Add a missing check to avoid dereference null. No sensible test case possible. Sorry. rdar://11745134
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159236 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
index 58f4e16..3a180df 100644
--- a/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -1802,6 +1802,8 @@
bool ARMBaseInstrInfo::
OptimizeCompareInstr(MachineInstr *CmpInstr, unsigned SrcReg, int CmpMask,
int CmpValue, const MachineRegisterInfo *MRI) const {
+ if (MRI->def_empty(SrcReg))
+ return false;
MachineRegisterInfo::def_iterator DI = MRI->def_begin(SrcReg);
if (llvm::next(DI) != MRI->def_end())