From 4a8dbc617d0b28ce2ce3e6856376b3802409554e Mon Sep 17 00:00:00 2001 From: Daniil Suchkov Date: Tue, 21 Jan 2020 12:21:53 +0700 Subject: [PATCH] [SSAUpdater] Don't call ValueIsRAUWd upon single use replacement It is incorrect to call ValueHandleBase::ValueIsRAUWd when only one use is replaced since it simply violates semantics of the callback and leads to bugs like PR44320. Previously this call was used specifically to keep LICM's cache of AliasSetTrackers up to date across passes (as PR36801 showed, even for that purpose it didn't work properly), but since LICM doesn't have that cache anymore, we can safely remove this incorrect call with no repercussions. This patch fixes https://bugs.llvm.org/show_bug.cgi?id=44320 Reviewers: asbirlea, fhahn, efriedma, reames Reviewed-By: asbirlea Differential Revision: https://reviews.llvm.org/D73089 --- llvm/lib/Transforms/Utils/SSAUpdater.cpp | 5 ----- llvm/test/Transforms/LCSSA/pr44320.ll | 1 - 2 files changed, 6 deletions(-) diff --git a/llvm/lib/Transforms/Utils/SSAUpdater.cpp b/llvm/lib/Transforms/Utils/SSAUpdater.cpp index bffdd115d940..36a17ce76198 100644 --- a/llvm/lib/Transforms/Utils/SSAUpdater.cpp +++ b/llvm/lib/Transforms/Utils/SSAUpdater.cpp @@ -195,11 +195,6 @@ void SSAUpdater::RewriteUse(Use &U) { else V = GetValueInMiddleOfBlock(User->getParent()); - // Notify that users of the existing value that it is being replaced. - Value *OldVal = U.get(); - if (OldVal != V && OldVal->hasValueHandle()) - ValueHandleBase::ValueIsRAUWd(OldVal, V); - U.set(V); } diff --git a/llvm/test/Transforms/LCSSA/pr44320.ll b/llvm/test/Transforms/LCSSA/pr44320.ll index a211cf82cc89..b6082ac96ed7 100644 --- a/llvm/test/Transforms/LCSSA/pr44320.ll +++ b/llvm/test/Transforms/LCSSA/pr44320.ll @@ -1,4 +1,3 @@ -; XFAIL: * ; RUN: opt -passes="verify,lcssa,verify" -verify-scev-strict -S -disable-output %s ; The first SCEV verification is required because it queries SCEV and populates