From 92106641ae297c24877085e0357e8095aa7b43c9 Mon Sep 17 00:00:00 2001
From: Juneyoung Lee <aqjune@gmail.com>
Date: Fri, 25 Sep 2020 09:49:13 +0900
Subject: [PATCH] [ValueTracking] Make isGuaranteedNotToBeUndefOrPoison exit
 early when MetadataAsValue is given

It is set to conservatively return false, otherwise noundef attributes are added to function calls with metadata arguments.
---
 llvm/lib/Analysis/ValueTracking.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 682baacac3a9..ac8386900a11 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -4881,6 +4881,9 @@ static bool isGuaranteedNotToBeUndefOrPoison(const Value *V,
   if (Depth >= MaxAnalysisRecursionDepth)
     return false;
 
+  if (isa<MetadataAsValue>(V))
+    return false;
+
   if (const auto *A = dyn_cast<Argument>(V)) {
     if (A->hasAttribute(Attribute::NoUndef))
       return true;