1 //===- ARMRegisterInfo.cpp - ARM Register Information -----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the "Instituto Nokia de Tecnologia" and
6 // is distributed under the University of Illinois Open Source
7 // License. See LICENSE.TXT for details.
9 //===----------------------------------------------------------------------===//
11 // This file contains the ARM implementation of the MRegisterInfo class.
13 //===----------------------------------------------------------------------===//
16 #include "ARMAddressingModes.h"
17 #include "ARMInstrInfo.h"
18 #include "ARMMachineFunctionInfo.h"
19 #include "ARMRegisterInfo.h"
20 #include "ARMSubtarget.h"
21 #include "llvm/Constants.h"
22 #include "llvm/DerivedTypes.h"
23 #include "llvm/CodeGen/MachineConstantPool.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineInstrBuilder.h"
27 #include "llvm/CodeGen/MachineLocation.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 ARMRegisterInfo::ARMRegisterInfo(const TargetInstrInfo &tii,
85 const ARMSubtarget &sti)
86 : ARMGenRegisterInfo(ARM::ADJCALLSTACKDOWN, ARM::ADJCALLSTACKUP),
88 FramePtr((STI.useThumbBacktraces() || STI.isThumb()) ? ARM::R7 : ARM::R11) {
91 bool ARMRegisterInfo::spillCalleeSavedRegisters(MachineBasicBlock &MBB,
92 MachineBasicBlock::iterator MI,
93 const std::vector<CalleeSavedInfo> &CSI) const {
94 MachineFunction &MF = *MBB.getParent();
95 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
96 if (!AFI->isThumbFunction() || CSI.empty())
99 MachineInstrBuilder MIB = BuildMI(MBB, MI, TII.get(ARM::tPUSH));
100 for (unsigned i = CSI.size(); i != 0; --i) {
101 unsigned Reg = CSI[i-1].getReg();
102 // Add the callee-saved register as live-in. It's killed at the spill.
104 MIB.addReg(Reg, false/*isDef*/,false/*isImp*/,true/*isKill*/);
109 bool ARMRegisterInfo::restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
110 MachineBasicBlock::iterator MI,
111 const std::vector<CalleeSavedInfo> &CSI) const {
112 MachineFunction &MF = *MBB.getParent();
113 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
114 if (!AFI->isThumbFunction() || CSI.empty())
117 bool isVarArg = AFI->getVarArgsRegSaveSize() > 0;
118 MachineInstr *PopMI = new MachineInstr(TII.get(ARM::tPOP));
119 MBB.insert(MI, PopMI);
120 for (unsigned i = CSI.size(); i != 0; --i) {
121 unsigned Reg = CSI[i-1].getReg();
122 if (Reg == ARM::LR) {
123 // Special epilogue for vararg functions. See emitEpilogue
127 PopMI->setInstrDescriptor(TII.get(ARM::tPOP_RET));
130 PopMI->addRegOperand(Reg, true);
136 const MachineInstrBuilder &AddDefaultPred(const MachineInstrBuilder &MIB) {
137 return MIB.addImm((int64_t)ARMCC::AL).addReg(0);
141 const MachineInstrBuilder &AddDefaultCC(const MachineInstrBuilder &MIB) {
142 return MIB.addReg(0);
145 static const MachineInstrBuilder &ARMInstrAddOperand(MachineInstrBuilder &MIB,
146 MachineOperand &MO) {
148 MIB = MIB.addReg(MO.getReg(), MO.isDef(), MO.isImplicit());
149 else if (MO.isImmediate())
150 MIB = MIB.addImm(MO.getImm());
151 else if (MO.isFrameIndex())
152 MIB = MIB.addFrameIndex(MO.getFrameIndex());
154 assert(0 && "Unknown operand for ARMInstrAddOperand!");
159 void ARMRegisterInfo::
160 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
161 unsigned SrcReg, bool isKill, int FI,
162 const TargetRegisterClass *RC) const {
163 if (RC == ARM::GPRRegisterClass) {
164 MachineFunction &MF = *MBB.getParent();
165 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
166 if (AFI->isThumbFunction())
167 BuildMI(MBB, I, TII.get(ARM::tSpill)).addReg(SrcReg, false, false, isKill)
168 .addFrameIndex(FI).addImm(0);
170 AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::STR))
171 .addReg(SrcReg, false, false, isKill)
172 .addFrameIndex(FI).addReg(0).addImm(0));
173 } else if (RC == ARM::DPRRegisterClass) {
174 AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::FSTD))
175 .addReg(SrcReg, false, false, isKill)
176 .addFrameIndex(FI).addImm(0));
178 assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
179 AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::FSTS))
180 .addReg(SrcReg, false, false, isKill)
181 .addFrameIndex(FI).addImm(0));
185 void ARMRegisterInfo::storeRegToAddr(MachineFunction &MF, unsigned SrcReg,
187 SmallVectorImpl<MachineOperand> &Addr,
188 const TargetRegisterClass *RC,
189 SmallVectorImpl<MachineInstr*> &NewMIs) const {
191 if (RC == ARM::GPRRegisterClass) {
192 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
193 if (AFI->isThumbFunction()) {
194 Opc = Addr[0].isFrameIndex() ? ARM::tSpill : ARM::tSTR;
195 MachineInstrBuilder MIB =
196 BuildMI(TII.get(Opc)).addReg(SrcReg, false, false, isKill);
197 for (unsigned i = 0, e = Addr.size(); i != e; ++i)
198 MIB = ARMInstrAddOperand(MIB, Addr[i]);
199 NewMIs.push_back(MIB);
203 } else if (RC == ARM::DPRRegisterClass) {
206 assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
210 MachineInstrBuilder MIB =
211 BuildMI(TII.get(Opc)).addReg(SrcReg, false, false, isKill);
212 for (unsigned i = 0, e = Addr.size(); i != e; ++i)
213 MIB = ARMInstrAddOperand(MIB, Addr[i]);
215 NewMIs.push_back(MIB);
219 void ARMRegisterInfo::
220 loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
221 unsigned DestReg, int FI,
222 const TargetRegisterClass *RC) const {
223 if (RC == ARM::GPRRegisterClass) {
224 MachineFunction &MF = *MBB.getParent();
225 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
226 if (AFI->isThumbFunction())
227 BuildMI(MBB, I, TII.get(ARM::tRestore), DestReg)
228 .addFrameIndex(FI).addImm(0);
230 AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::LDR), DestReg)
231 .addFrameIndex(FI).addReg(0).addImm(0));
232 } else if (RC == ARM::DPRRegisterClass) {
233 AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::FLDD), DestReg)
234 .addFrameIndex(FI).addImm(0));
236 assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
237 AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::FLDS), DestReg)
238 .addFrameIndex(FI).addImm(0));
242 void ARMRegisterInfo::loadRegFromAddr(MachineFunction &MF, unsigned DestReg,
243 SmallVectorImpl<MachineOperand> &Addr,
244 const TargetRegisterClass *RC,
245 SmallVectorImpl<MachineInstr*> &NewMIs) const {
247 if (RC == ARM::GPRRegisterClass) {
248 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
249 if (AFI->isThumbFunction()) {
250 Opc = Addr[0].isFrameIndex() ? ARM::tRestore : ARM::tLDR;
251 MachineInstrBuilder MIB = BuildMI(TII.get(Opc), DestReg);
252 for (unsigned i = 0, e = Addr.size(); i != e; ++i)
253 MIB = ARMInstrAddOperand(MIB, Addr[i]);
254 NewMIs.push_back(MIB);
258 } else if (RC == ARM::DPRRegisterClass) {
261 assert(RC == ARM::SPRRegisterClass && "Unknown regclass!");
265 MachineInstrBuilder MIB = BuildMI(TII.get(Opc), DestReg);
266 for (unsigned i = 0, e = Addr.size(); i != e; ++i)
267 MIB = ARMInstrAddOperand(MIB, Addr[i]);
269 NewMIs.push_back(MIB);
273 void ARMRegisterInfo::copyRegToReg(MachineBasicBlock &MBB,
274 MachineBasicBlock::iterator I,
275 unsigned DestReg, unsigned SrcReg,
276 const TargetRegisterClass *DestRC,
277 const TargetRegisterClass *SrcRC) const {
278 if (DestRC != SrcRC) {
279 cerr << "Not yet supported!";
283 if (DestRC == ARM::GPRRegisterClass) {
284 MachineFunction &MF = *MBB.getParent();
285 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
286 if (AFI->isThumbFunction())
287 BuildMI(MBB, I, TII.get(ARM::tMOVr), DestReg).addReg(SrcReg);
289 AddDefaultCC(AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::MOVr), DestReg)
291 } else if (DestRC == ARM::SPRRegisterClass)
292 AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::FCPYS), DestReg)
294 else if (DestRC == ARM::DPRRegisterClass)
295 AddDefaultPred(BuildMI(MBB, I, TII.get(ARM::FCPYD), DestReg)
301 /// emitLoadConstPool - Emits a load from constpool to materialize the
302 /// specified immediate.
303 static void emitLoadConstPool(MachineBasicBlock &MBB,
304 MachineBasicBlock::iterator &MBBI,
305 unsigned DestReg, int Val,
306 ARMCC::CondCodes Pred, unsigned PredReg,
307 const TargetInstrInfo &TII, bool isThumb) {
308 MachineFunction &MF = *MBB.getParent();
309 MachineConstantPool *ConstantPool = MF.getConstantPool();
310 Constant *C = ConstantInt::get(Type::Int32Ty, Val);
311 unsigned Idx = ConstantPool->getConstantPoolIndex(C, 2);
313 BuildMI(MBB, MBBI, TII.get(ARM::tLDRcp), DestReg).addConstantPoolIndex(Idx);
315 BuildMI(MBB, MBBI, TII.get(ARM::LDRcp), DestReg).addConstantPoolIndex(Idx)
316 .addReg(0).addImm(0).addImm((unsigned)Pred).addReg(PredReg);
319 void ARMRegisterInfo::reMaterialize(MachineBasicBlock &MBB,
320 MachineBasicBlock::iterator I,
322 const MachineInstr *Orig) const {
323 if (Orig->getOpcode() == ARM::MOVi2pieces) {
324 emitLoadConstPool(MBB, I, DestReg,
325 Orig->getOperand(1).getImmedValue(),
326 (ARMCC::CondCodes)Orig->getOperand(2).getImmedValue(),
327 Orig->getOperand(3).getReg(),
332 MachineInstr *MI = Orig->clone();
333 MI->getOperand(0).setReg(DestReg);
337 /// isLowRegister - Returns true if the register is low register r0-r7.
339 static bool isLowRegister(unsigned Reg) {
342 case R0: case R1: case R2: case R3:
343 case R4: case R5: case R6: case R7:
350 MachineInstr *ARMRegisterInfo::foldMemoryOperand(MachineInstr *MI,
351 SmallVectorImpl<unsigned> &Ops,
353 if (Ops.size() != 1) return NULL;
355 unsigned OpNum = Ops[0];
356 unsigned Opc = MI->getOpcode();
357 MachineInstr *NewMI = NULL;
361 if (MI->getOperand(4).getReg() == ARM::CPSR)
362 // If it is updating CPSR, then it cannot be foled.
364 unsigned Pred = MI->getOperand(2).getImmedValue();
365 unsigned PredReg = MI->getOperand(3).getReg();
366 if (OpNum == 0) { // move -> store
367 unsigned SrcReg = MI->getOperand(1).getReg();
368 NewMI = BuildMI(TII.get(ARM::STR)).addReg(SrcReg).addFrameIndex(FI)
369 .addReg(0).addImm(0).addImm(Pred).addReg(PredReg);
370 } else { // move -> load
371 unsigned DstReg = MI->getOperand(0).getReg();
372 NewMI = BuildMI(TII.get(ARM::LDR), DstReg).addFrameIndex(FI).addReg(0)
373 .addImm(0).addImm(Pred).addReg(PredReg);
378 if (OpNum == 0) { // move -> store
379 unsigned SrcReg = MI->getOperand(1).getReg();
380 if (isPhysicalRegister(SrcReg) && !isLowRegister(SrcReg))
381 // tSpill cannot take a high register operand.
383 NewMI = BuildMI(TII.get(ARM::tSpill)).addReg(SrcReg).addFrameIndex(FI)
385 } else { // move -> load
386 unsigned DstReg = MI->getOperand(0).getReg();
387 if (isPhysicalRegister(DstReg) && !isLowRegister(DstReg))
388 // tRestore cannot target a high register operand.
390 NewMI = BuildMI(TII.get(ARM::tRestore), DstReg).addFrameIndex(FI)
396 unsigned Pred = MI->getOperand(2).getImmedValue();
397 unsigned PredReg = MI->getOperand(3).getReg();
398 if (OpNum == 0) { // move -> store
399 unsigned SrcReg = MI->getOperand(1).getReg();
400 NewMI = BuildMI(TII.get(ARM::FSTS)).addReg(SrcReg).addFrameIndex(FI)
401 .addImm(0).addImm(Pred).addReg(PredReg);
402 } else { // move -> load
403 unsigned DstReg = MI->getOperand(0).getReg();
404 NewMI = BuildMI(TII.get(ARM::FLDS), DstReg).addFrameIndex(FI)
405 .addImm(0).addImm(Pred).addReg(PredReg);
410 unsigned Pred = MI->getOperand(2).getImmedValue();
411 unsigned PredReg = MI->getOperand(3).getReg();
412 if (OpNum == 0) { // move -> store
413 unsigned SrcReg = MI->getOperand(1).getReg();
414 NewMI = BuildMI(TII.get(ARM::FSTD)).addReg(SrcReg).addFrameIndex(FI)
415 .addImm(0).addImm(Pred).addReg(PredReg);
416 } else { // move -> load
417 unsigned DstReg = MI->getOperand(0).getReg();
418 NewMI = BuildMI(TII.get(ARM::FLDD), DstReg).addFrameIndex(FI)
419 .addImm(0).addImm(Pred).addReg(PredReg);
426 NewMI->copyKillDeadInfo(MI);
430 bool ARMRegisterInfo::canFoldMemoryOperand(MachineInstr *MI,
431 SmallVectorImpl<unsigned> &Ops) const {
432 if (Ops.size() != 1) return 0;
434 unsigned OpNum = Ops[0];
435 unsigned Opc = MI->getOpcode();
439 // If it is updating CPSR, then it cannot be foled.
440 return MI->getOperand(4).getReg() != ARM::CPSR;
442 if (OpNum == 0) { // move -> store
443 unsigned SrcReg = MI->getOperand(1).getReg();
444 if (isPhysicalRegister(SrcReg) && !isLowRegister(SrcReg))
445 // tSpill cannot take a high register operand.
447 } else { // move -> load
448 unsigned DstReg = MI->getOperand(0).getReg();
449 if (isPhysicalRegister(DstReg) && !isLowRegister(DstReg))
450 // tRestore cannot target a high register operand.
464 ARMRegisterInfo::getCalleeSavedRegs(const MachineFunction *MF) const {
465 static const unsigned CalleeSavedRegs[] = {
466 ARM::LR, ARM::R11, ARM::R10, ARM::R9, ARM::R8,
467 ARM::R7, ARM::R6, ARM::R5, ARM::R4,
469 ARM::D15, ARM::D14, ARM::D13, ARM::D12,
470 ARM::D11, ARM::D10, ARM::D9, ARM::D8,
474 static const unsigned DarwinCalleeSavedRegs[] = {
475 ARM::LR, ARM::R7, ARM::R6, ARM::R5, ARM::R4,
476 ARM::R11, ARM::R10, ARM::R9, ARM::R8,
478 ARM::D15, ARM::D14, ARM::D13, ARM::D12,
479 ARM::D11, ARM::D10, ARM::D9, ARM::D8,
482 return STI.isTargetDarwin() ? DarwinCalleeSavedRegs : CalleeSavedRegs;
485 const TargetRegisterClass* const *
486 ARMRegisterInfo::getCalleeSavedRegClasses(const MachineFunction *MF) const {
487 static const TargetRegisterClass * const CalleeSavedRegClasses[] = {
488 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
489 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
490 &ARM::GPRRegClass, &ARM::GPRRegClass, &ARM::GPRRegClass,
492 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
493 &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass, &ARM::DPRRegClass,
496 return CalleeSavedRegClasses;
499 BitVector ARMRegisterInfo::getReservedRegs(const MachineFunction &MF) const {
500 // FIXME: avoid re-calculating this everytime.
501 BitVector Reserved(getNumRegs());
502 Reserved.set(ARM::SP);
503 Reserved.set(ARM::PC);
504 if (STI.isTargetDarwin() || hasFP(MF))
505 Reserved.set(FramePtr);
506 // Some targets reserve R9.
507 if (STI.isR9Reserved())
508 Reserved.set(ARM::R9);
513 ARMRegisterInfo::isReservedReg(const MachineFunction &MF, unsigned Reg) const {
521 if (FramePtr == Reg && (STI.isTargetDarwin() || hasFP(MF)))
525 return STI.isR9Reserved();
532 ARMRegisterInfo::requiresRegisterScavenging(const MachineFunction &MF) const {
533 const ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
534 return ThumbRegScavenging || !AFI->isThumbFunction();
537 /// hasFP - Return true if the specified function should have a dedicated frame
538 /// pointer register. This is true if the function has variable sized allocas
539 /// or if frame pointer elimination is disabled.
541 bool ARMRegisterInfo::hasFP(const MachineFunction &MF) const {
542 return NoFramePointerElim || MF.getFrameInfo()->hasVarSizedObjects();
545 // hasReservedCallFrame - Under normal circumstances, when a frame pointer is
546 // not required, we reserve argument space for call sites in the function
547 // immediately on entry to the current function. This eliminates the need for
548 // add/sub sp brackets around call sites. Returns true if the call frame is
549 // included as part of the stack frame.
550 bool ARMRegisterInfo::hasReservedCallFrame(MachineFunction &MF) const {
551 const MachineFrameInfo *FFI = MF.getFrameInfo();
552 unsigned CFSize = FFI->getMaxCallFrameSize();
553 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
554 // It's not always a good idea to include the call frame as part of the
555 // stack frame. ARM (especially Thumb) has small immediate offset to
556 // address the stack frame. So a large call frame can cause poor codegen
557 // and may even makes it impossible to scavenge a register.
558 if (AFI->isThumbFunction()) {
559 if (CFSize >= ((1 << 8) - 1) * 4 / 2) // Half of imm8 * 4
562 if (CFSize >= ((1 << 12) - 1) / 2) // Half of imm12
565 return !MF.getFrameInfo()->hasVarSizedObjects();
568 /// emitARMRegPlusImmediate - Emits a series of instructions to materialize
569 /// a destreg = basereg + immediate in ARM code.
571 void emitARMRegPlusImmediate(MachineBasicBlock &MBB,
572 MachineBasicBlock::iterator &MBBI,
573 unsigned DestReg, unsigned BaseReg, int NumBytes,
574 ARMCC::CondCodes Pred, unsigned PredReg,
575 const TargetInstrInfo &TII) {
576 bool isSub = NumBytes < 0;
577 if (isSub) NumBytes = -NumBytes;
580 unsigned RotAmt = ARM_AM::getSOImmValRotate(NumBytes);
581 unsigned ThisVal = NumBytes & ARM_AM::rotr32(0xFF, RotAmt);
582 assert(ThisVal && "Didn't extract field correctly");
584 // We will handle these bits from offset, clear them.
585 NumBytes &= ~ThisVal;
587 // Get the properly encoded SOImmVal field.
588 int SOImmVal = ARM_AM::getSOImmVal(ThisVal);
589 assert(SOImmVal != -1 && "Bit extraction didn't work?");
591 // Build the new ADD / SUB.
592 BuildMI(MBB, MBBI, TII.get(isSub ? ARM::SUBri : ARM::ADDri), DestReg)
593 .addReg(BaseReg, false, false, true).addImm(SOImmVal)
594 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
599 /// calcNumMI - Returns the number of instructions required to materialize
600 /// the specific add / sub r, c instruction.
601 static unsigned calcNumMI(int Opc, int ExtraOpc, unsigned Bytes,
602 unsigned NumBits, unsigned Scale) {
604 unsigned Chunk = ((1 << NumBits) - 1) * Scale;
606 if (Opc == ARM::tADDrSPi) {
607 unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
611 Scale = 1; // Followed by a number of tADDi8.
612 Chunk = ((1 << NumBits) - 1) * Scale;
615 NumMIs += Bytes / Chunk;
616 if ((Bytes % Chunk) != 0)
623 /// emitThumbRegPlusImmInReg - Emits a series of instructions to materialize
624 /// a destreg = basereg + immediate in Thumb code. Materialize the immediate
625 /// in a register using mov / mvn sequences or load the immediate from a
628 void emitThumbRegPlusImmInReg(MachineBasicBlock &MBB,
629 MachineBasicBlock::iterator &MBBI,
630 unsigned DestReg, unsigned BaseReg,
631 int NumBytes, bool CanChangeCC,
632 const TargetInstrInfo &TII) {
633 bool isHigh = !isLowRegister(DestReg) ||
634 (BaseReg != 0 && !isLowRegister(BaseReg));
636 // Subtract doesn't have high register version. Load the negative value
637 // if either base or dest register is a high register. Also, if do not
638 // issue sub as part of the sequence if condition register is to be
640 if (NumBytes < 0 && !isHigh && CanChangeCC) {
642 NumBytes = -NumBytes;
644 unsigned LdReg = DestReg;
645 if (DestReg == ARM::SP) {
646 assert(BaseReg == ARM::SP && "Unexpected!");
648 BuildMI(MBB, MBBI, TII.get(ARM::tMOVr), ARM::R12)
649 .addReg(ARM::R3, false, false, true);
652 if (NumBytes <= 255 && NumBytes >= 0)
653 BuildMI(MBB, MBBI, TII.get(ARM::tMOVi8), LdReg).addImm(NumBytes);
654 else if (NumBytes < 0 && NumBytes >= -255) {
655 BuildMI(MBB, MBBI, TII.get(ARM::tMOVi8), LdReg).addImm(NumBytes);
656 BuildMI(MBB, MBBI, TII.get(ARM::tNEG), LdReg)
657 .addReg(LdReg, false, false, true);
659 emitLoadConstPool(MBB, MBBI, LdReg, NumBytes, ARMCC::AL, 0, TII, true);
662 int Opc = (isSub) ? ARM::tSUBrr : (isHigh ? ARM::tADDhirr : ARM::tADDrr);
663 const MachineInstrBuilder MIB = BuildMI(MBB, MBBI, TII.get(Opc), DestReg);
664 if (DestReg == ARM::SP || isSub)
665 MIB.addReg(BaseReg).addReg(LdReg, false, false, true);
667 MIB.addReg(LdReg).addReg(BaseReg, false, false, true);
668 if (DestReg == ARM::SP)
669 BuildMI(MBB, MBBI, TII.get(ARM::tMOVr), ARM::R3)
670 .addReg(ARM::R12, false, false, true);
673 /// emitThumbRegPlusImmediate - Emits a series of instructions to materialize
674 /// a destreg = basereg + immediate in Thumb code.
676 void emitThumbRegPlusImmediate(MachineBasicBlock &MBB,
677 MachineBasicBlock::iterator &MBBI,
678 unsigned DestReg, unsigned BaseReg,
679 int NumBytes, const TargetInstrInfo &TII) {
680 bool isSub = NumBytes < 0;
681 unsigned Bytes = (unsigned)NumBytes;
682 if (isSub) Bytes = -NumBytes;
683 bool isMul4 = (Bytes & 3) == 0;
684 bool isTwoAddr = false;
685 bool DstNotEqBase = false;
686 unsigned NumBits = 1;
691 if (DestReg == BaseReg && BaseReg == ARM::SP) {
692 assert(isMul4 && "Thumb sp inc / dec size must be multiple of 4!");
695 Opc = isSub ? ARM::tSUBspi : ARM::tADDspi;
697 } else if (!isSub && BaseReg == ARM::SP) {
700 // r1 = add sp, 100 * 4
704 ExtraOpc = ARM::tADDi3;
713 if (DestReg != BaseReg)
716 Opc = isSub ? ARM::tSUBi8 : ARM::tADDi8;
720 unsigned NumMIs = calcNumMI(Opc, ExtraOpc, Bytes, NumBits, Scale);
721 unsigned Threshold = (DestReg == ARM::SP) ? 3 : 2;
722 if (NumMIs > Threshold) {
723 // This will expand into too many instructions. Load the immediate from a
725 emitThumbRegPlusImmInReg(MBB, MBBI, DestReg, BaseReg, NumBytes, true, TII);
730 if (isLowRegister(DestReg) && isLowRegister(BaseReg)) {
731 // If both are low registers, emit DestReg = add BaseReg, max(Imm, 7)
732 unsigned Chunk = (1 << 3) - 1;
733 unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
735 BuildMI(MBB, MBBI, TII.get(isSub ? ARM::tSUBi3 : ARM::tADDi3), DestReg)
736 .addReg(BaseReg, false, false, true).addImm(ThisVal);
738 BuildMI(MBB, MBBI, TII.get(ARM::tMOVr), DestReg)
739 .addReg(BaseReg, false, false, true);
744 unsigned Chunk = ((1 << NumBits) - 1) * Scale;
746 unsigned ThisVal = (Bytes > Chunk) ? Chunk : Bytes;
749 // Build the new tADD / tSUB.
751 BuildMI(MBB, MBBI, TII.get(Opc), DestReg).addReg(DestReg).addImm(ThisVal);
753 bool isKill = BaseReg != ARM::SP;
754 BuildMI(MBB, MBBI, TII.get(Opc), DestReg)
755 .addReg(BaseReg, false, false, isKill).addImm(ThisVal);
758 if (Opc == ARM::tADDrSPi) {
764 Chunk = ((1 << NumBits) - 1) * Scale;
765 Opc = isSub ? ARM::tSUBi8 : ARM::tADDi8;
772 BuildMI(MBB, MBBI, TII.get(ExtraOpc), DestReg)
773 .addReg(DestReg, false, false, true)
774 .addImm(((unsigned)NumBytes) & 3);
778 void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
779 int NumBytes, ARMCC::CondCodes Pred, unsigned PredReg,
780 bool isThumb, const TargetInstrInfo &TII) {
782 emitThumbRegPlusImmediate(MBB, MBBI, ARM::SP, ARM::SP, NumBytes, TII);
784 emitARMRegPlusImmediate(MBB, MBBI, ARM::SP, ARM::SP, NumBytes,
788 void ARMRegisterInfo::
789 eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
790 MachineBasicBlock::iterator I) const {
791 if (!hasReservedCallFrame(MF)) {
792 // If we have alloca, convert as follows:
793 // ADJCALLSTACKDOWN -> sub, sp, sp, amount
794 // ADJCALLSTACKUP -> add, sp, sp, amount
795 MachineInstr *Old = I;
796 unsigned Amount = Old->getOperand(0).getImmedValue();
798 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
799 // We need to keep the stack aligned properly. To do this, we round the
800 // amount of space needed for the outgoing arguments up to the next
801 // alignment boundary.
802 unsigned Align = MF.getTarget().getFrameInfo()->getStackAlignment();
803 Amount = (Amount+Align-1)/Align*Align;
805 // Replace the pseudo instruction with a new instruction...
806 unsigned Opc = Old->getOpcode();
807 bool isThumb = AFI->isThumbFunction();
808 ARMCC::CondCodes Pred = isThumb
809 ? ARMCC::AL : (ARMCC::CondCodes)Old->getOperand(1).getImmedValue();
810 if (Opc == ARM::ADJCALLSTACKDOWN || Opc == ARM::tADJCALLSTACKDOWN) {
811 // Note: PredReg is operand 2 for ADJCALLSTACKDOWN.
812 unsigned PredReg = isThumb ? 0 : Old->getOperand(2).getReg();
813 emitSPUpdate(MBB, I, -Amount, Pred, PredReg, isThumb, TII);
815 // Note: PredReg is operand 3 for ADJCALLSTACKUP.
816 unsigned PredReg = isThumb ? 0 : Old->getOperand(3).getReg();
817 assert(Opc == ARM::ADJCALLSTACKUP || Opc == ARM::tADJCALLSTACKUP);
818 emitSPUpdate(MBB, I, Amount, Pred, PredReg, isThumb, TII);
825 /// emitThumbConstant - Emit a series of instructions to materialize a
827 static void emitThumbConstant(MachineBasicBlock &MBB,
828 MachineBasicBlock::iterator &MBBI,
829 unsigned DestReg, int Imm,
830 const TargetInstrInfo &TII) {
831 bool isSub = Imm < 0;
832 if (isSub) Imm = -Imm;
834 int Chunk = (1 << 8) - 1;
835 int ThisVal = (Imm > Chunk) ? Chunk : Imm;
837 BuildMI(MBB, MBBI, TII.get(ARM::tMOVi8), DestReg).addImm(ThisVal);
839 emitThumbRegPlusImmediate(MBB, MBBI, DestReg, DestReg, Imm, TII);
841 BuildMI(MBB, MBBI, TII.get(ARM::tNEG), DestReg)
842 .addReg(DestReg, false, false, true);
845 /// findScratchRegister - Find a 'free' ARM register. If register scavenger
846 /// is not being used, R12 is available. Otherwise, try for a call-clobbered
847 /// register first and then a spilled callee-saved register if that fails.
849 unsigned findScratchRegister(RegScavenger *RS, const TargetRegisterClass *RC,
850 ARMFunctionInfo *AFI) {
851 unsigned Reg = RS ? RS->FindUnusedReg(RC, true) : (unsigned) ARM::R12;
853 // Try a already spilled CS register.
854 Reg = RS->FindUnusedReg(RC, AFI->getSpilledCSRegisters());
859 void ARMRegisterInfo::eliminateFrameIndex(MachineBasicBlock::iterator II,
860 int SPAdj, RegScavenger *RS) const{
862 MachineInstr &MI = *II;
863 MachineBasicBlock &MBB = *MI.getParent();
864 MachineFunction &MF = *MBB.getParent();
865 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
866 bool isThumb = AFI->isThumbFunction();
868 while (!MI.getOperand(i).isFrameIndex()) {
870 assert(i < MI.getNumOperands() && "Instr doesn't have FrameIndex operand!");
873 unsigned FrameReg = ARM::SP;
874 int FrameIndex = MI.getOperand(i).getFrameIndex();
875 int Offset = MF.getFrameInfo()->getObjectOffset(FrameIndex) +
876 MF.getFrameInfo()->getStackSize() + SPAdj;
878 if (AFI->isGPRCalleeSavedArea1Frame(FrameIndex))
879 Offset -= AFI->getGPRCalleeSavedArea1Offset();
880 else if (AFI->isGPRCalleeSavedArea2Frame(FrameIndex))
881 Offset -= AFI->getGPRCalleeSavedArea2Offset();
882 else if (AFI->isDPRCalleeSavedAreaFrame(FrameIndex))
883 Offset -= AFI->getDPRCalleeSavedAreaOffset();
884 else if (hasFP(MF)) {
885 assert(SPAdj == 0 && "Unexpected");
886 // There is alloca()'s in this function, must reference off the frame
888 FrameReg = getFrameRegister(MF);
889 Offset -= AFI->getFramePtrSpillOffset();
892 unsigned Opcode = MI.getOpcode();
893 const TargetInstrDescriptor &Desc = TII.get(Opcode);
894 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
897 if (Opcode == ARM::ADDri) {
898 Offset += MI.getOperand(i+1).getImm();
900 // Turn it into a move.
901 MI.setInstrDescriptor(TII.get(ARM::MOVr));
902 MI.getOperand(i).ChangeToRegister(FrameReg, false);
903 MI.RemoveOperand(i+1);
905 } else if (Offset < 0) {
908 MI.setInstrDescriptor(TII.get(ARM::SUBri));
911 // Common case: small offset, fits into instruction.
912 int ImmedOffset = ARM_AM::getSOImmVal(Offset);
913 if (ImmedOffset != -1) {
914 // Replace the FrameIndex with sp / fp
915 MI.getOperand(i).ChangeToRegister(FrameReg, false);
916 MI.getOperand(i+1).ChangeToImmediate(ImmedOffset);
920 // Otherwise, we fallback to common code below to form the imm offset with
921 // a sequence of ADDri instructions. First though, pull as much of the imm
922 // into this ADDri as possible.
923 unsigned RotAmt = ARM_AM::getSOImmValRotate(Offset);
924 unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xFF, RotAmt);
926 // We will handle these bits from offset, clear them.
927 Offset &= ~ThisImmVal;
929 // Get the properly encoded SOImmVal field.
930 int ThisSOImmVal = ARM_AM::getSOImmVal(ThisImmVal);
931 assert(ThisSOImmVal != -1 && "Bit extraction didn't work?");
932 MI.getOperand(i+1).ChangeToImmediate(ThisSOImmVal);
933 } else if (Opcode == ARM::tADDrSPi) {
934 Offset += MI.getOperand(i+1).getImm();
936 // Can't use tADDrSPi if it's based off the frame pointer.
937 unsigned NumBits = 0;
939 if (FrameReg != ARM::SP) {
940 Opcode = ARM::tADDi3;
941 MI.setInstrDescriptor(TII.get(ARM::tADDi3));
946 assert((Offset & 3) == 0 &&
947 "Thumb add/sub sp, #imm immediate must be multiple of 4!");
951 // Turn it into a move.
952 MI.setInstrDescriptor(TII.get(ARM::tMOVr));
953 MI.getOperand(i).ChangeToRegister(FrameReg, false);
954 MI.RemoveOperand(i+1);
958 // Common case: small offset, fits into instruction.
959 unsigned Mask = (1 << NumBits) - 1;
960 if (((Offset / Scale) & ~Mask) == 0) {
961 // Replace the FrameIndex with sp / fp
962 MI.getOperand(i).ChangeToRegister(FrameReg, false);
963 MI.getOperand(i+1).ChangeToImmediate(Offset / Scale);
967 unsigned DestReg = MI.getOperand(0).getReg();
968 unsigned Bytes = (Offset > 0) ? Offset : -Offset;
969 unsigned NumMIs = calcNumMI(Opcode, 0, Bytes, NumBits, Scale);
970 // MI would expand into a large number of instructions. Don't try to
971 // simplify the immediate.
973 emitThumbRegPlusImmediate(MBB, II, DestReg, FrameReg, Offset, TII);
979 // Translate r0 = add sp, imm to
980 // r0 = add sp, 255*4
981 // r0 = add r0, (imm - 255*4)
982 MI.getOperand(i).ChangeToRegister(FrameReg, false);
983 MI.getOperand(i+1).ChangeToImmediate(Mask);
984 Offset = (Offset - Mask * Scale);
985 MachineBasicBlock::iterator NII = next(II);
986 emitThumbRegPlusImmediate(MBB, NII, DestReg, DestReg, Offset, TII);
988 // Translate r0 = add sp, -imm to
989 // r0 = -imm (this is then translated into a series of instructons)
991 emitThumbConstant(MBB, II, DestReg, Offset, TII);
992 MI.setInstrDescriptor(TII.get(ARM::tADDhirr));
993 MI.getOperand(i).ChangeToRegister(DestReg, false, false, true);
994 MI.getOperand(i+1).ChangeToRegister(FrameReg, false);
1000 unsigned NumBits = 0;
1003 case ARMII::AddrMode2: {
1005 InstrOffs = ARM_AM::getAM2Offset(MI.getOperand(ImmIdx).getImm());
1006 if (ARM_AM::getAM2Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
1011 case ARMII::AddrMode3: {
1013 InstrOffs = ARM_AM::getAM3Offset(MI.getOperand(ImmIdx).getImm());
1014 if (ARM_AM::getAM3Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
1019 case ARMII::AddrMode5: {
1021 InstrOffs = ARM_AM::getAM5Offset(MI.getOperand(ImmIdx).getImm());
1022 if (ARM_AM::getAM5Op(MI.getOperand(ImmIdx).getImm()) == ARM_AM::sub)
1028 case ARMII::AddrModeTs: {
1030 InstrOffs = MI.getOperand(ImmIdx).getImm();
1031 NumBits = (FrameReg == ARM::SP) ? 8 : 5;
1036 assert(0 && "Unsupported addressing mode!");
1041 Offset += InstrOffs * Scale;
1042 assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
1043 if (Offset < 0 && !isThumb) {
1048 // Common case: small offset, fits into instruction.
1049 MachineOperand &ImmOp = MI.getOperand(ImmIdx);
1050 int ImmedOffset = Offset / Scale;
1051 unsigned Mask = (1 << NumBits) - 1;
1052 if ((unsigned)Offset <= Mask * Scale) {
1053 // Replace the FrameIndex with sp
1054 MI.getOperand(i).ChangeToRegister(FrameReg, false);
1056 ImmedOffset |= 1 << NumBits;
1057 ImmOp.ChangeToImmediate(ImmedOffset);
1061 bool isThumSpillRestore = Opcode == ARM::tRestore || Opcode == ARM::tSpill;
1062 if (AddrMode == ARMII::AddrModeTs) {
1063 // Thumb tLDRspi, tSTRspi. These will change to instructions that use
1064 // a different base register.
1066 Mask = (1 << NumBits) - 1;
1068 // If this is a thumb spill / restore, we will be using a constpool load to
1069 // materialize the offset.
1070 if (AddrMode == ARMII::AddrModeTs && isThumSpillRestore)
1071 ImmOp.ChangeToImmediate(0);
1073 // Otherwise, it didn't fit. Pull in what we can to simplify the immed.
1074 ImmedOffset = ImmedOffset & Mask;
1076 ImmedOffset |= 1 << NumBits;
1077 ImmOp.ChangeToImmediate(ImmedOffset);
1078 Offset &= ~(Mask*Scale);
1082 // If we get here, the immediate doesn't fit into the instruction. We folded
1083 // as much as possible above, handle the rest, providing a register that is
1085 assert(Offset && "This code isn't needed if offset already handled!");
1088 if (TII.isLoad(Opcode)) {
1089 // Use the destination register to materialize sp + offset.
1090 unsigned TmpReg = MI.getOperand(0).getReg();
1092 if (Opcode == ARM::tRestore) {
1093 if (FrameReg == ARM::SP)
1094 emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg,Offset,false,TII);
1096 emitLoadConstPool(MBB, II, TmpReg, Offset, ARMCC::AL, 0, TII, true);
1100 emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII);
1101 MI.setInstrDescriptor(TII.get(ARM::tLDR));
1102 MI.getOperand(i).ChangeToRegister(TmpReg, false, false, true);
1104 MI.addRegOperand(FrameReg, false); // Use [reg, reg] addrmode.
1106 MI.addRegOperand(0, false); // tLDR has an extra register operand.
1107 } else if (TII.isStore(Opcode)) {
1108 // FIXME! This is horrific!!! We need register scavenging.
1109 // Our temporary workaround has marked r3 unavailable. Of course, r3 is
1110 // also a ABI register so it's possible that is is the register that is
1111 // being storing here. If that's the case, we do the following:
1113 // Use r2 to materialize sp + offset
1116 unsigned ValReg = MI.getOperand(0).getReg();
1117 unsigned TmpReg = ARM::R3;
1119 if (ValReg == ARM::R3) {
1120 BuildMI(MBB, II, TII.get(ARM::tMOVr), ARM::R12)
1121 .addReg(ARM::R2, false, false, true);
1124 if (TmpReg == ARM::R3 && AFI->isR3LiveIn())
1125 BuildMI(MBB, II, TII.get(ARM::tMOVr), ARM::R12)
1126 .addReg(ARM::R3, false, false, true);
1127 if (Opcode == ARM::tSpill) {
1128 if (FrameReg == ARM::SP)
1129 emitThumbRegPlusImmInReg(MBB, II, TmpReg, FrameReg,Offset,false,TII);
1131 emitLoadConstPool(MBB, II, TmpReg, Offset, ARMCC::AL, 0, TII, true);
1135 emitThumbRegPlusImmediate(MBB, II, TmpReg, FrameReg, Offset, TII);
1136 MI.setInstrDescriptor(TII.get(ARM::tSTR));
1137 MI.getOperand(i).ChangeToRegister(TmpReg, false, false, true);
1139 MI.addRegOperand(FrameReg, false); // Use [reg, reg] addrmode.
1141 MI.addRegOperand(0, false); // tSTR has an extra register operand.
1143 MachineBasicBlock::iterator NII = next(II);
1144 if (ValReg == ARM::R3)
1145 BuildMI(MBB, NII, TII.get(ARM::tMOVr), ARM::R2)
1146 .addReg(ARM::R12, false, false, true);
1147 if (TmpReg == ARM::R3 && AFI->isR3LiveIn())
1148 BuildMI(MBB, NII, TII.get(ARM::tMOVr), ARM::R3)
1149 .addReg(ARM::R12, false, false, true);
1151 assert(false && "Unexpected opcode!");
1153 // Insert a set of r12 with the full address: r12 = sp + offset
1154 // If the offset we have is too large to fit into the instruction, we need
1155 // to form it with a series of ADDri's. Do this by taking 8-bit chunks
1157 unsigned ScratchReg = findScratchRegister(RS, &ARM::GPRRegClass, AFI);
1158 if (ScratchReg == 0)
1159 // No register is "free". Scavenge a register.
1160 ScratchReg = RS->scavengeRegister(&ARM::GPRRegClass, II, SPAdj);
1161 int PIdx = MI.findFirstPredOperandIdx();
1162 ARMCC::CondCodes Pred = (PIdx == -1)
1163 ? ARMCC::AL : (ARMCC::CondCodes)MI.getOperand(PIdx).getImmedValue();
1164 unsigned PredReg = (PIdx == -1) ? 0 : MI.getOperand(PIdx+1).getReg();
1165 emitARMRegPlusImmediate(MBB, II, ScratchReg, FrameReg,
1166 isSub ? -Offset : Offset, Pred, PredReg, TII);
1167 MI.getOperand(i).ChangeToRegister(ScratchReg, false, false, true);
1171 static unsigned estimateStackSize(MachineFunction &MF, MachineFrameInfo *MFI) {
1172 const MachineFrameInfo *FFI = MF.getFrameInfo();
1174 for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) {
1175 int FixedOff = -FFI->getObjectOffset(i);
1176 if (FixedOff > Offset) Offset = FixedOff;
1178 for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
1179 Offset += FFI->getObjectSize(i);
1180 unsigned Align = FFI->getObjectAlignment(i);
1181 // Adjust to alignment boundary
1182 Offset = (Offset+Align-1)/Align*Align;
1184 return (unsigned)Offset;
1188 ARMRegisterInfo::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
1189 RegScavenger *RS) const {
1190 // This tells PEI to spill the FP as if it is any other callee-save register
1191 // to take advantage the eliminateFrameIndex machinery. This also ensures it
1192 // is spilled in the order specified by getCalleeSavedRegs() to make it easier
1193 // to combine multiple loads / stores.
1194 bool CanEliminateFrame = true;
1195 bool CS1Spilled = false;
1196 bool LRSpilled = false;
1197 unsigned NumGPRSpills = 0;
1198 SmallVector<unsigned, 4> UnspilledCS1GPRs;
1199 SmallVector<unsigned, 4> UnspilledCS2GPRs;
1200 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1202 // Don't spill FP if the frame can be eliminated. This is determined
1203 // by scanning the callee-save registers to see if any is used.
1204 const unsigned *CSRegs = getCalleeSavedRegs();
1205 const TargetRegisterClass* const *CSRegClasses = getCalleeSavedRegClasses();
1206 for (unsigned i = 0; CSRegs[i]; ++i) {
1207 unsigned Reg = CSRegs[i];
1208 bool Spilled = false;
1209 if (MF.isPhysRegUsed(Reg)) {
1210 AFI->setCSRegisterIsSpilled(Reg);
1212 CanEliminateFrame = false;
1214 // Check alias registers too.
1215 for (const unsigned *Aliases = getAliasSet(Reg); *Aliases; ++Aliases) {
1216 if (MF.isPhysRegUsed(*Aliases)) {
1218 CanEliminateFrame = false;
1223 if (CSRegClasses[i] == &ARM::GPRRegClass) {
1227 if (!STI.isTargetDarwin()) {
1234 // Keep track if LR and any of R4, R5, R6, and R7 is spilled.
1249 if (!STI.isTargetDarwin()) {
1250 UnspilledCS1GPRs.push_back(Reg);
1260 UnspilledCS1GPRs.push_back(Reg);
1263 UnspilledCS2GPRs.push_back(Reg);
1270 bool ForceLRSpill = false;
1271 if (!LRSpilled && AFI->isThumbFunction()) {
1272 unsigned FnSize = ARM::GetFunctionSize(MF);
1273 // Force LR to be spilled if the Thumb function size is > 2048. This enables
1274 // use of BL to implement far jump. If it turns out that it's not needed
1275 // then the branch fix up path will undo it.
1276 if (FnSize >= (1 << 11)) {
1277 CanEliminateFrame = false;
1278 ForceLRSpill = true;
1282 bool ExtraCSSpill = false;
1283 if (!CanEliminateFrame || hasFP(MF)) {
1284 AFI->setHasStackFrame(true);
1286 // If LR is not spilled, but at least one of R4, R5, R6, and R7 is spilled.
1287 // Spill LR as well so we can fold BX_RET to the registers restore (LDM).
1288 if (!LRSpilled && CS1Spilled) {
1289 MF.setPhysRegUsed(ARM::LR);
1290 AFI->setCSRegisterIsSpilled(ARM::LR);
1292 UnspilledCS1GPRs.erase(std::find(UnspilledCS1GPRs.begin(),
1293 UnspilledCS1GPRs.end(), (unsigned)ARM::LR));
1294 ForceLRSpill = false;
1295 ExtraCSSpill = true;
1298 // Darwin ABI requires FP to point to the stack slot that contains the
1300 if (STI.isTargetDarwin() || hasFP(MF)) {
1301 MF.setPhysRegUsed(FramePtr);
1305 // If stack and double are 8-byte aligned and we are spilling an odd number
1306 // of GPRs. Spill one extra callee save GPR so we won't have to pad between
1307 // the integer and double callee save areas.
1308 unsigned TargetAlign = MF.getTarget().getFrameInfo()->getStackAlignment();
1309 if (TargetAlign == 8 && (NumGPRSpills & 1)) {
1310 if (CS1Spilled && !UnspilledCS1GPRs.empty()) {
1311 for (unsigned i = 0, e = UnspilledCS1GPRs.size(); i != e; ++i) {
1312 unsigned Reg = UnspilledCS1GPRs[i];
1313 // Don't spiil high register if the function is thumb
1314 if (!AFI->isThumbFunction() || isLowRegister(Reg) || Reg == ARM::LR) {
1315 MF.setPhysRegUsed(Reg);
1316 AFI->setCSRegisterIsSpilled(Reg);
1317 if (!isReservedReg(MF, Reg))
1318 ExtraCSSpill = true;
1322 } else if (!UnspilledCS2GPRs.empty() &&
1323 !AFI->isThumbFunction()) {
1324 unsigned Reg = UnspilledCS2GPRs.front();
1325 MF.setPhysRegUsed(Reg);
1326 AFI->setCSRegisterIsSpilled(Reg);
1327 if (!isReservedReg(MF, Reg))
1328 ExtraCSSpill = true;
1332 // Estimate if we might need to scavenge a register at some point in order
1333 // to materialize a stack offset. If so, either spill one additiona
1334 // callee-saved register or reserve a special spill slot to facilitate
1335 // register scavenging.
1336 if (RS && !ExtraCSSpill && !AFI->isThumbFunction()) {
1337 MachineFrameInfo *MFI = MF.getFrameInfo();
1338 unsigned Size = estimateStackSize(MF, MFI);
1339 unsigned Limit = (1 << 12) - 1;
1340 for (MachineFunction::iterator BB = MF.begin(),E = MF.end();BB != E; ++BB)
1341 for (MachineBasicBlock::iterator I= BB->begin(); I != BB->end(); ++I) {
1342 for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
1343 if (I->getOperand(i).isFrameIndex()) {
1344 unsigned Opcode = I->getOpcode();
1345 const TargetInstrDescriptor &Desc = TII.get(Opcode);
1346 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
1347 if (AddrMode == ARMII::AddrMode3) {
1348 Limit = (1 << 8) - 1;
1349 goto DoneEstimating;
1350 } else if (AddrMode == ARMII::AddrMode5) {
1351 unsigned ThisLimit = ((1 << 8) - 1) * 4;
1352 if (ThisLimit < Limit)
1358 if (Size >= Limit) {
1359 // If any non-reserved CS register isn't spilled, just spill one or two
1360 // extra. That should take care of it!
1361 unsigned NumExtras = TargetAlign / 4;
1362 SmallVector<unsigned, 2> Extras;
1363 while (NumExtras && !UnspilledCS1GPRs.empty()) {
1364 unsigned Reg = UnspilledCS1GPRs.back();
1365 UnspilledCS1GPRs.pop_back();
1366 if (!isReservedReg(MF, Reg)) {
1367 Extras.push_back(Reg);
1371 while (NumExtras && !UnspilledCS2GPRs.empty()) {
1372 unsigned Reg = UnspilledCS2GPRs.back();
1373 UnspilledCS2GPRs.pop_back();
1374 if (!isReservedReg(MF, Reg)) {
1375 Extras.push_back(Reg);
1379 if (Extras.size() && NumExtras == 0) {
1380 for (unsigned i = 0, e = Extras.size(); i != e; ++i) {
1381 MF.setPhysRegUsed(Extras[i]);
1382 AFI->setCSRegisterIsSpilled(Extras[i]);
1385 // Reserve a slot closest to SP or frame pointer.
1386 const TargetRegisterClass *RC = &ARM::GPRRegClass;
1387 RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
1388 RC->getAlignment()));
1395 MF.setPhysRegUsed(ARM::LR);
1396 AFI->setCSRegisterIsSpilled(ARM::LR);
1397 AFI->setLRIsSpilledForFarJump(true);
1401 /// Move iterator pass the next bunch of callee save load / store ops for
1402 /// the particular spill area (1: integer area 1, 2: integer area 2,
1403 /// 3: fp area, 0: don't care).
1404 static void movePastCSLoadStoreOps(MachineBasicBlock &MBB,
1405 MachineBasicBlock::iterator &MBBI,
1406 int Opc, unsigned Area,
1407 const ARMSubtarget &STI) {
1408 while (MBBI != MBB.end() &&
1409 MBBI->getOpcode() == Opc && MBBI->getOperand(1).isFrameIndex()) {
1412 unsigned Category = 0;
1413 switch (MBBI->getOperand(0).getReg()) {
1414 case ARM::R4: case ARM::R5: case ARM::R6: case ARM::R7:
1418 case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11:
1419 Category = STI.isTargetDarwin() ? 2 : 1;
1421 case ARM::D8: case ARM::D9: case ARM::D10: case ARM::D11:
1422 case ARM::D12: case ARM::D13: case ARM::D14: case ARM::D15:
1429 if (Done || Category != Area)
1437 void ARMRegisterInfo::emitPrologue(MachineFunction &MF) const {
1438 MachineBasicBlock &MBB = MF.front();
1439 MachineBasicBlock::iterator MBBI = MBB.begin();
1440 MachineFrameInfo *MFI = MF.getFrameInfo();
1441 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1442 bool isThumb = AFI->isThumbFunction();
1443 unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
1444 unsigned NumBytes = MFI->getStackSize();
1445 const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
1448 // Check if R3 is live in. It might have to be used as a scratch register.
1449 for (MachineFunction::livein_iterator I=MF.livein_begin(),E=MF.livein_end();
1451 if ((*I).first == ARM::R3) {
1452 AFI->setR3IsLiveIn(true);
1457 // Thumb add/sub sp, imm8 instructions implicitly multiply the offset by 4.
1458 NumBytes = (NumBytes + 3) & ~3;
1459 MFI->setStackSize(NumBytes);
1462 // Determine the sizes of each callee-save spill areas and record which frame
1463 // belongs to which callee-save spill areas.
1464 unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
1465 int FramePtrSpillFI = 0;
1468 emitSPUpdate(MBB, MBBI, -VARegSaveSize, ARMCC::AL, 0, isThumb, TII);
1470 if (!AFI->hasStackFrame()) {
1472 emitSPUpdate(MBB, MBBI, -NumBytes, ARMCC::AL, 0, isThumb, TII);
1476 for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
1477 unsigned Reg = CSI[i].getReg();
1478 int FI = CSI[i].getFrameIdx();
1485 if (Reg == FramePtr)
1486 FramePtrSpillFI = FI;
1487 AFI->addGPRCalleeSavedArea1Frame(FI);
1494 if (Reg == FramePtr)
1495 FramePtrSpillFI = FI;
1496 if (STI.isTargetDarwin()) {
1497 AFI->addGPRCalleeSavedArea2Frame(FI);
1500 AFI->addGPRCalleeSavedArea1Frame(FI);
1505 AFI->addDPRCalleeSavedAreaFrame(FI);
1511 // Build the new SUBri to adjust SP for integer callee-save spill area 1.
1512 emitSPUpdate(MBB, MBBI, -GPRCS1Size, ARMCC::AL, 0, isThumb, TII);
1513 movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, 1, STI);
1514 } else if (MBBI != MBB.end() && MBBI->getOpcode() == ARM::tPUSH)
1517 // Darwin ABI requires FP to point to the stack slot that contains the
1519 if (STI.isTargetDarwin() || hasFP(MF)) {
1520 MachineInstrBuilder MIB =
1521 BuildMI(MBB, MBBI, TII.get(isThumb ? ARM::tADDrSPi : ARM::ADDri),FramePtr)
1522 .addFrameIndex(FramePtrSpillFI).addImm(0);
1523 if (!isThumb) AddDefaultCC(AddDefaultPred(MIB));
1527 // Build the new SUBri to adjust SP for integer callee-save spill area 2.
1528 emitSPUpdate(MBB, MBBI, -GPRCS2Size, ARMCC::AL, 0, false, TII);
1530 // Build the new SUBri to adjust SP for FP callee-save spill area.
1531 movePastCSLoadStoreOps(MBB, MBBI, ARM::STR, 2, STI);
1532 emitSPUpdate(MBB, MBBI, -DPRCSSize, ARMCC::AL, 0, false, TII);
1535 // Determine starting offsets of spill areas.
1536 unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
1537 unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
1538 unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
1539 AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) + NumBytes);
1540 AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
1541 AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
1542 AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
1544 NumBytes = DPRCSOffset;
1546 // Insert it after all the callee-save spills.
1548 movePastCSLoadStoreOps(MBB, MBBI, ARM::FSTD, 3, STI);
1549 emitSPUpdate(MBB, MBBI, -NumBytes, ARMCC::AL, 0, isThumb, TII);
1552 if(STI.isTargetELF() && hasFP(MF)) {
1553 MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
1554 AFI->getFramePtrSpillOffset());
1557 AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
1558 AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
1559 AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
1562 static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
1563 for (unsigned i = 0; CSRegs[i]; ++i)
1564 if (Reg == CSRegs[i])
1569 static bool isCSRestore(MachineInstr *MI, const unsigned *CSRegs) {
1570 return ((MI->getOpcode() == ARM::FLDD ||
1571 MI->getOpcode() == ARM::LDR ||
1572 MI->getOpcode() == ARM::tRestore) &&
1573 MI->getOperand(1).isFrameIndex() &&
1574 isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs));
1577 void ARMRegisterInfo::emitEpilogue(MachineFunction &MF,
1578 MachineBasicBlock &MBB) const {
1579 MachineBasicBlock::iterator MBBI = prior(MBB.end());
1580 assert((MBBI->getOpcode() == ARM::BX_RET ||
1581 MBBI->getOpcode() == ARM::tBX_RET ||
1582 MBBI->getOpcode() == ARM::tPOP_RET) &&
1583 "Can only insert epilog into returning blocks");
1585 MachineFrameInfo *MFI = MF.getFrameInfo();
1586 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
1587 bool isThumb = AFI->isThumbFunction();
1588 unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
1589 int NumBytes = (int)MFI->getStackSize();
1590 if (!AFI->hasStackFrame()) {
1592 emitSPUpdate(MBB, MBBI, NumBytes, ARMCC::AL, 0, isThumb, TII);
1594 // Unwind MBBI to point to first LDR / FLDD.
1595 const unsigned *CSRegs = getCalleeSavedRegs();
1596 if (MBBI != MBB.begin()) {
1599 while (MBBI != MBB.begin() && isCSRestore(MBBI, CSRegs));
1600 if (!isCSRestore(MBBI, CSRegs))
1604 // Move SP to start of FP callee save spill area.
1605 NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
1606 AFI->getGPRCalleeSavedArea2Size() +
1607 AFI->getDPRCalleeSavedAreaSize());
1610 NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
1611 // Reset SP based on frame pointer only if the stack frame extends beyond
1612 // frame pointer stack slot or target is ELF and the function has FP.
1614 emitThumbRegPlusImmediate(MBB, MBBI, ARM::SP, FramePtr, -NumBytes, TII);
1616 BuildMI(MBB, MBBI, TII.get(ARM::tMOVr), ARM::SP).addReg(FramePtr);
1618 if (MBBI->getOpcode() == ARM::tBX_RET &&
1619 &MBB.front() != MBBI &&
1620 prior(MBBI)->getOpcode() == ARM::tPOP) {
1621 MachineBasicBlock::iterator PMBBI = prior(MBBI);
1622 emitSPUpdate(MBB, PMBBI, NumBytes, ARMCC::AL, 0, isThumb, TII);
1624 emitSPUpdate(MBB, MBBI, NumBytes, ARMCC::AL, 0, isThumb, TII);
1627 // Darwin ABI requires FP to point to the stack slot that contains the
1629 if ((STI.isTargetDarwin() && NumBytes) || hasFP(MF)) {
1630 NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
1631 // Reset SP based on frame pointer only if the stack frame extends beyond
1632 // frame pointer stack slot or target is ELF and the function has FP.
1633 if (AFI->getGPRCalleeSavedArea2Size() ||
1634 AFI->getDPRCalleeSavedAreaSize() ||
1635 AFI->getDPRCalleeSavedAreaOffset()||
1638 BuildMI(MBB, MBBI, TII.get(ARM::SUBri), ARM::SP).addReg(FramePtr)
1640 .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
1642 BuildMI(MBB, MBBI, TII.get(ARM::MOVr), ARM::SP).addReg(FramePtr)
1643 .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
1644 } else if (NumBytes) {
1645 emitSPUpdate(MBB, MBBI, NumBytes, ARMCC::AL, 0, false, TII);
1648 // Move SP to start of integer callee save spill area 2.
1649 movePastCSLoadStoreOps(MBB, MBBI, ARM::FLDD, 3, STI);
1650 emitSPUpdate(MBB, MBBI, AFI->getDPRCalleeSavedAreaSize(), ARMCC::AL, 0,
1653 // Move SP to start of integer callee save spill area 1.
1654 movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, 2, STI);
1655 emitSPUpdate(MBB, MBBI, AFI->getGPRCalleeSavedArea2Size(), ARMCC::AL, 0,
1658 // Move SP to SP upon entry to the function.
1659 movePastCSLoadStoreOps(MBB, MBBI, ARM::LDR, 1, STI);
1660 emitSPUpdate(MBB, MBBI, AFI->getGPRCalleeSavedArea1Size(), ARMCC::AL, 0,
1665 if (VARegSaveSize) {
1667 // Epilogue for vararg functions: pop LR to R3 and branch off it.
1668 // FIXME: Verify this is still ok when R3 is no longer being reserved.
1669 BuildMI(MBB, MBBI, TII.get(ARM::tPOP)).addReg(ARM::R3);
1671 emitSPUpdate(MBB, MBBI, VARegSaveSize, ARMCC::AL, 0, isThumb, TII);
1674 BuildMI(MBB, MBBI, TII.get(ARM::tBX_RET_vararg)).addReg(ARM::R3);
1680 unsigned ARMRegisterInfo::getRARegister() const {
1684 unsigned ARMRegisterInfo::getFrameRegister(MachineFunction &MF) const {
1685 if (STI.isTargetDarwin() || hasFP(MF))
1686 return (STI.useThumbBacktraces() || STI.isThumb()) ? ARM::R7 : ARM::R11;
1691 unsigned ARMRegisterInfo::getEHExceptionRegister() const {
1692 assert(0 && "What is the exception register");
1696 unsigned ARMRegisterInfo::getEHHandlerRegister() const {
1697 assert(0 && "What is the exception handler register");
1701 int ARMRegisterInfo::getDwarfRegNum(unsigned RegNum, bool isEH) const {
1702 assert(0 && "What is the dwarf register number");
1706 #include "ARMGenRegisterInfo.inc"