[llvm] r184569 - Fix a -join-globalcopies bug; handle undef operands.

[Andrew Trick]

Author: atrick
Date: Fri Jun 21 13:33:11 2013
New Revision: 184569

URL: http://llvm.org/viewvc/llvm-project?rev=184569&view=rev
Log:
Fix a -join-globalcopies bug; handle undef operands.

Modified:
    llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp

Modified: llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp?rev=184569&r1=184568&r2=184569&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp (original)
+++ llvm/trunk/lib/CodeGen/RegisterCoalescer.cpp Fri Jun 21 13:33:11 2013
@@ -2072,6 +2072,9 @@ static bool isLocalCopy(MachineInstr *Co
   if (!Copy->isCopy())
     return false;
 
+  if (Copy->getOperand(1).isUndef())
+    return false;
+
   unsigned SrcReg = Copy->getOperand(1).getReg();
   unsigned DstReg = Copy->getOperand(0).getReg();
   if (TargetRegisterInfo::isPhysicalRegister(SrcReg)