//===-- PrologEpilogInserter.cpp - Insert Prolog/Epilog code in function --===//
-//
+//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
-//
+//
//===----------------------------------------------------------------------===//
//
// This pass is responsible for finalizing the functions frame layout, saving
void PEI::calculateCallerSavedRegisters(MachineFunction &Fn) {
const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
const TargetFrameInfo *TFI = Fn.getTarget().getFrameInfo();
+ const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
// Get the callee saved register list...
const unsigned *CSRegs = RegInfo->getCalleeSaveRegs();
FrameSetupOpcode == -1 && FrameDestroyOpcode == -1)
return;
- // This bitset contains an entry for each physical register for the target...
- std::vector<bool> ModifiedRegs(RegInfo->getNumRegs());
unsigned MaxCallFrameSize = 0;
bool HasCalls = false;
HasCalls = true;
RegInfo->eliminateCallFramePseudoInstr(Fn, *BB, I++);
} else {
- 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!");
- ModifiedRegs[MO.getReg()] = true; // Register is modified
- }
- }
++I;
}
// Now figure out which *callee saved* registers are modified by the current
// function, thus needing to be saved and restored in the prolog/epilog.
//
+ const bool *PhysRegsUsed = Fn.getUsedPhysregs();
for (unsigned i = 0; CSRegs[i]; ++i) {
unsigned Reg = CSRegs[i];
- if (ModifiedRegs[Reg]) {
- RegsToSave.push_back(Reg); // If modified register...
+ if (PhysRegsUsed[Reg]) {
+ RegsToSave.push_back(Reg); // If the reg is modified, save it!
} else {
for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg);
- *AliasSet; ++AliasSet) { // Check alias registers too...
- if (ModifiedRegs[*AliasSet]) {
+ *AliasSet; ++AliasSet) { // Check alias registers too.
+ if (PhysRegsUsed[*AliasSet]) {
RegsToSave.push_back(Reg);
break;
}
int FrameIdx;
if (FixedSlot == FixedSpillSlots+NumFixedSpillSlots) {
// Nope, just spill it anywhere convenient.
- FrameIdx = FFI->CreateStackObject(RegInfo->getSpillSize(Reg),
- RegInfo->getSpillAlignment(Reg));
+ FrameIdx = FFI->CreateStackObject(RegInfo->getSpillSize(Reg)/8,
+ RegInfo->getSpillAlignment(Reg)/8);
} else {
// Spill it to the stack where we must.
- FrameIdx = FFI->CreateFixedObject(RegInfo->getSpillSize(Reg),
+ FrameIdx = FFI->CreateFixedObject(RegInfo->getSpillSize(Reg)/8,
FixedSlot->second);
}
StackSlots.push_back(FrameIdx);
void PEI::saveCallerSavedRegisters(MachineFunction &Fn) {
// Early exit if no caller saved registers are modified!
if (RegsToSave.empty())
- return;
+ return;
const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
// Now that we have a stack slot for each register to be saved, insert spill
- // code into the entry block...
+ // code into the entry block.
MachineBasicBlock *MBB = Fn.begin();
MachineBasicBlock::iterator I = MBB->begin();
for (unsigned i = 0, e = RegsToSave.size(); i != e; ++i) {
// Add code to restore the callee-save registers in each exiting block.
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
+ 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(); --I;
for (unsigned i = 0, e = RegsToSave.size(); i != e; ++i) {
- RegInfo->loadRegFromStackSlot(*MBB, I, RegsToSave[i],StackSlots[i]);
+ RegInfo->loadRegFromStackSlot(*MBB, I, RegsToSave[i], StackSlots[i]);
+ assert(I != MBB->begin() &&
+ "loadRegFromStackSlot didn't insert any code!");
--I; // Insert in reverse order
}
}
- }
}
/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the
-/// abstract stack objects...
+/// abstract stack objects.
///
void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
const TargetFrameInfo &TFI = *Fn.getTarget().getFrameInfo();
-
+
bool StackGrowsDown =
TFI.getStackGrowthDirection() == TargetFrameInfo::StackGrowsDown;
-
+
// Loop over all of the stack objects, assigning sequential addresses...
MachineFrameInfo *FFI = Fn.getFrameInfo();
int Offset = TFI.getOffsetOfLocalArea();
if (StackGrowsDown)
Offset = -Offset;
- assert(Offset >= 0
+ assert(Offset >= 0
&& "Local area offset should be in direction of stack growth");
// If there are fixed sized objects that are preallocated in the local area,
// non-fixed objects can't be allocated right at the start of local area.
- // We currently don't support filling in holes in between fixed sized objects,
+ // We currently don't support filling in holes in between fixed sized objects,
// so we adjust 'Offset' to point to the end of last fixed sized
// preallocated object.
for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) {
// the offset is negative, so we negate the offset to get the distance.
FixedOff = -FFI->getObjectOffset(i);
} else {
- // The maximum distance from the start pointer is at the upper
+ // The maximum distance from the start pointer is at the upper
// address of the object.
FixedOff = FFI->getObjectOffset(i) + FFI->getObjectSize(i);
- }
- if (FixedOff > Offset) Offset = FixedOff;
+ }
+ if (FixedOff > Offset) Offset = FixedOff;
}
for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
assert(Align <= StackAlignment && "Cannot align stack object to higher "
"alignment boundary than the stack itself!");
Offset = (Offset+Align-1)/Align*Align; // Adjust to Alignment boundary...
-
+
if (StackGrowsDown) {
FFI->setObjectOffset(i, -Offset); // Set the computed offset
} else {
- FFI->setObjectOffset(i, Offset);
+ FFI->setObjectOffset(i, Offset);
Offset += FFI->getObjectSize(i);
}
}
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