputs, sop_products, lutin_shared, fast_mode, mod->selected_cells(), show_tempdir, sop_mode, abc_dress);
 				continue;
 			}
 
@@ -1849,7 +1880,7 @@ struct AbcPass : public Pass {
 				en_polarity = std::get<2>(it.first);
 				en_sig = assign_map(std::get<3>(it.first));
 				abc_module(design, mod, script_file, exe_file, liberty_file, constr_file, cleanup, lut_costs, !clk_sig.empty(), "$",
-						keepff, delay_target, sop_inputs, sop_products, lutin_shared, fast_mode, it.second, show_tempdir, sop_mode);
+						keepff, delay_target, sop_inputs, sop_products, lutin_shared, fast_mode, it.second, show_tempdir, sop_mode, abc_dress);
 				assign_map.set(mod);
 			}
 		}
diff --git a/passes/techmap/dfflibmap.cc b/passes/techmap/dfflibmap.cc
index b0528d473..274177a68 100644
--- a/passes/techmap/dfflibmap.cc
+++ b/passes/techmap/dfflibmap.cc
@@ -660,8 +660,8 @@ struct DfflibmapPass : public Pass {
 		map_adff_to_dff("$_DFF_PP0_", "$_DFF_P_");
 		map_adff_to_dff("$_DFF_PP1_", "$_DFF_P_");
 
- 		log("  final dff cell mappings:\n");
- 		logmap_all();
+		log("  final dff cell mappings:\n");
+		logmap_all();
 
 		for (auto &it : design->modules_)
 			if (design->selected(it.second) && !it.second->get_bool_attribute("\\blackbox"))
diff --git a/passes/techmap/flowmap.cc b/passes/techmap/flowmap.cc
index ddbd7bf5d..0b7931e48 100644
--- a/passes/techmap/flowmap.cc
+++ b/passes/techmap/flowmap.cc
@@ -132,9 +132,9 @@ static void dump_dot_graph(string filename,
                            pool<RTLIL::SigBit> nodes, dict<RTLIL::SigBit, pool<RTLIL::SigBit>> edges,
                            pool<RTLIL::SigBit> inputs, pool<RTLIL::SigBit> outputs,
                            std::function<GraphStyle(RTLIL::SigBit)> node_style =
-                           		[](RTLIL::SigBit) { return GraphStyle{}; },
+                                   [](RTLIL::SigBit) { return GraphStyle{}; },
                            std::function<GraphStyle(RTLIL::SigBit, RTLIL::SigBit)> edge_style =
-                           		[](RTLIL::SigBit, RTLIL::SigBit) { return GraphStyle{}; },
+                                   [](RTLIL::SigBit, RTLIL::SigBit) { return GraphStyle{}; },
                            string name = "")
 {
 	FILE *f = fopen(filename.c_str(), "w");
diff --git a/techlibs/ecp5/cells_sim.v b/techlibs/ecp5/cells_sim.v
index 507ab1beb..f27540bd7 100644
--- a/techlibs/ecp5/cells_sim.v
+++ b/techlibs/ecp5/cells_sim.v
@@ -57,7 +57,7 @@ module TRELLIS_RAM16X2 (
 	input RAD0, RAD1, RAD2, RAD3,
 	output DO0, DO1
 );
-  	parameter WCKMUX = "WCK";
+	parameter WCKMUX = "WCK";
 	parameter WREMUX = "WRE";
 	parameter INITVAL_0 = 16'h0000;
 	parameter INITVAL_1 = 16'h0000;
@@ -104,7 +104,7 @@ module TRELLIS_DPR16X4 (
 	input [3:0] RAD,
 	output [3:0] DO
 );
-  	parameter WCKMUX = "WCK";
+	parameter WCKMUX = "WCK";
 	parameter WREMUX = "WRE";
 	parameter [63:0] INITVAL = 64'h0000000000000000;
 
diff --git a/techlibs/ecp5/synth_ecp5.cc b/techlibs/ecp5/synth_ecp5.cc
index 2e9176a84..bda03d251 100644
--- a/techlibs/ecp5/synth_ecp5.cc
+++ b/techlibs/ecp5/synth_ecp5.cc
@@ -268,9 +268,9 @@ struct SynthEcp5Pass : public ScriptPass
 			}
 			run("techmap -map +/ecp5/latches_map.v");
 			if (nomux)
-				run("abc -lut 4");
+				run("abc -lut 4 -dress");
 			else
-				run("abc -lut 4:7");
+				run("abc -lut 4:7 -dress");
 			run("clean");
 		}
 
diff --git a/techlibs/greenpak4/cells_map.v b/techlibs/greenpak4/cells_map.v
index b971a51fa..51c85183d 100644
--- a/techlibs/greenpak4/cells_map.v
+++ b/techlibs/greenpak4/cells_map.v
@@ -112,14 +112,14 @@ module GP_OBUFT(input IN, input OE, output OUT);
 endmodule
 
 module \$lut (A, Y);
-  parameter WIDTH = 0;
-  parameter LUT = 0;
+	parameter WIDTH = 0;
+	parameter LUT = 0;
 
-  input [WIDTH-1:0] A;
-  output Y;
+	input [WIDTH-1:0] A;
+	output Y;
 
-  generate
-    if (WIDTH == 1) begin
+	generate
+		if (WIDTH == 1) begin
 		if(LUT == 2'b01) begin
 			GP_INV _TECHMAP_REPLACE_ (.OUT(Y), .IN(A[0]) );
 		end
@@ -127,22 +127,22 @@ module \$lut (A, Y);
 			GP_2LUT #(.INIT({2'b00, LUT})) _TECHMAP_REPLACE_ (.OUT(Y),
 				.IN0(A[0]), .IN1(1'b0));
 		end
-    end else
-    if (WIDTH == 2) begin
-      GP_2LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
-      	.IN0(A[0]), .IN1(A[1]));
-    end else
-    if (WIDTH == 3) begin
-      GP_3LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
-      	.IN0(A[0]), .IN1(A[1]), .IN2(A[2]));
-    end else
-    if (WIDTH == 4) begin
-      GP_4LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
-      	.IN0(A[0]), .IN1(A[1]), .IN2(A[2]), .IN3(A[3]));
-    end else begin
-      wire _TECHMAP_FAIL_ = 1;
-    end
-  endgenerate
+		end else
+		if (WIDTH == 2) begin
+			GP_2LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
+				.IN0(A[0]), .IN1(A[1]));
+		end else
+		if (WIDTH == 3) begin
+			GP_3LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
+				.IN0(A[0]), .IN1(A[1]), .IN2(A[2]));
+		end else
+		if (WIDTH == 4) begin
+			GP_4LUT #(.INIT(LUT)) _TECHMAP_REPLACE_ (.OUT(Y),
+				.IN0(A[0]), .IN1(A[1]), .IN2(A[2]), .IN3(A[3]));
+		end else begin
+			wire _TECHMAP_FAIL_ = 1;
+		end
+	endgenerate
 endmodule
 
 module \$__COUNT_ (CE, CLK, OUT, POUT, RST, UP);
diff --git a/techlibs/ice40/synth_ice40.cc b/techlibs/ice40/synth_ice40.cc
index a13a81246..621b0b2bc 100644
--- a/techlibs/ice40/synth_ice40.cc
+++ b/techlibs/ice40/synth_ice40.cc
@@ -315,7 +315,7 @@ struct SynthIce40Pass : public ScriptPass
 				run("techmap -map +/gate2lut.v -D LUT_WIDTH=4", "(only if -noabc)");
 			}
 			if (!noabc) {
-				run(abc + " -lut 4", "(skip if -noabc)");
+				run(abc + " -dress -lut 4", "(skip if -noabc)");
 			}
 			run("clean");
 			if (relut || help_mode) {
diff --git a/tests/opt/opt_ff.v b/tests/opt/opt_ff.v
new file mode 100644
index 000000000..a01b64b61
--- /dev/null
+++ b/tests/opt/opt_ff.v
@@ -0,0 +1,21 @@
+module top(
+    input clk,
+    input rst,
+    input [2:0] a,
+    output [1:0] b
+);
+    reg [2:0] b_reg;
+    initial begin
+        b_reg <= 3'b0;
+    end
+
+    assign b = b_reg[1:0];
+    always @(posedge clk or posedge rst) begin
+        if(rst) begin
+            b_reg <= 3'b0;
+        end else begin
+            b_reg <= a;
+        end
+    end
+endmodule
+
diff --git a/tests/opt/opt_ff.ys b/tests/opt/opt_ff.ys
new file mode 100644
index 000000000..704c7acf3
--- /dev/null
+++ b/tests/opt/opt_ff.ys
@@ -0,0 +1,3 @@
+read_verilog opt_ff.v
+synth_ice40
+ice40_unlut
diff --git a/tests/simple/hierdefparam.v b/tests/simple/hierdefparam.v
index ff92c38bd..c9368ca7a 100644
--- a/tests/simple/hierdefparam.v
+++ b/tests/simple/hierdefparam.v
@@ -1,3 +1,5 @@
+`default_nettype none
+
 module hierdefparam_top(input [7:0] A, output [7:0] Y);
   generate begin:foo
     hierdefparam_a mod_a(.A(A), .Y(Y));
diff --git a/tests/various/hierarchy.sh b/tests/various/hierarchy.sh
new file mode 100644
index 000000000..d33a247be
--- /dev/null
+++ b/tests/various/hierarchy.sh
@@ -0,0 +1,59 @@
+#!/usr/bin/env bash
+# Simple test of hierarchy -auto-top.
+
+set -e
+
+echo -n "  TOP first - "
+../../yosys -s - <<- EOY | grep "Automatically selected TOP as design top module"
+  read_verilog << EOV
+    module TOP(a, y);
+      input a;
+      output [31:0] y;
+
+      aoi12 p [31:0] (a, y);
+    endmodule
+
+    module aoi12(a, y);
+      input a;
+      output y;
+      assign y = ~a;
+    endmodule
+  EOV
+  hierarchy -auto-top
+EOY
+
+echo -n "  TOP last - "
+../../yosys -s - <<- EOY | grep "Automatically selected TOP as design top module"
+  read_verilog << EOV
+    module aoi12(a, y);
+      input a;
+      output y;
+      assign y = ~a;
+    endmodule
+
+    module TOP(a, y);
+      input a;
+      output [31:0] y;
+
+      aoi12 foo (a, y);
+    endmodule
+  EOV
+  hierarchy -auto-top
+EOY
+
+echo -n "  no explicit top - "
+../../yosys -s - <<- EOY | grep "Automatically selected noTop as design top module."
+  read_verilog << EOV
+    module aoi12(a, y);
+      input a;
+      output y;
+      assign y = ~a;
+    endmodule
+
+    module noTop(a, y);
+      input a;
+      output [31:0] y;
+    endmodule
+  EOV
+  hierarchy -auto-top
+EOY
diff --git a/tests/various/run-test.sh b/tests/various/run-test.sh
index 67e1beb23..d49553ede 100755
--- a/tests/various/run-test.sh
+++ b/tests/various/run-test.sh
@@ -1,6 +1,14 @@
-#!/bin/bash
+#!/usr/bin/env bash
 set -e
 for x in *.ys; do
 	echo "Running $x.."
 	../../yosys -ql ${x%.ys}.log $x
 done
+# Run any .sh files in this directory (with the exception of the file - run-test.sh
+shell_tests=$(echo *.sh | sed -e 's/run-test.sh//')
+if [ "$shell_tests" ]; then
+    for s in $shell_tests; do
+        echo "Running $s.."
+        bash $s
+    done
+fi