From: Evan Cheng <evan.cheng@apple.com>
Date: Wed, 16 Nov 2011 03:47:42 +0000 (+0000)
Subject: If the 2addr instruction has other kills, don't move it below any other uses since... 
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=9bad88a9def4abaa87e7e5e7178bd680354043f8;p=oota-llvm.git

If the 2addr instruction has other kills, don't move it below any other uses since we don't want to extend other live ranges.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144772 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/TwoAddressInstructionPass.cpp b/lib/CodeGen/TwoAddressInstructionPass.cpp
index 3e9a0e44e93..7a0fcb5651c 100644
--- a/lib/CodeGen/TwoAddressInstructionPass.cpp
+++ b/lib/CodeGen/TwoAddressInstructionPass.cpp
@@ -933,6 +933,7 @@ TwoAddressInstructionPass::RescheduleMIBelowKill(MachineBasicBlock *MBB,
     return false;
 
   SmallSet<unsigned, 2> Uses;
+  SmallSet<unsigned, 2> Kills;
   SmallSet<unsigned, 2> Defs;
   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
     const MachineOperand &MO = MI->getOperand(i);
@@ -943,8 +944,11 @@ TwoAddressInstructionPass::RescheduleMIBelowKill(MachineBasicBlock *MBB,
       continue;
     if (MO.isDef())
       Defs.insert(MOReg);
-    else
+    else {
       Uses.insert(MOReg);
+      if (MO.isKill() && MOReg != Reg)
+        Kills.insert(MOReg);
+    }
   }
 
   // Move the copies connected to MI down as well.
@@ -991,7 +995,8 @@ TwoAddressInstructionPass::RescheduleMIBelowKill(MachineBasicBlock *MBB,
       } else {
         if (Defs.count(MOReg))
           return false;
-        if (MOReg != Reg && MO.isKill() && Uses.count(MOReg))
+        if (MOReg != Reg &&
+            ((MO.isKill() && Uses.count(MOReg)) || Kills.count(MOReg)))
           // Don't want to extend other live ranges and update kills.
           return false;
       }