Notify LiveRangeEdit of new virtual registers.

Add a delegate class to MachineRegisterInfo with a single virtual
function, MRI_NoteNewVirtualRegister(). Update LiveRangeEdit to inherit
from this delegate class and override the definition of the callback
with an implementation that tracks the newly created virtual registers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188435 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp
index 4e6c4c7..04f92ad 100644
--- a/lib/CodeGen/LiveRangeEdit.cpp
+++ b/lib/CodeGen/LiveRangeEdit.cpp
@@ -33,11 +33,9 @@
 LiveInterval &LiveRangeEdit::createFrom(unsigned OldReg) {
   unsigned VReg = MRI.createVirtualRegister(MRI.getRegClass(OldReg));
   if (VRM) {
-    VRM->grow();
     VRM->setIsSplitFromReg(VReg, VRM->getOriginal(OldReg));
   }
   LiveInterval &LI = LIS.getOrCreateInterval(VReg);
-  NewRegs.push_back(VReg);
   return LI;
 }
 
@@ -387,6 +385,17 @@
   }
 }
 
+// Keep track of new virtual registers created via
+// MachineRegisterInfo::createVirtualRegister.
+void
+LiveRangeEdit::MRI_NoteNewVirtualRegister(unsigned VReg)
+{
+  if (VRM)
+    VRM->grow();
+
+  NewRegs.push_back(VReg);
+}
+
 void
 LiveRangeEdit::calculateRegClassAndHint(MachineFunction &MF,
                                         const MachineLoopInfo &Loops,