1 //===- ARMBaseRegisterInfo.cpp - ARM 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 base ARM implementation of TargetRegisterInfo class.
12 //===----------------------------------------------------------------------===//
15 #include "ARMAddressingModes.h"
16 #include "ARMBaseInstrInfo.h"
17 #include "ARMBaseRegisterInfo.h"
18 #include "ARMInstrInfo.h"
19 #include "ARMMachineFunctionInfo.h"
20 #include "ARMSubtarget.h"
21 #include "llvm/Constants.h"
22 #include "llvm/DerivedTypes.h"
23 #include "llvm/Function.h"
24 #include "llvm/LLVMContext.h"
25 #include "llvm/CodeGen/MachineConstantPool.h"
26 #include "llvm/CodeGen/MachineFrameInfo.h"
27 #include "llvm/CodeGen/MachineFunction.h"
28 #include "llvm/CodeGen/MachineInstrBuilder.h"
29 #include "llvm/CodeGen/MachineLocation.h"
30 #include "llvm/CodeGen/MachineRegisterInfo.h"
31 #include "llvm/CodeGen/RegisterScavenging.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/raw_ostream.h"
35 #include "llvm/Target/TargetFrameInfo.h"
36 #include "llvm/Target/TargetMachine.h"
37 #include "llvm/Target/TargetOptions.h"
38 #include "llvm/ADT/BitVector.h"
39 #include "llvm/ADT/SmallVector.h"
40 #include "llvm/Support/CommandLine.h"
44 ReuseFrameIndexVals("arm-reuse-frame-index-vals", cl::Hidden, cl::init(true),
45 cl::desc("Reuse repeated frame index values"));
50 unsigned ARMBaseRegisterInfo::getRegisterNumbering(unsigned RegEnum,
58 llvm_unreachable("Unknown ARM register!");
59 case R0: case D0: case Q0: return 0;
60 case R1: case D1: case Q1: return 1;
61 case R2: case D2: case Q2: return 2;
62 case R3: case D3: case Q3: return 3;
63 case R4: case D4: case Q4: return 4;
64 case R5: case D5: case Q5: return 5;
65 case R6: case D6: case Q6: return 6;
66 case R7: case D7: case Q7: return 7;
67 case R8: case D8: case Q8: return 8;
68 case R9: case D9: case Q9: return 9;
69 case R10: case D10: case Q10: return 10;
70 case R11: case D11: case Q11: return 11;
71 case R12: case D12: case Q12: return 12;
72 case SP: case D13: case Q13: return 13;
73 case LR: case D14: case Q14: return 14;
74 case PC: case D15: case Q15: return 15;
93 case S0: case S1: case S2: case S3:
94 case S4: case S5: case S6: case S7:
95 case S8: case S9: case S10: case S11:
96 case S12: case S13: case S14: case S15:
97 case S16: case S17: case S18: case S19:
98 case S20: case S21: case S22: case S23:
99 case S24: case S25: case S26: case S27:
100 case S28: case S29: case S30: case S31: {
104 default: return 0; // Avoid compile time warning.
142 ARMBaseRegisterInfo::ARMBaseRegisterInfo(const ARMBaseInstrInfo &tii,
143 const ARMSubtarget &sti)
144 : ARMGenRegisterInfo(ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP),
146 FramePtr((STI.isTargetDarwin() || STI.isThumb()) ? ARM::R7 : ARM::R11) {
150 ARMBaseRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
151 static const unsigned CalleeSavedRegs[] = {
152 ARM::LR, ARM::R11, ARM::R10, ARM::R9, ARM::R8,
153 ARM::R7, ARM::R6, ARM::R5, ARM::R4,
155 ARM::D15, ARM::D14, ARM::D13, ARM::D12,
156 ARM::D11, ARM::D10, ARM::D9, ARM::D8,
160 static const unsigned DarwinCalleeSavedRegs[] = {
161 // Darwin ABI deviates from ARM standard ABI. R9 is not a callee-saved
163 ARM::LR, ARM::R7, ARM::R6, ARM::R5, ARM::R4,
164 ARM::R11, ARM::R10, ARM::R8,
166 ARM::D15, ARM::D14, ARM::D13, ARM::D12,
167 ARM::D11, ARM::D10, ARM::D9, ARM::D8,
170 return STI.isTargetDarwin() ? DarwinCalleeSavedRegs : CalleeSavedRegs;
173 const TargetRegisterClass* const *
174 ARMBaseRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
175 static const TargetRegisterClass * const CalleeSavedRegClasses[] = {
176 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
177 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
178 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
180 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
181 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
185 static const TargetRegisterClass * const ThumbCalleeSavedRegClasses[] = {
186 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
187 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::tGPRRegClass,
188 &ARM::tGPRRegClass,&ARM::tGPRRegClass,&ARM::tGPRRegClass,
190 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
191 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
195 static const TargetRegisterClass * const DarwinCalleeSavedRegClasses[] = {
196 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
197 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
198 &ARM::GPRRegClass, &ARM::GPRRegClass,
200 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
201 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
205 static const TargetRegisterClass * const DarwinThumbCalleeSavedRegClasses[] ={
206 &ARM::GPRRegClass, &ARM::tGPRRegClass, &ARM::tGPRRegClass,
207 &ARM::tGPRRegClass, &ARM::tGPRRegClass, &ARM::GPRRegClass,
208 &ARM::GPRRegClass, &ARM::GPRRegClass,
210 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
211 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
215 if (STI.isThumb1Only()) {
216 return STI.isTargetDarwin()
217 ? DarwinThumbCalleeSavedRegClasses : ThumbCalleeSavedRegClasses;
219 return STI.isTargetDarwin()
220 ? DarwinCalleeSavedRegClasses : CalleeSavedRegClasses;
223 BitVector ARMBaseRegisterInfo::
224 getReservedRegs(const MachineFunction &MF) const {
225 // FIXME: avoid re-calculating this everytime.
226 BitVector Reserved(getNumRegs());
227 Reserved.set(ARM::SP);
228 Reserved.set(ARM::PC);
229 if (STI.isTargetDarwin() || hasFP(MF))
230 Reserved.set(FramePtr);
231 // Some targets reserve R9.
232 if (STI.isR9Reserved())
233 Reserved.set(ARM::R9);
237 bool ARMBaseRegisterInfo::isReservedReg(const MachineFunction &MF,
238 unsigned Reg) const {
246 if (FramePtr == Reg && (STI.isTargetDarwin() || hasFP(MF)))
250 return STI.isR9Reserved();
256 const TargetRegisterClass *
257 ARMBaseRegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A,
258 const TargetRegisterClass *B,
259 unsigned SubIdx) const {
267 if (A->getSize() == 8) {
268 if (B == &ARM::SPR_8RegClass)
269 return &ARM::DPR_8RegClass;
270 assert(B == &ARM::SPRRegClass && "Expecting SPR register class!");
271 if (A == &ARM::DPR_8RegClass)
273 return &ARM::DPR_VFP2RegClass;
276 assert(A->getSize() == 16 && "Expecting a Q register class!");
277 if (B == &ARM::SPR_8RegClass)
278 return &ARM::QPR_8RegClass;
279 return &ARM::QPR_VFP2RegClass;
283 if (B == &ARM::DPR_VFP2RegClass)
284 return &ARM::QPR_VFP2RegClass;
285 if (B == &ARM::DPR_8RegClass)
286 return &ARM::QPR_8RegClass;
292 const TargetRegisterClass *
293 ARMBaseRegisterInfo::getPointerRegClass(unsigned Kind) const {
294 return ARM::GPRRegisterClass;
297 /// getAllocationOrder - Returns the register allocation order for a specified
298 /// register class in the form of a pair of TargetRegisterClass iterators.
299 std::pair<TargetRegisterClass::iterator,TargetRegisterClass::iterator>
300 ARMBaseRegisterInfo::getAllocationOrder(const TargetRegisterClass *RC,
301 unsigned HintType, unsigned HintReg,
302 const MachineFunction &MF) const {
303 // Alternative register allocation orders when favoring even / odd registers
304 // of register pairs.
306 // No FP, R9 is available.
307 static const unsigned GPREven1[] = {
308 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8, ARM::R10,
309 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7,
312 static const unsigned GPROdd1[] = {
313 ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R9, ARM::R11,
314 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6,
318 // FP is R7, R9 is available.
319 static const unsigned GPREven2[] = {
320 ARM::R0, ARM::R2, ARM::R4, ARM::R8, ARM::R10,
321 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6,
324 static const unsigned GPROdd2[] = {
325 ARM::R1, ARM::R3, ARM::R5, ARM::R9, ARM::R11,
326 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6,
330 // FP is R11, R9 is available.
331 static const unsigned GPREven3[] = {
332 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8,
333 ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7,
336 static const unsigned GPROdd3[] = {
337 ARM::R1, ARM::R3, ARM::R5, ARM::R6, ARM::R9,
338 ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R7,
342 // No FP, R9 is not available.
343 static const unsigned GPREven4[] = {
344 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R10,
345 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8,
348 static const unsigned GPROdd4[] = {
349 ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R11,
350 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8,
354 // FP is R7, R9 is not available.
355 static const unsigned GPREven5[] = {
356 ARM::R0, ARM::R2, ARM::R4, ARM::R10,
357 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6, ARM::R8,
360 static const unsigned GPROdd5[] = {
361 ARM::R1, ARM::R3, ARM::R5, ARM::R11,
362 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8,
366 // FP is R11, R9 is not available.
367 static const unsigned GPREven6[] = {
368 ARM::R0, ARM::R2, ARM::R4, ARM::R6,
369 ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8
371 static const unsigned GPROdd6[] = {
372 ARM::R1, ARM::R3, ARM::R5, ARM::R7,
373 ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8
377 if (HintType == ARMRI::RegPairEven) {
378 if (isPhysicalRegister(HintReg) && getRegisterPairEven(HintReg, MF) == 0)
379 // It's no longer possible to fulfill this hint. Return the default
381 return std::make_pair(RC->allocation_order_begin(MF),
382 RC->allocation_order_end(MF));
384 if (!STI.isTargetDarwin() && !hasFP(MF)) {
385 if (!STI.isR9Reserved())
386 return std::make_pair(GPREven1,
387 GPREven1 + (sizeof(GPREven1)/sizeof(unsigned)));
389 return std::make_pair(GPREven4,
390 GPREven4 + (sizeof(GPREven4)/sizeof(unsigned)));
391 } else if (FramePtr == ARM::R7) {
392 if (!STI.isR9Reserved())
393 return std::make_pair(GPREven2,
394 GPREven2 + (sizeof(GPREven2)/sizeof(unsigned)));
396 return std::make_pair(GPREven5,
397 GPREven5 + (sizeof(GPREven5)/sizeof(unsigned)));
398 } else { // FramePtr == ARM::R11
399 if (!STI.isR9Reserved())
400 return std::make_pair(GPREven3,
401 GPREven3 + (sizeof(GPREven3)/sizeof(unsigned)));
403 return std::make_pair(GPREven6,
404 GPREven6 + (sizeof(GPREven6)/sizeof(unsigned)));
406 } else if (HintType == ARMRI::RegPairOdd) {
407 if (isPhysicalRegister(HintReg) && getRegisterPairOdd(HintReg, MF) == 0)
408 // It's no longer possible to fulfill this hint. Return the default
410 return std::make_pair(RC->allocation_order_begin(MF),
411 RC->allocation_order_end(MF));
413 if (!STI.isTargetDarwin() && !hasFP(MF)) {
414 if (!STI.isR9Reserved())
415 return std::make_pair(GPROdd1,
416 GPROdd1 + (sizeof(GPROdd1)/sizeof(unsigned)));
418 return std::make_pair(GPROdd4,
419 GPROdd4 + (sizeof(GPROdd4)/sizeof(unsigned)));
420 } else if (FramePtr == ARM::R7) {
421 if (!STI.isR9Reserved())
422 return std::make_pair(GPROdd2,
423 GPROdd2 + (sizeof(GPROdd2)/sizeof(unsigned)));
425 return std::make_pair(GPROdd5,
426 GPROdd5 + (sizeof(GPROdd5)/sizeof(unsigned)));
427 } else { // FramePtr == ARM::R11
428 if (!STI.isR9Reserved())
429 return std::make_pair(GPROdd3,
430 GPROdd3 + (sizeof(GPROdd3)/sizeof(unsigned)));
432 return std::make_pair(GPROdd6,
433 GPROdd6 + (sizeof(GPROdd6)/sizeof(unsigned)));
436 return std::make_pair(RC->allocation_order_begin(MF),
437 RC->allocation_order_end(MF));
440 /// ResolveRegAllocHint - Resolves the specified register allocation hint
441 /// to a physical register. Returns the physical register if it is successful.
443 ARMBaseRegisterInfo::ResolveRegAllocHint(unsigned Type, unsigned Reg,
444 const MachineFunction &MF) const {
445 if (Reg == 0 || !isPhysicalRegister(Reg))
449 else if (Type == (unsigned)ARMRI::RegPairOdd)
451 return getRegisterPairOdd(Reg, MF);
452 else if (Type == (unsigned)ARMRI::RegPairEven)
454 return getRegisterPairEven(Reg, MF);
459 ARMBaseRegisterInfo::UpdateRegAllocHint(unsigned Reg, unsigned NewReg,
460 MachineFunction &MF) const {
461 MachineRegisterInfo *MRI = &MF.getRegInfo();
462 std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(Reg);
463 if ((Hint.first == (unsigned)ARMRI::RegPairOdd ||
464 Hint.first == (unsigned)ARMRI::RegPairEven) &&
465 Hint.second && TargetRegisterInfo::isVirtualRegister(Hint.second)) {
466 // If 'Reg' is one of the even / odd register pair and it's now changed
467 // (e.g. coalesced) into a different register. The other register of the
468 // pair allocation hint must be updated to reflect the relationship
470 unsigned OtherReg = Hint.second;
471 Hint = MRI->getRegAllocationHint(OtherReg);
472 if (Hint.second == Reg)
473 // Make sure the pair has not already divorced.
474 MRI->setRegAllocationHint(OtherReg, Hint.first, NewReg);
478 /// hasFP - Return true if the specified function should have a dedicated frame
479 /// pointer register. This is true if the function has variable sized allocas
480 /// or if frame pointer elimination is disabled.
482 bool ARMBaseRegisterInfo::hasFP(const MachineFunction &MF) const {
483 const MachineFrameInfo *MFI = MF.getFrameInfo();
484 return ((DisableFramePointerElim(MF) && MFI->hasCalls())||
485 needsStackRealignment(MF) ||
486 MFI->hasVarSizedObjects() ||
487 MFI->isFrameAddressTaken());
490 bool ARMBaseRegisterInfo::canRealignStack(const MachineFunction &MF) const {
491 const MachineFrameInfo *MFI = MF.getFrameInfo();
492 const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
493 return (RealignStack &&
494 !AFI->isThumb1OnlyFunction() &&
495 !MFI->hasVarSizedObjects());
498 bool ARMBaseRegisterInfo::
499 needsStackRealignment(const MachineFunction &MF) const {
500 const MachineFrameInfo *MFI = MF.getFrameInfo();
501 const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
502 unsigned StackAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
503 return (RealignStack &&
504 !AFI->isThumb1OnlyFunction() &&
505 (MFI->getMaxAlignment() > StackAlign) &&
506 !MFI->hasVarSizedObjects());
509 bool ARMBaseRegisterInfo::
510 cannotEliminateFrame(const MachineFunction &MF) const {
511 const MachineFrameInfo *MFI = MF.getFrameInfo();
512 if (DisableFramePointerElim(MF) && MFI->hasCalls())
514 return MFI->hasVarSizedObjects() || MFI->isFrameAddressTaken()
515 || needsStackRealignment(MF);
518 /// estimateStackSize - Estimate and return the size of the frame.
519 static unsigned estimateStackSize(MachineFunction &MF) {
520 const MachineFrameInfo *FFI = MF.getFrameInfo();
522 for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) {
523 int FixedOff = -FFI->getObjectOffset(i);
524 if (FixedOff > Offset) Offset = FixedOff;
526 for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
527 if (FFI->isDeadObjectIndex(i))
529 Offset += FFI->getObjectSize(i);
530 unsigned Align = FFI->getObjectAlignment(i);
531 // Adjust to alignment boundary
532 Offset = (Offset+Align-1)/Align*Align;
534 return (unsigned)Offset;
537 /// estimateRSStackSizeLimit - Look at each instruction that references stack
538 /// frames and return the stack size limit beyond which some of these
539 /// instructions will require a scratch register during their expansion later.
541 ARMBaseRegisterInfo::estimateRSStackSizeLimit(MachineFunction &MF) const {
542 unsigned Limit = (1 << 12) - 1;
543 for (MachineFunction::iterator BB = MF.begin(),E = MF.end(); BB != E; ++BB) {
544 for (MachineBasicBlock::iterator I = BB->begin(), E = BB->end();
546 for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
547 if (!I->getOperand(i).isFI()) continue;
549 const TargetInstrDesc &Desc = TII.get(I->getOpcode());
550 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
551 if (AddrMode == ARMII::AddrMode3 ||
552 AddrMode == ARMII::AddrModeT2_i8)
555 if (AddrMode == ARMII::AddrMode5 ||
556 AddrMode == ARMII::AddrModeT2_i8s4)
557 Limit = std::min(Limit, ((1U << 8) - 1) * 4);
559 if (AddrMode == ARMII::AddrModeT2_i12 && hasFP(MF))
560 // When the stack offset is negative, we will end up using
561 // the i8 instructions instead.
564 if (AddrMode == ARMII::AddrMode6)
566 break; // At most one FI per instruction
575 ARMBaseRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
576 RegScavenger *RS) const {
577 // This tells PEI to spill the FP as if it is any other callee-save register
578 // to take advantage the eliminateFrameIndex machinery. This also ensures it
579 // is spilled in the order specified by getCalleeSavedRegs() to make it easier
580 // to combine multiple loads / stores.
581 bool CanEliminateFrame = true;
582 bool CS1Spilled = false;
583 bool LRSpilled = false;
584 unsigned NumGPRSpills = 0;
585 SmallVector<unsigned, 4> UnspilledCS1GPRs;
586 SmallVector<unsigned, 4> UnspilledCS2GPRs;
587 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
589 // Spill R4 if Thumb2 function requires stack realignment - it will be used as
591 // FIXME: It will be better just to find spare register here.
592 if (needsStackRealignment(MF) &&
593 AFI->isThumb2Function())
594 MF.getRegInfo().setPhysRegUsed(ARM::R4);
596 // Spill LR if Thumb1 function uses variable length argument lists.
597 if (AFI->isThumb1OnlyFunction() && AFI->getVarArgsRegSaveSize() > 0)
598 MF.getRegInfo().setPhysRegUsed(ARM::LR);
600 // Don't spill FP if the frame can be eliminated. This is determined
601 // by scanning the callee-save registers to see if any is used.
602 const unsigned *CSRegs = getCalleeSavedRegs();
603 const TargetRegisterClass* const *CSRegClasses = getCalleeSavedRegClasses();
604 for (unsigned i = 0; CSRegs[i]; ++i) {
605 unsigned Reg = CSRegs[i];
606 bool Spilled = false;
607 if (MF.getRegInfo().isPhysRegUsed(Reg)) {
608 AFI->setCSRegisterIsSpilled(Reg);
610 CanEliminateFrame = false;
612 // Check alias registers too.
613 for (const unsigned *Aliases = getAliasSet(Reg); *Aliases; ++Aliases) {
614 if (MF.getRegInfo().isPhysRegUsed(*Aliases)) {
616 CanEliminateFrame = false;
621 if (CSRegClasses[i] == ARM::GPRRegisterClass ||
622 CSRegClasses[i] == ARM::tGPRRegisterClass) {
626 if (!STI.isTargetDarwin()) {
633 // Keep track if LR and any of R4, R5, R6, and R7 is spilled.
648 if (!STI.isTargetDarwin()) {
649 UnspilledCS1GPRs.push_back(Reg);
659 UnspilledCS1GPRs.push_back(Reg);
662 UnspilledCS2GPRs.push_back(Reg);
669 bool ForceLRSpill = false;
670 if (!LRSpilled && AFI->isThumb1OnlyFunction()) {
671 unsigned FnSize = TII.GetFunctionSizeInBytes(MF);
672 // Force LR to be spilled if the Thumb function size is > 2048. This enables
673 // use of BL to implement far jump. If it turns out that it's not needed
674 // then the branch fix up path will undo it.
675 if (FnSize >= (1 << 11)) {
676 CanEliminateFrame = false;
681 // If any of the stack slot references may be out of range of an immediate
682 // offset, make sure a register (or a spill slot) is available for the
683 // register scavenger. Note that if we're indexing off the frame pointer, the
684 // effective stack size is 4 bytes larger since the FP points to the stack
685 // slot of the previous FP.
686 bool BigStack = RS &&
687 estimateStackSize(MF) + (hasFP(MF) ? 4 : 0) >= estimateRSStackSizeLimit(MF);
689 bool ExtraCSSpill = false;
690 if (BigStack || !CanEliminateFrame || cannotEliminateFrame(MF)) {
691 AFI->setHasStackFrame(true);
693 // If LR is not spilled, but at least one of R4, R5, R6, and R7 is spilled.
694 // Spill LR as well so we can fold BX_RET to the registers restore (LDM).
695 if (!LRSpilled && CS1Spilled) {
696 MF.getRegInfo().setPhysRegUsed(ARM::LR);
697 AFI->setCSRegisterIsSpilled(ARM::LR);
699 UnspilledCS1GPRs.erase(std::find(UnspilledCS1GPRs.begin(),
700 UnspilledCS1GPRs.end(), (unsigned)ARM::LR));
701 ForceLRSpill = false;
705 // Darwin ABI requires FP to point to the stack slot that contains the
707 if (STI.isTargetDarwin() || hasFP(MF)) {
708 MF.getRegInfo().setPhysRegUsed(FramePtr);
712 // If stack and double are 8-byte aligned and we are spilling an odd number
713 // of GPRs. Spill one extra callee save GPR so we won't have to pad between
714 // the integer and double callee save areas.
715 unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
716 if (TargetAlign == 8 && (NumGPRSpills & 1)) {
717 if (CS1Spilled && !UnspilledCS1GPRs.empty()) {
718 for (unsigned i = 0, e = UnspilledCS1GPRs.size(); i != e; ++i) {
719 unsigned Reg = UnspilledCS1GPRs[i];
720 // Don't spill high register if the function is thumb1
721 if (!AFI->isThumb1OnlyFunction() ||
722 isARMLowRegister(Reg) || Reg == ARM::LR) {
723 MF.getRegInfo().setPhysRegUsed(Reg);
724 AFI->setCSRegisterIsSpilled(Reg);
725 if (!isReservedReg(MF, Reg))
730 } else if (!UnspilledCS2GPRs.empty() &&
731 !AFI->isThumb1OnlyFunction()) {
732 unsigned Reg = UnspilledCS2GPRs.front();
733 MF.getRegInfo().setPhysRegUsed(Reg);
734 AFI->setCSRegisterIsSpilled(Reg);
735 if (!isReservedReg(MF, Reg))
740 // Estimate if we might need to scavenge a register at some point in order
741 // to materialize a stack offset. If so, either spill one additional
742 // callee-saved register or reserve a special spill slot to facilitate
743 // register scavenging. Thumb1 needs a spill slot for stack pointer
744 // adjustments also, even when the frame itself is small.
745 if (BigStack && !ExtraCSSpill) {
746 // If any non-reserved CS register isn't spilled, just spill one or two
747 // extra. That should take care of it!
748 unsigned NumExtras = TargetAlign / 4;
749 SmallVector<unsigned, 2> Extras;
750 while (NumExtras && !UnspilledCS1GPRs.empty()) {
751 unsigned Reg = UnspilledCS1GPRs.back();
752 UnspilledCS1GPRs.pop_back();
753 if (!isReservedReg(MF, Reg)) {
754 Extras.push_back(Reg);
758 // For non-Thumb1 functions, also check for hi-reg CS registers
759 if (!AFI->isThumb1OnlyFunction()) {
760 while (NumExtras && !UnspilledCS2GPRs.empty()) {
761 unsigned Reg = UnspilledCS2GPRs.back();
762 UnspilledCS2GPRs.pop_back();
763 if (!isReservedReg(MF, Reg)) {
764 Extras.push_back(Reg);
769 if (Extras.size() && NumExtras == 0) {
770 for (unsigned i = 0, e = Extras.size(); i != e; ++i) {
771 MF.getRegInfo().setPhysRegUsed(Extras[i]);
772 AFI->setCSRegisterIsSpilled(Extras[i]);
774 } else if (!AFI->isThumb1OnlyFunction()) {
775 // note: Thumb1 functions spill to R12, not the stack. Reserve a slot
776 // closest to SP or frame pointer.
777 const TargetRegisterClass *RC = ARM::GPRRegisterClass;
778 MachineFrameInfo *MFI = MF.getFrameInfo();
779 RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
787 MF.getRegInfo().setPhysRegUsed(ARM::LR);
788 AFI->setCSRegisterIsSpilled(ARM::LR);
789 AFI->setLRIsSpilledForFarJump(true);
793 unsigned ARMBaseRegisterInfo::getRARegister() const {
798 ARMBaseRegisterInfo::getFrameRegister(const MachineFunction &MF) const {
799 if (STI.isTargetDarwin() || hasFP(MF))
805 ARMBaseRegisterInfo::getFrameIndexReference(const MachineFunction &MF, int FI,
806 unsigned &FrameReg) const {
807 const MachineFrameInfo *MFI = MF.getFrameInfo();
808 const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
809 int Offset = MFI->getObjectOffset(FI) + MFI->getStackSize();
810 bool isFixed = MFI->isFixedObjectIndex(FI);
813 if (AFI->isGPRCalleeSavedArea1Frame(FI))
814 Offset -= AFI->getGPRCalleeSavedArea1Offset();
815 else if (AFI->isGPRCalleeSavedArea2Frame(FI))
816 Offset -= AFI->getGPRCalleeSavedArea2Offset();
817 else if (AFI->isDPRCalleeSavedAreaFrame(FI))
818 Offset -= AFI->getDPRCalleeSavedAreaOffset();
819 else if (needsStackRealignment(MF)) {
820 // When dynamically realigning the stack, use the frame pointer for
821 // parameters, and the stack pointer for locals.
822 assert (hasFP(MF) && "dynamic stack realignment without a FP!");
824 FrameReg = getFrameRegister(MF);
825 Offset -= AFI->getFramePtrSpillOffset();
827 } else if (hasFP(MF) && AFI->hasStackFrame()) {
828 if (isFixed || MFI->hasVarSizedObjects()) {
829 // Use frame pointer to reference fixed objects unless this is a
830 // frameless function.
831 FrameReg = getFrameRegister(MF);
832 Offset -= AFI->getFramePtrSpillOffset();
833 } else if (AFI->isThumb2Function()) {
834 // In Thumb2 mode, the negative offset is very limited.
835 int FPOffset = Offset - AFI->getFramePtrSpillOffset();
836 if (FPOffset >= -255 && FPOffset < 0) {
837 FrameReg = getFrameRegister(MF);
847 ARMBaseRegisterInfo::getFrameIndexOffset(const MachineFunction &MF,
850 return getFrameIndexReference(MF, FI, FrameReg);
853 unsigned ARMBaseRegisterInfo::getEHExceptionRegister() const {
854 llvm_unreachable("What is the exception register");
858 unsigned ARMBaseRegisterInfo::getEHHandlerRegister() const {
859 llvm_unreachable("What is the exception handler register");
863 int ARMBaseRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
864 return ARMGenRegisterInfo::getDwarfRegNumFull(RegNum, 0);
867 unsigned ARMBaseRegisterInfo::getRegisterPairEven(unsigned Reg,
868 const MachineFunction &MF) const {
871 // Return 0 if either register of the pair is a special register.
880 return isReservedReg(MF, ARM::R7) ? 0 : ARM::R6;
882 return isReservedReg(MF, ARM::R9) ? 0 :ARM::R8;
884 return isReservedReg(MF, ARM::R11) ? 0 : ARM::R10;
956 unsigned ARMBaseRegisterInfo::getRegisterPairOdd(unsigned Reg,
957 const MachineFunction &MF) const {
960 // Return 0 if either register of the pair is a special register.
969 return isReservedReg(MF, ARM::R7) ? 0 : ARM::R7;
971 return isReservedReg(MF, ARM::R9) ? 0 :ARM::R9;
973 return isReservedReg(MF, ARM::R11) ? 0 : ARM::R11;
1045 /// emitLoadConstPool - Emits a load from constpool to materialize the
1046 /// specified immediate.
1047 void ARMBaseRegisterInfo::
1048 emitLoadConstPool(MachineBasicBlock &MBB,
1049 MachineBasicBlock::iterator &MBBI,
1051 unsigned DestReg, unsigned SubIdx, int Val,
1052 ARMCC::CondCodes Pred,
1053 unsigned PredReg) const {
1054 MachineFunction &MF = *MBB.getParent();
1055 MachineConstantPool *ConstantPool = MF.getConstantPool();
1057 ConstantInt::get(Type::getInt32Ty(MF.getFunction()->getContext()), Val);
1058 unsigned Idx = ConstantPool->getConstantPoolIndex(C, 4);
1060 BuildMI(MBB, MBBI, dl, TII.get(ARM::LDRcp))
1061 .addReg(DestReg, getDefRegState(true), SubIdx)
1062 .addConstantPoolIndex(Idx)
1063 .addReg(0).addImm(0).addImm(Pred).addReg(PredReg);
1066 bool ARMBaseRegisterInfo::
1067 requiresRegisterScavenging(const MachineFunction &MF) const {
1071 bool ARMBaseRegisterInfo::
1072 requiresFrameIndexScavenging(const MachineFunction &MF) const {
1076 // hasReservedCallFrame - Under normal circumstances, when a frame pointer is
1077 // not required, we reserve argument space for call sites in the function
1078 // immediately on entry to the current function. This eliminates the need for
1079 // add/sub sp brackets around call sites. Returns true if the call frame is
1080 // included as part of the stack frame.
1081 bool ARMBaseRegisterInfo::
1082 hasReservedCallFrame(MachineFunction &MF) const {
1083 const MachineFrameInfo *FFI = MF.getFrameInfo();
1084 unsigned CFSize = FFI->getMaxCallFrameSize();
1085 // It's not always a good idea to include the call frame as part of the
1086 // stack frame. ARM (especially Thumb) has small immediate offset to
1087 // address the stack frame. So a large call frame can cause poor codegen
1088 // and may even makes it impossible to scavenge a register.
1089 if (CFSize >= ((1 << 12) - 1) / 2) // Half of imm12
1092 return !MF.getFrameInfo()->hasVarSizedObjects();
1095 // canSimplifyCallFramePseudos - If there is a reserved call frame, the
1096 // call frame pseudos can be simplified. Unlike most targets, having a FP
1097 // is not sufficient here since we still may reference some objects via SP
1098 // even when FP is available in Thumb2 mode.
1099 bool ARMBaseRegisterInfo::
1100 canSimplifyCallFramePseudos(MachineFunction &MF) const {
1101 return hasReservedCallFrame(MF) || MF.getFrameInfo()->hasVarSizedObjects();
1105 emitSPUpdate(bool isARM,
1106 MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
1107 DebugLoc dl, const ARMBaseInstrInfo &TII,
1109 ARMCC::CondCodes Pred = ARMCC::AL, unsigned PredReg = 0) {
1111 emitARMRegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
1112 Pred, PredReg, TII);
1114 emitT2RegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
1115 Pred, PredReg, TII);
1119 void ARMBaseRegisterInfo::
1120 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
1121 MachineBasicBlock::iterator I) const {
1122 if (!hasReservedCallFrame(MF)) {
1123 // If we have alloca, convert as follows:
1124 // ADJCALLSTACKDOWN -> sub, sp, sp, amount
1125 // ADJCALLSTACKUP -> add, sp, sp, amount
1126 MachineInstr *Old = I;
1127 DebugLoc dl = Old->getDebugLoc();
1128 unsigned Amount = Old->getOperand(0).getImm();
1130 // We need to keep the stack aligned properly. To do this, we round the
1131 // amount of space needed for the outgoing arguments up to the next
1132 // alignment boundary.
1133 unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
1134 Amount = (Amount+Align-1)/Align*Align;
1136 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1137 assert(!AFI->isThumb1OnlyFunction() &&
1138 "This eliminateCallFramePseudoInstr does not support Thumb1!");
1139 bool isARM = !AFI->isThumbFunction();
1141 // Replace the pseudo instruction with a new instruction...
1142 unsigned Opc = Old->getOpcode();
1143 int PIdx = Old->findFirstPredOperandIdx();
1144 ARMCC::CondCodes Pred = (PIdx == -1)
1145 ? ARMCC::AL : (ARMCC::CondCodes)Old->getOperand(PIdx).getImm();
1146 if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) {
1147 // Note: PredReg is operand 2 for ADJCALLSTACKDOWN.
1148 unsigned PredReg = Old->getOperand(2).getReg();
1149 emitSPUpdate(isARM, MBB, I, dl, TII, -Amount, Pred, PredReg);
1151 // Note: PredReg is operand 3 for ADJCALLSTACKUP.
1152 unsigned PredReg = Old->getOperand(3).getReg();
1153 assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP);
1154 emitSPUpdate(isARM, MBB, I, dl, TII, Amount, Pred, PredReg);
1162 ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
1163 int SPAdj, FrameIndexValue *Value,
1164 RegScavenger *RS) const {
1166 MachineInstr &MI = *II;
1167 MachineBasicBlock &MBB = *MI.getParent();
1168 MachineFunction &MF = *MBB.getParent();
1169 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1170 assert(!AFI->isThumb1OnlyFunction() &&
1171 "This eliminateFrameIndex does not support Thumb1!");
1173 while (!MI.getOperand(i).isFI()) {
1175 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
1178 int FrameIndex = MI.getOperand(i).getIndex();
1181 int Offset = getFrameIndexReference(MF, FrameIndex, FrameReg);
1182 if (FrameReg != ARM::SP)
1186 // Special handling of dbg_value instructions.
1187 if (MI.isDebugValue()) {
1188 MI.getOperand(i). ChangeToRegister(FrameReg, false /*isDef*/);
1189 MI.getOperand(i+1).ChangeToImmediate(Offset);
1193 // Modify MI as necessary to handle as much of 'Offset' as possible
1195 if (!AFI->isThumbFunction())
1196 Done = rewriteARMFrameIndex(MI, i, FrameReg, Offset, TII);
1198 assert(AFI->isThumb2Function());
1199 Done = rewriteT2FrameIndex(MI, i, FrameReg, Offset, TII);
1204 // If we get here, the immediate doesn't fit into the instruction. We folded
1205 // as much as possible above, handle the rest, providing a register that is
1208 (MI.getDesc().TSFlags & ARMII::AddrModeMask) == ARMII::AddrMode4 ||
1209 (MI.getDesc().TSFlags & ARMII::AddrModeMask) == ARMII::AddrMode6) &&
1210 "This code isn't needed if offset already handled!");
1212 unsigned ScratchReg = 0;
1213 int PIdx = MI.findFirstPredOperandIdx();
1214 ARMCC::CondCodes Pred = (PIdx == -1)
1215 ? ARMCC::AL : (ARMCC::CondCodes)MI.getOperand(PIdx).getImm();
1216 unsigned PredReg = (PIdx == -1) ? 0 : MI.getOperand(PIdx+1).getReg();
1218 // Must be addrmode4/6.
1219 MI.getOperand(i).ChangeToRegister(FrameReg, false, false, false);
1221 ScratchReg = MF.getRegInfo().createVirtualRegister(ARM::GPRRegisterClass);
1223 Value->first = FrameReg; // use the frame register as a kind indicator
1224 Value->second = Offset;
1226 if (!AFI->isThumbFunction())
1227 emitARMRegPlusImmediate(MBB, II, MI.getDebugLoc(), ScratchReg, FrameReg,
1228 Offset, Pred, PredReg, TII);
1230 assert(AFI->isThumb2Function());
1231 emitT2RegPlusImmediate(MBB, II, MI.getDebugLoc(), ScratchReg, FrameReg,
1232 Offset, Pred, PredReg, TII);
1234 MI.getOperand(i).ChangeToRegister(ScratchReg, false, false, true);
1235 if (!ReuseFrameIndexVals)
1241 /// Move iterator past the next bunch of callee save load / store ops for
1242 /// the particular spill area (1: integer area 1, 2: integer area 2,
1243 /// 3: fp area, 0: don't care).
1244 static void movePastCSLoadStoreOps(MachineBasicBlock &MBB,
1245 MachineBasicBlock::iterator &MBBI,
1246 int Opc1, int Opc2, unsigned Area,
1247 const ARMSubtarget &STI) {
1248 while (MBBI != MBB.end() &&
1249 ((MBBI->getOpcode() == Opc1) || (MBBI->getOpcode() == Opc2)) &&
1250 MBBI->getOperand(1).isFI()) {
1253 unsigned Category = 0;
1254 switch (MBBI->getOperand(0).getReg()) {
1255 case ARM::R4: case ARM::R5: case ARM::R6: case ARM::R7:
1259 case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11:
1260 Category = STI.isTargetDarwin() ? 2 : 1;
1262 case ARM::D8: case ARM::D9: case ARM::D10: case ARM::D11:
1263 case ARM::D12: case ARM::D13: case ARM::D14: case ARM::D15:
1270 if (Done || Category != Area)
1278 void ARMBaseRegisterInfo::
1279 emitPrologue(MachineFunction &MF) const {
1280 MachineBasicBlock &MBB = MF.front();
1281 MachineBasicBlock::iterator MBBI = MBB.begin();
1282 MachineFrameInfo *MFI = MF.getFrameInfo();
1283 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1284 assert(!AFI->isThumb1OnlyFunction() &&
1285 "This emitPrologue does not support Thumb1!");
1286 bool isARM = !AFI->isThumbFunction();
1287 unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
1288 unsigned NumBytes = MFI->getStackSize();
1289 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
1290 DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
1292 // Determine the sizes of each callee-save spill areas and record which frame
1293 // belongs to which callee-save spill areas.
1294 unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
1295 int FramePtrSpillFI = 0;
1297 // Allocate the vararg register save area. This is not counted in NumBytes.
1299 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -VARegSaveSize);
1301 if (!AFI->hasStackFrame()) {
1303 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes);
1307 for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
1308 unsigned Reg = CSI[i].getReg();
1309 int FI = CSI[i].getFrameIdx();
1316 if (Reg == FramePtr)
1317 FramePtrSpillFI = FI;
1318 AFI->addGPRCalleeSavedArea1Frame(FI);
1325 if (Reg == FramePtr)
1326 FramePtrSpillFI = FI;
1327 if (STI.isTargetDarwin()) {
1328 AFI->addGPRCalleeSavedArea2Frame(FI);
1331 AFI->addGPRCalleeSavedArea1Frame(FI);
1336 AFI->addDPRCalleeSavedAreaFrame(FI);
1341 // Build the new SUBri to adjust SP for integer callee-save spill area 1.
1342 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS1Size);
1343 movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, ARM::t2STRi12, 1, STI);
1345 // Set FP to point to the stack slot that contains the previous FP.
1346 // For Darwin, FP is R7, which has now been stored in spill area 1.
1347 // Otherwise, if this is not Darwin, all the callee-saved registers go
1348 // into spill area 1, including the FP in R11. In either case, it is
1349 // now safe to emit this assignment.
1350 if (STI.isTargetDarwin() || hasFP(MF)) {
1351 unsigned ADDriOpc = !AFI->isThumbFunction() ? ARM::ADDri : ARM::t2ADDri;
1352 MachineInstrBuilder MIB =
1353 BuildMI(MBB, MBBI, dl, TII.get(ADDriOpc), FramePtr)
1354 .addFrameIndex(FramePtrSpillFI).addImm(0);
1355 AddDefaultCC(AddDefaultPred(MIB));
1358 // Build the new SUBri to adjust SP for integer callee-save spill area 2.
1359 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS2Size);
1361 // Build the new SUBri to adjust SP for FP callee-save spill area.
1362 movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, ARM::t2STRi12, 2, STI);
1363 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -DPRCSSize);
1365 // Determine starting offsets of spill areas.
1366 unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
1367 unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
1368 unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
1369 if (STI.isTargetDarwin() || hasFP(MF))
1370 AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) +
1372 AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
1373 AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
1374 AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
1376 movePastCSLoadStoreOps(MBB, MBBI, ARM::VSTRD, 0, 3, STI);
1377 NumBytes = DPRCSOffset;
1379 // Adjust SP after all the callee-save spills.
1380 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes);
1383 if (STI.isTargetELF() && hasFP(MF)) {
1384 MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
1385 AFI->getFramePtrSpillOffset());
1388 AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
1389 AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
1390 AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
1392 // If we need dynamic stack realignment, do it here.
1393 if (needsStackRealignment(MF)) {
1394 unsigned MaxAlign = MFI->getMaxAlignment();
1395 assert (!AFI->isThumb1OnlyFunction());
1396 if (!AFI->isThumbFunction()) {
1397 // Emit bic sp, sp, MaxAlign
1398 AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl,
1399 TII.get(ARM::BICri), ARM::SP)
1400 .addReg(ARM::SP, RegState::Kill)
1401 .addImm(MaxAlign-1)));
1403 // We cannot use sp as source/dest register here, thus we're emitting the
1404 // following sequence:
1406 // bic r4, r4, MaxAlign
1408 // FIXME: It will be better just to find spare register here.
1409 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2tgpr), ARM::R4)
1410 .addReg(ARM::SP, RegState::Kill);
1411 AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl,
1412 TII.get(ARM::t2BICri), ARM::R4)
1413 .addReg(ARM::R4, RegState::Kill)
1414 .addImm(MaxAlign-1)));
1415 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVtgpr2gpr), ARM::SP)
1416 .addReg(ARM::R4, RegState::Kill);
1421 static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
1422 for (unsigned i = 0; CSRegs[i]; ++i)
1423 if (Reg == CSRegs[i])
1428 static bool isCSRestore(MachineInstr *MI,
1429 const ARMBaseInstrInfo &TII,
1430 const unsigned *CSRegs) {
1431 return ((MI->getOpcode() == (int)ARM::VLDRD ||
1432 MI->getOpcode() == (int)ARM::LDR ||
1433 MI->getOpcode() == (int)ARM::t2LDRi12) &&
1434 MI->getOperand(1).isFI() &&
1435 isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs));
1438 void ARMBaseRegisterInfo::
1439 emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const {
1440 MachineBasicBlock::iterator MBBI = prior(MBB.end());
1441 assert(MBBI->getDesc().isReturn() &&
1442 "Can only insert epilog into returning blocks");
1443 DebugLoc dl = MBBI->getDebugLoc();
1444 MachineFrameInfo *MFI = MF.getFrameInfo();
1445 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1446 assert(!AFI->isThumb1OnlyFunction() &&
1447 "This emitEpilogue does not support Thumb1!");
1448 bool isARM = !AFI->isThumbFunction();
1450 unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
1451 int NumBytes = (int)MFI->getStackSize();
1453 if (!AFI->hasStackFrame()) {
1455 emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
1457 // Unwind MBBI to point to first LDR / VLDRD.
1458 const unsigned *CSRegs = getCalleeSavedRegs();
1459 if (MBBI != MBB.begin()) {
1462 while (MBBI != MBB.begin() && isCSRestore(MBBI, TII, CSRegs));
1463 if (!isCSRestore(MBBI, TII, CSRegs))
1467 // Move SP to start of FP callee save spill area.
1468 NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
1469 AFI->getGPRCalleeSavedArea2Size() +
1470 AFI->getDPRCalleeSavedAreaSize());
1472 // Darwin ABI requires FP to point to the stack slot that contains the
1474 bool HasFP = hasFP(MF);
1475 if ((STI.isTargetDarwin() && NumBytes) || HasFP) {
1476 NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
1477 // Reset SP based on frame pointer only if the stack frame extends beyond
1478 // frame pointer stack slot or target is ELF and the function has FP.
1480 AFI->getGPRCalleeSavedArea2Size() ||
1481 AFI->getDPRCalleeSavedAreaSize() ||
1482 AFI->getDPRCalleeSavedAreaOffset()) {
1485 emitARMRegPlusImmediate(MBB, MBBI, dl, ARM::SP, FramePtr, -NumBytes,
1488 emitT2RegPlusImmediate(MBB, MBBI, dl, ARM::SP, FramePtr, -NumBytes,
1493 BuildMI(MBB, MBBI, dl, TII.get(ARM::MOVr), ARM::SP)
1495 .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
1497 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2gpr), ARM::SP)
1501 } else if (NumBytes)
1502 emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
1504 // Move SP to start of integer callee save spill area 2.
1505 movePastCSLoadStoreOps(MBB, MBBI, ARM::VLDRD, 0, 3, STI);
1506 emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getDPRCalleeSavedAreaSize());
1508 // Move SP to start of integer callee save spill area 1.
1509 movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, ARM::t2LDRi12, 2, STI);
1510 emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea2Size());
1512 // Move SP to SP upon entry to the function.
1513 movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, ARM::t2LDRi12, 1, STI);
1514 emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea1Size());
1518 emitSPUpdate(isARM, MBB, MBBI, dl, TII, VARegSaveSize);
1521 #include "ARMGenRegisterInfo.inc"