From a34bfa362972b5b30461c99ff545ee1ce69c483a Mon Sep 17 00:00:00 2001
From: Varun Koyyalagunta <vkoyyalagunta@tenstorrent.com>
Date: Mon, 5 Aug 2024 19:53:26 -0500
Subject: [PATCH] fix: case uniqueness checking

fixes #5319
incorporate feedback from https://github.com/verilator/verilator/pull/5324
---
 src/V3Assert.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/V3Assert.cpp b/src/V3Assert.cpp
index dff5f0f2d9..be16736b47 100644
--- a/src/V3Assert.cpp
+++ b/src/V3Assert.cpp
@@ -360,11 +360,12 @@ class AssertVisitor final : public VNVisitor {
                     //     else $error("multiple match");
                     // end
                     AstNodeExpr* const ohot = new AstOneHot{nodep->fileline(), propp};
+                    AstConst* const zero = new AstConst{nodep->fileline(), AstConst::WidthedValue{}, propp->width(), 0};
                     AstIf* const ohotIfp
                         = new AstIf{nodep->fileline(), new AstLogNot{nodep->fileline(), ohot}};
                     AstIf* const zeroIfp
                         = new AstIf{nodep->fileline(),
-                                    new AstLogNot{nodep->fileline(), propp->cloneTreePure(false)}};
+                                    new AstEq{nodep->fileline(), propp->cloneTreePure(false), zero}};
                     AstNodeExpr* const exprp = nodep->exprp();
                     const string pragmaStr = nodep->pragmaString();
                     if (!allow_none)