Improvements in "shregmap"

1 files changed, 140 insertions, 30 deletions

diff --git a/passes/techmap/shregmap.cc b/passes/techmap/shregmap.cc
index ad5c50cd6..d9c725573 100644
--- a/passes/techmap/shregmap.cc
+++ b/passes/techmap/shregmap.cc
@@ -25,13 +25,12 @@ PRIVATE_NAMESPACE_BEGIN
 
 struct ShregmapOptions
 {
-	std::string clkpol;
 	int minlen, maxlen;
 	int keep_before, keep_after;
+	dict<IdString, pair<IdString, IdString>> ffcells;
 
 	ShregmapOptions()
 	{
-		clkpol = "any";
 		minlen = 2;
 		maxlen = 0;
 		keep_before = 0;
@@ -46,41 +45,59 @@ struct ShregmapWorker
 
 	const ShregmapOptions &opts;
 	int dff_count, shreg_count;
+	pool<Cell*> remove_cells;
 
-	// next is set to NULL for sigbits that drive non-DFFs
+	dict<SigBit, bool> sigbit_init;
 	dict<SigBit, Cell*> sigbit_chain_next;
 	dict<SigBit, Cell*> sigbit_chain_prev;
+	pool<SigBit> sigbit_with_non_chain_users;
 	pool<Cell*> chain_start_cells;
 
 	void make_sigbit_chain_next_prev()
 	{
-		for (auto wire : module->wires()) {
-			if (!wire->port_output)
-				continue;
-			for (auto bit : sigmap(wire))
-				sigbit_chain_next[bit] = nullptr;
+		for (auto wire : module->wires())
+		{
+			if (wire->port_output) {
+				for (auto bit : sigmap(wire))
+					sigbit_with_non_chain_users.insert(bit);
+			}
+
+			if (wire->attributes.count("\\init")) {
+				SigSpec initsig = sigmap(wire);
+				Const initval = wire->attributes.at("\\init");
+				for (int i = 0; i < GetSize(initsig) && i < GetSize(initval); i++)
+					if (initval[i] == State::S0)
+						sigbit_init[initsig[i]] = false;
+					else if (initval[i] == State::S1)
+						sigbit_init[initsig[i]] = true;
+			}
 		}
 
 		for (auto cell : module->cells())
 		{
-			if ((opts.clkpol != "pos" && cell->type == "$_DFF_N_") ||
-					(opts.clkpol != "neg" && cell->type == "$_DFF_P_"))
+			if (opts.ffcells.count(cell->type))
 			{
-				SigBit d_bit = sigmap(cell->getPort("\\D").as_bit());
-				if (sigbit_chain_next.count(d_bit))
-					sigbit_chain_next[d_bit] = nullptr;
-				else
-					sigbit_chain_next[d_bit] = cell;
-
-				SigBit q_bit = sigmap(cell->getPort("\\Q").as_bit());
-				sigbit_chain_prev[q_bit] = cell;
-				continue;
+				IdString d_port = opts.ffcells.at(cell->type).first;
+				IdString q_port = opts.ffcells.at(cell->type).second;
+
+				SigBit d_bit = sigmap(cell->getPort(d_port).as_bit());
+				SigBit q_bit = sigmap(cell->getPort(q_port).as_bit());
+
+				if (sigbit_init.count(q_bit) == 0) {
+					if (sigbit_chain_next.count(d_bit)) {
+						sigbit_with_non_chain_users.insert(d_bit);
+					} else
+						sigbit_chain_next[d_bit] = cell;
+
+					sigbit_chain_prev[q_bit] = cell;
+					continue;
+				}
 			}
 
 			for (auto conn : cell->connections())
 				if (cell->input(conn.first))
 					for (auto bit : sigmap(conn.second))
-						sigbit_chain_next[bit] = nullptr;
+						sigbit_with_non_chain_users.insert(bit);
 		}
 	}
 
@@ -88,7 +105,7 @@ struct ShregmapWorker
 	{
 		for (auto it : sigbit_chain_next)
 		{
-			if (it.second == nullptr)
+			if (sigbit_with_non_chain_users.count(it.first))
 				continue;
 
 			if (sigbit_chain_prev.count(it.first) != 0)
@@ -99,7 +116,22 @@ struct ShregmapWorker
 				if (c1->type != c2->type)
 					goto start_cell;
 
-				if (sigmap(c1->getPort("\\C")) != c2->getPort("\\C"))
+				if (c1->parameters != c2->parameters)
+					goto start_cell;
+
+				IdString d_port = opts.ffcells.at(c1->type).first;
+				IdString q_port = opts.ffcells.at(c1->type).second;
+
+				auto c1_conn = c1->connections();
+				auto c2_conn = c1->connections();
+
+				c1_conn.erase(d_port);
+				c1_conn.erase(q_port);
+
+				c2_conn.erase(d_port);
+				c2_conn.erase(q_port);
+
+				if (c1_conn != c2_conn)
 					goto start_cell;
 
 				continue;
@@ -119,7 +151,8 @@ struct ShregmapWorker
 		{
 			chain.push_back(c);
 
-			SigBit q_bit = sigmap(c->getPort("\\Q").as_bit());
+			IdString q_port = opts.ffcells.at(c->type).second;
+			SigBit q_bit = sigmap(c->getPort(q_port).as_bit());
 
 			if (sigbit_chain_next.count(q_bit) == 0)
 				break;
@@ -153,16 +186,36 @@ struct ShregmapWorker
 			log("Converting %s.%s ... %s.%s to a shift register with depth %d.\n",
 				log_id(module), log_id(first_cell), log_id(module), log_id(last_cell), depth);
 
-			first_cell->type = "$__DFF_SHREG_" + first_cell->type.substr(6);
-			first_cell->setPort("\\Q", last_cell->getPort("\\Q"));
+			dff_count += depth;
+			shreg_count += 1;
+
+			string shreg_cell_type_str = "$__SHREG";
+			if (first_cell->type[1] != '_')
+				shreg_cell_type_str += "_";
+			shreg_cell_type_str += first_cell->type.substr(1);
+
+			IdString q_port = opts.ffcells.at(first_cell->type).second;
+			first_cell->type = shreg_cell_type_str;
+			first_cell->setPort(q_port, last_cell->getPort(q_port));
 			first_cell->setParam("\\DEPTH", depth);
 
 			for (int i = 1; i < depth; i++)
-				module->remove(chain[cursor+i]);
+				remove_cells.insert(chain[cursor+i]);
 			cursor += depth;
 		}
 	}
 
+	void cleanup()
+	{
+		for (auto cell : remove_cells)
+			module->remove(cell);
+
+		remove_cells.clear();
+		sigbit_chain_next.clear();
+		sigbit_chain_prev.clear();
+		chain_start_cells.clear();
+	}
+
 	ShregmapWorker(Module *module, const ShregmapOptions &opts) :
 			module(module), sigmap(module), opts(opts), dff_count(0), shreg_count(0)
 	{
@@ -174,6 +227,8 @@ struct ShregmapWorker
 			vector<Cell*> chain = create_chain(c);
 			process_chain(chain);
 		}
+
+		cleanup();
 	}
 };
 
@@ -186,7 +241,7 @@ struct ShregmapPass : public Pass {
 		log("    shregmap [options] [selection]\n");
 		log("\n");
 		log("This pass converts chains of $_DFF_[NP]_ gates to target specific shift register.\n");
-		log("primitives. The generated shift register will be of type $__DFF_SHREG_[NP]_ and\n");
+		log("primitives. The generated shift register will be of type $__SHREG_DFF_[NP]_ and\n");
 		log("will use the same interface as the original $_DFF_*_ cells. The cell parameter\n");
 		log("'DEPTH' will contain the depth of the shift register. Use a target-specific\n");
 		log("'techmap' map file to convert those cells to the actual target cells.\n");
@@ -208,10 +263,20 @@ struct ShregmapPass : public Pass {
 		log("    -clkpol pos|neg|any\n");
 		log("        limit match to only positive or negative edge clocks. (default = any)\n");
 		log("\n");
+		log("    -enpol pos|neg|none|any_or_none|any\n");
+		log("        limit match to FFs with the specified enable polarity. (default = none)\n");
+		log("\n");
+		log("    -match <cell_type>[:<d_port_name>:<q_port_name>]\n");
+		log("        match the specified cells instead of $_DFF_N_ and $_DFF_P_. If\n");
+		log("        ':<d_port_name>:<q_port_name>' is omitted then 'D' and 'Q' is used\n");
+		log("        by default. E.g. the option '-clkpol pos' is just an alias for\n");
+		log("        '-match $_DFF_P_', which is an alias for '-match $_DFF_P_:D:Q'.\n");
+		log("\n");
 	}
 	virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
 	{
 		ShregmapOptions opts;
+		string clkpol, enpol;
 
 		log_header("Executing SHREGMAP pass (map shift registers).\n");
 
@@ -219,7 +284,23 @@ struct ShregmapPass : public Pass {
 		for (argidx = 1; argidx < args.size(); argidx++)
 		{
 			if (args[argidx] == "-clkpol" && argidx+1 < args.size()) {
-				opts.clkpol = args[++argidx];
+				clkpol = args[++argidx];
+				continue;
+			}
+			if (args[argidx] == "-enpol" && argidx+1 < args.size()) {
+				enpol = args[++argidx];
+				continue;
+			}
+			if (args[argidx] == "-match" && argidx+1 < args.size()) {
+				vector<string> match_args = split_tokens(args[++argidx], ":");
+				if (GetSize(match_args) < 2)
+					match_args.push_back("D");
+				if (GetSize(match_args) < 3)
+					match_args.push_back("Q");
+				IdString id_cell_type(RTLIL::escape_id(match_args[0]));
+				IdString id_d_port_name(RTLIL::escape_id(match_args[1]));
+				IdString id_q_port_name(RTLIL::escape_id(match_args[2]));
+				opts.ffcells[id_cell_type] = make_pair(id_d_port_name, id_q_port_name);
 				continue;
 			}
 			if (args[argidx] == "-minlen" && argidx+1 < args.size()) {
@@ -242,8 +323,37 @@ struct ShregmapPass : public Pass {
 		}
 		extra_args(args, argidx, design);
 
-		if (opts.clkpol != "pos" && opts.clkpol != "neg" && opts.clkpol != "any")
-			log_cmd_error("Invalid value for -clkpol: %s\n", opts.clkpol.c_str());
+		if (opts.ffcells.empty())
+		{
+			bool clk_pos = clkpol == "" || clkpol == "pos" || clkpol == "any";
+			bool clk_neg = clkpol == "" || clkpol == "neg" || clkpol == "any";
+
+			bool en_none = enpol == "" || enpol == "none" || enpol == "any_or_none";
+			bool en_pos = enpol == "pos" || enpol == "any" || enpol == "any_or_none";
+			bool en_neg = enpol == "neg" || enpol == "any" || enpol == "any_or_none";
+
+			if (clk_pos && en_none)
+				opts.ffcells["$_DFF_P_"] = make_pair(IdString("\\D"), IdString("\\Q"));
+			if (clk_neg && en_none)
+				opts.ffcells["$_DFF_N_"] = make_pair(IdString("\\D"), IdString("\\Q"));
+
+			if (clk_pos && en_pos)
+				opts.ffcells["$_DFFE_PP_"] = make_pair(IdString("\\D"), IdString("\\Q"));
+			if (clk_pos && en_neg)
+				opts.ffcells["$_DFFE_PN_"] = make_pair(IdString("\\D"), IdString("\\Q"));
+
+			if (clk_neg && en_pos)
+				opts.ffcells["$_DFFE_NP_"] = make_pair(IdString("\\D"), IdString("\\Q"));
+			if (clk_neg && en_neg)
+				opts.ffcells["$_DFFE_NN_"] = make_pair(IdString("\\D"), IdString("\\Q"));
+		}
+		else
+		{
+			if (!clkpol.empty())
+				log_cmd_error("Options -clkpol and -match are exclusive!\n");
+			if (!enpol.empty())
+				log_cmd_error("Options -enpol and -match are exclusive!\n");
+		}
 
 		int dff_count = 0;
 		int shreg_count = 0;