From: Cameron Zwarich <zwarich@apple.com>
Date: Thu, 30 Dec 2010 00:42:23 +0000 (+0000)
Subject: Use getVRegDef() instead of def_iterator. This leads to fewer defs being added
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=d16ad3e43c4dc59b3f6f8f36338a778f7c7a8701;p=oota-llvm.git

Use getVRegDef() instead of def_iterator. This leads to fewer defs being added
with 2-address instructions, for about a 3.5% speedup of StrongPHIElimination on
403.gcc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122635 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/StrongPHIElimination.cpp b/lib/CodeGen/StrongPHIElimination.cpp
index 87bb8034883..91ec13df643 100644
--- a/lib/CodeGen/StrongPHIElimination.cpp
+++ b/lib/CodeGen/StrongPHIElimination.cpp
@@ -233,10 +233,9 @@ bool StrongPHIElimination::runOnMachineFunction(MachineFunction& MF) {
         addReg(SrcReg);
         unionRegs(DestReg, SrcReg);
 
-        for (MachineRegisterInfo::def_iterator DI = MRI->def_begin(SrcReg),
-             DE = MRI->def_end(); DI != DE; ++DI) {
-          PHISrcDefs[DI->getParent()].push_back(&*DI);
-        }
+        MachineInstr* DefMI = MRI->getVRegDef(SrcReg);
+        if (DefMI)
+          PHISrcDefs[DefMI->getParent()].push_back(DefMI);
       }
     }
   }