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/Constants.h"
21 #include "llvm/Function.h"
22 #include "llvm/GlobalValue.h"
23 #include "llvm/CodeGen/MachineConstantPool.h"
24 #include "llvm/CodeGen/MachineFrameInfo.h"
25 #include "llvm/CodeGen/MachineInstrBuilder.h"
26 #include "llvm/CodeGen/MachineMemOperand.h"
27 #include "llvm/CodeGen/PseudoSourceValue.h"
28 #include "llvm/ADT/SmallVector.h"
29 #include "Thumb2InstrInfo.h"
33 Thumb2InstrInfo::Thumb2InstrInfo(const ARMSubtarget &STI)
34 : ARMBaseInstrInfo(STI), RI(*this, STI) {
37 unsigned Thumb2InstrInfo::getUnindexedOpcode(unsigned Opc) const {
43 Thumb2InstrInfo::BlockHasNoFallThrough(const MachineBasicBlock &MBB) const {
44 if (MBB.empty()) return false;
46 switch (MBB.back().getOpcode()) {
48 case ARM::t2B: // Uncond branch.
49 case ARM::t2BR_JT: // Jumptable branch.
50 case ARM::t2TBB: // Table branch byte.
51 case ARM::t2TBH: // Table branch halfword.
52 case ARM::tBR_JTr: // Jumptable branch (16-bit version).
54 case ARM::tBX_RET_vararg:
67 Thumb2InstrInfo::copyRegToReg(MachineBasicBlock &MBB,
68 MachineBasicBlock::iterator I,
69 unsigned DestReg, unsigned SrcReg,
70 const TargetRegisterClass *DestRC,
71 const TargetRegisterClass *SrcRC) const {
72 DebugLoc DL = DebugLoc::getUnknownLoc();
73 if (I != MBB.end()) DL = I->getDebugLoc();
75 if (DestRC == ARM::GPRRegisterClass &&
76 SrcRC == ARM::GPRRegisterClass) {
77 BuildMI(MBB, I, DL, get(ARM::tMOVgpr2gpr), DestReg).addReg(SrcReg);
79 } else if (DestRC == ARM::GPRRegisterClass &&
80 SrcRC == ARM::tGPRRegisterClass) {
81 BuildMI(MBB, I, DL, get(ARM::tMOVtgpr2gpr), DestReg).addReg(SrcReg);
83 } else if (DestRC == ARM::tGPRRegisterClass &&
84 SrcRC == ARM::GPRRegisterClass) {
85 BuildMI(MBB, I, DL, get(ARM::tMOVgpr2tgpr), DestReg).addReg(SrcReg);
89 // Handle SPR, DPR, and QPR copies.
90 return ARMBaseInstrInfo::copyRegToReg(MBB, I, DestReg, SrcReg, DestRC, SrcRC);
93 void Thumb2InstrInfo::
94 storeRegToStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
95 unsigned SrcReg, bool isKill, int FI,
96 const TargetRegisterClass *RC) const {
97 DebugLoc DL = DebugLoc::getUnknownLoc();
98 if (I != MBB.end()) DL = I->getDebugLoc();
100 if (RC == ARM::GPRRegisterClass) {
101 MachineFunction &MF = *MBB.getParent();
102 MachineFrameInfo &MFI = *MF.getFrameInfo();
103 MachineMemOperand *MMO =
104 MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FI),
105 MachineMemOperand::MOStore, 0,
106 MFI.getObjectSize(FI),
107 MFI.getObjectAlignment(FI));
108 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::t2STRi12))
109 .addReg(SrcReg, getKillRegState(isKill))
110 .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
114 ARMBaseInstrInfo::storeRegToStackSlot(MBB, I, SrcReg, isKill, FI, RC);
117 void Thumb2InstrInfo::
118 loadRegFromStackSlot(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
119 unsigned DestReg, int FI,
120 const TargetRegisterClass *RC) const {
121 DebugLoc DL = DebugLoc::getUnknownLoc();
122 if (I != MBB.end()) DL = I->getDebugLoc();
124 if (RC == ARM::GPRRegisterClass) {
125 MachineFunction &MF = *MBB.getParent();
126 MachineFrameInfo &MFI = *MF.getFrameInfo();
127 MachineMemOperand *MMO =
128 MF.getMachineMemOperand(PseudoSourceValue::getFixedStack(FI),
129 MachineMemOperand::MOLoad, 0,
130 MFI.getObjectSize(FI),
131 MFI.getObjectAlignment(FI));
132 AddDefaultPred(BuildMI(MBB, I, DL, get(ARM::t2LDRi12), DestReg)
133 .addFrameIndex(FI).addImm(0).addMemOperand(MMO));
137 ARMBaseInstrInfo::loadRegFromStackSlot(MBB, I, DestReg, FI, RC);
140 void Thumb2InstrInfo::reMaterialize(MachineBasicBlock &MBB,
141 MachineBasicBlock::iterator I,
142 unsigned DestReg, unsigned SubIdx,
143 const MachineInstr *Orig) const {
144 DebugLoc dl = Orig->getDebugLoc();
145 unsigned Opcode = Orig->getOpcode();
148 MachineInstr *MI = MBB.getParent()->CloneMachineInstr(Orig);
149 MI->getOperand(0).setReg(DestReg);
153 case ARM::t2LDRpci_pic: {
154 MachineFunction &MF = *MBB.getParent();
155 ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
156 MachineConstantPool *MCP = MF.getConstantPool();
157 unsigned CPI = Orig->getOperand(1).getIndex();
158 const MachineConstantPoolEntry &MCPE = MCP->getConstants()[CPI];
159 assert(MCPE.isMachineConstantPoolEntry() &&
160 "Expecting a machine constantpool entry!");
161 ARMConstantPoolValue *ACPV =
162 static_cast<ARMConstantPoolValue*>(MCPE.Val.MachineCPVal);
163 unsigned PCLabelId = AFI->createConstPoolEntryUId();
164 ARMConstantPoolValue *NewCPV = 0;
165 if (ACPV->isGlobalValue())
166 NewCPV = new ARMConstantPoolValue(ACPV->getGV(), PCLabelId,
168 else if (ACPV->isExtSymbol())
169 NewCPV = new ARMConstantPoolValue(MF.getFunction()->getContext(),
170 ACPV->getSymbol(), PCLabelId, 4);
171 else if (ACPV->isBlockAddress())
172 NewCPV = new ARMConstantPoolValue(ACPV->getBlockAddress(), PCLabelId,
173 ARMCP::CPBlockAddress, 4);
175 llvm_unreachable("Unexpected ARM constantpool value type!!");
176 CPI = MCP->getConstantPoolIndex(NewCPV, MCPE.getAlignment());
177 MachineInstrBuilder MIB = BuildMI(MBB, I, Orig->getDebugLoc(), get(Opcode),
179 .addConstantPoolIndex(CPI).addImm(PCLabelId);
180 (*MIB).setMemRefs(Orig->memoperands_begin(), Orig->memoperands_end());
185 MachineInstr *NewMI = prior(I);
186 NewMI->getOperand(0).setSubReg(SubIdx);
189 void llvm::emitT2RegPlusImmediate(MachineBasicBlock &MBB,
190 MachineBasicBlock::iterator &MBBI, DebugLoc dl,
191 unsigned DestReg, unsigned BaseReg, int NumBytes,
192 ARMCC::CondCodes Pred, unsigned PredReg,
193 const ARMBaseInstrInfo &TII) {
194 bool isSub = NumBytes < 0;
195 if (isSub) NumBytes = -NumBytes;
197 // If profitable, use a movw or movt to materialize the offset.
198 // FIXME: Use the scavenger to grab a scratch register.
199 if (DestReg != ARM::SP && DestReg != BaseReg &&
201 ARM_AM::getT2SOImmVal(NumBytes) == -1) {
203 if (NumBytes < 65536) {
204 // Use a movw to materialize the 16-bit constant.
205 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2MOVi16), DestReg)
207 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
209 } else if ((NumBytes & 0xffff) == 0) {
210 // Use a movt to materialize the 32-bit constant.
211 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2MOVTi16), DestReg)
213 .addImm(NumBytes >> 16)
214 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
220 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2SUBrr), DestReg)
221 .addReg(BaseReg, RegState::Kill)
222 .addReg(DestReg, RegState::Kill)
223 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
225 BuildMI(MBB, MBBI, dl, TII.get(ARM::t2ADDrr), DestReg)
226 .addReg(DestReg, RegState::Kill)
227 .addReg(BaseReg, RegState::Kill)
228 .addImm((unsigned)Pred).addReg(PredReg).addReg(0);
235 unsigned ThisVal = NumBytes;
237 if (DestReg == ARM::SP && BaseReg != ARM::SP) {
238 // mov sp, rn. Note t2MOVr cannot be used.
239 BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2gpr),DestReg).addReg(BaseReg);
244 if (BaseReg == ARM::SP) {
246 if (DestReg == ARM::SP && (ThisVal < ((1 << 7)-1) * 4)) {
247 assert((ThisVal & 3) == 0 && "Stack update is not multiple of 4?");
248 Opc = isSub ? ARM::tSUBspi : ARM::tADDspi;
249 // FIXME: Fix Thumb1 immediate encoding.
250 BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
251 .addReg(BaseReg).addImm(ThisVal/4);
256 // sub rd, sp, so_imm
257 Opc = isSub ? ARM::t2SUBrSPi : ARM::t2ADDrSPi;
258 if (ARM_AM::getT2SOImmVal(NumBytes) != -1) {
261 // FIXME: Move this to ARMAddressingModes.h?
262 unsigned RotAmt = CountLeadingZeros_32(ThisVal);
263 ThisVal = ThisVal & ARM_AM::rotr32(0xff000000U, RotAmt);
264 NumBytes &= ~ThisVal;
265 assert(ARM_AM::getT2SOImmVal(ThisVal) != -1 &&
266 "Bit extraction didn't work?");
269 assert(DestReg != ARM::SP && BaseReg != ARM::SP);
270 Opc = isSub ? ARM::t2SUBri : ARM::t2ADDri;
271 if (ARM_AM::getT2SOImmVal(NumBytes) != -1) {
273 } else if (ThisVal < 4096) {
274 Opc = isSub ? ARM::t2SUBri12 : ARM::t2ADDri12;
277 // FIXME: Move this to ARMAddressingModes.h?
278 unsigned RotAmt = CountLeadingZeros_32(ThisVal);
279 ThisVal = ThisVal & ARM_AM::rotr32(0xff000000U, RotAmt);
280 NumBytes &= ~ThisVal;
281 assert(ARM_AM::getT2SOImmVal(ThisVal) != -1 &&
282 "Bit extraction didn't work?");
286 // Build the new ADD / SUB.
287 AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl, TII.get(Opc), DestReg)
288 .addReg(BaseReg, RegState::Kill)
296 negativeOffsetOpcode(unsigned opcode)
299 case ARM::t2LDRi12: return ARM::t2LDRi8;
300 case ARM::t2LDRHi12: return ARM::t2LDRHi8;
301 case ARM::t2LDRBi12: return ARM::t2LDRBi8;
302 case ARM::t2LDRSHi12: return ARM::t2LDRSHi8;
303 case ARM::t2LDRSBi12: return ARM::t2LDRSBi8;
304 case ARM::t2STRi12: return ARM::t2STRi8;
305 case ARM::t2STRBi12: return ARM::t2STRBi8;
306 case ARM::t2STRHi12: return ARM::t2STRHi8;
326 positiveOffsetOpcode(unsigned opcode)
329 case ARM::t2LDRi8: return ARM::t2LDRi12;
330 case ARM::t2LDRHi8: return ARM::t2LDRHi12;
331 case ARM::t2LDRBi8: return ARM::t2LDRBi12;
332 case ARM::t2LDRSHi8: return ARM::t2LDRSHi12;
333 case ARM::t2LDRSBi8: return ARM::t2LDRSBi12;
334 case ARM::t2STRi8: return ARM::t2STRi12;
335 case ARM::t2STRBi8: return ARM::t2STRBi12;
336 case ARM::t2STRHi8: return ARM::t2STRHi12;
341 case ARM::t2LDRSHi12:
342 case ARM::t2LDRSBi12:
356 immediateOffsetOpcode(unsigned opcode)
359 case ARM::t2LDRs: return ARM::t2LDRi12;
360 case ARM::t2LDRHs: return ARM::t2LDRHi12;
361 case ARM::t2LDRBs: return ARM::t2LDRBi12;
362 case ARM::t2LDRSHs: return ARM::t2LDRSHi12;
363 case ARM::t2LDRSBs: return ARM::t2LDRSBi12;
364 case ARM::t2STRs: return ARM::t2STRi12;
365 case ARM::t2STRBs: return ARM::t2STRBi12;
366 case ARM::t2STRHs: return ARM::t2STRHi12;
371 case ARM::t2LDRSHi12:
372 case ARM::t2LDRSBi12:
393 bool llvm::rewriteT2FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
394 unsigned FrameReg, int &Offset,
395 const ARMBaseInstrInfo &TII) {
396 unsigned Opcode = MI.getOpcode();
397 const TargetInstrDesc &Desc = MI.getDesc();
398 unsigned AddrMode = (Desc.TSFlags & ARMII::AddrModeMask);
401 // Memory operands in inline assembly always use AddrModeT2_i12.
402 if (Opcode == ARM::INLINEASM)
403 AddrMode = ARMII::AddrModeT2_i12; // FIXME. mode for thumb2?
405 if (Opcode == ARM::t2ADDri || Opcode == ARM::t2ADDri12) {
406 Offset += MI.getOperand(FrameRegIdx+1).getImm();
408 bool isSP = FrameReg == ARM::SP;
410 // Turn it into a move.
411 MI.setDesc(TII.get(ARM::tMOVgpr2gpr));
412 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
413 MI.RemoveOperand(FrameRegIdx+1);
421 MI.setDesc(TII.get(isSP ? ARM::t2SUBrSPi : ARM::t2SUBri));
423 MI.setDesc(TII.get(isSP ? ARM::t2ADDrSPi : ARM::t2ADDri));
426 // Common case: small offset, fits into instruction.
427 if (ARM_AM::getT2SOImmVal(Offset) != -1) {
428 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
429 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
433 // Another common case: imm12.
435 unsigned NewOpc = isSP
436 ? (isSub ? ARM::t2SUBrSPi12 : ARM::t2ADDrSPi12)
437 : (isSub ? ARM::t2SUBri12 : ARM::t2ADDri12);
438 MI.setDesc(TII.get(NewOpc));
439 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
440 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(Offset);
445 // Otherwise, extract 8 adjacent bits from the immediate into this
447 unsigned RotAmt = CountLeadingZeros_32(Offset);
448 unsigned ThisImmVal = Offset & ARM_AM::rotr32(0xff000000U, RotAmt);
450 // We will handle these bits from offset, clear them.
451 Offset &= ~ThisImmVal;
453 assert(ARM_AM::getT2SOImmVal(ThisImmVal) != -1 &&
454 "Bit extraction didn't work?");
455 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(ThisImmVal);
458 // AddrMode4 cannot handle any offset.
459 if (AddrMode == ARMII::AddrMode4)
462 // AddrModeT2_so cannot handle any offset. If there is no offset
463 // register then we change to an immediate version.
464 unsigned NewOpc = Opcode;
465 if (AddrMode == ARMII::AddrModeT2_so) {
466 unsigned OffsetReg = MI.getOperand(FrameRegIdx+1).getReg();
467 if (OffsetReg != 0) {
468 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
472 MI.RemoveOperand(FrameRegIdx+1);
473 MI.getOperand(FrameRegIdx+1).ChangeToImmediate(0);
474 NewOpc = immediateOffsetOpcode(Opcode);
475 AddrMode = ARMII::AddrModeT2_i12;
478 unsigned NumBits = 0;
480 if (AddrMode == ARMII::AddrModeT2_i8 || AddrMode == ARMII::AddrModeT2_i12) {
481 // i8 supports only negative, and i12 supports only positive, so
482 // based on Offset sign convert Opcode to the appropriate
484 Offset += MI.getOperand(FrameRegIdx+1).getImm();
486 NewOpc = negativeOffsetOpcode(Opcode);
491 NewOpc = positiveOffsetOpcode(Opcode);
495 // VFP and NEON address modes.
497 if (AddrMode == ARMII::AddrMode5) {
498 const MachineOperand &OffOp = MI.getOperand(FrameRegIdx+1);
499 InstrOffs = ARM_AM::getAM5Offset(OffOp.getImm());
500 if (ARM_AM::getAM5Op(OffOp.getImm()) == ARM_AM::sub)
505 Offset += InstrOffs * 4;
506 assert((Offset & (Scale-1)) == 0 && "Can't encode this offset!");
513 if (NewOpc != Opcode)
514 MI.setDesc(TII.get(NewOpc));
516 MachineOperand &ImmOp = MI.getOperand(FrameRegIdx+1);
518 // Attempt to fold address computation
519 // Common case: small offset, fits into instruction.
520 int ImmedOffset = Offset / Scale;
521 unsigned Mask = (1 << NumBits) - 1;
522 if ((unsigned)Offset <= Mask * Scale) {
523 // Replace the FrameIndex with fp/sp
524 MI.getOperand(FrameRegIdx).ChangeToRegister(FrameReg, false);
526 if (AddrMode == ARMII::AddrMode5)
527 // FIXME: Not consistent.
528 ImmedOffset |= 1 << NumBits;
530 ImmedOffset = -ImmedOffset;
532 ImmOp.ChangeToImmediate(ImmedOffset);
537 // Otherwise, offset doesn't fit. Pull in what we can to simplify
538 ImmedOffset = ImmedOffset & Mask;
540 if (AddrMode == ARMII::AddrMode5)
541 // FIXME: Not consistent.
542 ImmedOffset |= 1 << NumBits;
544 ImmedOffset = -ImmedOffset;
545 if (ImmedOffset == 0)
546 // Change the opcode back if the encoded offset is zero.
547 MI.setDesc(TII.get(positiveOffsetOpcode(NewOpc)));
550 ImmOp.ChangeToImmediate(ImmedOffset);
551 Offset &= ~(Mask*Scale);
554 Offset = (isSub) ? -Offset : Offset;