1 //===- Thumb2InstrInfo.cpp - Thumb-2 Instruction Information --------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the Thumb-2 implementation of the TargetInstrInfo class.
12 //===----------------------------------------------------------------------===//
14 #include "Thumb2InstrInfo.h"
16 #include "ARMConstantPoolValue.h"
17 #include "ARMAddressingModes.h"
18 #include "ARMGenInstrInfo.inc"
19 #include "ARMMachineFunctionInfo.h"
20 #include "llvm/GlobalValue.h"
21 #include "llvm/CodeGen/MachineConstantPool.h"
22 #include "llvm/CodeGen/MachineFrameInfo.h"
23 #include "llvm/CodeGen/MachineInstrBuilder.h"
24 #include "llvm/CodeGen/MachineMemOperand.h"
25 #include "llvm/CodeGen/PseudoSourceValue.h"
26 #include "llvm/ADT/SmallVector.h"
27 #include "Thumb2InstrInfo.h"
31 Thumb2InstrInfo::Thumb2InstrInfo(const ARMSubtarget &STI)
32 : ARMBaseInstrInfo(STI), RI(*this, STI) {
35 unsigned Thumb2InstrInfo::getUnindexedOpcode(unsigned Opc) const {
41 Thumb2InstrInfo::BlockHasNoFallThrough(const MachineBasicBlock &MBB) const {
42 if (MBB.empty()) return false;
44 switch (MBB.back().getOpcode()) {
46 case ARM::t2B: // Uncond branch.
47 case ARM::t2BR_JT: // Jumptable branch.
48 case ARM::t2TBB: // Table branch byte.
49 case ARM::t2TBH: // Table branch halfword.
50 case ARM::tBR_JTr: // Jumptable branch (16-bit version).
52 case ARM::tBX_RET_vararg:
65 Thumb2InstrInfo::copyRegToReg(MachineBasicBlock &MBB,
66 MachineBasicBlock::iterator I,
67 unsigned DestReg, unsigned SrcReg,
68 const TargetRegisterClass *DestRC,
69 const TargetRegisterClass *SrcRC) const {
70 DebugLoc DL = DebugLoc::getUnknownLoc();
71 if (I != MBB.end()) DL = I->getDebugLoc();
73 if (DestRC == ARM::GPRRegisterClass &&
74 SrcRC == ARM::GPRRegisterClass) {
75 BuildMI(MBB, I, DL, get(ARM::tMOVgpr2gpr), DestReg).addReg(SrcReg);
77 } else if (DestRC == ARM::GPRRegisterClass &&
78 SrcRC == ARM::tGPRRegisterClass) {
79 BuildMI(MBB, I, DL, get(ARM::tMOVtgpr2gpr), DestReg).addReg(SrcReg);
81 } else if (DestRC == ARM::tGPRRegisterClass &&
82 SrcRC == ARM::GPRRegisterClass) {
83 BuildMI(MBB, I, DL, get(ARM::tMOVgpr2tgpr), DestReg).addReg(SrcReg);
87 // Handle SPR, DPR, and QPR copies.
88 return ARMBaseInstrInfo::copyRegToReg(MBB, I, DestReg, SrcReg, DestRC, SrcRC);
91 void Thumb2InstrInfo::
92 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
93 unsigned SrcReg, bool isKill, int FI,
94 const TargetRegisterClass *RC) const {
95 DebugLoc DL = DebugLoc::getUnknownLoc();
96 if (I != MBB.end()) DL = I->getDebugLoc();
98 if (RC == ARM::GPRRegisterClass) {
99 MachineFunction &MF = *MBB.getParent();
100 MachineFrameInfo &MFI = *MF.getFrameInfo();
101 MachineMemOperand *MMO =
102 MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FI),
103 MachineMemOperand::MOStore, 0,
104 MFI.getObjectSize(FI),
105 MFI.getObjectAlignment(FI));
106 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::t2STRi12))
107 .addReg(SrcReg, getKillRegState(isKill))
108 .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
112 ARMBaseInstrInfo::storeRegToStackSlot(MBB, I, SrcReg, isKill, FI, RC);
115 void Thumb2InstrInfo::
116 loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
117 unsigned DestReg, int FI,
118 const TargetRegisterClass *RC) const {
119 DebugLoc DL = DebugLoc::getUnknownLoc();
120 if (I != MBB.end()) DL = I->getDebugLoc();
122 if (RC == ARM::GPRRegisterClass) {
123 MachineFunction &MF = *MBB.getParent();
124 MachineFrameInfo &MFI = *MF.getFrameInfo();
125 MachineMemOperand *MMO =
126 MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FI),
127 MachineMemOperand::MOLoad, 0,
128 MFI.getObjectSize(FI),
129 MFI.getObjectAlignment(FI));
130 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::t2LDRi12), DestReg)
131 .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
135 ARMBaseInstrInfo::loadRegFromStackSlot(MBB, I, DestReg, FI, RC);
138 void Thumb2InstrInfo::reMaterialize(MachineBasicBlock &MBB,
139 MachineBasicBlock::iterator I,
140 unsigned DestReg, unsigned SubIdx,
141 const MachineInstr *Orig) const {
142 DebugLoc dl = Orig->getDebugLoc();
143 unsigned Opcode = Orig->getOpcode();
146 MachineInstr *MI = MBB.getParent()->CloneMachineInstr(Orig);
147 MI->getOperand(0).setReg(DestReg);
151 case ARM::t2LDRpci_pic: {
152 MachineFunction &MF = *MBB.getParent();
153 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
154 MachineConstantPool *MCP = MF.getConstantPool();
155 unsigned CPI = Orig->getOperand(1).getIndex();
156 const MachineConstantPoolEntry &MCPE = MCP->getConstants()[CPI];
157 assert(MCPE.isMachineConstantPoolEntry() &&
158 "Expecting a machine constantpool entry!");
159 ARMConstantPoolValue *ACPV =
160 static_cast<ARMConstantPoolValue*>(MCPE.Val.MachineCPVal);
161 assert(ACPV->isGlobalValue() && "Expecting a GV!");
162 unsigned PCLabelId = AFI->createConstPoolEntryUId();
163 ARMConstantPoolValue *NewCPV =
164 new ARMConstantPoolValue(ACPV->getGV(), PCLabelId, ARMCP::CPValue, 4);
165 CPI = MCP->getConstantPoolIndex(NewCPV, MCPE.getAlignment());
166 MachineInstrBuilder MIB = BuildMI(MBB, I, Orig->getDebugLoc(), get(Opcode),
168 .addConstantPoolIndex(CPI).addImm(PCLabelId);
169 (*MIB).setMemRefs(Orig->memoperands_begin(), Orig->memoperands_end());
174 MachineInstr *NewMI = prior(I);
175 NewMI->getOperand(0).setSubReg(SubIdx);
178 bool Thumb2InstrInfo::isIdentical(const MachineInstr *MI0,
179 const MachineInstr *MI1,
180 const MachineRegisterInfo *MRI) const {
181 unsigned Opcode = MI0->getOpcode();
182 if (Opcode == ARM::t2LDRpci_pic) {
183 const MachineOperand &MO0 = MI0->getOperand(1);
184 const MachineOperand &MO1 = MI1->getOperand(1);
185 if (MO0.getOffset() != MO1.getOffset())
188 const MachineFunction *MF = MI0->getParent()->getParent();
189 const MachineConstantPool *MCP = MF->getConstantPool();
190 int CPI0 = MO0.getIndex();
191 int CPI1 = MO1.getIndex();
192 const MachineConstantPoolEntry &MCPE0 = MCP->getConstants()[CPI0];
193 const MachineConstantPoolEntry &MCPE1 = MCP->getConstants()[CPI1];
194 ARMConstantPoolValue *ACPV0 =
195 static_cast<ARMConstantPoolValue*>(MCPE0.Val.MachineCPVal);
196 ARMConstantPoolValue *ACPV1 =
197 static_cast<ARMConstantPoolValue*>(MCPE1.Val.MachineCPVal);
198 return ACPV0->hasSameValue(ACPV1);
201 return TargetInstrInfoImpl::isIdentical(MI0, MI1, MRI);
204 void llvm::emitT2RegPlusImmediate(MachineBasicBlock &MBB,
205 MachineBasicBlock::iterator &MBBI, DebugLoc dl,
206 unsigned DestReg, unsigned BaseReg, int NumBytes,
207 ARMCC::CondCodes Pred, unsigned PredReg,
208 const ARMBaseInstrInfo &TII) {
209 bool isSub = NumBytes < 0;
210 if (isSub) NumBytes = -NumBytes;
212 // If profitable, use a movw or movt to materialize the offset.
213 // FIXME: Use the scavenger to grab a scratch register.
214 if (DestReg != ARM::SP && DestReg != BaseReg &&
216 ARM_AM::getT2SOImmVal(NumBytes) == -1) {
218 if (NumBytes < 65536) {
219 // Use a movw to materialize the 16-bit constant.
220 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2MOVi16), DestReg)
222 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
224 } else if ((NumBytes & 0xffff) == 0) {
225 // Use a movt to materialize the 32-bit constant.
226 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2MOVTi16), DestReg)
228 .addImm(NumBytes >> 16)
229 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
235 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2SUBrr), DestReg)
236 .addReg(BaseReg, RegState::Kill)
237 .addReg(DestReg, RegState::Kill)
238 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
240 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2ADDrr), DestReg)
241 .addReg(DestReg, RegState::Kill)
242 .addReg(BaseReg, RegState::Kill)
243 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
250 unsigned ThisVal = NumBytes;
252 if (DestReg == ARM::SP && BaseReg != ARM::SP) {
253 // mov sp, rn. Note t2MOVr cannot be used.
254 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2gpr),DestReg).addReg(BaseReg);
259 if (BaseReg == ARM::SP) {
261 if (DestReg == ARM::SP && (ThisVal < ((1 << 7)-1) * 4)) {
262 assert((ThisVal & 3) == 0 && "Stack update is not multiple of 4?");
263 Opc = isSub ? ARM::tSUBspi : ARM::tADDspi;
264 // FIXME: Fix Thumb1 immediate encoding.
265 BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
266 .addReg(BaseReg).addImm(ThisVal/4);
271 // sub rd, sp, so_imm
272 Opc = isSub ? ARM::t2SUBrSPi : ARM::t2ADDrSPi;
273 if (ARM_AM::getT2SOImmVal(NumBytes) != -1) {
276 // FIXME: Move this to ARMAddressingModes.h?
277 unsigned RotAmt = CountLeadingZeros_32(ThisVal);
278 ThisVal = ThisVal & ARM_AM::rotr32(0xff000000U, RotAmt);
279 NumBytes &= ~ThisVal;
280 assert(ARM_AM::getT2SOImmVal(ThisVal) != -1 &&
281 "Bit extraction didn't work?");
284 assert(DestReg != ARM::SP && BaseReg != ARM::SP);
285 Opc = isSub ? ARM::t2SUBri : ARM::t2ADDri;
286 if (ARM_AM::getT2SOImmVal(NumBytes) != -1) {
288 } else if (ThisVal < 4096) {
289 Opc = isSub ? ARM::t2SUBri12 : ARM::t2ADDri12;
292 // FIXME: Move this to ARMAddressingModes.h?
293 unsigned RotAmt = CountLeadingZeros_32(ThisVal);
294 ThisVal = ThisVal & ARM_AM::rotr32(0xff000000U, RotAmt);
295 NumBytes &= ~ThisVal;
296 assert(ARM_AM::getT2SOImmVal(ThisVal) != -1 &&
297 "Bit extraction didn't work?");
301 // Build the new ADD / SUB.
302 AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
303 .addReg(BaseReg, RegState::Kill)
311 negativeOffsetOpcode(unsigned opcode)
314 case ARM::t2LDRi12: return ARM::t2LDRi8;
315 case ARM::t2LDRHi12: return ARM::t2LDRHi8;
316 case ARM::t2LDRBi12: return ARM::t2LDRBi8;
317 case ARM::t2LDRSHi12: return ARM::t2LDRSHi8;
318 case ARM::t2LDRSBi12: return ARM::t2LDRSBi8;
319 case ARM::t2STRi12: return ARM::t2STRi8;
320 case ARM::t2STRBi12: return ARM::t2STRBi8;
321 case ARM::t2STRHi12: return ARM::t2STRHi8;
341 positiveOffsetOpcode(unsigned opcode)
344 case ARM::t2LDRi8: return ARM::t2LDRi12;
345 case ARM::t2LDRHi8: return ARM::t2LDRHi12;
346 case ARM::t2LDRBi8: return ARM::t2LDRBi12;
347 case ARM::t2LDRSHi8: return ARM::t2LDRSHi12;
348 case ARM::t2LDRSBi8: return ARM::t2LDRSBi12;
349 case ARM::t2STRi8: return ARM::t2STRi12;
350 case ARM::t2STRBi8: return ARM::t2STRBi12;
351 case ARM::t2STRHi8: return ARM::t2STRHi12;
356 case ARM::t2LDRSHi12:
357 case ARM::t2LDRSBi12:
371 immediateOffsetOpcode(unsigned opcode)
374 case ARM::t2LDRs: return ARM::t2LDRi12;
375 case ARM::t2LDRHs: return ARM::t2LDRHi12;
376 case ARM::t2LDRBs: return ARM::t2LDRBi12;
377 case ARM::t2LDRSHs: return ARM::t2LDRSHi12;
378 case ARM::t2LDRSBs: return ARM::t2LDRSBi12;
379 case ARM::t2STRs: return ARM::t2STRi12;
380 case ARM::t2STRBs: return ARM::t2STRBi12;
381 case ARM::t2STRHs: return ARM::t2STRHi12;
386 case ARM::t2LDRSHi12:
387 case ARM::t2LDRSBi12:
408 bool llvm::rewriteT2FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
409 unsigned FrameReg, int &Offset,
410 const ARMBaseInstrInfo &TII) {
411 unsigned Opcode = MI.getOpcode();
412 const TargetInstrDesc &Desc = MI.getDesc();
413 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
416 // Memory operands in inline assembly always use AddrModeT2_i12.
417 if (Opcode == ARM::INLINEASM)
418 AddrMode = ARMII::AddrModeT2_i12; // FIXME. mode for thumb2?
420 if (Opcode == ARM::t2ADDri || Opcode == ARM::t2ADDri12) {
421 Offset += MI.getOperand(FrameRegIdx+1).getImm();
423 bool isSP = FrameReg == ARM::SP;
425 // Turn it into a move.
426 MI.setDesc(TII.get(ARM::tMOVgpr2gpr));
427 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
428 MI.RemoveOperand(FrameRegIdx+1);
436 MI.setDesc(TII.get(isSP ? ARM::t2SUBrSPi : ARM::t2SUBri));
438 MI.setDesc(TII.get(isSP ? ARM::t2ADDrSPi : ARM::t2ADDri));
441 // Common case: small offset, fits into instruction.
442 if (ARM_AM::getT2SOImmVal(Offset) != -1) {
443 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
444 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
448 // Another common case: imm12.
450 unsigned NewOpc = isSP
451 ? (isSub ? ARM::t2SUBrSPi12 : ARM::t2ADDrSPi12)
452 : (isSub ? ARM::t2SUBri12 : ARM::t2ADDri12);
453 MI.setDesc(TII.get(NewOpc));
454 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
455 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
460 // Otherwise, extract 8 adjacent bits from the immediate into this
462 unsigned RotAmt = CountLeadingZeros_32(Offset);
463 unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xff000000U, RotAmt);
465 // We will handle these bits from offset, clear them.
466 Offset &= ~ThisImmVal;
468 assert(ARM_AM::getT2SOImmVal(ThisImmVal) != -1 &&
469 "Bit extraction didn't work?");
470 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(ThisImmVal);
473 // AddrMode4 cannot handle any offset.
474 if (AddrMode == ARMII::AddrMode4)
477 // AddrModeT2_so cannot handle any offset. If there is no offset
478 // register then we change to an immediate version.
479 unsigned NewOpc = Opcode;
480 if (AddrMode == ARMII::AddrModeT2_so) {
481 unsigned OffsetReg = MI.getOperand(FrameRegIdx+1).getReg();
482 if (OffsetReg != 0) {
483 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
487 MI.RemoveOperand(FrameRegIdx+1);
488 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(0);
489 NewOpc = immediateOffsetOpcode(Opcode);
490 AddrMode = ARMII::AddrModeT2_i12;
493 unsigned NumBits = 0;
495 if (AddrMode == ARMII::AddrModeT2_i8 || AddrMode == ARMII::AddrModeT2_i12) {
496 // i8 supports only negative, and i12 supports only positive, so
497 // based on Offset sign convert Opcode to the appropriate
499 Offset += MI.getOperand(FrameRegIdx+1).getImm();
501 NewOpc = negativeOffsetOpcode(Opcode);
506 NewOpc = positiveOffsetOpcode(Opcode);
510 // VFP and NEON address modes.
512 if (AddrMode == ARMII::AddrMode5) {
513 const MachineOperand &OffOp = MI.getOperand(FrameRegIdx+1);
514 InstrOffs = ARM_AM::getAM5Offset(OffOp.getImm());
515 if (ARM_AM::getAM5Op(OffOp.getImm()) == ARM_AM::sub)
520 Offset += InstrOffs * 4;
521 assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
528 if (NewOpc != Opcode)
529 MI.setDesc(TII.get(NewOpc));
531 MachineOperand &ImmOp = MI.getOperand(FrameRegIdx+1);
533 // Attempt to fold address computation
534 // Common case: small offset, fits into instruction.
535 int ImmedOffset = Offset / Scale;
536 unsigned Mask = (1 << NumBits) - 1;
537 if ((unsigned)Offset <= Mask * Scale) {
538 // Replace the FrameIndex with fp/sp
539 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
541 if (AddrMode == ARMII::AddrMode5)
542 // FIXME: Not consistent.
543 ImmedOffset |= 1 << NumBits;
545 ImmedOffset = -ImmedOffset;
547 ImmOp.ChangeToImmediate(ImmedOffset);
552 // Otherwise, offset doesn't fit. Pull in what we can to simplify
553 ImmedOffset = ImmedOffset & Mask;
555 if (AddrMode == ARMII::AddrMode5)
556 // FIXME: Not consistent.
557 ImmedOffset |= 1 << NumBits;
559 ImmedOffset = -ImmedOffset;
560 if (ImmedOffset == 0)
561 // Change the opcode back if the encoded offset is zero.
562 MI.setDesc(TII.get(positiveOffsetOpcode(NewOpc)));
565 ImmOp.ChangeToImmediate(ImmedOffset);
566 Offset &= ~(Mask*Scale);
569 Offset = (isSub) ? -Offset : Offset;