Tests: Add iff test, bug1482.

test_regress/t/t_iff.pl

@@ -0,0 +1,21 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2019 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+
+scenarios(simulator => 1);
+$Self->{vlt_all} and unsupported("Verilator unsupported, bug1482, iff not supported");
+
+compile(
+    );
+
+execute(
+    check_finished => 1,
+    );
+
+ok(1);
+1;

test_regress/t/t_iff.v

@@ -0,0 +1,87 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// Use this file as a template for submitting bugs, etc.
+// This module takes a single clock input, and should either
+//      $write("*-* All Finished *-*\n");
+//      $finish;
+// on success, or $stop.
+//
+// The code as shown applies a random vector to the Test
+// module, then calculates a CRC on the Test module's outputs.
+//
+// **If you do not wish for your code to be released to the public
+// please note it here, otherwise:**
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2019 by ____YOUR_NAME_HERE____.
+
+module t (/*AUTOARG*/
+   // Inputs
+   clk
+   );
+   input clk;
+
+   integer      cyc=0;
+   reg [63:0]   crc;
+   reg [63:0]   sum;
+
+   /*AUTOWIRE*/
+   // Beginning of automatic wires (for undeclared instantiated-module outputs)
+   wire [31:0]          result;                 // From test of Test.v
+   // End of automatics
+   Test test (.*);
+
+   // Test loop
+   always @ (posedge clk) begin
+`ifdef TEST_VERBOSE
+      $write("[%0t] cyc==%0d crc=%x result=%x\n",$time, cyc, crc, result);
+`endif
+      cyc <= cyc + 1;
+      crc <= {crc[62:0], crc[63]^crc[2]^crc[0]};
+      sum <= result ^ {sum[62:0],sum[63]^sum[2]^sum[0]};
+      if (cyc==0) begin
+         // Setup
+         crc <= 64'h5aef0c8d_d70a4497;
+         sum <= '0;
+      end
+      else if (cyc<10) begin
+         sum <= '0;
+      end
+      else if (cyc<90) begin
+      end
+      else if (cyc==99) begin
+         $write("[%0t] cyc==%0d crc=%x sum=%x\n",$time, cyc, crc, sum);
+         if (crc !== 64'hc77bb9b3784ea091) $stop;
+         // What checksum will we end up with (above print should match)
+`define EXPECTED_SUM 64'he58508de5310b541
+         if (sum !== `EXPECTED_SUM) $stop;
+         $write("*-* All Finished *-*\n");
+         $finish;
+      end
+   end
+
+endmodule
+
+module Test
+  (
+   input              clk,
+   input [63:0]       crc,
+   input [31:0]       cyc,
+   output wire [31:0] result);
+
+   wire         enable = crc[32];
+   wire [31:0]  d = crc[31:0];
+   logic [31:0] y;
+   always @(d iff enable == 1) begin
+      y <= d;
+   end
+
+   wire reset = (cyc < 10);
+   assert property (@(posedge clk iff enable)
+                    disable iff (reset)
+                    (crc != '0));
+
+   // Aggregate outputs into a single result vector
+   assign result = {32'h0, y};
+
+endmodule