From 666cf56668e5be83c4e8424c188f727a6b852312 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Tue, 22 Feb 2011 07:07:59 +0000
Subject: [PATCH] Guard against de-referencing MBB.end().

llvm-svn: 126192
---
 llvm/lib/Target/ARM/Thumb2InstrInfo.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/Target/ARM/Thumb2InstrInfo.cpp b/llvm/lib/Target/ARM/Thumb2InstrInfo.cpp
index 836c1baffd40..9b1073be3c8e 100644
--- a/llvm/lib/Target/ARM/Thumb2InstrInfo.cpp
+++ b/llvm/lib/Target/ARM/Thumb2InstrInfo.cpp
@@ -95,8 +95,11 @@ Thumb2InstrInfo::ReplaceTailWithBranchTo(MachineBasicBlock::iterator Tail,
 bool
 Thumb2InstrInfo::isLegalToSplitMBBAt(MachineBasicBlock &MBB,
                                      MachineBasicBlock::iterator MBBI) const {
-  while (MBBI->isDebugValue())
+  while (MBBI->isDebugValue()) {
     ++MBBI;
+    if (MBBI == MBB.end())
+      return false;
+  }
 
   unsigned PredReg = 0;
   return llvm::getITInstrPredicate(MBBI, PredReg) == ARMCC::AL;