Detect and handle COPY in many places.

This code is transitional, it will soon be possible to eliminate
isExtractSubreg, isInsertSubreg, and isMoveInstr in most places.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107547 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/OptimizePHIs.cpp b/lib/CodeGen/OptimizePHIs.cpp
index 2717d4d..1613fe2 100644
--- a/lib/CodeGen/OptimizePHIs.cpp
+++ b/lib/CodeGen/OptimizePHIs.cpp
@@ -107,6 +107,11 @@
         SrcSubIdx == 0 && DstSubIdx == 0 &&
         TargetRegisterInfo::isVirtualRegister(MvSrcReg))
       SrcMI = MRI->getVRegDef(MvSrcReg);
+    else if (SrcMI && SrcMI->isCopy() &&
+             !SrcMI->getOperand(0).getSubReg() &&
+             !SrcMI->getOperand(1).getSubReg() &&
+           TargetRegisterInfo::isVirtualRegister(SrcMI->getOperand(1).getReg()))
+      SrcMI = MRI->getVRegDef(SrcMI->getOperand(1).getReg());
     if (!SrcMI)
       return false;