1 //===- ARMRegisterInfo.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 ARM implementation of the TargetRegisterInfo class.
12 //===----------------------------------------------------------------------===//
15 #include "ARMAddressingModes.h"
16 #include "ARMInstrInfo.h"
17 #include "ARMMachineFunctionInfo.h"
18 #include "ARMRegisterInfo.h"
19 #include "ARMSubtarget.h"
20 #include "llvm/Constants.h"
21 #include "llvm/DerivedTypes.h"
22 #include "llvm/CodeGen/MachineConstantPool.h"
23 #include "llvm/CodeGen/MachineFrameInfo.h"
24 #include "llvm/CodeGen/MachineFunction.h"
25 #include "llvm/CodeGen/MachineInstrBuilder.h"
26 #include "llvm/CodeGen/MachineLocation.h"
27 #include "llvm/CodeGen/MachineRegisterInfo.h"
28 #include "llvm/CodeGen/RegisterScavenging.h"
29 #include "llvm/Target/TargetFrameInfo.h"
30 #include "llvm/Target/TargetMachine.h"
31 #include "llvm/Target/TargetOptions.h"
32 #include "llvm/ADT/BitVector.h"
33 #include "llvm/ADT/SmallVector.h"
34 #include "llvm/ADT/STLExtras.h"
35 #include "llvm/Support/CommandLine.h"
39 static cl::opt<bool> ThumbRegScavenging("enable-thumb-reg-scavenging",
41 cl::desc("Enable register scavenging on Thumb"));
43 unsigned ARMRegisterInfo::getRegisterNumbering(unsigned RegEnum) {
46 case R0: case S0: case D0: return 0;
47 case R1: case S1: case D1: return 1;
48 case R2: case S2: case D2: return 2;
49 case R3: case S3: case D3: return 3;
50 case R4: case S4: case D4: return 4;
51 case R5: case S5: case D5: return 5;
52 case R6: case S6: case D6: return 6;
53 case R7: case S7: case D7: return 7;
54 case R8: case S8: case D8: return 8;
55 case R9: case S9: case D9: return 9;
56 case R10: case S10: case D10: return 10;
57 case R11: case S11: case D11: return 11;
58 case R12: case S12: case D12: return 12;
59 case SP: case S13: case D13: return 13;
60 case LR: case S14: case D14: return 14;
61 case PC: case S15: case D15: return 15;
79 assert(0 && "Unknown ARM register!");
84 unsigned ARMRegisterInfo::getRegisterNumbering(unsigned RegEnum,
91 assert(0 && "Unknown ARM register!");
93 case R0: case D0: return 0;
94 case R1: case D1: return 1;
95 case R2: case D2: return 2;
96 case R3: case D3: return 3;
97 case R4: case D4: return 4;
98 case R5: case D5: return 5;
99 case R6: case D6: return 6;
100 case R7: case D7: return 7;
101 case R8: case D8: return 8;
102 case R9: case D9: return 9;
103 case R10: case D10: return 10;
104 case R11: case D11: return 11;
105 case R12: case D12: return 12;
106 case SP: case D13: return 13;
107 case LR: case D14: return 14;
108 case PC: case D15: return 15;
110 case S0: case S1: case S2: case S3:
111 case S4: case S5: case S6: case S7:
112 case S8: case S9: case S10: case S11:
113 case S12: case S13: case S14: case S15:
114 case S16: case S17: case S18: case S19:
115 case S20: case S21: case S22: case S23:
116 case S24: case S25: case S26: case S27:
117 case S28: case S29: case S30: case S31: {
120 default: return 0; // Avoid compile time warning.
158 ARMRegisterInfo::ARMRegisterInfo(const TargetInstrInfo &tii,
159 const ARMSubtarget &sti)
160 : ARMGenRegisterInfo(ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP),
162 FramePtr((STI.useThumbBacktraces() || STI.isThumb()) ? ARM::R7 : ARM::R11) {
166 const MachineInstrBuilder &AddDefaultPred(const MachineInstrBuilder &MIB) {
167 return MIB.addImm((int64_t)ARMCC::AL).addReg(0);
171 const MachineInstrBuilder &AddDefaultCC(const MachineInstrBuilder &MIB) {
172 return MIB.addReg(0);
175 /// emitLoadConstPool - Emits a load from constpool to materialize the
176 /// specified immediate.
177 void ARMRegisterInfo::emitLoadConstPool(MachineBasicBlock &MBB,
178 MachineBasicBlock::iterator &MBBI,
179 unsigned DestReg, int Val,
180 unsigned Pred, unsigned PredReg,
181 const TargetInstrInfo *TII,
184 MachineFunction &MF = *MBB.getParent();
185 MachineConstantPool *ConstantPool = MF.getConstantPool();
186 Constant *C = ConstantInt::get(Type::Int32Ty, Val);
187 unsigned Idx = ConstantPool->getConstantPoolIndex(C, 4);
189 BuildMI(MBB, MBBI, dl,
190 TII->get(ARM::tLDRcp),DestReg).addConstantPoolIndex(Idx);
192 BuildMI(MBB, MBBI, dl, TII->get(ARM::LDRcp), DestReg)
193 .addConstantPoolIndex(Idx)
194 .addReg(0).addImm(0).addImm(Pred).addReg(PredReg);
197 /// isLowRegister - Returns true if the register is low register r0-r7.
199 bool ARMRegisterInfo::isLowRegister(unsigned Reg) const {
202 case R0: case R1: case R2: case R3:
203 case R4: case R5: case R6: case R7:
210 const TargetRegisterClass*
211 ARMRegisterInfo::getPhysicalRegisterRegClass(unsigned Reg, MVT VT) const {
213 if (isLowRegister(Reg))
214 return ARM::tGPRRegisterClass;
218 case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11:
219 case ARM::R12: case ARM::SP: case ARM::LR: case ARM::PC:
220 return ARM::GPRRegisterClass;
223 return TargetRegisterInfo::getPhysicalRegisterRegClass(Reg, VT);
227 ARMRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
228 static const unsigned CalleeSavedRegs[] = {
229 ARM::LR, ARM::R11, ARM::R10, ARM::R9, ARM::R8,
230 ARM::R7, ARM::R6, ARM::R5, ARM::R4,
232 ARM::D15, ARM::D14, ARM::D13, ARM::D12,
233 ARM::D11, ARM::D10, ARM::D9, ARM::D8,
237 static const unsigned DarwinCalleeSavedRegs[] = {
238 ARM::LR, ARM::R7, ARM::R6, ARM::R5, ARM::R4,
239 ARM::R11, ARM::R10, ARM::R9, ARM::R8,
241 ARM::D15, ARM::D14, ARM::D13, ARM::D12,
242 ARM::D11, ARM::D10, ARM::D9, ARM::D8,
245 return STI.isTargetDarwin() ? DarwinCalleeSavedRegs : CalleeSavedRegs;
248 const TargetRegisterClass* const *
249 ARMRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
250 static const TargetRegisterClass * const CalleeSavedRegClasses[] = {
251 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
252 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
253 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
255 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
256 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
259 static const TargetRegisterClass * const ThumbCalleeSavedRegClasses[] = {
260 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
261 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::tGPRRegClass,
262 &ARM::tGPRRegClass,&ARM::tGPRRegClass,&ARM::tGPRRegClass,
264 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
265 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
268 return STI.isThumb() ? ThumbCalleeSavedRegClasses : CalleeSavedRegClasses;
271 BitVector ARMRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
272 // FIXME: avoid re-calculating this everytime.
273 BitVector Reserved(getNumRegs());
274 Reserved.set(ARM::SP);
275 Reserved.set(ARM::PC);
276 if (STI.isTargetDarwin() || hasFP(MF))
277 Reserved.set(FramePtr);
278 // Some targets reserve R9.
279 if (STI.isR9Reserved())
280 Reserved.set(ARM::R9);
285 ARMRegisterInfo::isReservedReg(const MachineFunction &MF, unsigned Reg) const {
293 if (FramePtr == Reg && (STI.isTargetDarwin() || hasFP(MF)))
297 return STI.isR9Reserved();
303 const TargetRegisterClass *ARMRegisterInfo::getPointerRegClass() const {
304 return &ARM::GPRRegClass;
307 /// getAllocationOrder - Returns the register allocation order for a specified
308 /// register class in the form of a pair of TargetRegisterClass iterators.
309 std::pair<TargetRegisterClass::iterator,TargetRegisterClass::iterator>
310 ARMRegisterInfo::getAllocationOrder(const TargetRegisterClass *RC,
311 std::pair<unsigned, unsigned> Hint,
312 const MachineFunction &MF) const {
313 // Alternative register allocation orders when favoring even / odd registers
314 // of register pairs.
316 // No FP, R9 is available.
317 static const unsigned GPREven1[] = {
318 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8, ARM::R10,
319 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7,
322 static const unsigned GPROdd1[] = {
323 ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R9, ARM::R11,
324 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6,
328 // FP is R7, R9 is available.
329 static const unsigned GPREven2[] = {
330 ARM::R0, ARM::R2, ARM::R4, ARM::R8, ARM::R10,
331 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6,
334 static const unsigned GPROdd2[] = {
335 ARM::R1, ARM::R3, ARM::R5, ARM::R9, ARM::R11,
336 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6,
340 // FP is R11, R9 is available.
341 static const unsigned GPREven3[] = {
342 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R8,
343 ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7,
346 static const unsigned GPROdd3[] = {
347 ARM::R1, ARM::R3, ARM::R5, ARM::R6, ARM::R9,
348 ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R7,
352 // No FP, R9 is not available.
353 static const unsigned GPREven4[] = {
354 ARM::R0, ARM::R2, ARM::R4, ARM::R6, ARM::R10,
355 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8,
358 static const unsigned GPROdd4[] = {
359 ARM::R1, ARM::R3, ARM::R5, ARM::R7, ARM::R11,
360 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8,
364 // FP is R7, R9 is not available.
365 static const unsigned GPREven5[] = {
366 ARM::R0, ARM::R2, ARM::R4, ARM::R10,
367 ARM::R1, ARM::R3, ARM::R12,ARM::LR, ARM::R5, ARM::R6, ARM::R8,
370 static const unsigned GPROdd5[] = {
371 ARM::R1, ARM::R3, ARM::R5, ARM::R11,
372 ARM::R0, ARM::R2, ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8,
376 // FP is R11, R9 is not available.
377 static const unsigned GPREven6[] = {
378 ARM::R0, ARM::R2, ARM::R4, ARM::R6,
379 ARM::R1, ARM::R3, ARM::R10,ARM::R12,ARM::LR, ARM::R5, ARM::R7, ARM::R8
381 static const unsigned GPROdd6[] = {
382 ARM::R1, ARM::R3, ARM::R5, ARM::R7,
383 ARM::R0, ARM::R2, ARM::R10,ARM::R12,ARM::LR, ARM::R4, ARM::R6, ARM::R8
387 if (Hint.first == ARMRI::RegPairEven) {
388 if (!STI.isTargetDarwin() && !hasFP(MF)) {
389 if (!STI.isR9Reserved())
390 return std::make_pair(GPREven1,
391 GPREven1 + (sizeof(GPREven1)/sizeof(unsigned)));
393 return std::make_pair(GPREven4,
394 GPREven4 + (sizeof(GPREven4)/sizeof(unsigned)));
395 } else if (FramePtr == ARM::R7) {
396 if (!STI.isR9Reserved())
397 return std::make_pair(GPREven2,
398 GPREven2 + (sizeof(GPREven2)/sizeof(unsigned)));
400 return std::make_pair(GPREven5,
401 GPREven5 + (sizeof(GPREven5)/sizeof(unsigned)));
402 } else { // FramePtr == ARM::R11
403 if (!STI.isR9Reserved())
404 return std::make_pair(GPREven3,
405 GPREven3 + (sizeof(GPREven3)/sizeof(unsigned)));
407 return std::make_pair(GPREven6,
408 GPREven6 + (sizeof(GPREven6)/sizeof(unsigned)));
410 } else if (Hint.first == ARMRI::RegPairOdd) {
411 if (!STI.isTargetDarwin() && !hasFP(MF)) {
412 if (!STI.isR9Reserved())
413 return std::make_pair(GPROdd1,
414 GPROdd1 + (sizeof(GPROdd1)/sizeof(unsigned)));
416 return std::make_pair(GPROdd4,
417 GPROdd4 + (sizeof(GPROdd4)/sizeof(unsigned)));
418 } else if (FramePtr == ARM::R7) {
419 if (!STI.isR9Reserved())
420 return std::make_pair(GPROdd2,
421 GPROdd2 + (sizeof(GPROdd2)/sizeof(unsigned)));
423 return std::make_pair(GPROdd5,
424 GPROdd5 + (sizeof(GPROdd5)/sizeof(unsigned)));
425 } else { // FramePtr == ARM::R11
426 if (!STI.isR9Reserved())
427 return std::make_pair(GPROdd3,
428 GPROdd3 + (sizeof(GPROdd3)/sizeof(unsigned)));
430 return std::make_pair(GPROdd6,
431 GPROdd6 + (sizeof(GPROdd6)/sizeof(unsigned)));
434 return std::make_pair(RC->allocation_order_begin(MF),
435 RC->allocation_order_end(MF));
438 /// ResolveRegAllocHint - Resolves the specified register allocation hint
439 /// to a physical register. Returns the physical register if it is successful.
441 ARMRegisterInfo::ResolveRegAllocHint(unsigned Type, unsigned Reg,
442 const MachineFunction &MF) const {
443 if (Reg == 0 || !isPhysicalRegister(Reg))
447 else if (Type == (unsigned)ARMRI::RegPairOdd)
449 return getRegisterPairOdd(Reg, MF);
450 else if (Type == (unsigned)ARMRI::RegPairEven)
452 return getRegisterPairEven(Reg, MF);
457 ARMRegisterInfo::requiresRegisterScavenging(const MachineFunction &MF) const {
458 const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
459 return ThumbRegScavenging || !AFI->isThumbFunction();
462 /// hasFP - Return true if the specified function should have a dedicated frame
463 /// pointer register. This is true if the function has variable sized allocas
464 /// or if frame pointer elimination is disabled.
466 bool ARMRegisterInfo::hasFP(const MachineFunction &MF) const {
467 const MachineFrameInfo *MFI = MF.getFrameInfo();
468 return NoFramePointerElim || MFI->hasVarSizedObjects();
471 // hasReservedCallFrame - Under normal circumstances, when a frame pointer is
472 // not required, we reserve argument space for call sites in the function
473 // immediately on entry to the current function. This eliminates the need for
474 // add/sub sp brackets around call sites. Returns true if the call frame is
475 // included as part of the stack frame.
476 bool ARMRegisterInfo::hasReservedCallFrame(MachineFunction &MF) const {
477 const MachineFrameInfo *FFI = MF.getFrameInfo();
478 unsigned CFSize = FFI->getMaxCallFrameSize();
479 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
480 // It's not always a good idea to include the call frame as part of the
481 // stack frame. ARM (especially Thumb) has small immediate offset to
482 // address the stack frame. So a large call frame can cause poor codegen
483 // and may even makes it impossible to scavenge a register.
484 if (AFI->isThumbFunction()) {
485 if (CFSize >= ((1 << 8) - 1) * 4 / 2) // Half of imm8 * 4
488 if (CFSize >= ((1 << 12) - 1) / 2) // Half of imm12
491 return !MF.getFrameInfo()->hasVarSizedObjects();
494 /// emitARMRegPlusImmediate - Emits a series of instructions to materialize
495 /// a destreg = basereg + immediate in ARM code.
497 void emitARMRegPlusImmediate(MachineBasicBlock &MBB,
498 MachineBasicBlock::iterator &MBBI,
499 unsigned DestReg, unsigned BaseReg, int NumBytes,
500 ARMCC::CondCodes Pred, unsigned PredReg,
501 const TargetInstrInfo &TII,
503 bool isSub = NumBytes < 0;
504 if (isSub) NumBytes = -NumBytes;
507 unsigned RotAmt = ARM_AM::getSOImmValRotate(NumBytes);
508 unsigned ThisVal = NumBytes & ARM_AM::rotr32(0xFF, RotAmt);
509 assert(ThisVal && "Didn't extract field correctly");
511 // We will handle these bits from offset, clear them.
512 NumBytes &= ~ThisVal;
514 // Get the properly encoded SOImmVal field.
515 int SOImmVal = ARM_AM::getSOImmVal(ThisVal);
516 assert(SOImmVal != -1 && "Bit extraction didn't work?");
518 // Build the new ADD / SUB.
519 BuildMI(MBB, MBBI, dl, TII.get(isSub ? ARM::SUBri : ARM::ADDri), DestReg)
520 .addReg(BaseReg, RegState::Kill).addImm(SOImmVal)
521 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
526 /// calcNumMI - Returns the number of instructions required to materialize
527 /// the specific add / sub r, c instruction.
528 static unsigned calcNumMI(int Opc, int ExtraOpc, unsigned Bytes,
529 unsigned NumBits, unsigned Scale) {
531 unsigned Chunk = ((1 << NumBits) - 1) * Scale;
533 if (Opc == ARM::tADDrSPi) {
534 unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
538 Scale = 1; // Followed by a number of tADDi8.
539 Chunk = ((1 << NumBits) - 1) * Scale;
542 NumMIs += Bytes / Chunk;
543 if ((Bytes % Chunk) != 0)
550 /// emitThumbRegPlusImmInReg - Emits a series of instructions to materialize
551 /// a destreg = basereg + immediate in Thumb code. Materialize the immediate
552 /// in a register using mov / mvn sequences or load the immediate from a
555 void emitThumbRegPlusImmInReg(MachineBasicBlock &MBB,
556 MachineBasicBlock::iterator &MBBI,
557 unsigned DestReg, unsigned BaseReg,
558 int NumBytes, bool CanChangeCC,
559 const TargetInstrInfo &TII,
560 const ARMRegisterInfo& MRI,
562 bool isHigh = !MRI.isLowRegister(DestReg) ||
563 (BaseReg != 0 && !MRI.isLowRegister(BaseReg));
565 // Subtract doesn't have high register version. Load the negative value
566 // if either base or dest register is a high register. Also, if do not
567 // issue sub as part of the sequence if condition register is to be
569 if (NumBytes < 0 && !isHigh && CanChangeCC) {
571 NumBytes = -NumBytes;
573 unsigned LdReg = DestReg;
574 if (DestReg == ARM::SP) {
575 assert(BaseReg == ARM::SP && "Unexpected!");
577 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVlor2hir), ARM::R12)
578 .addReg(ARM::R3, RegState::Kill);
581 if (NumBytes <= 255 && NumBytes >= 0)
582 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVi8), LdReg).addImm(NumBytes);
583 else if (NumBytes < 0 && NumBytes >= -255) {
584 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVi8), LdReg).addImm(NumBytes);
585 BuildMI(MBB, MBBI, dl, TII.get(ARM::tNEG), LdReg)
586 .addReg(LdReg, RegState::Kill);
588 MRI.emitLoadConstPool(MBB, MBBI, LdReg, NumBytes, ARMCC::AL, 0, &TII,
592 int Opc = (isSub) ? ARM::tSUBrr : (isHigh ? ARM::tADDhirr : ARM::tADDrr);
593 const MachineInstrBuilder MIB = BuildMI(MBB, MBBI, dl,
594 TII.get(Opc), DestReg);
595 if (DestReg == ARM::SP || isSub)
596 MIB.addReg(BaseReg).addReg(LdReg, RegState::Kill);
598 MIB.addReg(LdReg).addReg(BaseReg, RegState::Kill);
599 if (DestReg == ARM::SP)
600 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVhir2lor), ARM::R3)
601 .addReg(ARM::R12, RegState::Kill);
604 /// emitThumbRegPlusImmediate - Emits a series of instructions to materialize
605 /// a destreg = basereg + immediate in Thumb code.
607 void emitThumbRegPlusImmediate(MachineBasicBlock &MBB,
608 MachineBasicBlock::iterator &MBBI,
609 unsigned DestReg, unsigned BaseReg,
610 int NumBytes, const TargetInstrInfo &TII,
611 const ARMRegisterInfo& MRI,
613 bool isSub = NumBytes < 0;
614 unsigned Bytes = (unsigned)NumBytes;
615 if (isSub) Bytes = -NumBytes;
616 bool isMul4 = (Bytes & 3) == 0;
617 bool isTwoAddr = false;
618 bool DstNotEqBase = false;
619 unsigned NumBits = 1;
624 if (DestReg == BaseReg && BaseReg == ARM::SP) {
625 assert(isMul4 && "Thumb sp inc / dec size must be multiple of 4!");
628 Opc = isSub ? ARM::tSUBspi : ARM::tADDspi;
630 } else if (!isSub && BaseReg == ARM::SP) {
633 // r1 = add sp, 100 * 4
637 ExtraOpc = ARM::tADDi3;
646 if (DestReg != BaseReg)
649 Opc = isSub ? ARM::tSUBi8 : ARM::tADDi8;
653 unsigned NumMIs = calcNumMI(Opc, ExtraOpc, Bytes, NumBits, Scale);
654 unsigned Threshold = (DestReg == ARM::SP) ? 3 : 2;
655 if (NumMIs > Threshold) {
656 // This will expand into too many instructions. Load the immediate from a
658 emitThumbRegPlusImmInReg(MBB, MBBI, DestReg, BaseReg, NumBytes, true, TII,
664 if (MRI.isLowRegister(DestReg) && MRI.isLowRegister(BaseReg)) {
665 // If both are low registers, emit DestReg = add BaseReg, max(Imm, 7)
666 unsigned Chunk = (1 << 3) - 1;
667 unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
669 BuildMI(MBB, MBBI, dl,TII.get(isSub ? ARM::tSUBi3 : ARM::tADDi3), DestReg)
670 .addReg(BaseReg, RegState::Kill).addImm(ThisVal);
672 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVr), DestReg)
673 .addReg(BaseReg, RegState::Kill);
678 unsigned Chunk = ((1 << NumBits) - 1) * Scale;
680 unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
683 // Build the new tADD / tSUB.
685 BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
686 .addReg(DestReg).addImm(ThisVal);
688 bool isKill = BaseReg != ARM::SP;
689 BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
690 .addReg(BaseReg, getKillRegState(isKill)).addImm(ThisVal);
693 if (Opc == ARM::tADDrSPi) {
699 Chunk = ((1 << NumBits) - 1) * Scale;
700 Opc = isSub ? ARM::tSUBi8 : ARM::tADDi8;
707 BuildMI(MBB, MBBI, dl, TII.get(ExtraOpc), DestReg)
708 .addReg(DestReg, RegState::Kill)
709 .addImm(((unsigned)NumBytes) & 3);
713 void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
714 int NumBytes, ARMCC::CondCodes Pred, unsigned PredReg,
715 bool isThumb, const TargetInstrInfo &TII,
716 const ARMRegisterInfo& MRI,
719 emitThumbRegPlusImmediate(MBB, MBBI, ARM::SP, ARM::SP, NumBytes, TII,
722 emitARMRegPlusImmediate(MBB, MBBI, ARM::SP, ARM::SP, NumBytes,
723 Pred, PredReg, TII, dl);
726 void ARMRegisterInfo::
727 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
728 MachineBasicBlock::iterator I) const {
729 if (!hasReservedCallFrame(MF)) {
730 // If we have alloca, convert as follows:
731 // ADJCALLSTACKDOWN -> sub, sp, sp, amount
732 // ADJCALLSTACKUP -> add, sp, sp, amount
733 MachineInstr *Old = I;
734 DebugLoc dl = Old->getDebugLoc();
735 unsigned Amount = Old->getOperand(0).getImm();
737 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
738 // We need to keep the stack aligned properly. To do this, we round the
739 // amount of space needed for the outgoing arguments up to the next
740 // alignment boundary.
741 unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
742 Amount = (Amount+Align-1)/Align*Align;
744 // Replace the pseudo instruction with a new instruction...
745 unsigned Opc = Old->getOpcode();
746 bool isThumb = AFI->isThumbFunction();
747 ARMCC::CondCodes Pred = isThumb
748 ? ARMCC::AL : (ARMCC::CondCodes)Old->getOperand(1).getImm();
749 if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) {
750 // Note: PredReg is operand 2 for ADJCALLSTACKDOWN.
751 unsigned PredReg = isThumb ? 0 : Old->getOperand(2).getReg();
752 emitSPUpdate(MBB, I, -Amount, Pred, PredReg, isThumb, TII, *this, dl);
754 // Note: PredReg is operand 3 for ADJCALLSTACKUP.
755 unsigned PredReg = isThumb ? 0 : Old->getOperand(3).getReg();
756 assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP);
757 emitSPUpdate(MBB, I, Amount, Pred, PredReg, isThumb, TII, *this, dl);
764 /// emitThumbConstant - Emit a series of instructions to materialize a
766 static void emitThumbConstant(MachineBasicBlock &MBB,
767 MachineBasicBlock::iterator &MBBI,
768 unsigned DestReg, int Imm,
769 const TargetInstrInfo &TII,
770 const ARMRegisterInfo& MRI,
772 bool isSub = Imm < 0;
773 if (isSub) Imm = -Imm;
775 int Chunk = (1 << 8) - 1;
776 int ThisVal = (Imm > Chunk) ? Chunk : Imm;
778 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVi8), DestReg).addImm(ThisVal);
780 emitThumbRegPlusImmediate(MBB, MBBI, DestReg, DestReg, Imm, TII, MRI, dl);
782 BuildMI(MBB, MBBI, dl, TII.get(ARM::tNEG), DestReg)
783 .addReg(DestReg, RegState::Kill);
786 /// findScratchRegister - Find a 'free' ARM register. If register scavenger
787 /// is not being used, R12 is available. Otherwise, try for a call-clobbered
788 /// register first and then a spilled callee-saved register if that fails.
790 unsigned findScratchRegister(RegScavenger *RS, const TargetRegisterClass *RC,
791 ARMFunctionInfo *AFI) {
792 unsigned Reg = RS ? RS->FindUnusedReg(RC, true) : (unsigned) ARM::R12;
793 assert (!AFI->isThumbFunction());
795 // Try a already spilled CS register.
796 Reg = RS->FindUnusedReg(RC, AFI->getSpilledCSRegisters());
801 void ARMRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
802 int SPAdj, RegScavenger *RS) const{
804 MachineInstr &MI = *II;
805 MachineBasicBlock &MBB = *MI.getParent();
806 MachineFunction &MF = *MBB.getParent();
807 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
808 bool isThumb = AFI->isThumbFunction();
809 DebugLoc dl = MI.getDebugLoc();
811 while (!MI.getOperand(i).isFI()) {
813 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
816 unsigned FrameReg = ARM::SP;
817 int FrameIndex = MI.getOperand(i).getIndex();
818 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
819 MF.getFrameInfo()->getStackSize() + SPAdj;
821 if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
822 Offset -= AFI->getGPRCalleeSavedArea1Offset();
823 else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
824 Offset -= AFI->getGPRCalleeSavedArea2Offset();
825 else if (AFI->isDPRCalleeSavedAreaFrame(FrameIndex))
826 Offset -= AFI->getDPRCalleeSavedAreaOffset();
827 else if (hasFP(MF)) {
828 assert(SPAdj == 0 && "Unexpected");
829 // There is alloca()'s in this function, must reference off the frame
831 FrameReg = getFrameRegister(MF);
832 Offset -= AFI->getFramePtrSpillOffset();
835 unsigned Opcode = MI.getOpcode();
836 const TargetInstrDesc &Desc = MI.getDesc();
837 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
840 // Memory operands in inline assembly always use AddrMode2.
841 if (Opcode == ARM::INLINEASM)
842 AddrMode = ARMII::AddrMode2;
844 if (Opcode == ARM::ADDri) {
845 Offset += MI.getOperand(i+1).getImm();
847 // Turn it into a move.
848 MI.setDesc(TII.get(ARM::MOVr));
849 MI.getOperand(i).ChangeToRegister(FrameReg, false);
850 MI.RemoveOperand(i+1);
852 } else if (Offset < 0) {
855 MI.setDesc(TII.get(ARM::SUBri));
858 // Common case: small offset, fits into instruction.
859 int ImmedOffset = ARM_AM::getSOImmVal(Offset);
860 if (ImmedOffset != -1) {
861 // Replace the FrameIndex with sp / fp
862 MI.getOperand(i).ChangeToRegister(FrameReg, false);
863 MI.getOperand(i+1).ChangeToImmediate(ImmedOffset);
867 // Otherwise, we fallback to common code below to form the imm offset with
868 // a sequence of ADDri instructions. First though, pull as much of the imm
869 // into this ADDri as possible.
870 unsigned RotAmt = ARM_AM::getSOImmValRotate(Offset);
871 unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xFF, RotAmt);
873 // We will handle these bits from offset, clear them.
874 Offset &= ~ThisImmVal;
876 // Get the properly encoded SOImmVal field.
877 int ThisSOImmVal = ARM_AM::getSOImmVal(ThisImmVal);
878 assert(ThisSOImmVal != -1 && "Bit extraction didn't work?");
879 MI.getOperand(i+1).ChangeToImmediate(ThisSOImmVal);
880 } else if (Opcode == ARM::tADDrSPi) {
881 Offset += MI.getOperand(i+1).getImm();
883 // Can't use tADDrSPi if it's based off the frame pointer.
884 unsigned NumBits = 0;
886 if (FrameReg != ARM::SP) {
887 Opcode = ARM::tADDi3;
888 MI.setDesc(TII.get(ARM::tADDi3));
893 assert((Offset & 3) == 0 &&
894 "Thumb add/sub sp, #imm immediate must be multiple of 4!");
898 // Turn it into a move.
899 MI.setDesc(TII.get(ARM::tMOVhir2lor));
900 MI.getOperand(i).ChangeToRegister(FrameReg, false);
901 MI.RemoveOperand(i+1);
905 // Common case: small offset, fits into instruction.
906 unsigned Mask = (1 << NumBits) - 1;
907 if (((Offset / Scale) & ~Mask) == 0) {
908 // Replace the FrameIndex with sp / fp
909 MI.getOperand(i).ChangeToRegister(FrameReg, false);
910 MI.getOperand(i+1).ChangeToImmediate(Offset / Scale);
914 unsigned DestReg = MI.getOperand(0).getReg();
915 unsigned Bytes = (Offset > 0) ? Offset : -Offset;
916 unsigned NumMIs = calcNumMI(Opcode, 0, Bytes, NumBits, Scale);
917 // MI would expand into a large number of instructions. Don't try to
918 // simplify the immediate.
920 emitThumbRegPlusImmediate(MBB, II, DestReg, FrameReg, Offset, TII,
927 // Translate r0 = add sp, imm to
928 // r0 = add sp, 255*4
929 // r0 = add r0, (imm - 255*4)
930 MI.getOperand(i).ChangeToRegister(FrameReg, false);
931 MI.getOperand(i+1).ChangeToImmediate(Mask);
932 Offset = (Offset - Mask * Scale);
933 MachineBasicBlock::iterator NII = next(II);
934 emitThumbRegPlusImmediate(MBB, NII, DestReg, DestReg, Offset, TII,
937 // Translate r0 = add sp, -imm to
938 // r0 = -imm (this is then translated into a series of instructons)
940 emitThumbConstant(MBB, II, DestReg, Offset, TII, *this, dl);
941 MI.setDesc(TII.get(ARM::tADDhirr));
942 MI.getOperand(i).ChangeToRegister(DestReg, false, false, true);
943 MI.getOperand(i+1).ChangeToRegister(FrameReg, false);
949 unsigned NumBits = 0;
952 case ARMII::AddrMode2: {
954 InstrOffs = ARM_AM::getAM2Offset(MI.getOperand(ImmIdx).getImm());
955 if (ARM_AM::getAM2Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
960 case ARMII::AddrMode3: {
962 InstrOffs = ARM_AM::getAM3Offset(MI.getOperand(ImmIdx).getImm());
963 if (ARM_AM::getAM3Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
968 case ARMII::AddrMode5: {
970 InstrOffs = ARM_AM::getAM5Offset(MI.getOperand(ImmIdx).getImm());
971 if (ARM_AM::getAM5Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
977 case ARMII::AddrModeTs: {
979 InstrOffs = MI.getOperand(ImmIdx).getImm();
980 NumBits = (FrameReg == ARM::SP) ? 8 : 5;
985 assert(0 && "Unsupported addressing mode!");
990 Offset += InstrOffs * Scale;
991 assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
992 if (Offset < 0 && !isThumb) {
997 // Common case: small offset, fits into instruction.
998 MachineOperand &ImmOp = MI.getOperand(ImmIdx);
999 int ImmedOffset = Offset / Scale;
1000 unsigned Mask = (1 << NumBits) - 1;
1001 if ((unsigned)Offset <= Mask * Scale) {
1002 // Replace the FrameIndex with sp
1003 MI.getOperand(i).ChangeToRegister(FrameReg, false);
1005 ImmedOffset |= 1 << NumBits;
1006 ImmOp.ChangeToImmediate(ImmedOffset);
1010 bool isThumSpillRestore = Opcode == ARM::tRestore || Opcode == ARM::tSpill;
1011 if (AddrMode == ARMII::AddrModeTs) {
1012 // Thumb tLDRspi, tSTRspi. These will change to instructions that use
1013 // a different base register.
1015 Mask = (1 << NumBits) - 1;
1017 // If this is a thumb spill / restore, we will be using a constpool load to
1018 // materialize the offset.
1019 if (AddrMode == ARMII::AddrModeTs && isThumSpillRestore)
1020 ImmOp.ChangeToImmediate(0);
1022 // Otherwise, it didn't fit. Pull in what we can to simplify the immed.
1023 ImmedOffset = ImmedOffset & Mask;
1025 ImmedOffset |= 1 << NumBits;
1026 ImmOp.ChangeToImmediate(ImmedOffset);
1027 Offset &= ~(Mask*Scale);
1031 // If we get here, the immediate doesn't fit into the instruction. We folded
1032 // as much as possible above, handle the rest, providing a register that is
1034 assert(Offset && "This code isn't needed if offset already handled!");
1037 if (Desc.mayLoad()) {
1038 // Use the destination register to materialize sp + offset.
1039 unsigned TmpReg = MI.getOperand(0).getReg();
1041 if (Opcode == ARM::tRestore) {
1042 if (FrameReg == ARM::SP)
1043 emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg,
1044 Offset, false, TII, *this, dl);
1046 emitLoadConstPool(MBB, II, TmpReg, Offset, ARMCC::AL, 0, &TII,
1051 emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII,
1053 MI.setDesc(TII.get(ARM::tLDR));
1054 MI.getOperand(i).ChangeToRegister(TmpReg, false, false, true);
1056 // Use [reg, reg] addrmode.
1057 MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
1058 else // tLDR has an extra register operand.
1059 MI.addOperand(MachineOperand::CreateReg(0, false));
1060 } else if (Desc.mayStore()) {
1061 // FIXME! This is horrific!!! We need register scavenging.
1062 // Our temporary workaround has marked r3 unavailable. Of course, r3 is
1063 // also a ABI register so it's possible that is is the register that is
1064 // being storing here. If that's the case, we do the following:
1066 // Use r2 to materialize sp + offset
1069 unsigned ValReg = MI.getOperand(0).getReg();
1070 unsigned TmpReg = ARM::R3;
1072 if (ValReg == ARM::R3) {
1073 BuildMI(MBB, II, dl, TII.get(ARM::tMOVlor2hir), ARM::R12)
1074 .addReg(ARM::R2, RegState::Kill);
1077 if (TmpReg == ARM::R3 && AFI->isR3LiveIn())
1078 BuildMI(MBB, II, dl, TII.get(ARM::tMOVlor2hir), ARM::R12)
1079 .addReg(ARM::R3, RegState::Kill);
1080 if (Opcode == ARM::tSpill) {
1081 if (FrameReg == ARM::SP)
1082 emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg,
1083 Offset, false, TII, *this, dl);
1085 emitLoadConstPool(MBB, II, TmpReg, Offset, ARMCC::AL, 0, &TII,
1090 emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII,
1092 MI.setDesc(TII.get(ARM::tSTR));
1093 MI.getOperand(i).ChangeToRegister(TmpReg, false, false, true);
1094 if (UseRR) // Use [reg, reg] addrmode.
1095 MI.addOperand(MachineOperand::CreateReg(FrameReg, false));
1096 else // tSTR has an extra register operand.
1097 MI.addOperand(MachineOperand::CreateReg(0, false));
1099 MachineBasicBlock::iterator NII = next(II);
1100 if (ValReg == ARM::R3)
1101 BuildMI(MBB, NII, dl, TII.get(ARM::tMOVhir2lor), ARM::R2)
1102 .addReg(ARM::R12, RegState::Kill);
1103 if (TmpReg == ARM::R3 && AFI->isR3LiveIn())
1104 BuildMI(MBB, NII, dl, TII.get(ARM::tMOVhir2lor), ARM::R3)
1105 .addReg(ARM::R12, RegState::Kill);
1107 assert(false && "Unexpected opcode!");
1109 // Insert a set of r12 with the full address: r12 = sp + offset
1110 // If the offset we have is too large to fit into the instruction, we need
1111 // to form it with a series of ADDri's. Do this by taking 8-bit chunks
1113 unsigned ScratchReg = findScratchRegister(RS, &ARM::GPRRegClass, AFI);
1114 if (ScratchReg == 0)
1115 // No register is "free". Scavenge a register.
1116 ScratchReg = RS->scavengeRegister(&ARM::GPRRegClass, II, SPAdj);
1117 int PIdx = MI.findFirstPredOperandIdx();
1118 ARMCC::CondCodes Pred = (PIdx == -1)
1119 ? ARMCC::AL : (ARMCC::CondCodes)MI.getOperand(PIdx).getImm();
1120 unsigned PredReg = (PIdx == -1) ? 0 : MI.getOperand(PIdx+1).getReg();
1121 emitARMRegPlusImmediate(MBB, II, ScratchReg, FrameReg,
1122 isSub ? -Offset : Offset, Pred, PredReg, TII, dl);
1123 MI.getOperand(i).ChangeToRegister(ScratchReg, false, false, true);
1127 static unsigned estimateStackSize(MachineFunction &MF, MachineFrameInfo *MFI) {
1128 const MachineFrameInfo *FFI = MF.getFrameInfo();
1130 for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) {
1131 int FixedOff = -FFI->getObjectOffset(i);
1132 if (FixedOff > Offset) Offset = FixedOff;
1134 for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
1135 if (FFI->isDeadObjectIndex(i))
1137 Offset += FFI->getObjectSize(i);
1138 unsigned Align = FFI->getObjectAlignment(i);
1139 // Adjust to alignment boundary
1140 Offset = (Offset+Align-1)/Align*Align;
1142 return (unsigned)Offset;
1146 ARMRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
1147 RegScavenger *RS) const {
1148 // This tells PEI to spill the FP as if it is any other callee-save register
1149 // to take advantage the eliminateFrameIndex machinery. This also ensures it
1150 // is spilled in the order specified by getCalleeSavedRegs() to make it easier
1151 // to combine multiple loads / stores.
1152 bool CanEliminateFrame = true;
1153 bool CS1Spilled = false;
1154 bool LRSpilled = false;
1155 unsigned NumGPRSpills = 0;
1156 SmallVector<unsigned, 4> UnspilledCS1GPRs;
1157 SmallVector<unsigned, 4> UnspilledCS2GPRs;
1158 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1160 // Don't spill FP if the frame can be eliminated. This is determined
1161 // by scanning the callee-save registers to see if any is used.
1162 const unsigned *CSRegs = getCalleeSavedRegs();
1163 const TargetRegisterClass* const *CSRegClasses = getCalleeSavedRegClasses();
1164 for (unsigned i = 0; CSRegs[i]; ++i) {
1165 unsigned Reg = CSRegs[i];
1166 bool Spilled = false;
1167 if (MF.getRegInfo().isPhysRegUsed(Reg)) {
1168 AFI->setCSRegisterIsSpilled(Reg);
1170 CanEliminateFrame = false;
1172 // Check alias registers too.
1173 for (const unsigned *Aliases = getAliasSet(Reg); *Aliases; ++Aliases) {
1174 if (MF.getRegInfo().isPhysRegUsed(*Aliases)) {
1176 CanEliminateFrame = false;
1181 if (CSRegClasses[i] == &ARM::GPRRegClass) {
1185 if (!STI.isTargetDarwin()) {
1192 // Keep track if LR and any of R4, R5, R6, and R7 is spilled.
1207 if (!STI.isTargetDarwin()) {
1208 UnspilledCS1GPRs.push_back(Reg);
1218 UnspilledCS1GPRs.push_back(Reg);
1221 UnspilledCS2GPRs.push_back(Reg);
1228 bool ForceLRSpill = false;
1229 if (!LRSpilled && AFI->isThumbFunction()) {
1230 unsigned FnSize = TII.GetFunctionSizeInBytes(MF);
1231 // Force LR to be spilled if the Thumb function size is > 2048. This enables
1232 // use of BL to implement far jump. If it turns out that it's not needed
1233 // then the branch fix up path will undo it.
1234 if (FnSize >= (1 << 11)) {
1235 CanEliminateFrame = false;
1236 ForceLRSpill = true;
1240 bool ExtraCSSpill = false;
1241 if (!CanEliminateFrame || hasFP(MF)) {
1242 AFI->setHasStackFrame(true);
1244 // If LR is not spilled, but at least one of R4, R5, R6, and R7 is spilled.
1245 // Spill LR as well so we can fold BX_RET to the registers restore (LDM).
1246 if (!LRSpilled && CS1Spilled) {
1247 MF.getRegInfo().setPhysRegUsed(ARM::LR);
1248 AFI->setCSRegisterIsSpilled(ARM::LR);
1250 UnspilledCS1GPRs.erase(std::find(UnspilledCS1GPRs.begin(),
1251 UnspilledCS1GPRs.end(), (unsigned)ARM::LR));
1252 ForceLRSpill = false;
1253 ExtraCSSpill = true;
1256 // Darwin ABI requires FP to point to the stack slot that contains the
1258 if (STI.isTargetDarwin() || hasFP(MF)) {
1259 MF.getRegInfo().setPhysRegUsed(FramePtr);
1263 // If stack and double are 8-byte aligned and we are spilling an odd number
1264 // of GPRs. Spill one extra callee save GPR so we won't have to pad between
1265 // the integer and double callee save areas.
1266 unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
1267 if (TargetAlign == 8 && (NumGPRSpills & 1)) {
1268 if (CS1Spilled && !UnspilledCS1GPRs.empty()) {
1269 for (unsigned i = 0, e = UnspilledCS1GPRs.size(); i != e; ++i) {
1270 unsigned Reg = UnspilledCS1GPRs[i];
1271 // Don't spiil high register if the function is thumb
1272 if (!AFI->isThumbFunction() || isLowRegister(Reg) || Reg == ARM::LR) {
1273 MF.getRegInfo().setPhysRegUsed(Reg);
1274 AFI->setCSRegisterIsSpilled(Reg);
1275 if (!isReservedReg(MF, Reg))
1276 ExtraCSSpill = true;
1280 } else if (!UnspilledCS2GPRs.empty() &&
1281 !AFI->isThumbFunction()) {
1282 unsigned Reg = UnspilledCS2GPRs.front();
1283 MF.getRegInfo().setPhysRegUsed(Reg);
1284 AFI->setCSRegisterIsSpilled(Reg);
1285 if (!isReservedReg(MF, Reg))
1286 ExtraCSSpill = true;
1290 // Estimate if we might need to scavenge a register at some point in order
1291 // to materialize a stack offset. If so, either spill one additiona
1292 // callee-saved register or reserve a special spill slot to facilitate
1293 // register scavenging.
1294 if (RS && !ExtraCSSpill && !AFI->isThumbFunction()) {
1295 MachineFrameInfo *MFI = MF.getFrameInfo();
1296 unsigned Size = estimateStackSize(MF, MFI);
1297 unsigned Limit = (1 << 12) - 1;
1298 for (MachineFunction::iterator BB = MF.begin(),E = MF.end();BB != E; ++BB)
1299 for (MachineBasicBlock::iterator I= BB->begin(); I != BB->end(); ++I) {
1300 for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
1301 if (I->getOperand(i).isFI()) {
1302 unsigned Opcode = I->getOpcode();
1303 const TargetInstrDesc &Desc = TII.get(Opcode);
1304 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
1305 if (AddrMode == ARMII::AddrMode3) {
1306 Limit = (1 << 8) - 1;
1307 goto DoneEstimating;
1308 } else if (AddrMode == ARMII::AddrMode5) {
1309 unsigned ThisLimit = ((1 << 8) - 1) * 4;
1310 if (ThisLimit < Limit)
1316 if (Size >= Limit) {
1317 // If any non-reserved CS register isn't spilled, just spill one or two
1318 // extra. That should take care of it!
1319 unsigned NumExtras = TargetAlign / 4;
1320 SmallVector<unsigned, 2> Extras;
1321 while (NumExtras && !UnspilledCS1GPRs.empty()) {
1322 unsigned Reg = UnspilledCS1GPRs.back();
1323 UnspilledCS1GPRs.pop_back();
1324 if (!isReservedReg(MF, Reg)) {
1325 Extras.push_back(Reg);
1329 while (NumExtras && !UnspilledCS2GPRs.empty()) {
1330 unsigned Reg = UnspilledCS2GPRs.back();
1331 UnspilledCS2GPRs.pop_back();
1332 if (!isReservedReg(MF, Reg)) {
1333 Extras.push_back(Reg);
1337 if (Extras.size() && NumExtras == 0) {
1338 for (unsigned i = 0, e = Extras.size(); i != e; ++i) {
1339 MF.getRegInfo().setPhysRegUsed(Extras[i]);
1340 AFI->setCSRegisterIsSpilled(Extras[i]);
1343 // Reserve a slot closest to SP or frame pointer.
1344 const TargetRegisterClass *RC = &ARM::GPRRegClass;
1345 RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
1346 RC->getAlignment()));
1353 MF.getRegInfo().setPhysRegUsed(ARM::LR);
1354 AFI->setCSRegisterIsSpilled(ARM::LR);
1355 AFI->setLRIsSpilledForFarJump(true);
1359 /// Move iterator pass the next bunch of callee save load / store ops for
1360 /// the particular spill area (1: integer area 1, 2: integer area 2,
1361 /// 3: fp area, 0: don't care).
1362 static void movePastCSLoadStoreOps(MachineBasicBlock &MBB,
1363 MachineBasicBlock::iterator &MBBI,
1364 int Opc, unsigned Area,
1365 const ARMSubtarget &STI) {
1366 while (MBBI != MBB.end() &&
1367 MBBI->getOpcode() == Opc && MBBI->getOperand(1).isFI()) {
1370 unsigned Category = 0;
1371 switch (MBBI->getOperand(0).getReg()) {
1372 case ARM::R4: case ARM::R5: case ARM::R6: case ARM::R7:
1376 case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11:
1377 Category = STI.isTargetDarwin() ? 2 : 1;
1379 case ARM::D8: case ARM::D9: case ARM::D10: case ARM::D11:
1380 case ARM::D12: case ARM::D13: case ARM::D14: case ARM::D15:
1387 if (Done || Category != Area)
1395 void ARMRegisterInfo::emitPrologue(MachineFunction &MF) const {
1396 MachineBasicBlock &MBB = MF.front();
1397 MachineBasicBlock::iterator MBBI = MBB.begin();
1398 MachineFrameInfo *MFI = MF.getFrameInfo();
1399 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1400 bool isThumb = AFI->isThumbFunction();
1401 unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
1402 unsigned NumBytes = MFI->getStackSize();
1403 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
1404 DebugLoc dl = (MBBI != MBB.end() ?
1405 MBBI->getDebugLoc() : DebugLoc::getUnknownLoc());
1408 // Check if R3 is live in. It might have to be used as a scratch register.
1409 for (MachineRegisterInfo::livein_iterator I =MF.getRegInfo().livein_begin(),
1410 E = MF.getRegInfo().livein_end(); I != E; ++I) {
1411 if (I->first == ARM::R3) {
1412 AFI->setR3IsLiveIn(true);
1417 // Thumb add/sub sp, imm8 instructions implicitly multiply the offset by 4.
1418 NumBytes = (NumBytes + 3) & ~3;
1419 MFI->setStackSize(NumBytes);
1422 // Determine the sizes of each callee-save spill areas and record which frame
1423 // belongs to which callee-save spill areas.
1424 unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
1425 int FramePtrSpillFI = 0;
1428 emitSPUpdate(MBB, MBBI, -VARegSaveSize, ARMCC::AL, 0, isThumb, TII,
1431 if (!AFI->hasStackFrame()) {
1433 emitSPUpdate(MBB, MBBI, -NumBytes, ARMCC::AL, 0, isThumb, TII, *this, dl);
1437 for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
1438 unsigned Reg = CSI[i].getReg();
1439 int FI = CSI[i].getFrameIdx();
1446 if (Reg == FramePtr)
1447 FramePtrSpillFI = FI;
1448 AFI->addGPRCalleeSavedArea1Frame(FI);
1455 if (Reg == FramePtr)
1456 FramePtrSpillFI = FI;
1457 if (STI.isTargetDarwin()) {
1458 AFI->addGPRCalleeSavedArea2Frame(FI);
1461 AFI->addGPRCalleeSavedArea1Frame(FI);
1466 AFI->addDPRCalleeSavedAreaFrame(FI);
1472 // Build the new SUBri to adjust SP for integer callee-save spill area 1.
1473 emitSPUpdate(MBB, MBBI, -GPRCS1Size, ARMCC::AL, 0, isThumb, TII, *this, dl);
1474 movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, 1, STI);
1475 } else if (MBBI != MBB.end() && MBBI->getOpcode() == ARM::tPUSH) {
1477 if (MBBI != MBB.end())
1478 dl = MBBI->getDebugLoc();
1481 // Darwin ABI requires FP to point to the stack slot that contains the
1483 if (STI.isTargetDarwin() || hasFP(MF)) {
1484 MachineInstrBuilder MIB =
1485 BuildMI(MBB, MBBI, dl, TII.get(isThumb ? ARM::tADDrSPi : ARM::ADDri),
1487 .addFrameIndex(FramePtrSpillFI).addImm(0);
1488 if (!isThumb) AddDefaultCC(AddDefaultPred(MIB));
1492 // Build the new SUBri to adjust SP for integer callee-save spill area 2.
1493 emitSPUpdate(MBB, MBBI, -GPRCS2Size, ARMCC::AL, 0, false, TII, *this, dl);
1495 // Build the new SUBri to adjust SP for FP callee-save spill area.
1496 movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, 2, STI);
1497 emitSPUpdate(MBB, MBBI, -DPRCSSize, ARMCC::AL, 0, false, TII, *this, dl);
1500 // Determine starting offsets of spill areas.
1501 unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
1502 unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
1503 unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
1504 AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) + NumBytes);
1505 AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
1506 AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
1507 AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
1509 NumBytes = DPRCSOffset;
1511 // Insert it after all the callee-save spills.
1513 movePastCSLoadStoreOps(MBB, MBBI, ARM::FSTD, 3, STI);
1514 emitSPUpdate(MBB, MBBI, -NumBytes, ARMCC::AL, 0, isThumb, TII, *this, dl);
1517 if(STI.isTargetELF() && hasFP(MF)) {
1518 MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
1519 AFI->getFramePtrSpillOffset());
1522 AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
1523 AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
1524 AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
1527 static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
1528 for (unsigned i = 0; CSRegs[i]; ++i)
1529 if (Reg == CSRegs[i])
1534 static bool isCSRestore(MachineInstr *MI, const unsigned *CSRegs) {
1535 return ((MI->getOpcode() == ARM::FLDD ||
1536 MI->getOpcode() == ARM::LDR ||
1537 MI->getOpcode() == ARM::tRestore) &&
1538 MI->getOperand(1).isFI() &&
1539 isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs));
1542 void ARMRegisterInfo::emitEpilogue(MachineFunction &MF,
1543 MachineBasicBlock &MBB) const {
1544 MachineBasicBlock::iterator MBBI = prior(MBB.end());
1545 assert((MBBI->getOpcode() == ARM::BX_RET ||
1546 MBBI->getOpcode() == ARM::tBX_RET ||
1547 MBBI->getOpcode() == ARM::tPOP_RET) &&
1548 "Can only insert epilog into returning blocks");
1549 DebugLoc dl = MBBI->getDebugLoc();
1550 MachineFrameInfo *MFI = MF.getFrameInfo();
1551 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1552 bool isThumb = AFI->isThumbFunction();
1553 unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
1554 int NumBytes = (int)MFI->getStackSize();
1556 if (!AFI->hasStackFrame()) {
1558 emitSPUpdate(MBB, MBBI, NumBytes, ARMCC::AL, 0, isThumb, TII, *this, dl);
1560 // Unwind MBBI to point to first LDR / FLDD.
1561 const unsigned *CSRegs = getCalleeSavedRegs();
1562 if (MBBI != MBB.begin()) {
1565 while (MBBI != MBB.begin() && isCSRestore(MBBI, CSRegs));
1566 if (!isCSRestore(MBBI, CSRegs))
1570 // Move SP to start of FP callee save spill area.
1571 NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
1572 AFI->getGPRCalleeSavedArea2Size() +
1573 AFI->getDPRCalleeSavedAreaSize());
1576 NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
1577 // Reset SP based on frame pointer only if the stack frame extends beyond
1578 // frame pointer stack slot or target is ELF and the function has FP.
1580 emitThumbRegPlusImmediate(MBB, MBBI, ARM::SP, FramePtr, -NumBytes,
1583 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVlor2hir), ARM::SP)
1586 if (MBBI->getOpcode() == ARM::tBX_RET &&
1587 &MBB.front() != MBBI &&
1588 prior(MBBI)->getOpcode() == ARM::tPOP) {
1589 MachineBasicBlock::iterator PMBBI = prior(MBBI);
1590 emitSPUpdate(MBB, PMBBI, NumBytes, ARMCC::AL, 0, isThumb, TII,
1593 emitSPUpdate(MBB, MBBI, NumBytes, ARMCC::AL, 0, isThumb, TII,
1597 // Darwin ABI requires FP to point to the stack slot that contains the
1599 if ((STI.isTargetDarwin() && NumBytes) || hasFP(MF)) {
1600 NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
1601 // Reset SP based on frame pointer only if the stack frame extends beyond
1602 // frame pointer stack slot or target is ELF and the function has FP.
1603 if (AFI->getGPRCalleeSavedArea2Size() ||
1604 AFI->getDPRCalleeSavedAreaSize() ||
1605 AFI->getDPRCalleeSavedAreaOffset()||
1608 BuildMI(MBB, MBBI, dl, TII.get(ARM::SUBri), ARM::SP).addReg(FramePtr)
1610 .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
1612 BuildMI(MBB, MBBI, dl, TII.get(ARM::MOVr), ARM::SP).addReg(FramePtr)
1613 .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
1615 } else if (NumBytes) {
1616 emitSPUpdate(MBB, MBBI, NumBytes, ARMCC::AL, 0, false, TII, *this, dl);
1619 // Move SP to start of integer callee save spill area 2.
1620 movePastCSLoadStoreOps(MBB, MBBI, ARM::FLDD, 3, STI);
1621 emitSPUpdate(MBB, MBBI, AFI->getDPRCalleeSavedAreaSize(), ARMCC::AL, 0,
1622 false, TII, *this, dl);
1624 // Move SP to start of integer callee save spill area 1.
1625 movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, 2, STI);
1626 emitSPUpdate(MBB, MBBI, AFI->getGPRCalleeSavedArea2Size(), ARMCC::AL, 0,
1627 false, TII, *this, dl);
1629 // Move SP to SP upon entry to the function.
1630 movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, 1, STI);
1631 emitSPUpdate(MBB, MBBI, AFI->getGPRCalleeSavedArea1Size(), ARMCC::AL, 0,
1632 false, TII, *this, dl);
1636 if (VARegSaveSize) {
1638 // Epilogue for vararg functions: pop LR to R3 and branch off it.
1639 // FIXME: Verify this is still ok when R3 is no longer being reserved.
1640 BuildMI(MBB, MBBI, dl, TII.get(ARM::tPOP)).addReg(ARM::R3);
1642 emitSPUpdate(MBB, MBBI, VARegSaveSize, ARMCC::AL, 0, isThumb, TII,
1646 BuildMI(MBB, MBBI, dl, TII.get(ARM::tBX_RET_vararg)).addReg(ARM::R3);
1652 unsigned ARMRegisterInfo::getRARegister() const {
1656 unsigned ARMRegisterInfo::getFrameRegister(MachineFunction &MF) const {
1657 if (STI.isTargetDarwin() || hasFP(MF))
1658 return (STI.useThumbBacktraces() || STI.isThumb()) ? ARM::R7 : ARM::R11;
1663 unsigned ARMRegisterInfo::getEHExceptionRegister() const {
1664 assert(0 && "What is the exception register");
1668 unsigned ARMRegisterInfo::getEHHandlerRegister() const {
1669 assert(0 && "What is the exception handler register");
1673 int ARMRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
1674 return ARMGenRegisterInfo::getDwarfRegNumFull(RegNum, 0);
1677 unsigned ARMRegisterInfo::getRegisterPairEven(unsigned Reg,
1678 const MachineFunction &MF) const {
1681 // Return 0 if either register of the pair is a special register.
1683 case ARM::R0: case ARM::R1:
1685 case ARM::R2: case ARM::R3:
1687 return STI.isThumb() ? 0 : ARM::R2;
1688 case ARM::R4: case ARM::R5:
1690 case ARM::R6: case ARM::R7:
1691 return isReservedReg(MF, ARM::R7) ? 0 : ARM::R6;
1692 case ARM::R8: case ARM::R9:
1693 return isReservedReg(MF, ARM::R9) ? 0 :ARM::R8;
1694 case ARM::R10: case ARM::R11:
1695 return isReservedReg(MF, ARM::R11) ? 0 : ARM::R10;
1697 case ARM::S0: case ARM::S1:
1699 case ARM::S2: case ARM::S3:
1701 case ARM::S4: case ARM::S5:
1703 case ARM::S6: case ARM::S7:
1705 case ARM::S8: case ARM::S9:
1707 case ARM::S10: case ARM::S11:
1709 case ARM::S12: case ARM::S13:
1711 case ARM::S14: case ARM::S15:
1713 case ARM::S16: case ARM::S17:
1715 case ARM::S18: case ARM::S19:
1717 case ARM::S20: case ARM::S21:
1719 case ARM::S22: case ARM::S23:
1721 case ARM::S24: case ARM::S25:
1723 case ARM::S26: case ARM::S27:
1725 case ARM::S28: case ARM::S29:
1727 case ARM::S30: case ARM::S31:
1730 case ARM::D0: case ARM::D1:
1732 case ARM::D2: case ARM::D3:
1734 case ARM::D4: case ARM::D5:
1736 case ARM::D6: case ARM::D7:
1738 case ARM::D8: case ARM::D9:
1740 case ARM::D10: case ARM::D11:
1742 case ARM::D12: case ARM::D13:
1744 case ARM::D14: case ARM::D15:
1751 unsigned ARMRegisterInfo::getRegisterPairOdd(unsigned Reg,
1752 const MachineFunction &MF) const {
1755 // Return 0 if either register of the pair is a special register.
1757 case ARM::R0: case ARM::R1:
1759 case ARM::R2: case ARM::R3:
1761 return STI.isThumb() ? 0 : ARM::R3;
1762 case ARM::R4: case ARM::R5:
1764 case ARM::R6: case ARM::R7:
1765 return isReservedReg(MF, ARM::R7) ? 0 : ARM::R7;
1766 case ARM::R8: case ARM::R9:
1767 return isReservedReg(MF, ARM::R9) ? 0 :ARM::R9;
1768 case ARM::R10: case ARM::R11:
1769 return isReservedReg(MF, ARM::R11) ? 0 : ARM::R11;
1771 case ARM::S0: case ARM::S1:
1773 case ARM::S2: case ARM::S3:
1775 case ARM::S4: case ARM::S5:
1777 case ARM::S6: case ARM::S7:
1779 case ARM::S8: case ARM::S9:
1781 case ARM::S10: case ARM::S11:
1783 case ARM::S12: case ARM::S13:
1785 case ARM::S14: case ARM::S15:
1787 case ARM::S16: case ARM::S17:
1789 case ARM::S18: case ARM::S19:
1791 case ARM::S20: case ARM::S21:
1793 case ARM::S22: case ARM::S23:
1795 case ARM::S24: case ARM::S25:
1797 case ARM::S26: case ARM::S27:
1799 case ARM::S28: case ARM::S29:
1801 case ARM::S30: case ARM::S31:
1804 case ARM::D0: case ARM::D1:
1806 case ARM::D2: case ARM::D3:
1808 case ARM::D4: case ARM::D5:
1810 case ARM::D6: case ARM::D7:
1812 case ARM::D8: case ARM::D9:
1814 case ARM::D10: case ARM::D11:
1816 case ARM::D12: case ARM::D13:
1818 case ARM::D14: case ARM::D15:
1825 #include "ARMGenRegisterInfo.inc"