Add tests, fix for !=

passes/techmap/muxpack.cc

@@ -54,6 +54,7 @@ struct MuxpackWorker
 			if (cell->type.in("$mux") && !cell->get_bool_attribute("\\keep"))
 			{
 				SigSpec a_sig = sigmap(cell->getPort("\\A"));
+				SigSpec b_sig = sigmap(cell->getPort("\\B"));
 				SigSpec y_sig = sigmap(cell->getPort("\\Y"));
    
 				if (sig_chain_next.count(a_sig))
@@ -62,6 +63,12 @@ struct MuxpackWorker
 				else
 					sig_chain_next[a_sig] = cell;
 
+				if (sig_chain_next.count(b_sig))
+					for (auto b_bit : b_sig.bits())
+						sigbit_with_non_chain_users.insert(b_bit);
+				else
+					sig_chain_next[b_sig] = cell;
+
 				sig_chain_prev[y_sig] = cell;
                 continue;
 			}
@@ -77,13 +84,22 @@ struct MuxpackWorker
 	{
 		for (auto it : sig_chain_next)
 		{
+			SigSpec next_sig;
+
             for (auto bit : it.first.bits())
                 if (sigbit_with_non_chain_users.count(bit))
                     goto start_cell;
 
-			if (sig_chain_prev.count(it.first) != 0)
+			next_sig = it.second->getPort("\\A");
+			if (sig_chain_prev.count(next_sig) == 0) {
+				next_sig = it.second->getPort("\\B");
+				if (sig_chain_prev.count(next_sig) == 0)
+					next_sig = SigSpec();
+			}
+
+			if (!next_sig.empty())
 			{
-				Cell *c1 = sig_chain_prev.at(it.first);
+				Cell *c1 = sig_chain_prev.at(next_sig);
 				Cell *c2 = it.second;
 
 				if (c1->type != c2->type)
@@ -153,9 +169,16 @@ struct MuxpackWorker
 			SigSpec s_sig = first_cell->getPort("\\S");
 
 			for (int i = 1; i < cases; i++) {
+				Cell* prev_cell = chain[cursor+i-1];
 				Cell* cursor_cell = chain[cursor+i];
+				if (sigmap(prev_cell->getPort("\\Y")) == sigmap(cursor_cell->getPort("\\A"))) {
 					b_sig.append(cursor_cell->getPort("\\B"));
 					s_sig.append(cursor_cell->getPort("\\S"));
+				}
+				else {
+					b_sig.append(cursor_cell->getPort("\\A"));
+					s_sig.append(module->LogicNot(NEW_ID, cursor_cell->getPort("\\S")));
+				}
 				remove_cells.insert(cursor_cell);
 			}
 

tests/various/muxpack.v

@@ -0,0 +1,36 @@
+module mux_if_unbal_4_1 #(parameter N=4, parameter W=1) (input [N*W-1:0] i, input [$clog2(N)-1:0] s, output reg [W-1:0] o);
+always @*
+    if (s == 0) o <= i[0*W+:W];
+    else if (s == 1) o <= i[1*W+:W];
+    else if (s == 2) o <= i[2*W+:W];
+    else if (s == 3) o <= i[3*W+:W];
+    else o <= {W{1'bx}};
+
+endmodule
+
+module mux_if_unbal_5_3 #(parameter N=5, parameter W=3) (input [N*W-1:0] i, input [$clog2(N)-1:0] s, output reg [W-1:0] o);
+always @* begin
+    o <= {W{1'bx}};
+    if (s == 0) o <= i[0*W+:W];
+    if (s == 1) o <= i[1*W+:W];
+    if (s == 2) o <= i[2*W+:W];
+    if (s == 3) o <= i[3*W+:W];
+    if (s == 4) o <= i[4*W+:W];
+end
+
+endmodule
+
+module mux_if_unbal_5_3_invert #(parameter N=5, parameter W=3) (input [N*W-1:0] i, input [$clog2(N)-1:0] s, output reg [W-1:0] o);
+always @*
+    if (s != 0) 
+	   	if (s != 1) 
+			if (s != 2)
+				if (s != 3)
+					if (s != 4) o <= i[4*W+:W];
+					else o <= i[0*W+:W];
+				else o <= i[3*W+:W];
+			else o <= i[2*W+:W];
+		else o <= i[1*W+:W];
+    else o <= {W{1'bx}};
+
+endmodule

tests/various/muxpack.ys

@@ -0,0 +1,42 @@
+read_verilog muxpack.v
+design -save read
+hierarchy -top mux_if_unbal_4_1
+prep
+design -save gold
+muxpack
+opt
+stat
+select -assert-count 1 t:$pmux
+design -stash gate
+design -import gold -as gold
+design -import gate -as gate
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -verify -prove-asserts -show-ports miter
+
+design -load read
+hierarchy -top mux_if_unbal_5_3
+prep
+design -save gold
+muxpack
+opt
+stat
+select -assert-count 1 t:$pmux
+design -stash gate
+design -import gold -as gold
+design -import gate -as gate
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -verify -prove-asserts -show-ports miter
+
+design -load read
+hierarchy -top mux_if_unbal_5_3_invert
+prep
+design -save gold
+muxpack
+opt
+stat
+select -assert-count 1 t:$pmux
+design -stash gate
+design -import gold -as gold
+design -import gate -as gate
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -verify -prove-asserts -show-ports miter