Move estimateStackSize from ARM into MachineFrameInfo

This is a generic function (derived from PEI); moving it into
MachineFrameInfo eliminates a current redundancy between the ARM and AArch64
backends, and will allow it to be used by the PowerPC target code.

No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177111 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Hal Finkel
2013-03-14 21:15:20 +00:00
parent 3080d23fde
commit 0cc52c67db
4 changed files with 55 additions and 108 deletions

View File

@ -574,6 +574,54 @@ MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
return BV;
}
unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const {
const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
unsigned MaxAlign = getMaxAlignment();
int Offset = 0;
// This code is very, very similar to PEI::calculateFrameObjectOffsets().
// It really should be refactored to share code. Until then, changes
// should keep in mind that there's tight coupling between the two.
for (int i = getObjectIndexBegin(); i != 0; ++i) {
int FixedOff = -getObjectOffset(i);
if (FixedOff > Offset) Offset = FixedOff;
}
for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
if (isDeadObjectIndex(i))
continue;
Offset += getObjectSize(i);
unsigned Align = getObjectAlignment(i);
// Adjust to alignment boundary
Offset = (Offset+Align-1)/Align*Align;
MaxAlign = std::max(Align, MaxAlign);
}
if (adjustsStack() && TFI->hasReservedCallFrame(MF))
Offset += getMaxCallFrameSize();
// Round up the size to a multiple of the alignment. If the function has
// any calls or alloca's, align to the target's StackAlignment value to
// ensure that the callee's frame or the alloca data is suitably aligned;
// otherwise, for leaf functions, align to the TransientStackAlignment
// value.
unsigned StackAlign;
if (adjustsStack() || hasVarSizedObjects() ||
(RegInfo->needsStackRealignment(MF) && getObjectIndexEnd() != 0))
StackAlign = TFI->getStackAlignment();
else
StackAlign = TFI->getTransientStackAlignment();
// If the frame pointer is eliminated, all frame offsets will be relative to
// SP not FP. Align to MaxAlign so this works.
StackAlign = std::max(StackAlign, MaxAlign);
unsigned AlignMask = StackAlign - 1;
Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
return (unsigned)Offset;
}
void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
if (Objects.empty()) return;