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

2 files changed, 14 insertions, 3 deletions

diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp
index 4e6c4c705d..04f92adefd 100644
--- a/lib/CodeGen/LiveRangeEdit.cpp
+++ b/lib/CodeGen/LiveRangeEdit.cpp
@@ -33,11 +33,9 @@ void LiveRangeEdit::Delegate::anchor() { }
 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 @@ void LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr*> &Dead,
   }
 }
 
+// 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,
diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index 7f2c0caca4..ce7d567cc2 100644
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -20,7 +20,7 @@
 using namespace llvm;
 
 MachineRegisterInfo::MachineRegisterInfo(const TargetMachine &TM)
-  : TM(TM), IsSSA(true), TracksLiveness(true) {
+  : TM(TM), TheDelegate(0), IsSSA(true), TracksLiveness(true) {
   VRegInfo.reserve(256);
   RegAllocHints.reserve(256);
   UsedRegUnits.resize(getTargetRegisterInfo()->getNumRegUnits());
@@ -108,6 +108,8 @@ MachineRegisterInfo::createVirtualRegister(const TargetRegisterClass *RegClass){
   VRegInfo.grow(Reg);
   VRegInfo[Reg].first = RegClass;
   RegAllocHints.grow(Reg);
+  if (TheDelegate)
+    TheDelegate->MRI_NoteNewVirtualRegister(Reg);
   return Reg;
 }