From: Andrew Trick <atrick@apple.com>
Date: Wed, 1 Jun 2011 19:14:56 +0000 (+0000)
Subject: SCEV: missing null check fix for r132360, dragonegg crash.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=cf31f91931b257462a5a0059389977f6adea8dae;p=oota-llvm.git

SCEV: missing null check fix for r132360, dragonegg crash.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132416 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp
index ef390c5a3ee..025718e09fe 100644
--- a/lib/Analysis/ScalarEvolution.cpp
+++ b/lib/Analysis/ScalarEvolution.cpp
@@ -1081,9 +1081,8 @@ static const SCEV *getPreStartForSignExtend(const SCEVAddRecExpr *AR,
   const SCEVAddRecExpr *PreAR = dyn_cast<SCEVAddRecExpr>(
     SE->getAddRecExpr(PreStart, Step, L, SCEV::FlagAnyWrap));
 
-  if (PreAR && PreAR->getNoWrapFlags(SCEV::FlagNSW)) {
+  if (PreAR && PreAR->getNoWrapFlags(SCEV::FlagNSW))
     return PreStart;
-  }
 
   // 2. Direct overflow check on the step operation's expression.
   unsigned BitWidth = SE->getTypeSizeInBits(AR->getType());
@@ -1104,7 +1103,8 @@ static const SCEV *getPreStartForSignExtend(const SCEVAddRecExpr *AR,
   ICmpInst::Predicate Pred;
   const SCEV *OverflowLimit = getOverflowLimitForStep(Step, &Pred, SE);
 
-  if (SE->isLoopEntryGuardedByCond(L, Pred, PreStart, OverflowLimit)) {
+  if (OverflowLimit &&
+      SE->isLoopEntryGuardedByCond(L, Pred, PreStart, OverflowLimit)) {
     return PreStart;
   }
   return 0;