Merge pull request #1397 from larsclausen/draw-net-input-mux-array-port

tgt-vvp: Avoid interleaving array ports into mux output

ivtest/ivltests/case_mux_array_word.v

@@ -0,0 +1,52 @@
+// Check that case statement muxes work with array word inputs.
+
+module test;
+
+  reg [7:0] mem [0:3];
+  reg [1:0] sel;
+  reg [7:0] out;
+  reg failed;
+
+  `define check(val, exp) \
+    if (val !== exp) begin \
+      $display("FAILED(%0d). '%s' expected %b, got %b", `__LINE__, \
+               `"val`", exp, val); \
+      failed = 1'b1; \
+    end
+
+  always @* begin
+    case (sel)
+      2'd0: out = mem[0];
+      2'd1: out = mem[1];
+      2'd2: out = mem[2];
+      2'd3: out = mem[3];
+    endcase
+  end
+
+  (* ivl_synthesis_off *)
+  initial begin
+    failed = 1'b0;
+
+    mem[0] = 8'h12;
+    mem[1] = 8'h34;
+    mem[2] = 8'h56;
+    mem[3] = 8'h78;
+
+    sel = 2'd0;
+    #1 `check(out, 8'h12);
+
+    sel = 2'd1;
+    #1 `check(out, 8'h34);
+
+    sel = 2'd2;
+    #1 `check(out, 8'h56);
+
+    sel = 2'd3;
+    #1 `check(out, 8'h78);
+
+    if (!failed) begin
+      $display("PASSED");
+    end
+  end
+
+endmodule

ivtest/regress-vvp.list

@@ -92,6 +92,7 @@ case1				vvp_tests/case1.json
 case2				vvp_tests/case2.json
 case2-S				vvp_tests/case2-S.json
 case3				vvp_tests/case3.json
+case_mux_array_word		vvp_tests/case_mux_array_word.json
 casex_synth			vvp_tests/casex_synth.json
 cast_int_ams			vvp_tests/cast_int_ams.json
 cast_real_invalid1		vvp_tests/cast_real_invalid1.json

ivtest/vvp_tests/case_mux_array_word.json

@@ -0,0 +1,5 @@
+{
+    "type"   : "normal",
+    "source" : "case_mux_array_word.v",
+    "iverilog-args" : [ "-S" ]
+}

tgt-vvp/draw_mux.c

@@ -83,10 +83,14 @@ static void draw_lpm_mux_nest(ivl_lpm_t net, const char*muxz)
 	      net, select_input);
 
       for (idx = 0 ;  idx < ivl_lpm_size(net) ;  idx += 2) {
+	      /* draw_net_input() can emit helper statements, for example for
+		 array words. Emit those before starting the .functor line. */
+	    const char*input0 = draw_net_input(ivl_lpm_data(net,idx+0));
+	    const char*input1 = draw_net_input(ivl_lpm_data(net,idx+1));
 	    fprintf(vvp_out, "L_%p/0/%u .functor %s %u",
 		    net, idx/2, muxz, width);
-	    fprintf(vvp_out, ", %s", draw_net_input(ivl_lpm_data(net,idx+0)));
-	    fprintf(vvp_out, ", %s", draw_net_input(ivl_lpm_data(net,idx+1)));
+	    fprintf(vvp_out, ", %s", input0);
+	    fprintf(vvp_out, ", %s", input1);
 	    fprintf(vvp_out, ", L_%p/0s, C4<>;\n", net);
       }
 

tgt-vvp/draw_substitute.c

@@ -25,8 +25,13 @@
 void draw_lpm_substitute(ivl_lpm_t net)
 {
       unsigned swidth = width_of_nexus(ivl_lpm_data(net,1));
+      /* draw_net_input() can emit helper statements, for example for
+	 array words. Emit those before starting the .substitute line. */
+      const char*input0 = draw_net_input(ivl_lpm_data(net,0));
+      const char*input1 = draw_net_input(ivl_lpm_data(net,1));
+
       fprintf(vvp_out, "L_%p .substitute %u, %u %u",
 	      net, ivl_lpm_width(net), ivl_lpm_base(net), swidth);
-      fprintf(vvp_out, ", %s", draw_net_input(ivl_lpm_data(net,0)));
-      fprintf(vvp_out, ", %s;\n", draw_net_input(ivl_lpm_data(net,1)));
+      fprintf(vvp_out, ", %s", input0);
+      fprintf(vvp_out, ", %s;\n", input1);
 }