From 0e2171904e1b1b0a95c43227617630bf5f8e7e11 Mon Sep 17 00:00:00 2001
From: Jacques Pienaar <jpienaar@google.com>
Date: Tue, 23 Aug 2016 01:04:41 +0000
Subject: [PATCH] [lanai] Exit early in Mem Alu combiner if sentinel reach.

LanaiMemAluCombiner could try to query the debug value of a list sentinel. Add check to exit early instead.

llvm-svn: 279497
---
 llvm/lib/Target/Lanai/LanaiMemAluCombiner.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/llvm/lib/Target/Lanai/LanaiMemAluCombiner.cpp b/llvm/lib/Target/Lanai/LanaiMemAluCombiner.cpp
index c5a4614..64e784b 100644
--- a/llvm/lib/Target/Lanai/LanaiMemAluCombiner.cpp
+++ b/llvm/lib/Target/Lanai/LanaiMemAluCombiner.cpp
@@ -339,6 +339,9 @@ MbbIterator LanaiMemAluCombiner::findClosestSuitableAluInstr(
   while (First != Last) {
     Decrement ? --First : ++First;
 
+    if (First == Last)
+      break;
+
     // Skip over debug instructions
     if (First->isDebugValue())
       continue;
-- 
2.7.4