Change MachineBasicBlock's vector of MachineInstr pointers into an

ilist of MachineInstr objects. This allows constant time removal and
insertion of MachineInstr instances from anywhere in each
MachineBasicBlock. It also allows for constant time splicing of
MachineInstrs into or out of MachineBasicBlocks.

llvm-svn: 11340

1 files changed, 13 insertions, 12 deletions

diff --git a/llvm/lib/CodeGen/PrologEpilogInserter.cpp b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
index 79406f95809..8f34cf48adb 100644
--- a/llvm/lib/CodeGen/PrologEpilogInserter.cpp
+++ b/llvm/lib/CodeGen/PrologEpilogInserter.cpp
@@ -105,17 +105,17 @@ void PEI::saveCallerSavedRegisters(MachineFunction &Fn) {
 
   for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB)
     for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); )
-      if ((*I)->getOpcode() == FrameSetupOpcode ||
-	  (*I)->getOpcode() == FrameDestroyOpcode) {
-	assert((*I)->getNumOperands() == 1 && "Call Frame Setup/Destroy Pseudo"
+      if (I->getOpcode() == FrameSetupOpcode ||
+	  I->getOpcode() == FrameDestroyOpcode) {
+	assert(I->getNumOperands() == 1 && "Call Frame Setup/Destroy Pseudo"
 	       " instructions should have a single immediate argument!");
-	unsigned Size = (*I)->getOperand(0).getImmedValue();
+	unsigned Size = I->getOperand(0).getImmedValue();
 	if (Size > MaxCallFrameSize) MaxCallFrameSize = Size;
 	HasCalls = true;
-	RegInfo->eliminateCallFramePseudoInstr(Fn, *BB, I);
+	RegInfo->eliminateCallFramePseudoInstr(Fn, *BB, I++);
       } else {
-	for (unsigned i = 0, e = (*I)->getNumOperands(); i != e; ++i) {
-	  MachineOperand &MO = (*I)->getOperand(i);
+	for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
+	  MachineOperand &MO = I->getOperand(i);
 	  if (MO.isRegister() && MO.isDef()) {
             assert(MRegisterInfo::isPhysicalRegister(MO.getReg()) &&
                    "Register allocation must be performed!");
@@ -174,8 +174,9 @@ void PEI::saveCallerSavedRegisters(MachineFunction &Fn) {
   const TargetInstrInfo &TII = Fn.getTarget().getInstrInfo();
   for (MachineFunction::iterator FI = Fn.begin(), E = Fn.end(); FI != E; ++FI) {
     // If last instruction is a return instruction, add an epilogue
-    if (!FI->empty() && TII.isReturn(FI->back()->getOpcode())) {
-      MBB = FI; I = MBB->end()-1;
+    if (!FI->empty() && TII.isReturn(FI->back().getOpcode())) {
+      MBB = FI;
+      I = MBB->end(); --I;
 
       for (unsigned i = 0, e = RegsToSave.size(); i != e; ++i) {
 	const TargetRegisterClass *RC = RegInfo->getRegClass(RegsToSave[i]);
@@ -235,7 +236,7 @@ void PEI::insertPrologEpilogCode(MachineFunction &Fn) {
   const TargetInstrInfo &TII = Fn.getTarget().getInstrInfo();
   for (MachineFunction::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) {
     // If last instruction is a return instruction, add an epilogue
-    if (!I->empty() && TII.isReturn(I->back()->getOpcode()))
+    if (!I->empty() && TII.isReturn(I->back().getOpcode()))
       Fn.getTarget().getRegisterInfo()->emitEpilogue(Fn, *I);
   }
 }
@@ -253,8 +254,8 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) {
 
   for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB)
     for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ++I)
-      for (unsigned i = 0, e = (*I)->getNumOperands(); i != e; ++i)
-	if ((*I)->getOperand(i).isFrameIndex()) {
+      for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
+	if (I->getOperand(i).isFrameIndex()) {
 	  // If this instruction has a FrameIndex operand, we need to use that
 	  // target machine register info object to eliminate it.
 	  MRI.eliminateFrameIndex(Fn, I);