1 //===-- ARM/ARMMCCodeEmitter.cpp - Convert ARM code to machine code -------===//
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 implements the ARMMCCodeEmitter class.
12 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "arm-emitter"
16 #include "ARMAddressingModes.h"
17 #include "ARMFixupKinds.h"
18 #include "ARMInstrInfo.h"
19 #include "llvm/MC/MCCodeEmitter.h"
20 #include "llvm/MC/MCExpr.h"
21 #include "llvm/MC/MCInst.h"
22 #include "llvm/ADT/Statistic.h"
23 #include "llvm/Support/raw_ostream.h"
26 STATISTIC(MCNumEmitted, "Number of MC instructions emitted.");
27 STATISTIC(MCNumCPRelocations, "Number of constant pool relocations created.");
30 class ARMMCCodeEmitter : public MCCodeEmitter {
31 ARMMCCodeEmitter(const ARMMCCodeEmitter &); // DO NOT IMPLEMENT
32 void operator=(const ARMMCCodeEmitter &); // DO NOT IMPLEMENT
33 const TargetMachine &TM;
34 const TargetInstrInfo &TII;
38 ARMMCCodeEmitter(TargetMachine &tm, MCContext &ctx)
39 : TM(tm), TII(*TM.getInstrInfo()), Ctx(ctx) {
42 ~ARMMCCodeEmitter() {}
44 unsigned getNumFixupKinds() const { return ARM::NumTargetFixupKinds; }
46 const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
47 const static MCFixupKindInfo Infos[] = {
48 // name offset bits flags
49 { "fixup_arm_pcrel_12", 2, 12, MCFixupKindInfo::FKF_IsPCRel },
50 { "fixup_arm_vfp_pcrel_12", 3, 8, MCFixupKindInfo::FKF_IsPCRel },
51 { "fixup_arm_branch", 1, 24, MCFixupKindInfo::FKF_IsPCRel },
54 if (Kind < FirstTargetFixupKind)
55 return MCCodeEmitter::getFixupKindInfo(Kind);
57 assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
59 return Infos[Kind - FirstTargetFixupKind];
61 unsigned getMachineSoImmOpValue(unsigned SoImm) const;
63 // getBinaryCodeForInstr - TableGen'erated function for getting the
64 // binary encoding for an instruction.
65 unsigned getBinaryCodeForInstr(const MCInst &MI,
66 SmallVectorImpl<MCFixup> &Fixups) const;
68 /// getMachineOpValue - Return binary encoding of operand. If the machine
69 /// operand requires relocation, record the relocation and return zero.
70 unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
71 SmallVectorImpl<MCFixup> &Fixups) const;
73 bool EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx,
74 unsigned &Reg, unsigned &Imm,
75 SmallVectorImpl<MCFixup> &Fixups) const;
77 /// getBranchTargetOpValue - Return encoding info for 24-bit immediate
79 uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
80 SmallVectorImpl<MCFixup> &Fixups) const;
82 /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12'
84 uint32_t getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
85 SmallVectorImpl<MCFixup> &Fixups) const;
87 /// getLdStSORegOpValue - Return encoding info for 'reg +/- reg shop imm'
88 /// operand as needed by load/store instructions.
89 uint32_t getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
90 SmallVectorImpl<MCFixup> &Fixups) const;
92 /// getLdStmModeOpValue - Return encoding for load/store multiple mode.
93 uint32_t getLdStmModeOpValue(const MCInst &MI, unsigned OpIdx,
94 SmallVectorImpl<MCFixup> &Fixups) const {
95 ARM_AM::AMSubMode Mode = (ARM_AM::AMSubMode)MI.getOperand(OpIdx).getImm();
97 default: assert(0 && "Unknown addressing sub-mode!");
98 case ARM_AM::da: return 0;
99 case ARM_AM::ia: return 1;
100 case ARM_AM::db: return 2;
101 case ARM_AM::ib: return 3;
104 /// getAddrMode3OffsetOpValue - Return encoding for am3offset operands.
105 uint32_t getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
106 SmallVectorImpl<MCFixup> &Fixups) const;
108 /// getAddrMode3OpValue - Return encoding for addrmode3 operands.
109 uint32_t getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
110 SmallVectorImpl<MCFixup> &Fixups) const;
112 /// getAddrMode5OpValue - Return encoding info for 'reg +/- imm8' operand.
113 uint32_t getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
114 SmallVectorImpl<MCFixup> &Fixups) const;
116 /// getCCOutOpValue - Return encoding of the 's' bit.
117 unsigned getCCOutOpValue(const MCInst &MI, unsigned Op,
118 SmallVectorImpl<MCFixup> &Fixups) const {
119 // The operand is either reg0 or CPSR. The 's' bit is encoded as '0' or
121 return MI.getOperand(Op).getReg() == ARM::CPSR;
124 /// getSOImmOpValue - Return an encoded 12-bit shifted-immediate value.
125 unsigned getSOImmOpValue(const MCInst &MI, unsigned Op,
126 SmallVectorImpl<MCFixup> &Fixups) const {
127 unsigned SoImm = MI.getOperand(Op).getImm();
128 int SoImmVal = ARM_AM::getSOImmVal(SoImm);
129 assert(SoImmVal != -1 && "Not a valid so_imm value!");
131 // Encode rotate_imm.
132 unsigned Binary = (ARM_AM::getSOImmValRot((unsigned)SoImmVal) >> 1)
133 << ARMII::SoRotImmShift;
136 Binary |= ARM_AM::getSOImmValImm((unsigned)SoImmVal);
140 /// getSORegOpValue - Return an encoded so_reg shifted register value.
141 unsigned getSORegOpValue(const MCInst &MI, unsigned Op,
142 SmallVectorImpl<MCFixup> &Fixups) const;
144 unsigned getRotImmOpValue(const MCInst &MI, unsigned Op,
145 SmallVectorImpl<MCFixup> &Fixups) const {
146 switch (MI.getOperand(Op).getImm()) {
147 default: assert (0 && "Not a valid rot_imm value!");
155 unsigned getImmMinusOneOpValue(const MCInst &MI, unsigned Op,
156 SmallVectorImpl<MCFixup> &Fixups) const {
157 return MI.getOperand(Op).getImm() - 1;
160 unsigned getNEONVcvtImm32OpValue(const MCInst &MI, unsigned Op,
161 SmallVectorImpl<MCFixup> &Fixups) const {
162 return 64 - MI.getOperand(Op).getImm();
165 unsigned getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
166 SmallVectorImpl<MCFixup> &Fixups) const;
168 unsigned getRegisterListOpValue(const MCInst &MI, unsigned Op,
169 SmallVectorImpl<MCFixup> &Fixups) const;
170 unsigned getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
171 SmallVectorImpl<MCFixup> &Fixups) const;
172 unsigned getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
173 SmallVectorImpl<MCFixup> &Fixups) const;
175 unsigned NEONThumb2DataIPostEncoder(const MCInst &MI,
176 unsigned EncodedValue) const;
177 unsigned NEONThumb2LoadStorePostEncoder(const MCInst &MI,
178 unsigned EncodedValue) const;
179 unsigned NEONThumb2DupPostEncoder(const MCInst &MI,
180 unsigned EncodedValue) const;
182 void EmitByte(unsigned char C, raw_ostream &OS) const {
186 void EmitConstant(uint64_t Val, unsigned Size, raw_ostream &OS) const {
187 // Output the constant in little endian byte order.
188 for (unsigned i = 0; i != Size; ++i) {
189 EmitByte(Val & 255, OS);
194 void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
195 SmallVectorImpl<MCFixup> &Fixups) const;
198 } // end anonymous namespace
200 MCCodeEmitter *llvm::createARMMCCodeEmitter(const Target &, TargetMachine &TM,
202 return new ARMMCCodeEmitter(TM, Ctx);
205 /// NEONThumb2DataIPostEncoder - Post-process encoded NEON data-processing
206 /// instructions, and rewrite them to their Thumb2 form if we are currently in
208 unsigned ARMMCCodeEmitter::NEONThumb2DataIPostEncoder(const MCInst &MI,
209 unsigned EncodedValue) const {
210 const ARMSubtarget &Subtarget = TM.getSubtarget<ARMSubtarget>();
211 if (Subtarget.isThumb2()) {
212 // NEON Thumb2 data-processsing encodings are very simple: bit 24 is moved
213 // to bit 12 of the high half-word (i.e. bit 28), and bits 27-24 are
215 unsigned Bit24 = EncodedValue & 0x01000000;
216 unsigned Bit28 = Bit24 << 4;
217 EncodedValue &= 0xEFFFFFFF;
218 EncodedValue |= Bit28;
219 EncodedValue |= 0x0F000000;
225 /// NEONThumb2LoadStorePostEncoder - Post-process encoded NEON load/store
226 /// instructions, and rewrite them to their Thumb2 form if we are currently in
228 unsigned ARMMCCodeEmitter::NEONThumb2LoadStorePostEncoder(const MCInst &MI,
229 unsigned EncodedValue) const {
230 const ARMSubtarget &Subtarget = TM.getSubtarget<ARMSubtarget>();
231 if (Subtarget.isThumb2()) {
232 EncodedValue &= 0xF0FFFFFF;
233 EncodedValue |= 0x09000000;
239 /// NEONThumb2DupPostEncoder - Post-process encoded NEON vdup
240 /// instructions, and rewrite them to their Thumb2 form if we are currently in
242 unsigned ARMMCCodeEmitter::NEONThumb2DupPostEncoder(const MCInst &MI,
243 unsigned EncodedValue) const {
244 const ARMSubtarget &Subtarget = TM.getSubtarget<ARMSubtarget>();
245 if (Subtarget.isThumb2()) {
246 EncodedValue &= 0x00FFFFFF;
247 EncodedValue |= 0xEE000000;
255 /// getMachineOpValue - Return binary encoding of operand. If the machine
256 /// operand requires relocation, record the relocation and return zero.
257 unsigned ARMMCCodeEmitter::
258 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
259 SmallVectorImpl<MCFixup> &Fixups) const {
261 unsigned Reg = MO.getReg();
262 unsigned RegNo = getARMRegisterNumbering(Reg);
264 // Q registers are encodes as 2x their register number.
268 case ARM::Q0: case ARM::Q1: case ARM::Q2: case ARM::Q3:
269 case ARM::Q4: case ARM::Q5: case ARM::Q6: case ARM::Q7:
270 case ARM::Q8: case ARM::Q9: case ARM::Q10: case ARM::Q11:
271 case ARM::Q12: case ARM::Q13: case ARM::Q14: case ARM::Q15:
274 } else if (MO.isImm()) {
275 return static_cast<unsigned>(MO.getImm());
276 } else if (MO.isFPImm()) {
277 return static_cast<unsigned>(APFloat(MO.getFPImm())
278 .bitcastToAPInt().getHiBits(32).getLimitedValue());
288 /// getAddrModeImmOpValue - Return encoding info for 'reg +/- imm' operand.
289 bool ARMMCCodeEmitter::
290 EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx, unsigned &Reg,
291 unsigned &Imm, SmallVectorImpl<MCFixup> &Fixups) const {
292 const MCOperand &MO = MI.getOperand(OpIdx);
293 const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
295 Reg = getARMRegisterNumbering(MO.getReg());
297 int32_t SImm = MO1.getImm();
300 // Special value for #-0
301 if (SImm == INT32_MIN)
304 // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
314 /// getBranchTargetOpValue - Return encoding info for 24-bit immediate
316 uint32_t ARMMCCodeEmitter::
317 getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
318 SmallVectorImpl<MCFixup> &Fixups) const {
319 const MCOperand &MO = MI.getOperand(OpIdx);
321 // If the destination is an immediate, we have nothing to do.
322 if (MO.isImm()) return MO.getImm();
323 assert (MO.isExpr() && "Unexpected branch target type!");
324 const MCExpr *Expr = MO.getExpr();
325 MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_branch);
326 Fixups.push_back(MCFixup::Create(0, Expr, Kind));
328 // All of the information is in the fixup.
332 /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12' operand.
333 uint32_t ARMMCCodeEmitter::
334 getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
335 SmallVectorImpl<MCFixup> &Fixups) const {
337 // {12} = (U)nsigned (add == '1', sub == '0')
341 // If The first operand isn't a register, we have a label reference.
342 const MCOperand &MO = MI.getOperand(OpIdx);
344 Reg = getARMRegisterNumbering(ARM::PC); // Rn is PC.
347 assert(MO.isExpr() && "Unexpected machine operand type!");
348 const MCExpr *Expr = MO.getExpr();
349 MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_pcrel_12);
350 Fixups.push_back(MCFixup::Create(0, Expr, Kind));
352 ++MCNumCPRelocations;
354 isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm12, Fixups);
356 uint32_t Binary = Imm12 & 0xfff;
357 // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
360 Binary |= (Reg << 13);
364 uint32_t ARMMCCodeEmitter::
365 getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
366 SmallVectorImpl<MCFixup> &Fixups) const {
367 const MCOperand &MO = MI.getOperand(OpIdx);
368 const MCOperand &MO1 = MI.getOperand(OpIdx+1);
369 const MCOperand &MO2 = MI.getOperand(OpIdx+2);
370 unsigned Rn = getARMRegisterNumbering(MO.getReg());
371 unsigned Rm = getARMRegisterNumbering(MO1.getReg());
372 ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(MO2.getImm());
373 unsigned ShImm = ARM_AM::getAM2Offset(MO2.getImm());
374 bool isAdd = ARM_AM::getAM2Op(MO2.getImm()) == ARM_AM::add;
381 default: llvm_unreachable("Unknown shift opc!");
382 case ARM_AM::no_shift:
383 assert(ShImm == 0 && "Non-zero shift amount with no shift type!");
385 case ARM_AM::lsl: SBits = 0x0; break;
386 case ARM_AM::lsr: SBits = 0x1; break;
387 case ARM_AM::asr: SBits = 0x2; break;
388 case ARM_AM::ror: SBits = 0x3; break;
398 uint32_t Binary = Rm;
400 Binary |= SBits << 5;
401 Binary |= ShImm << 7;
407 uint32_t ARMMCCodeEmitter::
408 getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
409 SmallVectorImpl<MCFixup> &Fixups) const {
410 // {9} 1 == imm8, 0 == Rm
414 const MCOperand &MO = MI.getOperand(OpIdx);
415 const MCOperand &MO1 = MI.getOperand(OpIdx+1);
416 unsigned Imm = MO1.getImm();
417 bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
418 bool isImm = MO.getReg() == 0;
419 uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
420 // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
422 Imm8 = getARMRegisterNumbering(MO.getReg());
423 return Imm8 | (isAdd << 8) | (isImm << 9);
426 uint32_t ARMMCCodeEmitter::
427 getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
428 SmallVectorImpl<MCFixup> &Fixups) const {
429 // {13} 1 == imm8, 0 == Rm
434 const MCOperand &MO = MI.getOperand(OpIdx);
435 const MCOperand &MO1 = MI.getOperand(OpIdx+1);
436 const MCOperand &MO2 = MI.getOperand(OpIdx+2);
437 unsigned Rn = getARMRegisterNumbering(MO.getReg());
438 unsigned Imm = MO2.getImm();
439 bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
440 bool isImm = MO1.getReg() == 0;
441 uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
442 // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
444 Imm8 = getARMRegisterNumbering(MO1.getReg());
445 return (Rn << 9) | Imm8 | (isAdd << 8) | (isImm << 13);
448 /// getAddrMode5OpValue - Return encoding info for 'reg +/- imm12' operand.
449 uint32_t ARMMCCodeEmitter::
450 getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
451 SmallVectorImpl<MCFixup> &Fixups) const {
453 // {8} = (U)nsigned (add == '1', sub == '0')
456 // If The first operand isn't a register, we have a label reference.
457 const MCOperand &MO = MI.getOperand(OpIdx);
459 Reg = getARMRegisterNumbering(ARM::PC); // Rn is PC.
462 assert(MO.isExpr() && "Unexpected machine operand type!");
463 const MCExpr *Expr = MO.getExpr();
464 MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_vfp_pcrel_12);
465 Fixups.push_back(MCFixup::Create(0, Expr, Kind));
467 ++MCNumCPRelocations;
469 EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups);
471 uint32_t Binary = ARM_AM::getAM5Offset(Imm8);
472 // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
473 if (ARM_AM::getAM5Op(Imm8) == ARM_AM::add)
475 Binary |= (Reg << 9);
479 unsigned ARMMCCodeEmitter::
480 getSORegOpValue(const MCInst &MI, unsigned OpIdx,
481 SmallVectorImpl<MCFixup> &Fixups) const {
482 // Sub-operands are [reg, reg, imm]. The first register is Rm, the reg to be
483 // shifted. The second is either Rs, the amount to shift by, or reg0 in which
484 // case the imm contains the amount to shift by.
487 // {4} = 1 if reg shift, 0 if imm shift
495 const MCOperand &MO = MI.getOperand(OpIdx);
496 const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
497 const MCOperand &MO2 = MI.getOperand(OpIdx + 2);
498 ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO2.getImm());
501 unsigned Binary = getARMRegisterNumbering(MO.getReg());
503 // Encode the shift opcode.
505 unsigned Rs = MO1.getReg();
507 // Set shift operand (bit[7:4]).
512 // RRX - 0110 and bit[11:8] clear.
514 default: llvm_unreachable("Unknown shift opc!");
515 case ARM_AM::lsl: SBits = 0x1; break;
516 case ARM_AM::lsr: SBits = 0x3; break;
517 case ARM_AM::asr: SBits = 0x5; break;
518 case ARM_AM::ror: SBits = 0x7; break;
519 case ARM_AM::rrx: SBits = 0x6; break;
522 // Set shift operand (bit[6:4]).
528 default: llvm_unreachable("Unknown shift opc!");
529 case ARM_AM::lsl: SBits = 0x0; break;
530 case ARM_AM::lsr: SBits = 0x2; break;
531 case ARM_AM::asr: SBits = 0x4; break;
532 case ARM_AM::ror: SBits = 0x6; break;
536 Binary |= SBits << 4;
537 if (SOpc == ARM_AM::rrx)
540 // Encode the shift operation Rs or shift_imm (except rrx).
542 // Encode Rs bit[11:8].
543 assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
544 return Binary | (getARMRegisterNumbering(Rs) << ARMII::RegRsShift);
547 // Encode shift_imm bit[11:7].
548 return Binary | ARM_AM::getSORegOffset(MO2.getImm()) << 7;
551 unsigned ARMMCCodeEmitter::
552 getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
553 SmallVectorImpl<MCFixup> &Fixups) const {
554 // 10 bits. lower 5 bits are are the lsb of the mask, high five bits are the
556 const MCOperand &MO = MI.getOperand(Op);
557 uint32_t v = ~MO.getImm();
558 uint32_t lsb = CountTrailingZeros_32(v);
559 uint32_t msb = (32 - CountLeadingZeros_32 (v)) - 1;
560 assert (v != 0 && lsb < 32 && msb < 32 && "Illegal bitfield mask!");
561 return lsb | (msb << 5);
564 unsigned ARMMCCodeEmitter::
565 getRegisterListOpValue(const MCInst &MI, unsigned Op,
566 SmallVectorImpl<MCFixup> &Fixups) const {
567 // Convert a list of GPRs into a bitfield (R0 -> bit 0). For each
568 // register in the list, set the corresponding bit.
570 for (unsigned i = Op, e = MI.getNumOperands(); i < e; ++i) {
571 unsigned regno = getARMRegisterNumbering(MI.getOperand(i).getReg());
572 Binary |= 1 << regno;
577 unsigned ARMMCCodeEmitter::
578 getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
579 SmallVectorImpl<MCFixup> &Fixups) const {
580 const MCOperand &Reg = MI.getOperand(Op);
581 const MCOperand &Imm = MI.getOperand(Op + 1);
583 unsigned RegNo = getARMRegisterNumbering(Reg.getReg());
586 switch (Imm.getImm()) {
590 case 8: Align = 0x01; break;
591 case 16: Align = 0x02; break;
592 case 32: Align = 0x03; break;
595 return RegNo | (Align << 4);
598 unsigned ARMMCCodeEmitter::
599 getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
600 SmallVectorImpl<MCFixup> &Fixups) const {
601 const MCOperand &MO = MI.getOperand(Op);
602 if (MO.getReg() == 0) return 0x0D;
606 void ARMMCCodeEmitter::
607 EncodeInstruction(const MCInst &MI, raw_ostream &OS,
608 SmallVectorImpl<MCFixup> &Fixups) const {
609 // Pseudo instructions don't get encoded.
610 const TargetInstrDesc &Desc = TII.get(MI.getOpcode());
611 if ((Desc.TSFlags & ARMII::FormMask) == ARMII::Pseudo)
614 EmitConstant(getBinaryCodeForInstr(MI, Fixups), 4, OS);
615 ++MCNumEmitted; // Keep track of the # of mi's emitted.
618 #include "ARMGenMCCodeEmitter.inc"