[MergedLoadStoreMotion] Use correct helper for load hoist safety.

It isn't legal to hoist a load past a call which might not return;
even if it doesn't throw, it could, for example, call exit().

Fixes http://llvm.org/PR27953.

llvm-svn: 272495

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp b/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
index e300c9f65d9..6010c80cd93 100644
--- a/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
+++ b/llvm/lib/Transforms/Scalar/MergedLoadStoreMotion.cpp
@@ -79,6 +79,7 @@
 #include "llvm/Analysis/Loads.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
 #include "llvm/Analysis/MemoryDependenceAnalysis.h"
+#include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/Metadata.h"
 #include "llvm/IR/PatternMatch.h"
 #include "llvm/Support/Debug.h"
@@ -232,7 +233,7 @@ bool MergedLoadStoreMotion::isLoadHoistBarrierInRange(
   if (!SafeToLoadUnconditionally)
     for (const Instruction &Inst :
          make_range(Start.getIterator(), End.getIterator()))
-      if (Inst.mayThrow())
+      if (!isGuaranteedToTransferExecutionToSuccessor(&Inst))
         return true;
   MemoryLocation Loc = MemoryLocation::get(LI);
   return AA->canInstructionRangeModRef(Start, End, Loc, MRI_Mod);