From 9b06310cbeb59abf1af06cfd1cc3150b14e83cac Mon Sep 17 00:00:00 2001
From: Wilson Snyder <wsnyder@wsnyder.org>
Date: Sat, 3 Dec 2016 14:49:51 -0500
Subject: [PATCH] Fix internal error on unique casez with --assert, bug1117.

---
 Changes                          |  2 ++
 src/V3Assert.cpp                 | 23 ++++++++++++++++++++---
 test_regress/t/t_assert_casez.pl | 19 +++++++++++++++++++
 test_regress/t/t_assert_casez.v  | 26 ++++++++++++++++++++++++++
 4 files changed, 67 insertions(+), 3 deletions(-)
 create mode 100755 test_regress/t/t_assert_casez.pl
 create mode 100644 test_regress/t/t_assert_casez.v

diff --git a/Changes b/Changes
index 7b91b9fb4..d64edbe9a 100644
--- a/Changes
+++ b/Changes
@@ -7,6 +7,8 @@ The contributors that suggested a given feature are shown in []. Thanks!
 
 ****  Fix internal error on double-for loop unrolling, bug1044. [Jan Egil Ruud]
 
+****  Fix internal error on unique casez with --assert, bug1117. [Enzo Chi]
+
 
 * Verilator 3.890 2016-11-25
 
diff --git a/src/V3Assert.cpp b/src/V3Assert.cpp
index 273570031..b92a4540f 100644
--- a/src/V3Assert.cpp
+++ b/src/V3Assert.cpp
@@ -245,9 +245,26 @@ private:
 		    AstNode* propp = NULL;
 		    for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
 			for (AstNode* icondp = itemp->condsp(); icondp!=NULL; icondp=icondp->nextp()) {
-			    AstNode* onep = new AstEq(icondp->fileline(),
-						      nodep->exprp()->cloneTree(false),
-						      icondp->cloneTree(false));
+			    AstNode* onep;
+			    AstConst* iconstp = icondp->castConst();
+			    if (iconstp && iconstp->num().isFourState()
+				&& (nodep->casex() || nodep->casez() || nodep->caseInside())) {
+				V3Number nummask (itemp->fileline(), iconstp->width());
+				nummask.opBitsNonX(iconstp->num());
+				V3Number numval  (itemp->fileline(), iconstp->width());
+				numval.opBitsOne(iconstp->num());
+				AstNode* and1p = new AstAnd(itemp->fileline(), nodep->exprp()->cloneTree(false),
+							    new AstConst(itemp->fileline(), nummask));
+				AstNode* and2p = new AstAnd(itemp->fileline(),
+							    new AstConst(itemp->fileline(), numval),
+							    new AstConst(itemp->fileline(), nummask));
+				onep = AstEq::newTyped(itemp->fileline(), and1p, and2p);
+
+			    } else {
+				onep = AstEq::newTyped(icondp->fileline(),
+						       nodep->exprp()->cloneTree(false),
+						       icondp->cloneTree(false));
+			    }
 			    if (propp) propp = new AstConcat(icondp->fileline(), onep, propp);
 			    else propp = onep;
 			}
diff --git a/test_regress/t/t_assert_casez.pl b/test_regress/t/t_assert_casez.pl
new file mode 100755
index 000000000..b57b2dea8
--- /dev/null
+++ b/test_regress/t/t_assert_casez.pl
@@ -0,0 +1,19 @@
+#!/usr/bin/perl
+if (!$::Driver) { use FindBin; exec("$FindBin::Bin/bootstrap.pl", @ARGV, $0); die; }
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2003-2009 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 (
+    verilator_flags2 => ['--assert'],
+    );
+
+execute (
+    check_finished=>1,
+    );
+
+ok(1);
+1;
diff --git a/test_regress/t/t_assert_casez.v b/test_regress/t/t_assert_casez.v
new file mode 100644
index 000000000..106a8ebd8
--- /dev/null
+++ b/test_regress/t/t_assert_casez.v
@@ -0,0 +1,26 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2016 by Wilson Snyder
+
+module t;
+
+   reg [1:0] value;
+
+   initial begin
+      value = 2'b00;
+      unique casez (value)
+        2'b00 : ;
+        2'b01 : ;
+        2'b1? : ;
+      endcase
+      value = 2'b11;
+      unique casez (value)
+        2'b00 : ;
+        2'b01 : ;
+        2'b1? : ;
+      endcase
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule