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/ErrorHandling.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include "llvm/Target/TargetFrameInfo.h"
35 #include "llvm/Target/TargetMachine.h"
36 #include "llvm/Target/TargetOptions.h"
37 #include "llvm/ADT/BitVector.h"
38 #include "llvm/ADT/SmallVector.h"
41 unsigned ARMBaseRegisterInfo::getRegisterNumbering(unsigned RegEnum,
49 llvm_unreachable("Unknown ARM register!");
50 case R0: case D0: case Q0: return 0;
51 case R1: case D1: case Q1: return 1;
52 case R2: case D2: case Q2: return 2;
53 case R3: case D3: case Q3: return 3;
54 case R4: case D4: case Q4: return 4;
55 case R5: case D5: case Q5: return 5;
56 case R6: case D6: case Q6: return 6;
57 case R7: case D7: case Q7: return 7;
58 case R8: case D8: case Q8: return 8;
59 case R9: case D9: case Q9: return 9;
60 case R10: case D10: case Q10: return 10;
61 case R11: case D11: case Q11: return 11;
62 case R12: case D12: case Q12: return 12;
63 case SP: case D13: case Q13: return 13;
64 case LR: case D14: case Q14: return 14;
65 case PC: case D15: case Q15: return 15;
84 case S0: case S1: case S2: case S3:
85 case S4: case S5: case S6: case S7:
86 case S8: case S9: case S10: case S11:
87 case S12: case S13: case S14: case S15:
88 case S16: case S17: case S18: case S19:
89 case S20: case S21: case S22: case S23:
90 case S24: case S25: case S26: case S27:
91 case S28: case S29: case S30: case S31: {
95 default: return 0; // Avoid compile time warning.
133 ARMBaseRegisterInfo::ARMBaseRegisterInfo(const ARMBaseInstrInfo &tii,
134 const ARMSubtarget &sti)
135 : ARMGenRegisterInfo(ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP),
137 FramePtr((STI.isTargetDarwin() || STI.isThumb()) ? ARM::R7 : ARM::R11) {
141 ARMBaseRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
142 static const unsigned CalleeSavedRegs[] = {
143 ARM::LR, ARM::R11, ARM::R10, ARM::R9, ARM::R8,
144 ARM::R7, ARM::R6, ARM::R5, ARM::R4,
146 ARM::D15, ARM::D14, ARM::D13, ARM::D12,
147 ARM::D11, ARM::D10, ARM::D9, ARM::D8,
151 static const unsigned DarwinCalleeSavedRegs[] = {
152 // Darwin ABI deviates from ARM standard ABI. R9 is not a callee-saved
154 ARM::LR, ARM::R7, ARM::R6, ARM::R5, ARM::R4,
155 ARM::R11, ARM::R10, ARM::R8,
157 ARM::D15, ARM::D14, ARM::D13, ARM::D12,
158 ARM::D11, ARM::D10, ARM::D9, ARM::D8,
161 return STI.isTargetDarwin() ? DarwinCalleeSavedRegs : CalleeSavedRegs;
164 const TargetRegisterClass* const *
165 ARMBaseRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
166 static const TargetRegisterClass * const CalleeSavedRegClasses[] = {
167 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
168 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
169 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
171 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
172 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
176 static const TargetRegisterClass * const ThumbCalleeSavedRegClasses[] = {
177 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
178 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::tGPRRegClass,
179 &ARM::tGPRRegClass,&ARM::tGPRRegClass,&ARM::tGPRRegClass,
181 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
182 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
186 static const TargetRegisterClass * const DarwinCalleeSavedRegClasses[] = {
187 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
188 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
189 &ARM::GPRRegClass, &ARM::GPRRegClass,
191 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
192 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
196 static const TargetRegisterClass * const DarwinThumbCalleeSavedRegClasses[] ={
197 &ARM::GPRRegClass, &ARM::tGPRRegClass, &ARM::tGPRRegClass,
198 &ARM::tGPRRegClass, &ARM::tGPRRegClass, &ARM::GPRRegClass,
199 &ARM::GPRRegClass, &ARM::GPRRegClass,
201 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
202 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
206 if (STI.isThumb1Only()) {
207 return STI.isTargetDarwin()
208 ? DarwinThumbCalleeSavedRegClasses : ThumbCalleeSavedRegClasses;
210 return STI.isTargetDarwin()
211 ? DarwinCalleeSavedRegClasses : CalleeSavedRegClasses;
214 BitVector ARMBaseRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
215 // FIXME: avoid re-calculating this everytime.
216 BitVector Reserved(getNumRegs());
217 Reserved.set(ARM::SP);
218 Reserved.set(ARM::PC);
219 if (STI.isTargetDarwin() || hasFP(MF))
220 Reserved.set(FramePtr);
221 // Some targets reserve R9.
222 if (STI.isR9Reserved())
223 Reserved.set(ARM::R9);
228 ARMBaseRegisterInfo::isReservedReg(const MachineFunction &MF, unsigned Reg) const {
236 if (FramePtr == Reg && (STI.isTargetDarwin() || hasFP(MF)))
240 return STI.isR9Reserved();
246 const TargetRegisterClass *ARMBaseRegisterInfo::getPointerRegClass() const {
247 return &ARM::GPRRegClass;
250 /// getAllocationOrder - Returns the register allocation order for a specified
251 /// register class in the form of a pair of TargetRegisterClass iterators.
252 std::pair<TargetRegisterClass::iterator,TargetRegisterClass::iterator>
253 ARMBaseRegisterInfo::getAllocationOrder(const TargetRegisterClass *RC,
254 unsigned HintType, unsigned HintReg,
255 const MachineFunction &MF) const {
256 // Alternative register allocation orders when favoring even / odd registers
257 // of register pairs.
259 // No FP, R9 is available.
260 static const unsigned GPREven1[] = {
261 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8, ARM::R10,
262 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7,
265 static const unsigned GPROdd1[] = {
266 ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R9, ARM::R11,
267 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6,
271 // FP is R7, R9 is available.
272 static const unsigned GPREven2[] = {
273 ARM::R0, ARM::R2, ARM::R4, ARM::R8, ARM::R10,
274 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6,
277 static const unsigned GPROdd2[] = {
278 ARM::R1, ARM::R3, ARM::R5, ARM::R9, ARM::R11,
279 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6,
283 // FP is R11, R9 is available.
284 static const unsigned GPREven3[] = {
285 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8,
286 ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7,
289 static const unsigned GPROdd3[] = {
290 ARM::R1, ARM::R3, ARM::R5, ARM::R6, ARM::R9,
291 ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R7,
295 // No FP, R9 is not available.
296 static const unsigned GPREven4[] = {
297 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R10,
298 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8,
301 static const unsigned GPROdd4[] = {
302 ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R11,
303 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8,
307 // FP is R7, R9 is not available.
308 static const unsigned GPREven5[] = {
309 ARM::R0, ARM::R2, ARM::R4, ARM::R10,
310 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6, ARM::R8,
313 static const unsigned GPROdd5[] = {
314 ARM::R1, ARM::R3, ARM::R5, ARM::R11,
315 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8,
319 // FP is R11, R9 is not available.
320 static const unsigned GPREven6[] = {
321 ARM::R0, ARM::R2, ARM::R4, ARM::R6,
322 ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8
324 static const unsigned GPROdd6[] = {
325 ARM::R1, ARM::R3, ARM::R5, ARM::R7,
326 ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8
330 if (HintType == ARMRI::RegPairEven) {
331 if (isPhysicalRegister(HintReg) && getRegisterPairEven(HintReg, MF) == 0)
332 // It's no longer possible to fulfill this hint. Return the default
334 return std::make_pair(RC->allocation_order_begin(MF),
335 RC->allocation_order_end(MF));
337 if (!STI.isTargetDarwin() && !hasFP(MF)) {
338 if (!STI.isR9Reserved())
339 return std::make_pair(GPREven1,
340 GPREven1 + (sizeof(GPREven1)/sizeof(unsigned)));
342 return std::make_pair(GPREven4,
343 GPREven4 + (sizeof(GPREven4)/sizeof(unsigned)));
344 } else if (FramePtr == ARM::R7) {
345 if (!STI.isR9Reserved())
346 return std::make_pair(GPREven2,
347 GPREven2 + (sizeof(GPREven2)/sizeof(unsigned)));
349 return std::make_pair(GPREven5,
350 GPREven5 + (sizeof(GPREven5)/sizeof(unsigned)));
351 } else { // FramePtr == ARM::R11
352 if (!STI.isR9Reserved())
353 return std::make_pair(GPREven3,
354 GPREven3 + (sizeof(GPREven3)/sizeof(unsigned)));
356 return std::make_pair(GPREven6,
357 GPREven6 + (sizeof(GPREven6)/sizeof(unsigned)));
359 } else if (HintType == ARMRI::RegPairOdd) {
360 if (isPhysicalRegister(HintReg) && getRegisterPairOdd(HintReg, MF) == 0)
361 // It's no longer possible to fulfill this hint. Return the default
363 return std::make_pair(RC->allocation_order_begin(MF),
364 RC->allocation_order_end(MF));
366 if (!STI.isTargetDarwin() && !hasFP(MF)) {
367 if (!STI.isR9Reserved())
368 return std::make_pair(GPROdd1,
369 GPROdd1 + (sizeof(GPROdd1)/sizeof(unsigned)));
371 return std::make_pair(GPROdd4,
372 GPROdd4 + (sizeof(GPROdd4)/sizeof(unsigned)));
373 } else if (FramePtr == ARM::R7) {
374 if (!STI.isR9Reserved())
375 return std::make_pair(GPROdd2,
376 GPROdd2 + (sizeof(GPROdd2)/sizeof(unsigned)));
378 return std::make_pair(GPROdd5,
379 GPROdd5 + (sizeof(GPROdd5)/sizeof(unsigned)));
380 } else { // FramePtr == ARM::R11
381 if (!STI.isR9Reserved())
382 return std::make_pair(GPROdd3,
383 GPROdd3 + (sizeof(GPROdd3)/sizeof(unsigned)));
385 return std::make_pair(GPROdd6,
386 GPROdd6 + (sizeof(GPROdd6)/sizeof(unsigned)));
389 return std::make_pair(RC->allocation_order_begin(MF),
390 RC->allocation_order_end(MF));
393 /// ResolveRegAllocHint - Resolves the specified register allocation hint
394 /// to a physical register. Returns the physical register if it is successful.
396 ARMBaseRegisterInfo::ResolveRegAllocHint(unsigned Type, unsigned Reg,
397 const MachineFunction &MF) const {
398 if (Reg == 0 || !isPhysicalRegister(Reg))
402 else if (Type == (unsigned)ARMRI::RegPairOdd)
404 return getRegisterPairOdd(Reg, MF);
405 else if (Type == (unsigned)ARMRI::RegPairEven)
407 return getRegisterPairEven(Reg, MF);
412 ARMBaseRegisterInfo::UpdateRegAllocHint(unsigned Reg, unsigned NewReg,
413 MachineFunction &MF) const {
414 MachineRegisterInfo *MRI = &MF.getRegInfo();
415 std::pair<unsigned, unsigned> Hint = MRI->getRegAllocationHint(Reg);
416 if ((Hint.first == (unsigned)ARMRI::RegPairOdd ||
417 Hint.first == (unsigned)ARMRI::RegPairEven) &&
418 Hint.second && TargetRegisterInfo::isVirtualRegister(Hint.second)) {
419 // If 'Reg' is one of the even / odd register pair and it's now changed
420 // (e.g. coalesced) into a different register. The other register of the
421 // pair allocation hint must be updated to reflect the relationship
423 unsigned OtherReg = Hint.second;
424 Hint = MRI->getRegAllocationHint(OtherReg);
425 if (Hint.second == Reg)
426 // Make sure the pair has not already divorced.
427 MRI->setRegAllocationHint(OtherReg, Hint.first, NewReg);
431 /// hasFP - Return true if the specified function should have a dedicated frame
432 /// pointer register. This is true if the function has variable sized allocas
433 /// or if frame pointer elimination is disabled.
435 bool ARMBaseRegisterInfo::hasFP(const MachineFunction &MF) const {
436 const MachineFrameInfo *MFI = MF.getFrameInfo();
437 return (NoFramePointerElim ||
438 MFI->hasVarSizedObjects() ||
439 MFI->isFrameAddressTaken());
442 static unsigned estimateStackSize(MachineFunction &MF, MachineFrameInfo *MFI) {
443 const MachineFrameInfo *FFI = MF.getFrameInfo();
445 for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) {
446 int FixedOff = -FFI->getObjectOffset(i);
447 if (FixedOff > Offset) Offset = FixedOff;
449 for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
450 if (FFI->isDeadObjectIndex(i))
452 Offset += FFI->getObjectSize(i);
453 unsigned Align = FFI->getObjectAlignment(i);
454 // Adjust to alignment boundary
455 Offset = (Offset+Align-1)/Align*Align;
457 return (unsigned)Offset;
461 ARMBaseRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
462 RegScavenger *RS) const {
463 // This tells PEI to spill the FP as if it is any other callee-save register
464 // to take advantage the eliminateFrameIndex machinery. This also ensures it
465 // is spilled in the order specified by getCalleeSavedRegs() to make it easier
466 // to combine multiple loads / stores.
467 bool CanEliminateFrame = true;
468 bool CS1Spilled = false;
469 bool LRSpilled = false;
470 unsigned NumGPRSpills = 0;
471 SmallVector<unsigned, 4> UnspilledCS1GPRs;
472 SmallVector<unsigned, 4> UnspilledCS2GPRs;
473 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
475 // Don't spill FP if the frame can be eliminated. This is determined
476 // by scanning the callee-save registers to see if any is used.
477 const unsigned *CSRegs = getCalleeSavedRegs();
478 const TargetRegisterClass* const *CSRegClasses = getCalleeSavedRegClasses();
479 for (unsigned i = 0; CSRegs[i]; ++i) {
480 unsigned Reg = CSRegs[i];
481 bool Spilled = false;
482 if (MF.getRegInfo().isPhysRegUsed(Reg)) {
483 AFI->setCSRegisterIsSpilled(Reg);
485 CanEliminateFrame = false;
487 // Check alias registers too.
488 for (const unsigned *Aliases = getAliasSet(Reg); *Aliases; ++Aliases) {
489 if (MF.getRegInfo().isPhysRegUsed(*Aliases)) {
491 CanEliminateFrame = false;
496 if (CSRegClasses[i] == &ARM::GPRRegClass) {
500 if (!STI.isTargetDarwin()) {
507 // Keep track if LR and any of R4, R5, R6, and R7 is spilled.
522 if (!STI.isTargetDarwin()) {
523 UnspilledCS1GPRs.push_back(Reg);
533 UnspilledCS1GPRs.push_back(Reg);
536 UnspilledCS2GPRs.push_back(Reg);
543 bool ForceLRSpill = false;
544 if (!LRSpilled && AFI->isThumb1OnlyFunction()) {
545 unsigned FnSize = TII.GetFunctionSizeInBytes(MF);
546 // Force LR to be spilled if the Thumb function size is > 2048. This enables
547 // use of BL to implement far jump. If it turns out that it's not needed
548 // then the branch fix up path will undo it.
549 if (FnSize >= (1 << 11)) {
550 CanEliminateFrame = false;
555 bool ExtraCSSpill = false;
556 if (!CanEliminateFrame || hasFP(MF)) {
557 AFI->setHasStackFrame(true);
559 // If LR is not spilled, but at least one of R4, R5, R6, and R7 is spilled.
560 // Spill LR as well so we can fold BX_RET to the registers restore (LDM).
561 if (!LRSpilled && CS1Spilled) {
562 MF.getRegInfo().setPhysRegUsed(ARM::LR);
563 AFI->setCSRegisterIsSpilled(ARM::LR);
565 UnspilledCS1GPRs.erase(std::find(UnspilledCS1GPRs.begin(),
566 UnspilledCS1GPRs.end(), (unsigned)ARM::LR));
567 ForceLRSpill = false;
571 // Darwin ABI requires FP to point to the stack slot that contains the
573 if (STI.isTargetDarwin() || hasFP(MF)) {
574 MF.getRegInfo().setPhysRegUsed(FramePtr);
578 // If stack and double are 8-byte aligned and we are spilling an odd number
579 // of GPRs. Spill one extra callee save GPR so we won't have to pad between
580 // the integer and double callee save areas.
581 unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
582 if (TargetAlign == 8 && (NumGPRSpills & 1)) {
583 if (CS1Spilled && !UnspilledCS1GPRs.empty()) {
584 for (unsigned i = 0, e = UnspilledCS1GPRs.size(); i != e; ++i) {
585 unsigned Reg = UnspilledCS1GPRs[i];
586 // Don't spill high register if the function is thumb1
587 if (!AFI->isThumb1OnlyFunction() ||
588 isARMLowRegister(Reg) || Reg == ARM::LR) {
589 MF.getRegInfo().setPhysRegUsed(Reg);
590 AFI->setCSRegisterIsSpilled(Reg);
591 if (!isReservedReg(MF, Reg))
596 } else if (!UnspilledCS2GPRs.empty() &&
597 !AFI->isThumb1OnlyFunction()) {
598 unsigned Reg = UnspilledCS2GPRs.front();
599 MF.getRegInfo().setPhysRegUsed(Reg);
600 AFI->setCSRegisterIsSpilled(Reg);
601 if (!isReservedReg(MF, Reg))
606 // Estimate if we might need to scavenge a register at some point in order
607 // to materialize a stack offset. If so, either spill one additional
608 // callee-saved register or reserve a special spill slot to facilitate
609 // register scavenging.
610 if (RS && !ExtraCSSpill && !AFI->isThumb1OnlyFunction()) {
611 MachineFrameInfo *MFI = MF.getFrameInfo();
612 unsigned Size = estimateStackSize(MF, MFI);
613 unsigned Limit = (1 << 12) - 1;
614 for (MachineFunction::iterator BB = MF.begin(),E = MF.end();BB != E; ++BB)
615 for (MachineBasicBlock::iterator I= BB->begin(); I != BB->end(); ++I) {
616 for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
617 if (I->getOperand(i).isFI()) {
618 unsigned Opcode = I->getOpcode();
619 const TargetInstrDesc &Desc = TII.get(Opcode);
620 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
621 if (AddrMode == ARMII::AddrMode3) {
622 Limit = (1 << 8) - 1;
624 } else if (AddrMode == ARMII::AddrMode5) {
625 unsigned ThisLimit = ((1 << 8) - 1) * 4;
626 if (ThisLimit < Limit)
633 // If any non-reserved CS register isn't spilled, just spill one or two
634 // extra. That should take care of it!
635 unsigned NumExtras = TargetAlign / 4;
636 SmallVector<unsigned, 2> Extras;
637 while (NumExtras && !UnspilledCS1GPRs.empty()) {
638 unsigned Reg = UnspilledCS1GPRs.back();
639 UnspilledCS1GPRs.pop_back();
640 if (!isReservedReg(MF, Reg)) {
641 Extras.push_back(Reg);
645 while (NumExtras && !UnspilledCS2GPRs.empty()) {
646 unsigned Reg = UnspilledCS2GPRs.back();
647 UnspilledCS2GPRs.pop_back();
648 if (!isReservedReg(MF, Reg)) {
649 Extras.push_back(Reg);
653 if (Extras.size() && NumExtras == 0) {
654 for (unsigned i = 0, e = Extras.size(); i != e; ++i) {
655 MF.getRegInfo().setPhysRegUsed(Extras[i]);
656 AFI->setCSRegisterIsSpilled(Extras[i]);
659 // Reserve a slot closest to SP or frame pointer.
660 const TargetRegisterClass *RC = &ARM::GPRRegClass;
661 RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
662 RC->getAlignment()));
669 MF.getRegInfo().setPhysRegUsed(ARM::LR);
670 AFI->setCSRegisterIsSpilled(ARM::LR);
671 AFI->setLRIsSpilledForFarJump(true);
675 unsigned ARMBaseRegisterInfo::getRARegister() const {
679 unsigned ARMBaseRegisterInfo::getFrameRegister(MachineFunction &MF) const {
680 if (STI.isTargetDarwin() || hasFP(MF))
685 unsigned ARMBaseRegisterInfo::getEHExceptionRegister() const {
686 llvm_unreachable("What is the exception register");
690 unsigned ARMBaseRegisterInfo::getEHHandlerRegister() const {
691 llvm_unreachable("What is the exception handler register");
695 int ARMBaseRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
696 return ARMGenRegisterInfo::getDwarfRegNumFull(RegNum, 0);
699 unsigned ARMBaseRegisterInfo::getRegisterPairEven(unsigned Reg,
700 const MachineFunction &MF) const {
703 // Return 0 if either register of the pair is a special register.
709 return STI.isThumb1Only() ? 0 : ARM::R2;
713 return isReservedReg(MF, ARM::R7) ? 0 : ARM::R6;
715 return isReservedReg(MF, ARM::R9) ? 0 :ARM::R8;
717 return isReservedReg(MF, ARM::R11) ? 0 : ARM::R10;
789 unsigned ARMBaseRegisterInfo::getRegisterPairOdd(unsigned Reg,
790 const MachineFunction &MF) const {
793 // Return 0 if either register of the pair is a special register.
799 return STI.isThumb1Only() ? 0 : ARM::R3;
803 return isReservedReg(MF, ARM::R7) ? 0 : ARM::R7;
805 return isReservedReg(MF, ARM::R9) ? 0 :ARM::R9;
807 return isReservedReg(MF, ARM::R11) ? 0 : ARM::R11;
879 /// emitLoadConstPool - Emits a load from constpool to materialize the
880 /// specified immediate.
881 void ARMBaseRegisterInfo::
882 emitLoadConstPool(MachineBasicBlock &MBB,
883 MachineBasicBlock::iterator &MBBI,
885 unsigned DestReg, unsigned SubIdx, int Val,
886 ARMCC::CondCodes Pred,
887 unsigned PredReg) const {
888 MachineFunction &MF = *MBB.getParent();
889 MachineConstantPool *ConstantPool = MF.getConstantPool();
890 Constant *C = ConstantInt::get(Type::Int32Ty, Val);
891 unsigned Idx = ConstantPool->getConstantPoolIndex(C, 4);
893 BuildMI(MBB, MBBI, dl, TII.get(ARM::LDRcp))
894 .addReg(DestReg, getDefRegState(true), SubIdx)
895 .addConstantPoolIndex(Idx)
896 .addReg(0).addImm(0).addImm(Pred).addReg(PredReg);
899 bool ARMBaseRegisterInfo::
900 requiresRegisterScavenging(const MachineFunction &MF) const {
904 // hasReservedCallFrame - Under normal circumstances, when a frame pointer is
905 // not required, we reserve argument space for call sites in the function
906 // immediately on entry to the current function. This eliminates the need for
907 // add/sub sp brackets around call sites. Returns true if the call frame is
908 // included as part of the stack frame.
909 bool ARMBaseRegisterInfo::
910 hasReservedCallFrame(MachineFunction &MF) const {
911 const MachineFrameInfo *FFI = MF.getFrameInfo();
912 unsigned CFSize = FFI->getMaxCallFrameSize();
913 // It's not always a good idea to include the call frame as part of the
914 // stack frame. ARM (especially Thumb) has small immediate offset to
915 // address the stack frame. So a large call frame can cause poor codegen
916 // and may even makes it impossible to scavenge a register.
917 if (CFSize >= ((1 << 12) - 1) / 2) // Half of imm12
920 return !MF.getFrameInfo()->hasVarSizedObjects();
924 emitSPUpdate(bool isARM,
925 MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
926 DebugLoc dl, const ARMBaseInstrInfo &TII,
928 ARMCC::CondCodes Pred = ARMCC::AL, unsigned PredReg = 0) {
930 emitARMRegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
933 emitT2RegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
938 void ARMBaseRegisterInfo::
939 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
940 MachineBasicBlock::iterator I) const {
941 if (!hasReservedCallFrame(MF)) {
942 // If we have alloca, convert as follows:
943 // ADJCALLSTACKDOWN -> sub, sp, sp, amount
944 // ADJCALLSTACKUP -> add, sp, sp, amount
945 MachineInstr *Old = I;
946 DebugLoc dl = Old->getDebugLoc();
947 unsigned Amount = Old->getOperand(0).getImm();
949 // We need to keep the stack aligned properly. To do this, we round the
950 // amount of space needed for the outgoing arguments up to the next
951 // alignment boundary.
952 unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
953 Amount = (Amount+Align-1)/Align*Align;
955 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
956 assert(!AFI->isThumb1OnlyFunction() &&
957 "This eliminateCallFramePseudoInstr does not suppor Thumb1!");
958 bool isARM = !AFI->isThumbFunction();
960 // Replace the pseudo instruction with a new instruction...
961 unsigned Opc = Old->getOpcode();
962 ARMCC::CondCodes Pred = (ARMCC::CondCodes)Old->getOperand(1).getImm();
963 // FIXME: Thumb2 version of ADJCALLSTACKUP and ADJCALLSTACKDOWN?
964 if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) {
965 // Note: PredReg is operand 2 for ADJCALLSTACKDOWN.
966 unsigned PredReg = Old->getOperand(2).getReg();
967 emitSPUpdate(isARM, MBB, I, dl, TII, -Amount, Pred, PredReg);
969 // Note: PredReg is operand 3 for ADJCALLSTACKUP.
970 unsigned PredReg = Old->getOperand(3).getReg();
971 assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP);
972 emitSPUpdate(isARM, MBB, I, dl, TII, Amount, Pred, PredReg);
979 /// findScratchRegister - Find a 'free' ARM register. If register scavenger
980 /// is not being used, R12 is available. Otherwise, try for a call-clobbered
981 /// register first and then a spilled callee-saved register if that fails.
983 unsigned findScratchRegister(RegScavenger *RS, const TargetRegisterClass *RC,
984 ARMFunctionInfo *AFI) {
985 unsigned Reg = RS ? RS->FindUnusedReg(RC, true) : (unsigned) ARM::R12;
986 assert(!AFI->isThumb1OnlyFunction());
988 // Try a already spilled CS register.
989 Reg = RS->FindUnusedReg(RC, AFI->getSpilledCSRegisters());
995 ARMBaseRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
996 int SPAdj, RegScavenger *RS) const {
998 MachineInstr &MI = *II;
999 MachineBasicBlock &MBB = *MI.getParent();
1000 MachineFunction &MF = *MBB.getParent();
1001 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1002 assert(!AFI->isThumb1OnlyFunction() &&
1003 "This eliminateFrameIndex does not suppor Thumb1!");
1005 while (!MI.getOperand(i).isFI()) {
1007 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
1010 unsigned FrameReg = ARM::SP;
1011 int FrameIndex = MI.getOperand(i).getIndex();
1012 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
1013 MF.getFrameInfo()->getStackSize() + SPAdj;
1015 if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
1016 Offset -= AFI->getGPRCalleeSavedArea1Offset();
1017 else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
1018 Offset -= AFI->getGPRCalleeSavedArea2Offset();
1019 else if (AFI->isDPRCalleeSavedAreaFrame(FrameIndex))
1020 Offset -= AFI->getDPRCalleeSavedAreaOffset();
1021 else if (hasFP(MF)) {
1022 assert(SPAdj == 0 && "Unexpected");
1023 // There is alloca()'s in this function, must reference off the frame
1025 FrameReg = getFrameRegister(MF);
1026 Offset -= AFI->getFramePtrSpillOffset();
1029 // modify MI as necessary to handle as much of 'Offset' as possible
1030 if (!AFI->isThumbFunction())
1031 Offset = rewriteARMFrameIndex(MI, i, FrameReg, Offset, TII);
1033 assert(AFI->isThumb2Function());
1034 Offset = rewriteT2FrameIndex(MI, i, FrameReg, Offset, TII);
1039 // If we get here, the immediate doesn't fit into the instruction. We folded
1040 // as much as possible above, handle the rest, providing a register that is
1042 assert(Offset && "This code isn't needed if offset already handled!");
1044 // Insert a set of r12 with the full address: r12 = sp + offset
1045 // If the offset we have is too large to fit into the instruction, we need
1046 // to form it with a series of ADDri's. Do this by taking 8-bit chunks
1048 unsigned ScratchReg = findScratchRegister(RS, &ARM::GPRRegClass, AFI);
1049 if (ScratchReg == 0)
1050 // No register is "free". Scavenge a register.
1051 ScratchReg = RS->scavengeRegister(&ARM::GPRRegClass, II, SPAdj);
1052 int PIdx = MI.findFirstPredOperandIdx();
1053 ARMCC::CondCodes Pred = (PIdx == -1)
1054 ? ARMCC::AL : (ARMCC::CondCodes)MI.getOperand(PIdx).getImm();
1055 unsigned PredReg = (PIdx == -1) ? 0 : MI.getOperand(PIdx+1).getReg();
1056 if (!AFI->isThumbFunction())
1057 emitARMRegPlusImmediate(MBB, II, MI.getDebugLoc(), ScratchReg, FrameReg,
1058 Offset, Pred, PredReg, TII);
1060 assert(AFI->isThumb2Function());
1061 emitT2RegPlusImmediate(MBB, II, MI.getDebugLoc(), ScratchReg, FrameReg,
1062 Offset, Pred, PredReg, TII);
1064 MI.getOperand(i).ChangeToRegister(ScratchReg, false, false, true);
1067 /// Move iterator pass the next bunch of callee save load / store ops for
1068 /// the particular spill area (1: integer area 1, 2: integer area 2,
1069 /// 3: fp area, 0: don't care).
1070 static void movePastCSLoadStoreOps(MachineBasicBlock &MBB,
1071 MachineBasicBlock::iterator &MBBI,
1072 int Opc1, int Opc2, unsigned Area,
1073 const ARMSubtarget &STI) {
1074 while (MBBI != MBB.end() &&
1075 ((MBBI->getOpcode() == Opc1) || (MBBI->getOpcode() == Opc2)) &&
1076 MBBI->getOperand(1).isFI()) {
1079 unsigned Category = 0;
1080 switch (MBBI->getOperand(0).getReg()) {
1081 case ARM::R4: case ARM::R5: case ARM::R6: case ARM::R7:
1085 case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11:
1086 Category = STI.isTargetDarwin() ? 2 : 1;
1088 case ARM::D8: case ARM::D9: case ARM::D10: case ARM::D11:
1089 case ARM::D12: case ARM::D13: case ARM::D14: case ARM::D15:
1096 if (Done || Category != Area)
1104 void ARMBaseRegisterInfo::
1105 emitPrologue(MachineFunction &MF) const {
1106 MachineBasicBlock &MBB = MF.front();
1107 MachineBasicBlock::iterator MBBI = MBB.begin();
1108 MachineFrameInfo *MFI = MF.getFrameInfo();
1109 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1110 assert(!AFI->isThumb1OnlyFunction() &&
1111 "This emitPrologue does not suppor Thumb1!");
1112 bool isARM = !AFI->isThumbFunction();
1113 unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
1114 unsigned NumBytes = MFI->getStackSize();
1115 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
1116 DebugLoc dl = (MBBI != MBB.end() ?
1117 MBBI->getDebugLoc() : DebugLoc::getUnknownLoc());
1119 // Determine the sizes of each callee-save spill areas and record which frame
1120 // belongs to which callee-save spill areas.
1121 unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
1122 int FramePtrSpillFI = 0;
1125 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -VARegSaveSize);
1127 if (!AFI->hasStackFrame()) {
1129 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes);
1133 for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
1134 unsigned Reg = CSI[i].getReg();
1135 int FI = CSI[i].getFrameIdx();
1142 if (Reg == FramePtr)
1143 FramePtrSpillFI = FI;
1144 AFI->addGPRCalleeSavedArea1Frame(FI);
1151 if (Reg == FramePtr)
1152 FramePtrSpillFI = FI;
1153 if (STI.isTargetDarwin()) {
1154 AFI->addGPRCalleeSavedArea2Frame(FI);
1157 AFI->addGPRCalleeSavedArea1Frame(FI);
1162 AFI->addDPRCalleeSavedAreaFrame(FI);
1167 // Build the new SUBri to adjust SP for integer callee-save spill area 1.
1168 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS1Size);
1169 movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, ARM::t2STRi12, 1, STI);
1171 // Darwin ABI requires FP to point to the stack slot that contains the
1173 if (STI.isTargetDarwin() || hasFP(MF)) {
1174 unsigned ADDriOpc = !AFI->isThumbFunction() ? ARM::ADDri : ARM::t2ADDri;
1175 MachineInstrBuilder MIB =
1176 BuildMI(MBB, MBBI, dl, TII.get(ADDriOpc), FramePtr)
1177 .addFrameIndex(FramePtrSpillFI).addImm(0);
1178 AddDefaultCC(AddDefaultPred(MIB));
1181 // Build the new SUBri to adjust SP for integer callee-save spill area 2.
1182 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS2Size);
1184 // Build the new SUBri to adjust SP for FP callee-save spill area.
1185 movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, ARM::t2STRi12, 2, STI);
1186 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -DPRCSSize);
1188 // Determine starting offsets of spill areas.
1189 unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
1190 unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
1191 unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
1192 AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) + NumBytes);
1193 AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
1194 AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
1195 AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
1197 NumBytes = DPRCSOffset;
1199 // Insert it after all the callee-save spills.
1200 movePastCSLoadStoreOps(MBB, MBBI, ARM::FSTD, 0, 3, STI);
1201 emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes);
1204 if (STI.isTargetELF() && hasFP(MF)) {
1205 MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
1206 AFI->getFramePtrSpillOffset());
1209 AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
1210 AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
1211 AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
1214 static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
1215 for (unsigned i = 0; CSRegs[i]; ++i)
1216 if (Reg == CSRegs[i])
1221 static bool isCSRestore(MachineInstr *MI,
1222 const ARMBaseInstrInfo &TII,
1223 const unsigned *CSRegs) {
1224 return ((MI->getOpcode() == (int)ARM::FLDD ||
1225 MI->getOpcode() == (int)ARM::LDR ||
1226 MI->getOpcode() == (int)ARM::t2LDRi12) &&
1227 MI->getOperand(1).isFI() &&
1228 isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs));
1231 void ARMBaseRegisterInfo::
1232 emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const {
1233 MachineBasicBlock::iterator MBBI = prior(MBB.end());
1234 assert(MBBI->getDesc().isReturn() &&
1235 "Can only insert epilog into returning blocks");
1236 DebugLoc dl = MBBI->getDebugLoc();
1237 MachineFrameInfo *MFI = MF.getFrameInfo();
1238 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1239 assert(!AFI->isThumb1OnlyFunction() &&
1240 "This emitEpilogue does not suppor Thumb1!");
1241 bool isARM = !AFI->isThumbFunction();
1243 unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
1244 int NumBytes = (int)MFI->getStackSize();
1246 if (!AFI->hasStackFrame()) {
1248 emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
1250 // Unwind MBBI to point to first LDR / FLDD.
1251 const unsigned *CSRegs = getCalleeSavedRegs();
1252 if (MBBI != MBB.begin()) {
1255 while (MBBI != MBB.begin() && isCSRestore(MBBI, TII, CSRegs));
1256 if (!isCSRestore(MBBI, TII, CSRegs))
1260 // Move SP to start of FP callee save spill area.
1261 NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
1262 AFI->getGPRCalleeSavedArea2Size() +
1263 AFI->getDPRCalleeSavedAreaSize());
1265 // Darwin ABI requires FP to point to the stack slot that contains the
1267 if ((STI.isTargetDarwin() && NumBytes) || hasFP(MF)) {
1268 NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
1269 // Reset SP based on frame pointer only if the stack frame extends beyond
1270 // frame pointer stack slot or target is ELF and the function has FP.
1271 if (AFI->getGPRCalleeSavedArea2Size() ||
1272 AFI->getDPRCalleeSavedAreaSize() ||
1273 AFI->getDPRCalleeSavedAreaOffset()||
1276 unsigned SUBriOpc = isARM ? ARM::SUBri : ARM::t2SUBri;
1277 BuildMI(MBB, MBBI, dl, TII.get(SUBriOpc), ARM::SP)
1280 .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
1283 unsigned MOVrOpc = isARM ? ARM::MOVr : ARM::t2MOVr;
1284 BuildMI(MBB, MBBI, dl, TII.get(MOVrOpc), ARM::SP)
1286 .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
1289 } else if (NumBytes)
1290 emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
1292 // Move SP to start of integer callee save spill area 2.
1293 movePastCSLoadStoreOps(MBB, MBBI, ARM::FLDD, 0, 3, STI);
1294 emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getDPRCalleeSavedAreaSize());
1296 // Move SP to start of integer callee save spill area 1.
1297 movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, ARM::t2LDRi12, 2, STI);
1298 emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea2Size());
1300 // Move SP to SP upon entry to the function.
1301 movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, ARM::t2LDRi12, 1, STI);
1302 emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea1Size());
1306 emitSPUpdate(isARM, MBB, MBBI, dl, TII, VARegSaveSize);
1309 #include "ARMGenRegisterInfo.inc"