void
Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, RegScavenger *RS) const {
unsigned VReg = 0;
unsigned i = 0;
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
DebugLoc dl = MI.getDebugLoc();
while (!MI.getOperand(i).isFI()) {
++i;
assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
}
unsigned FrameReg = ARM::SP;
int FrameIndex = MI.getOperand(i).getIndex();
int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
MF.getFrameInfo()->getStackSize() + SPAdj;
if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
Offset -= AFI->getGPRCalleeSavedArea1Offset();
else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
Offset -= AFI->getGPRCalleeSavedArea2Offset();
else if (MF.getFrameInfo()->hasVarSizedObjects()) {
assert(SPAdj == 0 && MF.getTarget().getFrameInfo()->hasFP(MF) &&
"Unexpected");
// There are alloca()'s in this function, must reference off the frame
// pointer or base pointer instead.
if (!hasBasePointer(MF)) {
FrameReg = getFrameRegister(MF);
Offset -= AFI->getFramePtrSpillOffset();
} else
FrameReg = BasePtr;
}
// Special handling of dbg_value instructions.
if (MI.isDebugValue()) {
MI.getOperand(i). ChangeToRegister(FrameReg, false /*isDef*/);
MI.getOperand(i+1).ChangeToImmediate(Offset);
return;
}
// Modify MI as necessary to handle as much of 'Offset' as possible
assert(AFI->isThumbFunction() &&
"This eliminateFrameIndex only supports Thumb1!");
if (rewriteFrameIndex(MI, i, FrameReg, Offset, TII))
return;
// If we get here, the immediate doesn't fit into the instruction. We folded
// as much as possible above, handle the rest, providing a register that is
// SP+LargeImm.
assert(Offset && "This code isn't needed if offset already handled!");
unsigned Opcode = MI.getOpcode();
const TargetInstrDesc &Desc = MI.getDesc();
// Remove predicate first.
int PIdx = MI.findFirstPredOperandIdx();
if (PIdx != -1)
removeOperands(MI, PIdx);
if (Desc.mayLoad()) {
// Use the destination register to materialize sp + offset.
unsigned TmpReg = MI.getOperand(0).getReg();
bool UseRR = false;
if (Opcode == ARM::tRestore) {
if (FrameReg == ARM::SP)
emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg,
Offset, false, TII, *this, dl);
else {
emitLoadConstPool(MBB, II, dl, TmpReg, 0, Offset);
UseRR = true;
}
} else {
emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII,
*this, dl);
}
MI.setDesc(TII.get(ARM::tLDR));
MI.getOperand(i).ChangeToRegister(TmpReg, false, false, true);
if (UseRR)
// Use [reg, reg] addrmode.
MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
else // tLDR has an extra register operand.
MI.addOperand(MachineOperand::CreateReg(0, false));
} else if (Desc.mayStore()) {
VReg = MF.getRegInfo().createVirtualRegister(ARM::tGPRRegisterClass);
bool UseRR = false;
if (Opcode == ARM::tSpill) {
if (FrameReg == ARM::SP)
emitThumbRegPlusImmInReg(MBB, II, VReg, FrameReg,
Offset, false, TII, *this, dl);
else {
emitLoadConstPool(MBB, II, dl, VReg, 0, Offset);
UseRR = true;
}
} else
emitThumbRegPlusImmediate(MBB, II, VReg, FrameReg, Offset, TII,
*this, dl);
MI.setDesc(TII.get(ARM::tSTR));
MI.getOperand(i).ChangeToRegister(VReg, false, false, true);
if (UseRR) // Use [reg, reg] addrmode.
MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
else // tSTR has an extra register operand.
MI.addOperand(MachineOperand::CreateReg(0, false));
} else
assert(false && "Unexpected opcode!");
// Add predicate back if it's needed.
if (MI.getDesc().isPredicable()) {
MachineInstrBuilder MIB(&MI);
AddDefaultPred(MIB);
}
}
void
Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, unsigned FIOperandNum,
RegScavenger *RS) const {
unsigned VReg = 0;
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
const ARMBaseInstrInfo &TII =
*static_cast<const ARMBaseInstrInfo*>(MF.getTarget().getInstrInfo());
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
DebugLoc dl = MI.getDebugLoc();
MachineInstrBuilder MIB(*MBB.getParent(), &MI);
unsigned FrameReg = ARM::SP;
int FrameIndex = MI.getOperand(FIOperandNum).getIndex();
int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
MF.getFrameInfo()->getStackSize() + SPAdj;
if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
Offset -= AFI->getGPRCalleeSavedArea1Offset();
else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
Offset -= AFI->getGPRCalleeSavedArea2Offset();
else if (MF.getFrameInfo()->hasVarSizedObjects()) {
assert(SPAdj == 0 && MF.getTarget().getFrameLowering()->hasFP(MF) &&
"Unexpected");
// There are alloca()'s in this function, must reference off the frame
// pointer or base pointer instead.
if (!hasBasePointer(MF)) {
FrameReg = getFrameRegister(MF);
Offset -= AFI->getFramePtrSpillOffset();
} else
FrameReg = BasePtr;
}
// PEI::scavengeFrameVirtualRegs() cannot accurately track SPAdj because the
// call frame setup/destroy instructions have already been eliminated. That
// means the stack pointer cannot be used to access the emergency spill slot
// when !hasReservedCallFrame().
#ifndef NDEBUG
if (RS && FrameReg == ARM::SP && RS->isScavengingFrameIndex(FrameIndex)){
assert(MF.getTarget().getFrameLowering()->hasReservedCallFrame(MF) &&
"Cannot use SP to access the emergency spill slot in "
"functions without a reserved call frame");
assert(!MF.getFrameInfo()->hasVarSizedObjects() &&
"Cannot use SP to access the emergency spill slot in "
"functions with variable sized frame objects");
}
#endif // NDEBUG
// Special handling of dbg_value instructions.
if (MI.isDebugValue()) {
MI.getOperand(FIOperandNum). ChangeToRegister(FrameReg, false /*isDef*/);
MI.getOperand(FIOperandNum+1).ChangeToImmediate(Offset);
return;
}
// Modify MI as necessary to handle as much of 'Offset' as possible
assert(AFI->isThumbFunction() &&
"This eliminateFrameIndex only supports Thumb1!");
if (rewriteFrameIndex(MI, FIOperandNum, FrameReg, Offset, TII))
return;
// If we get here, the immediate doesn't fit into the instruction. We folded
// as much as possible above, handle the rest, providing a register that is
// SP+LargeImm.
assert(Offset && "This code isn't needed if offset already handled!");
unsigned Opcode = MI.getOpcode();
// Remove predicate first.
int PIdx = MI.findFirstPredOperandIdx();
if (PIdx != -1)
removeOperands(MI, PIdx);
if (MI.mayLoad()) {
// Use the destination register to materialize sp + offset.
unsigned TmpReg = MI.getOperand(0).getReg();
bool UseRR = false;
if (Opcode == ARM::tLDRspi) {
if (FrameReg == ARM::SP)
emitThumbRegPlusImmInReg(MBB, II, dl, TmpReg, FrameReg,
Offset, false, TII, *this);
else {
emitLoadConstPool(MBB, II, dl, TmpReg, 0, Offset);
UseRR = true;
}
} else {
emitThumbRegPlusImmediate(MBB, II, dl, TmpReg, FrameReg, Offset, TII,
*this);
}
MI.setDesc(TII.get(UseRR ? ARM::tLDRr : ARM::tLDRi));
MI.getOperand(FIOperandNum).ChangeToRegister(TmpReg, false, false, true);
if (UseRR)
// Use [reg, reg] addrmode. Replace the immediate operand w/ the frame
// register. The offset is already handled in the vreg value.
MI.getOperand(FIOperandNum+1).ChangeToRegister(FrameReg, false, false,
false);
} else if (MI.mayStore()) {
VReg = MF.getRegInfo().createVirtualRegister(&ARM::tGPRRegClass);
bool UseRR = false;
if (Opcode == ARM::tSTRspi) {
if (FrameReg == ARM::SP)
emitThumbRegPlusImmInReg(MBB, II, dl, VReg, FrameReg,
Offset, false, TII, *this);
else {
emitLoadConstPool(MBB, II, dl, VReg, 0, Offset);
UseRR = true;
}
} else
emitThumbRegPlusImmediate(MBB, II, dl, VReg, FrameReg, Offset, TII,
*this);
MI.setDesc(TII.get(UseRR ? ARM::tSTRr : ARM::tSTRi));
MI.getOperand(FIOperandNum).ChangeToRegister(VReg, false, false, true);
if (UseRR)
// Use [reg, reg] addrmode. Replace the immediate operand w/ the frame
// register. The offset is already handled in the vreg value.
MI.getOperand(FIOperandNum+1).ChangeToRegister(FrameReg, false, false,
false);
} else {
llvm_unreachable("Unexpected opcode!");
}
// Add predicate back if it's needed.
if (MI.isPredicable())
AddDefaultPred(MIB);
}
unsigned
Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
int SPAdj, int *Value,
RegScavenger *RS) const{
unsigned VReg = 0;
unsigned i = 0;
MachineInstr &MI = *II;
MachineBasicBlock &MBB = *MI.getParent();
MachineFunction &MF = *MBB.getParent();
ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
DebugLoc dl = MI.getDebugLoc();
while (!MI.getOperand(i).isFI()) {
++i;
assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
}
unsigned FrameReg = ARM::SP;
int FrameIndex = MI.getOperand(i).getIndex();
int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
MF.getFrameInfo()->getStackSize() + SPAdj;
if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
Offset -= AFI->getGPRCalleeSavedArea1Offset();
else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
Offset -= AFI->getGPRCalleeSavedArea2Offset();
else if (hasFP(MF)) {
assert(SPAdj == 0 && "Unexpected");
// There is alloca()'s in this function, must reference off the frame
// pointer instead.
FrameReg = getFrameRegister(MF);
Offset -= AFI->getFramePtrSpillOffset();
}
unsigned Opcode = MI.getOpcode();
const TargetInstrDesc &Desc = MI.getDesc();
unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
if (Opcode == ARM::tADDrSPi) {
Offset += MI.getOperand(i+1).getImm();
// Can't use tADDrSPi if it's based off the frame pointer.
unsigned NumBits = 0;
unsigned Scale = 1;
if (FrameReg != ARM::SP) {
Opcode = ARM::tADDi3;
MI.setDesc(TII.get(Opcode));
NumBits = 3;
} else {
NumBits = 8;
Scale = 4;
assert((Offset & 3) == 0 &&
"Thumb add/sub sp, #imm immediate must be multiple of 4!");
}
if (Offset == 0) {
// Turn it into a move.
MI.setDesc(TII.get(ARM::tMOVgpr2tgpr));
MI.getOperand(i).ChangeToRegister(FrameReg, false);
MI.RemoveOperand(i+1);
return 0;
}
// Common case: small offset, fits into instruction.
unsigned Mask = (1 << NumBits) - 1;
if (((Offset / Scale) & ~Mask) == 0) {
// Replace the FrameIndex with sp / fp
if (Opcode == ARM::tADDi3) {
removeOperands(MI, i);
MachineInstrBuilder MIB(&MI);
AddDefaultPred(AddDefaultT1CC(MIB).addReg(FrameReg)
.addImm(Offset / Scale));
} else {
MI.getOperand(i).ChangeToRegister(FrameReg, false);
MI.getOperand(i+1).ChangeToImmediate(Offset / Scale);
}
return 0;
}
unsigned DestReg = MI.getOperand(0).getReg();
unsigned Bytes = (Offset > 0) ? Offset : -Offset;
unsigned NumMIs = calcNumMI(Opcode, 0, Bytes, NumBits, Scale);
// MI would expand into a large number of instructions. Don't try to
// simplify the immediate.
if (NumMIs > 2) {
emitThumbRegPlusImmediate(MBB, II, DestReg, FrameReg, Offset, TII,
*this, dl);
MBB.erase(II);
return 0;
}
if (Offset > 0) {
// Translate r0 = add sp, imm to
// r0 = add sp, 255*4
// r0 = add r0, (imm - 255*4)
if (Opcode == ARM::tADDi3) {
removeOperands(MI, i);
MachineInstrBuilder MIB(&MI);
AddDefaultPred(AddDefaultT1CC(MIB).addReg(FrameReg).addImm(Mask));
} else {
MI.getOperand(i).ChangeToRegister(FrameReg, false);
MI.getOperand(i+1).ChangeToImmediate(Mask);
}
Offset = (Offset - Mask * Scale);
MachineBasicBlock::iterator NII = next(II);
emitThumbRegPlusImmediate(MBB, NII, DestReg, DestReg, Offset, TII,
*this, dl);
} else {
// Translate r0 = add sp, -imm to
// r0 = -imm (this is then translated into a series of instructons)
// r0 = add r0, sp
emitThumbConstant(MBB, II, DestReg, Offset, TII, *this, dl);
MI.setDesc(TII.get(ARM::tADDhirr));
MI.getOperand(i).ChangeToRegister(DestReg, false, false, true);
MI.getOperand(i+1).ChangeToRegister(FrameReg, false);
if (Opcode == ARM::tADDi3) {
MachineInstrBuilder MIB(&MI);
AddDefaultPred(MIB);
}
}
return 0;
} else {
unsigned ImmIdx = 0;
int InstrOffs = 0;
unsigned NumBits = 0;
unsigned Scale = 1;
switch (AddrMode) {
case ARMII::AddrModeT1_s: {
ImmIdx = i+1;
InstrOffs = MI.getOperand(ImmIdx).getImm();
NumBits = (FrameReg == ARM::SP) ? 8 : 5;
Scale = 4;
break;
}
default:
llvm_unreachable("Unsupported addressing mode!");
break;
}
Offset += InstrOffs * Scale;
assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
// Common case: small offset, fits into instruction.
MachineOperand &ImmOp = MI.getOperand(ImmIdx);
int ImmedOffset = Offset / Scale;
unsigned Mask = (1 << NumBits) - 1;
if ((unsigned)Offset <= Mask * Scale) {
// Replace the FrameIndex with sp
MI.getOperand(i).ChangeToRegister(FrameReg, false);
ImmOp.ChangeToImmediate(ImmedOffset);
return 0;
}
bool isThumSpillRestore = Opcode == ARM::tRestore || Opcode == ARM::tSpill;
if (AddrMode == ARMII::AddrModeT1_s) {
// Thumb tLDRspi, tSTRspi. These will change to instructions that use
// a different base register.
NumBits = 5;
Mask = (1 << NumBits) - 1;
}
// If this is a thumb spill / restore, we will be using a constpool load to
// materialize the offset.
if (AddrMode == ARMII::AddrModeT1_s && isThumSpillRestore)
ImmOp.ChangeToImmediate(0);
else {
// Otherwise, it didn't fit. Pull in what we can to simplify the immed.
ImmedOffset = ImmedOffset & Mask;
ImmOp.ChangeToImmediate(ImmedOffset);
Offset &= ~(Mask*Scale);
}
}
// If we get here, the immediate doesn't fit into the instruction. We folded
// as much as possible above, handle the rest, providing a register that is
// SP+LargeImm.
assert(Offset && "This code isn't needed if offset already handled!");
// Remove predicate first.
int PIdx = MI.findFirstPredOperandIdx();
if (PIdx != -1)
removeOperands(MI, PIdx);
if (Desc.mayLoad()) {
// Use the destination register to materialize sp + offset.
unsigned TmpReg = MI.getOperand(0).getReg();
bool UseRR = false;
if (Opcode == ARM::tRestore) {
if (FrameReg == ARM::SP)
emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg,
Offset, false, TII, *this, dl);
else {
emitLoadConstPool(MBB, II, dl, TmpReg, 0, Offset);
UseRR = true;
}
} else {
emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII,
*this, dl);
}
MI.setDesc(TII.get(ARM::tLDR));
MI.getOperand(i).ChangeToRegister(TmpReg, false, false, true);
if (UseRR)
// Use [reg, reg] addrmode.
MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
else // tLDR has an extra register operand.
MI.addOperand(MachineOperand::CreateReg(0, false));
} else if (Desc.mayStore()) {
VReg = MF.getRegInfo().createVirtualRegister(ARM::tGPRRegisterClass);
assert (Value && "Frame index virtual allocated, but Value arg is NULL!");
*Value = Offset;
bool UseRR = false;
if (Opcode == ARM::tSpill) {
if (FrameReg == ARM::SP)
emitThumbRegPlusImmInReg(MBB, II, VReg, FrameReg,
Offset, false, TII, *this, dl);
else {
emitLoadConstPool(MBB, II, dl, VReg, 0, Offset);
UseRR = true;
}
} else
emitThumbRegPlusImmediate(MBB, II, VReg, FrameReg, Offset, TII,
*this, dl);
MI.setDesc(TII.get(ARM::tSTR));
MI.getOperand(i).ChangeToRegister(VReg, false, false, true);
if (UseRR) // Use [reg, reg] addrmode.
MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
else // tSTR has an extra register operand.
MI.addOperand(MachineOperand::CreateReg(0, false));
} else
assert(false && "Unexpected opcode!");
// Add predicate back if it's needed.
if (MI.getDesc().isPredicable()) {
MachineInstrBuilder MIB(&MI);
AddDefaultPred(MIB);
}
return VReg;
}
