1 files changed, 31 insertions, 12 deletions

diff --git a/lib/CodeGen/TailDuplication.cpp b/lib/CodeGen/TailDuplication.cpp
index d6860bc..3223e53 100644
--- a/lib/CodeGen/TailDuplication.cpp
+++ b/lib/CodeGen/TailDuplication.cpp
@@ -121,7 +121,7 @@ static void VerifyPHIs(MachineFunction &MF, bool CheckExtra) {
                                                 MBB->pred_end());
     MachineBasicBlock::iterator MI = MBB->begin();
     while (MI != MBB->end()) {
-      if (MI->getOpcode() != TargetInstrInfo::PHI)
+      if (!MI->isPHI())
         break;
       for (SmallSetVector<MachineBasicBlock *, 8>::iterator PI = Preds.begin(),
              PE = Preds.end(); PI != PE; ++PI) {
@@ -378,7 +378,7 @@ TailDuplicatePass::UpdateSuccessorsPHIs(MachineBasicBlock *FromBB, bool isDead,
     MachineBasicBlock *SuccBB = *SI;
     for (MachineBasicBlock::iterator II = SuccBB->begin(), EE = SuccBB->end();
          II != EE; ++II) {
-      if (II->getOpcode() != TargetInstrInfo::PHI)
+      if (!II->isPHI())
         break;
       unsigned Idx = 0;
       for (unsigned i = 1, e = II->getNumOperands(); i != e; i += 2) {
@@ -403,26 +403,45 @@ TailDuplicatePass::UpdateSuccessorsPHIs(MachineBasicBlock *FromBB, bool isDead,
             II->RemoveOperand(i);
           }
         }
-        II->RemoveOperand(Idx+1);
-        II->RemoveOperand(Idx);
-      }
+      } else
+        Idx = 0;
+
+      // If Idx is set, the operands at Idx and Idx+1 must be removed.
+      // We reuse the location to avoid expensive RemoveOperand calls.
+
       DenseMap<unsigned,AvailableValsTy>::iterator LI=SSAUpdateVals.find(Reg);
       if (LI != SSAUpdateVals.end()) {
         // This register is defined in the tail block.
         for (unsigned j = 0, ee = LI->second.size(); j != ee; ++j) {
           MachineBasicBlock *SrcBB = LI->second[j].first;
           unsigned SrcReg = LI->second[j].second;
-          II->addOperand(MachineOperand::CreateReg(SrcReg, false));
-          II->addOperand(MachineOperand::CreateMBB(SrcBB));
+          if (Idx != 0) {
+            II->getOperand(Idx).setReg(SrcReg);
+            II->getOperand(Idx+1).setMBB(SrcBB);
+            Idx = 0;
+          } else {
+            II->addOperand(MachineOperand::CreateReg(SrcReg, false));
+            II->addOperand(MachineOperand::CreateMBB(SrcBB));
+          }
         }
       } else {
         // Live in tail block, must also be live in predecessors.
         for (unsigned j = 0, ee = TDBBs.size(); j != ee; ++j) {
           MachineBasicBlock *SrcBB = TDBBs[j];
-          II->addOperand(MachineOperand::CreateReg(Reg, false));
-          II->addOperand(MachineOperand::CreateMBB(SrcBB));
+          if (Idx != 0) {
+            II->getOperand(Idx).setReg(Reg);
+            II->getOperand(Idx+1).setMBB(SrcBB);
+            Idx = 0;
+          } else {
+            II->addOperand(MachineOperand::CreateReg(Reg, false));
+            II->addOperand(MachineOperand::CreateMBB(SrcBB));
+          }
         }
       }
+      if (Idx != 0) {
+        II->RemoveOperand(Idx+1);
+        II->RemoveOperand(Idx);
+      }
     }
   }
 }
@@ -476,7 +495,7 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, MachineFunction &MF,
     if (InstrCount == MaxDuplicateCount) return false;
     // Remember if we saw a call.
     if (I->getDesc().isCall()) HasCall = true;
-    if (I->getOpcode() != TargetInstrInfo::PHI)
+    if (!I->isPHI())
       InstrCount += 1;
   }
   // Heuristically, don't tail-duplicate calls if it would expand code size,
@@ -528,7 +547,7 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, MachineFunction &MF,
     while (I != TailBB->end()) {
       MachineInstr *MI = &*I;
       ++I;
-      if (MI->getOpcode() == TargetInstrInfo::PHI) {
+      if (MI->isPHI()) {
         // Replace the uses of the def of the PHI with the register coming
         // from PredBB.
         ProcessPHI(MI, TailBB, PredBB, LocalVRMap, CopyInfos);
@@ -580,7 +599,7 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB, MachineFunction &MF,
       SmallVector<std::pair<unsigned,unsigned>, 4> CopyInfos;
       MachineBasicBlock::iterator I = TailBB->begin();
       // Process PHI instructions first.
-      while (I != TailBB->end() && I->getOpcode() == TargetInstrInfo::PHI) {
+      while (I != TailBB->end() && I->isPHI()) {
         // Replace the uses of the def of the PHI with the register coming
         // from PredBB.
         MachineInstr *MI = &*I++;