From d096479f31eb51bcbd418b6e852a34210141d80e Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Tue, 26 Jun 2012 22:54:59 +0000
Subject: [PATCH] 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
---
 lib/Target/ARM/ARMBaseInstrInfo.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/Target/ARM/ARMBaseInstrInfo.cpp b/lib/Target/ARM/ARMBaseInstrInfo.cpp
index 58f4e160de8..3a180dfa279 100644
--- a/lib/Target/ARM/ARMBaseInstrInfo.cpp
+++ b/lib/Target/ARM/ARMBaseInstrInfo.cpp
@@ -1802,6 +1802,8 @@ static bool isSuitableForMask(MachineInstr *&MI, unsigned SrcReg,
 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())
-- 
2.34.1