isSubRegOf() is a dup of isSubRegister.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43249 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LowerSubregs.cpp b/lib/CodeGen/LowerSubregs.cpp
index ba2a193..1b7f70e 100644
--- a/lib/CodeGen/LowerSubregs.cpp
+++ b/lib/CodeGen/LowerSubregs.cpp
@@ -146,7 +146,7 @@
   // of the destination, we copy the subreg into the source
   // However, this is only safe if the insert instruction is the kill
   // of the source register
-  bool revCopyOrder = MRI.isSubRegOf(InsReg, DstReg);    
+  bool revCopyOrder = MRI.isSubRegister(DstReg, InsReg);
   if (revCopyOrder && InsReg != DstSubReg) {
     if (MI->getOperand(1).isKill()) {
       DstSubReg = MRI.getSubReg(SrcReg, SubIdx);