[LiveRangeEdit] Add a statistic variable for rematerialization

[Carrot]

Summary

Add a statistic variable for rematerialization.

[arsenm]

LGTM with spelling nit

llvm/lib/CodeGen/LiveRangeEdit.cpp

30

s/rematerialization/instructions rematerialized/

[Carrot]

Thanks for the quick review. Will check in this version.

llvm/lib/CodeGen/LiveRangeEdit.cpp

 #include "llvm/CodeGen/VirtRegMap.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 
 using namespace llvm;
 
 #define DEBUG_TYPE "regalloc"
 
-STATISTIC(NumDCEDeleted,     "Number of instructions deleted by DCE");
-STATISTIC(NumDCEFoldedLoads, "Number of single use loads folded after DCE");
-STATISTIC(NumFracRanges,     "Number of live ranges fractured by DCE");
+STATISTIC(NumDCEDeleted,        "Number of instructions deleted by DCE");
+STATISTIC(NumDCEFoldedLoads,    "Number of single use loads folded after DCE");
+STATISTIC(NumFracRanges,        "Number of live ranges fractured by DCE");
+STATISTIC(NumReMaterialization, "Number of instructions rematerialized");
 
 void LiveRangeEdit::Delegate::anchor() { }
 
 LiveInterval &LiveRangeEdit::createEmptyIntervalFrom(Register OldReg,
                                                      bool createSubRanges) {
   Register VReg = MRI.createVirtualRegister(MRI.getRegClass(OldReg));
   if (VRM)
     VRM->setIsSplitFromReg(VReg, VRM->getOriginal(OldReg));
SlotIndex LiveRangeEdit::rematerializeAt(MachineBasicBlock &MBB,
                                          MachineInstr *ReplaceIndexMI) {
   assert(RM.OrigMI && "Invalid remat");
   TII.reMaterialize(MBB, MI, DestReg, SubIdx, *RM.OrigMI, tri);
   // DestReg of the cloned instruction cannot be Dead. Set isDead of DestReg
   // to false anyway in case the isDead flag of RM.OrigMI's dest register
   // is true.
   (*--MI).getOperand(0).setIsDead(false);
   Rematted.insert(RM.ParentVNI);
+  ++NumReMaterialization;
+
   if (ReplaceIndexMI)
     return LIS.ReplaceMachineInstrInMaps(*ReplaceIndexMI, *MI).getRegSlot();
   return LIS.getSlotIndexes()->insertMachineInstrInMaps(*MI, Late).getRegSlot();
 }
 
 void LiveRangeEdit::eraseVirtReg(Register Reg) {
   if (TheDelegate && TheDelegate->LRE_CanEraseVirtReg(Reg))
     LIS.removeInterval(Reg);