From 26769d5919168c999d6146fa72dcf0649c849873 Mon Sep 17 00:00:00 2001
From: Dan Gohman <gohman@apple.com>
Date: Tue, 11 Aug 2009 19:56:00 +0000
Subject: [PATCH] Don't set the isexact flag if an sdiv operator has been
 folded into something else.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78702 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/VMCore/Constants.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/VMCore/Constants.cpp b/lib/VMCore/Constants.cpp
index 70d43576a73..d71dc2cf710 100644
--- a/lib/VMCore/Constants.cpp
+++ b/lib/VMCore/Constants.cpp
@@ -607,7 +607,10 @@ Constant* ConstantVector::get(Constant* const* Vals, unsigned NumVals) {
 
 Constant* ConstantExpr::getExactSDiv(Constant* C1, Constant* C2) {
   Constant *C = getSDiv(C1, C2);
-  cast<SDivOperator>(C)->setIsExact(true);
+  // Set exact attribute, assuming constant folding didn't eliminate the
+  // SDiv.
+  if (SDivOperator *SDiv = dyn_cast<SDivOperator>(C))
+    SDiv->setIsExact(true);
   return C;
 }