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 2; }
46 const MCFixupKindInfo &getFixupKindInfo(MCFixupKind Kind) const {
47 const static MCFixupKindInfo Infos[] = {
48 { "fixup_arm_pcrel_12", 2, 12, MCFixupKindInfo::FKF_IsPCRel },
49 { "fixup_arm_vfp_pcrel_12", 3, 8, MCFixupKindInfo::FKF_IsPCRel },
52 if (Kind < FirstTargetFixupKind)
53 return MCCodeEmitter::getFixupKindInfo(Kind);
55 assert(unsigned(Kind - FirstTargetFixupKind) < getNumFixupKinds() &&
57 return Infos[Kind - FirstTargetFixupKind];
59 unsigned getMachineSoImmOpValue(unsigned SoImm) const;
61 // getBinaryCodeForInstr - TableGen'erated function for getting the
62 // binary encoding for an instruction.
63 unsigned getBinaryCodeForInstr(const MCInst &MI,
64 SmallVectorImpl<MCFixup> &Fixups) const;
66 /// getMachineOpValue - Return binary encoding of operand. If the machine
67 /// operand requires relocation, record the relocation and return zero.
68 unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
69 SmallVectorImpl<MCFixup> &Fixups) const;
71 bool EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx,
72 unsigned &Reg, unsigned &Imm,
73 SmallVectorImpl<MCFixup> &Fixups) const;
75 /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12'
77 uint32_t getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
78 SmallVectorImpl<MCFixup> &Fixups) const;
80 /// getLdStSORegOpValue - Return encoding info for 'reg +/- reg shop imm'
81 /// operand as needed by load/store instructions.
82 uint32_t getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
83 SmallVectorImpl<MCFixup> &Fixups) const;
85 /// getLdStmModeOpValue - Return encoding for load/store multiple mode.
86 uint32_t getLdStmModeOpValue(const MCInst &MI, unsigned OpIdx,
87 SmallVectorImpl<MCFixup> &Fixups) const {
88 ARM_AM::AMSubMode Mode = (ARM_AM::AMSubMode)MI.getOperand(OpIdx).getImm();
90 default: assert(0 && "Unknown addressing sub-mode!");
91 case ARM_AM::da: return 0;
92 case ARM_AM::ia: return 1;
93 case ARM_AM::db: return 2;
94 case ARM_AM::ib: return 3;
97 /// getAddrMode3OffsetOpValue - Return encoding for am3offset operands.
98 uint32_t getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
99 SmallVectorImpl<MCFixup> &Fixups) const;
101 /// getAddrMode3OpValue - Return encoding for addrmode3 operands.
102 uint32_t getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
103 SmallVectorImpl<MCFixup> &Fixups) const;
105 /// getAddrMode5OpValue - Return encoding info for 'reg +/- imm8' operand.
106 uint32_t getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
107 SmallVectorImpl<MCFixup> &Fixups) const;
109 /// getCCOutOpValue - Return encoding of the 's' bit.
110 unsigned getCCOutOpValue(const MCInst &MI, unsigned Op,
111 SmallVectorImpl<MCFixup> &Fixups) const {
112 // The operand is either reg0 or CPSR. The 's' bit is encoded as '0' or
114 return MI.getOperand(Op).getReg() == ARM::CPSR;
117 /// getSOImmOpValue - Return an encoded 12-bit shifted-immediate value.
118 unsigned getSOImmOpValue(const MCInst &MI, unsigned Op,
119 SmallVectorImpl<MCFixup> &Fixups) const {
120 unsigned SoImm = MI.getOperand(Op).getImm();
121 int SoImmVal = ARM_AM::getSOImmVal(SoImm);
122 assert(SoImmVal != -1 && "Not a valid so_imm value!");
124 // Encode rotate_imm.
125 unsigned Binary = (ARM_AM::getSOImmValRot((unsigned)SoImmVal) >> 1)
126 << ARMII::SoRotImmShift;
129 Binary |= ARM_AM::getSOImmValImm((unsigned)SoImmVal);
133 /// getSORegOpValue - Return an encoded so_reg shifted register value.
134 unsigned getSORegOpValue(const MCInst &MI, unsigned Op,
135 SmallVectorImpl<MCFixup> &Fixups) const;
137 unsigned getRotImmOpValue(const MCInst &MI, unsigned Op,
138 SmallVectorImpl<MCFixup> &Fixups) const {
139 switch (MI.getOperand(Op).getImm()) {
140 default: assert (0 && "Not a valid rot_imm value!");
148 unsigned getImmMinusOneOpValue(const MCInst &MI, unsigned Op,
149 SmallVectorImpl<MCFixup> &Fixups) const {
150 return MI.getOperand(Op).getImm() - 1;
153 unsigned getNEONVcvtImm32OpValue(const MCInst &MI, unsigned Op,
154 SmallVectorImpl<MCFixup> &Fixups) const {
155 return 64 - MI.getOperand(Op).getImm();
158 unsigned getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
159 SmallVectorImpl<MCFixup> &Fixups) const;
161 unsigned getRegisterListOpValue(const MCInst &MI, unsigned Op,
162 SmallVectorImpl<MCFixup> &Fixups) const;
163 unsigned getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
164 SmallVectorImpl<MCFixup> &Fixups) const;
165 unsigned getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
166 SmallVectorImpl<MCFixup> &Fixups) const;
168 void EmitByte(unsigned char C, raw_ostream &OS) const {
172 void EmitConstant(uint64_t Val, unsigned Size, raw_ostream &OS) const {
173 // Output the constant in little endian byte order.
174 for (unsigned i = 0; i != Size; ++i) {
175 EmitByte(Val & 255, OS);
180 void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
181 SmallVectorImpl<MCFixup> &Fixups) const;
184 } // end anonymous namespace
186 MCCodeEmitter *llvm::createARMMCCodeEmitter(const Target &, TargetMachine &TM,
188 return new ARMMCCodeEmitter(TM, Ctx);
191 /// getMachineOpValue - Return binary encoding of operand. If the machine
192 /// operand requires relocation, record the relocation and return zero.
193 unsigned ARMMCCodeEmitter::
194 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
195 SmallVectorImpl<MCFixup> &Fixups) const {
197 unsigned Reg = MO.getReg();
198 unsigned RegNo = getARMRegisterNumbering(Reg);
200 // Q registers are encodes as 2x their register number.
204 case ARM::Q0: case ARM::Q1: case ARM::Q2: case ARM::Q3:
205 case ARM::Q4: case ARM::Q5: case ARM::Q6: case ARM::Q7:
206 case ARM::Q8: case ARM::Q9: case ARM::Q10: case ARM::Q11:
207 case ARM::Q12: case ARM::Q13: case ARM::Q14: case ARM::Q15:
210 } else if (MO.isImm()) {
211 return static_cast<unsigned>(MO.getImm());
212 } else if (MO.isFPImm()) {
213 return static_cast<unsigned>(APFloat(MO.getFPImm())
214 .bitcastToAPInt().getHiBits(32).getLimitedValue());
224 /// getAddrModeImmOpValue - Return encoding info for 'reg +/- imm' operand.
225 bool ARMMCCodeEmitter::
226 EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx, unsigned &Reg,
227 unsigned &Imm, SmallVectorImpl<MCFixup> &Fixups) const {
228 const MCOperand &MO = MI.getOperand(OpIdx);
229 const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
231 Reg = getARMRegisterNumbering(MO.getReg());
233 int32_t SImm = MO1.getImm();
236 // Special value for #-0
237 if (SImm == INT32_MIN)
240 // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
250 /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12' operand.
251 uint32_t ARMMCCodeEmitter::
252 getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
253 SmallVectorImpl<MCFixup> &Fixups) const {
255 // {12} = (U)nsigned (add == '1', sub == '0')
259 // If The first operand isn't a register, we have a label reference.
260 const MCOperand &MO = MI.getOperand(OpIdx);
262 Reg = getARMRegisterNumbering(ARM::PC); // Rn is PC.
265 assert(MO.isExpr() && "Unexpected machine operand type!");
266 const MCExpr *Expr = MO.getExpr();
267 MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_pcrel_12);
268 Fixups.push_back(MCFixup::Create(0, Expr, Kind));
270 ++MCNumCPRelocations;
272 isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm12, Fixups);
274 uint32_t Binary = Imm12 & 0xfff;
275 // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
278 Binary |= (Reg << 13);
282 uint32_t ARMMCCodeEmitter::
283 getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
284 SmallVectorImpl<MCFixup> &Fixups) const {
285 const MCOperand &MO = MI.getOperand(OpIdx);
286 const MCOperand &MO1 = MI.getOperand(OpIdx+1);
287 const MCOperand &MO2 = MI.getOperand(OpIdx+2);
288 unsigned Rn = getARMRegisterNumbering(MO.getReg());
289 unsigned Rm = getARMRegisterNumbering(MO1.getReg());
290 ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(MO2.getImm());
291 unsigned ShImm = ARM_AM::getAM2Offset(MO2.getImm());
292 bool isAdd = ARM_AM::getAM2Op(MO2.getImm()) == ARM_AM::add;
299 default: llvm_unreachable("Unknown shift opc!");
300 case ARM_AM::no_shift:
301 assert(ShImm == 0 && "Non-zero shift amount with no shift type!");
303 case ARM_AM::lsl: SBits = 0x0; break;
304 case ARM_AM::lsr: SBits = 0x1; break;
305 case ARM_AM::asr: SBits = 0x2; break;
306 case ARM_AM::ror: SBits = 0x3; break;
316 uint32_t Binary = Rm;
318 Binary |= SBits << 5;
319 Binary |= ShImm << 7;
325 uint32_t ARMMCCodeEmitter::
326 getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
327 SmallVectorImpl<MCFixup> &Fixups) const {
328 // {9} 1 == imm8, 0 == Rm
332 const MCOperand &MO = MI.getOperand(OpIdx);
333 const MCOperand &MO1 = MI.getOperand(OpIdx+1);
334 unsigned Imm = MO1.getImm();
335 bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
336 bool isImm = MO.getReg() == 0;
337 uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
338 // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
340 Imm8 = getARMRegisterNumbering(MO.getReg());
341 return Imm8 | (isAdd << 8) | (isImm << 9);
344 uint32_t ARMMCCodeEmitter::
345 getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
346 SmallVectorImpl<MCFixup> &Fixups) const {
347 // {13} 1 == imm8, 0 == Rm
352 const MCOperand &MO = MI.getOperand(OpIdx);
353 const MCOperand &MO1 = MI.getOperand(OpIdx+1);
354 const MCOperand &MO2 = MI.getOperand(OpIdx+2);
355 unsigned Rn = getARMRegisterNumbering(MO.getReg());
356 unsigned Imm = MO2.getImm();
357 bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
358 bool isImm = MO1.getReg() == 0;
359 uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
360 // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
362 Imm8 = getARMRegisterNumbering(MO1.getReg());
363 return (Rn << 9) | Imm8 | (isAdd << 8) | (isImm << 13);
366 /// getAddrMode5OpValue - Return encoding info for 'reg +/- imm12' operand.
367 uint32_t ARMMCCodeEmitter::
368 getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
369 SmallVectorImpl<MCFixup> &Fixups) const {
371 // {8} = (U)nsigned (add == '1', sub == '0')
374 // If The first operand isn't a register, we have a label reference.
375 const MCOperand &MO = MI.getOperand(OpIdx);
377 Reg = getARMRegisterNumbering(ARM::PC); // Rn is PC.
380 assert(MO.isExpr() && "Unexpected machine operand type!");
381 const MCExpr *Expr = MO.getExpr();
382 MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_vfp_pcrel_12);
383 Fixups.push_back(MCFixup::Create(0, Expr, Kind));
385 ++MCNumCPRelocations;
387 EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups);
389 uint32_t Binary = ARM_AM::getAM5Offset(Imm8);
390 // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
391 if (ARM_AM::getAM5Op(Imm8) == ARM_AM::add)
393 Binary |= (Reg << 9);
397 unsigned ARMMCCodeEmitter::
398 getSORegOpValue(const MCInst &MI, unsigned OpIdx,
399 SmallVectorImpl<MCFixup> &Fixups) const {
400 // Sub-operands are [reg, reg, imm]. The first register is Rm, the reg to be
401 // shifted. The second is either Rs, the amount to shift by, or reg0 in which
402 // case the imm contains the amount to shift by.
405 // {4} = 1 if reg shift, 0 if imm shift
413 const MCOperand &MO = MI.getOperand(OpIdx);
414 const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
415 const MCOperand &MO2 = MI.getOperand(OpIdx + 2);
416 ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO2.getImm());
419 unsigned Binary = getARMRegisterNumbering(MO.getReg());
421 // Encode the shift opcode.
423 unsigned Rs = MO1.getReg();
425 // Set shift operand (bit[7:4]).
430 // RRX - 0110 and bit[11:8] clear.
432 default: llvm_unreachable("Unknown shift opc!");
433 case ARM_AM::lsl: SBits = 0x1; break;
434 case ARM_AM::lsr: SBits = 0x3; break;
435 case ARM_AM::asr: SBits = 0x5; break;
436 case ARM_AM::ror: SBits = 0x7; break;
437 case ARM_AM::rrx: SBits = 0x6; break;
440 // Set shift operand (bit[6:4]).
446 default: llvm_unreachable("Unknown shift opc!");
447 case ARM_AM::lsl: SBits = 0x0; break;
448 case ARM_AM::lsr: SBits = 0x2; break;
449 case ARM_AM::asr: SBits = 0x4; break;
450 case ARM_AM::ror: SBits = 0x6; break;
454 Binary |= SBits << 4;
455 if (SOpc == ARM_AM::rrx)
458 // Encode the shift operation Rs or shift_imm (except rrx).
460 // Encode Rs bit[11:8].
461 assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
462 return Binary | (getARMRegisterNumbering(Rs) << ARMII::RegRsShift);
465 // Encode shift_imm bit[11:7].
466 return Binary | ARM_AM::getSORegOffset(MO2.getImm()) << 7;
469 unsigned ARMMCCodeEmitter::
470 getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
471 SmallVectorImpl<MCFixup> &Fixups) const {
472 // 10 bits. lower 5 bits are are the lsb of the mask, high five bits are the
474 const MCOperand &MO = MI.getOperand(Op);
475 uint32_t v = ~MO.getImm();
476 uint32_t lsb = CountTrailingZeros_32(v);
477 uint32_t msb = (32 - CountLeadingZeros_32 (v)) - 1;
478 assert (v != 0 && lsb < 32 && msb < 32 && "Illegal bitfield mask!");
479 return lsb | (msb << 5);
482 unsigned ARMMCCodeEmitter::
483 getRegisterListOpValue(const MCInst &MI, unsigned Op,
484 SmallVectorImpl<MCFixup> &Fixups) const {
485 // Convert a list of GPRs into a bitfield (R0 -> bit 0). For each
486 // register in the list, set the corresponding bit.
488 for (unsigned i = Op, e = MI.getNumOperands(); i < e; ++i) {
489 unsigned regno = getARMRegisterNumbering(MI.getOperand(i).getReg());
490 Binary |= 1 << regno;
495 unsigned ARMMCCodeEmitter::
496 getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
497 SmallVectorImpl<MCFixup> &Fixups) const {
498 const MCOperand &Reg = MI.getOperand(Op);
499 const MCOperand &Imm = MI.getOperand(Op + 1);
501 unsigned RegNo = getARMRegisterNumbering(Reg.getReg());
504 switch (Imm.getImm()) {
508 case 8: Align = 0x01; break;
509 case 16: Align = 0x02; break;
510 case 32: Align = 0x03; break;
513 return RegNo | (Align << 4);
516 unsigned ARMMCCodeEmitter::
517 getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
518 SmallVectorImpl<MCFixup> &Fixups) const {
519 const MCOperand &MO = MI.getOperand(Op);
520 if (MO.getReg() == 0) return 0x0D;
524 void ARMMCCodeEmitter::
525 EncodeInstruction(const MCInst &MI, raw_ostream &OS,
526 SmallVectorImpl<MCFixup> &Fixups) const {
527 // Pseudo instructions don't get encoded.
528 const TargetInstrDesc &Desc = TII.get(MI.getOpcode());
529 if ((Desc.TSFlags & ARMII::FormMask) == ARMII::Pseudo)
532 EmitConstant(getBinaryCodeForInstr(MI, Fixups), 4, OS);
533 ++MCNumEmitted; // Keep track of the # of mi's emitted.
536 #include "ARMGenMCCodeEmitter.inc"