Don't use PassInfo* as a type identifier for passes. Instead, use the address of...
[oota-llvm.git] / lib / CodeGen / PreAllocSplitting.cpp
index e23024c085a3d6172a9d40f9a044f6db085bc3eb..82df6c2379312eb95f274ce3a58922c96979fbb0 100644 (file)
@@ -16,6 +16,7 @@
 
 #define DEBUG_TYPE "pre-alloc-split"
 #include "VirtRegMap.h"
+#include "llvm/CodeGen/CalcSpillWeights.h"
 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
 #include "llvm/CodeGen/LiveStackAnalysis.h"
 #include "llvm/CodeGen/MachineDominators.h"
@@ -91,7 +92,7 @@ namespace {
   public:
     static char ID;
     PreAllocSplitting()
-      : MachineFunctionPass(&ID) {}
+      : MachineFunctionPass(ID) {}
 
     virtual bool runOnMachineFunction(MachineFunction &MF);
 
@@ -104,6 +105,7 @@ namespace {
       AU.addRequired<LiveStacks>();
       AU.addPreserved<LiveStacks>();
       AU.addPreserved<RegisterCoalescer>();
+      AU.addPreserved<CalculateSpillWeights>();
       if (StrongPHIElim)
         AU.addPreservedID(StrongPHIEliminationID);
       else
@@ -133,17 +135,14 @@ namespace {
 
 
   private:
-    MachineBasicBlock::iterator
-      findNextEmptySlot(MachineBasicBlock*, MachineInstr*,
-                        SlotIndex&);
 
     MachineBasicBlock::iterator
       findSpillPoint(MachineBasicBlock*, MachineInstr*, MachineInstr*,
-                     SmallPtrSet<MachineInstr*, 4>&, SlotIndex&);
+                     SmallPtrSet<MachineInstr*, 4>&);
 
     MachineBasicBlock::iterator
       findRestorePoint(MachineBasicBlock*, MachineInstr*, SlotIndex,
-                     SmallPtrSet<MachineInstr*, 4>&, SlotIndex&);
+                     SmallPtrSet<MachineInstr*, 4>&);
 
     int CreateSpillStackSlot(unsigned, const TargetRegisterClass *);
 
@@ -163,7 +162,6 @@ namespace {
     bool Rematerialize(unsigned vreg, VNInfo* ValNo,
                        MachineInstr* DefMI,
                        MachineBasicBlock::iterator RestorePt,
-                       SlotIndex RestoreIdx,
                        SmallPtrSet<MachineInstr*, 4>& RefsInMBB);
     MachineInstr* FoldSpill(unsigned vreg, const TargetRegisterClass* RC,
                             MachineInstr* DefMI,
@@ -208,25 +206,7 @@ char PreAllocSplitting::ID = 0;
 static RegisterPass<PreAllocSplitting>
 X("pre-alloc-splitting", "Pre-Register Allocation Live Interval Splitting");
 
-const PassInfo *const llvm::PreAllocSplittingID = &X;
-
-
-/// findNextEmptySlot - Find a gap after the given machine instruction in the
-/// instruction index map. If there isn't one, return end().
-MachineBasicBlock::iterator
-PreAllocSplitting::findNextEmptySlot(MachineBasicBlock *MBB, MachineInstr *MI,
-                                     SlotIndex &SpotIndex) {
-  MachineBasicBlock::iterator MII = MI;
-  if (++MII != MBB->end()) {
-    SlotIndex Index =
-      LIs->findGapBeforeInstr(LIs->getInstructionIndex(MII));
-    if (Index != SlotIndex()) {
-      SpotIndex = Index;
-      return MII;
-    }
-  }
-  return MBB->end();
-}
+char &llvm::PreAllocSplittingID = PreAllocSplitting::ID;
 
 /// findSpillPoint - Find a gap as far away from the given MI that's suitable
 /// for spilling the current live interval. The index must be before any
@@ -235,8 +215,7 @@ PreAllocSplitting::findNextEmptySlot(MachineBasicBlock *MBB, MachineInstr *MI,
 MachineBasicBlock::iterator
 PreAllocSplitting::findSpillPoint(MachineBasicBlock *MBB, MachineInstr *MI,
                                   MachineInstr *DefMI,
-                                  SmallPtrSet<MachineInstr*, 4> &RefsInMBB,
-                                  SlotIndex &SpillIndex) {
+                                  SmallPtrSet<MachineInstr*, 4> &RefsInMBB) {
   MachineBasicBlock::iterator Pt = MBB->begin();
 
   MachineBasicBlock::iterator MII = MI;
@@ -249,8 +228,6 @@ PreAllocSplitting::findSpillPoint(MachineBasicBlock *MBB, MachineInstr *MI,
   if (MII == EndPt || RefsInMBB.count(MII)) return Pt;
     
   while (MII != EndPt && !RefsInMBB.count(MII)) {
-    SlotIndex Index = LIs->getInstructionIndex(MII);
-    
     // We can't insert the spill between the barrier (a call), and its
     // corresponding call frame setup.
     if (MII->getOpcode() == TRI->getCallFrameDestroyOpcode()) {
@@ -261,9 +238,8 @@ PreAllocSplitting::findSpillPoint(MachineBasicBlock *MBB, MachineInstr *MI,
         }
       }
       continue;
-    } else if (LIs->hasGapBeforeInstr(Index)) {
+    } else {
       Pt = MII;
-      SpillIndex = LIs->findGapBeforeInstr(Index, true);
     }
     
     if (RefsInMBB.count(MII))
@@ -283,8 +259,7 @@ PreAllocSplitting::findSpillPoint(MachineBasicBlock *MBB, MachineInstr *MI,
 MachineBasicBlock::iterator
 PreAllocSplitting::findRestorePoint(MachineBasicBlock *MBB, MachineInstr *MI,
                                     SlotIndex LastIdx,
-                                    SmallPtrSet<MachineInstr*, 4> &RefsInMBB,
-                                    SlotIndex &RestoreIndex) {
+                                    SmallPtrSet<MachineInstr*, 4> &RefsInMBB) {
   // FIXME: Allow spill to be inserted to the beginning of the mbb. Update mbb
   // begin index accordingly.
   MachineBasicBlock::iterator Pt = MBB->end();
@@ -308,7 +283,6 @@ PreAllocSplitting::findRestorePoint(MachineBasicBlock *MBB, MachineInstr *MI,
     SlotIndex Index = LIs->getInstructionIndex(MII);
     if (Index > LastIdx)
       break;
-    SlotIndex Gap = LIs->findGapBeforeInstr(Index);
       
     // We can't insert a restore between the barrier (a call) and its 
     // corresponding call frame teardown.
@@ -317,9 +291,8 @@ PreAllocSplitting::findRestorePoint(MachineBasicBlock *MBB, MachineInstr *MI,
         if (MII == EndPt || RefsInMBB.count(MII)) return Pt;
         ++MII;
       } while (MII->getOpcode() != TRI->getCallFrameDestroyOpcode());
-    } else if (Gap != SlotIndex()) {
+    } else {
       Pt = MII;
-      RestoreIndex = Gap;
     }
     
     if (RefsInMBB.count(MII))
@@ -341,7 +314,7 @@ int PreAllocSplitting::CreateSpillStackSlot(unsigned Reg,
   if (I != IntervalSSMap.end()) {
     SS = I->second;
   } else {
-    SS = MFI->CreateStackObject(RC->getSize(), RC->getAlignment());
+    SS = MFI->CreateSpillStackObject(RC->getSize(), RC->getAlignment());
     IntervalSSMap[Reg] = SS;
   }
 
@@ -405,7 +378,7 @@ PreAllocSplitting::UpdateSpillSlotInterval(VNInfo *ValNo, SlotIndex SpillIndex,
 
   SmallPtrSet<MachineBasicBlock*, 4> Processed;
   SlotIndex EndIdx = LIs->getMBBEndIdx(MBB);
-  LiveRange SLR(SpillIndex, EndIdx.getNextSlot(), CurrSValNo);
+  LiveRange SLR(SpillIndex, EndIdx, CurrSValNo);
   CurrSLI->addRange(SLR);
   Processed.insert(MBB);
 
@@ -502,44 +475,32 @@ PreAllocSplitting::PerformPHIConstruction(MachineBasicBlock::iterator UseI,
     SlotIndex EndIndex = LIs->getMBBEndIdx(MBB);
     
     RetVNI = NewVNs[Walker];
-    LI->addRange(LiveRange(DefIndex, EndIndex.getNextSlot(), RetVNI));
+    LI->addRange(LiveRange(DefIndex, EndIndex, RetVNI));
   } else if (!ContainsDefs && ContainsUses) {
     SmallPtrSet<MachineInstr*, 2>& BlockUses = Uses[MBB];
     
     // Search for the use in this block that precedes the instruction we care 
     // about, going to the fallback case if we don't find it.    
-    if (UseI == MBB->begin())
-      return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
-                                            Uses, NewVNs, LiveOut, Phis,
-                                            IsTopLevel, IsIntraBlock);
-    
     MachineBasicBlock::iterator Walker = UseI;
-    --Walker;
     bool found = false;
     while (Walker != MBB->begin()) {
+      --Walker;
       if (BlockUses.count(Walker)) {
         found = true;
         break;
       }
-      --Walker;
-    }
-        
-    // Must check begin() too.
-    if (!found) {
-      if (BlockUses.count(Walker))
-        found = true;
-      else
-        return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
-                                              Uses, NewVNs, LiveOut, Phis,
-                                              IsTopLevel, IsIntraBlock);
     }
 
+    if (!found)
+      return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
+                                            Uses, NewVNs, LiveOut, Phis,
+                                            IsTopLevel, IsIntraBlock);
+
     SlotIndex UseIndex = LIs->getInstructionIndex(Walker);
     UseIndex = UseIndex.getUseIndex();
     SlotIndex EndIndex;
     if (IsIntraBlock) {
-      EndIndex = LIs->getInstructionIndex(UseI);
-      EndIndex = EndIndex.getUseIndex();
+      EndIndex = LIs->getInstructionIndex(UseI).getDefIndex();
     } else
       EndIndex = LIs->getMBBEndIdx(MBB);
 
@@ -548,12 +509,9 @@ PreAllocSplitting::PerformPHIConstruction(MachineBasicBlock::iterator UseI,
     RetVNI = PerformPHIConstruction(Walker, MBB, LI, Visited, Defs, Uses,
                                     NewVNs, LiveOut, Phis, false, true);
     
-    LI->addRange(LiveRange(UseIndex, EndIndex.getNextSlot(), RetVNI));
+    LI->addRange(LiveRange(UseIndex, EndIndex, RetVNI));
     
     // FIXME: Need to set kills properly for inter-block stuff.
-    if (RetVNI->isKill(UseIndex)) RetVNI->removeKill(UseIndex);
-    if (IsIntraBlock)
-      RetVNI->addKill(EndIndex);
   } else if (ContainsDefs && ContainsUses) {
     SmallPtrSet<MachineInstr*, 2>& BlockDefs = Defs[MBB];
     SmallPtrSet<MachineInstr*, 2>& BlockUses = Uses[MBB];
@@ -561,17 +519,11 @@ PreAllocSplitting::PerformPHIConstruction(MachineBasicBlock::iterator UseI,
     // This case is basically a merging of the two preceding case, with the
     // special note that checking for defs must take precedence over checking
     // for uses, because of two-address instructions.
-    
-    if (UseI == MBB->begin())
-      return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs, Uses,
-                                            NewVNs, LiveOut, Phis,
-                                            IsTopLevel, IsIntraBlock);
-    
     MachineBasicBlock::iterator Walker = UseI;
-    --Walker;
     bool foundDef = false;
     bool foundUse = false;
     while (Walker != MBB->begin()) {
+      --Walker;
       if (BlockDefs.count(Walker)) {
         foundDef = true;
         break;
@@ -579,27 +531,18 @@ PreAllocSplitting::PerformPHIConstruction(MachineBasicBlock::iterator UseI,
         foundUse = true;
         break;
       }
-      --Walker;
-    }
-        
-    // Must check begin() too.
-    if (!foundDef && !foundUse) {
-      if (BlockDefs.count(Walker))
-        foundDef = true;
-      else if (BlockUses.count(Walker))
-        foundUse = true;
-      else
-        return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
-                                              Uses, NewVNs, LiveOut, Phis,
-                                              IsTopLevel, IsIntraBlock);
     }
 
+    if (!foundDef && !foundUse)
+      return PerformPHIConstructionFallBack(UseI, MBB, LI, Visited, Defs,
+                                            Uses, NewVNs, LiveOut, Phis,
+                                            IsTopLevel, IsIntraBlock);
+
     SlotIndex StartIndex = LIs->getInstructionIndex(Walker);
     StartIndex = foundDef ? StartIndex.getDefIndex() : StartIndex.getUseIndex();
     SlotIndex EndIndex;
     if (IsIntraBlock) {
-      EndIndex = LIs->getInstructionIndex(UseI);
-      EndIndex = EndIndex.getUseIndex();
+      EndIndex = LIs->getInstructionIndex(UseI).getDefIndex();
     } else
       EndIndex = LIs->getMBBEndIdx(MBB);
 
@@ -609,13 +552,7 @@ PreAllocSplitting::PerformPHIConstruction(MachineBasicBlock::iterator UseI,
       RetVNI = PerformPHIConstruction(Walker, MBB, LI, Visited, Defs, Uses,
                                       NewVNs, LiveOut, Phis, false, true);
 
-    LI->addRange(LiveRange(StartIndex, EndIndex.getNextSlot(), RetVNI));
-    
-    if (foundUse && RetVNI->isKill(StartIndex))
-      RetVNI->removeKill(StartIndex);
-    if (IsIntraBlock) {
-      RetVNI->addKill(EndIndex);
-    }
+    LI->addRange(LiveRange(StartIndex, EndIndex, RetVNI));
   }
   
   // Memoize results so we don't have to recompute them.
@@ -690,21 +627,15 @@ PreAllocSplitting::PerformPHIConstructionFallBack(MachineBasicBlock::iterator Us
     for (DenseMap<MachineBasicBlock*, VNInfo*>::iterator I =
            IncomingVNs.begin(), E = IncomingVNs.end(); I != E; ++I) {
       I->second->setHasPHIKill(true);
-      SlotIndex KillIndex = LIs->getMBBEndIdx(I->first);
-      if (!I->second->isKill(KillIndex))
-        I->second->addKill(KillIndex);
     }
   }
       
   SlotIndex EndIndex;
   if (IsIntraBlock) {
-    EndIndex = LIs->getInstructionIndex(UseI);
-    EndIndex = EndIndex.getUseIndex();
+    EndIndex = LIs->getInstructionIndex(UseI).getDefIndex();
   } else
     EndIndex = LIs->getMBBEndIdx(MBB);
-  LI->addRange(LiveRange(StartIndex, EndIndex.getNextSlot(), RetVNI));
-  if (IsIntraBlock)
-    RetVNI->addKill(EndIndex);
+  LI->addRange(LiveRange(StartIndex, EndIndex, RetVNI));
 
   // Memoize results so we don't have to recompute them.
   if (!IsIntraBlock)
@@ -720,7 +651,7 @@ PreAllocSplitting::PerformPHIConstructionFallBack(MachineBasicBlock::iterator Us
 
 /// ReconstructLiveInterval - Recompute a live interval from scratch.
 void PreAllocSplitting::ReconstructLiveInterval(LiveInterval* LI) {
-  BumpPtrAllocator& Alloc = LIs->getVNInfoAllocator();
+  VNInfo::Allocator& Alloc = LIs->getVNInfoAllocator();
   
   // Clear the old ranges and valnos;
   LI->clear();
@@ -741,16 +672,13 @@ void PreAllocSplitting::ReconstructLiveInterval(LiveInterval* LI) {
     SlotIndex DefIdx = LIs->getInstructionIndex(&*DI);
     DefIdx = DefIdx.getDefIndex();
     
-    assert(DI->getOpcode() != TargetInstrInfo::PHI &&
-           "Following NewVN isPHIDef flag incorrect. Fix me!");
+    assert(!DI->isPHI() && "PHI instr in code during pre-alloc splitting.");
     VNInfo* NewVN = LI->getNextValue(DefIdx, 0, true, Alloc);
     
     // If the def is a move, set the copy field.
-    unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
-    if (TII->isMoveInstr(*DI, SrcReg, DstReg, SrcSubIdx, DstSubIdx))
-      if (DstReg == LI->reg)
-        NewVN->setCopy(&*DI);
-    
+    if (DI->isCopyLike() && DI->getOperand(0).getReg() == LI->reg)
+      NewVN->setCopy(&*DI);
+
     NewVNs[&*DI] = NewVN;
   }
   
@@ -781,25 +709,6 @@ void PreAllocSplitting::ReconstructLiveInterval(LiveInterval* LI) {
     
     VNInfo* DeadVN = NewVNs[&*DI];
     LI->addRange(LiveRange(DefIdx, DefIdx.getNextSlot(), DeadVN));
-    DeadVN->addKill(DefIdx);
-  }
-
-  // Update kill markers.
-  for (LiveInterval::vni_iterator VI = LI->vni_begin(), VE = LI->vni_end();
-       VI != VE; ++VI) {
-    VNInfo* VNI = *VI;
-    for (unsigned i = 0, e = VNI->kills.size(); i != e; ++i) {
-      SlotIndex KillIdx = VNI->kills[i];
-      if (KillIdx.isPHI())
-        continue;
-      MachineInstr *KillMI = LIs->getInstructionFromIndex(KillIdx);
-      if (KillMI) {
-        MachineOperand *KillMO = KillMI->findRegisterUseOperand(CurrLI->reg);
-        if (KillMO)
-          // It could be a dead def.
-          KillMO->setIsKill();
-      }
-    }
   }
 }
 
@@ -829,19 +738,14 @@ void PreAllocSplitting::RenumberValno(VNInfo* VN) {
     VNsToCopy.push_back(OldVN);
     
     // Locate two-address redefinitions
-    for (VNInfo::KillSet::iterator KI = OldVN->kills.begin(),
-         KE = OldVN->kills.end(); KI != KE; ++KI) {
-      assert(!KI->isPHI() &&
-             "VN previously reported having no PHI kills.");
-      MachineInstr* MI = LIs->getInstructionFromIndex(*KI);
-      unsigned DefIdx = MI->findRegisterDefOperandIdx(CurrLI->reg);
-      if (DefIdx == ~0U) continue;
-      if (MI->isRegTiedToUseOperand(DefIdx)) {
-        VNInfo* NextVN =
-          CurrLI->findDefinedVNInfoForRegInt(KI->getDefIndex());
-        if (NextVN == OldVN) continue;
+    for (MachineRegisterInfo::def_iterator DI = MRI->def_begin(CurrLI->reg),
+         DE = MRI->def_end(); DI != DE; ++DI) {
+      if (!DI->isRegTiedToUseOperand(DI.getOperandNo())) continue;
+      SlotIndex DefIdx = LIs->getInstructionIndex(&*DI).getDefIndex();
+      VNInfo* NextVN = CurrLI->findDefinedVNInfoForRegInt(DefIdx);
+      if (std::find(VNsToCopy.begin(), VNsToCopy.end(), NextVN) !=
+          VNsToCopy.end())
         Stack.push_back(NextVN);
-      }
     }
   }
   
@@ -892,31 +796,28 @@ void PreAllocSplitting::RenumberValno(VNInfo* VN) {
   if (IntervalSSMap.count(CurrLI->reg))
     IntervalSSMap[NewVReg] = IntervalSSMap[CurrLI->reg];
   
-  NumRenumbers++;
+  ++NumRenumbers;
 }
 
 bool PreAllocSplitting::Rematerialize(unsigned VReg, VNInfo* ValNo,
                                       MachineInstr* DefMI,
                                       MachineBasicBlock::iterator RestorePt,
-                                      SlotIndex RestoreIdx,
                                     SmallPtrSet<MachineInstr*, 4>& RefsInMBB) {
   MachineBasicBlock& MBB = *RestorePt->getParent();
   
   MachineBasicBlock::iterator KillPt = BarrierMBB->end();
-  SlotIndex KillIdx;
   if (!ValNo->isDefAccurate() || DefMI->getParent() == BarrierMBB)
-    KillPt = findSpillPoint(BarrierMBB, Barrier, NULL, RefsInMBB, KillIdx);
+    KillPt = findSpillPoint(BarrierMBB, Barrier, NULL, RefsInMBB);
   else
-    KillPt = findNextEmptySlot(DefMI->getParent(), DefMI, KillIdx);
+    KillPt = llvm::next(MachineBasicBlock::iterator(DefMI));
   
   if (KillPt == DefMI->getParent()->end())
     return false;
   
-  TII->reMaterialize(MBB, RestorePt, VReg, 0, DefMI);
-  LIs->InsertMachineInstrInMaps(prior(RestorePt), RestoreIdx);
+  TII->reMaterialize(MBB, RestorePt, VReg, 0, DefMI, *TRI);
+  SlotIndex RematIdx = LIs->InsertMachineInstrInMaps(prior(RestorePt));
   
   ReconstructLiveInterval(CurrLI);
-  SlotIndex RematIdx = LIs->getInstructionIndex(prior(RestorePt));
   RematIdx = RematIdx.getDefIndex();
   RenumberValno(CurrLI->findDefinedVNInfoForRegInt(RematIdx));
   
@@ -932,8 +833,6 @@ MachineInstr* PreAllocSplitting::FoldSpill(unsigned vreg,
                                            MachineBasicBlock* MBB,
                                            int& SS,
                                     SmallPtrSet<MachineInstr*, 4>& RefsInMBB) {
-  MachineBasicBlock::iterator Pt = MBB->begin();
-
   // Go top down if RefsInMBB is empty.
   if (RefsInMBB.empty())
     return 0;
@@ -943,7 +842,7 @@ MachineInstr* PreAllocSplitting::FoldSpill(unsigned vreg,
          !RefsInMBB.count(FoldPt))
     --FoldPt;
   
-  int OpIdx = FoldPt->findRegisterDefOperandIdx(vreg, false);
+  int OpIdx = FoldPt->findRegisterDefOperandIdx(vreg);
   if (OpIdx == -1)
     return 0;
   
@@ -957,15 +856,14 @@ MachineInstr* PreAllocSplitting::FoldSpill(unsigned vreg,
   if (I != IntervalSSMap.end()) {
     SS = I->second;
   } else {
-    SS = MFI->CreateStackObject(RC->getSize(), RC->getAlignment());
+    SS = MFI->CreateSpillStackObject(RC->getSize(), RC->getAlignment());
   }
   
-  MachineInstr* FMI = TII->foldMemoryOperand(*MBB->getParent(),
-                                             FoldPt, Ops, SS);
+  MachineInstr* FMI = TII->foldMemoryOperand(FoldPt, Ops, SS);
   
   if (FMI) {
     LIs->ReplaceMachineInstrInMaps(FoldPt, FMI);
-    FMI = MBB->insert(MBB->erase(FoldPt), FMI);
+    FoldPt->eraseFromParent();
     ++NumFolds;
     
     IntervalSSMap[vreg] = SS;
@@ -1041,12 +939,11 @@ MachineInstr* PreAllocSplitting::FoldRestore(unsigned vreg,
   if (!TII->canFoldMemoryOperand(FoldPt, Ops))
     return 0;
   
-  MachineInstr* FMI = TII->foldMemoryOperand(*MBB->getParent(),
-                                             FoldPt, Ops, SS);
+  MachineInstr* FMI = TII->foldMemoryOperand(FoldPt, Ops, SS);
   
   if (FMI) {
     LIs->ReplaceMachineInstrInMaps(FoldPt, FMI);
-    FMI = MBB->insert(MBB->erase(FoldPt), FMI);
+    FoldPt->eraseFromParent();
     ++NumRestoreFolds;
   }
   
@@ -1057,7 +954,7 @@ MachineInstr* PreAllocSplitting::FoldRestore(unsigned vreg,
 /// so it would not cross the barrier that's being processed. Shrink wrap
 /// (minimize) the live interval to the last uses.
 bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
-  DEBUG(errs() << "Pre-alloc splitting " << LI->reg << " for " << *Barrier
+  DEBUG(dbgs() << "Pre-alloc splitting " << LI->reg << " for " << *Barrier
                << "  result: ");
 
   CurrLI = LI;
@@ -1074,7 +971,7 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
 
   // If this would create a new join point, do not split.
   if (DefMI && createsNewJoin(LR, DefMI->getParent(), Barrier->getParent())) {
-    DEBUG(errs() << "FAILED (would create a new join point).\n");
+    DEBUG(dbgs() << "FAILED (would create a new join point).\n");
     return false;
   }
 
@@ -1088,18 +985,16 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
   }
 
   // Find a point to restore the value after the barrier.
-  SlotIndex RestoreIndex;
   MachineBasicBlock::iterator RestorePt =
-    findRestorePoint(BarrierMBB, Barrier, LR->end, RefsInMBB, RestoreIndex);
+    findRestorePoint(BarrierMBB, Barrier, LR->end, RefsInMBB);
   if (RestorePt == BarrierMBB->end()) {
-    DEBUG(errs() << "FAILED (could not find a suitable restore point).\n");
+    DEBUG(dbgs() << "FAILED (could not find a suitable restore point).\n");
     return false;
   }
 
   if (DefMI && LIs->isReMaterializable(*LI, ValNo, DefMI))
-    if (Rematerialize(LI->reg, ValNo, DefMI, RestorePt,
-                      RestoreIndex, RefsInMBB)) {
-      DEBUG(errs() << "success (remat).\n");
+    if (Rematerialize(LI->reg, ValNo, DefMI, RestorePt, RefsInMBB)) {
+      DEBUG(dbgs() << "success (remat).\n");
       return true;
     }
 
@@ -1116,24 +1011,25 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
       SpillIndex = LIs->getInstructionIndex(SpillMI);
     } else {
       MachineBasicBlock::iterator SpillPt = 
-        findSpillPoint(BarrierMBB, Barrier, NULL, RefsInMBB, SpillIndex);
+        findSpillPoint(BarrierMBB, Barrier, NULL, RefsInMBB);
       if (SpillPt == BarrierMBB->begin()) {
-        DEBUG(errs() << "FAILED (could not find a suitable spill point).\n");
+        DEBUG(dbgs() << "FAILED (could not find a suitable spill point).\n");
         return false; // No gap to insert spill.
       }
       // Add spill.
     
       SS = CreateSpillStackSlot(CurrLI->reg, RC);
-      TII->storeRegToStackSlot(*BarrierMBB, SpillPt, CurrLI->reg, true, SS, RC);
+      TII->storeRegToStackSlot(*BarrierMBB, SpillPt, CurrLI->reg, true, SS, RC,
+                               TRI);
       SpillMI = prior(SpillPt);
-      LIs->InsertMachineInstrInMaps(SpillMI, SpillIndex);
+      SpillIndex = LIs->InsertMachineInstrInMaps(SpillMI);
     }
   } else if (!IsAvailableInStack(DefMBB, CurrLI->reg, ValNo->def,
-                                 RestoreIndex, SpillIndex, SS)) {
+                                 LIs->getZeroIndex(), SpillIndex, SS)) {
     // If it's already split, just restore the value. There is no need to spill
     // the def again.
     if (!DefMI) {
-      DEBUG(errs() << "FAILED (def is dead).\n");
+      DEBUG(dbgs() << "FAILED (def is dead).\n");
       return false; // Def is dead. Do nothing.
     }
     
@@ -1146,23 +1042,24 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
       if (DefMBB == BarrierMBB) {
         // Add spill after the def and the last use before the barrier.
         SpillPt = findSpillPoint(BarrierMBB, Barrier, DefMI,
-                                 RefsInMBB, SpillIndex);
+                                 RefsInMBB);
         if (SpillPt == DefMBB->begin()) {
-          DEBUG(errs() << "FAILED (could not find a suitable spill point).\n");
+          DEBUG(dbgs() << "FAILED (could not find a suitable spill point).\n");
           return false; // No gap to insert spill.
         }
       } else {
-        SpillPt = findNextEmptySlot(DefMBB, DefMI, SpillIndex);
+        SpillPt = llvm::next(MachineBasicBlock::iterator(DefMI));
         if (SpillPt == DefMBB->end()) {
-          DEBUG(errs() << "FAILED (could not find a suitable spill point).\n");
+          DEBUG(dbgs() << "FAILED (could not find a suitable spill point).\n");
           return false; // No gap to insert spill.
         }
       }
       // Add spill. 
       SS = CreateSpillStackSlot(CurrLI->reg, RC);
-      TII->storeRegToStackSlot(*DefMBB, SpillPt, CurrLI->reg, false, SS, RC);
+      TII->storeRegToStackSlot(*DefMBB, SpillPt, CurrLI->reg, false, SS, RC,
+                               TRI);
       SpillMI = prior(SpillPt);
-      LIs->InsertMachineInstrInMaps(SpillMI, SpillIndex);
+      SpillIndex = LIs->InsertMachineInstrInMaps(SpillMI);
     }
   }
 
@@ -1172,15 +1069,16 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
 
   // Add restore.
   bool FoldedRestore = false;
+  SlotIndex RestoreIndex;
   if (MachineInstr* LMI = FoldRestore(CurrLI->reg, RC, Barrier,
                                       BarrierMBB, SS, RefsInMBB)) {
     RestorePt = LMI;
     RestoreIndex = LIs->getInstructionIndex(RestorePt);
     FoldedRestore = true;
   } else {
-    TII->loadRegFromStackSlot(*BarrierMBB, RestorePt, CurrLI->reg, SS, RC);
+    TII->loadRegFromStackSlot(*BarrierMBB, RestorePt, CurrLI->reg, SS, RC, TRI);
     MachineInstr *LoadMI = prior(RestorePt);
-    LIs->InsertMachineInstrInMaps(LoadMI, RestoreIndex);
+    RestoreIndex = LIs->InsertMachineInstrInMaps(LoadMI);
   }
 
   // Update spill stack slot live interval.
@@ -1196,7 +1094,7 @@ bool PreAllocSplitting::SplitRegLiveInterval(LiveInterval *LI) {
   }
   
   ++NumSplits;
-  DEBUG(errs() << "success.\n");
+  DEBUG(dbgs() << "success.\n");
   return true;
 }
 
@@ -1214,7 +1112,7 @@ PreAllocSplitting::SplitRegLiveIntervals(const TargetRegisterClass **RCs,
     // codegen is not modelling. Ignore these barriers for now.
     if (!TII->isSafeToMoveRegClassDefs(*RC))
       continue;
-    std::vector<unsigned> &VRs = MRI->getRegClassVirtRegs(*RC);
+    const std::vector<unsigned> &VRs = MRI->getRegClassVirtRegs(*RC);
     for (unsigned i = 0, e = VRs.size(); i != e; ++i) {
       unsigned Reg = VRs[i];
       if (!LIs->hasInterval(Reg))
@@ -1252,7 +1150,7 @@ unsigned PreAllocSplitting::getNumberOfNonSpills(
     int StoreFrameIndex;
     unsigned StoreVReg = TII->isStoreToStackSlot(*UI, StoreFrameIndex);
     if (StoreVReg != Reg || StoreFrameIndex != FrameIndex)
-      NonSpills++;
+      ++NonSpills;
     
     int DefIdx = (*UI)->findRegisterDefOperandIdx(Reg);
     if (DefIdx != -1 && (*UI)->isRegTiedToUseOperand(DefIdx))
@@ -1315,7 +1213,7 @@ bool PreAllocSplitting::removeDeadSpills(SmallPtrSet<LiveInterval*, 8>& split) {
         (*LI)->removeValNo(CurrVN);
         DefMI->eraseFromParent();
         VNUseCount.erase(CurrVN);
-        NumDeadSpills++;
+        ++NumDeadSpills;
         changed = true;
         continue;
       }
@@ -1351,9 +1249,7 @@ bool PreAllocSplitting::removeDeadSpills(SmallPtrSet<LiveInterval*, 8>& split) {
         Ops.push_back(OpIdx);
         if (!TII->canFoldMemoryOperand(use, Ops)) continue;
 
-        MachineInstr* NewMI =
-                          TII->foldMemoryOperand(*use->getParent()->getParent(),  
-                                                 use, Ops, FrameIndex);
+        MachineInstr* NewMI = TII->foldMemoryOperand(use, Ops, FrameIndex);
 
         if (!NewMI) continue;
 
@@ -1363,10 +1259,9 @@ bool PreAllocSplitting::removeDeadSpills(SmallPtrSet<LiveInterval*, 8>& split) {
         (*LI)->removeValNo(CurrVN);
 
         DefMI->eraseFromParent();
-        MachineBasicBlock* MBB = use->getParent();
-        NewMI = MBB->insert(MBB->erase(use), NewMI);
+        use->eraseFromParent();
         VNUseCount[CurrVN].erase(use);
-        
+
         // Remove deleted instructions.  Note that we need to remove them from 
         // the VNInfo->use map as well, just to be safe.
         for (SmallPtrSet<MachineInstr*, 4>::iterator II = 
@@ -1388,7 +1283,7 @@ bool PreAllocSplitting::removeDeadSpills(SmallPtrSet<LiveInterval*, 8>& split) {
           if (VI->second.erase(use))
             VI->second.insert(NewMI);
 
-        NumDeadSpills++;
+        ++NumDeadSpills;
         changed = true;
         continue;
       }
@@ -1400,7 +1295,7 @@ bool PreAllocSplitting::removeDeadSpills(SmallPtrSet<LiveInterval*, 8>& split) {
       // Otherwise, this is a load-store case, so DCE them.
       for (SmallPtrSet<MachineInstr*, 4>::iterator UI = 
            VNUseCount[CurrVN].begin(), UE = VNUseCount[CurrVN].end();
-           UI != UI; ++UI) {
+           UI != UE; ++UI) {
         LIs->RemoveMachineInstrFromMaps(*UI);
         (*UI)->eraseFromParent();
       }
@@ -1410,7 +1305,7 @@ bool PreAllocSplitting::removeDeadSpills(SmallPtrSet<LiveInterval*, 8>& split) {
       LIs->RemoveMachineInstrFromMaps(DefMI);
       (*LI)->removeValNo(CurrVN);
       DefMI->eraseFromParent();
-      NumDeadSpills++;
+      ++NumDeadSpills;
       changed = true;
     }
   }