diff --git a/lib/CodeGen/InlineSpiller.cpp b/lib/CodeGen/InlineSpiller.cpp
index 076d230..12adcaa 100644
--- a/lib/CodeGen/InlineSpiller.cpp
+++ b/lib/CodeGen/InlineSpiller.cpp
@@ -282,13 +282,12 @@
       FoldOps.push_back(Idx);
   }
 
-  MachineInstr *FoldMI = tii_.foldMemoryOperand(mf_, MI, FoldOps, stackSlot_);
+  MachineInstr *FoldMI = tii_.foldMemoryOperand(MI, FoldOps, stackSlot_);
   if (!FoldMI)
     return false;
-  MachineBasicBlock &MBB = *MI->getParent();
   lis_.ReplaceMachineInstrInMaps(MI, FoldMI);
   vrm_.addSpillSlotUse(stackSlot_, FoldMI);
-  MBB.insert(MBB.erase(MI), FoldMI);
+  MI->eraseFromParent();
   DEBUG(dbgs() << "\tfolded: " << *FoldMI);
   return true;
 }
diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 74ca497..742dc64 100644
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -946,22 +946,22 @@
   if (DefMI && (MRInfo & VirtRegMap::isMod))
     return false;
 
-  MachineInstr *fmi = isSS ? tii_->foldMemoryOperand(*mf_, MI, FoldOps, Slot)
-                           : tii_->foldMemoryOperand(*mf_, MI, FoldOps, DefMI);
+  MachineInstr *fmi = isSS ? tii_->foldMemoryOperand(MI, FoldOps, Slot)
+                           : tii_->foldMemoryOperand(MI, FoldOps, DefMI);
   if (fmi) {
     // Remember this instruction uses the spill slot.
     if (isSS) vrm.addSpillSlotUse(Slot, fmi);
 
     // Attempt to fold the memory reference into the instruction. If
     // we can do this, we don't need to insert spill code.
-    MachineBasicBlock &MBB = *MI->getParent();
     if (isSS && !mf_->getFrameInfo()->isImmutableObjectIndex(Slot))
       vrm.virtFolded(Reg, MI, fmi, (VirtRegMap::ModRef)MRInfo);
     vrm.transferSpillPts(MI, fmi);
     vrm.transferRestorePts(MI, fmi);
     vrm.transferEmergencySpills(MI, fmi);
     ReplaceMachineInstrInMaps(MI, fmi);
-    MI = MBB.insert(MBB.erase(MI), fmi);
+    MI->eraseFromParent();
+    MI = fmi;
     ++numFolds;
     return true;
   }
diff --git a/lib/CodeGen/PreAllocSplitting.cpp b/lib/CodeGen/PreAllocSplitting.cpp
index fbe9918..fb2f909 100644
--- a/lib/CodeGen/PreAllocSplitting.cpp
+++ b/lib/CodeGen/PreAllocSplitting.cpp
@@ -863,12 +863,11 @@
     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;
@@ -944,12 +943,11 @@
   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;
   }
   
@@ -1255,9 +1253,7 @@
         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;
 
@@ -1267,10 +1263,9 @@
         (*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 = 
diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp
index ff8d0ed..cc6431d 100644
--- a/lib/CodeGen/TargetInstrInfoImpl.cpp
+++ b/lib/CodeGen/TargetInstrInfoImpl.cpp
@@ -197,8 +197,7 @@
 /// removing the old instruction and adding the new one in the instruction
 /// stream.
 MachineInstr*
-TargetInstrInfo::foldMemoryOperand(MachineFunction &MF,
-                                   MachineInstr* MI,
+TargetInstrInfo::foldMemoryOperand(MachineBasicBlock::iterator MI,
                                    const SmallVectorImpl<unsigned> &Ops,
                                    int FrameIndex) const {
   unsigned Flags = 0;
@@ -208,10 +207,15 @@
     else
       Flags |= MachineMemOperand::MOLoad;
 
+  MachineBasicBlock &MBB = *MI->getParent();
+  MachineFunction &MF = *MBB.getParent();
+
   // Ask the target to do the actual folding.
   MachineInstr *NewMI = foldMemoryOperandImpl(MF, MI, Ops, FrameIndex);
   if (!NewMI) return 0;
 
+  NewMI = MBB.insert(MI, NewMI);
+
   assert((!(Flags & MachineMemOperand::MOStore) ||
           NewMI->getDesc().mayStore()) &&
          "Folded a def to a non-store!");
@@ -234,8 +238,7 @@
 /// of any load and store from / to any address, not just from a specific
 /// stack slot.
 MachineInstr*
-TargetInstrInfo::foldMemoryOperand(MachineFunction &MF,
-                                   MachineInstr* MI,
+TargetInstrInfo::foldMemoryOperand(MachineBasicBlock::iterator MI,
                                    const SmallVectorImpl<unsigned> &Ops,
                                    MachineInstr* LoadMI) const {
   assert(LoadMI->getDesc().canFoldAsLoad() && "LoadMI isn't foldable!");
@@ -243,11 +246,15 @@
   for (unsigned i = 0, e = Ops.size(); i != e; ++i)
     assert(MI->getOperand(Ops[i]).isUse() && "Folding load into def!");
 #endif
+  MachineBasicBlock &MBB = *MI->getParent();
+  MachineFunction &MF = *MBB.getParent();
 
   // Ask the target to do the actual folding.
   MachineInstr *NewMI = foldMemoryOperandImpl(MF, MI, Ops, LoadMI);
   if (!NewMI) return 0;
 
+  NewMI = MBB.insert(MI, NewMI);
+
   // Copy the memoperands from the load to the folded instruction.
   NewMI->setMemRefs(LoadMI->memoperands_begin(),
                     LoadMI->memoperands_end());
diff --git a/lib/CodeGen/VirtRegRewriter.cpp b/lib/CodeGen/VirtRegRewriter.cpp
index d8f0249..7d48eac 100644
--- a/lib/CodeGen/VirtRegRewriter.cpp
+++ b/lib/CodeGen/VirtRegRewriter.cpp
@@ -1409,25 +1409,25 @@
     if (TII->unfoldMemoryOperand(MF, &MI, UnfoldVR, false, false, NewMIs)) {
       assert(NewMIs.size() == 1);
       MachineInstr *NewMI = NewMIs.back();
+      MBB->insert(MII, NewMI);
       NewMIs.clear();
       int Idx = NewMI->findRegisterUseOperandIdx(VirtReg, false);
       assert(Idx != -1);
       SmallVector<unsigned, 1> Ops;
       Ops.push_back(Idx);
-      MachineInstr *FoldedMI = TII->foldMemoryOperand(MF, NewMI, Ops, SS);
+      MachineInstr *FoldedMI = TII->foldMemoryOperand(NewMI, Ops, SS);
+      NewMI->eraseFromParent();
       if (FoldedMI) {
         VRM->addSpillSlotUse(SS, FoldedMI);
         if (!VRM->hasPhys(UnfoldVR))
           VRM->assignVirt2Phys(UnfoldVR, UnfoldPR);
         VRM->virtFolded(VirtReg, FoldedMI, VirtRegMap::isRef);
-        MII = MBB->insert(MII, FoldedMI);
+        MII = FoldedMI;
         InvalidateKills(MI, TRI, RegKills, KillOps);
         VRM->RemoveMachineInstrFromMaps(&MI);
         MBB->erase(&MI);
-        MF.DeleteMachineInstr(NewMI);
         return true;
       }
-      MF.DeleteMachineInstr(NewMI);
     }
   }
 
@@ -1479,7 +1479,6 @@
   if (MII == MBB->begin() || !MII->killsRegister(SrcReg))
     return false;
 
-  MachineFunction &MF = *MBB->getParent();
   MachineInstr &MI = *MII;
   MachineBasicBlock::iterator DefMII = prior(MII);
   MachineInstr *DefMI = DefMII;
@@ -1510,11 +1509,12 @@
     MachineInstr *CommutedMI = TII->commuteInstruction(DefMI, true);
     if (!CommutedMI)
       return false;
+    MBB->insert(MII, CommutedMI);
     SmallVector<unsigned, 1> Ops;
     Ops.push_back(NewDstIdx);
-    MachineInstr *FoldedMI = TII->foldMemoryOperand(MF, CommutedMI, Ops, SS);
+    MachineInstr *FoldedMI = TII->foldMemoryOperand(CommutedMI, Ops, SS);
     // Not needed since foldMemoryOperand returns new MI.
-    MF.DeleteMachineInstr(CommutedMI);
+    CommutedMI->eraseFromParent();
     if (!FoldedMI)
       return false;
 
@@ -1527,7 +1527,7 @@
     MachineInstr *StoreMI = MII;
     VRM->addSpillSlotUse(SS, StoreMI);
     VRM->virtFolded(VirtReg, StoreMI, VirtRegMap::isMod);
-    MII = MBB->insert(MII, FoldedMI);  // Update MII to backtrack.
+    MII = FoldedMI;  // Update MII to backtrack.
 
     // Delete all 3 old instructions.
     InvalidateKills(*ReloadMI, TRI, RegKills, KillOps);