From fd50d76ff854e8e60aa22b0db609de359ff3a576 Mon Sep 17 00:00:00 2001
From: Jakob Stoklund Olesen <stoklund@2pi.dk>
Date: Thu, 20 Jan 2011 06:20:02 +0000
Subject: [PATCH] Check that a live range exists before shortening it. This
 fixes PR8989.

The live range may have been deleted earlier because of rematerialization.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123891 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SimpleRegisterCoalescing.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index e616d3536fe..a859f6e0745 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -1685,9 +1685,11 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
           DoDelete = false;
         
         if (MI->allDefsAreDead()) {
-          LiveInterval &li = li_->getInterval(SrcReg);
-          if (!ShortenDeadCopySrcLiveRange(li, MI))
-            ShortenDeadCopyLiveRange(li, MI);
+          if (li_->hasInterval(SrcReg)) {
+            LiveInterval &li = li_->getInterval(SrcReg);
+            if (!ShortenDeadCopySrcLiveRange(li, MI))
+              ShortenDeadCopyLiveRange(li, MI);
+          }
           DoDelete = true;
         }
         if (!DoDelete) {