From: Evan Cheng <evan.cheng@apple.com>
Date: Fri, 9 Mar 2007 09:48:56 +0000 (+0000)
Subject: If a virtual register is already marked alive in this block, that means it is
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e2ee99620fa6e428292737349d8e28bbcdcdaa0b;p=oota-llvm.git

If a virtual register is already marked alive in this block, that means it is
alive in one of the successor block. Do not add it to the kill list.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35041 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/LiveVariables.cpp b/lib/CodeGen/LiveVariables.cpp
index aec62dfcdf6..539799ec585 100644
--- a/lib/CodeGen/LiveVariables.cpp
+++ b/lib/CodeGen/LiveVariables.cpp
@@ -152,7 +152,12 @@ void LiveVariables::HandleVirtRegUse(VarInfo &VRInfo, MachineBasicBlock *MBB,
          "Should have kill for defblock!");
 
   // Add a new kill entry for this basic block.
-  VRInfo.Kills.push_back(MI);
+  unsigned BBNum = MBB->getNumber();
+  // If this virtual register is already marked as alive in this basic block,
+  // that means it is alive in at least one of the successor block, it's not
+  // a kill.
+  if (VRInfo.AliveBlocks.size() <= BBNum || !VRInfo.AliveBlocks[BBNum])
+    VRInfo.Kills.push_back(MI);
 
   // Update all dominating blocks to mark them known live.
   for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),