1 //===- Thumb1RegisterInfo.cpp - Thumb-1 Register Information ----*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the Thumb-1 implementation of the TargetRegisterInfo
13 //===----------------------------------------------------------------------===//
16 #include "ARMAddressingModes.h"
17 #include "ARMBaseInstrInfo.h"
18 #include "ARMMachineFunctionInfo.h"
19 #include "ARMSubtarget.h"
20 #include "Thumb1InstrInfo.h"
21 #include "Thumb1RegisterInfo.h"
22 #include "llvm/Constants.h"
23 #include "llvm/DerivedTypes.h"
24 #include "llvm/Function.h"
25 #include "llvm/LLVMContext.h"
26 #include "llvm/CodeGen/MachineConstantPool.h"
27 #include "llvm/CodeGen/MachineFrameInfo.h"
28 #include "llvm/CodeGen/MachineFunction.h"
29 #include "llvm/CodeGen/MachineInstrBuilder.h"
30 #include "llvm/CodeGen/MachineLocation.h"
31 #include "llvm/CodeGen/MachineRegisterInfo.h"
32 #include "llvm/Target/TargetFrameInfo.h"
33 #include "llvm/Target/TargetMachine.h"
34 #include "llvm/ADT/BitVector.h"
35 #include "llvm/ADT/SmallVector.h"
36 #include "llvm/Support/CommandLine.h"
37 #include "llvm/Support/ErrorHandling.h"
38 #include "llvm/Support/raw_ostream.h"
41 extern cl::opt<bool> ReuseFrameIndexVals;
46 Thumb1RegisterInfo::Thumb1RegisterInfo(const ARMBaseInstrInfo &tii,
47 const ARMSubtarget &sti)
48 : ARMBaseRegisterInfo(tii, sti) {
51 /// emitLoadConstPool - Emits a load from constpool to materialize the
52 /// specified immediate.
53 void Thumb1RegisterInfo::emitLoadConstPool(MachineBasicBlock &MBB,
54 MachineBasicBlock::iterator &MBBI,
56 unsigned DestReg, unsigned SubIdx,
58 ARMCC::CondCodes Pred,
59 unsigned PredReg) const {
60 MachineFunction &MF = *MBB.getParent();
61 MachineConstantPool *ConstantPool = MF.getConstantPool();
62 const Constant *C = ConstantInt::get(
63 Type::getInt32Ty(MBB.getParent()->getFunction()->getContext()), Val);
64 unsigned Idx = ConstantPool->getConstantPoolIndex(C, 4);
66 BuildMI(MBB, MBBI, dl, TII.get(ARM::tLDRcp))
67 .addReg(DestReg, getDefRegState(true), SubIdx)
68 .addConstantPoolIndex(Idx).addImm(Pred).addReg(PredReg);
72 /// emitThumbRegPlusImmInReg - Emits a series of instructions to materialize
73 /// a destreg = basereg + immediate in Thumb code. Materialize the immediate
74 /// in a register using mov / mvn sequences or load the immediate from a
77 void emitThumbRegPlusImmInReg(MachineBasicBlock &MBB,
78 MachineBasicBlock::iterator &MBBI,
79 unsigned DestReg, unsigned BaseReg,
80 int NumBytes, bool CanChangeCC,
81 const TargetInstrInfo &TII,
82 const ARMBaseRegisterInfo& MRI,
84 MachineFunction &MF = *MBB.getParent();
85 bool isHigh = !isARMLowRegister(DestReg) ||
86 (BaseReg != 0 && !isARMLowRegister(BaseReg));
88 // Subtract doesn't have high register version. Load the negative value
89 // if either base or dest register is a high register. Also, if do not
90 // issue sub as part of the sequence if condition register is to be
92 if (NumBytes < 0 && !isHigh && CanChangeCC) {
96 unsigned LdReg = DestReg;
97 if (DestReg == ARM::SP) {
98 assert(BaseReg == ARM::SP && "Unexpected!");
99 LdReg = MF.getRegInfo().createVirtualRegister(ARM::tGPRRegisterClass);
102 if (NumBytes <= 255 && NumBytes >= 0)
103 AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVi8), LdReg))
105 else if (NumBytes < 0 && NumBytes >= -255) {
106 AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVi8), LdReg))
108 AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII.get(ARM::tRSB), LdReg))
109 .addReg(LdReg, RegState::Kill);
111 MRI.emitLoadConstPool(MBB, MBBI, dl, LdReg, 0, NumBytes);
114 int Opc = (isSub) ? ARM::tSUBrr : (isHigh ? ARM::tADDhirr : ARM::tADDrr);
115 MachineInstrBuilder MIB =
116 BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg);
117 if (Opc != ARM::tADDhirr)
118 MIB = AddDefaultT1CC(MIB);
119 if (DestReg == ARM::SP || isSub)
120 MIB.addReg(BaseReg).addReg(LdReg, RegState::Kill);
122 MIB.addReg(LdReg).addReg(BaseReg, RegState::Kill);
126 /// calcNumMI - Returns the number of instructions required to materialize
127 /// the specific add / sub r, c instruction.
128 static unsigned calcNumMI(int Opc, int ExtraOpc, unsigned Bytes,
129 unsigned NumBits, unsigned Scale) {
131 unsigned Chunk = ((1 << NumBits) - 1) * Scale;
133 if (Opc == ARM::tADDrSPi) {
134 unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
138 Scale = 1; // Followed by a number of tADDi8.
139 Chunk = ((1 << NumBits) - 1) * Scale;
142 NumMIs += Bytes / Chunk;
143 if ((Bytes % Chunk) != 0)
150 /// emitThumbRegPlusImmediate - Emits a series of instructions to materialize
151 /// a destreg = basereg + immediate in Thumb code.
152 void llvm::emitThumbRegPlusImmediate(MachineBasicBlock &MBB,
153 MachineBasicBlock::iterator &MBBI,
154 unsigned DestReg, unsigned BaseReg,
155 int NumBytes, const TargetInstrInfo &TII,
156 const ARMBaseRegisterInfo& MRI,
158 bool isSub = NumBytes < 0;
159 unsigned Bytes = (unsigned)NumBytes;
160 if (isSub) Bytes = -NumBytes;
161 bool isMul4 = (Bytes & 3) == 0;
162 bool isTwoAddr = false;
163 bool DstNotEqBase = false;
164 unsigned NumBits = 1;
169 bool NeedPred = false;
171 if (DestReg == BaseReg && BaseReg == ARM::SP) {
172 assert(isMul4 && "Thumb sp inc / dec size must be multiple of 4!");
175 Opc = isSub ? ARM::tSUBspi : ARM::tADDspi;
177 } else if (!isSub && BaseReg == ARM::SP) {
180 // r1 = add sp, 100 * 4
184 ExtraOpc = ARM::tADDi3;
193 if (DestReg != BaseReg)
196 if (DestReg == ARM::SP) {
197 Opc = isSub ? ARM::tSUBspi : ARM::tADDspi;
198 assert(isMul4 && "Thumb sp inc / dec size must be multiple of 4!");
202 Opc = isSub ? ARM::tSUBi8 : ARM::tADDi8;
204 NeedPred = NeedCC = true;
209 unsigned NumMIs = calcNumMI(Opc, ExtraOpc, Bytes, NumBits, Scale);
210 unsigned Threshold = (DestReg == ARM::SP) ? 3 : 2;
211 if (NumMIs > Threshold) {
212 // This will expand into too many instructions. Load the immediate from a
214 emitThumbRegPlusImmInReg(MBB, MBBI, DestReg, BaseReg, NumBytes, true, TII,
220 if (isARMLowRegister(DestReg) && isARMLowRegister(BaseReg)) {
221 // If both are low registers, emit DestReg = add BaseReg, max(Imm, 7)
222 unsigned Chunk = (1 << 3) - 1;
223 unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
225 const TargetInstrDesc &TID = TII.get(isSub ? ARM::tSUBi3 : ARM::tADDi3);
226 const MachineInstrBuilder MIB =
227 AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TID, DestReg));
228 AddDefaultPred(MIB.addReg(BaseReg, RegState::Kill).addImm(ThisVal));
230 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), DestReg)
231 .addReg(BaseReg, RegState::Kill);
236 unsigned Chunk = ((1 << NumBits) - 1) * Scale;
238 unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
241 // Build the new tADD / tSUB.
243 MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg);
245 MIB = AddDefaultT1CC(MIB);
246 MIB .addReg(DestReg).addImm(ThisVal);
248 MIB = AddDefaultPred(MIB);
251 bool isKill = BaseReg != ARM::SP;
252 MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg);
254 MIB = AddDefaultT1CC(MIB);
255 MIB.addReg(BaseReg, getKillRegState(isKill)).addImm(ThisVal);
257 MIB = AddDefaultPred(MIB);
260 if (Opc == ARM::tADDrSPi) {
266 Chunk = ((1 << NumBits) - 1) * Scale;
267 Opc = isSub ? ARM::tSUBi8 : ARM::tADDi8;
268 NeedPred = NeedCC = isTwoAddr = true;
274 const TargetInstrDesc &TID = TII.get(ExtraOpc);
275 AddDefaultPred(AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TID, DestReg))
276 .addReg(DestReg, RegState::Kill)
277 .addImm(((unsigned)NumBytes) & 3));
281 static void emitSPUpdate(MachineBasicBlock &MBB,
282 MachineBasicBlock::iterator &MBBI,
283 const TargetInstrInfo &TII, DebugLoc dl,
284 const Thumb1RegisterInfo &MRI,
286 emitThumbRegPlusImmediate(MBB, MBBI, ARM::SP, ARM::SP, NumBytes, TII,
290 void Thumb1RegisterInfo::
291 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
292 MachineBasicBlock::iterator I) const {
293 const TargetFrameInfo *TFI = MF.getTarget().getFrameInfo();
295 if (!TFI->hasReservedCallFrame(MF)) {
296 // If we have alloca, convert as follows:
297 // ADJCALLSTACKDOWN -> sub, sp, sp, amount
298 // ADJCALLSTACKUP -> add, sp, sp, amount
299 MachineInstr *Old = I;
300 DebugLoc dl = Old->getDebugLoc();
301 unsigned Amount = Old->getOperand(0).getImm();
303 // We need to keep the stack aligned properly. To do this, we round the
304 // amount of space needed for the outgoing arguments up to the next
305 // alignment boundary.
306 unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
307 Amount = (Amount+Align-1)/Align*Align;
309 // Replace the pseudo instruction with a new instruction...
310 unsigned Opc = Old->getOpcode();
311 if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) {
312 emitSPUpdate(MBB, I, TII, dl, *this, -Amount);
314 assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP);
315 emitSPUpdate(MBB, I, TII, dl, *this, Amount);
322 /// emitThumbConstant - Emit a series of instructions to materialize a
324 static void emitThumbConstant(MachineBasicBlock &MBB,
325 MachineBasicBlock::iterator &MBBI,
326 unsigned DestReg, int Imm,
327 const TargetInstrInfo &TII,
328 const Thumb1RegisterInfo& MRI,
330 bool isSub = Imm < 0;
331 if (isSub) Imm = -Imm;
333 int Chunk = (1 << 8) - 1;
334 int ThisVal = (Imm > Chunk) ? Chunk : Imm;
336 AddDefaultPred(AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVi8),
340 emitThumbRegPlusImmediate(MBB, MBBI, DestReg, DestReg, Imm, TII, MRI, dl);
342 const TargetInstrDesc &TID = TII.get(ARM::tRSB);
343 AddDefaultPred(AddDefaultT1CC(BuildMI(MBB, MBBI, dl, TID, DestReg))
344 .addReg(DestReg, RegState::Kill));
348 static void removeOperands(MachineInstr &MI, unsigned i) {
350 for (unsigned e = MI.getNumOperands(); i != e; ++i)
351 MI.RemoveOperand(Op);
354 /// convertToNonSPOpcode - Change the opcode to the non-SP version, because
355 /// we're replacing the frame index with a non-SP register.
356 static unsigned convertToNonSPOpcode(unsigned Opcode) {
368 bool Thumb1RegisterInfo::
369 rewriteFrameIndex(MachineBasicBlock::iterator II, unsigned FrameRegIdx,
370 unsigned FrameReg, int &Offset,
371 const ARMBaseInstrInfo &TII) const {
372 MachineInstr &MI = *II;
373 MachineBasicBlock &MBB = *MI.getParent();
374 DebugLoc dl = MI.getDebugLoc();
375 unsigned Opcode = MI.getOpcode();
376 const TargetInstrDesc &Desc = MI.getDesc();
377 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
379 if (Opcode == ARM::tADDrSPi) {
380 Offset += MI.getOperand(FrameRegIdx+1).getImm();
382 // Can't use tADDrSPi if it's based off the frame pointer.
383 unsigned NumBits = 0;
385 if (FrameReg != ARM::SP) {
386 Opcode = ARM::tADDi3;
387 MI.setDesc(TII.get(Opcode));
392 assert((Offset & 3) == 0 &&
393 "Thumb add/sub sp, #imm immediate must be multiple of 4!");
397 if (Offset == 0 && getInstrPredicate(&MI, PredReg) == ARMCC::AL) {
398 // Turn it into a move.
399 MI.setDesc(TII.get(ARM::tMOVgpr2tgpr));
400 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
401 // Remove offset and remaining explicit predicate operands.
402 do MI.RemoveOperand(FrameRegIdx+1);
403 while (MI.getNumOperands() > FrameRegIdx+1 &&
404 (!MI.getOperand(FrameRegIdx+1).isReg() ||
405 !MI.getOperand(FrameRegIdx+1).isImm()));
409 // Common case: small offset, fits into instruction.
410 unsigned Mask = (1 << NumBits) - 1;
411 if (((Offset / Scale) & ~Mask) == 0) {
412 // Replace the FrameIndex with sp / fp
413 if (Opcode == ARM::tADDi3) {
414 removeOperands(MI, FrameRegIdx);
415 MachineInstrBuilder MIB(&MI);
416 AddDefaultPred(AddDefaultT1CC(MIB).addReg(FrameReg)
417 .addImm(Offset / Scale));
419 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
420 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset / Scale);
425 unsigned DestReg = MI.getOperand(0).getReg();
426 unsigned Bytes = (Offset > 0) ? Offset : -Offset;
427 unsigned NumMIs = calcNumMI(Opcode, 0, Bytes, NumBits, Scale);
428 // MI would expand into a large number of instructions. Don't try to
429 // simplify the immediate.
431 emitThumbRegPlusImmediate(MBB, II, DestReg, FrameReg, Offset, TII,
438 // Translate r0 = add sp, imm to
439 // r0 = add sp, 255*4
440 // r0 = add r0, (imm - 255*4)
441 if (Opcode == ARM::tADDi3) {
442 removeOperands(MI, FrameRegIdx);
443 MachineInstrBuilder MIB(&MI);
444 AddDefaultPred(AddDefaultT1CC(MIB).addReg(FrameReg).addImm(Mask));
446 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
447 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Mask);
449 Offset = (Offset - Mask * Scale);
450 MachineBasicBlock::iterator NII = llvm::next(II);
451 emitThumbRegPlusImmediate(MBB, NII, DestReg, DestReg, Offset, TII,
454 // Translate r0 = add sp, -imm to
455 // r0 = -imm (this is then translated into a series of instructons)
457 emitThumbConstant(MBB, II, DestReg, Offset, TII, *this, dl);
459 MI.setDesc(TII.get(ARM::tADDhirr));
460 MI.getOperand(FrameRegIdx).ChangeToRegister(DestReg, false, false, true);
461 MI.getOperand(FrameRegIdx+1).ChangeToRegister(FrameReg, false);
462 if (Opcode == ARM::tADDi3) {
463 MachineInstrBuilder MIB(&MI);
469 if (AddrMode != ARMII::AddrModeT1_s)
470 llvm_unreachable("Unsupported addressing mode!");
472 unsigned ImmIdx = FrameRegIdx + 1;
473 int InstrOffs = MI.getOperand(ImmIdx).getImm();
474 unsigned NumBits = (FrameReg == ARM::SP) ? 8 : 5;
477 Offset += InstrOffs * Scale;
478 assert((Offset & (Scale - 1)) == 0 && "Can't encode this offset!");
480 // Common case: small offset, fits into instruction.
481 MachineOperand &ImmOp = MI.getOperand(ImmIdx);
482 int ImmedOffset = Offset / Scale;
483 unsigned Mask = (1 << NumBits) - 1;
485 if ((unsigned)Offset <= Mask * Scale) {
486 // Replace the FrameIndex with the frame register (e.g., sp).
487 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
488 ImmOp.ChangeToImmediate(ImmedOffset);
490 // If we're using a register where sp was stored, convert the instruction
491 // to the non-SP version.
492 unsigned NewOpc = convertToNonSPOpcode(Opcode);
493 if (NewOpc != Opcode && FrameReg != ARM::SP)
494 MI.setDesc(TII.get(NewOpc));
500 Mask = (1 << NumBits) - 1;
502 // If this is a thumb spill / restore, we will be using a constpool load to
503 // materialize the offset.
504 if (Opcode == ARM::tRestore || Opcode == ARM::tSpill) {
505 ImmOp.ChangeToImmediate(0);
507 // Otherwise, it didn't fit. Pull in what we can to simplify the immed.
508 ImmedOffset = ImmedOffset & Mask;
509 ImmOp.ChangeToImmediate(ImmedOffset);
510 Offset &= ~(Mask * Scale);
518 Thumb1RegisterInfo::resolveFrameIndex(MachineBasicBlock::iterator I,
519 unsigned BaseReg, int64_t Offset) const {
520 MachineInstr &MI = *I;
521 int Off = Offset; // ARM doesn't need the general 64-bit offsets
524 while (!MI.getOperand(i).isFI()) {
526 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
529 Done = rewriteFrameIndex(MI, i, BaseReg, Off, TII);
530 assert (Done && "Unable to resolve frame index!");
533 /// saveScavengerRegister - Spill the register so it can be used by the
534 /// register scavenger. Return true.
536 Thumb1RegisterInfo::saveScavengerRegister(MachineBasicBlock &MBB,
537 MachineBasicBlock::iterator I,
538 MachineBasicBlock::iterator &UseMI,
539 const TargetRegisterClass *RC,
540 unsigned Reg) const {
541 // Thumb1 can't use the emergency spill slot on the stack because
542 // ldr/str immediate offsets must be positive, and if we're referencing
543 // off the frame pointer (if, for example, there are alloca() calls in
544 // the function, the offset will be negative. Use R12 instead since that's
545 // a call clobbered register that we know won't be used in Thumb1 mode.
547 BuildMI(MBB, I, DL, TII.get(ARM::tMOVtgpr2gpr)).
548 addReg(ARM::R12, RegState::Define).addReg(Reg, RegState::Kill);
550 // The UseMI is where we would like to restore the register. If there's
551 // interference with R12 before then, however, we'll need to restore it
552 // before that instead and adjust the UseMI.
554 for (MachineBasicBlock::iterator II = I; !done && II != UseMI ; ++II) {
555 if (II->isDebugValue())
557 // If this instruction affects R12, adjust our restore point.
558 for (unsigned i = 0, e = II->getNumOperands(); i != e; ++i) {
559 const MachineOperand &MO = II->getOperand(i);
560 if (!MO.isReg() || MO.isUndef() || !MO.getReg() ||
561 TargetRegisterInfo::isVirtualRegister(MO.getReg()))
563 if (MO.getReg() == ARM::R12) {
570 // Restore the register from R12
571 BuildMI(MBB, UseMI, DL, TII.get(ARM::tMOVgpr2tgpr)).
572 addReg(Reg, RegState::Define).addReg(ARM::R12, RegState::Kill);
578 Thumb1RegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
579 int SPAdj, RegScavenger *RS) const {
582 MachineInstr &MI = *II;
583 MachineBasicBlock &MBB = *MI.getParent();
584 MachineFunction &MF = *MBB.getParent();
585 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
586 DebugLoc dl = MI.getDebugLoc();
588 while (!MI.getOperand(i).isFI()) {
590 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
593 unsigned FrameReg = ARM::SP;
594 int FrameIndex = MI.getOperand(i).getIndex();
595 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
596 MF.getFrameInfo()->getStackSize() + SPAdj;
598 if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
599 Offset -= AFI->getGPRCalleeSavedArea1Offset();
600 else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
601 Offset -= AFI->getGPRCalleeSavedArea2Offset();
602 else if (MF.getFrameInfo()->hasVarSizedObjects()) {
603 assert(SPAdj == 0 && MF.getTarget().getFrameInfo()->hasFP(MF) &&
605 // There are alloca()'s in this function, must reference off the frame
606 // pointer or base pointer instead.
607 if (!hasBasePointer(MF)) {
608 FrameReg = getFrameRegister(MF);
609 Offset -= AFI->getFramePtrSpillOffset();
614 // Special handling of dbg_value instructions.
615 if (MI.isDebugValue()) {
616 MI.getOperand(i). ChangeToRegister(FrameReg, false /*isDef*/);
617 MI.getOperand(i+1).ChangeToImmediate(Offset);
621 // Modify MI as necessary to handle as much of 'Offset' as possible
622 assert(AFI->isThumbFunction() &&
623 "This eliminateFrameIndex only supports Thumb1!");
624 if (rewriteFrameIndex(MI, i, FrameReg, Offset, TII))
627 // If we get here, the immediate doesn't fit into the instruction. We folded
628 // as much as possible above, handle the rest, providing a register that is
630 assert(Offset && "This code isn't needed if offset already handled!");
632 unsigned Opcode = MI.getOpcode();
633 const TargetInstrDesc &Desc = MI.getDesc();
635 // Remove predicate first.
636 int PIdx = MI.findFirstPredOperandIdx();
638 removeOperands(MI, PIdx);
640 if (Desc.mayLoad()) {
641 // Use the destination register to materialize sp + offset.
642 unsigned TmpReg = MI.getOperand(0).getReg();
644 if (Opcode == ARM::tRestore) {
645 if (FrameReg == ARM::SP)
646 emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg,
647 Offset, false, TII, *this, dl);
649 emitLoadConstPool(MBB, II, dl, TmpReg, 0, Offset);
653 emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII,
657 MI.setDesc(TII.get(ARM::tLDRr));
658 MI.getOperand(i).ChangeToRegister(TmpReg, false, false, true);
660 // Use [reg, reg] addrmode.
661 MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
662 } else if (Desc.mayStore()) {
663 VReg = MF.getRegInfo().createVirtualRegister(ARM::tGPRRegisterClass);
666 if (Opcode == ARM::tSpill) {
667 if (FrameReg == ARM::SP)
668 emitThumbRegPlusImmInReg(MBB, II, VReg, FrameReg,
669 Offset, false, TII, *this, dl);
671 emitLoadConstPool(MBB, II, dl, VReg, 0, Offset);
675 emitThumbRegPlusImmediate(MBB, II, VReg, FrameReg, Offset, TII,
677 MI.setDesc(TII.get(ARM::tSTRr));
678 MI.getOperand(i).ChangeToRegister(VReg, false, false, true);
679 if (UseRR) // Use [reg, reg] addrmode.
680 MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
682 assert(false && "Unexpected opcode!");
685 // Add predicate back if it's needed.
686 if (MI.getDesc().isPredicable()) {
687 MachineInstrBuilder MIB(&MI);