must not peephole away side effects

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113848 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/PeepholeOptimizer.cpp b/lib/CodeGen/PeepholeOptimizer.cpp
index 15ede91a38e72456ab03546b892477c99c21feda..28a4a9e301e6bfbef7df853f7cf4b4f1864f9434 100644 (file)
--- a/lib/CodeGen/PeepholeOptimizer.cpp
+++ b/lib/CodeGen/PeepholeOptimizer.cpp
@@ -269,7 +269,8 @@ bool PeepholeOptimizer::runOnMachineFunction(MachineFunction &MF) {
            MII = I->begin(), MIE = I->end(); MII != MIE; ) {
       MachineInstr *MI = &*MII;
 
-      if (MI->getDesc().isCompare()) {
+      if (MI->getDesc().isCompare() &&
+          !MI->getDesc().hasUnmodeledSideEffects()) {
         if (OptimizeCmpInstr(MI, MBB, MII))
           Changed = true;
         else