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

30 files changed, 2528 insertions, 1001 deletions

diff --git a/passes/cmds/Makefile.inc b/passes/cmds/Makefile.inc
index c7edc30fb..07a5d3ddc 100644
--- a/passes/cmds/Makefile.inc
+++ b/passes/cmds/Makefile.inc
@@ -32,3 +32,4 @@ OBJS += passes/cmds/chtype.o
 OBJS += passes/cmds/blackbox.o
 OBJS += passes/cmds/ltp.o
 OBJS += passes/cmds/bugpoint.o
+OBJS += passes/cmds/scratchpad.o
diff --git a/passes/cmds/autoname.cc b/passes/cmds/autoname.cc
index 4614a8153..50632201e 100644
--- a/passes/cmds/autoname.cc
+++ b/passes/cmds/autoname.cc
@@ -56,7 +56,7 @@ int autoname_worker(Module *module)
 			for (auto &conn : cell->connections()) {
 				string suffix = stringf("_%s", log_id(conn.first));
 				for (auto bit : conn.second)
-					if (bit.wire != nullptr && bit.wire->name[0] == '$') {
+					if (bit.wire != nullptr && bit.wire->name[0] == '$' && !bit.wire->port_id) {
 						IdString new_name(cell->name.str() + suffix);
 						int score = wire_score.at(bit.wire);
 						if (cell->output(conn.first)) score = 0;
diff --git a/passes/cmds/scc.cc b/passes/cmds/scc.cc
index 99f4fbae8..ad0554bae 100644
--- a/passes/cmds/scc.cc
+++ b/passes/cmds/scc.cc
@@ -301,42 +301,41 @@ struct SccPass : public Pass {
 		RTLIL::Selection newSelection(false);
 		int scc_counter = 0;
 
-		for (auto &mod_it : design->modules_)
-			if (design->selected(mod_it.second))
-			{
-				SccWorker worker(design, mod_it.second, nofeedbackMode, allCellTypes, maxDepth);
+		for (auto mod : design->selected_modules())
+		{
+			SccWorker worker(design, mod, nofeedbackMode, allCellTypes, maxDepth);
 
-				if (!setAttr.empty())
+			if (!setAttr.empty())
+			{
+				for (const auto &cells : worker.sccList)
 				{
-					for (const auto &cells : worker.sccList)
+					for (auto attr : setAttr)
 					{
-						for (auto attr : setAttr)
-						{
-							IdString attr_name(RTLIL::escape_id(attr.first));
-							string attr_valstr = attr.second;
-							string index = stringf("%d", scc_counter);
-
-							for (size_t pos = 0; (pos = attr_valstr.find("{}", pos)) != string::npos; pos += index.size())
-								attr_valstr.replace(pos, 2, index);
+						IdString attr_name(RTLIL::escape_id(attr.first));
+						string attr_valstr = attr.second;
+						string index = stringf("%d", scc_counter);
 
-							Const attr_value(attr_valstr);
+						for (size_t pos = 0; (pos = attr_valstr.find("{}", pos)) != string::npos; pos += index.size())
+							attr_valstr.replace(pos, 2, index);
 
-							for (auto cell : cells)
-								cell->attributes[attr_name] = attr_value;
-						}
+						Const attr_value(attr_valstr);
 
-						scc_counter++;
+						for (auto cell : cells)
+							cell->attributes[attr_name] = attr_value;
 					}
-				}
-				else
-				{
-					scc_counter += GetSize(worker.sccList);
-				}
 
-				if (selectMode)
-					worker.select(newSelection);
+					scc_counter++;
+				}
+			}
+			else
+			{
+				scc_counter += GetSize(worker.sccList);
 			}
 
+			if (selectMode)
+				worker.select(newSelection);
+		}
+
 		if (expect >= 0) {
 			if (scc_counter == expect)
 				log("Found and expected %d SCCs.\n", scc_counter);
diff --git a/passes/cmds/scratchpad.cc b/passes/cmds/scratchpad.cc
new file mode 100644
index 000000000..34ec0863a
--- /dev/null
+++ b/passes/cmds/scratchpad.cc
@@ -0,0 +1,141 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *                2019  Nina Engelhardt <nak@symbioticeda.com>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "kernel/register.h"
+#include "kernel/rtlil.h"
+#include "kernel/log.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct ScratchpadPass : public Pass {
+	ScratchpadPass() : Pass("scratchpad", "get/set values in the scratchpad") { }
+	void help() YS_OVERRIDE
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    scratchpad [options]\n");
+		log("\n");
+		log("This pass allows to read and modify values from the scratchpad of the current\n");
+		log("design. Options:\n");
+		log("\n");
+		log("    -get <identifier>\n");
+		log("        print the value saved in the scratchpad under the given identifier.\n");
+		log("\n");
+		log("    -set <identifier> <value>\n");
+		log("        save the given value in the scratchpad under the given identifier.\n");
+		log("\n");
+		log("    -unset <identifier>\n");
+		log("        remove the entry for the given identifier from the scratchpad.\n");
+		log("\n");
+		log("    -copy <identifier_from> <identifier_to>\n");
+		log("        copy the value of the first identifier to the second identifier.\n");
+		log("\n");
+		log("    -assert <identifier> <value>\n");
+		log("        assert that the entry for the given identifier is set to the given value.\n");
+		log("\n");
+		log("    -assert-set <identifier>\n");
+		log("        assert that the entry for the given identifier exists.\n");
+		log("\n");
+		log("    -assert-unset <identifier>\n");
+		log("        assert that the entry for the given identifier does not exist.\n");
+		log("\n");
+		log("The identifier may not contain whitespace. By convention, it is usually prefixed\n");
+		log("by the name of the pass that uses it, e.g. 'opt.did_something'. If the value\n");
+		log("contains whitespace, it must be enclosed in double quotes.\n");
+		log("\n");
+	}
+
+	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
+	{
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++)
+		{
+			if (args[argidx] == "-get" && argidx+1 < args.size()) {
+				string identifier = args[++argidx];
+				if (design->scratchpad.count(identifier)) {
+					log("%s\n", design->scratchpad_get_string(identifier).c_str());
+				} else if (RTLIL::constpad.count(identifier)) {
+					log("%s\n", RTLIL::constpad.at(identifier).c_str());
+				} else {
+					log("\"%s\" not set\n", identifier.c_str());
+				}
+				continue;
+			}
+			if (args[argidx] == "-set" && argidx+2 < args.size()) {
+				string identifier = args[++argidx];
+				if (RTLIL::constpad.count(identifier))
+					log_error("scratchpad entry \"%s\" is a global constant\n", identifier.c_str());
+				string value = args[++argidx];
+				if (value.front() == '\"' && value.back() == '\"') value = value.substr(1, value.size() - 2);
+				design->scratchpad_set_string(identifier, value);
+				continue;
+			}
+			if (args[argidx] == "-unset" && argidx+1 < args.size()) {
+				string identifier = args[++argidx];
+				design->scratchpad_unset(identifier);
+				continue;
+			}
+			if (args[argidx] == "-copy" && argidx+2 < args.size()) {
+				string identifier_from = args[++argidx];
+				string identifier_to = args[++argidx];
+				string value;
+				if (design->scratchpad.count(identifier_from))
+					value = design->scratchpad_get_string(identifier_from);
+				else if (RTLIL::constpad.count(identifier_from))
+					value = RTLIL::constpad.at(identifier_from);
+				else
+					log_error("\"%s\" not set\n", identifier_from.c_str());
+				if (RTLIL::constpad.count(identifier_to))
+					log_error("scratchpad entry \"%s\" is a global constant\n", identifier_to.c_str());
+				design->scratchpad_set_string(identifier_to, value);
+				continue;
+			}
+			if (args[argidx] == "-assert" && argidx+2 < args.size()) {
+				string identifier = args[++argidx];
+				string expected = args[++argidx];
+				if (expected.front() == '\"' && expected.back() == '\"') expected = expected.substr(1, expected.size() - 2);
+				if (design->scratchpad.count(identifier) == 0)
+					log_error("scratchpad entry '%s' is not defined\n", identifier.c_str());
+				string value = design->scratchpad_get_string(identifier);
+				if (value != expected) {
+					log_error("scratchpad entry '%s' is set to '%s' instead of the asserted '%s'\n",
+					           identifier.c_str(), value.c_str(), expected.c_str());
+				}
+				continue;
+			}
+			if (args[argidx] == "-assert-set" && argidx+1 < args.size()) {
+				string identifier = args[++argidx];
+				if (design->scratchpad.count(identifier) == 0)
+					log_error("scratchpad entry '%s' is not defined\n", identifier.c_str());
+				continue;
+			}
+			if (args[argidx] == "-assert-unset" && argidx+1 < args.size()) {
+				string identifier = args[++argidx];
+				if (design->scratchpad.count(identifier) > 0)
+					log_error("scratchpad entry '%s' is defined\n", identifier.c_str());
+				continue;
+			}
+			break;
+		}
+		extra_args(args, argidx, design, false);
+	}
+} ScratchpadPass;
+PRIVATE_NAMESPACE_END
diff --git a/passes/equiv/equiv_opt.cc b/passes/equiv/equiv_opt.cc
index c7e6d71a6..7c6c2e685 100644
--- a/passes/equiv/equiv_opt.cc
+++ b/passes/equiv/equiv_opt.cc
@@ -44,6 +44,10 @@ struct EquivOptPass:public ScriptPass
 		log("        expand the modules in this file before proving equivalence. this is\n");
 		log("        useful for handling architecture-specific primitives.\n");
 		log("\n");
+		log("    -blacklist <file>\n");
+		log("        Do not match cells or signals that match the names in the file\n");
+		log("        (passed to equiv_make).\n");
+		log("\n");
 		log("    -assert\n");
 		log("        produce an error if the circuits are not equivalent.\n");
 		log("\n");
@@ -61,13 +65,14 @@ struct EquivOptPass:public ScriptPass
 		log("\n");
 	}
 
-	std::string command, techmap_opts;
+	std::string command, techmap_opts, make_opts;
 	bool assert, undef, multiclock, async2sync;
 
 	void clear_flags() YS_OVERRIDE
 	{
 		command = "";
 		techmap_opts = "";
+		make_opts = "";
 		assert = false;
 		undef = false;
 		multiclock = false;
@@ -93,6 +98,10 @@ struct EquivOptPass:public ScriptPass
 				techmap_opts += " -map " + args[++argidx];
 				continue;
 			}
+			if (args[argidx] == "-blacklist" && argidx + 1 < args.size()) {
+				make_opts += " -blacklist " + args[++argidx];
+				continue;
+			}
 			if (args[argidx] == "-assert") {
 				assert = true;
 				continue;
@@ -170,7 +179,12 @@ struct EquivOptPass:public ScriptPass
 				run("clk2fflogic", "(only with -multiclock)");
 			if (async2sync || help_mode)
 				run("async2sync", " (only with -async2sync)");
-			run("equiv_make gold gate equiv");
+			string opts;
+			if (help_mode)
+				opts = " -blacklist <filename> ...";
+			else
+				opts = make_opts;
+			run("equiv_make" + opts + " gold gate equiv");
 			if (help_mode)
 				run("equiv_induct [-undef] equiv");
 			else if (undef)
diff --git a/passes/fsm/fsm_detect.cc b/passes/fsm/fsm_detect.cc
index fb3896669..a1c8067b4 100644
--- a/passes/fsm/fsm_detect.cc
+++ b/passes/fsm/fsm_detect.cc
@@ -34,13 +34,20 @@ static SigSet<sig2driver_entry_t> sig2driver, sig2user;
 static std::set<RTLIL::Cell*> muxtree_cells;
 static SigPool sig_at_port;
 
-static bool check_state_mux_tree(RTLIL::SigSpec old_sig, RTLIL::SigSpec sig, pool<Cell*> &recursion_monitor)
+static bool check_state_mux_tree(RTLIL::SigSpec old_sig, RTLIL::SigSpec sig, pool<Cell*> &recursion_monitor, dict<RTLIL::SigSpec, bool> &mux_tree_cache)
 {
+	if (mux_tree_cache.find(sig) != mux_tree_cache.end())
+		return mux_tree_cache.at(sig);
+
 	if (sig.is_fully_const() || old_sig == sig) {
+ret_true:
+		mux_tree_cache[sig] = true;
 		return true;
 	}
 
 	if (sig_at_port.check_any(assign_map(sig))) {
+ret_false:
+		mux_tree_cache[sig] = false;
 		return false;
 	}
 
@@ -49,13 +56,13 @@ static bool check_state_mux_tree(RTLIL::SigSpec old_sig, RTLIL::SigSpec sig, poo
 	for (auto &cellport : cellport_list)
 	{
 		if ((cellport.first->type != "$mux" && cellport.first->type != "$pmux") || cellport.second != "\\Y") {
-			return false;
+			goto ret_false;
 		}
 
 		if (recursion_monitor.count(cellport.first)) {
 			log_warning("logic loop in mux tree at signal %s in module %s.\n",
 					log_signal(sig), RTLIL::id2cstr(module->name));
-			return false;
+			goto ret_false;
 		}
 
 		recursion_monitor.insert(cellport.first);
@@ -63,22 +70,22 @@ static bool check_state_mux_tree(RTLIL::SigSpec old_sig, RTLIL::SigSpec sig, poo
 		RTLIL::SigSpec sig_a = assign_map(cellport.first->getPort("\\A"));
 		RTLIL::SigSpec sig_b = assign_map(cellport.first->getPort("\\B"));
 
-		if (!check_state_mux_tree(old_sig, sig_a, recursion_monitor)) {
+		if (!check_state_mux_tree(old_sig, sig_a, recursion_monitor, mux_tree_cache)) {
 			recursion_monitor.erase(cellport.first);
-			return false;
+			goto ret_false;
 		}
 
 		for (int i = 0; i < sig_b.size(); i += sig_a.size())
-			if (!check_state_mux_tree(old_sig, sig_b.extract(i, sig_a.size()), recursion_monitor)) {
+			if (!check_state_mux_tree(old_sig, sig_b.extract(i, sig_a.size()), recursion_monitor, mux_tree_cache)) {
 				recursion_monitor.erase(cellport.first);
-				return false;
+				goto ret_false;
 			}
 
 		recursion_monitor.erase(cellport.first);
 		muxtree_cells.insert(cellport.first);
 	}
 
-	return true;
+	goto ret_true;
 }
 
 static bool check_state_users(RTLIL::SigSpec sig)
@@ -143,11 +150,12 @@ static void detect_fsm(RTLIL::Wire *wire)
 		pool<Cell*> recursion_monitor;
 		RTLIL::SigSpec sig_q = assign_map(cellport.first->getPort("\\Q"));
 		RTLIL::SigSpec sig_d = assign_map(cellport.first->getPort("\\D"));
+		dict<RTLIL::SigSpec, bool> mux_tree_cache;
 
 		if (sig_q != assign_map(wire))
 			continue;
 
-		looks_like_state_reg = check_state_mux_tree(sig_q, sig_d, recursion_monitor);
+		looks_like_state_reg = check_state_mux_tree(sig_q, sig_d, recursion_monitor, mux_tree_cache);
 		looks_like_good_state_reg = check_state_users(sig_q);
 
 		if (!looks_like_state_reg)
diff --git a/passes/memory/memory.cc b/passes/memory/memory.cc
index 712bc2537..cee63bdd8 100644
--- a/passes/memory/memory.cc
+++ b/passes/memory/memory.cc
@@ -35,6 +35,7 @@ struct MemoryPass : public Pass {
 		log("\n");
 		log("This pass calls all the other memory_* passes in a useful order:\n");
 		log("\n");
+		log("    opt_mem\n");
 		log("    memory_dff [-nordff]                (-memx implies -nordff)\n");
 		log("    opt_clean\n");
 		log("    memory_share\n");
@@ -81,6 +82,7 @@ struct MemoryPass : public Pass {
 		}
 		extra_args(args, argidx, design);
 
+		Pass::call(design, "opt_mem");
 		Pass::call(design, flag_nordff ? "memory_dff -nordff" : "memory_dff");
 		Pass::call(design, "opt_clean");
 		Pass::call(design, "memory_share");
diff --git a/passes/memory/memory_bram.cc b/passes/memory/memory_bram.cc
index aa8f94149..24478f2ee 100644
--- a/passes/memory/memory_bram.cc
+++ b/passes/memory/memory_bram.cc
@@ -134,6 +134,7 @@ struct rules_t
 		dict<string, int> min_limits, max_limits;
 		bool or_next_if_better, make_transp, make_outreg;
 		char shuffle_enable;
+		vector<vector<std::tuple<bool,IdString,Const>>> attributes;
 	};
 
 	dict<IdString, vector<bram_t>> brams;
@@ -327,6 +328,20 @@ struct rules_t
 				continue;
 			}
 
+			if (GetSize(tokens) >= 2 && tokens[0] == "attribute") {
+				data.attributes.emplace_back();
+				for (int idx = 1; idx < GetSize(tokens); idx++) {
+					size_t c1 = tokens[idx][0] == '!' ? 1 : 0;
+					size_t c2 = tokens[idx].find("=");
+					bool exists = (c1 == 0);
+					IdString key = RTLIL::escape_id(tokens[idx].substr(c1, c2));
+					Const val = c2 != std::string::npos ? tokens[idx].substr(c2+1) : RTLIL::Const(1);
+
+					data.attributes.back().emplace_back(exists, key, val);
+				}
+				continue;
+			}
+
 			syntax_error();
 		}
 	}
@@ -724,7 +739,7 @@ grow_read_ports:;
 					if (match.make_transp && wr_ports <= 1) {
 						pi.make_transp = true;
 						if (pi.clocks != 0) {
-							if (wr_ports == 1 && wr_clkdom != clkdom) {								
+							if (wr_ports == 1 && wr_clkdom != clkdom) {
 								log("        Bram port %c%d.%d cannot have soft transparency logic added as read and write clock domains differ.\n", pi.group + 'A', pi.index + 1, pi.dupidx + 1);
 								goto skip_bram_rport;
 							}
@@ -813,6 +828,43 @@ grow_read_ports:;
 			return false;
 		}
 
+		for (const auto &sums : match.attributes) {
+			bool found = false;
+			for (const auto &term : sums) {
+				bool exists = std::get<0>(term);
+				IdString key = std::get<1>(term);
+				const Const &value = std::get<2>(term);
+				auto it = cell->attributes.find(key);
+				if (it == cell->attributes.end()) {
+					if (exists)
+						continue;
+					found = true;
+					break;
+				}
+				else if (!exists)
+					continue;
+				if (it->second != value)
+					continue;
+				found = true;
+				break;
+			}
+			if (!found) {
+				std::stringstream ss;
+				bool exists = std::get<0>(sums.front());
+				if (!exists)
+					ss << "!";
+				IdString key = std::get<1>(sums.front());
+				ss << log_id(key);
+				const Const &value = std::get<2>(sums.front());
+				if (exists && value != Const(1))
+					ss << "=\"" << value.decode_string() << "\"";
+
+				log("    Rule for bram type %s rejected: requirement 'attribute %s ...' not met.\n",
+						log_id(match.name), ss.str().c_str());
+				return false;
+			}
+		}
+
 		if (mode == 1)
 			return true;
 	}
@@ -1100,6 +1152,43 @@ void handle_cell(Cell *cell, const rules_t &rules)
 				goto next_match_rule;
 			}
 
+			for (const auto &sums : match.attributes) {
+				bool found = false;
+				for (const auto &term : sums) {
+					bool exists = std::get<0>(term);
+					IdString key = std::get<1>(term);
+					const Const &value = std::get<2>(term);
+					auto it = cell->attributes.find(key);
+					if (it == cell->attributes.end()) {
+						if (exists)
+							continue;
+						found = true;
+						break;
+					}
+					else if (!exists)
+						continue;
+					if (it->second != value)
+						continue;
+					found = true;
+					break;
+				}
+				if (!found) {
+					std::stringstream ss;
+					bool exists = std::get<0>(sums.front());
+					if (!exists)
+						ss << "!";
+					IdString key = std::get<1>(sums.front());
+					ss << log_id(key);
+					const Const &value = std::get<2>(sums.front());
+					if (exists && value != Const(1))
+						ss << "=\"" << value.decode_string() << "\"";
+
+					log("    Rule for bram type %s (variant %d) rejected: requirement 'attribute %s ...' not met.\n",
+							log_id(bram.name), bram.variant, ss.str().c_str());
+					goto next_match_rule;
+				}
+			}
+
 			log("    Rule #%d for bram type %s (variant %d) accepted.\n", i+1, log_id(bram.name), bram.variant);
 
 			if (or_next_if_better || !best_rule_cache.empty())
@@ -1225,6 +1314,13 @@ struct MemoryBramPass : public Pass {
 		log("    dcells  .......  number of cells in 'data-direction'\n");
 		log("    cells  ........  total number of cells (acells*dcells*dups)\n");
 		log("\n");
+		log("A match containing the command 'attribute' followed by a list of space\n");
+		log("separated 'name[=string_value]' values requires that the memory contains any\n");
+		log("one of the given attribute name and string values (where specified), or name\n");
+		log("and integer 1 value (if no string_value given, since Verilog will interpret\n");
+		log("'(* attr *)' as '(* attr=1 *)').\n");
+		log("A name prefixed with '!' indicates that the attribute must not exist.\n");
+		log("\n");
 		log("The interface for the created bram instances is derived from the bram\n");
 		log("description. Use 'techmap' to convert the created bram instances into\n");
 		log("instances of the actual bram cells of your target architecture.\n");
diff --git a/passes/memory/memory_collect.cc b/passes/memory/memory_collect.cc
index 6acbce62f..9dcb3f024 100644
--- a/passes/memory/memory_collect.cc
+++ b/passes/memory/memory_collect.cc
@@ -218,6 +218,10 @@ Cell *handle_memory(Module *module, RTLIL::Memory *memory)
 	mem->setPort("\\RD_DATA", sig_rd_data);
 	mem->setPort("\\RD_EN", sig_rd_en);
 
+	// Copy attributes from RTLIL memory to $mem
+	for (auto attr : memory->attributes)
+		mem->attributes[attr.first] = attr.second;
+
 	for (auto c : memcells)
 		module->remove(c);
 
diff --git a/passes/opt/Makefile.inc b/passes/opt/Makefile.inc
index eb07e9452..002c1a6a1 100644
--- a/passes/opt/Makefile.inc
+++ b/passes/opt/Makefile.inc
@@ -1,6 +1,7 @@
 
 OBJS += passes/opt/opt.o
 OBJS += passes/opt/opt_merge.o
+OBJS += passes/opt/opt_mem.o
 OBJS += passes/opt/opt_muxtree.o
 OBJS += passes/opt/opt_reduce.o
 OBJS += passes/opt/opt_rmdff.o
diff --git a/passes/opt/opt_expr.cc b/passes/opt/opt_expr.cc
index 6cf66fb95..4a2f170b8 100644
--- a/passes/opt/opt_expr.cc
+++ b/passes/opt/opt_expr.cc
@@ -978,7 +978,7 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons
 		{
 			cover_list("opt.opt_expr.eqneq.cmpzero", "$eq", "$ne", cell->type.str());
 			log_debug("Replacing %s cell `%s' in module `%s' with %s.\n", log_id(cell->type), log_id(cell),
-					log_id(module), "$eq" ? "$logic_not" : "$reduce_bool");
+					log_id(module), cell->type == ID($eq) ? "$logic_not" : "$reduce_bool");
 			cell->type = cell->type == ID($eq) ? ID($logic_not) : ID($reduce_bool);
 			if (assign_map(cell->getPort(ID::A)).is_fully_zero()) {
 				cell->setPort(ID::A, cell->getPort(ID::B));
diff --git a/passes/opt/opt_mem.cc b/passes/opt/opt_mem.cc
new file mode 100644
index 000000000..98d3551eb
--- /dev/null
+++ b/passes/opt/opt_mem.cc
@@ -0,0 +1,143 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "kernel/yosys.h"
+#include "kernel/sigtools.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct OptMemWorker
+{
+	RTLIL::Design *design;
+	RTLIL::Module *module;
+	SigMap sigmap;
+	bool restart;
+
+	dict<IdString, vector<IdString>> memrd, memwr, meminit;
+	pool<IdString> remove_mem, remove_cells;
+
+	OptMemWorker(RTLIL::Module *module) : design(module->design), module(module), sigmap(module), restart(false)
+	{
+		for (auto &it : module->memories)
+		{
+			memrd[it.first];
+			memwr[it.first];
+			meminit[it.first];
+		}
+
+		for (auto cell : module->cells())
+		{
+			if (cell->type == ID($memrd)) {
+				IdString id = cell->getParam(ID(MEMID)).decode_string();
+				memrd.at(id).push_back(cell->name);
+			}
+
+			if (cell->type == ID($memwr)) {
+				IdString id = cell->getParam(ID(MEMID)).decode_string();
+				memwr.at(id).push_back(cell->name);
+			}
+
+			if (cell->type == ID($meminit)) {
+				IdString id = cell->getParam(ID(MEMID)).decode_string();
+				meminit.at(id).push_back(cell->name);
+			}
+		}
+	}
+
+	~OptMemWorker()
+	{
+		for (auto it : remove_mem)
+		{
+			for (auto cell_name : memrd[it])
+				module->remove(module->cell(cell_name));
+			for (auto cell_name : memwr[it])
+				module->remove(module->cell(cell_name));
+			for (auto cell_name : meminit[it])
+				module->remove(module->cell(cell_name));
+
+			delete module->memories.at(it);
+			module->memories.erase(it);
+		}
+
+		for (auto cell_name : remove_cells)
+			module->remove(module->cell(cell_name));
+	}
+
+	int run(RTLIL::Memory *mem)
+	{
+		if (restart || remove_mem.count(mem->name))
+			return 0;
+
+		if (memwr.at(mem->name).empty() && meminit.at(mem->name).empty()) {
+			log("Removing memory %s.%s with no write ports or init data.\n", log_id(module), log_id(mem));
+			remove_mem.insert(mem->name);
+			return 1;
+		}
+
+		return 0;
+	}
+};
+
+struct OptMemPass : public Pass {
+	OptMemPass() : Pass("opt_mem", "optimize memories") { }
+	void help() YS_OVERRIDE
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    opt_mem [options] [selection]\n");
+		log("\n");
+		log("This pass performs various optimizations on memories in the design.\n");
+		log("\n");
+	}
+	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
+	{
+		log_header(design, "Executing OPT_MEM pass (optimize memories).\n");
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++) {
+			// if (args[argidx] == "-nomux") {
+			// 	mode_nomux = true;
+			// 	continue;
+			// }
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		int total_count = 0;
+		for (auto module : design->selected_modules()) {
+			while (1) {
+				int cnt = 0;
+				OptMemWorker worker(module);
+				for (auto &it : module->memories)
+					if (module->selected(it.second))
+						cnt += worker.run(it.second);
+				if (!cnt && !worker.restart)
+					break;
+				total_count += cnt;
+			}
+		}
+
+		if (total_count)
+			design->scratchpad_set_bool("opt.did_something", true);
+		log("Performed a total of %d transformations.\n", total_count);
+	}
+} OptMemPass;
+
+PRIVATE_NAMESPACE_END
diff --git a/passes/opt/opt_share.cc b/passes/opt/opt_share.cc
index 2c456705c..f59f978a6 100644
--- a/passes/opt/opt_share.cc
+++ b/passes/opt/opt_share.cc
@@ -83,7 +83,9 @@ struct ExtSigSpec {
 	bool operator==(const ExtSigSpec &other) const { return is_signed == other.is_signed && sign == other.sign && sig == other.sig && semantics == other.semantics; }
 };
 
-#define BITWISE_OPS ID($_AND_), ID($_NAND_), ID($_OR_), ID($_NOR_), ID($_XOR_), ID($_XNOR_), ID($_ANDNOT_), ID($_ORNOT_), ID($and), ID($or), ID($xor), ID($xnor)
+#define FINE_BITWISE_OPS ID($_AND_), ID($_NAND_), ID($_OR_), ID($_NOR_), ID($_XOR_), ID($_XNOR_), ID($_ANDNOT_), ID($_ORNOT_)
+
+#define BITWISE_OPS FINE_BITWISE_OPS, ID($and), ID($or), ID($xor), ID($xnor)
 
 #define REDUCTION_OPS ID($reduce_and), ID($reduce_or), ID($reduce_xor), ID($reduce_xnor), ID($reduce_bool), ID($reduce_nand)
 
@@ -250,14 +252,19 @@ void merge_operators(RTLIL::Module *module, RTLIL::Cell *mux, const std::vector<
 		shared_op->setPort(ID(CO), alu_co.extract(0, conn_width));
 	}
 
-	shared_op->setParam(ID(Y_WIDTH), conn_width);
+	bool is_fine = shared_op->type.in(FINE_BITWISE_OPS);
+
+	if (!is_fine)
+		shared_op->setParam(ID(Y_WIDTH), conn_width);
 
 	if (decode_port(shared_op, ID::A, &assign_map) == operand) {
 		shared_op->setPort(ID::B, mux_to_oper);
-		shared_op->setParam(ID(B_WIDTH), max_width);
+		if (!is_fine)
+			shared_op->setParam(ID(B_WIDTH), max_width);
 	} else {
 		shared_op->setPort(ID::A, mux_to_oper);
-		shared_op->setParam(ID(A_WIDTH), max_width);
+		if (!is_fine)
+			shared_op->setParam(ID(A_WIDTH), max_width);
 	}
 }
 
diff --git a/passes/pmgen/Makefile.inc b/passes/pmgen/Makefile.inc
index 145d2ebf9..1a57bef7d 100644
--- a/passes/pmgen/Makefile.inc
+++ b/passes/pmgen/Makefile.inc
@@ -22,8 +22,9 @@ $(eval $(call add_extra_objs,passes/pmgen/ice40_wrapcarry_pm.h))
 # --------------------------------------
 
 OBJS += passes/pmgen/xilinx_dsp.o
-passes/pmgen/xilinx_dsp.o: passes/pmgen/xilinx_dsp_pm.h passes/pmgen/xilinx_dsp_CREG_pm.h passes/pmgen/xilinx_dsp_cascade_pm.h
+passes/pmgen/xilinx_dsp.o: passes/pmgen/xilinx_dsp_pm.h passes/pmgen/xilinx_dsp48a_pm.h passes/pmgen/xilinx_dsp_CREG_pm.h passes/pmgen/xilinx_dsp_cascade_pm.h
 $(eval $(call add_extra_objs,passes/pmgen/xilinx_dsp_pm.h))
+$(eval $(call add_extra_objs,passes/pmgen/xilinx_dsp48a_pm.h))
 $(eval $(call add_extra_objs,passes/pmgen/xilinx_dsp_CREG_pm.h))
 $(eval $(call add_extra_objs,passes/pmgen/xilinx_dsp_cascade_pm.h))
 
diff --git a/passes/pmgen/ice40_dsp.cc b/passes/pmgen/ice40_dsp.cc
index f60e67158..c364cd91a 100644
--- a/passes/pmgen/ice40_dsp.cc
+++ b/passes/pmgen/ice40_dsp.cc
@@ -73,11 +73,11 @@ void create_ice40_dsp(ice40_dsp_pm &pm)
 
 	// SB_MAC16 Input Interface
 	SigSpec A = st.sigA;
-	A.extend_u0(16, st.mul->getParam(ID(A_SIGNED)).as_bool());
+	A.extend_u0(16, st.mul->parameters.at(ID(A_SIGNED), State::S0).as_bool());
 	log_assert(GetSize(A) == 16);
 
 	SigSpec B = st.sigB;
-	B.extend_u0(16, st.mul->getParam(ID(B_SIGNED)).as_bool());
+	B.extend_u0(16, st.mul->parameters.at(ID(B_SIGNED), State::S0).as_bool());
 	log_assert(GetSize(B) == 16);
 
 	SigSpec CD = st.sigCD;
@@ -248,8 +248,8 @@ void create_ice40_dsp(ice40_dsp_pm &pm)
 	cell->setParam(ID(BOTADDSUB_CARRYSELECT), Const(0, 2));
 
 	cell->setParam(ID(MODE_8x8), State::S0);
-	cell->setParam(ID(A_SIGNED), st.mul->getParam(ID(A_SIGNED)).as_bool());
-	cell->setParam(ID(B_SIGNED), st.mul->getParam(ID(B_SIGNED)).as_bool());
+	cell->setParam(ID(A_SIGNED), st.mul->parameters.at(ID(A_SIGNED), State::S0).as_bool());
+	cell->setParam(ID(B_SIGNED), st.mul->parameters.at(ID(B_SIGNED), State::S0).as_bool());
 
 	if (st.ffO) {
 		if (st.o_lo)
diff --git a/passes/pmgen/ice40_dsp.pmg b/passes/pmgen/ice40_dsp.pmg
index 6b6d2b56f..9d649cb98 100644
--- a/passes/pmgen/ice40_dsp.pmg
+++ b/passes/pmgen/ice40_dsp.pmg
@@ -56,11 +56,16 @@ code sigA sigB sigH
 			break;
 		sigH.append(O[i]);
 	}
+	// This sigM could have no users if downstream sinks (e.g. $add) is
+	//   narrower than $mul result, for example
+	if (i == 0)
+		reject;
+
 	log_assert(nusers(O.extract_end(i)) <= 1);
 endcode
 
 code argQ ffA ffAholdmux ffArstmux ffAholdpol ffArstpol sigA clock clock_pol
-	if (mul->type != \SB_MAC16 || !param(mul, \A_REG).as_bool()) {
+	if (mul->type != \SB_MAC16 || !param(mul, \A_REG, State::S0).as_bool()) {
 		argQ = sigA;
 		subpattern(in_dffe);
 		if (dff) {
@@ -81,7 +86,7 @@ code argQ ffA ffAholdmux ffArstmux ffAholdpol ffArstpol sigA clock clock_pol
 endcode
 
 code argQ ffB ffBholdmux ffBrstmux ffBholdpol ffBrstpol sigB clock clock_pol
-	if (mul->type != \SB_MAC16 || !param(mul, \B_REG).as_bool()) {
+	if (mul->type != \SB_MAC16 || !param(mul, \B_REG, State::S0).as_bool()) {
 		argQ = sigB;
 		subpattern(in_dffe);
 		if (dff) {
@@ -104,7 +109,7 @@ endcode
 code argD ffFJKG sigH clock clock_pol
 	if (nusers(sigH) == 2 &&
 			(mul->type != \SB_MAC16 ||
-			 (!param(mul, \TOP_8x8_MULT_REG).as_bool() && !param(mul, \BOT_8x8_MULT_REG).as_bool() && !param(mul, \PIPELINE_16x16_MULT_REG1).as_bool() && !param(mul, \PIPELINE_16x16_MULT_REG1).as_bool()))) {
+			 (!param(mul, \TOP_8x8_MULT_REG, State::S0).as_bool() && !param(mul, \BOT_8x8_MULT_REG, State::S0).as_bool() && !param(mul, \PIPELINE_16x16_MULT_REG1, State::S0).as_bool() && !param(mul, \PIPELINE_16x16_MULT_REG1, State::S0).as_bool()))) {
 		argD = sigH;
 		subpattern(out_dffe);
 		if (dff) {
@@ -143,7 +148,7 @@ endcode
 
 code argD ffH sigH sigO clock clock_pol
 	if (ffFJKG && nusers(sigH) == 2 &&
-			(mul->type != \SB_MAC16 || !param(mul, \PIPELINE_16x16_MULT_REG2).as_bool())) {
+			(mul->type != \SB_MAC16 || !param(mul, \PIPELINE_16x16_MULT_REG2, State::S0).as_bool())) {
 		argD = sigH;
 		subpattern(out_dffe);
 		if (dff) {
@@ -174,7 +179,7 @@ reject_ffH:		;
 endcode
 
 match add
-	if mul->type != \SB_MAC16 || (param(mul, \TOPOUTPUT_SELECT).as_int() == 3 && param(mul, \BOTOUTPUT_SELECT).as_int() == 3)
+	if mul->type != \SB_MAC16 || (param(mul, \TOPOUTPUT_SELECT, State::S0).as_int() == 3 && param(mul, \BOTOUTPUT_SELECT, State::S0).as_int() == 3)
 
 	select add->type.in($add)
 	choice <IdString> AB {\A, \B}
@@ -200,7 +205,7 @@ code sigCD sigO cd_signed
 		if ((actual_acc_width > actual_mul_width) && (natural_mul_width > actual_mul_width))
 			reject;
 		// If accumulator, check adder width and signedness
-		if (sigCD == sigH && (actual_acc_width != actual_mul_width) && (param(mul, \A_SIGNED).as_bool() != param(add, \A_SIGNED).as_bool()))
+		if (sigCD == sigH && (actual_acc_width != actual_mul_width) && (param(mul, \A_SIGNED, State::S0).as_bool() != param(add, \A_SIGNED).as_bool()))
 			reject;
 
 		sigO = port(add, \Y);
@@ -275,7 +280,7 @@ endcode
 
 code argQ ffCD ffCDholdmux ffCDholdpol ffCDrstpol sigCD clock clock_pol
 	if (!sigCD.empty() && sigCD != sigO &&
-			(mul->type != \SB_MAC16 || (!param(mul, \C_REG).as_bool() && !param(mul, \D_REG).as_bool()))) {
+			(mul->type != \SB_MAC16 || (!param(mul, \C_REG, State::S0).as_bool() && !param(mul, \D_REG, State::S0).as_bool()))) {
 		argQ = sigCD;
 		subpattern(in_dffe);
 		if (dff) {
@@ -328,6 +333,8 @@ arg argD argQ clock clock_pol
 
 code
 	dff = nullptr;
+	if (argQ.empty())
+		reject;
 	for (auto c : argQ.chunks()) {
 		if (!c.wire)
 			reject;
diff --git a/passes/pmgen/ice40_wrapcarry.cc b/passes/pmgen/ice40_wrapcarry.cc
index 69ef3cd82..6e154147f 100644
--- a/passes/pmgen/ice40_wrapcarry.cc
+++ b/passes/pmgen/ice40_wrapcarry.cc
@@ -50,6 +50,14 @@ void create_ice40_wrapcarry(ice40_wrapcarry_pm &pm)
 	cell->setPort("\\O", st.lut->getPort("\\O"));
 	cell->setParam("\\LUT", st.lut->getParam("\\LUT_INIT"));
 
+	for (const auto &a : st.carry->attributes)
+		cell->attributes[stringf("\\SB_CARRY.%s", a.first.c_str())] = a.second;
+	for (const auto &a : st.lut->attributes)
+		cell->attributes[stringf("\\SB_LUT4.%s", a.first.c_str())] = a.second;
+	cell->attributes[ID(SB_LUT4.name)] = Const(st.lut->name.str());
+	if (st.carry->get_bool_attribute(ID::keep) || st.lut->get_bool_attribute(ID::keep))
+		cell->attributes[ID::keep] = true;
+
 	pm.autoremove(st.carry);
 	pm.autoremove(st.lut);
 }
@@ -62,28 +70,79 @@ struct Ice40WrapCarryPass : public Pass {
 		log("\n");
 		log("    ice40_wrapcarry [selection]\n");
 		log("\n");
-		log("Wrap manually instantiated SB_CARRY cells, along with their associated SB_LUTs,\n");
+		log("Wrap manually instantiated SB_CARRY cells, along with their associated SB_LUT4s,\n");
 		log("into an internal $__ICE40_CARRY_WRAPPER cell for preservation across technology\n");
-		log("mapping.");
+		log("mapping.\n");
+		log("\n");
+		log("Attributes on both cells will have their names prefixed with 'SB_CARRY.' or\n");
+		log("'SB_LUT4.' and attached to the wrapping cell.\n");
+		log("A (* keep *) attribute on either cell will be logically OR-ed together.\n");
+		log("\n");
+		log("    -unwrap\n");
+		log("        unwrap $__ICE40_CARRY_WRAPPER cells back into SB_CARRYs and SB_LUT4s,\n");
+		log("        including restoring their attributes.\n");
 		log("\n");
 	}
 	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
 	{
+		bool unwrap = false;
+
 		log_header(design, "Executing ICE40_WRAPCARRY pass (wrap carries).\n");
 
 		size_t argidx;
 		for (argidx = 1; argidx < args.size(); argidx++)
 		{
-			// if (args[argidx] == "-singleton") {
-			// 	singleton_mode = true;
-			// 	continue;
-			// }
+			if (args[argidx] == "-unwrap") {
+				unwrap = true;
+				continue;
+			}
 			break;
 		}
 		extra_args(args, argidx, design);
 
-		for (auto module : design->selected_modules())
-			ice40_wrapcarry_pm(module, module->selected_cells()).run_ice40_wrapcarry(create_ice40_wrapcarry);
+		for (auto module : design->selected_modules()) {
+			if (!unwrap)
+				ice40_wrapcarry_pm(module, module->selected_cells()).run_ice40_wrapcarry(create_ice40_wrapcarry);
+			else {
+				for (auto cell : module->selected_cells()) {
+					if (cell->type != ID($__ICE40_CARRY_WRAPPER))
+						continue;
+
+					auto carry = module->addCell(NEW_ID, ID(SB_CARRY));
+					carry->setPort(ID(I0), cell->getPort(ID(A)));
+					carry->setPort(ID(I1), cell->getPort(ID(B)));
+					carry->setPort(ID(CI), cell->getPort(ID(CI)));
+					carry->setPort(ID(CO), cell->getPort(ID(CO)));
+					module->swap_names(carry, cell);
+					auto lut_name = cell->attributes.at(ID(SB_LUT4.name), Const(NEW_ID.str())).decode_string();
+					auto lut = module->addCell(lut_name, ID($lut));
+					lut->setParam(ID(WIDTH), 4);
+					lut->setParam(ID(LUT), cell->getParam(ID(LUT)));
+					lut->setPort(ID(A), {cell->getPort(ID(I0)), cell->getPort(ID(A)), cell->getPort(ID(B)), cell->getPort(ID(I3)) });
+					lut->setPort(ID(Y), cell->getPort(ID(O)));
+
+					Const src;
+					for (const auto &a : cell->attributes)
+						if (a.first.begins_with("\\SB_CARRY.\\"))
+							carry->attributes[a.first.c_str() + strlen("\\SB_CARRY.")] = a.second;
+						else if (a.first.begins_with("\\SB_LUT4.\\"))
+							lut->attributes[a.first.c_str() + strlen("\\SB_LUT4.")] = a.second;
+						else if (a.first == ID(src))
+							src = a.second;
+						else if (a.first.in(ID(SB_LUT4.name), ID::keep, ID(module_not_derived)))
+							continue;
+						else
+							log_abort();
+
+					if (!src.empty()) {
+						carry->attributes.insert(std::make_pair(ID(src), src));
+						lut->attributes.insert(std::make_pair(ID(src), src));
+					}
+
+					module->remove(cell);
+				}
+			}
+		}
 	}
 } Ice40WrapCarryPass;
 
diff --git a/passes/pmgen/xilinx_dsp.cc b/passes/pmgen/xilinx_dsp.cc
index 054e123e4..81c3c57c4 100644
--- a/passes/pmgen/xilinx_dsp.cc
+++ b/passes/pmgen/xilinx_dsp.cc
@@ -26,6 +26,7 @@ USING_YOSYS_NAMESPACE
 PRIVATE_NAMESPACE_BEGIN
 
 #include "passes/pmgen/xilinx_dsp_pm.h"
+#include "passes/pmgen/xilinx_dsp48a_pm.h"
 #include "passes/pmgen/xilinx_dsp_CREG_pm.h"
 #include "passes/pmgen/xilinx_dsp_cascade_pm.h"
 
@@ -487,6 +488,190 @@ void xilinx_dsp_pack(xilinx_dsp_pm &pm)
 	pm.blacklist(cell);
 }
 
+void xilinx_dsp48a_pack(xilinx_dsp48a_pm &pm)
+{
+	auto &st = pm.st_xilinx_dsp48a_pack;
+
+	log("Analysing %s.%s for Xilinx DSP48A/DSP48A1 packing.\n", log_id(pm.module), log_id(st.dsp));
+
+	log_debug("preAdd:     %s\n", log_id(st.preAdd, "--"));
+	log_debug("ffA1:       %s %s %s\n", log_id(st.ffA1, "--"), log_id(st.ffA1cemux, "--"), log_id(st.ffA1rstmux, "--"));
+	log_debug("ffA0:       %s %s %s\n", log_id(st.ffA0, "--"), log_id(st.ffA0cemux, "--"), log_id(st.ffA0rstmux, "--"));
+	log_debug("ffB1:       %s %s %s\n", log_id(st.ffB1, "--"), log_id(st.ffB1cemux, "--"), log_id(st.ffB1rstmux, "--"));
+	log_debug("ffB0:       %s %s %s\n", log_id(st.ffB0, "--"), log_id(st.ffB0cemux, "--"), log_id(st.ffB0rstmux, "--"));
+	log_debug("ffD:        %s %s %s\n", log_id(st.ffD, "--"), log_id(st.ffDcemux, "--"), log_id(st.ffDrstmux, "--"));
+	log_debug("dsp:        %s\n", log_id(st.dsp, "--"));
+	log_debug("ffM:        %s %s %s\n", log_id(st.ffM, "--"), log_id(st.ffMcemux, "--"), log_id(st.ffMrstmux, "--"));
+	log_debug("postAdd:    %s\n", log_id(st.postAdd, "--"));
+	log_debug("postAddMux: %s\n", log_id(st.postAddMux, "--"));
+	log_debug("ffP:        %s %s %s\n", log_id(st.ffP, "--"), log_id(st.ffPcemux, "--"), log_id(st.ffPrstmux, "--"));
+
+	Cell *cell = st.dsp;
+	SigSpec &opmode = cell->connections_.at(ID(OPMODE));
+
+	if (st.preAdd) {
+		log("  preadder %s (%s)\n", log_id(st.preAdd), log_id(st.preAdd->type));
+		bool D_SIGNED = st.preAdd->getParam(ID(A_SIGNED)).as_bool();
+		bool B_SIGNED = st.preAdd->getParam(ID(B_SIGNED)).as_bool();
+		st.sigB.extend_u0(18, B_SIGNED);
+		st.sigD.extend_u0(18, D_SIGNED);
+		cell->setPort(ID(B), st.sigB);
+		cell->setPort(ID(D), st.sigD);
+		opmode[4] = State::S1;
+		if (st.preAdd->type == ID($add))
+			opmode[6] = State::S0;
+		else if (st.preAdd->type == ID($sub))
+			opmode[6] = State::S1;
+		else
+			log_assert(!"strange pre-adder type");
+
+		pm.autoremove(st.preAdd);
+	}
+	if (st.postAdd) {
+		log("  postadder %s (%s)\n", log_id(st.postAdd), log_id(st.postAdd->type));
+
+		if (st.postAddMux) {
+			log_assert(st.ffP);
+			opmode[2] = st.postAddMux->getPort(ID(S));
+			pm.autoremove(st.postAddMux);
+		}
+		else if (st.ffP && st.sigC == st.sigP)
+			opmode[2] = State::S0;
+		else
+			opmode[2] = State::S1;
+		opmode[3] = State::S1;
+
+		if (opmode[2] != State::S0) {
+			if (st.postAddMuxAB == ID(A))
+				st.sigC.extend_u0(48, st.postAdd->getParam(ID(B_SIGNED)).as_bool());
+			else
+				st.sigC.extend_u0(48, st.postAdd->getParam(ID(A_SIGNED)).as_bool());
+			cell->setPort(ID(C), st.sigC);
+		}
+
+		pm.autoremove(st.postAdd);
+	}
+
+	if (st.clock != SigBit())
+	{
+		cell->setPort(ID(CLK), st.clock);
+
+		auto f = [&pm,cell](SigSpec &A, Cell* ff, Cell* cemux, bool cepol, IdString ceport, Cell* rstmux, bool rstpol, IdString rstport) {
+			SigSpec D = ff->getPort(ID(D));
+			SigSpec Q = pm.sigmap(ff->getPort(ID(Q)));
+			if (!A.empty())
+				A.replace(Q, D);
+			if (rstmux) {
+				SigSpec Y = rstmux->getPort(ID(Y));
+				SigSpec AB = rstmux->getPort(rstpol ? ID(A) : ID(B));
+				if (!A.empty())
+					A.replace(Y, AB);
+				if (rstport != IdString()) {
+					SigSpec S = rstmux->getPort(ID(S));
+					cell->setPort(rstport, rstpol ? S : pm.module->Not(NEW_ID, S));
+				}
+			}
+			else if (rstport != IdString())
+				cell->setPort(rstport, State::S0);
+			if (cemux) {
+				SigSpec Y = cemux->getPort(ID(Y));
+				SigSpec BA = cemux->getPort(cepol ? ID(B) : ID(A));
+				SigSpec S = cemux->getPort(ID(S));
+				if (!A.empty())
+					A.replace(Y, BA);
+				cell->setPort(ceport, cepol ? S : pm.module->Not(NEW_ID, S));
+			}
+			else
+				cell->setPort(ceport, State::S1);
+
+			for (auto c : Q.chunks()) {
+				auto it = c.wire->attributes.find(ID(init));
+				if (it == c.wire->attributes.end())
+					continue;
+				for (int i = c.offset; i < c.offset+c.width; i++) {
+					log_assert(it->second[i] == State::S0 || it->second[i] == State::Sx);
+					it->second[i] = State::Sx;
+				}
+			}
+		};
+
+		if (st.ffA0 || st.ffA1) {
+			SigSpec A = cell->getPort(ID(A));
+			if (st.ffA1) {
+				f(A, st.ffA1, st.ffA1cemux, st.ffAcepol, ID(CEA), st.ffA1rstmux, st.ffArstpol, ID(RSTA));
+				cell->setParam(ID(A1REG), 1);
+			}
+			if (st.ffA0) {
+				f(A, st.ffA0, st.ffA0cemux, st.ffAcepol, ID(CEA), st.ffA0rstmux, st.ffArstpol, ID(RSTA));
+				cell->setParam(ID(A0REG), 1);
+			}
+			pm.add_siguser(A, cell);
+			cell->setPort(ID(A), A);
+		}
+		if (st.ffB0 || st.ffB1) {
+			SigSpec B = cell->getPort(ID(B));
+			if (st.ffB1) {
+				f(B, st.ffB1, st.ffB1cemux, st.ffBcepol, ID(CEB), st.ffB1rstmux, st.ffBrstpol, ID(RSTB));
+				cell->setParam(ID(B1REG), 1);
+			}
+			if (st.ffB0) {
+				f(B, st.ffB0, st.ffB0cemux, st.ffBcepol, ID(CEB), st.ffB0rstmux, st.ffBrstpol, ID(RSTB));
+				cell->setParam(ID(B0REG), 1);
+			}
+			pm.add_siguser(B, cell);
+			cell->setPort(ID(B), B);
+		}
+		if (st.ffD) {
+			SigSpec D = cell->getPort(ID(D));
+			f(D, st.ffD, st.ffDcemux, st.ffDcepol, ID(CED), st.ffDrstmux, st.ffDrstpol, ID(RSTD));
+			pm.add_siguser(D, cell);
+			cell->setPort(ID(D), D);
+			cell->setParam(ID(DREG), 1);
+		}
+		if (st.ffM) {
+			SigSpec M; // unused
+			f(M, st.ffM, st.ffMcemux, st.ffMcepol, ID(CEM), st.ffMrstmux, st.ffMrstpol, ID(RSTM));
+			st.ffM->connections_.at(ID(Q)).replace(st.sigM, pm.module->addWire(NEW_ID, GetSize(st.sigM)));
+			cell->setParam(ID(MREG), State::S1);
+		}
+		if (st.ffP) {
+			SigSpec P; // unused
+			f(P, st.ffP, st.ffPcemux, st.ffPcepol, ID(CEP), st.ffPrstmux, st.ffPrstpol, ID(RSTP));
+			st.ffP->connections_.at(ID(Q)).replace(st.sigP, pm.module->addWire(NEW_ID, GetSize(st.sigP)));
+			cell->setParam(ID(PREG), State::S1);
+		}
+
+		log("  clock: %s (%s)", log_signal(st.clock), "posedge");
+
+		if (st.ffA0)
+			log(" ffA0:%s", log_id(st.ffA0));
+		if (st.ffA1)
+			log(" ffA1:%s", log_id(st.ffA1));
+
+		if (st.ffB0)
+			log(" ffB0:%s", log_id(st.ffB0));
+		if (st.ffB1)
+			log(" ffB1:%s", log_id(st.ffB1));
+
+		if (st.ffD)
+			log(" ffD:%s", log_id(st.ffD));
+
+		if (st.ffM)
+			log(" ffM:%s", log_id(st.ffM));
+
+		if (st.ffP)
+			log(" ffP:%s", log_id(st.ffP));
+	}
+	log("\n");
+
+	SigSpec P = st.sigP;
+	if (GetSize(P) < 48)
+		P.append(pm.module->addWire(NEW_ID, 48-GetSize(P)));
+	cell->setPort(ID(P), P);
+
+	pm.blacklist(cell);
+}
+
 void xilinx_dsp_packC(xilinx_dsp_CREG_pm &pm)
 {
 	auto &st = pm.st_xilinx_dsp_packC;
@@ -592,33 +777,48 @@ struct XilinxDspPass : public Pass {
 		log("P output implementing the operation \"(P >= <power-of-2>)\" will be transformed\n");
 		log("into using the DSP48E1's pattern detector feature for overflow detection.\n");
 		log("\n");
+		log("    -family {xcup|xcu|xc7|xc6v|xc5v|xc4v|xc6s|xc3sda}\n");
+		log("        select the family to target\n");
+		log("        default: xc7\n");
+		log("\n");
 	}
 	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
 	{
 		log_header(design, "Executing XILINX_DSP pass (pack resources into DSPs).\n");
 
+		std::string family = "xc7";
 		size_t argidx;
 		for (argidx = 1; argidx < args.size(); argidx++)
 		{
-			// if (args[argidx] == "-singleton") {
-			// 	singleton_mode = true;
-			// 	continue;
-			// }
+			if ((args[argidx] == "-family" || args[argidx] == "-arch") && argidx+1 < args.size()) {
+				family = args[++argidx];
+				continue;
+			}
 			break;
 		}
 		extra_args(args, argidx, design);
 
+		// Don't bother distinguishing between those.
+		if (family == "xc6v")
+			family = "xc7";
+		if (family == "xcup")
+			family = "xcu";
+
 		for (auto module : design->selected_modules()) {
 			// Experimental feature: pack $add/$sub cells with
 			//   (* use_dsp48="simd" *) into DSP48E1's using its
 			//   SIMD feature
-			xilinx_simd_pack(module, module->selected_cells());
+			if (family == "xc7")
+				xilinx_simd_pack(module, module->selected_cells());
 
 			// Match for all features ([ABDMP][12]?REG, pre-adder,
 			// post-adder, pattern detector, etc.) except for CREG
-			{
+			if (family == "xc7") {
 				xilinx_dsp_pm pm(module, module->selected_cells());
 				pm.run_xilinx_dsp_pack(xilinx_dsp_pack);
+			} else if (family == "xc6s" || family == "xc3sda") {
+				xilinx_dsp48a_pm pm(module, module->selected_cells());
+				pm.run_xilinx_dsp48a_pack(xilinx_dsp48a_pack);
 			}
 			// Separating out CREG packing is necessary since there
 			//   is no guarantee that the cell ordering corresponds
diff --git a/passes/pmgen/xilinx_dsp.pmg b/passes/pmgen/xilinx_dsp.pmg
index 0ba529011..af47ab111 100644
--- a/passes/pmgen/xilinx_dsp.pmg
+++ b/passes/pmgen/xilinx_dsp.pmg
@@ -120,7 +120,7 @@ endcode
 //      reset functionality, using a subpattern discussed above)
 //     If matched, treat 'A' input as input of ADREG
 code argQ ffAD ffADcemux ffADrstmux ffADcepol ffADrstpol sigA clock
-	if (param(dsp, \ADREG).as_int() == 0) {
+	if (param(dsp, \ADREG, 1).as_int() == 0) {
 		argQ = sigA;
 		subpattern(in_dffe);
 		if (dff) {
@@ -176,7 +176,7 @@ code argQ ffAD ffADcemux ffADrstmux ffADcepol ffADrstpol sigA clock ffA2 ffA2cem
 	// Only search for ffA2 if there was a pre-adder
 	//   (otherwise ffA2 would have been matched as ffAD)
 	if (preAdd) {
-		if (param(dsp, \AREG).as_int() == 0) {
+		if (param(dsp, \AREG, 1).as_int() == 0) {
 			argQ = sigA;
 			subpattern(in_dffe);
 			if (dff) {
@@ -237,7 +237,7 @@ endcode
 // (5) Match 'B' input for B2REG
 //     If B2REG, then match 'B' input for B1REG
 code argQ ffB2 ffB2cemux ffB2rstmux ffB2cepol ffBrstpol sigB clock ffB1 ffB1cemux ffB1rstmux ffB1cepol
-	if (param(dsp, \BREG).as_int() == 0) {
+	if (param(dsp, \BREG, 1).as_int() == 0) {
 		argQ = sigB;
 		subpattern(in_dffe);
 		if (dff) {
@@ -287,7 +287,7 @@ endcode
 
 // (6) Match 'D' input for DREG
 code argQ ffD ffDcemux ffDrstmux ffDcepol ffDrstpol sigD clock
-	if (param(dsp, \DREG).as_int() == 0) {
+	if (param(dsp, \DREG, 1).as_int() == 0) {
 		argQ = sigD;
 		subpattern(in_dffe);
 		if (dff) {
@@ -308,7 +308,7 @@ endcode
 
 // (7) Match 'P' output that exclusively drives an MREG
 code argD ffM ffMcemux ffMrstmux ffMcepol ffMrstpol sigM sigP clock
-	if (param(dsp, \MREG).as_int() == 0 && nusers(sigM) == 2) {
+	if (param(dsp, \MREG, 1).as_int() == 0 && nusers(sigM) == 2) {
 		argD = sigM;
 		subpattern(out_dffe);
 		if (dff) {
@@ -335,7 +335,7 @@ endcode
 //      recognised in xilinx_dsp.cc).
 match postAdd
 	// Ensure that Z mux is not already used
-	if port(dsp, \OPMODE, SigSpec()).extract(4,3).is_fully_zero()
+	if port(dsp, \OPMODE, SigSpec(0, 7)).extract(4,3).is_fully_zero()
 
 	select postAdd->type.in($add)
 	select GetSize(port(postAdd, \Y)) <= 48
@@ -347,9 +347,9 @@ match postAdd
 	index <SigBit> port(postAdd, AB)[0] === sigP[0]
 	filter GetSize(port(postAdd, AB)) >= GetSize(sigP)
 	filter port(postAdd, AB).extract(0, GetSize(sigP)) == sigP
-	// Check that remainder of AB is a sign-extension
-	define <bool> AB_SIGNED (param(postAdd, AB == \A ? \A_SIGNED : \B_SIGNED).as_bool())
-	filter port(postAdd, AB).extract_end(GetSize(sigP)) == SigSpec(AB_SIGNED ? sigP[GetSize(sigP)-1] : State::S0, GetSize(port(postAdd, AB))-GetSize(sigP))
+	// Check that remainder of AB is a sign- or zero-extension
+	filter port(postAdd, AB).extract_end(GetSize(sigP)) == SigSpec(sigP[GetSize(sigP)-1], GetSize(port(postAdd, AB))-GetSize(sigP)) || port(postAdd, AB).extract_end(GetSize(sigP)) == SigSpec(State::S0, GetSize(port(postAdd, AB))-GetSize(sigP))
+
 	set postAddAB AB
 	optional
 endmatch
@@ -363,7 +363,7 @@ endcode
 
 // (9) Match 'P' output that exclusively drives a PREG
 code argD ffP ffPcemux ffPrstmux ffPcepol ffPrstpol sigP clock
-	if (param(dsp, \PREG).as_int() == 0) {
+	if (param(dsp, \PREG, 1).as_int() == 0) {
 		int users = 2;
 		// If ffMcemux and no postAdd new-value net must have three users: ffMcemux, ffM and ffPcemux
 		if (ffMcemux && !postAdd) users++;
@@ -460,7 +460,7 @@ arg argD argQ clock
 
 code
 	dff = nullptr;
-	if (GetSize(argQ) == 0)
+	if (argQ.empty())
 		reject;
 	for (const auto &c : argQ.chunks()) {
 		// Abandon matches when 'Q' is a constant
diff --git a/passes/pmgen/xilinx_dsp48a.pmg b/passes/pmgen/xilinx_dsp48a.pmg
new file mode 100644
index 000000000..16f5e598d
--- /dev/null
+++ b/passes/pmgen/xilinx_dsp48a.pmg
@@ -0,0 +1,673 @@
+// This file describes the main pattern matcher setup (of three total) that
+//   forms the `xilinx_dsp` pass described in xilinx_dsp.cc - version for
+//   DSP48A/DSP48A1 (Spartan 3A DSP, Spartan 6).
+// At a high level, it works as follows:
+//   ( 1) Starting from a DSP48A/DSP48A1 cell
+//   ( 2) Match the driver of the 'B' input to a possible $dff cell (B1REG)
+//        (attached to at most two $mux cells that implement clock-enable or
+//         reset functionality, using a subpattern discussed below)
+//        If B1REG matched, treat 'B' input as input of B1REG
+//   ( 3) Match the driver of the 'B' and 'D' inputs for a possible $add cell
+//       (pre-adder)
+//   ( 4) Match 'B' input for B0REG
+//   ( 5) Match 'A' input for A1REG
+//        If A1REG, then match 'A' input for A0REG
+//   ( 6) Match 'D' input for DREG
+//   ( 7) Match 'P' output that exclusively drives an MREG
+//   ( 8) Match 'P' output that exclusively drives one of two inputs to an $add
+//        cell (post-adder).
+//        The other input to the adder is assumed to come in from the 'C' input
+//        (note: 'P' -> 'C' connections that exist for accumulators are
+//         recognised in xilinx_dsp.cc).
+//   ( 9) Match 'P' output that exclusively drives a PREG
+//   (10) If post-adder and PREG both present, match for a $mux cell driving
+//        the 'C' input, where one of the $mux's inputs is the PREG output.
+//        This indicates an accumulator situation, and one where a $mux exists
+//        to override the accumulated value:
+//             +--------------------------------+
+//             |   ____                         |
+//             +--|    \                        |
+//                |$mux|-+                      |
+//         'C' ---|____/ |                      |
+//                       | /-------\   +----+   |
+//            +----+     +-| post- |___|PREG|---+ 'P'
+//            |MREG|------ | adder |   +----+
+//            +----+       \-------/
+// Notes: see the notes in xilinx_dsp.pmg
+
+pattern xilinx_dsp48a_pack
+
+state <SigBit> clock
+state <SigSpec> sigA sigB sigC sigD sigM sigP
+state <IdString> postAddAB postAddMuxAB
+state <bool> ffAcepol ffBcepol ffDcepol ffMcepol ffPcepol
+state <bool> ffArstpol ffBrstpol ffDrstpol ffMrstpol ffPrstpol
+state <Cell*> ffA0 ffA0cemux ffA0rstmux ffA1 ffA1cemux ffA1rstmux
+state <Cell*> ffB0 ffB0cemux ffB0rstmux ffB1 ffB1cemux ffB1rstmux
+state <Cell*> ffD ffDcemux ffDrstmux ffM ffMcemux ffMrstmux ffP ffPcemux ffPrstmux
+
+// Variables used for subpatterns
+state <SigSpec> argQ argD
+state <bool> ffcepol ffrstpol
+state <int> ffoffset
+udata <SigSpec> dffD dffQ
+udata <SigBit> dffclock
+udata <Cell*> dff dffcemux dffrstmux
+udata <bool> dffcepol dffrstpol
+
+// (1) Starting from a DSP48A/DSP48A1 cell
+match dsp
+	select dsp->type.in(\DSP48A, \DSP48A1)
+endmatch
+
+code sigA sigB sigC sigD sigM clock
+	auto unextend = [](const SigSpec &sig) {
+		int i;
+		for (i = GetSize(sig)-1; i > 0; i--)
+			if (sig[i] != sig[i-1])
+				break;
+		// Do not remove non-const sign bit
+		if (sig[i].wire)
+			++i;
+		return sig.extract(0, i);
+	};
+	sigA = unextend(port(dsp, \A));
+	sigB = unextend(port(dsp, \B));
+
+	sigC = port(dsp, \C, SigSpec());
+	sigD = port(dsp, \D, SigSpec());
+
+	SigSpec P = port(dsp, \P);
+	// Only care about those bits that are used
+	int i;
+	for (i = GetSize(P)-1; i >= 0; i--)
+		if (nusers(P[i]) > 1)
+			break;
+	i++;
+	log_assert(nusers(P.extract_end(i)) <= 1);
+	// This sigM could have no users if downstream sinks (e.g. $add) is
+	//   narrower than $mul result, for example
+	if (i == 0)
+		reject;
+	sigM = P.extract(0, i);
+
+	clock = port(dsp, \CLK, SigBit());
+endcode
+
+// (2) Match the driver of the 'B' input to a possible $dff cell (B1REG)
+//     (attached to at most two $mux cells that implement clock-enable or
+//      reset functionality, using a subpattern discussed above)
+//     If matched, treat 'B' input as input of B1REG
+code argQ ffB1 ffB1cemux ffB1rstmux ffBcepol ffBrstpol sigB clock
+	if (param(dsp, \B1REG).as_int() == 0 && param(dsp, \B0REG).as_int() == 0 && port(dsp, \OPMODE, SigSpec()).extract(4, 1).is_fully_zero()) {
+		argQ = sigB;
+		subpattern(in_dffe);
+		if (dff) {
+			ffB1 = dff;
+			clock = dffclock;
+			if (dffrstmux) {
+				ffB1rstmux = dffrstmux;
+				ffBrstpol = dffrstpol;
+			}
+			if (dffcemux) {
+				ffB1cemux = dffcemux;
+				ffBcepol = dffcepol;
+			}
+			sigB = dffD;
+		}
+	}
+endcode
+
+// (3) Match the driver of the 'B' and 'D' inputs for a possible $add cell
+//     (pre-adder)
+match preAdd
+	if sigD.empty() || sigD.is_fully_zero()
+	if param(dsp, \B0REG).as_int() == 0
+	// Ensure that preAdder not already used
+	if port(dsp, \OPMODE, SigSpec()).extract(4, 1).is_fully_zero()
+
+	select preAdd->type.in($add, $sub)
+	// Output has to be 18 bits or less
+	select GetSize(port(preAdd, \Y)) <= 18
+	select nusers(port(preAdd, \Y)) == 2
+	// D port has to be 18 bits or less
+	select GetSize(port(preAdd, \A)) <= 18
+	// B port has to be 18 bits or less
+	select GetSize(port(preAdd, \B)) <= 18
+	index <SigSpec> port(preAdd, \Y) === sigB
+
+	optional
+endmatch
+
+code sigB sigD
+	if (preAdd) {
+		sigD = port(preAdd, \A);
+		sigB = port(preAdd, \B);
+	}
+endcode
+
+// (4) Match 'B' input for B0REG
+code argQ ffB0 ffB0cemux ffB0rstmux ffBcepol ffBrstpol sigB clock
+	if (param(dsp, \B0REG).as_int() == 0) {
+		argQ = sigB;
+		subpattern(in_dffe);
+		if (dff) {
+			if (ffB1) {
+				if ((ffB1rstmux != nullptr) ^ (dffrstmux != nullptr))
+					goto ffB0_end;
+				if ((ffB1cemux != nullptr) ^ (dffcemux != nullptr))
+					goto ffB0_end;
+				if (dffrstmux) {
+					if (ffBrstpol != dffrstpol)
+						goto ffB0_end;
+					if (port(ffB1rstmux, \S) != port(dffrstmux, \S))
+						goto ffB0_end;
+					ffB0rstmux = dffrstmux;
+				}
+				if (dffcemux) {
+					if (ffBcepol != dffcepol)
+						goto ffB0_end;
+					if (port(ffB1cemux, \S) != port(dffcemux, \S))
+						goto ffB0_end;
+					ffB0cemux = dffcemux;
+				}
+			}
+			ffB0 = dff;
+			clock = dffclock;
+			if (dffrstmux) {
+				ffB0rstmux = dffrstmux;
+				ffBrstpol = dffrstpol;
+			}
+			if (dffcemux) {
+				ffB0cemux = dffcemux;
+				ffBcepol = dffcepol;
+			}
+			sigB = dffD;
+		}
+	}
+ffB0_end:
+endcode
+
+// (5) Match 'A' input for A1REG
+//     If A1REG, then match 'A' input for A0REG
+code argQ ffA1 ffA1cemux ffA1rstmux ffAcepol ffArstpol sigA clock ffA0 ffA0cemux ffA0rstmux
+	if (param(dsp, \A0REG).as_int() == 0 && param(dsp, \A1REG).as_int() == 0) {
+		argQ = sigA;
+		subpattern(in_dffe);
+		if (dff) {
+			ffA1 = dff;
+			clock = dffclock;
+			if (dffrstmux) {
+				ffA1rstmux = dffrstmux;
+				ffArstpol = dffrstpol;
+			}
+			if (dffcemux) {
+				ffA1cemux = dffcemux;
+				ffAcepol = dffcepol;
+			}
+			sigA = dffD;
+
+			// Now attempt to match A0
+			if (ffA1) {
+				argQ = sigA;
+				subpattern(in_dffe);
+				if (dff) {
+					if ((ffA1rstmux != nullptr) ^ (dffrstmux != nullptr))
+						goto ffA0_end;
+					if ((ffA1cemux != nullptr) ^ (dffcemux != nullptr))
+						goto ffA0_end;
+					if (dffrstmux) {
+						if (ffArstpol != dffrstpol)
+							goto ffA0_end;
+						if (port(ffA1rstmux, \S) != port(dffrstmux, \S))
+							goto ffA0_end;
+						ffA0rstmux = dffrstmux;
+					}
+					if (dffcemux) {
+						if (ffAcepol != dffcepol)
+							goto ffA0_end;
+						if (port(ffA1cemux, \S) != port(dffcemux, \S))
+							goto ffA0_end;
+						ffA0cemux = dffcemux;
+					}
+
+					ffA0 = dff;
+					clock = dffclock;
+
+					if (dffcemux) {
+						ffA0cemux = dffcemux;
+						ffAcepol = dffcepol;
+					}
+					sigA = dffD;
+
+ffA0_end:				;
+				}
+			}
+
+		}
+	}
+endcode
+
+// (6) Match 'D' input for DREG
+code argQ ffD ffDcemux ffDrstmux ffDcepol ffDrstpol sigD clock
+	if (param(dsp, \DREG).as_int() == 0) {
+		argQ = sigD;
+		subpattern(in_dffe);
+		if (dff) {
+			ffD = dff;
+			clock = dffclock;
+			if (dffrstmux) {
+				ffDrstmux = dffrstmux;
+				ffDrstpol = dffrstpol;
+			}
+			if (dffcemux) {
+				ffDcemux = dffcemux;
+				ffDcepol = dffcepol;
+			}
+			sigD = dffD;
+		}
+	}
+endcode
+
+// (7) Match 'P' output that exclusively drives an MREG
+code argD ffM ffMcemux ffMrstmux ffMcepol ffMrstpol sigM sigP clock
+	if (param(dsp, \MREG).as_int() == 0 && nusers(sigM) == 2) {
+		argD = sigM;
+		subpattern(out_dffe);
+		if (dff) {
+			ffM = dff;
+			clock = dffclock;
+			if (dffrstmux) {
+				ffMrstmux = dffrstmux;
+				ffMrstpol = dffrstpol;
+			}
+			if (dffcemux) {
+				ffMcemux = dffcemux;
+				ffMcepol = dffcepol;
+			}
+			sigM = dffQ;
+		}
+	}
+	sigP = sigM;
+endcode
+
+// (8) Match 'P' output that exclusively drives one of two inputs to an $add
+//     cell (post-adder).
+//     The other input to the adder is assumed to come in from the 'C' input
+//     (note: 'P' -> 'C' connections that exist for accumulators are
+//      recognised in xilinx_dsp.cc).
+match postAdd
+	// Ensure that Z mux is not already used
+	if port(dsp, \OPMODE, SigSpec()).extract(2,2).is_fully_zero()
+
+	select postAdd->type.in($add)
+	select GetSize(port(postAdd, \Y)) <= 48
+	choice <IdString> AB {\A, \B}
+	select nusers(port(postAdd, AB)) <= 3
+	filter ffMcemux || nusers(port(postAdd, AB)) == 2
+	filter !ffMcemux || nusers(port(postAdd, AB)) == 3
+
+	index <SigBit> port(postAdd, AB)[0] === sigP[0]
+	filter GetSize(port(postAdd, AB)) >= GetSize(sigP)
+	filter port(postAdd, AB).extract(0, GetSize(sigP)) == sigP
+	// Check that remainder of AB is a sign- or zero-extension
+	filter port(postAdd, AB).extract_end(GetSize(sigP)) == SigSpec(sigP[GetSize(sigP)-1], GetSize(port(postAdd, AB))-GetSize(sigP)) || port(postAdd, AB).extract_end(GetSize(sigP)) == SigSpec(State::S0, GetSize(port(postAdd, AB))-GetSize(sigP))
+
+	set postAddAB AB
+	optional
+endmatch
+
+code sigC sigP
+	if (postAdd) {
+		sigC = port(postAdd, postAddAB == \A ? \B : \A);
+		sigP = port(postAdd, \Y);
+	}
+endcode
+
+// (9) Match 'P' output that exclusively drives a PREG
+code argD ffP ffPcemux ffPrstmux ffPcepol ffPrstpol sigP clock
+	if (param(dsp, \PREG).as_int() == 0) {
+		int users = 2;
+		// If ffMcemux and no postAdd new-value net must have three users: ffMcemux, ffM and ffPcemux
+		if (ffMcemux && !postAdd) users++;
+		if (nusers(sigP) == users) {
+			argD = sigP;
+			subpattern(out_dffe);
+			if (dff) {
+				ffP = dff;
+				clock = dffclock;
+				if (dffrstmux) {
+					ffPrstmux = dffrstmux;
+					ffPrstpol = dffrstpol;
+				}
+				if (dffcemux) {
+					ffPcemux = dffcemux;
+					ffPcepol = dffcepol;
+				}
+				sigP = dffQ;
+			}
+		}
+	}
+endcode
+
+// (10) If post-adder and PREG both present, match for a $mux cell driving
+//      the 'C' input, where one of the $mux's inputs is the PREG output.
+//      This indicates an accumulator situation, and one where a $mux exists
+//      to override the accumulated value:
+//           +--------------------------------+
+//           |   ____                         |
+//           +--|    \                        |
+//              |$mux|-+                      |
+//       'C' ---|____/ |                      |
+//                     | /-------\   +----+   |
+//          +----+     +-| post- |___|PREG|---+ 'P'
+//          |MREG|------ | adder |   +----+
+//          +----+       \-------/
+match postAddMux
+	if postAdd
+	if ffP
+	select postAddMux->type.in($mux)
+	select nusers(port(postAddMux, \Y)) == 2
+	choice <IdString> AB {\A, \B}
+	index <SigSpec> port(postAddMux, AB) === sigP
+	index <SigSpec> port(postAddMux, \Y) === sigC
+	set postAddMuxAB AB
+	optional
+endmatch
+
+code sigC
+	if (postAddMux)
+		sigC = port(postAddMux, postAddMuxAB == \A ? \B : \A);
+endcode
+
+code
+	accept;
+endcode
+
+// #######################
+
+// Subpattern for matching against input registers, based on knowledge of the
+//   'Q' input. Typically, identifying registers with clock-enable and reset
+//   capability would be a task would be handled by other Yosys passes such as
+//   dff2dffe, but since DSP inference happens much before this, these patterns
+//   have to be manually identified.
+// At a high level:
+//   (1) Starting from a $dff cell that (partially or fully) drives the given
+//       'Q' argument
+//   (2) Match for a $mux cell implementing synchronous reset semantics ---
+//       one that exclusively drives the 'D' input of the $dff, with one of its
+//       $mux inputs being fully zero
+//   (3) Match for a $mux cell implement clock enable semantics --- one that
+//       exclusively drives the 'D' input of the $dff (or the other input of
+//       the reset $mux) and where one of this $mux's inputs is connected to
+//       the 'Q' output of the $dff
+subpattern in_dffe
+arg argD argQ clock
+
+code
+	dff = nullptr;
+	if (GetSize(argQ) == 0)
+		reject;
+	for (const auto &c : argQ.chunks()) {
+		// Abandon matches when 'Q' is a constant
+		if (!c.wire)
+			reject;
+		// Abandon matches when 'Q' has the keep attribute set
+		if (c.wire->get_bool_attribute(\keep))
+			reject;
+		// Abandon matches when 'Q' has a non-zero init attribute set
+		// (not supported by DSP48E1)
+		Const init = c.wire->attributes.at(\init, Const());
+		if (!init.empty())
+			for (auto b : init.extract(c.offset, c.width))
+				if (b != State::Sx && b != State::S0)
+					reject;
+	}
+endcode
+
+// (1) Starting from a $dff cell that (partially or fully) drives the given
+//     'Q' argument
+match ff
+	select ff->type.in($dff)
+	// DSP48E1 does not support clock inversion
+	select param(ff, \CLK_POLARITY).as_bool()
+
+	slice offset GetSize(port(ff, \D))
+	index <SigBit> port(ff, \Q)[offset] === argQ[0]
+
+	// Check that the rest of argQ is present
+	filter GetSize(port(ff, \Q)) >= offset + GetSize(argQ)
+	filter port(ff, \Q).extract(offset, GetSize(argQ)) == argQ
+
+	filter clock == SigBit() || port(ff, \CLK) == clock
+
+	set ffoffset offset
+endmatch
+
+code argQ argD
+	SigSpec Q = port(ff, \Q);
+	dff = ff;
+	dffclock = port(ff, \CLK);
+	dffD = argQ;
+	argD = port(ff, \D);
+	argQ = Q;
+	dffD.replace(argQ, argD);
+	// Only search for ffrstmux if dffD only
+	//   has two (ff, ffrstmux) users
+	if (nusers(dffD) > 2)
+		argD = SigSpec();
+endcode
+
+// (2) Match for a $mux cell implementing synchronous reset semantics ---
+//     exclusively drives the 'D' input of the $dff, with one of the $mux
+//     inputs being fully zero
+match ffrstmux
+	if !argD.empty()
+	select ffrstmux->type.in($mux)
+	index <SigSpec> port(ffrstmux, \Y) === argD
+
+	choice <IdString> BA {\B, \A}
+	// DSP48E1 only supports reset to zero
+	select port(ffrstmux, BA).is_fully_zero()
+
+	define <bool> pol (BA == \B)
+	set ffrstpol pol
+	semioptional
+endmatch
+
+code argD
+	if (ffrstmux) {
+		dffrstmux = ffrstmux;
+		dffrstpol = ffrstpol;
+		argD = port(ffrstmux, ffrstpol ? \A : \B);
+		dffD.replace(port(ffrstmux, \Y), argD);
+
+		// Only search for ffcemux if argQ has at
+		//   least 3 users (ff, <upstream>, ffrstmux) and
+		//   dffD only has two (ff, ffrstmux)
+		if (!(nusers(argQ) >= 3 && nusers(dffD) == 2))
+			argD = SigSpec();
+	}
+	else
+		dffrstmux = nullptr;
+endcode
+
+// (3) Match for a $mux cell implement clock enable semantics --- one that
+//     exclusively drives the 'D' input of the $dff (or the other input of
+//     the reset $mux) and where one of this $mux's inputs is connected to
+//     the 'Q' output of the $dff
+match ffcemux
+	if !argD.empty()
+	select ffcemux->type.in($mux)
+	index <SigSpec> port(ffcemux, \Y) === argD
+	choice <IdString> AB {\A, \B}
+	index <SigSpec> port(ffcemux, AB) === argQ
+	define <bool> pol (AB == \A)
+	set ffcepol pol
+	semioptional
+endmatch
+
+code argD
+	if (ffcemux) {
+		dffcemux = ffcemux;
+		dffcepol = ffcepol;
+		argD = port(ffcemux, ffcepol ? \B : \A);
+		dffD.replace(port(ffcemux, \Y), argD);
+	}
+	else
+		dffcemux = nullptr;
+endcode
+
+// #######################
+
+// Subpattern for matching against output registers, based on knowledge of the
+//   'D' input.
+// At a high level:
+//   (1) Starting from an optional $mux cell that implements clock enable
+//       semantics --- one where the given 'D' argument (partially or fully)
+//       drives one of its two inputs
+//   (2) Starting from, or continuing onto, another optional $mux cell that
+//       implements synchronous reset semantics --- one where the given 'D'
+//       argument (or the clock enable $mux output) drives one of its two inputs
+//       and where the other input is fully zero
+//   (3) Match for a $dff cell (whose 'D' input is the 'D' argument, or the
+//       output of the previous clock enable or reset $mux cells)
+subpattern out_dffe
+arg argD argQ clock
+
+code
+	dff = nullptr;
+	for (auto c : argD.chunks())
+		// Abandon matches when 'D' has the keep attribute set
+		if (c.wire->get_bool_attribute(\keep))
+			reject;
+endcode
+
+// (1) Starting from an optional $mux cell that implements clock enable
+//     semantics --- one where the given 'D' argument (partially or fully)
+//     drives one of its two inputs
+match ffcemux
+	select ffcemux->type.in($mux)
+	// ffcemux output must have two users: ffcemux and ff.D
+	select nusers(port(ffcemux, \Y)) == 2
+
+	choice <IdString> AB {\A, \B}
+	// keep-last-value net must have at least three users: ffcemux, ff, downstream sink(s)
+	select nusers(port(ffcemux, AB)) >= 3
+
+	slice offset GetSize(port(ffcemux, \Y))
+	define <IdString> BA (AB == \A ? \B : \A)
+	index <SigBit> port(ffcemux, BA)[offset] === argD[0]
+
+	// Check that the rest of argD is present
+	filter GetSize(port(ffcemux, BA)) >= offset + GetSize(argD)
+	filter port(ffcemux, BA).extract(offset, GetSize(argD)) == argD
+
+	set ffoffset offset
+	define <bool> pol (AB == \A)
+	set ffcepol pol
+
+	semioptional
+endmatch
+
+code argD argQ
+	dffcemux = ffcemux;
+	if (ffcemux) {
+		SigSpec BA = port(ffcemux, ffcepol ? \B : \A);
+		SigSpec Y = port(ffcemux, \Y);
+		argQ = argD;
+		argD.replace(BA, Y);
+		argQ.replace(BA, port(ffcemux, ffcepol ? \A : \B));
+
+		dffcemux = ffcemux;
+		dffcepol = ffcepol;
+	}
+endcode
+
+// (2) Starting from, or continuing onto, another optional $mux cell that
+//     implements synchronous reset semantics --- one where the given 'D'
+//     argument (or the clock enable $mux output) drives one of its two inputs
+//     and where the other input is fully zero
+match ffrstmux
+	select ffrstmux->type.in($mux)
+	// ffrstmux output must have two users: ffrstmux and ff.D
+	select nusers(port(ffrstmux, \Y)) == 2
+
+	choice <IdString> BA {\B, \A}
+	// DSP48E1 only supports reset to zero
+	select port(ffrstmux, BA).is_fully_zero()
+
+	slice offset GetSize(port(ffrstmux, \Y))
+	define <IdString> AB (BA == \B ? \A : \B)
+	index <SigBit> port(ffrstmux, AB)[offset] === argD[0]
+
+	// Check that offset is consistent
+	filter !ffcemux || ffoffset == offset
+	// Check that the rest of argD is present
+	filter GetSize(port(ffrstmux, AB)) >= offset + GetSize(argD)
+	filter port(ffrstmux, AB).extract(offset, GetSize(argD)) == argD
+
+	set ffoffset offset
+	define <bool> pol (AB == \A)
+	set ffrstpol pol
+
+	semioptional
+endmatch
+
+code argD argQ
+	dffrstmux = ffrstmux;
+	if (ffrstmux) {
+		SigSpec AB = port(ffrstmux, ffrstpol ? \A : \B);
+		SigSpec Y = port(ffrstmux, \Y);
+		argD.replace(AB, Y);
+
+		dffrstmux = ffrstmux;
+		dffrstpol = ffrstpol;
+	}
+endcode
+
+// (3) Match for a $dff cell (whose 'D' input is the 'D' argument, or the
+//     output of the previous clock enable or reset $mux cells)
+match ff
+	select ff->type.in($dff)
+	// DSP48E1 does not support clock inversion
+	select param(ff, \CLK_POLARITY).as_bool()
+
+	slice offset GetSize(port(ff, \D))
+	index <SigBit> port(ff, \D)[offset] === argD[0]
+
+	// Check that offset is consistent
+	filter (!ffcemux && !ffrstmux) || ffoffset == offset
+	// Check that the rest of argD is present
+	filter GetSize(port(ff, \D)) >= offset + GetSize(argD)
+	filter port(ff, \D).extract(offset, GetSize(argD)) == argD
+	// Check that FF.Q is connected to CE-mux
+	filter !ffcemux || port(ff, \Q).extract(offset, GetSize(argQ)) == argQ
+
+	filter clock == SigBit() || port(ff, \CLK) == clock
+
+	set ffoffset offset
+endmatch
+
+code argQ
+	SigSpec D = port(ff, \D);
+	SigSpec Q = port(ff, \Q);
+	if (!ffcemux) {
+		argQ = argD;
+		argQ.replace(D, Q);
+	}
+
+	// Abandon matches when 'Q' has a non-zero init attribute set
+	// (not supported by DSP48E1)
+	for (auto c : argQ.chunks()) {
+		Const init = c.wire->attributes.at(\init, Const());
+		if (!init.empty())
+			for (auto b : init.extract(c.offset, c.width))
+				if (b != State::Sx && b != State::S0)
+					reject;
+	}
+
+	dff = ff;
+	dffQ = argQ;
+	dffclock = port(ff, \CLK);
+endcode
diff --git a/passes/pmgen/xilinx_dsp_CREG.pmg b/passes/pmgen/xilinx_dsp_CREG.pmg
index 5cd34162e..b20e4f458 100644
--- a/passes/pmgen/xilinx_dsp_CREG.pmg
+++ b/passes/pmgen/xilinx_dsp_CREG.pmg
@@ -1,7 +1,7 @@
 // This file describes the second of three pattern matcher setups that
 //   forms the `xilinx_dsp` pass described in xilinx_dsp.cc
 // At a high level, it works as follows:
-//   (1) Starting from a DSP48E1 cell that (a) doesn't have a CREG already,
+//   (1) Starting from a DSP48* cell that (a) doesn't have a CREG already,
 //       and (b) uses the 'C' port
 //   (2) Match the driver of the 'C' input to a possible $dff cell (CREG)
 //       (attached to at most two $mux cells that implement clock-enable or
@@ -38,10 +38,10 @@ udata <SigBit> dffclock
 udata <Cell*> dff dffcemux dffrstmux
 udata <bool> dffcepol dffrstpol
 
-// (1) Starting from a DSP48E1 cell that (a) doesn't have a CREG already,
+// (1) Starting from a DSP48* cell that (a) doesn't have a CREG already,
 //     and (b) uses the 'C' port
 match dsp
-	select dsp->type.in(\DSP48E1)
+	select dsp->type.in(\DSP48A, \DSP48A1, \DSP48E1)
 	select param(dsp, \CREG, 1).as_int() == 0
 	select nusers(port(dsp, \C, SigSpec())) > 1
 endmatch
@@ -60,7 +60,8 @@ code sigC sigP clock
 	sigC = unextend(port(dsp, \C, SigSpec()));
 
 	SigSpec P = port(dsp, \P);
-	if (param(dsp, \USE_MULT, Const("MULTIPLY")).decode_string() == "MULTIPLY") {
+	if (!dsp->type.in(\DSP48E1) ||
+ param(dsp, \USE_MULT, Const("MULTIPLY")).decode_string() == "MULTIPLY") {
 		// Only care about those bits that are used
 		int i;
 		for (i = GetSize(P)-1; i >= 0; i--)
diff --git a/passes/pmgen/xilinx_dsp_cascade.pmg b/passes/pmgen/xilinx_dsp_cascade.pmg
index 7a32df2b7..b14a1ee0a 100644
--- a/passes/pmgen/xilinx_dsp_cascade.pmg
+++ b/passes/pmgen/xilinx_dsp_cascade.pmg
@@ -62,12 +62,11 @@ code
 #define MAX_DSP_CASCADE 20
 endcode
 
-// (1) Starting from a DSP48E1 cell that (a) has the Z multiplexer
-//     (controlled by OPMODE[6:4]) set to zero and (b) doesn't already
-//     use the 'PCOUT' port
+// (1) Starting from a DSP48* cell that (a) has the Z multiplexer
+//     (controlled by OPMODE[3:2] for DSP48A*, by OPMODE[6:4] for DSP48E1)
+//     set to zero and (b) doesn't already use the 'PCOUT' port
 match first
-	select first->type.in(\DSP48E1)
-	select port(first, \OPMODE, Const(0, 7)).extract(4,3) == Const::from_string("000")
+	select (first->type.in(\DSP48A, \DSP48A1) && port(first, \OPMODE, Const(0, 8)).extract(2,2) == Const::from_string("00")) || (first->type.in(\DSP48E1) && port(first, \OPMODE, Const(0, 7)).extract(4,3) == Const::from_string("000"))
 	select nusers(port(first, \PCOUT, SigSpec())) <= 1
 endmatch
 
@@ -100,14 +99,21 @@ finally
 					add_siguser(cascade, dsp);
 
 					SigSpec opmode = port(dsp_pcin, \OPMODE, Const(0, 7));
-					if (P == 17)
-						opmode[6] = State::S1;
-					else if (P == 0)
-						opmode[6] = State::S0;
-					else log_abort();
-
-					opmode[5] = State::S0;
-					opmode[4] = State::S1;
+					if (dsp->type.in(\DSP48A, \DSP48A1)) {
+						log_assert(P == 0);
+						opmode[3] = State::S0;
+						opmode[2] = State::S1;
+					}
+					else if (dsp->type.in(\DSP48E1)) {
+						if (P == 17)
+							opmode[6] = State::S1;
+						else if (P == 0)
+							opmode[6] = State::S0;
+						else log_abort();
+
+						opmode[5] = State::S0;
+						opmode[4] = State::S1;
+					}
 					dsp_pcin->setPort(\OPMODE, opmode);
 
 					log_debug("PCOUT -> PCIN cascade for %s -> %s\n", log_id(dsp), log_id(dsp_pcin));
@@ -120,21 +126,42 @@ finally
 					add_siguser(cascade, dsp_pcin);
 					add_siguser(cascade, dsp);
 
-					dsp->setParam(ID(ACASCREG), AREG);
+					if (dsp->type.in(\DSP48E1))
+						dsp->setParam(ID(ACASCREG), AREG);
 					dsp_pcin->setParam(ID(A_INPUT), Const("CASCADE"));
 
 					log_debug("ACOUT -> ACIN cascade for %s -> %s\n", log_id(dsp), log_id(dsp_pcin));
 				}
 				if (BREG >= 0) {
 					Wire *cascade = module->addWire(NEW_ID, 18);
-					dsp_pcin->setPort(ID(B), Const(0, 18));
-					dsp_pcin->setPort(ID(BCIN), cascade);
+					if (dsp->type.in(\DSP48A, \DSP48A1)) {
+						// According to UG389 p9 [https://www.xilinx.com/support/documentation/user_guides/ug389.pdf]
+						// "The DSP48A1 component uses this input when cascading
+						//   BCOUT from an adjacent DSP48A1 slice. The tools then
+						//   translate BCOUT cascading to the dedicated BCIN input
+						//   and set the B_INPUT attribute for implementation."
+						dsp_pcin->setPort(ID(B), cascade);
+					}
+					else {
+						dsp_pcin->setPort(ID(B), Const(0, 18));
+						dsp_pcin->setPort(ID(BCIN), cascade);
+					}
 					dsp->setPort(ID(BCOUT), cascade);
 					add_siguser(cascade, dsp_pcin);
 					add_siguser(cascade, dsp);
 
-					dsp->setParam(ID(BCASCREG), BREG);
-					dsp_pcin->setParam(ID(B_INPUT), Const("CASCADE"));
+					if (dsp->type.in(\DSP48E1)) {
+						dsp->setParam(ID(BCASCREG), BREG);
+						// According to UG389 p13 [https://www.xilinx.com/support/documentation/user_guides/ug389.pdf]
+						// "The attribute is only used by place and route tools and
+						//   is not necessary for the users to set for synthesis. The
+						//   attribute is determined by the connection to the B port
+						//   of the DSP48A1 slice. If the B port is connected to the
+						//   BCOUT of another DSP48A1 slice, then the tools automatically
+						//   set the attribute to 'CASCADE', otherwise it is set to
+						//   'DIRECT'".
+						dsp_pcin->setParam(ID(B_INPUT), Const("CASCADE"));
+					}
 
 					log_debug("BCOUT -> BCIN cascade for %s -> %s\n", log_id(dsp), log_id(dsp_pcin));
 				}
@@ -156,22 +183,21 @@ subpattern tail
 arg first
 arg next
 
-// (2.1) Match another DSP48E1 cell that (a) does not have the CREG enabled,
+// (2.1) Match another DSP48* cell that (a) does not have the CREG enabled,
 //       (b) has its Z multiplexer output set to the 'C' port, which is
 //       driven by the 'P' output of the previous DSP cell, and (c) has its
 //       'PCIN' port unused
 match nextP
-	select nextP->type.in(\DSP48E1)
 	select !param(nextP, \CREG, State::S1).as_bool()
-	select port(nextP, \OPMODE, Const(0, 7)).extract(4,3) == Const::from_string("011")
+	select (nextP->type.in(\DSP48A, \DSP48A1) && port(nextP, \OPMODE, Const(0, 8)).extract(2,2) == Const::from_string("11")) || (nextP->type.in(\DSP48E1) && port(nextP, \OPMODE, Const(0, 7)).extract(4,3) == Const::from_string("011"))
 	select nusers(port(nextP, \C, SigSpec())) > 1
 	select nusers(port(nextP, \PCIN, SigSpec())) == 0
 	index <SigBit> port(nextP, \C)[0] === port(std::get<0>(chain.back()), \P)[0]
 	semioptional
 endmatch
 
-// (2.2) Same as (2.1) but with the 'C' port driven by the 'P' output of the
-//       previous DSP cell right-shifted by 17 bits
+// (2.2) For DSP48E1 only, same as (2.1) but with the 'C' port driven
+//       by the 'P' output of the previous DSP cell right-shifted by 17 bits
 match nextP_shift17
 	if !nextP
 	select nextP_shift17->type.in(\DSP48E1)
@@ -188,6 +214,8 @@ code next
 	if (!nextP)
 		next = nextP_shift17;
 	if (next) {
+		if (next->type != first->type)
+			reject;
 		unextend = [](const SigSpec &sig) {
 			int i;
 			for (i = GetSize(sig)-1; i > 0; i--)
@@ -202,38 +230,50 @@ code next
 endcode
 
 // (3) For this subequent DSP48E1 match (i.e. PCOUT -> PCIN cascade exists)
-//     if (a) the previous DSP48E1 uses either the A2REG or A1REG, (b) this
-//     DSP48 does not use A2REG nor A1REG, (c) this DSP48E1 does not already
-//     have an ACOUT -> ACIN cascade, (d) the previous DSP does not already
-//     use its ACOUT port, then examine if an ACOUT -> ACIN cascade
-//     opportunity exists by matching for a $dff-with-optional-clock-enable-
-//     or-reset and checking that the 'D' input of this register is the same
-//     as the 'A' input of the previous DSP
+//     if (a) this DSP48E1 does not already have an ACOUT -> ACIN cascade,
+//     (b) the previous DSP does  not already use its ACOUT port, then
+//     examine if an ACOUT -> ACIN cascade  opportunity exists if
+//     (i) A ports are identical, or (ii) separated by a
+//     $dff-with-optional-clock-enable-or-reset and checking that the 'D' input
+//     of this register is the same as the 'A' input of the previous DSP
+//     TODO: Check for two levels of flops, instead of just one
 code argQ clock AREG
 	AREG = -1;
-	if (next) {
+	if (next && next->type.in(\DSP48E1)) {
 		Cell *prev = std::get<0>(chain.back());
-		if (param(prev, \AREG, 2).as_int() > 0 &&
-				param(next, \AREG, 2).as_int() > 0 &&
-				param(next, \A_INPUT, Const("DIRECT")).decode_string() == "DIRECT" &&
+
+		if (param(next, \A_INPUT, Const("DIRECT")).decode_string() == "DIRECT" &&
+				port(next, \ACIN, SigSpec()).is_fully_zero() &&
 				nusers(port(prev, \ACOUT, SigSpec())) <= 1) {
-			argQ = unextend(port(next, \A));
-			clock = port(prev, \CLK);
-			subpattern(in_dffe);
-			if (dff) {
-				if (!dffrstmux && port(prev, \RSTA, State::S0) != State::S0)
-					goto reject_AREG;
-				if (dffrstmux && port(dffrstmux, \S) != port(prev, \RSTA, State::S0))
-					goto reject_AREG;
-				if (!dffcemux && port(prev, \CEA2, State::S0) != State::S0)
-					goto reject_AREG;
-				if (dffcemux && port(dffcemux, \S) != port(prev, \CEA2, State::S0))
-					goto reject_AREG;
-				if (dffD == unextend(port(prev, \A)))
-					AREG = 1;
-reject_AREG:			;
+			if (param(prev, \AREG, 2) == 0) {
+				if (port(prev, \A) == port(next, \A))
+					AREG = 0;
+			}
+			else {
+				argQ = unextend(port(next, \A));
+				clock = port(prev, \CLK);
+				subpattern(in_dffe);
+				if (dff) {
+					if (!dffrstmux && port(prev, \RSTA, State::S0) != State::S0)
+						goto reject_AREG;
+					if (dffrstmux && port(dffrstmux, \S) != port(prev, \RSTA, State::S0))
+						goto reject_AREG;
+					IdString CEA;
+					if (param(prev, \AREG, 2) == 1)
+						CEA = \CEA2;
+					else if (param(prev, \AREG, 2) == 2)
+						CEA = \CEA1;
+					else log_abort();
+					if (!dffcemux && port(prev, CEA, State::S0) != State::S1)
+						goto reject_AREG;
+					if (dffcemux && port(dffcemux, \S) != port(prev, CEA, State::S0))
+						goto reject_AREG;
+					if (dffD == unextend(port(prev, \A)))
+						AREG = 1;
+				}
 			}
 		}
+reject_AREG:	;
 	}
 endcode
 
@@ -242,28 +282,47 @@ code argQ clock BREG
 	BREG = -1;
 	if (next) {
 		Cell *prev = std::get<0>(chain.back());
-		if (param(prev, \BREG, 2).as_int() > 0 &&
-				param(next, \BREG, 2).as_int() > 0 &&
-				param(next, \B_INPUT, Const("DIRECT")).decode_string() == "DIRECT" &&
+		if (param(next, \B_INPUT, Const("DIRECT")).decode_string() == "DIRECT" &&
 				port(next, \BCIN, SigSpec()).is_fully_zero() &&
 				nusers(port(prev, \BCOUT, SigSpec())) <= 1) {
-			argQ = unextend(port(next, \B));
-			clock = port(prev, \CLK);
-			subpattern(in_dffe);
-			if (dff) {
-				if (!dffrstmux && port(prev, \RSTB, State::S0) != State::S0)
-					goto reject_BREG;
-				if (dffrstmux && port(dffrstmux, \S) != port(prev, \RSTB, State::S0))
-					goto reject_BREG;
-				if (!dffcemux && port(prev, \CEB2, State::S0) != State::S0)
-					goto reject_BREG;
-				if (dffcemux && port(dffcemux, \S) != port(prev, \CEB2, State::S0))
-					goto reject_BREG;
-				if (dffD == unextend(port(prev, \B)))
-					BREG = 1;
-reject_BREG:			;
+			if ((next->type.in(\DSP48A, \DSP48A1) && param(prev, \B0REG, 0) == 0 && param(prev, \B1REG, 1) == 0) ||
+				(next->type.in(\DSP48E1) && param(prev, \BREG, 2) == 0)) {
+				if (port(prev, \B) == port(next, \B))
+					BREG = 0;
+			}
+			else {
+				argQ = unextend(port(next, \B));
+				clock = port(prev, \CLK);
+				subpattern(in_dffe);
+				if (dff) {
+					if (!dffrstmux && port(prev, \RSTB, State::S0) != State::S0)
+						goto reject_BREG;
+					if (dffrstmux && port(dffrstmux, \S) != port(prev, \RSTB, State::S0))
+						goto reject_BREG;
+					IdString CEB;
+					if (next->type.in(\DSP48A, \DSP48A1))
+						CEB = \CEB;
+					else if (next->type.in(\DSP48E1)) {
+						if (param(prev, \BREG, 2) == 1)
+							CEB = \CEB2;
+						else if (param(prev, \BREG, 2) == 2)
+							CEB = \CEB1;
+						else log_abort();
+					}
+					else log_abort();
+					if (!dffcemux && port(prev, CEB, State::S0) != State::S1)
+						goto reject_BREG;
+					if (dffcemux && port(dffcemux, \S) != port(prev, CEB, State::S0))
+						goto reject_BREG;
+					if (dffD == unextend(port(prev, \B))) {
+						if (next->type.in(\DSP48A, \DSP48A1) && param(prev, \B0REG, 0) != 0)
+							goto reject_BREG;
+						BREG = 1;
+					}
+				}
 			}
 		}
+reject_BREG:	;
 	}
 endcode
 
diff --git a/passes/proc/proc_dlatch.cc b/passes/proc/proc_dlatch.cc
index d9d5dfbed..a0c8351b6 100644
--- a/passes/proc/proc_dlatch.cc
+++ b/passes/proc/proc_dlatch.cc
@@ -349,6 +349,10 @@ void proc_dlatch(proc_dlatch_db_t &db, RTLIL::Process *proc)
 			continue;
 		}
 
+		if (proc->get_bool_attribute(ID(always_ff)))
+			log_error("Found non edge/level sensitive event in always_ff process `%s.%s'.\n",
+					db.module->name.c_str(), proc->name.c_str());
+
 		for (auto ss : sr->actions)
 		{
 			db.sigmap.apply(ss.first);
@@ -383,8 +387,12 @@ void proc_dlatch(proc_dlatch_db_t &db, RTLIL::Process *proc)
 	int offset = 0;
 	for (auto chunk : nolatches_bits.first.chunks()) {
 		SigSpec lhs = chunk, rhs = nolatches_bits.second.extract(offset, chunk.width);
-		log("No latch inferred for signal `%s.%s' from process `%s.%s'.\n",
-				db.module->name.c_str(), log_signal(lhs), db.module->name.c_str(), proc->name.c_str());
+		if (proc->get_bool_attribute(ID(always_latch)))
+			log_error("No latch inferred for signal `%s.%s' from always_latch process `%s.%s'.\n",
+					db.module->name.c_str(), log_signal(lhs), db.module->name.c_str(), proc->name.c_str());
+		else
+			log("No latch inferred for signal `%s.%s' from process `%s.%s'.\n",
+					db.module->name.c_str(), log_signal(lhs), db.module->name.c_str(), proc->name.c_str());
 		db.module->connect(lhs, rhs);
 		offset += chunk.width;
 	}
@@ -410,8 +418,12 @@ void proc_dlatch(proc_dlatch_db_t &db, RTLIL::Process *proc)
 			cell->set_src_attribute(src);
 			db.generated_dlatches.insert(cell);
 
-			log("Latch inferred for signal `%s.%s' from process `%s.%s': %s\n",
-					db.module->name.c_str(), log_signal(lhs), db.module->name.c_str(), proc->name.c_str(), log_id(cell));
+			if (proc->get_bool_attribute(ID(always_comb)))
+				log_error("Latch inferred for signal `%s.%s' from always_comb process `%s.%s'.\n",
+						db.module->name.c_str(), log_signal(lhs), db.module->name.c_str(), proc->name.c_str());
+			else
+				log("Latch inferred for signal `%s.%s' from process `%s.%s': %s\n",
+						db.module->name.c_str(), log_signal(lhs), db.module->name.c_str(), proc->name.c_str(), log_id(cell));
 		}
 
 		offset += width;
diff --git a/passes/sat/Makefile.inc b/passes/sat/Makefile.inc
index fc3ac879e..4bb4b0edc 100644
--- a/passes/sat/Makefile.inc
+++ b/passes/sat/Makefile.inc
@@ -12,4 +12,5 @@ OBJS += passes/sat/supercover.o
 OBJS += passes/sat/fmcombine.o
 OBJS += passes/sat/mutate.o
 OBJS += passes/sat/cutpoint.o
+OBJS += passes/sat/fminit.o
 
diff --git a/passes/sat/fminit.cc b/passes/sat/fminit.cc
new file mode 100644
index 000000000..f3f00b382
--- /dev/null
+++ b/passes/sat/fminit.cc
@@ -0,0 +1,197 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "kernel/yosys.h"
+#include "kernel/sigtools.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct FminitPass : public Pass {
+	FminitPass() : Pass("fminit", "set init values/sequences for formal") { }
+	void help() YS_OVERRIDE
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    fminit [options] <selection>\n");
+		log("\n");
+		log("This pass creates init constraints (for example for reset sequences) in a formal\n");
+		log("model.\n");
+		log("\n");
+		log("    -seq <signal> <sequence>\n");
+		log("        Set sequence using comma-separated list of values, use 'z for\n");
+		log("        unconstrained bits. The last value is used for the remainder of the\n");
+		log("        trace.\n");
+		log("\n");
+		log("    -set <signal> <value>\n");
+		log("        Add constant value constraint\n");
+		log("\n");
+		log("    -posedge <signal>\n");
+		log("    -negedge <signal>\n");
+		log("        Set clock for init sequences\n");
+		log("\n");
+	}
+	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
+	{
+		vector<pair<string, vector<string>>> initdata;
+		vector<pair<string, string>> setdata;
+		string clocksignal;
+		bool clockedge;
+
+		log_header(design, "Executing FMINIT pass.\n");
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++)
+		{
+			// if (args[argidx] == "-o" && argidx+1 < args.size()) {
+			// 	filename = args[++argidx];
+			// 	continue;
+			// }
+			if (args[argidx] == "-seq" && argidx+2 < args.size()) {
+				string lhs = args[++argidx];
+				string rhs = args[++argidx];
+				initdata.push_back(make_pair(lhs, split_tokens(rhs, ",")));
+				continue;
+			}
+			if (args[argidx] == "-set" && argidx+2 < args.size()) {
+				string lhs = args[++argidx];
+				string rhs = args[++argidx];
+				setdata.push_back(make_pair(lhs, rhs));
+				continue;
+			}
+			if (args[argidx] == "-posedge" && argidx+1 < args.size()) {
+				clocksignal = args[++argidx];
+				clockedge = true;
+				continue;
+			}
+			if (args[argidx] == "-negedge" && argidx+1 < args.size()) {
+				clocksignal = args[++argidx];
+				clockedge = true;
+				continue;
+			}
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		Module *module = nullptr;
+
+		for (auto mod : design->selected_modules()) {
+			if (module != nullptr)
+				log_error("'fminit' requires exactly one module to be selected.\n");
+			module = mod;
+		}
+
+		if (module == nullptr)
+			log_error("'fminit' requires exactly one module to be selected.\n");
+
+		SigSpec clksig;
+		if (!clocksignal.empty()) {
+			if (!SigSpec::parse(clksig, module, clocksignal))
+				log_error("Error parsing expression '%s'.\n", clocksignal.c_str());
+		}
+
+		for (auto &it : setdata)
+		{
+			SigSpec lhs, rhs;
+
+			if (!SigSpec::parse(lhs, module, it.first))
+				log_error("Error parsing expression '%s'.\n", it.first.c_str());
+
+			if (!SigSpec::parse_rhs(lhs, rhs, module, it.second))
+				log_error("Error parsing expression '%s'.\n", it.second.c_str());
+
+			SigSpec final_lhs, final_rhs;
+
+			for (int i = 0; i < GetSize(rhs); i++)
+				if (rhs[i] != State::Sz) {
+					final_lhs.append(lhs[i]);
+					final_rhs.append(rhs[i]);
+				}
+
+			if (!final_lhs.empty()) {
+				SigSpec eq = module->Eq(NEW_ID, final_lhs, final_rhs);
+				module->addAssume(NEW_ID, eq, State::S1);
+			}
+		}
+
+		vector<SigSpec> ctrlsig;
+		vector<SigSpec> ctrlsig_latched;
+
+		for (auto &it : initdata)
+		{
+			SigSpec lhs, rhs;
+
+			if (!SigSpec::parse(lhs, module, it.first))
+				log_error("Error parsing expression '%s'.\n", it.first.c_str());
+
+			for (int i = 0; i < GetSize(it.second); i++)
+			{
+				if (i >= GetSize(ctrlsig))
+				{
+					SigSpec insig = i > 0 ? ctrlsig.at(i-1) : State::S0;
+
+					Wire *outwire = module->addWire(NEW_ID);
+					outwire->attributes[ID(init)] = i > 0 ? State::S0 : State::S1;
+
+					if (clksig.empty())
+						module->addFf(NEW_ID, insig, outwire);
+					else
+						module->addDff(NEW_ID, clksig, insig, outwire, clockedge);
+
+					ctrlsig.push_back(outwire);
+					ctrlsig_latched.push_back(SigSpec());
+				}
+
+				if (i+1 == GetSize(it.second) && ctrlsig_latched[i].empty())
+				{
+					Wire *ffwire = module->addWire(NEW_ID);
+					ffwire->attributes[ID(init)] = State::S0;
+					SigSpec outsig = module->Or(NEW_ID, ffwire, ctrlsig[i]);
+
+					if (clksig.empty())
+						module->addFf(NEW_ID, outsig, ffwire);
+					else
+						module->addDff(NEW_ID, clksig, outsig, ffwire, clockedge);
+
+					ctrlsig_latched[i] = outsig;
+				}
+
+				SigSpec ctrl = i+1 == GetSize(it.second) ? ctrlsig_latched[i] : ctrlsig[i];
+
+				SigSpec final_lhs, final_rhs;
+
+				if (!SigSpec::parse_rhs(lhs, rhs, module, it.second[i]))
+					log_error("Error parsing expression '%s'.\n", it.second[i].c_str());
+
+				for (int i = 0; i < GetSize(rhs); i++)
+					if (rhs[i] != State::Sz) {
+						final_lhs.append(lhs[i]);
+						final_rhs.append(rhs[i]);
+					}
+
+				if (!final_lhs.empty()) {
+					SigSpec eq = module->Eq(NEW_ID, final_lhs, final_rhs);
+					module->addAssume(NEW_ID, eq, ctrl);
+				}
+			}
+		}
+	}
+} FminitPass;
+
+PRIVATE_NAMESPACE_END
diff --git a/passes/sat/sim.cc b/passes/sat/sim.cc
index 4c3022c70..d5634b26d 100644
--- a/passes/sat/sim.cc
+++ b/passes/sat/sim.cc
@@ -230,7 +230,7 @@ struct SimInstance
 		bool did_something = false;
 
 		sig = sigmap(sig);
-		log_assert(GetSize(sig) == GetSize(value));
+		log_assert(GetSize(sig) <= GetSize(value));
 
 		for (int i = 0; i < GetSize(sig); i++)
 			if (state_nets.at(sig[i]) != value[i]) {
diff --git a/passes/techmap/abc.cc b/passes/techmap/abc.cc
index b29480e26..581652a41 100644
--- a/passes/techmap/abc.cc
+++ b/passes/techmap/abc.cc
@@ -29,17 +29,17 @@
 // Kahn, Arthur B. (1962), "Topological sorting of large networks", Communications of the ACM 5 (11): 558-562, doi:10.1145/368996.369025
 // http://en.wikipedia.org/wiki/Topological_sorting
 
-#define ABC_COMMAND_LIB "strash; ifraig; scorr; dc2; dretime; retime {D}; strash; &get -n; &dch -f; &nf {D}; &put"
-#define ABC_COMMAND_CTR "strash; ifraig; scorr; dc2; dretime; retime {D}; strash; &get -n; &dch -f; &nf {D}; &put; buffer; upsize {D}; dnsize {D}; stime -p"
-#define ABC_COMMAND_LUT "strash; ifraig; scorr; dc2; dretime; retime {D}; strash; dch -f; if; mfs2"
-#define ABC_COMMAND_SOP "strash; ifraig; scorr; dc2; dretime; retime {D}; strash; dch -f; cover {I} {P}"
-#define ABC_COMMAND_DFL "strash; ifraig; scorr; dc2; dretime; retime {D}; strash; &get -n; &dch -f; &nf {D}; &put"
-
-#define ABC_FAST_COMMAND_LIB "strash; dretime; retime {D}; map {D}"
-#define ABC_FAST_COMMAND_CTR "strash; dretime; retime {D}; map {D}; buffer; upsize {D}; dnsize {D}; stime -p"
-#define ABC_FAST_COMMAND_LUT "strash; dretime; retime {D}; if"
-#define ABC_FAST_COMMAND_SOP "strash; dretime; retime {D}; cover -I {I} -P {P}"
-#define ABC_FAST_COMMAND_DFL "strash; dretime; retime {D}; map"
+#define ABC_COMMAND_LIB "strash; ifraig; scorr; dc2; dretime; strash; &get -n; &dch -f; &nf {D}; &put"
+#define ABC_COMMAND_CTR "strash; ifraig; scorr; dc2; dretime; strash; &get -n; &dch -f; &nf {D}; &put; buffer; upsize {D}; dnsize {D}; stime -p"
+#define ABC_COMMAND_LUT "strash; ifraig; scorr; dc2; dretime; strash; dch -f; if; mfs2"
+#define ABC_COMMAND_SOP "strash; ifraig; scorr; dc2; dretime; strash; dch -f; cover {I} {P}"
+#define ABC_COMMAND_DFL "strash; ifraig; scorr; dc2; dretime; strash; &get -n; &dch -f; &nf {D}; &put"
+
+#define ABC_FAST_COMMAND_LIB "strash; dretime; map {D}"
+#define ABC_FAST_COMMAND_CTR "strash; dretime; map {D}; buffer; upsize {D}; dnsize {D}; stime -p"
+#define ABC_FAST_COMMAND_LUT "strash; dretime; if"
+#define ABC_FAST_COMMAND_SOP "strash; dretime; cover -I {I} -P {P}"
+#define ABC_FAST_COMMAND_DFL "strash; dretime; map"
 
 #include "kernel/register.h"
 #include "kernel/sigtools.h"
@@ -747,6 +747,10 @@ void abc_module(RTLIL::Design *design, RTLIL::Module *current_module, std::strin
 	else
 		abc_script += fast_mode ? ABC_FAST_COMMAND_DFL : ABC_COMMAND_DFL;
 
+	if (script_file.empty() && !delay_target.empty())
+		for (size_t pos = abc_script.find("dretime;"); pos != std::string::npos; pos = abc_script.find("dretime;", pos+1))
+			abc_script = abc_script.substr(0, pos) + "dretime; retime -o {D};" + abc_script.substr(pos+8);
+
 	for (size_t pos = abc_script.find("{D}"); pos != std::string::npos; pos = abc_script.find("{D}", pos))
 		abc_script = abc_script.substr(0, pos) + delay_target + abc_script.substr(pos+3);
 
@@ -1510,7 +1514,47 @@ struct AbcPass : public Pass {
 #endif
 #endif
 
-		size_t argidx;
+		// get arguments from scratchpad first, then override by command arguments
+		std::string lut_arg, luts_arg, g_arg;
+		exe_file = design->scratchpad_get_string("abc.exe", exe_file /* inherit default value if not set */);
+		script_file = design->scratchpad_get_string("abc.script", script_file);
+		liberty_file = design->scratchpad_get_string("abc.liberty", liberty_file);
+		constr_file = design->scratchpad_get_string("abc.constr", constr_file);
+		if (design->scratchpad.count("abc.D")) {
+			delay_target = "-D " + design->scratchpad_get_string("abc.D");
+		}
+		if (design->scratchpad.count("abc.I")) {
+			sop_inputs = "-I " + design->scratchpad_get_string("abc.I");
+		}
+		if (design->scratchpad.count("abc.P")) {
+			sop_products = "-P " + design->scratchpad_get_string("abc.P");
+		}
+		if (design->scratchpad.count("abc.S")) {
+			lutin_shared = "-S " + design->scratchpad_get_string("abc.S");
+		}
+		lut_arg = design->scratchpad_get_string("abc.lut", lut_arg);
+		luts_arg = design->scratchpad_get_string("abc.luts", luts_arg);
+		sop_mode = design->scratchpad_get_bool("abc.sop", sop_mode);
+		map_mux4 = design->scratchpad_get_bool("abc.mux4", map_mux4);
+		map_mux8 = design->scratchpad_get_bool("abc.mux8", map_mux8);
+		map_mux16 = design->scratchpad_get_bool("abc.mux16", map_mux16);
+		abc_dress = design->scratchpad_get_bool("abc.dress", abc_dress);
+		g_arg = design->scratchpad_get_string("abc.g", g_arg);
+
+		fast_mode = design->scratchpad_get_bool("abc.fast", fast_mode);
+		dff_mode = design->scratchpad_get_bool("abc.dff", dff_mode);
+		if (design->scratchpad.count("abc.clk")) {
+			clk_str = design->scratchpad_get_string("abc.clk");
+			dff_mode = true;
+		}
+		keepff = design->scratchpad_get_bool("abc.keepff", keepff);
+		cleanup = !design->scratchpad_get_bool("abc.nocleanup", !cleanup);
+		keepff = design->scratchpad_get_bool("abc.keepff", keepff);
+		show_tempdir = design->scratchpad_get_bool("abc.showtmp", show_tempdir);
+		markgroups = design->scratchpad_get_bool("abc.markgroups", markgroups);
+
+		size_t argidx, g_argidx;
+		bool g_arg_from_cmd = false;
 		char pwd [PATH_MAX];
 		if (!getcwd(pwd, sizeof(pwd))) {
 			log_cmd_error("getcwd failed: %s\n", strerror(errno));
@@ -1524,23 +1568,14 @@ struct AbcPass : public Pass {
 			}
 			if (arg == "-script" && argidx+1 < args.size()) {
 				script_file = args[++argidx];
-				rewrite_filename(script_file);
-				if (!script_file.empty() && !is_absolute_path(script_file) && script_file[0] != '+')
-					script_file = std::string(pwd) + "/" + script_file;
 				continue;
 			}
 			if (arg == "-liberty" && argidx+1 < args.size()) {
 				liberty_file = args[++argidx];
-				rewrite_filename(liberty_file);
-				if (!liberty_file.empty() && !is_absolute_path(liberty_file))
-					liberty_file = std::string(pwd) + "/" + liberty_file;
 				continue;
 			}
 			if (arg == "-constr" && argidx+1 < args.size()) {
-				rewrite_filename(constr_file);
 				constr_file = args[++argidx];
-				if (!constr_file.empty() && !is_absolute_path(constr_file))
-					constr_file = std::string(pwd) + "/" + constr_file;
 				continue;
 			}
 			if (arg == "-D" && argidx+1 < args.size()) {
@@ -1560,37 +1595,11 @@ struct AbcPass : public Pass {
 				continue;
 			}
 			if (arg == "-lut" && argidx+1 < args.size()) {
-				string arg = args[++argidx];
-				size_t pos = arg.find_first_of(':');
-				int lut_mode = 0, lut_mode2 = 0;
-				if (pos != string::npos) {
-					lut_mode = atoi(arg.substr(0, pos).c_str());
-					lut_mode2 = atoi(arg.substr(pos+1).c_str());
-				} else {
-					lut_mode = atoi(arg.c_str());
-					lut_mode2 = lut_mode;
-				}
-				lut_costs.clear();
-				for (int i = 0; i < lut_mode; i++)
-					lut_costs.push_back(1);
-				for (int i = lut_mode; i < lut_mode2; i++)
-					lut_costs.push_back(2 << (i - lut_mode));
+				lut_arg = args[++argidx];
 				continue;
 			}
 			if (arg == "-luts" && argidx+1 < args.size()) {
-				lut_costs.clear();
-				for (auto &tok : split_tokens(args[++argidx], ",")) {
-					auto parts = split_tokens(tok, ":");
-					if (GetSize(parts) == 0 && !lut_costs.empty())
-						lut_costs.push_back(lut_costs.back());
-					else if (GetSize(parts) == 1)
-						lut_costs.push_back(atoi(parts.at(0).c_str()));
-					else if (GetSize(parts) == 2)
-						while (GetSize(lut_costs) < std::atoi(parts.at(0).c_str()))
-							lut_costs.push_back(atoi(parts.at(1).c_str()));
-					else
-						log_cmd_error("Invalid -luts syntax.\n");
-				}
+				luts_arg = args[++argidx];
 				continue;
 			}
 			if (arg == "-sop") {
@@ -1614,123 +1623,11 @@ struct AbcPass : public Pass {
 				continue;
 			}
 			if (arg == "-g" && argidx+1 < args.size()) {
-				for (auto g : split_tokens(args[++argidx], ",")) {
-					vector<string> gate_list;
-					bool remove_gates = false;
-					if (GetSize(g) > 0 && g[0] == '-') {
-						remove_gates = true;
-						g = g.substr(1);
-					}
-					if (g == "AND") goto ok_gate;
-					if (g == "NAND") goto ok_gate;
-					if (g == "OR") goto ok_gate;
-					if (g == "NOR") goto ok_gate;
-					if (g == "XOR") goto ok_gate;
-					if (g == "XNOR") goto ok_gate;
-					if (g == "ANDNOT") goto ok_gate;
-					if (g == "ORNOT") goto ok_gate;
-					if (g == "MUX") goto ok_gate;
-					if (g == "NMUX") goto ok_gate;
-					if (g == "AOI3") goto ok_gate;
-					if (g == "OAI3") goto ok_gate;
-					if (g == "AOI4") goto ok_gate;
-					if (g == "OAI4") goto ok_gate;
-					if (g == "simple") {
-						gate_list.push_back("AND");
-						gate_list.push_back("OR");
-						gate_list.push_back("XOR");
-						gate_list.push_back("MUX");
-						goto ok_alias;
-					}
-					if (g == "cmos2") {
-						if (!remove_gates)
-							cmos_cost = true;
-						gate_list.push_back("NAND");
-						gate_list.push_back("NOR");
-						goto ok_alias;
-					}
-					if (g == "cmos3") {
-						if (!remove_gates)
-							cmos_cost = true;
-						gate_list.push_back("NAND");
-						gate_list.push_back("NOR");
-						gate_list.push_back("AOI3");
-						gate_list.push_back("OAI3");
-						goto ok_alias;
-					}
-					if (g == "cmos4") {
-						if (!remove_gates)
-							cmos_cost = true;
-						gate_list.push_back("NAND");
-						gate_list.push_back("NOR");
-						gate_list.push_back("AOI3");
-						gate_list.push_back("OAI3");
-						gate_list.push_back("AOI4");
-						gate_list.push_back("OAI4");
-						goto ok_alias;
-					}
-					if (g == "cmos") {
-						if (!remove_gates)
-							cmos_cost = true;
-						gate_list.push_back("NAND");
-						gate_list.push_back("NOR");
-						gate_list.push_back("AOI3");
-						gate_list.push_back("OAI3");
-						gate_list.push_back("AOI4");
-						gate_list.push_back("OAI4");
-						gate_list.push_back("NMUX");
-						gate_list.push_back("MUX");
-						gate_list.push_back("XOR");
-						gate_list.push_back("XNOR");
-						goto ok_alias;
-					}
-					if (g == "gates") {
-						gate_list.push_back("AND");
-						gate_list.push_back("NAND");
-						gate_list.push_back("OR");
-						gate_list.push_back("NOR");
-						gate_list.push_back("XOR");
-						gate_list.push_back("XNOR");
-						gate_list.push_back("ANDNOT");
-						gate_list.push_back("ORNOT");
-						goto ok_alias;
-					}
-					if (g == "aig") {
-						gate_list.push_back("AND");
-						gate_list.push_back("NAND");
-						gate_list.push_back("OR");
-						gate_list.push_back("NOR");
-						gate_list.push_back("ANDNOT");
-						gate_list.push_back("ORNOT");
-						goto ok_alias;
-					}
-					if (g == "all") {
-						gate_list.push_back("AND");
-						gate_list.push_back("NAND");
-						gate_list.push_back("OR");
-						gate_list.push_back("NOR");
-						gate_list.push_back("XOR");
-						gate_list.push_back("XNOR");
-						gate_list.push_back("ANDNOT");
-						gate_list.push_back("ORNOT");
-						gate_list.push_back("AOI3");
-						gate_list.push_back("OAI3");
-						gate_list.push_back("AOI4");
-						gate_list.push_back("OAI4");
-						gate_list.push_back("MUX");
-						gate_list.push_back("NMUX");
-					}
-					cmd_error(args, argidx, stringf("Unsupported gate type: %s", g.c_str()));
-				ok_gate:
-					gate_list.push_back(g);
-				ok_alias:
-					for (auto gate : gate_list) {
-						if (remove_gates)
-							enabled_gates.erase(gate);
-						else
-							enabled_gates.insert(gate);
-					}
-				}
+				if (g_arg_from_cmd)
+					log_cmd_error("Can only use -g once. Please combine.");
+				g_arg = args[++argidx];
+				g_argidx = argidx;
+				g_arg_from_cmd = true;
 				continue;
 			}
 			if (arg == "-fast") {
@@ -1766,8 +1663,176 @@ struct AbcPass : public Pass {
 		}
 		extra_args(args, argidx, design);
 
+		rewrite_filename(script_file);
+		if (!script_file.empty() && !is_absolute_path(script_file) && script_file[0] != '+')
+			script_file = std::string(pwd) + "/" + script_file;
+		rewrite_filename(liberty_file);
+		if (!liberty_file.empty() && !is_absolute_path(liberty_file))
+			liberty_file = std::string(pwd) + "/" + liberty_file;
+		rewrite_filename(constr_file);
+		if (!constr_file.empty() && !is_absolute_path(constr_file))
+			constr_file = std::string(pwd) + "/" + constr_file;
+
+		// handle -lut argument
+		if (!lut_arg.empty()) {
+			size_t pos = lut_arg.find_first_of(':');
+			int lut_mode = 0, lut_mode2 = 0;
+			if (pos != string::npos) {
+				lut_mode = atoi(lut_arg.substr(0, pos).c_str());
+				lut_mode2 = atoi(lut_arg.substr(pos+1).c_str());
+			} else {
+				lut_mode = atoi(lut_arg.c_str());
+				lut_mode2 = lut_mode;
+			}
+			lut_costs.clear();
+			for (int i = 0; i < lut_mode; i++)
+				lut_costs.push_back(1);
+			for (int i = lut_mode; i < lut_mode2; i++)
+				lut_costs.push_back(2 << (i - lut_mode));
+		}
+		//handle -luts argument
+		if (!luts_arg.empty()){
+			lut_costs.clear();
+			for (auto &tok : split_tokens(luts_arg, ",")) {
+				auto parts = split_tokens(tok, ":");
+				if (GetSize(parts) == 0 && !lut_costs.empty())
+					lut_costs.push_back(lut_costs.back());
+				else if (GetSize(parts) == 1)
+					lut_costs.push_back(atoi(parts.at(0).c_str()));
+				else if (GetSize(parts) == 2)
+					while (GetSize(lut_costs) < std::atoi(parts.at(0).c_str()))
+						lut_costs.push_back(atoi(parts.at(1).c_str()));
+				else
+					log_cmd_error("Invalid -luts syntax.\n");
+			}
+		}
+
+		// handle -g argument
+		if (!g_arg.empty()){
+			for (auto g : split_tokens(g_arg, ",")) {
+				vector<string> gate_list;
+				bool remove_gates = false;
+				if (GetSize(g) > 0 && g[0] == '-') {
+					remove_gates = true;
+					g = g.substr(1);
+				}
+				if (g == "AND") goto ok_gate;
+				if (g == "NAND") goto ok_gate;
+				if (g == "OR") goto ok_gate;
+				if (g == "NOR") goto ok_gate;
+				if (g == "XOR") goto ok_gate;
+				if (g == "XNOR") goto ok_gate;
+				if (g == "ANDNOT") goto ok_gate;
+				if (g == "ORNOT") goto ok_gate;
+				if (g == "MUX") goto ok_gate;
+				if (g == "NMUX") goto ok_gate;
+				if (g == "AOI3") goto ok_gate;
+				if (g == "OAI3") goto ok_gate;
+				if (g == "AOI4") goto ok_gate;
+				if (g == "OAI4") goto ok_gate;
+				if (g == "simple") {
+					gate_list.push_back("AND");
+					gate_list.push_back("OR");
+					gate_list.push_back("XOR");
+					gate_list.push_back("MUX");
+					goto ok_alias;
+				}
+				if (g == "cmos2") {
+					if (!remove_gates)
+						cmos_cost = true;
+					gate_list.push_back("NAND");
+					gate_list.push_back("NOR");
+					goto ok_alias;
+				}
+				if (g == "cmos3") {
+					if (!remove_gates)
+						cmos_cost = true;
+					gate_list.push_back("NAND");
+					gate_list.push_back("NOR");
+					gate_list.push_back("AOI3");
+					gate_list.push_back("OAI3");
+					goto ok_alias;
+				}
+				if (g == "cmos4") {
+					if (!remove_gates)
+						cmos_cost = true;
+					gate_list.push_back("NAND");
+					gate_list.push_back("NOR");
+					gate_list.push_back("AOI3");
+					gate_list.push_back("OAI3");
+					gate_list.push_back("AOI4");
+					gate_list.push_back("OAI4");
+					goto ok_alias;
+				}
+				if (g == "cmos") {
+					if (!remove_gates)
+						cmos_cost = true;
+					gate_list.push_back("NAND");
+					gate_list.push_back("NOR");
+					gate_list.push_back("AOI3");
+					gate_list.push_back("OAI3");
+					gate_list.push_back("AOI4");
+					gate_list.push_back("OAI4");
+					gate_list.push_back("NMUX");
+					gate_list.push_back("MUX");
+					gate_list.push_back("XOR");
+					gate_list.push_back("XNOR");
+					goto ok_alias;
+				}
+				if (g == "gates") {
+					gate_list.push_back("AND");
+					gate_list.push_back("NAND");
+					gate_list.push_back("OR");
+					gate_list.push_back("NOR");
+					gate_list.push_back("XOR");
+					gate_list.push_back("XNOR");
+					gate_list.push_back("ANDNOT");
+					gate_list.push_back("ORNOT");
+					goto ok_alias;
+				}
+				if (g == "aig") {
+					gate_list.push_back("AND");
+					gate_list.push_back("NAND");
+					gate_list.push_back("OR");
+					gate_list.push_back("NOR");
+					gate_list.push_back("ANDNOT");
+					gate_list.push_back("ORNOT");
+					goto ok_alias;
+				}
+				if (g == "all") {
+					gate_list.push_back("AND");
+					gate_list.push_back("NAND");
+					gate_list.push_back("OR");
+					gate_list.push_back("NOR");
+					gate_list.push_back("XOR");
+					gate_list.push_back("XNOR");
+					gate_list.push_back("ANDNOT");
+					gate_list.push_back("ORNOT");
+					gate_list.push_back("AOI3");
+					gate_list.push_back("OAI3");
+					gate_list.push_back("AOI4");
+					gate_list.push_back("OAI4");
+					gate_list.push_back("MUX");
+					gate_list.push_back("NMUX");
+				}
+				if (g_arg_from_cmd)
+					cmd_error(args, g_argidx, stringf("Unsupported gate type: %s", g.c_str()));
+				else
+					log_cmd_error("Unsupported gate type: %s", g.c_str());
+			ok_gate:
+				gate_list.push_back(g);
+			ok_alias:
+				for (auto gate : gate_list) {
+					if (remove_gates)
+						enabled_gates.erase(gate);
+					else
+						enabled_gates.insert(gate);
+				}
+			}
+		}
+
 		if (!lut_costs.empty() && !liberty_file.empty())
-			log_cmd_error("Got -lut and -liberty! This two options are exclusive.\n");
+			log_cmd_error("Got -lut and -liberty! These two options are exclusive.\n");
 		if (!constr_file.empty() && liberty_file.empty())
 			log_cmd_error("Got -constr but no -liberty!\n");
 
diff --git a/passes/techmap/abc9.cc b/passes/techmap/abc9.cc
index 27106cc5d..2568a6cd1 100644
--- a/passes/techmap/abc9.cc
+++ b/passes/techmap/abc9.cc
@@ -22,20 +22,6 @@
 // Berkeley Logic Synthesis and Verification Group, ABC: A System for Sequential Synthesis and Verification
 // http://www.eecs.berkeley.edu/~alanmi/abc/
 
-#if 0
-// Based on &flow3 - better QoR but more experimental
-#define ABC_COMMAND_LUT "&st; &ps -l; &sweep -v; &scorr; " \
-						"&st; &if {W}; &save; &st; &syn2; &if {W} -v; &save; &load; "\
-						"&st; &if -g -K 6; &dch -f; &if {W} -v; &save; &load; "\
-						"&st; &if -g -K 6; &synch2; &if {W} -v; &save; &load; "\
-						"&mfs; &ps -l"
-#else
-#define ABC_COMMAND_LUT "&st; &scorr; &sweep; &dc2; &st; &dch -f; &ps; &if {W} {D} -v; &mfs; &ps -l"
-#endif
-
-
-#define ABC_FAST_COMMAND_LUT "&st; &if {W} {D}"
-
 #include "kernel/register.h"
 #include "kernel/sigtools.h"
 #include "kernel/celltypes.h"
@@ -63,22 +49,16 @@ extern "C" int Abc_RealMain(int argc, char *argv[]);
 USING_YOSYS_NAMESPACE
 PRIVATE_NAMESPACE_BEGIN
 
-bool markgroups;
 int map_autoidx;
-SigMap assign_map;
-RTLIL::Module *module;
-
-bool clk_polarity, en_polarity;
-RTLIL::SigSpec clk_sig, en_sig;
 
 inline std::string remap_name(RTLIL::IdString abc9_name)
 {
 	return stringf("$abc$%d$%s", map_autoidx, abc9_name.c_str()+1);
 }
 
-void handle_loops(RTLIL::Design *design)
+void handle_loops(RTLIL::Design *design, RTLIL::Module *module)
 {
-	Pass::call(design, "scc -set_attr abc9_scc_id {}");
+	Pass::call(design, "scc -set_attr abc9_scc_id {} % w:*");
 
 	// For every unique SCC found, (arbitrarily) find the first
 	// cell in the component, and select (and mark) all its output
@@ -94,20 +74,30 @@ void handle_loops(RTLIL::Design *design)
 					if (cell->output(c.first)) {
 						SigBit b = c.second.as_bit();
 						Wire *w = b.wire;
-						log_assert(!w->port_input);
-						w->port_input = true;
-						w = module->wire(stringf("%s.abci", w->name.c_str()));
-						if (!w) {
-							w = module->addWire(stringf("%s.abci", b.wire->name.c_str()), GetSize(b.wire));
-							w->port_output = true;
+						if (w->port_input) {
+							// In this case, hopefully the loop break has been already created
+							// Get the non-prefixed wire
+							Wire *wo = module->wire(stringf("%s.abco", b.wire->name.c_str()));
+							log_assert(wo != nullptr);
+							log_assert(wo->port_output);
+							log_assert(b.offset < GetSize(wo));
+							c.second = RTLIL::SigBit(wo, b.offset);
 						}
 						else {
-							log_assert(w->port_input);
-							log_assert(b.offset < GetSize(w));
+							// Create a new output/input loop break
+							w->port_input = true;
+							w = module->wire(stringf("%s.abco", w->name.c_str()));
+							if (!w) {
+								w = module->addWire(stringf("%s.abco", b.wire->name.c_str()), GetSize(b.wire));
+								w->port_output = true;
+							}
+							else {
+								log_assert(w->port_input);
+								log_assert(b.offset < GetSize(w));
+							}
+							w->set_bool_attribute(ID(abc9_scc_break));
+							c.second = RTLIL::SigBit(w, b.offset);
 						}
-						w->set_bool_attribute(ID(abc9_scc_break));
-						module->swap_names(b.wire, w);
-						c.second = RTLIL::SigBit(w, b.offset);
 					}
 				}
 			}
@@ -243,49 +233,14 @@ struct abc9_output_filter
 	}
 };
 
-void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::string script_file, std::string exe_file,
-		bool cleanup, vector<int> lut_costs, bool dff_mode, std::string clk_str,
-		bool /*keepff*/, std::string delay_target, std::string /*lutin_shared*/, bool fast_mode,
+void abc9_module(RTLIL::Design *design, RTLIL::Module *module, std::string script_file, std::string exe_file,
+		bool cleanup, vector<int> lut_costs, bool dff_mode, std::string delay_target, std::string /*lutin_shared*/, bool fast_mode,
 		bool show_tempdir, std::string box_file, std::string lut_file,
-		std::string wire_delay, const dict<int,IdString> &box_lookup, bool nomfs
+		std::string wire_delay
 )
 {
-	module = current_module;
 	map_autoidx = autoidx++;
 
-	if (clk_str != "$")
-	{
-		clk_polarity = true;
-		clk_sig = RTLIL::SigSpec();
-
-		en_polarity = true;
-		en_sig = RTLIL::SigSpec();
-	}
-
-	if (!clk_str.empty() && clk_str != "$")
-	{
-		if (clk_str.find(',') != std::string::npos) {
-			int pos = clk_str.find(',');
-			std::string en_str = clk_str.substr(pos+1);
-			clk_str = clk_str.substr(0, pos);
-			if (en_str[0] == '!') {
-				en_polarity = false;
-				en_str = en_str.substr(1);
-			}
-			if (module->wires_.count(RTLIL::escape_id(en_str)) != 0)
-				en_sig = assign_map(RTLIL::SigSpec(module->wires_.at(RTLIL::escape_id(en_str)), 0));
-		}
-		if (clk_str[0] == '!') {
-			clk_polarity = false;
-			clk_str = clk_str.substr(1);
-		}
-		if (module->wires_.count(RTLIL::escape_id(clk_str)) != 0)
-			clk_sig = assign_map(RTLIL::SigSpec(module->wires_.at(RTLIL::escape_id(clk_str)), 0));
-	}
-
-	if (dff_mode && clk_sig.empty())
-		log_cmd_error("Clock domain %s not found.\n", clk_str.c_str());
-
 	std::string tempdir_name = "/tmp/yosys-abc-XXXXXX";
 	if (!cleanup)
 		tempdir_name[0] = tempdir_name[4] = '_';
@@ -298,13 +253,13 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 	if (!lut_costs.empty()) {
 		abc9_script += stringf("read_lut %s/lutdefs.txt; ", tempdir_name.c_str());
 		if (!box_file.empty())
-			abc9_script += stringf("read_box -v %s; ", box_file.c_str());
+			abc9_script += stringf("read_box %s; ", box_file.c_str());
 	}
 	else
 	if (!lut_file.empty()) {
 		abc9_script += stringf("read_lut %s; ", lut_file.c_str());
 		if (!box_file.empty())
-			abc9_script += stringf("read_box -v %s; ", box_file.c_str());
+			abc9_script += stringf("read_box %s; ", box_file.c_str());
 	}
 	else
 		log_abort();
@@ -323,20 +278,11 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 		} else
 			abc9_script += stringf("source %s", script_file.c_str());
 	} else if (!lut_costs.empty() || !lut_file.empty()) {
-		//bool all_luts_cost_same = true;
-		//for (int this_cost : lut_costs)
-		//	if (this_cost != lut_costs.front())
-		//		all_luts_cost_same = false;
-		abc9_script += fast_mode ? ABC_FAST_COMMAND_LUT : ABC_COMMAND_LUT;
-		//if (all_luts_cost_same && !fast_mode)
-		//	abc9_script += "; lutpack {S}";
+		abc9_script += fast_mode ? RTLIL::constpad.at("abc9.script.default.fast").substr(1,std::string::npos)
+			: RTLIL::constpad.at("abc9.script.default").substr(1,std::string::npos);
 	} else
 		log_abort();
 
-	//if (script_file.empty() && !delay_target.empty())
-	//	for (size_t pos = abc9_script.find("dretime;"); pos != std::string::npos; pos = abc9_script.find("dretime;", pos+1))
-	//		abc9_script = abc9_script.substr(0, pos) + "dretime; retime -o {D};" + abc9_script.substr(pos+8);
-
 	for (size_t pos = abc9_script.find("{D}"); pos != std::string::npos; pos = abc9_script.find("{D}", pos))
 		abc9_script = abc9_script.substr(0, pos) + delay_target + abc9_script.substr(pos+3);
 
@@ -346,11 +292,26 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 	for (size_t pos = abc9_script.find("{W}"); pos != std::string::npos; pos = abc9_script.find("{W}", pos))
 		abc9_script = abc9_script.substr(0, pos) + wire_delay + abc9_script.substr(pos+3);
 
-	if (nomfs)
-		for (size_t pos = abc9_script.find("&mfs"); pos != std::string::npos; pos = abc9_script.find("&mfs", pos))
-			abc9_script = abc9_script.erase(pos, strlen("&mfs"));
-
-	abc9_script += stringf("; &write %s/output.aig", tempdir_name.c_str());
+	std::string C;
+	if (design->scratchpad.count("abc9.if.C"))
+		C = "-C " + design->scratchpad_get_string("abc9.if.C");
+	for (size_t pos = abc9_script.find("{C}"); pos != std::string::npos; pos = abc9_script.find("{C}", pos))
+		abc9_script = abc9_script.substr(0, pos) + C + abc9_script.substr(pos+3);
+
+	std::string R;
+	if (design->scratchpad.count("abc9.if.R"))
+		R = "-R " + design->scratchpad_get_string("abc9.if.R");
+	for (size_t pos = abc9_script.find("{R}"); pos != std::string::npos; pos = abc9_script.find("{R}", pos))
+		abc9_script = abc9_script.substr(0, pos) + R + abc9_script.substr(pos+3);
+
+	abc9_script += stringf("; &ps -l; &write -n %s/output.aig", tempdir_name.c_str());
+	if (design->scratchpad_get_bool("abc9.verify")) {
+		if (dff_mode)
+			abc9_script += "; &verify -s";
+		else
+			abc9_script += "; &verify";
+	}
+	abc9_script += "; time";
 	abc9_script = add_echos_to_abc9_cmd(abc9_script);
 
 	for (size_t i = 0; i+1 < abc9_script.size(); i++)
@@ -361,45 +322,22 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 	fprintf(f, "%s\n", abc9_script.c_str());
 	fclose(f);
 
-	if (dff_mode || !clk_str.empty())
-	{
-		if (clk_sig.size() == 0)
-			log("No%s clock domain found. Not extracting any FF cells.\n", clk_str.empty() ? "" : " matching");
-		else {
-			log("Found%s %s clock domain: %s", clk_str.empty() ? "" : " matching", clk_polarity ? "posedge" : "negedge", log_signal(clk_sig));
-			if (en_sig.size() != 0)
-				log(", enabled by %s%s", en_polarity ? "" : "!", log_signal(en_sig));
-			log("\n");
-		}
-	}
-
-	bool count_output = false;
-	for (auto port_name : module->ports) {
-		RTLIL::Wire *port_wire = module->wire(port_name);
-		log_assert(port_wire);
-		if (port_wire->port_output) {
-			count_output = true;
-			break;
-		}
-	}
-
 	log_push();
 
-	if (count_output)
-	{
-		design->selection_stack.emplace_back(false);
-		RTLIL::Selection& sel = design->selection_stack.back();
-		sel.select(module);
-
-		handle_loops(design);
+	handle_loops(design, module);
 
-		Pass::call(design, "aigmap");
+	Pass::call(design, "aigmap -select");
 
-		//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);
+	Pass::call(design, stringf("write_xaiger -map %s/input.sym %s/input.xaig", tempdir_name.c_str(), tempdir_name.c_str()));
 
-		Pass::call(design, stringf("write_xaiger -map %s/input.sym %s/input.xaig", tempdir_name.c_str(), tempdir_name.c_str()));
+	int count_outputs = design->scratchpad_get_int("write_xaiger.num_outputs");
+	log("Extracted %d AND gates and %d wires to a netlist network with %d inputs and %d outputs.\n",
+			design->scratchpad_get_int("write_xaiger.num_ands"),
+			design->scratchpad_get_int("write_xaiger.num_wires"),
+			design->scratchpad_get_int("write_xaiger.num_inputs"),
+			count_outputs);
 
+	if (count_outputs > 0) {
 		std::string buffer;
 		std::ifstream ifs;
 #if 0
@@ -414,30 +352,10 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 			reader.parse_xaiger();
 		}
 		ifs.close();
-		Pass::call(design, stringf("write_verilog -noexpr -norename"));
+		Pass::call_on_module(design, design->module(ID($__abc9__)), stringf("write_verilog -noexpr -norename -selected"));
 		design->remove(design->module(ID($__abc9__)));
 #endif
 
-		design->selection_stack.pop_back();
-
-		// Now 'unexpose' those wires by undoing
-		// the expose operation -- remove them from PO/PI
-		// and re-connecting them back together
-		for (auto wire : module->wires()) {
-			auto it = wire->attributes.find(ID(abc9_scc_break));
-			if (it != wire->attributes.end()) {
-				wire->attributes.erase(it);
-				log_assert(wire->port_output);
-				wire->port_output = false;
-				RTLIL::Wire *i_wire = module->wire(wire->name.str() + ".abci");
-				log_assert(i_wire);
-				log_assert(i_wire->port_input);
-				i_wire->port_input = false;
-				module->connect(i_wire, wire);
-			}
-		}
-		module->fixup_ports();
-
 		log_header(design, "Executing ABC9.\n");
 
 		if (!lut_costs.empty()) {
@@ -483,11 +401,11 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 		log_assert(!design->module(ID($__abc9__)));
 
 		AigerReader reader(design, ifs, ID($__abc9__), "" /* clk_name */, buffer.c_str() /* map_filename */, true /* wideports */);
-		reader.parse_xaiger(box_lookup);
+		reader.parse_xaiger();
 		ifs.close();
 
 #if 0
-		Pass::call(design, stringf("write_verilog -noexpr -norename"));
+		Pass::call_on_module(design, design->module(ID($__abc9__)), stringf("write_verilog -noexpr -norename -selected"));
 #endif
 
 		log_header(design, "Re-integrating ABC9 results.\n");
@@ -495,43 +413,30 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 		if (mapped_mod == NULL)
 			log_error("ABC output file does not contain a module `$__abc9__'.\n");
 
-		pool<RTLIL::SigBit> output_bits;
-		for (auto &it : mapped_mod->wires_) {
-			RTLIL::Wire *w = it.second;
-			RTLIL::Wire *remap_wire = module->addWire(remap_name(w->name), GetSize(w));
-			if (markgroups) remap_wire->attributes[ID(abcgroup)] = map_autoidx;
-			if (w->port_output) {
-				RTLIL::Wire *wire = module->wire(w->name);
-				log_assert(wire);
-				for (int i = 0; i < GetSize(w); i++)
-					output_bits.insert({wire, i});
-			}
-		}
-
-		for (auto &it : module->connections_) {
-			auto &signal = it.first;
-			auto bits = signal.bits();
-			for (auto &b : bits)
-				if (output_bits.count(b))
-					b = module->addWire(NEW_ID);
-			signal = std::move(bits);
-		}
+		for (auto w : mapped_mod->wires())
+			module->addWire(remap_name(w->name), GetSize(w));
 
 		dict<IdString, bool> abc9_box;
 		vector<RTLIL::Cell*> boxes;
-		for (const auto &it : module->cells_) {
-			auto cell = it.second;
-			if (cell->type.in(ID($_AND_), ID($_NOT_))) {
+		for (auto cell : module->cells().to_vector()) {
+			if (cell->type.in(ID($_AND_), ID($_NOT_), ID($__ABC9_FF_))) {
 				module->remove(cell);
 				continue;
 			}
+			RTLIL::Module* box_module = design->module(cell->type);
 			auto jt = abc9_box.find(cell->type);
-			if (jt == abc9_box.end()) {
-				RTLIL::Module* box_module = design->module(cell->type);
+			if (jt == abc9_box.end())
 				jt = abc9_box.insert(std::make_pair(cell->type, box_module && box_module->attributes.count(ID(abc9_box_id)))).first;
+			if (jt->second) {
+				if (box_module->get_bool_attribute("\\abc9_flop")) {
+					if (dff_mode)
+						boxes.emplace_back(cell);
+					else
+						box_module->set_bool_attribute("\\abc9_keep", false);
+				}
+				else
+					boxes.emplace_back(cell);
 			}
-			if (jt->second)
-				boxes.emplace_back(cell);
 		}
 
 		dict<SigBit, pool<IdString>> bit_drivers, bit_users;
@@ -540,19 +445,19 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 		dict<SigBit, std::vector<RTLIL::Cell*>> bit2sinks;
 
 		std::map<IdString, int> cell_stats;
-		for (auto c : mapped_mod->cells())
+		for (auto mapped_cell : mapped_mod->cells())
 		{
-			toposort.node(c->name);
+			toposort.node(mapped_cell->name);
 
 			RTLIL::Cell *cell = nullptr;
-			if (c->type == ID($_NOT_)) {
-				RTLIL::SigBit a_bit = c->getPort(ID::A);
-				RTLIL::SigBit y_bit = c->getPort(ID::Y);
-				bit_users[a_bit].insert(c->name);
-				bit_drivers[y_bit].insert(c->name);
+			if (mapped_cell->type == ID($_NOT_)) {
+				RTLIL::SigBit a_bit = mapped_cell->getPort(ID::A);
+				RTLIL::SigBit y_bit = mapped_cell->getPort(ID::Y);
+				bit_users[a_bit].insert(mapped_cell->name);
+				bit_drivers[y_bit].insert(mapped_cell->name);
 
 				if (!a_bit.wire) {
-					c->setPort(ID::Y, module->addWire(NEW_ID));
+					mapped_cell->setPort(ID::Y, module->addWire(NEW_ID));
 					RTLIL::Wire *wire = module->wire(remap_name(y_bit.wire->name));
 					log_assert(wire);
 					module->connect(RTLIL::SigBit(wire, y_bit.offset), State::S1);
@@ -567,16 +472,16 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 						// (TODO: Optimise by not cloning unless will increase depth)
 						RTLIL::IdString driver_name;
 						if (GetSize(a_bit.wire) == 1)
-							driver_name = stringf("%s$lut", a_bit.wire->name.c_str());
+							driver_name = stringf("$lut%s", a_bit.wire->name.c_str());
 						else
-							driver_name = stringf("%s[%d]$lut", a_bit.wire->name.c_str(), a_bit.offset);
+							driver_name = stringf("$lut%s[%d]", a_bit.wire->name.c_str(), a_bit.offset);
 						driver_lut = mapped_mod->cell(driver_name);
 					}
 
 					if (!driver_lut) {
 						// If a driver couldn't be found (could be from PI or box CI)
 						// then implement using a LUT
-						cell = module->addLut(remap_name(stringf("%s$lut", c->name.c_str())),
+						cell = module->addLut(remap_name(stringf("$lut%s", mapped_cell->name.c_str())),
 								RTLIL::SigBit(module->wires_.at(remap_name(a_bit.wire->name)), a_bit.offset),
 								RTLIL::SigBit(module->wires_.at(remap_name(y_bit.wire->name)), y_bit.offset),
 								RTLIL::Const::from_string("01"));
@@ -584,44 +489,46 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 						cell_stats[ID($lut)]++;
 					}
 					else
-						not2drivers[c] = driver_lut;
+						not2drivers[mapped_cell] = driver_lut;
 					continue;
 				}
 				else
 					log_abort();
-				if (cell && markgroups) cell->attributes[ID(abcgroup)] = map_autoidx;
 				continue;
 			}
-			cell_stats[c->type]++;
+			cell_stats[mapped_cell->type]++;
 
 			RTLIL::Cell *existing_cell = nullptr;
-			if (c->type == ID($lut)) {
-				if (GetSize(c->getPort(ID::A)) == 1 && c->getParam(ID(LUT)) == RTLIL::Const::from_string("01")) {
-					SigSpec my_a = module->wires_.at(remap_name(c->getPort(ID::A).as_wire()->name));
-					SigSpec my_y = module->wires_.at(remap_name(c->getPort(ID::Y).as_wire()->name));
+			if (mapped_cell->type.in(ID($lut), ID($__ABC9_FF_))) {
+				if (mapped_cell->type == ID($lut) &&
+						GetSize(mapped_cell->getPort(ID::A)) == 1 &&
+						mapped_cell->getParam(ID(LUT)) == RTLIL::Const::from_string("01")) {
+					SigSpec my_a = module->wires_.at(remap_name(mapped_cell->getPort(ID::A).as_wire()->name));
+					SigSpec my_y = module->wires_.at(remap_name(mapped_cell->getPort(ID::Y).as_wire()->name));
 					module->connect(my_y, my_a);
-					if (markgroups) c->attributes[ID(abcgroup)] = map_autoidx;
 					log_abort();
 					continue;
 				}
-				cell = module->addCell(remap_name(c->name), c->type);
+				cell = module->addCell(remap_name(mapped_cell->name), mapped_cell->type);
 			}
 			else {
-				existing_cell = module->cell(c->name);
+				existing_cell = module->cell(mapped_cell->name);
 				log_assert(existing_cell);
-				cell = module->addCell(remap_name(c->name), c->type);
+				cell = module->addCell(remap_name(mapped_cell->name), mapped_cell->type);
 			}
 
-			if (markgroups) cell->attributes[ID(abcgroup)] = map_autoidx;
 			if (existing_cell) {
 				cell->parameters = existing_cell->parameters;
 				cell->attributes = existing_cell->attributes;
 			}
 			else {
-				cell->parameters = c->parameters;
-				cell->attributes = c->attributes;
+				cell->parameters = mapped_cell->parameters;
+				cell->attributes = mapped_cell->attributes;
 			}
-			for (auto &conn : c->connections()) {
+
+			RTLIL::Module* box_module = design->module(mapped_cell->type);
+			auto abc9_flop = box_module && box_module->get_bool_attribute("\\abc9_flop");
+			for (auto &conn : mapped_cell->connections()) {
 				RTLIL::SigSpec newsig;
 				for (auto c : conn.second.chunks()) {
 					if (c.width == 0)
@@ -633,15 +540,17 @@ void abc9_module(RTLIL::Design *design, RTLIL::Module *current_module, std::stri
 				}
 				cell->setPort(conn.first, newsig);
 
-				if (cell->input(conn.first)) {
-					for (auto i : newsig)
-						bit2sinks[i].push_back(cell);
-					for (auto i : conn.second)
-						bit_users[i].insert(c->name);
+				if (!abc9_flop) {
+					if (cell->input(conn.first)) {
+						for (auto i : newsig)
+							bit2sinks[i].push_back(cell);
+						for (auto i : conn.second)
+							bit_users[i].insert(mapped_cell->name);
+					}
+					if (cell->output(conn.first))
+						for (auto i : conn.second)
+							bit_drivers[i].insert(mapped_cell->name);
 				}
-				if (cell->output(conn.first))
-					for (auto i : conn.second)
-						bit_drivers[i].insert(c->name);
 			}
 		}
 
@@ -781,6 +690,25 @@ clone_lut:
 			}
 		}
 
+		// Now 'unexpose' those wires by undoing
+		// the expose operation -- remove them from PO/PI
+		// and re-connecting them back together
+		for (auto wire : module->wires()) {
+			auto it = wire->attributes.find(ID(abc9_scc_break));
+			if (it != wire->attributes.end()) {
+				wire->attributes.erase(it);
+				log_assert(wire->port_output);
+				wire->port_output = false;
+				std::string name = wire->name.str();
+				RTLIL::Wire *i_wire = module->wire(name.substr(0, GetSize(name) - 5));
+				log_assert(i_wire);
+				log_assert(i_wire->port_input);
+				i_wire->port_input = false;
+				module->connect(i_wire, wire);
+			}
+		}
+		module->fixup_ports();
+
 		//log("ABC RESULTS:        internal signals: %8d\n", int(signal_list.size()) - in_wires - out_wires);
 		log("ABC RESULTS:           input signals: %8d\n", in_wires);
 		log("ABC RESULTS:          output signals: %8d\n", out_wires);
@@ -803,6 +731,51 @@ clone_lut:
 
 struct Abc9Pass : public Pass {
 	Abc9Pass() : Pass("abc9", "use ABC9 for technology mapping") { }
+	void on_register() YS_OVERRIDE
+	{
+		RTLIL::constpad["abc9.script.default"] = "+&scorr; &sweep; &dc2; &dch -f; &ps; &if {C} {W} {D} {R} -v; &mfs";
+		RTLIL::constpad["abc9.script.default.area"] = "+&scorr; &sweep; &dc2; &dch -f; &ps; &if {C} {W} {D} {R} -a -v; &mfs";
+		RTLIL::constpad["abc9.script.default.fast"] = "+&if {C} {W} {D} {R} -v";
+		// Based on ABC's &flow
+		RTLIL::constpad["abc9.script.flow"] = "+&scorr; &sweep;" \
+			"&dch -C 500;" \
+			/* Round 1 */ \
+			/* Map 1 */ "&unmap; &if {C} {W} {D} {R} -v; &save; &load; &mfs;" \
+			"&st; &dsdb;" \
+			/* Map 2 */ "&unmap; &if {C} {W} {D} {R} -v; &save; &load; &mfs;" \
+			"&st; &syn2 -m -R 10; &dsdb;" \
+			"&blut -a -K 6;" \
+			/* Map 3 */ "&unmap; &if {C} {W} {D} {R} -v; &save; &load; &mfs;" \
+			/* Round 2 */ \
+			"&st; &sopb;" \
+			/* Map 1 */ "&unmap; &if {C} {W} {D} {R} -v; &save; &load; &mfs;" \
+			"&st; &dsdb;" \
+			/* Map 2 */ "&unmap; &if {C} {W} {D} {R} -v; &save; &load; &mfs;" \
+			"&st; &syn2 -m -R 10; &dsdb;" \
+			"&blut -a -K 6;" \
+			/* Map 3 */ "&unmap; &if {C} {W} {D} {R} -v; &save; &load; &mfs;" \
+			/* Round 3 */ \
+			/* Map 1 */ "&unmap; &if {C} {W} {D} {R} -v; &save; &load; &mfs;" \
+			"&st; &dsdb;" \
+			/* Map 2 */ "&unmap; &if {C} {W} {D} {R} -v; &save; &load; &mfs;" \
+			"&st; &syn2 -m -R 10; &dsdb;" \
+			"&blut -a -K 6;" \
+			/* Map 3 */ "&unmap; &if {C} {W} {D} {R} -v; &save; &load; &mfs;";
+		// Based on ABC's &flow2
+		RTLIL::constpad["abc9.script.flow2"] = "+&scorr; &sweep;" \
+			/* Comm1 */ "&synch2 -K 6 -C 500; &if -m {C} {W} {D} {R} -v; &mfs "/*"-W 4 -M 500 -C 7000"*/"; &save;"\
+			/* Comm2 */ "&dch -C 500; &if -m {C} {W} {D} {R} -v; &mfs "/*"-W 4 -M 500 -C 7000"*/"; &save;"\
+			"&load; &st; &sopb -R 10 -C 4; " \
+			/* Comm3 */ "&synch2 -K 6 -C 500; &if -m "/*"-E 5"*/" {C} {W} {D} {R} -v; &mfs "/*"-W 4 -M 500 -C 7000"*/"; &save;"\
+			/* Comm2 */ "&dch -C 500; &if -m {C} {W} {D} {R} -v; &mfs "/*"-W 4 -M 500 -C 7000"*/"; &save; "\
+			"&load";
+		// Based on ABC's &flow3
+		RTLIL::constpad["abc9.script.flow3"] = "+&scorr; &sweep;" \
+			"&if {C} {W} {D}; &save; &st; &syn2; &if {C} {W} {D} {R} -v; &save; &load;"\
+			"&st; &if {C} -g -K 6; &dch -f; &if {C} {W} {D} {R} -v; &save; &load;"\
+			"&st; &if {C} -g -K 6; &synch2; &if {C} {W} {D} {R} -v; &save; &load;"\
+			"&mfs";
+	}
 	void help() YS_OVERRIDE
 	{
 		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
@@ -810,7 +783,7 @@ struct Abc9Pass : public Pass {
 		log("    abc9 [options] [selection]\n");
 		log("\n");
 		log("This pass uses the ABC tool [1] for technology mapping of yosys's internal gate\n");
-		log("library to a target architecture.\n");
+		log("library to a target architecture. Only fully-selected modules are supported.\n");
 		log("\n");
 		log("    -exe <command>\n");
 #ifdef ABCEXTERNAL
@@ -830,25 +803,20 @@ struct Abc9Pass : public Pass {
 		log("\n");
 		log("        if no -script parameter is given, the following scripts are used:\n");
 		log("\n");
-		log("        for -lut/-luts (only one LUT size):\n");
-		log("%s\n", fold_abc9_cmd(ABC_COMMAND_LUT /*"; lutpack {S}"*/).c_str());
-		log("\n");
-		log("        for -lut/-luts (different LUT sizes):\n");
-		log("%s\n", fold_abc9_cmd(ABC_COMMAND_LUT).c_str());
+		log("        for -lut/-luts:\n");
+		log("%s\n", fold_abc9_cmd(RTLIL::constpad.at("abc9.script.default").substr(1,std::string::npos)).c_str());
 		log("\n");
 		log("    -fast\n");
 		log("        use different default scripts that are slightly faster (at the cost\n");
 		log("        of output quality):\n");
 		log("\n");
 		log("        for -lut/-luts:\n");
-		log("%s\n", fold_abc9_cmd(ABC_FAST_COMMAND_LUT).c_str());
+		log("%s\n", fold_abc9_cmd(RTLIL::constpad.at("abc9.script.default.fast").substr(1,std::string::npos)).c_str());
 		log("\n");
 		log("    -D <picoseconds>\n");
 		log("        set delay target. the string {D} in the default scripts above is\n");
 		log("        replaced by this option when used, and an empty string otherwise\n");
 		log("        (indicating best possible delay).\n");
-//		log("        This also replaces 'dretime' with 'dretime; retime -o {D}' in the\n");
-//		log("        default scripts above.\n");
 		log("\n");
 //		log("    -S <num>\n");
 //		log("        maximum number of LUT inputs shared.\n");
@@ -870,19 +838,10 @@ struct Abc9Pass : public Pass {
 		log("        generate netlist using luts. Use the specified costs for luts with 1,\n");
 		log("        2, 3, .. inputs.\n");
 		log("\n");
-//		log("    -dff\n");
-//		log("        also pass $_DFF_?_ and $_DFFE_??_ cells through ABC. modules with many\n");
-//		log("        clock domains are automatically partitioned in clock domains and each\n");
-//		log("        domain is passed through ABC independently.\n");
-//		log("\n");
-//		log("    -clk [!]<clock-signal-name>[,[!]<enable-signal-name>]\n");
-//		log("        use only the specified clock domain. this is like -dff, but only FF\n");
-//		log("        cells that belong to the specified clock domain are used.\n");
-//		log("\n");
-//		log("    -keepff\n");
-//		log("        set the \"keep\" attribute on flip-flop output wires. (and thus preserve\n");
-//		log("        them, for example for equivalence checking.)\n");
-//		log("\n");
+		log("    -dff\n");
+		log("        also pass $_ABC9_FF_ cells through to ABC. modules with many clock\n");
+		log("        domains are marked as such and automatically partitioned by ABC.\n");
+		log("\n");
 		log("    -nocleanup\n");
 		log("        when this option is used, the temporary files created by this pass\n");
 		log("        are not removed. this is useful for debugging.\n");
@@ -891,11 +850,6 @@ struct Abc9Pass : public Pass {
 		log("        print the temp dir name in log. usually this is suppressed so that the\n");
 		log("        command output is identical across runs.\n");
 		log("\n");
-		log("    -markgroups\n");
-		log("        set a 'abcgroup' attribute on all objects created by ABC. The value of\n");
-		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("    -box <file>\n");
 		log("        pass this file with box library to ABC. Use with -lut.\n");
 		log("\n");
@@ -903,8 +857,8 @@ struct Abc9Pass : public Pass {
 		log("internally. This is not going to \"run ABC on your design\". It will instead run\n");
 		log("ABC on logic snippets extracted from your design. You will not get any useful\n");
 		log("output when passing an ABC script that writes a file. Instead write your full\n");
-		log("design as BLIF file with write_blif and then load that into ABC externally if\n");
-		log("you want to use ABC to convert your design into another format.\n");
+		log("design as an XAIGER file with `write_xaiger' and then load that into ABC\n");
+		log("externally if you want to use ABC to convert your design into another format.\n");
 		log("\n");
 		log("[1] http://www.eecs.berkeley.edu/~alanmi/abc/\n");
 		log("\n");
@@ -914,8 +868,6 @@ struct Abc9Pass : public Pass {
 		log_header(design, "Executing ABC9 pass (technology mapping using ABC9).\n");
 		log_push();
 
-		assign_map.clear();
-
 #ifdef ABCEXTERNAL
 		std::string exe_file = ABCEXTERNAL;
 #else
@@ -923,11 +875,9 @@ struct Abc9Pass : public Pass {
 #endif
 		std::string script_file, clk_str, box_file, lut_file;
 		std::string delay_target, lutin_shared = "-S 1", wire_delay;
-		bool fast_mode = false, dff_mode = false, keepff = false, cleanup = true;
+		bool fast_mode = false, dff_mode = false, cleanup = true;
 		bool show_tempdir = false;
-		bool nomfs = false;
 		vector<int> lut_costs;
-		markgroups = false;
 
 #if 0
 		cleanup = false;
@@ -941,6 +891,29 @@ struct Abc9Pass : public Pass {
 #endif
 #endif
 
+		// get arguments from scratchpad first, then override by command arguments
+		std::string lut_arg, luts_arg;
+		exe_file = design->scratchpad_get_string("abc9.exe", exe_file /* inherit default value if not set */);
+		script_file = design->scratchpad_get_string("abc9.script", script_file);
+		if (design->scratchpad.count("abc9.D")) {
+			delay_target = "-D " + design->scratchpad_get_string("abc9.D");
+		}
+		lut_arg = design->scratchpad_get_string("abc9.lut", lut_arg);
+		luts_arg = design->scratchpad_get_string("abc9.luts", luts_arg);
+		fast_mode = design->scratchpad_get_bool("abc9.fast", fast_mode);
+		dff_mode = design->scratchpad_get_bool("abc9.dff", dff_mode);
+		cleanup = !design->scratchpad_get_bool("abc9.nocleanup", !cleanup);
+		show_tempdir = design->scratchpad_get_bool("abc9.showtmp", show_tempdir);
+		box_file = design->scratchpad_get_string("abc9.box", box_file);
+		if (design->scratchpad.count("abc9.W")) {
+			wire_delay = "-W " + design->scratchpad_get_string("abc9.W");
+		}
+
+		if (design->scratchpad_get_bool("abc9.debug")) {
+			cleanup = false;
+			show_tempdir = true;
+		}
+
 		size_t argidx;
 		char pwd [PATH_MAX];
 		if (!getcwd(pwd, sizeof(pwd))) {
@@ -955,9 +928,6 @@ struct Abc9Pass : public Pass {
 			}
 			if (arg == "-script" && argidx+1 < args.size()) {
 				script_file = args[++argidx];
-				rewrite_filename(script_file);
-				if (!script_file.empty() && !is_absolute_path(script_file) && script_file[0] != '+')
-					script_file = std::string(pwd) + "/" + script_file;
 				continue;
 			}
 			if (arg == "-D" && argidx+1 < args.size()) {
@@ -969,65 +939,21 @@ struct Abc9Pass : public Pass {
 			//	continue;
 			//}
 			if (arg == "-lut" && argidx+1 < args.size()) {
-				string arg = args[++argidx];
-				size_t pos = arg.find_first_of(':');
-				int lut_mode = 0, lut_mode2 = 0;
-				if (pos != string::npos) {
-					lut_mode = atoi(arg.substr(0, pos).c_str());
-					lut_mode2 = atoi(arg.substr(pos+1).c_str());
-				} else {
-					pos = arg.find_first_of('.');
-					if (pos != string::npos) {
-						lut_file = arg;
-						rewrite_filename(lut_file);
-						if (!lut_file.empty() && !is_absolute_path(lut_file))
-							lut_file = std::string(pwd) + "/" + lut_file;
-					}
-					else {
-						lut_mode = atoi(arg.c_str());
-						lut_mode2 = lut_mode;
-					}
-				}
-				lut_costs.clear();
-				for (int i = 0; i < lut_mode; i++)
-					lut_costs.push_back(1);
-				for (int i = lut_mode; i < lut_mode2; i++)
-					lut_costs.push_back(2 << (i - lut_mode));
+				lut_arg = args[++argidx];
 				continue;
 			}
 			if (arg == "-luts" && argidx+1 < args.size()) {
-				lut_costs.clear();
-				for (auto &tok : split_tokens(args[++argidx], ",")) {
-					auto parts = split_tokens(tok, ":");
-					if (GetSize(parts) == 0 && !lut_costs.empty())
-						lut_costs.push_back(lut_costs.back());
-					else if (GetSize(parts) == 1)
-						lut_costs.push_back(atoi(parts.at(0).c_str()));
-					else if (GetSize(parts) == 2)
-						while (GetSize(lut_costs) < atoi(parts.at(0).c_str()))
-							lut_costs.push_back(atoi(parts.at(1).c_str()));
-					else
-						log_cmd_error("Invalid -luts syntax.\n");
-				}
+				luts_arg = args[++argidx];
 				continue;
 			}
 			if (arg == "-fast") {
 				fast_mode = true;
 				continue;
 			}
-			//if (arg == "-dff") {
-			//	dff_mode = true;
-			//	continue;
-			//}
-			//if (arg == "-clk" && argidx+1 < args.size()) {
-			//	clk_str = args[++argidx];
-			//	dff_mode = true;
-			//	continue;
-			//}
-			//if (arg == "-keepff") {
-			//	keepff = true;
-			//	continue;
-			//}
+			if (arg == "-dff") {
+				dff_mode = true;
+				continue;
+			}
 			if (arg == "-nocleanup") {
 				cleanup = false;
 				continue;
@@ -1036,10 +962,6 @@ struct Abc9Pass : public Pass {
 				show_tempdir = true;
 				continue;
 			}
-			if (arg == "-markgroups") {
-				markgroups = true;
-				continue;
-			}
 			if (arg == "-box" && argidx+1 < args.size()) {
 				box_file = args[++argidx];
 				continue;
@@ -1048,251 +970,125 @@ struct Abc9Pass : public Pass {
 				wire_delay = "-W " + args[++argidx];
 				continue;
 			}
-			if (arg == "-nomfs") {
-				nomfs = true;
-				continue;
-			}
 			break;
 		}
 		extra_args(args, argidx, design);
 
-		// ABC expects a box file for XAIG
-		if (box_file.empty())
-		    box_file = "+/dummy.box";
-
-		rewrite_filename(box_file);
-		if (!box_file.empty() && !is_absolute_path(box_file))
-		    box_file = std::string(pwd) + "/" + box_file;
+		rewrite_filename(script_file);
+		if (!script_file.empty() && !is_absolute_path(script_file) && script_file[0] != '+')
+			script_file = std::string(pwd) + "/" + script_file;
 
-		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);
-
-			RTLIL::Wire *carry_in = nullptr, *carry_out = nullptr;
-			for (auto p : m->ports) {
-				auto w = m->wire(p);
-				log_assert(w);
-				if (w->attributes.count(ID(abc9_carry))) {
-					if (w->port_input) {
-						if (carry_in)
-							log_error("Module '%s' contains more than one 'abc9_carry' input port.\n", log_id(m));
-						carry_in = w;
-					}
-					else if (w->port_output) {
-						if (carry_out)
-							log_error("Module '%s' contains more than one 'abc9_carry' input port.\n", log_id(m));
-						carry_out = w;
-					}
+		// handle -lut / -luts args
+		if (!lut_arg.empty()) {
+			string arg = lut_arg;
+			if (arg.find_first_not_of("0123456789:") == std::string::npos) {
+				size_t pos = arg.find_first_of(':');
+				int lut_mode = 0, lut_mode2 = 0;
+				if (pos != string::npos) {
+					lut_mode = atoi(arg.substr(0, pos).c_str());
+					lut_mode2 = atoi(arg.substr(pos+1).c_str());
+				} else {
+					lut_mode = atoi(arg.c_str());
+					lut_mode2 = lut_mode;
 				}
+				lut_costs.clear();
+				for (int i = 0; i < lut_mode; i++)
+					lut_costs.push_back(1);
+				for (int i = lut_mode; i < lut_mode2; i++)
+					lut_costs.push_back(2 << (i - lut_mode));
 			}
-			if (carry_in || carry_out) {
-				if (carry_in && !carry_out)
-					log_error("Module '%s' contains an 'abc9_carry' input port but no output port.\n", log_id(m));
-				if (!carry_in && carry_out)
-					log_error("Module '%s' contains an 'abc9_carry' output port but no input port.\n", log_id(m));
-				// Make carry_in the last PI, and carry_out the last PO
-				//   since ABC requires it this way
-				auto &ports = m->ports;
-				for (auto it = ports.begin(); it != ports.end(); ) {
-					RTLIL::Wire* w = m->wire(*it);
-					log_assert(w);
-					if (w == carry_in || w == carry_out) {
-						it = ports.erase(it);
-						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);
-					++it;
-				}
-				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 {
+				lut_file = arg;
+				rewrite_filename(lut_file);
+				if (!lut_file.empty() && !is_absolute_path(lut_file) && lut_file[0] != '+')
+					lut_file = std::string(pwd) + "/" + lut_file;
 			}
 		}
-
-		for (auto mod : design->selected_modules())
-		{
-			if (mod->attributes.count(ID(abc9_box_id)))
-				continue;
-
-			if (mod->processes.size() > 0) {
-				log("Skipping module %s as it contains processes.\n", log_id(mod));
-				continue;
+		if (!luts_arg.empty()) {
+			lut_costs.clear();
+			for (auto &tok : split_tokens(luts_arg, ",")) {
+				auto parts = split_tokens(tok, ":");
+				if (GetSize(parts) == 0 && !lut_costs.empty())
+					lut_costs.push_back(lut_costs.back());
+				else if (GetSize(parts) == 1)
+					lut_costs.push_back(atoi(parts.at(0).c_str()));
+				else if (GetSize(parts) == 2)
+					while (GetSize(lut_costs) < atoi(parts.at(0).c_str()))
+						lut_costs.push_back(atoi(parts.at(1).c_str()));
+				else
+					log_cmd_error("Invalid -luts syntax.\n");
 			}
+		}
+
+		// ABC expects a box file for XAIG
+		if (box_file.empty())
+		    box_file = "+/dummy.box";
 
-			assign_map.set(mod);
+		rewrite_filename(box_file);
+		if (!box_file.empty() && !is_absolute_path(box_file) && box_file[0] != '+')
+		    box_file = std::string(pwd) + "/" + box_file;
 
-			if (!dff_mode || !clk_str.empty()) {
-				abc9_module(design, mod, script_file, exe_file, cleanup, lut_costs, dff_mode, clk_str, keepff,
-						delay_target, lutin_shared, fast_mode, show_tempdir,
-						box_file, lut_file, wire_delay, box_lookup, nomfs);
+		SigMap assign_map;
+		CellTypes ct(design);
+		for (auto module : design->selected_modules())
+		{
+			if (module->processes.size() > 0) {
+				log("Skipping module %s as it contains processes.\n", log_id(module));
 				continue;
 			}
+			log_assert(!module->attributes.count(ID(abc9_box_id)));
 
-			CellTypes ct(design);
-
-			std::vector<RTLIL::Cell*> all_cells = mod->selected_cells();
-			std::set<RTLIL::Cell*> unassigned_cells(all_cells.begin(), all_cells.end());
-
-			std::set<RTLIL::Cell*> expand_queue, next_expand_queue;
-			std::set<RTLIL::Cell*> expand_queue_up, next_expand_queue_up;
-			std::set<RTLIL::Cell*> expand_queue_down, next_expand_queue_down;
-
-			typedef tuple<bool, RTLIL::SigSpec, bool, RTLIL::SigSpec> clkdomain_t;
-			std::map<clkdomain_t, std::vector<RTLIL::Cell*>> assigned_cells;
-			std::map<RTLIL::Cell*, clkdomain_t> assigned_cells_reverse;
-
-			std::map<RTLIL::Cell*, std::set<RTLIL::SigBit>> cell_to_bit, cell_to_bit_up, cell_to_bit_down;
-			std::map<RTLIL::SigBit, std::set<RTLIL::Cell*>> bit_to_cell, bit_to_cell_up, bit_to_cell_down;
-
-			for (auto cell : all_cells)
-			{
-				clkdomain_t key;
-
-				for (auto &conn : cell->connections())
-				for (auto bit : conn.second) {
-					bit = assign_map(bit);
-					if (bit.wire != nullptr) {
-						cell_to_bit[cell].insert(bit);
-						bit_to_cell[bit].insert(cell);
-						if (ct.cell_input(cell->type, conn.first)) {
-							cell_to_bit_up[cell].insert(bit);
-							bit_to_cell_down[bit].insert(cell);
-						}
-						if (ct.cell_output(cell->type, conn.first)) {
-							cell_to_bit_down[cell].insert(bit);
-							bit_to_cell_up[bit].insert(cell);
-						}
-					}
-				}
-
-				if (cell->type.in(ID($_DFF_N_), ID($_DFF_P_)))
-				{
-					key = clkdomain_t(cell->type == ID($_DFF_P_), assign_map(cell->getPort(ID(C))), true, RTLIL::SigSpec());
-				}
-				else
-				if (cell->type.in(ID($_DFFE_NN_), ID($_DFFE_NP_), ID($_DFFE_PN_), ID($_DFFE_PP_)))
-				{
-					bool this_clk_pol = cell->type.in(ID($_DFFE_PN_), ID($_DFFE_PP_));
-					bool this_en_pol = cell->type.in(ID($_DFFE_NP_), ID($_DFFE_PP_));
-					key = clkdomain_t(this_clk_pol, assign_map(cell->getPort(ID(C))), this_en_pol, assign_map(cell->getPort(ID(E))));
-				}
-				else
-					continue;
-
-				unassigned_cells.erase(cell);
-				expand_queue.insert(cell);
-				expand_queue_up.insert(cell);
-				expand_queue_down.insert(cell);
+			if (!design->selected_whole_module(module))
+				log_error("Can't handle partially selected module %s!\n", log_id(module));
 
-				assigned_cells[key].push_back(cell);
-				assigned_cells_reverse[cell] = key;
-			}
+			assign_map.set(module);
 
-			while (!expand_queue_up.empty() || !expand_queue_down.empty())
-			{
-				if (!expand_queue_up.empty())
-				{
-					RTLIL::Cell *cell = *expand_queue_up.begin();
-					clkdomain_t key = assigned_cells_reverse.at(cell);
-					expand_queue_up.erase(cell);
-
-					for (auto bit : cell_to_bit_up[cell])
-					for (auto c : bit_to_cell_up[bit])
-						if (unassigned_cells.count(c)) {
-							unassigned_cells.erase(c);
-							next_expand_queue_up.insert(c);
-							assigned_cells[key].push_back(c);
-							assigned_cells_reverse[c] = key;
-							expand_queue.insert(c);
-						}
-				}
+			typedef SigSpec clkdomain_t;
+			dict<clkdomain_t, int> clk_to_mergeability;
 
-				if (!expand_queue_down.empty())
-				{
-					RTLIL::Cell *cell = *expand_queue_down.begin();
-					clkdomain_t key = assigned_cells_reverse.at(cell);
-					expand_queue_down.erase(cell);
-
-					for (auto bit : cell_to_bit_down[cell])
-					for (auto c : bit_to_cell_down[bit])
-						if (unassigned_cells.count(c)) {
-							unassigned_cells.erase(c);
-							next_expand_queue_up.insert(c);
-							assigned_cells[key].push_back(c);
-							assigned_cells_reverse[c] = key;
-							expand_queue.insert(c);
-						}
-				}
+			if (dff_mode)
+				for (auto cell : module->cells()) {
+					if (cell->type != "$__ABC9_FF_")
+						continue;
 
-				if (expand_queue_up.empty() && expand_queue_down.empty()) {
-					expand_queue_up.swap(next_expand_queue_up);
-					expand_queue_down.swap(next_expand_queue_down);
+					Wire *abc9_clock_wire = module->wire(stringf("%s.clock", cell->name.c_str()));
+					if (abc9_clock_wire == NULL)
+						log_error("'%s.clock' is not a wire present in module '%s'.\n", cell->name.c_str(), log_id(module));
+					SigSpec abc9_clock = assign_map(abc9_clock_wire);
+
+					clkdomain_t key(abc9_clock);
+
+					auto r = clk_to_mergeability.insert(std::make_pair(abc9_clock, clk_to_mergeability.size() + 1));
+					auto r2 YS_ATTRIBUTE(unused) = cell->attributes.insert(std::make_pair(ID(abc9_mergeability), r.first->second));
+					log_assert(r2.second);
+
+					Wire *abc9_init_wire = module->wire(stringf("%s.init", cell->name.c_str()));
+					if (abc9_init_wire == NULL)
+						log_error("'%s.init' is not a wire present in module '%s'.\n", cell->name.c_str(), log_id(module));
+					log_assert(GetSize(abc9_init_wire) == 1);
+					SigSpec abc9_init = assign_map(abc9_init_wire);
+					if (!abc9_init.is_fully_const())
+						log_error("'%s.init' is not a constant wire present in module '%s'.\n", cell->name.c_str(), log_id(module));
+					if (abc9_init == State::S1)
+						log_error("'%s.init' in module '%s' has value 1'b1 which is not supported by 'abc9 -dff'.\n", cell->name.c_str(), log_id(module));
+					r2 = cell->attributes.insert(std::make_pair(ID(abc9_init), abc9_init.as_const()));
+					log_assert(r2.second);
 				}
-			}
-
-			while (!expand_queue.empty())
-			{
-				RTLIL::Cell *cell = *expand_queue.begin();
-				clkdomain_t key = assigned_cells_reverse.at(cell);
-				expand_queue.erase(cell);
-
-				for (auto bit : cell_to_bit.at(cell)) {
-					for (auto c : bit_to_cell[bit])
-						if (unassigned_cells.count(c)) {
-							unassigned_cells.erase(c);
-							next_expand_queue.insert(c);
-							assigned_cells[key].push_back(c);
-							assigned_cells_reverse[c] = key;
-						}
-					bit_to_cell[bit].clear();
+			else
+				for (auto cell : module->cells()) {
+					auto inst_module = design->module(cell->type);
+					if (!inst_module || !inst_module->get_bool_attribute("\\abc9_flop"))
+						continue;
+					cell->set_bool_attribute("\\abc9_keep");
 				}
 
-				if (expand_queue.empty())
-					expand_queue.swap(next_expand_queue);
-			}
-
-			clkdomain_t key(true, RTLIL::SigSpec(), true, RTLIL::SigSpec());
-			for (auto cell : unassigned_cells) {
-				assigned_cells[key].push_back(cell);
-				assigned_cells_reverse[cell] = key;
-			}
-
-			log_header(design, "Summary of detected clock domains:\n");
-			for (auto &it : assigned_cells)
-				log("  %d cells in clk=%s%s, en=%s%s\n", GetSize(it.second),
-						std::get<0>(it.first) ? "" : "!", log_signal(std::get<1>(it.first)),
-						std::get<2>(it.first) ? "" : "!", log_signal(std::get<3>(it.first)));
-
-			for (auto &it : assigned_cells) {
-				clk_polarity = std::get<0>(it.first);
-				clk_sig = assign_map(std::get<1>(it.first));
-				en_polarity = std::get<2>(it.first);
-				en_sig = assign_map(std::get<3>(it.first));
-				abc9_module(design, mod, script_file, exe_file, cleanup, lut_costs, !clk_sig.empty(), "$",
-						keepff, delay_target, lutin_shared, fast_mode, show_tempdir,
-						box_file, lut_file, wire_delay, box_lookup, nomfs);
-				assign_map.set(mod);
-			}
+			design->selected_active_module = module->name.str();
+			abc9_module(design, module, script_file, exe_file, cleanup, lut_costs, dff_mode,
+					delay_target, lutin_shared, fast_mode, show_tempdir,
+					box_file, lut_file, wire_delay);
+			design->selected_active_module.clear();
 		}
 
-		assign_map.clear();
-
 		log_pop();
 	}
 } Abc9Pass;
diff --git a/passes/techmap/clkbufmap.cc b/passes/techmap/clkbufmap.cc
index 246932d81..b9cd68883 100644
--- a/passes/techmap/clkbufmap.cc
+++ b/passes/techmap/clkbufmap.cc
@@ -115,6 +115,8 @@ struct ClkbufmapPass : public Pass {
 		// Cell type, port name, bit index.
 		pool<pair<IdString, pair<IdString, int>>> sink_ports;
 		pool<pair<IdString, pair<IdString, int>>> buf_ports;
+		dict<pair<IdString, pair<IdString, int>>, pair<IdString, int>> inv_ports_out;
+		dict<pair<IdString, pair<IdString, int>>, pair<IdString, int>> inv_ports_in;
 
 		// Process submodules before module using them.
 		std::vector<Module *> modules_sorted;
@@ -133,6 +135,14 @@ struct ClkbufmapPass : public Pass {
 					if (wire->get_bool_attribute("\\clkbuf_sink"))
 						for (int i = 0; i < GetSize(wire); i++)
 							sink_ports.insert(make_pair(module->name, make_pair(wire->name, i)));
+					auto it = wire->attributes.find("\\clkbuf_inv");
+					if (it != wire->attributes.end()) {
+						IdString in_name = RTLIL::escape_id(it->second.decode_string());
+						for (int i = 0; i < GetSize(wire); i++) {
+							inv_ports_out[make_pair(module->name, make_pair(wire->name, i))] = make_pair(in_name, i);
+							inv_ports_in[make_pair(module->name, make_pair(in_name, i))] = make_pair(wire->name, i);
+						}
+					}
 				}
 				continue;
 			}
@@ -157,6 +167,37 @@ struct ClkbufmapPass : public Pass {
 				if (buf_ports.count(make_pair(cell->type, make_pair(port.first, i))))
 					buf_wire_bits.insert(sigmap(port.second[i]));
 
+			// Third, propagate tags through inverters.
+			bool retry = true;
+			while (retry) {
+				retry = false;
+				for (auto cell : module->cells())
+				for (auto port : cell->connections())
+				for (int i = 0; i < port.second.size(); i++) {
+					auto it = inv_ports_out.find(make_pair(cell->type, make_pair(port.first, i)));
+					auto bit = sigmap(port.second[i]);
+					// If output of an inverter is connected to a sink, mark it as buffered,
+					// and request a buffer on the inverter's input instead.
+					if (it != inv_ports_out.end() && !buf_wire_bits.count(bit) && sink_wire_bits.count(bit)) {
+						buf_wire_bits.insert(bit);
+						auto other_bit = sigmap(cell->getPort(it->second.first)[it->second.second]);
+						sink_wire_bits.insert(other_bit);
+						retry = true;
+					}
+					// If input of an inverter is marked as already-buffered,
+					// mark its output already-buffered as well.
+					auto it2 = inv_ports_in.find(make_pair(cell->type, make_pair(port.first, i)));
+					if (it2 != inv_ports_in.end() && buf_wire_bits.count(bit)) {
+						auto other_bit = sigmap(cell->getPort(it2->second.first)[it2->second.second]);
+						if (!buf_wire_bits.count(other_bit)) {
+							buf_wire_bits.insert(other_bit);
+							retry = true;
+						}
+					}
+
+				}
+			};
+
 			// Collect all driven bits.
 			for (auto cell : module->cells())
 			for (auto port : cell->connections())
diff --git a/passes/techmap/iopadmap.cc b/passes/techmap/iopadmap.cc
index c868b9a87..531ac2b99 100644
--- a/passes/techmap/iopadmap.cc
+++ b/passes/techmap/iopadmap.cc
@@ -87,11 +87,11 @@ struct IopadmapPass : public Pass {
 	{
 		log_header(design, "Executing IOPADMAP pass (mapping inputs/outputs to IO-PAD cells).\n");
 
-		std::string inpad_celltype, inpad_portname, inpad_portname2;
-		std::string outpad_celltype, outpad_portname, outpad_portname2;
-		std::string inoutpad_celltype, inoutpad_portname, inoutpad_portname2;
-		std::string toutpad_celltype, toutpad_portname, toutpad_portname2, toutpad_portname3;
-		std::string tinoutpad_celltype, tinoutpad_portname, tinoutpad_portname2, tinoutpad_portname3, tinoutpad_portname4;
+		std::string inpad_celltype, inpad_portname_o, inpad_portname_pad;
+		std::string outpad_celltype, outpad_portname_i, outpad_portname_pad;
+		std::string inoutpad_celltype, inoutpad_portname_io, inoutpad_portname_pad;
+		std::string toutpad_celltype, toutpad_portname_oe, toutpad_portname_i, toutpad_portname_pad;
+		std::string tinoutpad_celltype, tinoutpad_portname_oe, tinoutpad_portname_o, tinoutpad_portname_i, tinoutpad_portname_pad;
 		std::string widthparam, nameparam;
 		pool<pair<IdString, IdString>> ignore;
 		bool flag_bits = false;
@@ -102,35 +102,35 @@ struct IopadmapPass : public Pass {
 			std::string arg = args[argidx];
 			if (arg == "-inpad" && argidx+2 < args.size()) {
 				inpad_celltype = args[++argidx];
-				inpad_portname = args[++argidx];
-				split_portname_pair(inpad_portname, inpad_portname2);
+				inpad_portname_o = args[++argidx];
+				split_portname_pair(inpad_portname_o, inpad_portname_pad);
 				continue;
 			}
 			if (arg == "-outpad" && argidx+2 < args.size()) {
 				outpad_celltype = args[++argidx];
-				outpad_portname = args[++argidx];
-				split_portname_pair(outpad_portname, outpad_portname2);
+				outpad_portname_i = args[++argidx];
+				split_portname_pair(outpad_portname_i, outpad_portname_pad);
 				continue;
 			}
 			if (arg == "-inoutpad" && argidx+2 < args.size()) {
 				inoutpad_celltype = args[++argidx];
-				inoutpad_portname = args[++argidx];
-				split_portname_pair(inoutpad_portname, inoutpad_portname2);
+				inoutpad_portname_io = args[++argidx];
+				split_portname_pair(inoutpad_portname_io, inoutpad_portname_pad);
 				continue;
 			}
 			if (arg == "-toutpad" && argidx+2 < args.size()) {
 				toutpad_celltype = args[++argidx];
-				toutpad_portname = args[++argidx];
-				split_portname_pair(toutpad_portname, toutpad_portname2);
-				split_portname_pair(toutpad_portname2, toutpad_portname3);
+				toutpad_portname_oe = args[++argidx];
+				split_portname_pair(toutpad_portname_oe, toutpad_portname_i);
+				split_portname_pair(toutpad_portname_i, toutpad_portname_pad);
 				continue;
 			}
 			if (arg == "-tinoutpad" && argidx+2 < args.size()) {
 				tinoutpad_celltype = args[++argidx];
-				tinoutpad_portname = args[++argidx];
-				split_portname_pair(tinoutpad_portname, tinoutpad_portname2);
-				split_portname_pair(tinoutpad_portname2, tinoutpad_portname3);
-				split_portname_pair(tinoutpad_portname3, tinoutpad_portname4);
+				tinoutpad_portname_oe = args[++argidx];
+				split_portname_pair(tinoutpad_portname_oe, tinoutpad_portname_o);
+				split_portname_pair(tinoutpad_portname_o, tinoutpad_portname_i);
+				split_portname_pair(tinoutpad_portname_i, tinoutpad_portname_pad);
 				continue;
 			}
 			if (arg == "-ignore" && argidx+2 < args.size()) {
@@ -161,16 +161,16 @@ struct IopadmapPass : public Pass {
 		}
 		extra_args(args, argidx, design);
 
-		if (!inpad_portname2.empty())
-			ignore.insert(make_pair(RTLIL::escape_id(inpad_celltype), RTLIL::escape_id(inpad_portname2)));
-		if (!outpad_portname2.empty())
-			ignore.insert(make_pair(RTLIL::escape_id(outpad_celltype), RTLIL::escape_id(outpad_portname2)));
-		if (!inoutpad_portname2.empty())
-			ignore.insert(make_pair(RTLIL::escape_id(inoutpad_celltype), RTLIL::escape_id(inoutpad_portname2)));
-		if (!toutpad_portname3.empty())
-			ignore.insert(make_pair(RTLIL::escape_id(toutpad_celltype), RTLIL::escape_id(toutpad_portname3)));
-		if (!tinoutpad_portname4.empty())
-			ignore.insert(make_pair(RTLIL::escape_id(tinoutpad_celltype), RTLIL::escape_id(tinoutpad_portname4)));
+		if (!inpad_portname_pad.empty())
+			ignore.insert(make_pair(RTLIL::escape_id(inpad_celltype), RTLIL::escape_id(inpad_portname_pad)));
+		if (!outpad_portname_pad.empty())
+			ignore.insert(make_pair(RTLIL::escape_id(outpad_celltype), RTLIL::escape_id(outpad_portname_pad)));
+		if (!inoutpad_portname_pad.empty())
+			ignore.insert(make_pair(RTLIL::escape_id(inoutpad_celltype), RTLIL::escape_id(inoutpad_portname_pad)));
+		if (!toutpad_portname_pad.empty())
+			ignore.insert(make_pair(RTLIL::escape_id(toutpad_celltype), RTLIL::escape_id(toutpad_portname_pad)));
+		if (!tinoutpad_portname_pad.empty())
+			ignore.insert(make_pair(RTLIL::escape_id(tinoutpad_celltype), RTLIL::escape_id(tinoutpad_portname_pad)));
 
 		for (auto module : design->modules())
 			if (module->get_blackbox_attribute())
@@ -180,148 +180,130 @@ struct IopadmapPass : public Pass {
 
 		for (auto module : design->selected_modules())
 		{
-			dict<IdString, pool<int>> skip_wires;
 			pool<SigBit> skip_wire_bits;
-			SigMap sigmap(module);
+			dict<Wire *, dict<int, pair<Cell *, IdString>>> rewrite_bits;
 
 			for (auto cell : module->cells())
 			for (auto port : cell->connections())
 				if (ignore.count(make_pair(cell->type, port.first)))
-					for (auto bit : sigmap(port.second))
+					for (auto bit : port.second)
 						skip_wire_bits.insert(bit);
 
 			if (!toutpad_celltype.empty() || !tinoutpad_celltype.empty())
 			{
-				dict<SigBit, pair<IdString, pool<IdString>>> tbuf_bits;
-				pool<pair<IdString, IdString>> norewrites;
-				SigMap rewrites;
+				dict<SigBit, Cell *> tbuf_bits;
+				pool<SigBit> driven_bits;
 
+				// Gather tristate buffers and always-on drivers.
 				for (auto cell : module->cells())
 					if (cell->type == ID($_TBUF_)) {
-						SigBit bit = sigmap(cell->getPort(ID::Y).as_bit());
-						tbuf_bits[bit].first = cell->name;
+						SigBit bit = cell->getPort(ID::Y).as_bit();
+						tbuf_bits[bit] = cell;
+					} else {
+						for (auto port : cell->connections())
+							if (!cell->known() || cell->output(port.first))
+								for (auto bit : port.second)
+									driven_bits.insert(bit);
 					}
 
-				for (auto cell : module->cells())
-				for (auto port : cell->connections())
-				for (auto bit : sigmap(port.second))
-					if (tbuf_bits.count(bit))
-						tbuf_bits.at(bit).second.insert(cell->name);
+				// If a wire is a target of an assignment, it is driven, unless the source is 'z.
+				for (auto &conn : module->connections())
+					for (int i = 0; i < GetSize(conn.first); i++) {
+						SigBit dstbit = conn.first[i];
+						SigBit srcbit = conn.second[i];
+						if (!srcbit.wire && srcbit.data == State::Sz)
+							continue;
+						driven_bits.insert(dstbit);
+					}
 
 				for (auto wire : module->selected_wires())
 				{
 					if (!wire->port_output)
 						continue;
 
+					// Don't handle inout ports if we have no suitable buffer type.
+					if (wire->port_input && tinoutpad_celltype.empty())
+						continue;
+
+					// likewise for output ports.
+					if (!wire->port_input && toutpad_celltype.empty())
+						continue;
+
 					for (int i = 0; i < GetSize(wire); i++)
 					{
 						SigBit wire_bit(wire, i);
-						SigBit mapped_wire_bit = sigmap(wire_bit);
-
-						if (tbuf_bits.count(mapped_wire_bit) == 0)
-							continue;
-
-						if (skip_wire_bits.count(mapped_wire_bit))
-							continue;
-
-						auto &tbuf_cache = tbuf_bits.at(mapped_wire_bit);
-						Cell *tbuf_cell = module->cell(tbuf_cache.first);
+						Cell *tbuf_cell = nullptr;
 
-						if (tbuf_cell == nullptr)
+						if (skip_wire_bits.count(wire_bit))
 							continue;
 
-						SigBit en_sig = tbuf_cell->getPort(ID(E)).as_bit();
-						SigBit data_sig = tbuf_cell->getPort(ID::A).as_bit();
+						if (tbuf_bits.count(wire_bit))
+							tbuf_cell = tbuf_bits.at(wire_bit);
+
+						SigBit en_sig;
+						SigBit data_sig;
+						bool is_driven = driven_bits.count(wire_bit);
+
+						if (tbuf_cell != nullptr) {
+							// Found a tristate buffer — use it.
+							en_sig = tbuf_cell->getPort(ID(E)).as_bit();
+							data_sig = tbuf_cell->getPort(ID::A).as_bit();
+						} else if (is_driven) {
+							// No tristate buffer, but an always-on driver is present.
+							// If this is an inout port, we're creating a tinoutpad
+							// anyway, just with a constant 1 as enable.
+							if (!wire->port_input)
+								continue;
+							en_sig = SigBit(State::S1);
+							data_sig = wire_bit;
+						} else {
+							// No driver on a wire.  Create a tristate pad with always-0
+							// enable.
+							en_sig = SigBit(State::S0);
+							data_sig = SigBit(State::Sx);
+						}
 
-						if (wire->port_input && !tinoutpad_celltype.empty())
+						if (wire->port_input)
 						{
 							log("Mapping port %s.%s[%d] using %s.\n", log_id(module), log_id(wire), i, tinoutpad_celltype.c_str());
 
 							Cell *cell = module->addCell(NEW_ID, RTLIL::escape_id(tinoutpad_celltype));
-							Wire *owire = module->addWire(NEW_ID);
 
-							cell->setPort(RTLIL::escape_id(tinoutpad_portname), en_sig);
-							cell->setPort(RTLIL::escape_id(tinoutpad_portname2), owire);
-							cell->setPort(RTLIL::escape_id(tinoutpad_portname3), data_sig);
-							cell->setPort(RTLIL::escape_id(tinoutpad_portname4), wire_bit);
+							cell->setPort(RTLIL::escape_id(tinoutpad_portname_oe), en_sig);
 							cell->attributes[ID::keep] = RTLIL::Const(1);
 
-							for (auto cn : tbuf_cache.second) {
-								auto c = module->cell(cn);
-								if (c == nullptr)
-									continue;
-								for (auto port : c->connections()) {
-									SigSpec sig = port.second;
-									bool newsig = false;
-									for (auto &bit : sig)
-										if (sigmap(bit) == mapped_wire_bit) {
-											bit = owire;
-											newsig = true;
-										}
-									if (newsig)
-										c->setPort(port.first, sig);
-								}
+							if (tbuf_cell) {
+								module->remove(tbuf_cell);
+								cell->setPort(RTLIL::escape_id(tinoutpad_portname_o), wire_bit);
+								cell->setPort(RTLIL::escape_id(tinoutpad_portname_i), data_sig);
+							} else if (is_driven) {
+								cell->setPort(RTLIL::escape_id(tinoutpad_portname_i), wire_bit);
+							} else {
+								cell->setPort(RTLIL::escape_id(tinoutpad_portname_o), wire_bit);
+								cell->setPort(RTLIL::escape_id(tinoutpad_portname_i), data_sig);
 							}
-
-
-							module->remove(tbuf_cell);
-							skip_wires[wire->name].insert(i);
-
-							norewrites.insert(make_pair(cell->name, RTLIL::escape_id(tinoutpad_portname4)));
-							rewrites.add(sigmap(wire_bit), owire);
-							continue;
-						}
-
-						if (!wire->port_input && !toutpad_celltype.empty())
-						{
+							skip_wire_bits.insert(wire_bit);
+							if (!tinoutpad_portname_pad.empty())
+								rewrite_bits[wire][i] = make_pair(cell, RTLIL::escape_id(tinoutpad_portname_pad));
+						} else {
 							log("Mapping port %s.%s[%d] using %s.\n", log_id(module), log_id(wire), i, toutpad_celltype.c_str());
 
 							Cell *cell = module->addCell(NEW_ID, RTLIL::escape_id(toutpad_celltype));
 
-							cell->setPort(RTLIL::escape_id(toutpad_portname), en_sig);
-							cell->setPort(RTLIL::escape_id(toutpad_portname2), data_sig);
-							cell->setPort(RTLIL::escape_id(toutpad_portname3), wire_bit);
+							cell->setPort(RTLIL::escape_id(toutpad_portname_oe), en_sig);
+							cell->setPort(RTLIL::escape_id(toutpad_portname_i), data_sig);
 							cell->attributes[ID::keep] = RTLIL::Const(1);
 
-							for (auto cn : tbuf_cache.second) {
-								auto c = module->cell(cn);
-								if (c == nullptr)
-									continue;
-								for (auto port : c->connections()) {
-									SigSpec sig = port.second;
-									bool newsig = false;
-									for (auto &bit : sig)
-										if (sigmap(bit) == mapped_wire_bit) {
-											bit = data_sig;
-											newsig = true;
-										}
-									if (newsig)
-										c->setPort(port.first, sig);
-								}
+							if (tbuf_cell) {
+								module->remove(tbuf_cell);
+								module->connect(wire_bit, data_sig);
 							}
-
-							module->remove(tbuf_cell);
-							skip_wires[wire->name].insert(i);
-							continue;
+							skip_wire_bits.insert(wire_bit);
+							if (!toutpad_portname_pad.empty())
+								rewrite_bits[wire][i] = make_pair(cell, RTLIL::escape_id(toutpad_portname_pad));
 						}
 					}
 				}
-
-				if (GetSize(norewrites))
-				{
-					for (auto cell : module->cells())
-					for (auto port : cell->connections())
-					{
-						if (norewrites.count(make_pair(cell->name, port.first)))
-							continue;
-
-						SigSpec orig_sig = sigmap(port.second);
-						SigSpec new_sig = rewrites(orig_sig);
-
-						if (orig_sig != new_sig)
-							cell->setPort(port.first, new_sig);
-					}
-				}
 			}
 
 			for (auto wire : module->selected_wires())
@@ -329,17 +311,11 @@ struct IopadmapPass : public Pass {
 				if (!wire->port_id)
 					continue;
 
-				std::string celltype, portname, portname2;
+				std::string celltype, portname_int, portname_pad;
 				pool<int> skip_bit_indices;
 
-				if (skip_wires.count(wire->name)) {
-					if (!flag_bits)
-						continue;
-					skip_bit_indices = skip_wires.at(wire->name);
-				}
-
 				for (int i = 0; i < GetSize(wire); i++)
-					if (skip_wire_bits.count(sigmap(SigBit(wire, i))))
+					if (skip_wire_bits.count(SigBit(wire, i)))
 						skip_bit_indices.insert(i);
 
 				if (GetSize(wire) == GetSize(skip_bit_indices))
@@ -351,8 +327,8 @@ struct IopadmapPass : public Pass {
 						continue;
 					}
 					celltype = inpad_celltype;
-					portname = inpad_portname;
-					portname2 = inpad_portname2;
+					portname_int = inpad_portname_o;
+					portname_pad = inpad_portname_pad;
 				} else
 				if (!wire->port_input && wire->port_output) {
 					if (outpad_celltype.empty()) {
@@ -360,8 +336,8 @@ struct IopadmapPass : public Pass {
 						continue;
 					}
 					celltype = outpad_celltype;
-					portname = outpad_portname;
-					portname2 = outpad_portname2;
+					portname_int = outpad_portname_i;
+					portname_pad = outpad_portname_pad;
 				} else
 				if (wire->port_input && wire->port_output) {
 					if (inoutpad_celltype.empty()) {
@@ -369,8 +345,8 @@ struct IopadmapPass : public Pass {
 						continue;
 					}
 					celltype = inoutpad_celltype;
-					portname = inoutpad_portname;
-					portname2 = inoutpad_portname2;
+					portname_int = inoutpad_portname_io;
+					portname_pad = inoutpad_portname_pad;
 				} else
 					log_abort();
 
@@ -381,29 +357,20 @@ struct IopadmapPass : public Pass {
 
 				log("Mapping port %s.%s using %s.\n", RTLIL::id2cstr(module->name), RTLIL::id2cstr(wire->name), celltype.c_str());
 
-				RTLIL::Wire *new_wire = NULL;
-				if (!portname2.empty()) {
-					new_wire = module->addWire(NEW_ID, wire);
-					module->swap_names(new_wire, wire);
-					wire->attributes.clear();
-				}
-
 				if (flag_bits)
 				{
 					for (int i = 0; i < wire->width; i++)
 					{
-						if (skip_bit_indices.count(i)) {
-							if (wire->port_output)
-								module->connect(SigSpec(new_wire, i), SigSpec(wire, i));
-							else
-								module->connect(SigSpec(wire, i), SigSpec(new_wire, i));
+						if (skip_bit_indices.count(i))
 							continue;
-						}
+
+						SigBit wire_bit(wire, i);
 
 						RTLIL::Cell *cell = module->addCell(NEW_ID, RTLIL::escape_id(celltype));
-						cell->setPort(RTLIL::escape_id(portname), RTLIL::SigSpec(wire, i));
-						if (!portname2.empty())
-							cell->setPort(RTLIL::escape_id(portname2), RTLIL::SigSpec(new_wire, i));
+						cell->setPort(RTLIL::escape_id(portname_int), wire_bit);
+
+						if (!portname_pad.empty())
+							rewrite_bits[wire][i] = make_pair(cell, RTLIL::escape_id(portname_pad));
 						if (!widthparam.empty())
 							cell->parameters[RTLIL::escape_id(widthparam)] = RTLIL::Const(1);
 						if (!nameparam.empty())
@@ -414,9 +381,15 @@ struct IopadmapPass : public Pass {
 				else
 				{
 					RTLIL::Cell *cell = module->addCell(NEW_ID, RTLIL::escape_id(celltype));
-					cell->setPort(RTLIL::escape_id(portname), RTLIL::SigSpec(wire));
-					if (!portname2.empty())
-						cell->setPort(RTLIL::escape_id(portname2), RTLIL::SigSpec(new_wire));
+					cell->setPort(RTLIL::escape_id(portname_int), RTLIL::SigSpec(wire));
+
+					if (!portname_pad.empty()) {
+						RTLIL::Wire *new_wire = NULL;
+						new_wire = module->addWire(NEW_ID, wire);
+						module->swap_names(new_wire, wire);
+						wire->attributes.clear();
+						cell->setPort(RTLIL::escape_id(portname_pad), RTLIL::SigSpec(new_wire));
+					}
 					if (!widthparam.empty())
 						cell->parameters[RTLIL::escape_id(widthparam)] = RTLIL::Const(wire->width);
 					if (!nameparam.empty())
@@ -424,6 +397,32 @@ struct IopadmapPass : public Pass {
 					cell->attributes[ID::keep] = RTLIL::Const(1);
 				}
 
+				if (!rewrite_bits.count(wire)) {
+					wire->port_id = 0;
+					wire->port_input = false;
+					wire->port_output = false;
+				}
+			}
+
+			for (auto &it : rewrite_bits) {
+				RTLIL::Wire *wire = it.first;
+				RTLIL::Wire *new_wire = module->addWire(NEW_ID, wire);
+				module->swap_names(new_wire, wire);
+				wire->attributes.clear();
+				for (int i = 0; i < wire->width; i++)
+				{
+					SigBit wire_bit(wire, i);
+					if (!it.second.count(i)) {
+						if (wire->port_output)
+							module->connect(SigSpec(new_wire, i), SigSpec(wire, i));
+						else
+							module->connect(SigSpec(wire, i), SigSpec(new_wire, i));
+					} else {
+						auto &new_conn = it.second.at(i);
+						new_conn.first->setPort(new_conn.second, RTLIL::SigSpec(new_wire, i));
+					}
+				}
+
 				wire->port_id = 0;
 				wire->port_input = false;
 				wire->port_output = false;