From d059806dbdfe76596063ad84444d7a313f419a62 Mon Sep 17 00:00:00 2001
From: Geza Lore <gezalore@gmail.com>
Date: Sun, 15 Jun 2025 18:12:37 +0100
Subject: [PATCH] Fix Dfg eliminateVar pass to remove more variables (#6091)

Failing to reset the work list pointer in vertices leads to not removing
some redundant variables if they become redundant after having been
considered once already.
---
 src/V3DfgPasses.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/V3DfgPasses.cpp b/src/V3DfgPasses.cpp
index 5c82ba149..5b6ffb81a 100644
--- a/src/V3DfgPasses.cpp
+++ b/src/V3DfgPasses.cpp
@@ -263,6 +263,8 @@ void V3DfgPasses::eliminateVars(DfgGraph& dfg, V3DfgEliminateVarsContext& ctx) {
         DfgVertex* const vtxp = workListp;
         // Detach the head
         workListp = vtxp->getUser<DfgVertex*>();
+        // Reset user pointer so it can be added back to the work list later
+        vtxp->setUser<DfgVertex*>(nullptr);
         // Prefetch next item
         VL_PREFETCH_RW(workListp);