From: Evan Cheng <evan.cheng@apple.com>
Date: Wed, 16 Apr 2008 18:01:08 +0000 (+0000)
Subject: Empty basic block should have an empty range.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=76249966eec8d318534b416f33f878c6bd01d1ee;p=oota-llvm.git

Empty basic block should have an empty range.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49800 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 9f72035bc90..d8ca141c669 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -108,7 +108,9 @@ bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) {
     }
 
     // Set the MBB2IdxMap entry for this MBB.
-    MBB2IdxMap[MBB->getNumber()] = std::make_pair(StartIdx, MIIndex - 1);
+    MBB2IdxMap[MBB->getNumber()] = (StartIdx == MIIndex)
+      ? std::make_pair(StartIdx, StartIdx)  // Empty MBB
+      : std::make_pair(StartIdx, MIIndex - 1);
     Idx2MBBMap.push_back(std::make_pair(StartIdx, MBB));
   }
   std::sort(Idx2MBBMap.begin(), Idx2MBBMap.end(), Idx2MBBCompare());