int MipsSEFrameLowering::getFrameIndexReference(const MachineFunction &MF,
int FI,
unsigned &FrameReg) const {
const MachineFrameInfo *MFI = MF.getFrameInfo();
MipsABIInfo ABI = STI.getABI();
if (MFI->isFixedObjectIndex(FI))
FrameReg = hasFP(MF) ? ABI.GetFramePtr() : ABI.GetStackPtr();
else
FrameReg = hasBP(MF) ? ABI.GetBasePtr() : ABI.GetStackPtr();
return MFI->getObjectOffset(FI) + MFI->getStackSize() -
getOffsetOfLocalArea() + MFI->getOffsetAdjustment();
}
void MipsSERegisterInfo::eliminateFI(MachineBasicBlock::iterator II,
unsigned OpNo, int FrameIndex,
uint64_t StackSize,
int64_t SPOffset) const {
MachineInstr &MI = *II;
MachineFunction &MF = *MI.getParent()->getParent();
MachineFrameInfo *MFI = MF.getFrameInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
MipsABIInfo ABI =
static_cast<const MipsTargetMachine &>(MF.getTarget()).getABI();
const MipsRegisterInfo *RegInfo =
static_cast<const MipsRegisterInfo *>(MF.getSubtarget().getRegisterInfo());
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
int MinCSFI = 0;
int MaxCSFI = -1;
if (CSI.size()) {
MinCSFI = CSI[0].getFrameIdx();
MaxCSFI = CSI[CSI.size() - 1].getFrameIdx();
}
bool EhDataRegFI = MipsFI->isEhDataRegFI(FrameIndex);
// The following stack frame objects are always referenced relative to $sp:
// 1. Outgoing arguments.
// 2. Pointer to dynamically allocated stack space.
// 3. Locations for callee-saved registers.
// 4. Locations for eh data registers.
// Everything else is referenced relative to whatever register
// getFrameRegister() returns.
unsigned FrameReg;
if ((FrameIndex >= MinCSFI && FrameIndex <= MaxCSFI) || EhDataRegFI)
FrameReg = ABI.GetStackPtr();
else if (RegInfo->needsStackRealignment(MF)) {
if (MFI->hasVarSizedObjects() && !MFI->isFixedObjectIndex(FrameIndex))
FrameReg = ABI.GetBasePtr();
else if (MFI->isFixedObjectIndex(FrameIndex))
FrameReg = getFrameRegister(MF);
else
FrameReg = ABI.GetStackPtr();
} else
FrameReg = getFrameRegister(MF);
// Calculate final offset.
// - There is no need to change the offset if the frame object is one of the
// following: an outgoing argument, pointer to a dynamically allocated
// stack space or a $gp restore location,
// - If the frame object is any of the following, its offset must be adjusted
// by adding the size of the stack:
// incoming argument, callee-saved register location or local variable.
bool IsKill = false;
int64_t Offset;
Offset = SPOffset + (int64_t)StackSize;
Offset += MI.getOperand(OpNo + 1).getImm();
DEBUG(errs() << "Offset : " << Offset << "\n" << "<--------->\n");
if (!MI.isDebugValue()) {
// Make sure Offset fits within the field available.
// For MSA instructions, this is a 10-bit signed immediate (scaled by
// element size), otherwise it is a 16-bit signed immediate.
unsigned OffsetBitSize = getLoadStoreOffsetSizeInBits(MI.getOpcode());
unsigned OffsetAlign = getLoadStoreOffsetAlign(MI.getOpcode());
if (OffsetBitSize < 16 && isInt<16>(Offset) &&
(!isIntN(OffsetBitSize, Offset) ||
OffsetToAlignment(Offset, OffsetAlign) != 0)) {
// If we have an offset that needs to fit into a signed n-bit immediate
// (where n < 16) and doesn't, but does fit into 16-bits then use an ADDiu
MachineBasicBlock &MBB = *MI.getParent();
DebugLoc DL = II->getDebugLoc();
const TargetRegisterClass *PtrRC =
ABI.ArePtrs64bit() ? &Mips::GPR64RegClass : &Mips::GPR32RegClass;
MachineRegisterInfo &RegInfo = MBB.getParent()->getRegInfo();
unsigned Reg = RegInfo.createVirtualRegister(PtrRC);
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo *>(
MBB.getParent()->getSubtarget().getInstrInfo());
BuildMI(MBB, II, DL, TII.get(ABI.GetPtrAddiuOp()), Reg)
.addReg(FrameReg)
.addImm(Offset);
FrameReg = Reg;
Offset = 0;
IsKill = true;
} else if (!isInt<16>(Offset)) {
// Otherwise split the offset into 16-bit pieces and add it in multiple
// instructions.
MachineBasicBlock &MBB = *MI.getParent();
DebugLoc DL = II->getDebugLoc();
unsigned NewImm = 0;
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo *>(
MBB.getParent()->getSubtarget().getInstrInfo());
unsigned Reg = TII.loadImmediate(Offset, MBB, II, DL,
OffsetBitSize == 16 ? &NewImm : nullptr);
BuildMI(MBB, II, DL, TII.get(ABI.GetPtrAdduOp()), Reg).addReg(FrameReg)
.addReg(Reg, RegState::Kill);
FrameReg = Reg;
Offset = SignExtend64<16>(NewImm);
IsKill = true;
}
}
MI.getOperand(OpNo).ChangeToRegister(FrameReg, false, false, IsKill);
MI.getOperand(OpNo + 1).ChangeToImmediate(Offset);
}
