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 MipsSEFrameLowering::emitEpilogue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
MachineFrameInfo *MFI = MF.getFrameInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo *>(STI.getInstrInfo());
const MipsRegisterInfo &RegInfo =
*static_cast<const MipsRegisterInfo *>(STI.getRegisterInfo());
DebugLoc DL = MBBI->getDebugLoc();
MipsABIInfo ABI = STI.getABI();
unsigned SP = ABI.GetStackPtr();
unsigned FP = ABI.GetFramePtr();
unsigned ZERO = ABI.GetNullPtr();
unsigned MOVE = ABI.GetGPRMoveOp();
// if framepointer enabled, restore the stack pointer.
if (hasFP(MF)) {
// Find the first instruction that restores a callee-saved register.
MachineBasicBlock::iterator I = MBBI;
for (unsigned i = 0; i < MFI->getCalleeSavedInfo().size(); ++i)
--I;
// Insert instruction "move $sp, $fp" at this location.
BuildMI(MBB, I, DL, TII.get(MOVE), SP).addReg(FP).addReg(ZERO);
}
if (MipsFI->callsEhReturn()) {
const TargetRegisterClass *RC =
ABI.ArePtrs64bit() ? &Mips::GPR64RegClass : &Mips::GPR32RegClass;
// Find first instruction that restores a callee-saved register.
MachineBasicBlock::iterator I = MBBI;
for (unsigned i = 0; i < MFI->getCalleeSavedInfo().size(); ++i)
--I;
// Insert instructions that restore eh data registers.
for (int J = 0; J < 4; ++J) {
TII.loadRegFromStackSlot(MBB, I, ABI.GetEhDataReg(J),
MipsFI->getEhDataRegFI(J), RC, &RegInfo);
}
}
if (MF.getFunction()->hasFnAttribute("interrupt"))
emitInterruptEpilogueStub(MF, MBB);
// Get the number of bytes from FrameInfo
uint64_t StackSize = MFI->getStackSize();
if (!StackSize)
return;
// Adjust stack.
TII.adjustStackPtr(SP, StackSize, MBB, MBBI);
}
void MipsSEFrameLowering::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB) const {
assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
MachineFrameInfo *MFI = MF.getFrameInfo();
MipsFunctionInfo *MipsFI = MF.getInfo<MipsFunctionInfo>();
const MipsSEInstrInfo &TII =
*static_cast<const MipsSEInstrInfo *>(STI.getInstrInfo());
const MipsRegisterInfo &RegInfo =
*static_cast<const MipsRegisterInfo *>(STI.getRegisterInfo());
MachineBasicBlock::iterator MBBI = MBB.begin();
DebugLoc dl;
MipsABIInfo ABI = STI.getABI();
unsigned SP = ABI.GetStackPtr();
unsigned FP = ABI.GetFramePtr();
unsigned ZERO = ABI.GetNullPtr();
unsigned MOVE = ABI.GetGPRMoveOp();
unsigned ADDiu = ABI.GetPtrAddiuOp();
unsigned AND = ABI.IsN64() ? Mips::AND64 : Mips::AND;
const TargetRegisterClass *RC = ABI.ArePtrs64bit() ?
&Mips::GPR64RegClass : &Mips::GPR32RegClass;
// First, compute final stack size.
uint64_t StackSize = MFI->getStackSize();
// No need to allocate space on the stack.
if (StackSize == 0 && !MFI->adjustsStack()) return;
MachineModuleInfo &MMI = MF.getMMI();
const MCRegisterInfo *MRI = MMI.getContext().getRegisterInfo();
MachineLocation DstML, SrcML;
// Adjust stack.
TII.adjustStackPtr(SP, -StackSize, MBB, MBBI);
// emit ".cfi_def_cfa_offset StackSize"
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createDefCfaOffset(nullptr, -StackSize));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
if (MF.getFunction()->hasFnAttribute("interrupt"))
emitInterruptPrologueStub(MF, MBB);
const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
if (CSI.size()) {
// Find the instruction past the last instruction that saves a callee-saved
// register to the stack.
for (unsigned i = 0; i < CSI.size(); ++i)
++MBBI;
// Iterate over list of callee-saved registers and emit .cfi_offset
// directives.
for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
E = CSI.end(); I != E; ++I) {
int64_t Offset = MFI->getObjectOffset(I->getFrameIdx());
unsigned Reg = I->getReg();
// If Reg is a double precision register, emit two cfa_offsets,
// one for each of the paired single precision registers.
if (Mips::AFGR64RegClass.contains(Reg)) {
unsigned Reg0 =
MRI->getDwarfRegNum(RegInfo.getSubReg(Reg, Mips::sub_lo), true);
unsigned Reg1 =
MRI->getDwarfRegNum(RegInfo.getSubReg(Reg, Mips::sub_hi), true);
if (!STI.isLittle())
std::swap(Reg0, Reg1);
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createOffset(nullptr, Reg0, Offset));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createOffset(nullptr, Reg1, Offset + 4));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
} else if (Mips::FGR64RegClass.contains(Reg)) {
unsigned Reg0 = MRI->getDwarfRegNum(Reg, true);
unsigned Reg1 = MRI->getDwarfRegNum(Reg, true) + 1;
if (!STI.isLittle())
std::swap(Reg0, Reg1);
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createOffset(nullptr, Reg0, Offset));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createOffset(nullptr, Reg1, Offset + 4));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
} else {
// Reg is either in GPR32 or FGR32.
unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createOffset(
nullptr, MRI->getDwarfRegNum(Reg, 1), Offset));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
}
}
if (MipsFI->callsEhReturn()) {
// Insert instructions that spill eh data registers.
for (int I = 0; I < 4; ++I) {
if (!MBB.isLiveIn(ABI.GetEhDataReg(I)))
MBB.addLiveIn(ABI.GetEhDataReg(I));
TII.storeRegToStackSlot(MBB, MBBI, ABI.GetEhDataReg(I), false,
MipsFI->getEhDataRegFI(I), RC, &RegInfo);
}
// Emit .cfi_offset directives for eh data registers.
for (int I = 0; I < 4; ++I) {
int64_t Offset = MFI->getObjectOffset(MipsFI->getEhDataRegFI(I));
unsigned Reg = MRI->getDwarfRegNum(ABI.GetEhDataReg(I), true);
unsigned CFIIndex = MMI.addFrameInst(
MCCFIInstruction::createOffset(nullptr, Reg, Offset));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
}
}
// if framepointer enabled, set it to point to the stack pointer.
if (hasFP(MF)) {
// Insert instruction "move $fp, $sp" at this location.
BuildMI(MBB, MBBI, dl, TII.get(MOVE), FP).addReg(SP).addReg(ZERO)
.setMIFlag(MachineInstr::FrameSetup);
// emit ".cfi_def_cfa_register $fp"
unsigned CFIIndex = MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(
nullptr, MRI->getDwarfRegNum(FP, true)));
BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
.addCFIIndex(CFIIndex);
if (RegInfo.needsStackRealignment(MF)) {
// addiu $Reg, $zero, -MaxAlignment
// andi $sp, $sp, $Reg
unsigned VR = MF.getRegInfo().createVirtualRegister(RC);
assert(isInt<16>(MFI->getMaxAlignment()) &&
"Function's alignment size requirement is not supported.");
int MaxAlign = - (signed) MFI->getMaxAlignment();
BuildMI(MBB, MBBI, dl, TII.get(ADDiu), VR).addReg(ZERO) .addImm(MaxAlign);
BuildMI(MBB, MBBI, dl, TII.get(AND), SP).addReg(SP).addReg(VR);
if (hasBP(MF)) {
// move $s7, $sp
unsigned BP = STI.isABI_N64() ? Mips::S7_64 : Mips::S7;
BuildMI(MBB, MBBI, dl, TII.get(MOVE), BP)
.addReg(SP)
.addReg(ZERO);
}
}
}
}
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);
}
