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;
98 /// getAddrMode5OpValue - Return encoding info for 'reg +/- imm8' operand.
99 uint32_t getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
100 SmallVectorImpl<MCFixup> &Fixups) const;
102 /// getCCOutOpValue - Return encoding of the 's' bit.
103 unsigned getCCOutOpValue(const MCInst &MI, unsigned Op,
104 SmallVectorImpl<MCFixup> &Fixups) const {
105 // The operand is either reg0 or CPSR. The 's' bit is encoded as '0' or
107 return MI.getOperand(Op).getReg() == ARM::CPSR;
110 /// getSOImmOpValue - Return an encoded 12-bit shifted-immediate value.
111 unsigned getSOImmOpValue(const MCInst &MI, unsigned Op,
112 SmallVectorImpl<MCFixup> &Fixups) const {
113 unsigned SoImm = MI.getOperand(Op).getImm();
114 int SoImmVal = ARM_AM::getSOImmVal(SoImm);
115 assert(SoImmVal != -1 && "Not a valid so_imm value!");
117 // Encode rotate_imm.
118 unsigned Binary = (ARM_AM::getSOImmValRot((unsigned)SoImmVal) >> 1)
119 << ARMII::SoRotImmShift;
122 Binary |= ARM_AM::getSOImmValImm((unsigned)SoImmVal);
126 /// getSORegOpValue - Return an encoded so_reg shifted register value.
127 unsigned getSORegOpValue(const MCInst &MI, unsigned Op,
128 SmallVectorImpl<MCFixup> &Fixups) const;
130 unsigned getRotImmOpValue(const MCInst &MI, unsigned Op,
131 SmallVectorImpl<MCFixup> &Fixups) const {
132 switch (MI.getOperand(Op).getImm()) {
133 default: assert (0 && "Not a valid rot_imm value!");
141 unsigned getImmMinusOneOpValue(const MCInst &MI, unsigned Op,
142 SmallVectorImpl<MCFixup> &Fixups) const {
143 return MI.getOperand(Op).getImm() - 1;
146 unsigned getNEONVcvtImm32OpValue(const MCInst &MI, unsigned Op,
147 SmallVectorImpl<MCFixup> &Fixups) const {
148 return 64 - MI.getOperand(Op).getImm();
151 unsigned getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
152 SmallVectorImpl<MCFixup> &Fixups) const;
154 unsigned getRegisterListOpValue(const MCInst &MI, unsigned Op,
155 SmallVectorImpl<MCFixup> &Fixups) const;
156 unsigned getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
157 SmallVectorImpl<MCFixup> &Fixups) const;
158 unsigned getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
159 SmallVectorImpl<MCFixup> &Fixups) const;
161 void EmitByte(unsigned char C, raw_ostream &OS) const {
165 void EmitConstant(uint64_t Val, unsigned Size, raw_ostream &OS) const {
166 // Output the constant in little endian byte order.
167 for (unsigned i = 0; i != Size; ++i) {
168 EmitByte(Val & 255, OS);
173 void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
174 SmallVectorImpl<MCFixup> &Fixups) const;
177 } // end anonymous namespace
179 MCCodeEmitter *llvm::createARMMCCodeEmitter(const Target &, TargetMachine &TM,
181 return new ARMMCCodeEmitter(TM, Ctx);
184 /// getMachineOpValue - Return binary encoding of operand. If the machine
185 /// operand requires relocation, record the relocation and return zero.
186 unsigned ARMMCCodeEmitter::
187 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
188 SmallVectorImpl<MCFixup> &Fixups) const {
190 unsigned Reg = MO.getReg();
191 unsigned RegNo = getARMRegisterNumbering(Reg);
193 // Q registers are encodes as 2x their register number.
197 case ARM::Q0: case ARM::Q1: case ARM::Q2: case ARM::Q3:
198 case ARM::Q4: case ARM::Q5: case ARM::Q6: case ARM::Q7:
199 case ARM::Q8: case ARM::Q9: case ARM::Q10: case ARM::Q11:
200 case ARM::Q12: case ARM::Q13: case ARM::Q14: case ARM::Q15:
203 } else if (MO.isImm()) {
204 return static_cast<unsigned>(MO.getImm());
205 } else if (MO.isFPImm()) {
206 return static_cast<unsigned>(APFloat(MO.getFPImm())
207 .bitcastToAPInt().getHiBits(32).getLimitedValue());
217 /// getAddrModeImmOpValue - Return encoding info for 'reg +/- imm' operand.
218 bool ARMMCCodeEmitter::
219 EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx, unsigned &Reg,
220 unsigned &Imm, SmallVectorImpl<MCFixup> &Fixups) const {
221 const MCOperand &MO = MI.getOperand(OpIdx);
222 const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
224 Reg = getARMRegisterNumbering(MO.getReg());
226 int32_t SImm = MO1.getImm();
229 // Special value for #-0
230 if (SImm == INT32_MIN)
233 // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
243 /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12' operand.
244 uint32_t ARMMCCodeEmitter::
245 getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
246 SmallVectorImpl<MCFixup> &Fixups) const {
248 // {12} = (U)nsigned (add == '1', sub == '0')
252 // If The first operand isn't a register, we have a label reference.
253 const MCOperand &MO = MI.getOperand(OpIdx);
255 Reg = getARMRegisterNumbering(ARM::PC); // Rn is PC.
258 assert(MO.isExpr() && "Unexpected machine operand type!");
259 const MCExpr *Expr = MO.getExpr();
260 MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_pcrel_12);
261 Fixups.push_back(MCFixup::Create(0, Expr, Kind));
263 ++MCNumCPRelocations;
265 isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm12, Fixups);
267 uint32_t Binary = Imm12 & 0xfff;
268 // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
271 Binary |= (Reg << 13);
275 uint32_t ARMMCCodeEmitter::
276 getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
277 SmallVectorImpl<MCFixup> &Fixups) const {
278 const MCOperand &MO = MI.getOperand(OpIdx);
279 const MCOperand &MO1 = MI.getOperand(OpIdx+1);
280 const MCOperand &MO2 = MI.getOperand(OpIdx+2);
281 unsigned Rn = getARMRegisterNumbering(MO.getReg());
282 unsigned Rm = getARMRegisterNumbering(MO1.getReg());
283 ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(MO2.getImm());
284 unsigned ShImm = ARM_AM::getAM2Offset(MO2.getImm());
285 bool isAdd = ARM_AM::getAM2Op(MO2.getImm()) == ARM_AM::add;
292 default: llvm_unreachable("Unknown shift opc!");
293 case ARM_AM::no_shift:
294 assert(ShImm == 0 && "Non-zero shift amount with no shift type!");
296 case ARM_AM::lsl: SBits = 0x0; break;
297 case ARM_AM::lsr: SBits = 0x1; break;
298 case ARM_AM::asr: SBits = 0x2; break;
299 case ARM_AM::ror: SBits = 0x3; break;
311 Binary |= SBits << 5;
312 Binary |= ShImm << 7;
318 /// getAddrMode5OpValue - Return encoding info for 'reg +/- imm12' operand.
319 uint32_t ARMMCCodeEmitter::
320 getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
321 SmallVectorImpl<MCFixup> &Fixups) const {
323 // {8} = (U)nsigned (add == '1', sub == '0')
326 // If The first operand isn't a register, we have a label reference.
327 const MCOperand &MO = MI.getOperand(OpIdx);
329 Reg = getARMRegisterNumbering(ARM::PC); // Rn is PC.
332 assert(MO.isExpr() && "Unexpected machine operand type!");
333 const MCExpr *Expr = MO.getExpr();
334 MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_vfp_pcrel_12);
335 Fixups.push_back(MCFixup::Create(0, Expr, Kind));
337 ++MCNumCPRelocations;
339 EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups);
341 uint32_t Binary = ARM_AM::getAM5Offset(Imm8);
342 // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
343 if (ARM_AM::getAM5Op(Imm8) == ARM_AM::add)
345 Binary |= (Reg << 9);
349 unsigned ARMMCCodeEmitter::
350 getSORegOpValue(const MCInst &MI, unsigned OpIdx,
351 SmallVectorImpl<MCFixup> &Fixups) const {
352 // Sub-operands are [reg, reg, imm]. The first register is Rm, the reg to be
353 // shifted. The second is either Rs, the amount to shift by, or reg0 in which
354 // case the imm contains the amount to shift by.
357 // {4} = 1 if reg shift, 0 if imm shift
365 const MCOperand &MO = MI.getOperand(OpIdx);
366 const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
367 const MCOperand &MO2 = MI.getOperand(OpIdx + 2);
368 ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO2.getImm());
371 unsigned Binary = getARMRegisterNumbering(MO.getReg());
373 // Encode the shift opcode.
375 unsigned Rs = MO1.getReg();
377 // Set shift operand (bit[7:4]).
382 // RRX - 0110 and bit[11:8] clear.
384 default: llvm_unreachable("Unknown shift opc!");
385 case ARM_AM::lsl: SBits = 0x1; break;
386 case ARM_AM::lsr: SBits = 0x3; break;
387 case ARM_AM::asr: SBits = 0x5; break;
388 case ARM_AM::ror: SBits = 0x7; break;
389 case ARM_AM::rrx: SBits = 0x6; break;
392 // Set shift operand (bit[6:4]).
398 default: llvm_unreachable("Unknown shift opc!");
399 case ARM_AM::lsl: SBits = 0x0; break;
400 case ARM_AM::lsr: SBits = 0x2; break;
401 case ARM_AM::asr: SBits = 0x4; break;
402 case ARM_AM::ror: SBits = 0x6; break;
406 Binary |= SBits << 4;
407 if (SOpc == ARM_AM::rrx)
410 // Encode the shift operation Rs or shift_imm (except rrx).
412 // Encode Rs bit[11:8].
413 assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
414 return Binary | (getARMRegisterNumbering(Rs) << ARMII::RegRsShift);
417 // Encode shift_imm bit[11:7].
418 return Binary | ARM_AM::getSORegOffset(MO2.getImm()) << 7;
421 unsigned ARMMCCodeEmitter::
422 getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
423 SmallVectorImpl<MCFixup> &Fixups) const {
424 // 10 bits. lower 5 bits are are the lsb of the mask, high five bits are the
426 const MCOperand &MO = MI.getOperand(Op);
427 uint32_t v = ~MO.getImm();
428 uint32_t lsb = CountTrailingZeros_32(v);
429 uint32_t msb = (32 - CountLeadingZeros_32 (v)) - 1;
430 assert (v != 0 && lsb < 32 && msb < 32 && "Illegal bitfield mask!");
431 return lsb | (msb << 5);
434 unsigned ARMMCCodeEmitter::
435 getRegisterListOpValue(const MCInst &MI, unsigned Op,
436 SmallVectorImpl<MCFixup> &Fixups) const {
437 // Convert a list of GPRs into a bitfield (R0 -> bit 0). For each
438 // register in the list, set the corresponding bit.
440 for (unsigned i = Op, e = MI.getNumOperands(); i < e; ++i) {
441 unsigned regno = getARMRegisterNumbering(MI.getOperand(i).getReg());
442 Binary |= 1 << regno;
447 unsigned ARMMCCodeEmitter::
448 getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
449 SmallVectorImpl<MCFixup> &Fixups) const {
450 const MCOperand &Reg = MI.getOperand(Op);
451 const MCOperand &Imm = MI.getOperand(Op + 1);
453 unsigned RegNo = getARMRegisterNumbering(Reg.getReg());
456 switch (Imm.getImm()) {
460 case 8: Align = 0x01; break;
461 case 16: Align = 0x02; break;
462 case 32: Align = 0x03; break;
465 return RegNo | (Align << 4);
468 unsigned ARMMCCodeEmitter::
469 getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
470 SmallVectorImpl<MCFixup> &Fixups) const {
471 const MCOperand &MO = MI.getOperand(Op);
472 if (MO.getReg() == 0) return 0x0D;
476 void ARMMCCodeEmitter::
477 EncodeInstruction(const MCInst &MI, raw_ostream &OS,
478 SmallVectorImpl<MCFixup> &Fixups) const {
479 // Pseudo instructions don't get encoded.
480 const TargetInstrDesc &Desc = TII.get(MI.getOpcode());
481 if ((Desc.TSFlags & ARMII::FormMask) == ARMII::Pseudo)
484 EmitConstant(getBinaryCodeForInstr(MI, Fixups), 4, OS);
485 ++MCNumEmitted; // Keep track of the # of mi's emitted.
488 #include "ARMGenMCCodeEmitter.inc"