Merge branch 'master' of https://github.com/cliffordwolf/yosys

13 files changed, 451 insertions, 12 deletions

diff --git a/frontends/verilog/verilog_frontend.cc b/frontends/verilog/verilog_frontend.cc
index dcccb4e9a..142e5e727 100644
--- a/frontends/verilog/verilog_frontend.cc
+++ b/frontends/verilog/verilog_frontend.cc
@@ -38,6 +38,9 @@ using namespace VERILOG_FRONTEND;
 
 // use the Verilog bison/flex parser to generate an AST and use AST::process() to convert it to RTLIL
 
+static std::vector<std::string> verilog_defaults;
+static std::list<std::vector<std::string>> verilog_defaults_stack;
+
 struct VerilogFrontend : public Frontend {
 	VerilogFrontend() : Frontend("verilog", "read modules from verilog file") { }
 	virtual void help()
@@ -108,6 +111,9 @@ struct VerilogFrontend : public Frontend {
 		log("        add 'dir' to the directories which are used when searching include\n");
 		log("        files\n");
 		log("\n");
+		log("The command 'verilog_defaults' can be used to register default options for\n");
+		log("subsequent calls to 'read_verilog'.\n");
+		log("\n");
 	}
 	virtual void execute(FILE *&f, std::string filename, std::vector<std::string> args, RTLIL::Design *design)
 	{
@@ -128,6 +134,8 @@ struct VerilogFrontend : public Frontend {
 
 		log_header("Executing Verilog-2005 frontend.\n");
 
+		args.insert(args.begin()+1, verilog_defaults.begin(), verilog_defaults.end());
+
 		size_t argidx;
 		for (argidx = 1; argidx < args.size(); argidx++) {
 			std::string arg = args[argidx];
@@ -248,3 +256,61 @@ void frontend_verilog_yyerror(char const *fmt, ...)
 	exit(1);
 }
 
+struct VerilogDefaults : public Pass {
+	VerilogDefaults() : Pass("verilog_defaults", "set default options for read_verilog") { }
+	virtual void help()
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    verilog_defaults -add [options]\n");
+		log("\n");
+		log("Add the sepcified options to the list of default options to read_verilog.\n");
+		log("\n");
+		log("\n");
+		log("    verilog_defaults -clear");
+		log("\n");
+		log("Clear the list of verilog default options.\n");
+		log("\n");
+		log("\n");
+		log("    verilog_defaults -push");
+		log("    verilog_defaults -pop");
+		log("\n");
+		log("Push or pop the list of default options to a stack. Note that -push does\n");
+		log("not imply -clear.\n");
+		log("\n");
+	}
+	virtual void execute(std::vector<std::string> args, RTLIL::Design*)
+	{
+		if (args.size() == 0)
+			cmd_error(args, 1, "Missing argument.");
+
+		if (args[1] == "-add") {
+			verilog_defaults.insert(verilog_defaults.end(), args.begin()+2, args.end());
+			return;
+		}
+
+		if (args.size() != 2)
+			cmd_error(args, 2, "Extra argument.");
+
+		if (args[1] == "-clear") {
+			verilog_defaults.clear();
+			return;
+		}
+
+		if (args[1] == "-push") {
+			verilog_defaults_stack.push_back(verilog_defaults);
+			return;
+		}
+
+		if (args[1] == "-pop") {
+			if (verilog_defaults_stack.empty()) {
+				verilog_defaults.clear();
+			} else {
+				verilog_defaults.swap(verilog_defaults_stack.back());
+				verilog_defaults_stack.pop_back();
+			}
+			return;
+		}
+	}
+} VerilogDefaults;
+
diff --git a/kernel/log.h b/kernel/log.h
index 5ee6b5651..c4c03352a 100644
--- a/kernel/log.h
+++ b/kernel/log.h
@@ -95,11 +95,16 @@ struct PerformanceTimer
 
 // simple API for quickly dumping values when debugging
 
+static inline void log_dump_val_worker(short v) { log("%d", v); }
+static inline void log_dump_val_worker(unsigned short v) { log("%u", v); }
 static inline void log_dump_val_worker(int v) { log("%d", v); }
-static inline void log_dump_val_worker(size_t v) { log("%zd", v); }
+static inline void log_dump_val_worker(unsigned int v) { log("%u", v); }
 static inline void log_dump_val_worker(long int v) { log("%ld", v); }
+static inline void log_dump_val_worker(unsigned long int v) { log("%lu", v); }
 static inline void log_dump_val_worker(long long int v) { log("%lld", v); }
+static inline void log_dump_val_worker(unsigned long long int v) { log("%lld", v); }
 static inline void log_dump_val_worker(char c) { log(c >= 32 && c < 127 ? "'%c'" : "'\\x%02x'", c); }
+static inline void log_dump_val_worker(unsigned char c) { log(c >= 32 && c < 127 ? "'%c'" : "'\\x%02x'", c); }
 static inline void log_dump_val_worker(bool v) { log("%s", v ? "true" : "false"); }
 static inline void log_dump_val_worker(double v) { log("%f", v); }
 static inline void log_dump_val_worker(const char *v) { log("%s", v); }
diff --git a/kernel/rtlil.h b/kernel/rtlil.h
index 504fdbbdc..e0b3a693d 100644
--- a/kernel/rtlil.h
+++ b/kernel/rtlil.h
@@ -227,6 +227,9 @@ struct RTLIL::Selection {
 		if (!full_selection && selected_modules.count(module->name) == 0)
 			selected_members[module->name].insert(member->name);
 	}
+	bool empty() const {
+		return !full_selection && selected_modules.empty() && selected_members.empty();
+	}
 };
 
 struct RTLIL::Design {
diff --git a/passes/cmds/Makefile.inc b/passes/cmds/Makefile.inc
index 9e96ff361..ea70f40c0 100644
--- a/passes/cmds/Makefile.inc
+++ b/passes/cmds/Makefile.inc
@@ -6,6 +6,7 @@ OBJS += passes/cmds/show.o
 OBJS += passes/cmds/rename.o
 OBJS += passes/cmds/connect.o
 OBJS += passes/cmds/scatter.o
+OBJS += passes/cmds/setundef.o
 OBJS += passes/cmds/splitnets.o
 OBJS += passes/cmds/stat.o
 
diff --git a/passes/cmds/select.cc b/passes/cmds/select.cc
index ec560772e..550545384 100644
--- a/passes/cmds/select.cc
+++ b/passes/cmds/select.cc
@@ -656,6 +656,7 @@ struct SelectPass : public Pass {
 		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
 		log("\n");
 		log("    select [ -add | -del | -set <name> ] <selection>\n");
+		log("    select [ -assert-none | -assert-any ] <selection>\n");
 		log("    select [ -list | -write <filename> | -count | -clear ]\n");
 		log("    select -module <modname>\n");
 		log("\n");
@@ -676,6 +677,14 @@ struct SelectPass : public Pass {
 		log("        do not modify the current selection. instead save the new selection\n");
 		log("        under the given name (see @<name> below).\n");
 		log("\n");
+		log("    -assert-none\n");
+		log("        asserts that the given selection is empty. i.e. produce an error if\n");
+		log("        any object matching the selection is found.\n");
+		log("\n");
+		log("    -assert-any\n");
+		log("        asserts that the given selection is non-empty. i.e. produce an error\n");
+		log("        if no object matching the selection is found.\n");
+		log("\n");
 		log("    -list\n");
 		log("        list all objects in the current selection\n");
 		log("\n");
@@ -802,6 +811,8 @@ struct SelectPass : public Pass {
 		bool list_mode = false;
 		bool count_mode = false;
 		bool got_module = false;
+		bool assert_none = false;
+		bool assert_any = false;
 		std::string write_file;
 		std::string set_name;
 
@@ -819,6 +830,14 @@ struct SelectPass : public Pass {
 				del_mode = true;
 				continue;
 			}
+			if (arg == "-assert-none") {
+				assert_none = true;
+				continue;
+			}
+			if (arg == "-assert-any") {
+				assert_any = true;
+				continue;
+			}
 			if (arg == "-clear") {
 				clear_mode = true;
 				continue;
@@ -853,16 +872,16 @@ struct SelectPass : public Pass {
 		}
 
 		if (clear_mode && args.size() != 2)
-			log_cmd_error("Option -clear can not be combined with other options.\n");
+			log_cmd_error("Option -clear can not be combined with any other options.\n");
 
-		if (add_mode && del_mode)
-			log_cmd_error("Options -add and -del can not be combined.\n");
+		if (add_mode + del_mode + assert_none + assert_any > 1)
+			log_cmd_error("Options -add, -del, -assert-none or -assert-any can not be combined.\n");
 
-		if ((list_mode || !write_file.empty() || count_mode) && (add_mode || del_mode))
-			log_cmd_error("Options -list, -write and -count can not be combined with -add or -del.\n");
+		if ((list_mode || !write_file.empty() || count_mode) && (add_mode || del_mode || assert_none || assert_any))
+			log_cmd_error("Options -list, -write and -count can not be combined with -add, -del, -assert-none or -assert-any.\n");
 
-		if (!set_name.empty() && (list_mode || !write_file.empty() || count_mode || add_mode || del_mode))
-			log_cmd_error("Option -set can not be combined with -list, -write, -count, -add or -del.\n");
+		if (!set_name.empty() && (list_mode || !write_file.empty() || count_mode || add_mode || del_mode || assert_none || assert_any))
+			log_cmd_error("Option -set can not be combined with -list, -write, -count, -add, -del, -assert-none or -assert-any.\n");
 
 		if (work_stack.size() == 0 && got_module) {
 			RTLIL::Selection sel;
@@ -943,6 +962,24 @@ struct SelectPass : public Pass {
 			return;
 		}
 
+		if (assert_none)
+		{
+			if (work_stack.size() == 0)
+				log_cmd_error("No selection to check.\n");
+			if (!work_stack.back().empty())
+				log_error("Assertation failed: selection is not empty.\n");
+			return;
+		}
+
+		if (assert_any)
+		{
+			if (work_stack.size() == 0)
+				log_cmd_error("No selection to check.\n");
+			if (work_stack.back().empty())
+				log_error("Assertation failed: selection is empty.\n");
+			return;
+		}
+
 		if (!set_name.empty())
 		{
 			if (work_stack.size() == 0)
diff --git a/passes/cmds/setundef.cc b/passes/cmds/setundef.cc
new file mode 100644
index 000000000..9d59834c2
--- /dev/null
+++ b/passes/cmds/setundef.cc
@@ -0,0 +1,157 @@
+/*
+ *  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/register.h"
+#include "kernel/celltypes.h"
+#include "kernel/sigtools.h"
+#include "kernel/rtlil.h"
+#include "kernel/log.h"
+
+static int next_bit_mode;
+static uint32_t next_bit_state;
+
+static RTLIL::State next_bit()
+{
+	if (next_bit_mode == 0)
+		return RTLIL::State::S0;
+
+	if (next_bit_mode == 1)
+		return RTLIL::State::S1;
+
+	// xorshift32
+	next_bit_state ^= next_bit_state << 13;
+	next_bit_state ^= next_bit_state >> 17;
+	next_bit_state ^= next_bit_state << 5;
+	log_assert(next_bit_state != 0);
+
+	return ((next_bit_state >> (next_bit_state & 15)) & 16) ? RTLIL::State::S0 : RTLIL::State::S1;
+}
+
+struct SetundefWorker
+{
+	void operator()(RTLIL::SigSpec &sig)
+	{
+		sig.expand();
+		for (auto &c : sig.chunks)
+			if (c.wire == NULL && c.data.bits.at(0) > RTLIL::State::S1)
+				c.data.bits.at(0) = next_bit();
+		sig.optimize();
+	}
+};
+
+struct SetundefPass : public Pass {
+	SetundefPass() : Pass("setundef", "replace undef values with defined constants") { }
+	virtual void help()
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    setundef [options] [selection]\n");
+		log("\n");
+		log("This command replaced undef (x) constants with defined (0/1) constants.\n");
+		log("\n");
+		log("    -undriven\n");
+		log("        also set undriven nets to constant values\n");
+		log("\n");
+		log("    -zero\n");
+		log("        replace with bits cleared (0)\n");
+		log("\n");
+		log("    -one\n");
+		log("        replace with bits set (1)\n");
+		log("\n");
+		log("    -random <seed>\n");
+		log("        replace with random bits using the specified integer als seed\n");
+		log("        value for the random number generator.\n");
+		log("\n");
+	}
+	virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
+	{
+		bool got_value = false;
+		bool undriven_mode = false;
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++)
+		{
+			if (args[argidx] == "-undriven") {
+				undriven_mode = true;
+				continue;
+			}
+			if (args[argidx] == "-zero") {
+				got_value = true;
+				next_bit_mode = 0;
+				continue;
+			}
+			if (args[argidx] == "-one") {
+				got_value = true;
+				next_bit_mode = 1;
+				continue;
+			}
+			if (args[argidx] == "-random" && !got_value && argidx+1 < args.size()) {
+				got_value = true;
+				next_bit_mode = 2;
+				next_bit_state = atoi(args[++argidx].c_str()) + 1;
+				for (int i = 0; i < 10; i++)
+					next_bit();
+				continue;
+			}
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		if (!got_value)
+			log_cmd_error("One of the options -zero, -one, or -random <seed> must be specified.\n");
+
+		for (auto &mod_it : design->modules)
+		{
+			RTLIL::Module *module = mod_it.second;
+			if (!design->selected(module))
+				continue;
+
+			if (undriven_mode)
+			{
+				if (!module->processes.empty())
+					log_error("The 'setundef' command can't operate in -undriven mode on modules with processes. Run 'proc' first.\n");
+
+				SigMap sigmap(module);
+				SigPool undriven_signals;
+
+				for (auto &it : module->wires)
+					if (!it.second->port_input)
+						undriven_signals.add(sigmap(it.second));
+
+				CellTypes ct(design);
+				for (auto &it : module->cells)
+				for (auto &conn : it.second->connections)
+					if (!ct.cell_known(it.second->type) || ct.cell_output(it.second->type, conn.first))
+						undriven_signals.del(sigmap(conn.second));
+
+				RTLIL::SigSpec sig = undriven_signals.export_all();
+				for (auto &c : sig.chunks) {
+					RTLIL::SigSpec bits;
+					for (int i = 0; i < c.width; i++)
+						bits.append(next_bit());
+					bits.optimize();
+					module->connections.push_back(RTLIL::SigSig(c, bits));
+				}
+			}
+
+			module->rewrite_sigspecs(SetundefWorker());
+		}
+	}
+} SetundefPass;
+ 
diff --git a/passes/memory/Makefile.inc b/passes/memory/Makefile.inc
index cffdefe85..21f17db5b 100644
--- a/passes/memory/Makefile.inc
+++ b/passes/memory/Makefile.inc
@@ -2,5 +2,6 @@
 OBJS += passes/memory/memory.o
 OBJS += passes/memory/memory_dff.o
 OBJS += passes/memory/memory_collect.o
+OBJS += passes/memory/memory_unpack.o
 OBJS += passes/memory/memory_map.o
 
diff --git a/passes/memory/memory_unpack.cc b/passes/memory/memory_unpack.cc
new file mode 100644
index 000000000..060d8e671
--- /dev/null
+++ b/passes/memory/memory_unpack.cc
@@ -0,0 +1,116 @@
+/*
+ *  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/register.h"
+#include "kernel/log.h"
+#include <sstream>
+#include <algorithm>
+#include <stdlib.h>
+#include <assert.h>
+
+static void handle_memory(RTLIL::Module *module, RTLIL::Cell *memory)
+{
+	log("Creating $memrd and $memwr for memory `%s' in module `%s':\n",
+			memory->name.c_str(), module->name.c_str());
+
+	RTLIL::IdString mem_name = RTLIL::escape_id(memory->parameters.at("\\MEMID").decode_string());
+
+	while (module->memories.count(mem_name) != 0)
+		mem_name += stringf("_%d", RTLIL::autoidx++);
+
+	RTLIL::Memory *mem = new RTLIL::Memory;
+	mem->name = mem_name;
+	mem->width = memory->parameters.at("\\WIDTH").as_int();
+	mem->start_offset = memory->parameters.at("\\OFFSET").as_int();
+	mem->size = memory->parameters.at("\\SIZE").as_int();
+	module->memories[mem_name] = mem;
+
+	int abits = memory->parameters.at("\\ABITS").as_int();
+	int num_rd_ports = memory->parameters.at("\\RD_PORTS").as_int();
+	int num_wr_ports = memory->parameters.at("\\WR_PORTS").as_int();
+
+	for (int i = 0; i < num_rd_ports; i++)
+	{
+		RTLIL::Cell *cell = new RTLIL::Cell;
+		cell->name = NEW_ID;
+		cell->type = "$memrd";
+		cell->parameters["\\MEMID"] = mem_name;
+		cell->parameters["\\ABITS"] = memory->parameters.at("\\ABITS");
+		cell->parameters["\\WIDTH"] = memory->parameters.at("\\WIDTH");
+		cell->parameters["\\CLK_ENABLE"] = RTLIL::SigSpec(memory->parameters.at("\\RD_CLK_ENABLE")).extract(i, 1).as_const();
+		cell->parameters["\\CLK_POLARITY"] = RTLIL::SigSpec(memory->parameters.at("\\RD_CLK_POLARITY")).extract(i, 1).as_const();
+		cell->connections["\\CLK"] = memory->connections.at("\\RD_CLK").extract(i, 1);
+		cell->connections["\\ADDR"] = memory->connections.at("\\RD_ADDR").extract(i*abits, abits);
+		cell->connections["\\DATA"] = memory->connections.at("\\RD_DATA").extract(i*mem->width, mem->width);
+		module->add(cell);
+	}
+
+	for (int i = 0; i < num_wr_ports; i++)
+	{
+		RTLIL::Cell *cell = new RTLIL::Cell;
+		cell->name = NEW_ID;
+		cell->type = "$memwr";
+		cell->parameters["\\MEMID"] = mem_name;
+		cell->parameters["\\ABITS"] = memory->parameters.at("\\ABITS");
+		cell->parameters["\\WIDTH"] = memory->parameters.at("\\WIDTH");
+		cell->parameters["\\CLK_ENABLE"] = RTLIL::SigSpec(memory->parameters.at("\\WR_CLK_ENABLE")).extract(i, 1).as_const();
+		cell->parameters["\\CLK_POLARITY"] = RTLIL::SigSpec(memory->parameters.at("\\WR_CLK_POLARITY")).extract(i, 1).as_const();
+		cell->parameters["\\PRIORITY"] = i;
+		cell->connections["\\CLK"] = memory->connections.at("\\WR_CLK").extract(i, 1);
+		cell->connections["\\EN"] = memory->connections.at("\\WR_EN").extract(i, 1);
+		cell->connections["\\ADDR"] = memory->connections.at("\\WR_ADDR").extract(i*abits, abits);
+		cell->connections["\\DATA"] = memory->connections.at("\\WR_DATA").extract(i*mem->width, mem->width);
+		module->add(cell);
+	}
+
+	module->cells.erase(memory->name);
+	delete memory;
+}
+
+static void handle_module(RTLIL::Design *design, RTLIL::Module *module)
+{
+	std::vector<RTLIL::IdString> memcells;
+	for (auto &cell_it : module->cells)
+		if (cell_it.second->type == "$mem" && design->selected(module, cell_it.second))
+			memcells.push_back(cell_it.first);
+	for (auto &it : memcells)
+		handle_memory(module, module->cells.at(it));
+}
+
+struct MemoryUnpackPass : public Pass {
+	MemoryUnpackPass() : Pass("memory_unpack", "unpack multi-port memory cells") { }
+	virtual void help()
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    memory_unpack [selection]\n");
+		log("\n");
+		log("This pass converts the multi-port $mem memory cells into individual $memrd and\n");
+		log("$memwr cells. It is the counterpart to the memory_collect pass.\n");
+		log("\n");
+	}
+	virtual void execute(std::vector<std::string> args, RTLIL::Design *design) {
+		log_header("Executing MEMORY_UNPACK pass (generating $memrd/$memwr cells form $mem cells).\n");
+		extra_args(args, 1, design);
+		for (auto &mod_it : design->modules)
+			if (design->selected(mod_it.second))
+				handle_module(design, mod_it.second);
+	}
+} MemoryUnpackPass;
+ 
diff --git a/passes/opt/opt_rmdff.cc b/passes/opt/opt_rmdff.cc
index a84bf4376..9ce98004e 100644
--- a/passes/opt/opt_rmdff.cc
+++ b/passes/opt/opt_rmdff.cc
@@ -92,6 +92,12 @@ static bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
 		}
 	}
 
+	if (sig_d.is_fully_undef() && sig_d.width == int(val_rv.bits.size())) {
+		RTLIL::SigSig conn(sig_q, val_rv);
+		mod->connections.push_back(conn);
+		goto delete_dff;
+	}
+
 	if (sig_d.is_fully_const() && sig_r.width == 0) {
 		RTLIL::SigSig conn(sig_q, sig_d);
 		mod->connections.push_back(conn);
diff --git a/techlibs/common/Makefile.inc b/techlibs/common/Makefile.inc
index e2e1ba25a..6d94d5c9b 100644
--- a/techlibs/common/Makefile.inc
+++ b/techlibs/common/Makefile.inc
@@ -5,7 +5,7 @@ techlibs/common/blackbox.v: techlibs/common/blackbox.sed techlibs/common/simlib.
 	cat techlibs/common/simlib.v techlibs/common/simcells.v | sed -rf techlibs/common/blackbox.sed > techlibs/common/blackbox.v.new
 	mv techlibs/common/blackbox.v.new techlibs/common/blackbox.v
 
-EXTRA_TARGETS += share/simlib.v share/simcells.v share/blackbox.v
+EXTRA_TARGETS += share/simlib.v share/simcells.v share/blackbox.v share/pmux2mux.v
 
 share/simlib.v: techlibs/common/simlib.v
 	mkdir -p share
@@ -19,3 +19,7 @@ share/blackbox.v: techlibs/common/blackbox.v
 	mkdir -p share
 	cp techlibs/common/blackbox.v share/blackbox.v
 
+share/pmux2mux.v: techlibs/common/pmux2mux.v
+	mkdir -p share
+	cp techlibs/common/pmux2mux.v share/pmux2mux.v
+
diff --git a/techlibs/common/pmux2mux.v b/techlibs/common/pmux2mux.v
new file mode 100644
index 000000000..9c97245a1
--- /dev/null
+++ b/techlibs/common/pmux2mux.v
@@ -0,0 +1,21 @@
+module \$pmux (A, B, S, Y);
+
+wire [1023:0] _TECHMAP_DO_ = "proc; clean";
+
+parameter WIDTH = 1;
+parameter S_WIDTH = 1;
+
+input [WIDTH-1:0] A;
+input [WIDTH*S_WIDTH-1:0] B;
+input [S_WIDTH-1:0] S;
+output reg [WIDTH-1:0] Y;
+
+integer i;
+
+always @* begin
+	Y <= A;
+	for (i = 0; i < S_WIDTH; i=i+1)
+		if (S[i]) Y <= B[WIDTH*i +: WIDTH];
+end
+
+endmodule
diff --git a/techlibs/common/simlib.v b/techlibs/common/simlib.v
index 034244ca6..f3d652f0e 100644
--- a/techlibs/common/simlib.v
+++ b/techlibs/common/simlib.v
@@ -55,6 +55,28 @@ endmodule
 
 // --------------------------------------------------------
 
+module \$bu0 (A, Y);
+
+parameter A_SIGNED = 0;
+parameter A_WIDTH = 0;
+parameter Y_WIDTH = 0;
+
+`INPUT_A
+output [Y_WIDTH-1:0] Y;
+
+generate
+	if (!A_SIGNED && 0 < A_WIDTH && A_WIDTH < Y_WIDTH) begin:A
+		assign Y[A_WIDTH-1:0] = A_BUF.val;
+		assign Y[Y_WIDTH-1:A_WIDTH] = 0;
+	end else begin:B
+		assign Y = +A_BUF.val;
+	end
+endgenerate
+
+endmodule
+
+// --------------------------------------------------------
+
 module \$pos (A, Y);
 
 parameter A_SIGNED = 0;
diff --git a/techlibs/common/stdcells.v b/techlibs/common/stdcells.v
index 4e764078e..e33e651ca 100644
--- a/techlibs/common/stdcells.v
+++ b/techlibs/common/stdcells.v
@@ -456,7 +456,7 @@ wire [WIDTH-1:0] A_buf, B_buf, Y_buf;
 	.Cin(1'b1),
 	.Y(Y_buf),
 	.Cout(carry),
-	.Csign(carry_sign),
+	.Csign(carry_sign)
 );
 
 // ALU flags
@@ -505,7 +505,7 @@ wire [WIDTH-1:0] A_buf, B_buf, Y_buf;
 	.Cin(1'b1),
 	.Y(Y_buf),
 	.Cout(carry),
-	.Csign(carry_sign),
+	.Csign(carry_sign)
 );
 
 // ALU flags
@@ -849,7 +849,7 @@ assign B_buf_u = B_SIGNED && B_buf[WIDTH-1] ? -B_buf : B_buf;
 	.A(A_buf_u),
 	.B(B_buf_u),
 	.Y(Y_u),
-	.R(R_u),
+	.R(R_u)
 );
 
 assign Y = A_SIGNED && B_SIGNED && (A_buf[WIDTH-1] != B_buf[WIDTH-1]) ? -Y_u : Y_u;