Fix comparison of unpacked arrays, bug1071.

Changes

@@ -10,6 +10,8 @@ indicates the contributor was also the author of the fix; Thanks!
 
 ****  Fix false warnings on non-power-2 enums using .next/.prev.
 
+****  Fix comparison of unpacked arrays, bug1071. [Andrew Bardsley]
+
 ****  Fix compiler warning in GCC 6. [David Horton]
 
 

src/V3Slice.cpp

@@ -471,6 +471,62 @@ class SliceVisitor : public AstNVisitor {
 	expandUniOp(nodep);
     }
 
+    void expandBiOp(AstNodeBiop* nodep) {
+	if (!nodep->user1()) {
+	    nodep->user1(true);
+	    // If it's a unpacked array, blow it up into comparing each element
+	    AstNodeDType* fromDtp = nodep->lhsp()->dtypep()->skipRefp();
+	    UINFO(9, "  Bi-Eq/Neq expansion "<<nodep<<endl);
+	    if (AstUnpackArrayDType* adtypep = fromDtp->castUnpackArrayDType()) {
+		AstNodeBiop* logp = NULL;
+		for (int index = adtypep->rangep()->lsbConst();
+		     index <= adtypep->rangep()->msbConst(); ++index) {
+		    // EQ(a,b) -> LOGAND(EQ(ARRAYSEL(a,0), ARRAYSEL(b,0)), ...[1])
+		    AstNodeBiop* clonep = nodep->cloneType
+			(new AstArraySel(nodep->fileline(),
+					 nodep->lhsp()->cloneTree(false),
+					 index),
+			 new AstArraySel(nodep->fileline(),
+					 nodep->rhsp()->cloneTree(false),
+					 index))->castNodeBiop();
+		    if (!logp) logp = clonep;
+		    else {
+			switch (nodep->type()) {
+			case AstType::atEQ:  // FALLTHRU
+			case AstType::atEQCASE:
+			    logp = new AstLogAnd(nodep->fileline(), logp, clonep);
+			    break;
+			case AstType::atNEQ:  // FALLTHRU
+			case AstType::atNEQCASE:
+			    logp = new AstLogOr(nodep->fileline(), logp, clonep);
+			    break;
+			default:
+			    nodep->v3fatalSrc("Unknown node type processing array slice");
+			    break;
+			}
+		    }
+		}
+		if (!logp) nodep->v3fatalSrc("Unpacked array with empty indices range");
+		nodep->replaceWith(logp);
+		pushDeletep(nodep); VL_DANGLING(nodep);
+		nodep = logp;
+	    }
+	    nodep->iterateChildren(*this);
+	}
+    }
+    virtual void visit(AstEq* nodep, AstNUser*) {
+	expandBiOp(nodep);
+    }
+    virtual void visit(AstNeq* nodep, AstNUser*) {
+	expandBiOp(nodep);
+    }
+    virtual void visit(AstEqCase* nodep, AstNUser*) {
+	expandBiOp(nodep);
+    }
+    virtual void visit(AstNeqCase* nodep, AstNUser*) {
+	expandBiOp(nodep);
+    }
+
     virtual void visit(AstNode* nodep, AstNUser*) {
 	// Default: Just iterate
 	nodep->iterateChildren(*this);

test_regress/t/t_EXAMPLE.v

@@ -13,7 +13,7 @@
 // please note it here, otherwise:**
 //
 // This file ONLY is placed into the Public Domain, for any use,
-// without warranty, 2015 by ____YOUR_NAME_HERE____.
+// without warranty, 2016 by ____YOUR_NAME_HERE____.
 
 module t (/*AUTOARG*/
    // Inputs

test_regress/t/t_array_compare.pl

@@ -0,0 +1,18 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003 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.
+
+compile (
+    );
+
+execute (
+    check_finished=>1,
+    );
+
+ok(1);
+1;

test_regress/t/t_array_compare.v

@@ -0,0 +1,58 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2016 by Andrew Bardsley.
+
+// bug1071
+
+module t (/*AUTOARG*/
+   // Inputs
+   clk
+   );
+   input clk;
+
+   reg [3:0] array_1 [2:0];
+   reg [3:0] array_2 [2:0];
+   reg [3:0] array_3 [3:1];
+
+   reg [3:0] elem;
+
+   reg array_1_ne_array_2;
+   reg array_1_eq_array_2;
+   reg array_1_ne_array_3;
+   reg array_1_eq_array_3;
+
+   initial begin
+      array_1[0] = 4'b1000;
+      array_1[1] = 4'b1000;
+      array_1[2] = 4'b1000;
+
+      array_2[0] = 4'b1000;
+      array_2[1] = 4'b1000;
+      array_2[2] = 4'b1000;
+
+      array_3[1] = 4'b1000;
+      array_3[2] = 4'b0100;
+      array_3[3] = 4'b0100;
+
+      // Comparisons only compare elements 0
+      array_1_ne_array_2 = array_1 != array_2;  // 0
+      array_1_eq_array_2 = array_1 == array_2;  // 0
+      array_1_ne_array_3 = array_1 != array_3;  // 1
+      array_1_eq_array_3 = array_1 == array_3;  // 1
+
+`ifdef TEST_VERBOSE
+      $write("array_1_ne_array2==%0d\n", array_1_ne_array_2);
+      $write("array_1_ne_array3==%0d\n", array_1_ne_array_3);
+`endif
+
+      if (array_1_ne_array_2 !== 0) $stop;
+      if (array_1_eq_array_2 !== 1) $stop;
+      if (array_1_ne_array_3 !== 1) $stop;
+      if (array_1_eq_array_3 !== 0) $stop;
+
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+
+endmodule