Merge remote-tracking branch 'origin/eddie/opt_rmdff' into xc7mux

backends/firrtl/firrtl.cc

@@ -449,8 +449,10 @@ struct FirrtlWorker
 				string primop;
 				bool always_uint = false;
 				if (cell->type == "$not") primop = "not";
-				else if (cell->type == "$neg") primop = "neg";
+				else if (cell->type == "$neg") {
-				else if (cell->type == "$logic_not") {
+					primop = "neg";
+					is_signed = true;	// Result of "neg" is signed (an SInt).
+				} else if (cell->type == "$logic_not") {
                                         primop = "eq";
                                         a_expr = stringf("%s, UInt(0)", a_expr.c_str());
                                 }
@@ -562,6 +564,7 @@ struct FirrtlWorker
 					auto b_sig = cell->getPort("\\B");
 					if (b_sig.is_fully_const()) {
 						primop = "shl";
+						b_expr = std::to_string(b_sig.as_int());
 					} else {
 						primop = "dshl";
 						// Convert from FIRRTL left shift semantics.
@@ -575,6 +578,7 @@ struct FirrtlWorker
 					auto b_sig = cell->getPort("\\B");
 					if (b_sig.is_fully_const()) {
 						primop = "shr";
+						b_expr = std::to_string(b_sig.as_int());
 					} else {
 						primop = "dshr";
 					}

frontends/aiger/aigerparse.cc

@@ -57,11 +57,15 @@ void AigerReader::parse_aiger()
 
     // Optional values
     B = C = J = F = 0;
-    for (auto &i : std::array<std::reference_wrapper<unsigned>,4>{B, C, J, F}) {
+    if (f.peek() != ' ') goto end_of_header;
-        if (f.peek() != ' ') break;
+    if (!(f >> B)) log_error("Invalid AIGER header\n");
-        if (!(f >> i))
+    if (f.peek() != ' ') goto end_of_header;
-            log_error("Invalid AIGER header\n");
+    if (!(f >> C)) log_error("Invalid AIGER header\n");
-    }
+    if (f.peek() != ' ') goto end_of_header;
+    if (!(f >> J)) log_error("Invalid AIGER header\n");
+    if (f.peek() != ' ') goto end_of_header;
+    if (!(f >> F)) log_error("Invalid AIGER header\n");
+end_of_header:
 
     std::string line;
     std::getline(f, line); // Ignore up to start of next line, as standard

libs/subcircuit/subcircuit.cc

@@ -320,12 +320,10 @@ class SubCircuit::SolverWorker
 
 	static int numberOfPermutations(const std::vector<std::string> &list)
 	{
-		int numPermutations = 1;
+		constexpr size_t mappedPermutationsSize = 10;
-		for (int i = 0; i < int(list.size()); i++) {
+		constexpr int mappedPermutations[mappedPermutationsSize] = {1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880};
-			assert(numPermutations < maxPermutationsLimit);
+		assert(list.size() < mappedPermutationsSize);
-			numPermutations *= i+1;
+		return mappedPermutations[list.size()];
-		}
-		return numPermutations;
 	}
 
 	static void permutateVectorToMap(std::map<std::string, std::string> &map, const std::vector<std::string> &list, int idx)

passes/opt/opt_rmdff.cc

@@ -260,8 +260,8 @@ delete_dlatch:
 
 bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
 {
-	RTLIL::SigSpec sig_d, sig_q, sig_c, sig_r;
+	RTLIL::SigSpec sig_d, sig_q, sig_c, sig_r, sig_e;
-	RTLIL::Const val_cp, val_rp, val_rv;
+	RTLIL::Const val_cp, val_rp, val_rv, val_ep;
 
 	if (dff->type == "$_FF_") {
 		sig_d = dff->getPort("\\D");
@@ -285,6 +285,16 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
 		val_rp = RTLIL::Const(dff->type[7] == 'P', 1);
 		val_rv = RTLIL::Const(dff->type[8] == '1', 1);
 	}
+	else if (dff->type.substr(0,7) == "$_DFFE_" && dff->type.substr(9) == "_" &&
+			(dff->type[7] == 'N' || dff->type[7] == 'P') &&
+			(dff->type[8] == 'N' || dff->type[8] == 'P')) {
+		sig_d = dff->getPort("\\D");
+		sig_q = dff->getPort("\\Q");
+		sig_c = dff->getPort("\\C");
+		sig_e = dff->getPort("\\E");
+		val_cp = RTLIL::Const(dff->type[6] == 'P', 1);
+		val_ep = RTLIL::Const(dff->type[7] == 'P', 1);
+	}
 	else if (dff->type == "$ff") {
 		sig_d = dff->getPort("\\D");
 		sig_q = dff->getPort("\\Q");
@@ -295,6 +305,14 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
 		sig_c = dff->getPort("\\CLK");
 		val_cp = RTLIL::Const(dff->parameters["\\CLK_POLARITY"].as_bool(), 1);
 	}
+	else if (dff->type == "$dffe") {
+		sig_e = dff->getPort("\\EN");
+		sig_d = dff->getPort("\\D");
+		sig_q = dff->getPort("\\Q");
+		sig_c = dff->getPort("\\CLK");
+		val_cp = RTLIL::Const(dff->parameters["\\CLK_POLARITY"].as_bool(), 1);
+		val_ep = RTLIL::Const(dff->parameters["\\EN_POLARITY"].as_bool(), 1);
+	}
 	else if (dff->type == "$adff") {
 		sig_d = dff->getPort("\\D");
 		sig_q = dff->getPort("\\Q");
@@ -320,6 +338,16 @@ bool handle_dff(RTLIL::Module *mod, RTLIL::Cell *dff)
 		val_init.bits.push_back(bit.wire == NULL ? bit.data : RTLIL::State::Sx);
 	}
 
+	if (sig_e.size()) {
+		if (!sig_e.is_fully_const())
+			return false;
+		if (sig_e != val_ep) {
+			if (has_init)
+				mod->connect(sig_q, val_init);
+			goto delete_dff;
+		}
+	}
+
 	if (dff->type.in("$ff", "$dff") && mux_drivers.has(sig_d)) {
 		std::set<RTLIL::Cell*> muxes;
 		mux_drivers.find(sig_d, muxes);
@@ -489,7 +517,8 @@ struct OptRmdffPass : public Pass {
 				if (cell->type.in("$_FF_", "$_DFF_N_", "$_DFF_P_",
 						"$_DFF_NN0_", "$_DFF_NN1_", "$_DFF_NP0_", "$_DFF_NP1_",
 						"$_DFF_PN0_", "$_DFF_PN1_", "$_DFF_PP0_", "$_DFF_PP1_",
-						"$ff", "$dff", "$adff"))
+						"$_DFFE_NN_", "$_DFFE_NP_", "$_DFFE_PN_", "$_DFFE_PP_",
+						"$ff", "$dff", "$dffe", "$adff"))
 					dff_list.push_back(cell->name);
 
 				if (cell->type.in("$dlatch", "$_DLATCH_P_", "$_DLATCH_N_"))

passes/opt/wreduce.cc

@@ -29,6 +29,7 @@ PRIVATE_NAMESPACE_BEGIN
 struct WreduceConfig
 {
 	pool<IdString> supported_cell_types;
+	bool keepdc = false;
 
 	WreduceConfig()
 	{
@@ -82,7 +83,7 @@ struct WreduceWorker
 
 			SigBit ref = sig_a[i];
 			for (int k = 0; k < GetSize(sig_s); k++) {
-				if (ref != Sx && sig_b[k*GetSize(sig_a) + i] != Sx && ref != sig_b[k*GetSize(sig_a) + i])
+				if ((config->keepdc || (ref != Sx && sig_b[k*GetSize(sig_a) + i] != Sx)) && ref != sig_b[k*GetSize(sig_a) + i])
 					goto no_match_ab;
 				if (sig_b[k*GetSize(sig_a) + i] != Sx)
 					ref = sig_b[k*GetSize(sig_a) + i];
@@ -497,6 +498,9 @@ struct WreducePass : public Pass {
 		log("        Do not change the width of memory address ports. Use this options in\n");
 		log("        flows that use the 'memory_memx' pass.\n");
 		log("\n");
+		log("    -keepdc\n");
+		log("        Do not optimize explicit don't-care values.\n");
+		log("\n");
 	}
 	void execute(std::vector<std::string> args, Design *design) YS_OVERRIDE
 	{
@@ -511,6 +515,10 @@ struct WreducePass : public Pass {
 				opt_memx = true;
 				continue;
 			}
+			if (args[argidx] == "-keepdc") {
+				config.keepdc = true;
+				continue;
+			}
 			break;
 		}
 		extra_args(args, argidx, design);

techlibs/common/prep.cc

@@ -195,9 +195,11 @@ struct PrepPass : public ScriptPass
 			run(nokeepdc ? "opt" : "opt -keepdc");
 			if (!ifxmode) {
 				if (help_mode)
-					run("wreduce [-memx]");
+					run("wreduce -keepdc [-memx]");
-				else
+				else if (nokeepdc)
 					run(memxmode ? "wreduce -memx" : "wreduce");
+				else
+					run(memxmode ? "wreduce -keepdc -memx" : "wreduce -keepdc");
 			}
 			if (!nomemmode) {
 				run(string("memory_dff") + (help_mode ? " [-nordff]" : nordff ? " -nordff" : ""));

tests/various/opt_rmdff.v

@@ -0,0 +1,30 @@
+module opt_rmdff_test (input C, input D, input E, output reg [16:0] Q);
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) remove0 (.CLK(C), .D(D), .EN(1'b0), .Q(Q[0]));
+initial Q[1] = 1'b1;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) remove1 (.CLK(C), .D(D), .EN(1'b0), .Q(Q[1]));
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) remove2 (.CLK(C), .D(D), .EN(1'bx), .Q(Q[2]));
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(1)) keep2 (.CLK(C), .D(D), .EN(1'b1), .Q(Q[2]));
+initial Q[3] = 1'b0;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(0), .EN_POLARITY(1)) keep3 (.CLK(C), .D(D), .EN(1'b1), .Q(Q[3]));
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(0)) remove4 (.CLK(C), .D(D), .EN(1'b1), .Q(Q[4]));
+\$dffe #(.WIDTH(1), .CLK_POLARITY(1), .EN_POLARITY(0)) remove5 (.CLK(C), .D(D), .EN(1'bx), .Q(Q[5]));
+initial Q[6] = 1'b0;
+\$dffe #(.WIDTH(1), .CLK_POLARITY(0), .EN_POLARITY(0)) keep6 (.CLK(C), .D(D), .EN(E), .Q(Q[6]));
+
+\$_DFFE_PP_ remove7 (.C(C), .D(D), .E(1'b0), .Q(Q[7]));
+initial Q[8] = 1'b1;
+\$_DFFE_PP_ remove8 (.C(C), .D(D), .E(1'b0), .Q(Q[8]));
+\$_DFFE_PP_ remove9 (.C(C), .D(D), .E(1'bx), .Q(Q[9]));
+\$_DFFE_PP_ keep10 (.C(C), .D(D), .E(1'b1), .Q(Q[10]));
+initial Q[11] = 1'b0;
+\$_DFFE_PP_ keep11 (.C(C), .D(D), .E(1'b1), .Q(Q[11]));
+
+\$_DFFE_NN_ remove12 (.C(C), .D(D), .E(1'b1), .Q(Q[12]));
+initial Q[13] = 1'b1;
+\$_DFFE_NN_ remove13 (.C(C), .D(D), .E(1'b1), .Q(Q[13]));
+\$_DFFE_NN_ remove14 (.C(C), .D(D), .E(1'bx), .Q(Q[14]));
+\$_DFFE_NN_ keep15 (.C(C), .D(D), .E(1'b0), .Q(Q[15]));
+initial Q[16] = 1'b0;
+\$_DFFE_NN_ keep16 (.C(C), .D(D), .E(1'b0), .Q(Q[16]));
+
+endmodule

tests/various/opt_rmdff.ys

@@ -0,0 +1,25 @@
+read_verilog -icells opt_rmdff.v
+prep
+design -stash gold
+read_verilog -icells opt_rmdff.v
+opt_rmdff
+
+select -assert-count 0 c:remove*
+select -assert-min 7 c:keep*
+
+prep
+design -stash gate
+
+design -import gold -as gold
+design -import gate -as gate
+
+equiv_make gold gate equiv
+hierarchy -top equiv
+equiv_simple -undef
+equiv_status -assert
+
+design -load gold
+stat
+
+design -load gate
+stat