1//===-- ARM/ARMMCCodeEmitter.cpp - Convert ARM code to machine code -------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the ARMMCCodeEmitter class.
11//
12//===----------------------------------------------------------------------===//
13
14#define DEBUG_TYPE "mccodeemitter"
15#include "MCTargetDesc/ARMAddressingModes.h"
16#include "MCTargetDesc/ARMBaseInfo.h"
17#include "MCTargetDesc/ARMFixupKinds.h"
18#include "MCTargetDesc/ARMMCExpr.h"
19#include "MCTargetDesc/ARMMCTargetDesc.h"
20#include "llvm/MC/MCCodeEmitter.h"
21#include "llvm/MC/MCContext.h"
22#include "llvm/MC/MCExpr.h"
23#include "llvm/MC/MCInst.h"
24#include "llvm/MC/MCInstrInfo.h"
25#include "llvm/MC/MCRegisterInfo.h"
26#include "llvm/MC/MCSubtargetInfo.h"
27#include "llvm/ADT/APFloat.h"
28#include "llvm/ADT/Statistic.h"
29#include "llvm/Support/raw_ostream.h"
30
31using namespace llvm;
32
33STATISTIC(MCNumEmitted, "Number of MC instructions emitted.");
34STATISTIC(MCNumCPRelocations, "Number of constant pool relocations created.");
35
36namespace {
37class ARMMCCodeEmitter : public MCCodeEmitter {
38  ARMMCCodeEmitter(const ARMMCCodeEmitter &) LLVM_DELETED_FUNCTION;
39  void operator=(const ARMMCCodeEmitter &) LLVM_DELETED_FUNCTION;
40  const MCInstrInfo &MCII;
41  const MCSubtargetInfo &STI;
42  const MCContext &CTX;
43
44public:
45  ARMMCCodeEmitter(const MCInstrInfo &mcii, const MCSubtargetInfo &sti,
46                   MCContext &ctx)
47    : MCII(mcii), STI(sti), CTX(ctx) {
48  }
49
50  ~ARMMCCodeEmitter() {}
51
52  bool isThumb() const {
53    // FIXME: Can tablegen auto-generate this?
54    return (STI.getFeatureBits() & ARM::ModeThumb) != 0;
55  }
56  bool isThumb2() const {
57    return isThumb() && (STI.getFeatureBits() & ARM::FeatureThumb2) != 0;
58  }
59  bool isTargetDarwin() const {
60    Triple TT(STI.getTargetTriple());
61    Triple::OSType OS = TT.getOS();
62    return OS == Triple::Darwin || OS == Triple::MacOSX || OS == Triple::IOS;
63  }
64
65  unsigned getMachineSoImmOpValue(unsigned SoImm) const;
66
67  // getBinaryCodeForInstr - TableGen'erated function for getting the
68  // binary encoding for an instruction.
69  uint64_t getBinaryCodeForInstr(const MCInst &MI,
70                                 SmallVectorImpl<MCFixup> &Fixups) const;
71
72  /// getMachineOpValue - Return binary encoding of operand. If the machine
73  /// operand requires relocation, record the relocation and return zero.
74  unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
75                             SmallVectorImpl<MCFixup> &Fixups) const;
76
77  /// getHiLo16ImmOpValue - Return the encoding for the hi / low 16-bit of
78  /// the specified operand. This is used for operands with :lower16: and
79  /// :upper16: prefixes.
80  uint32_t getHiLo16ImmOpValue(const MCInst &MI, unsigned OpIdx,
81                               SmallVectorImpl<MCFixup> &Fixups) const;
82
83  bool EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx,
84                              unsigned &Reg, unsigned &Imm,
85                              SmallVectorImpl<MCFixup> &Fixups) const;
86
87  /// getThumbBLTargetOpValue - Return encoding info for Thumb immediate
88  /// BL branch target.
89  uint32_t getThumbBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
90                                   SmallVectorImpl<MCFixup> &Fixups) const;
91
92  /// getThumbBLXTargetOpValue - Return encoding info for Thumb immediate
93  /// BLX branch target.
94  uint32_t getThumbBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
95                                    SmallVectorImpl<MCFixup> &Fixups) const;
96
97  /// getThumbBRTargetOpValue - Return encoding info for Thumb branch target.
98  uint32_t getThumbBRTargetOpValue(const MCInst &MI, unsigned OpIdx,
99                                   SmallVectorImpl<MCFixup> &Fixups) const;
100
101  /// getThumbBCCTargetOpValue - Return encoding info for Thumb branch target.
102  uint32_t getThumbBCCTargetOpValue(const MCInst &MI, unsigned OpIdx,
103                                    SmallVectorImpl<MCFixup> &Fixups) const;
104
105  /// getThumbCBTargetOpValue - Return encoding info for Thumb branch target.
106  uint32_t getThumbCBTargetOpValue(const MCInst &MI, unsigned OpIdx,
107                                   SmallVectorImpl<MCFixup> &Fixups) const;
108
109  /// getBranchTargetOpValue - Return encoding info for 24-bit immediate
110  /// branch target.
111  uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
112                                  SmallVectorImpl<MCFixup> &Fixups) const;
113
114  /// getUnconditionalBranchTargetOpValue - Return encoding info for 24-bit
115  /// immediate Thumb2 direct branch target.
116  uint32_t getUnconditionalBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
117                                  SmallVectorImpl<MCFixup> &Fixups) const;
118
119  /// getARMBranchTargetOpValue - Return encoding info for 24-bit immediate
120  /// branch target.
121  uint32_t getARMBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
122                                     SmallVectorImpl<MCFixup> &Fixups) const;
123  uint32_t getARMBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
124                                 SmallVectorImpl<MCFixup> &Fixups) const;
125  uint32_t getARMBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
126                                  SmallVectorImpl<MCFixup> &Fixups) const;
127
128  /// getAdrLabelOpValue - Return encoding info for 12-bit immediate
129  /// ADR label target.
130  uint32_t getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
131                              SmallVectorImpl<MCFixup> &Fixups) const;
132  uint32_t getThumbAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
133                              SmallVectorImpl<MCFixup> &Fixups) const;
134  uint32_t getT2AdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
135                              SmallVectorImpl<MCFixup> &Fixups) const;
136
137
138  /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12'
139  /// operand.
140  uint32_t getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
141                                   SmallVectorImpl<MCFixup> &Fixups) const;
142
143  /// getThumbAddrModeRegRegOpValue - Return encoding for 'reg + reg' operand.
144  uint32_t getThumbAddrModeRegRegOpValue(const MCInst &MI, unsigned OpIdx,
145                                         SmallVectorImpl<MCFixup> &Fixups)const;
146
147  /// getT2AddrModeImm8s4OpValue - Return encoding info for 'reg +/- imm8<<2'
148  /// operand.
149  uint32_t getT2AddrModeImm8s4OpValue(const MCInst &MI, unsigned OpIdx,
150                                   SmallVectorImpl<MCFixup> &Fixups) const;
151
152  /// getT2AddrModeImm0_1020s4OpValue - Return encoding info for 'reg + imm8<<2'
153  /// operand.
154  uint32_t getT2AddrModeImm0_1020s4OpValue(const MCInst &MI, unsigned OpIdx,
155                                   SmallVectorImpl<MCFixup> &Fixups) const;
156
157  /// getT2Imm8s4OpValue - Return encoding info for '+/- imm8<<2'
158  /// operand.
159  uint32_t getT2Imm8s4OpValue(const MCInst &MI, unsigned OpIdx,
160                              SmallVectorImpl<MCFixup> &Fixups) const;
161
162
163  /// getLdStSORegOpValue - Return encoding info for 'reg +/- reg shop imm'
164  /// operand as needed by load/store instructions.
165  uint32_t getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
166                               SmallVectorImpl<MCFixup> &Fixups) const;
167
168  /// getLdStmModeOpValue - Return encoding for load/store multiple mode.
169  uint32_t getLdStmModeOpValue(const MCInst &MI, unsigned OpIdx,
170                               SmallVectorImpl<MCFixup> &Fixups) const {
171    ARM_AM::AMSubMode Mode = (ARM_AM::AMSubMode)MI.getOperand(OpIdx).getImm();
172    switch (Mode) {
173    default: llvm_unreachable("Unknown addressing sub-mode!");
174    case ARM_AM::da: return 0;
175    case ARM_AM::ia: return 1;
176    case ARM_AM::db: return 2;
177    case ARM_AM::ib: return 3;
178    }
179  }
180  /// getShiftOp - Return the shift opcode (bit[6:5]) of the immediate value.
181  ///
182  unsigned getShiftOp(ARM_AM::ShiftOpc ShOpc) const {
183    switch (ShOpc) {
184    case ARM_AM::no_shift:
185    case ARM_AM::lsl: return 0;
186    case ARM_AM::lsr: return 1;
187    case ARM_AM::asr: return 2;
188    case ARM_AM::ror:
189    case ARM_AM::rrx: return 3;
190    }
191    llvm_unreachable("Invalid ShiftOpc!");
192  }
193
194  /// getAddrMode2OpValue - Return encoding for addrmode2 operands.
195  uint32_t getAddrMode2OpValue(const MCInst &MI, unsigned OpIdx,
196                               SmallVectorImpl<MCFixup> &Fixups) const;
197
198  /// getAddrMode2OffsetOpValue - Return encoding for am2offset operands.
199  uint32_t getAddrMode2OffsetOpValue(const MCInst &MI, unsigned OpIdx,
200                                     SmallVectorImpl<MCFixup> &Fixups) const;
201
202  /// getPostIdxRegOpValue - Return encoding for postidx_reg operands.
203  uint32_t getPostIdxRegOpValue(const MCInst &MI, unsigned OpIdx,
204                                SmallVectorImpl<MCFixup> &Fixups) const;
205
206  /// getAddrMode3OffsetOpValue - Return encoding for am3offset operands.
207  uint32_t getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
208                                     SmallVectorImpl<MCFixup> &Fixups) const;
209
210  /// getAddrMode3OpValue - Return encoding for addrmode3 operands.
211  uint32_t getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
212                               SmallVectorImpl<MCFixup> &Fixups) const;
213
214  /// getAddrModeThumbSPOpValue - Return encoding info for 'reg +/- imm12'
215  /// operand.
216  uint32_t getAddrModeThumbSPOpValue(const MCInst &MI, unsigned OpIdx,
217                                     SmallVectorImpl<MCFixup> &Fixups) const;
218
219  /// getAddrModeISOpValue - Encode the t_addrmode_is# operands.
220  uint32_t getAddrModeISOpValue(const MCInst &MI, unsigned OpIdx,
221                                SmallVectorImpl<MCFixup> &Fixups) const;
222
223  /// getAddrModePCOpValue - Return encoding for t_addrmode_pc operands.
224  uint32_t getAddrModePCOpValue(const MCInst &MI, unsigned OpIdx,
225                                SmallVectorImpl<MCFixup> &Fixups) const;
226
227  /// getAddrMode5OpValue - Return encoding info for 'reg +/- imm8' operand.
228  uint32_t getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
229                               SmallVectorImpl<MCFixup> &Fixups) const;
230
231  /// getCCOutOpValue - Return encoding of the 's' bit.
232  unsigned getCCOutOpValue(const MCInst &MI, unsigned Op,
233                           SmallVectorImpl<MCFixup> &Fixups) const {
234    // The operand is either reg0 or CPSR. The 's' bit is encoded as '0' or
235    // '1' respectively.
236    return MI.getOperand(Op).getReg() == ARM::CPSR;
237  }
238
239  /// getSOImmOpValue - Return an encoded 12-bit shifted-immediate value.
240  unsigned getSOImmOpValue(const MCInst &MI, unsigned Op,
241                           SmallVectorImpl<MCFixup> &Fixups) const {
242    unsigned SoImm = MI.getOperand(Op).getImm();
243    int SoImmVal = ARM_AM::getSOImmVal(SoImm);
244    assert(SoImmVal != -1 && "Not a valid so_imm value!");
245
246    // Encode rotate_imm.
247    unsigned Binary = (ARM_AM::getSOImmValRot((unsigned)SoImmVal) >> 1)
248      << ARMII::SoRotImmShift;
249
250    // Encode immed_8.
251    Binary |= ARM_AM::getSOImmValImm((unsigned)SoImmVal);
252    return Binary;
253  }
254
255  /// getT2SOImmOpValue - Return an encoded 12-bit shifted-immediate value.
256  unsigned getT2SOImmOpValue(const MCInst &MI, unsigned Op,
257                           SmallVectorImpl<MCFixup> &Fixups) const {
258    unsigned SoImm = MI.getOperand(Op).getImm();
259    unsigned Encoded =  ARM_AM::getT2SOImmVal(SoImm);
260    assert(Encoded != ~0U && "Not a Thumb2 so_imm value?");
261    return Encoded;
262  }
263
264  unsigned getT2AddrModeSORegOpValue(const MCInst &MI, unsigned OpNum,
265    SmallVectorImpl<MCFixup> &Fixups) const;
266  unsigned getT2AddrModeImm8OpValue(const MCInst &MI, unsigned OpNum,
267    SmallVectorImpl<MCFixup> &Fixups) const;
268  unsigned getT2AddrModeImm8OffsetOpValue(const MCInst &MI, unsigned OpNum,
269    SmallVectorImpl<MCFixup> &Fixups) const;
270  unsigned getT2AddrModeImm12OffsetOpValue(const MCInst &MI, unsigned OpNum,
271    SmallVectorImpl<MCFixup> &Fixups) const;
272
273  /// getSORegOpValue - Return an encoded so_reg shifted register value.
274  unsigned getSORegRegOpValue(const MCInst &MI, unsigned Op,
275                           SmallVectorImpl<MCFixup> &Fixups) const;
276  unsigned getSORegImmOpValue(const MCInst &MI, unsigned Op,
277                           SmallVectorImpl<MCFixup> &Fixups) const;
278  unsigned getT2SORegOpValue(const MCInst &MI, unsigned Op,
279                             SmallVectorImpl<MCFixup> &Fixups) const;
280
281  unsigned getNEONVcvtImm32OpValue(const MCInst &MI, unsigned Op,
282                                   SmallVectorImpl<MCFixup> &Fixups) const {
283    return 64 - MI.getOperand(Op).getImm();
284  }
285
286  unsigned getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
287                                      SmallVectorImpl<MCFixup> &Fixups) const;
288
289  unsigned getRegisterListOpValue(const MCInst &MI, unsigned Op,
290                                  SmallVectorImpl<MCFixup> &Fixups) const;
291  unsigned getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
292                                      SmallVectorImpl<MCFixup> &Fixups) const;
293  unsigned getAddrMode6OneLane32AddressOpValue(const MCInst &MI, unsigned Op,
294                                        SmallVectorImpl<MCFixup> &Fixups) const;
295  unsigned getAddrMode6DupAddressOpValue(const MCInst &MI, unsigned Op,
296                                        SmallVectorImpl<MCFixup> &Fixups) const;
297  unsigned getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
298                                     SmallVectorImpl<MCFixup> &Fixups) const;
299
300  unsigned getShiftRight8Imm(const MCInst &MI, unsigned Op,
301                             SmallVectorImpl<MCFixup> &Fixups) const;
302  unsigned getShiftRight16Imm(const MCInst &MI, unsigned Op,
303                              SmallVectorImpl<MCFixup> &Fixups) const;
304  unsigned getShiftRight32Imm(const MCInst &MI, unsigned Op,
305                              SmallVectorImpl<MCFixup> &Fixups) const;
306  unsigned getShiftRight64Imm(const MCInst &MI, unsigned Op,
307                              SmallVectorImpl<MCFixup> &Fixups) const;
308
309  unsigned getThumbSRImmOpValue(const MCInst &MI, unsigned Op,
310                                 SmallVectorImpl<MCFixup> &Fixups) const;
311
312  unsigned NEONThumb2DataIPostEncoder(const MCInst &MI,
313                                      unsigned EncodedValue) const;
314  unsigned NEONThumb2LoadStorePostEncoder(const MCInst &MI,
315                                          unsigned EncodedValue) const;
316  unsigned NEONThumb2DupPostEncoder(const MCInst &MI,
317                                    unsigned EncodedValue) const;
318
319  unsigned VFPThumb2PostEncoder(const MCInst &MI,
320                                unsigned EncodedValue) const;
321
322  void EmitByte(unsigned char C, raw_ostream &OS) const {
323    OS << (char)C;
324  }
325
326  void EmitConstant(uint64_t Val, unsigned Size, raw_ostream &OS) const {
327    // Output the constant in little endian byte order.
328    for (unsigned i = 0; i != Size; ++i) {
329      EmitByte(Val & 255, OS);
330      Val >>= 8;
331    }
332  }
333
334  void EncodeInstruction(const MCInst &MI, raw_ostream &OS,
335                         SmallVectorImpl<MCFixup> &Fixups) const;
336};
337
338} // end anonymous namespace
339
340MCCodeEmitter *llvm::createARMMCCodeEmitter(const MCInstrInfo &MCII,
341                                            const MCRegisterInfo &MRI,
342                                            const MCSubtargetInfo &STI,
343                                            MCContext &Ctx) {
344  return new ARMMCCodeEmitter(MCII, STI, Ctx);
345}
346
347/// NEONThumb2DataIPostEncoder - Post-process encoded NEON data-processing
348/// instructions, and rewrite them to their Thumb2 form if we are currently in
349/// Thumb2 mode.
350unsigned ARMMCCodeEmitter::NEONThumb2DataIPostEncoder(const MCInst &MI,
351                                                 unsigned EncodedValue) const {
352  if (isThumb2()) {
353    // NEON Thumb2 data-processsing encodings are very simple: bit 24 is moved
354    // to bit 12 of the high half-word (i.e. bit 28), and bits 27-24 are
355    // set to 1111.
356    unsigned Bit24 = EncodedValue & 0x01000000;
357    unsigned Bit28 = Bit24 << 4;
358    EncodedValue &= 0xEFFFFFFF;
359    EncodedValue |= Bit28;
360    EncodedValue |= 0x0F000000;
361  }
362
363  return EncodedValue;
364}
365
366/// NEONThumb2LoadStorePostEncoder - Post-process encoded NEON load/store
367/// instructions, and rewrite them to their Thumb2 form if we are currently in
368/// Thumb2 mode.
369unsigned ARMMCCodeEmitter::NEONThumb2LoadStorePostEncoder(const MCInst &MI,
370                                                 unsigned EncodedValue) const {
371  if (isThumb2()) {
372    EncodedValue &= 0xF0FFFFFF;
373    EncodedValue |= 0x09000000;
374  }
375
376  return EncodedValue;
377}
378
379/// NEONThumb2DupPostEncoder - Post-process encoded NEON vdup
380/// instructions, and rewrite them to their Thumb2 form if we are currently in
381/// Thumb2 mode.
382unsigned ARMMCCodeEmitter::NEONThumb2DupPostEncoder(const MCInst &MI,
383                                                 unsigned EncodedValue) const {
384  if (isThumb2()) {
385    EncodedValue &= 0x00FFFFFF;
386    EncodedValue |= 0xEE000000;
387  }
388
389  return EncodedValue;
390}
391
392/// VFPThumb2PostEncoder - Post-process encoded VFP instructions and rewrite
393/// them to their Thumb2 form if we are currently in Thumb2 mode.
394unsigned ARMMCCodeEmitter::
395VFPThumb2PostEncoder(const MCInst &MI, unsigned EncodedValue) const {
396  if (isThumb2()) {
397    EncodedValue &= 0x0FFFFFFF;
398    EncodedValue |= 0xE0000000;
399  }
400  return EncodedValue;
401}
402
403/// getMachineOpValue - Return binary encoding of operand. If the machine
404/// operand requires relocation, record the relocation and return zero.
405unsigned ARMMCCodeEmitter::
406getMachineOpValue(const MCInst &MI, const MCOperand &MO,
407                  SmallVectorImpl<MCFixup> &Fixups) const {
408  if (MO.isReg()) {
409    unsigned Reg = MO.getReg();
410    unsigned RegNo = CTX.getRegisterInfo().getEncodingValue(Reg);
411
412    // Q registers are encoded as 2x their register number.
413    switch (Reg) {
414    default:
415      return RegNo;
416    case ARM::Q0:  case ARM::Q1:  case ARM::Q2:  case ARM::Q3:
417    case ARM::Q4:  case ARM::Q5:  case ARM::Q6:  case ARM::Q7:
418    case ARM::Q8:  case ARM::Q9:  case ARM::Q10: case ARM::Q11:
419    case ARM::Q12: case ARM::Q13: case ARM::Q14: case ARM::Q15:
420      return 2 * RegNo;
421    }
422  } else if (MO.isImm()) {
423    return static_cast<unsigned>(MO.getImm());
424  } else if (MO.isFPImm()) {
425    return static_cast<unsigned>(APFloat(MO.getFPImm())
426                     .bitcastToAPInt().getHiBits(32).getLimitedValue());
427  }
428
429  llvm_unreachable("Unable to encode MCOperand!");
430}
431
432/// getAddrModeImmOpValue - Return encoding info for 'reg +/- imm' operand.
433bool ARMMCCodeEmitter::
434EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx, unsigned &Reg,
435                       unsigned &Imm, SmallVectorImpl<MCFixup> &Fixups) const {
436  const MCOperand &MO  = MI.getOperand(OpIdx);
437  const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
438
439  Reg = CTX.getRegisterInfo().getEncodingValue(MO.getReg());
440
441  int32_t SImm = MO1.getImm();
442  bool isAdd = true;
443
444  // Special value for #-0
445  if (SImm == INT32_MIN) {
446    SImm = 0;
447    isAdd = false;
448  }
449
450  // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
451  if (SImm < 0) {
452    SImm = -SImm;
453    isAdd = false;
454  }
455
456  Imm = SImm;
457  return isAdd;
458}
459
460/// getBranchTargetOpValue - Helper function to get the branch target operand,
461/// which is either an immediate or requires a fixup.
462static uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
463                                       unsigned FixupKind,
464                                       SmallVectorImpl<MCFixup> &Fixups) {
465  const MCOperand &MO = MI.getOperand(OpIdx);
466
467  // If the destination is an immediate, we have nothing to do.
468  if (MO.isImm()) return MO.getImm();
469  assert(MO.isExpr() && "Unexpected branch target type!");
470  const MCExpr *Expr = MO.getExpr();
471  MCFixupKind Kind = MCFixupKind(FixupKind);
472  Fixups.push_back(MCFixup::Create(0, Expr, Kind, MI.getLoc()));
473
474  // All of the information is in the fixup.
475  return 0;
476}
477
478// Thumb BL and BLX use a strange offset encoding where bits 22 and 21 are
479// determined by negating them and XOR'ing them with bit 23.
480static int32_t encodeThumbBLOffset(int32_t offset) {
481  offset >>= 1;
482  uint32_t S  = (offset & 0x800000) >> 23;
483  uint32_t J1 = (offset & 0x400000) >> 22;
484  uint32_t J2 = (offset & 0x200000) >> 21;
485  J1 = (~J1 & 0x1);
486  J2 = (~J2 & 0x1);
487  J1 ^= S;
488  J2 ^= S;
489
490  offset &= ~0x600000;
491  offset |= J1 << 22;
492  offset |= J2 << 21;
493
494  return offset;
495}
496
497/// getThumbBLTargetOpValue - Return encoding info for immediate branch target.
498uint32_t ARMMCCodeEmitter::
499getThumbBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
500                        SmallVectorImpl<MCFixup> &Fixups) const {
501  const MCOperand MO = MI.getOperand(OpIdx);
502  if (MO.isExpr())
503    return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_bl,
504                                    Fixups);
505  return encodeThumbBLOffset(MO.getImm());
506}
507
508/// getThumbBLXTargetOpValue - Return encoding info for Thumb immediate
509/// BLX branch target.
510uint32_t ARMMCCodeEmitter::
511getThumbBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
512                         SmallVectorImpl<MCFixup> &Fixups) const {
513  const MCOperand MO = MI.getOperand(OpIdx);
514  if (MO.isExpr())
515    return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_blx,
516                                    Fixups);
517  return encodeThumbBLOffset(MO.getImm());
518}
519
520/// getThumbBRTargetOpValue - Return encoding info for Thumb branch target.
521uint32_t ARMMCCodeEmitter::
522getThumbBRTargetOpValue(const MCInst &MI, unsigned OpIdx,
523                        SmallVectorImpl<MCFixup> &Fixups) const {
524  const MCOperand MO = MI.getOperand(OpIdx);
525  if (MO.isExpr())
526    return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_br,
527                                    Fixups);
528  return (MO.getImm() >> 1);
529}
530
531/// getThumbBCCTargetOpValue - Return encoding info for Thumb branch target.
532uint32_t ARMMCCodeEmitter::
533getThumbBCCTargetOpValue(const MCInst &MI, unsigned OpIdx,
534                         SmallVectorImpl<MCFixup> &Fixups) const {
535  const MCOperand MO = MI.getOperand(OpIdx);
536  if (MO.isExpr())
537    return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_bcc,
538                                    Fixups);
539  return (MO.getImm() >> 1);
540}
541
542/// getThumbCBTargetOpValue - Return encoding info for Thumb branch target.
543uint32_t ARMMCCodeEmitter::
544getThumbCBTargetOpValue(const MCInst &MI, unsigned OpIdx,
545                        SmallVectorImpl<MCFixup> &Fixups) const {
546  const MCOperand MO = MI.getOperand(OpIdx);
547  if (MO.isExpr())
548    return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_cb, Fixups);
549  return (MO.getImm() >> 1);
550}
551
552/// Return true if this branch has a non-always predication
553static bool HasConditionalBranch(const MCInst &MI) {
554  int NumOp = MI.getNumOperands();
555  if (NumOp >= 2) {
556    for (int i = 0; i < NumOp-1; ++i) {
557      const MCOperand &MCOp1 = MI.getOperand(i);
558      const MCOperand &MCOp2 = MI.getOperand(i + 1);
559      if (MCOp1.isImm() && MCOp2.isReg() &&
560          (MCOp2.getReg() == 0 || MCOp2.getReg() == ARM::CPSR)) {
561        if (ARMCC::CondCodes(MCOp1.getImm()) != ARMCC::AL)
562          return true;
563      }
564    }
565  }
566  return false;
567}
568
569/// getBranchTargetOpValue - Return encoding info for 24-bit immediate branch
570/// target.
571uint32_t ARMMCCodeEmitter::
572getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
573                       SmallVectorImpl<MCFixup> &Fixups) const {
574  // FIXME: This really, really shouldn't use TargetMachine. We don't want
575  // coupling between MC and TM anywhere we can help it.
576  if (isThumb2())
577    return
578      ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_condbranch, Fixups);
579  return getARMBranchTargetOpValue(MI, OpIdx, Fixups);
580}
581
582/// getBranchTargetOpValue - Return encoding info for 24-bit immediate branch
583/// target.
584uint32_t ARMMCCodeEmitter::
585getARMBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
586                          SmallVectorImpl<MCFixup> &Fixups) const {
587  const MCOperand MO = MI.getOperand(OpIdx);
588  if (MO.isExpr()) {
589    if (HasConditionalBranch(MI))
590      return ::getBranchTargetOpValue(MI, OpIdx,
591                                      ARM::fixup_arm_condbranch, Fixups);
592    return ::getBranchTargetOpValue(MI, OpIdx,
593                                    ARM::fixup_arm_uncondbranch, Fixups);
594  }
595
596  return MO.getImm() >> 2;
597}
598
599uint32_t ARMMCCodeEmitter::
600getARMBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
601                          SmallVectorImpl<MCFixup> &Fixups) const {
602  const MCOperand MO = MI.getOperand(OpIdx);
603  if (MO.isExpr()) {
604    if (HasConditionalBranch(MI))
605      return ::getBranchTargetOpValue(MI, OpIdx,
606                                      ARM::fixup_arm_condbl, Fixups);
607    return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_uncondbl, Fixups);
608  }
609
610  return MO.getImm() >> 2;
611}
612
613uint32_t ARMMCCodeEmitter::
614getARMBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
615                          SmallVectorImpl<MCFixup> &Fixups) const {
616  const MCOperand MO = MI.getOperand(OpIdx);
617  if (MO.isExpr())
618    return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_blx, Fixups);
619
620  return MO.getImm() >> 1;
621}
622
623/// getUnconditionalBranchTargetOpValue - Return encoding info for 24-bit
624/// immediate branch target.
625uint32_t ARMMCCodeEmitter::
626getUnconditionalBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
627                       SmallVectorImpl<MCFixup> &Fixups) const {
628  unsigned Val =
629    ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_uncondbranch, Fixups);
630  bool I  = (Val & 0x800000);
631  bool J1 = (Val & 0x400000);
632  bool J2 = (Val & 0x200000);
633  if (I ^ J1)
634    Val &= ~0x400000;
635  else
636    Val |= 0x400000;
637
638  if (I ^ J2)
639    Val &= ~0x200000;
640  else
641    Val |= 0x200000;
642
643  return Val;
644}
645
646/// getAdrLabelOpValue - Return encoding info for 12-bit shifted-immediate
647/// ADR label target.
648uint32_t ARMMCCodeEmitter::
649getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
650                   SmallVectorImpl<MCFixup> &Fixups) const {
651  const MCOperand MO = MI.getOperand(OpIdx);
652  if (MO.isExpr())
653    return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_adr_pcrel_12,
654                                    Fixups);
655  int32_t offset = MO.getImm();
656  uint32_t Val = 0x2000;
657
658  if (offset == INT32_MIN) {
659    Val = 0x1000;
660    offset = 0;
661  } else if (offset < 0) {
662    Val = 0x1000;
663    offset *= -1;
664  }
665
666  int SoImmVal = ARM_AM::getSOImmVal(offset);
667  assert(SoImmVal != -1 && "Not a valid so_imm value!");
668
669  Val |= SoImmVal;
670  return Val;
671}
672
673/// getT2AdrLabelOpValue - Return encoding info for 12-bit immediate ADR label
674/// target.
675uint32_t ARMMCCodeEmitter::
676getT2AdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
677                   SmallVectorImpl<MCFixup> &Fixups) const {
678  const MCOperand MO = MI.getOperand(OpIdx);
679  if (MO.isExpr())
680    return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_adr_pcrel_12,
681                                    Fixups);
682  int32_t Val = MO.getImm();
683  if (Val == INT32_MIN)
684    Val = 0x1000;
685  else if (Val < 0) {
686    Val *= -1;
687    Val |= 0x1000;
688  }
689  return Val;
690}
691
692/// getThumbAdrLabelOpValue - Return encoding info for 8-bit immediate ADR label
693/// target.
694uint32_t ARMMCCodeEmitter::
695getThumbAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
696                   SmallVectorImpl<MCFixup> &Fixups) const {
697  const MCOperand MO = MI.getOperand(OpIdx);
698  if (MO.isExpr())
699    return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_thumb_adr_pcrel_10,
700                                    Fixups);
701  return MO.getImm();
702}
703
704/// getThumbAddrModeRegRegOpValue - Return encoding info for 'reg + reg'
705/// operand.
706uint32_t ARMMCCodeEmitter::
707getThumbAddrModeRegRegOpValue(const MCInst &MI, unsigned OpIdx,
708                              SmallVectorImpl<MCFixup> &) const {
709  // [Rn, Rm]
710  //   {5-3} = Rm
711  //   {2-0} = Rn
712  const MCOperand &MO1 = MI.getOperand(OpIdx);
713  const MCOperand &MO2 = MI.getOperand(OpIdx + 1);
714  unsigned Rn = CTX.getRegisterInfo().getEncodingValue(MO1.getReg());
715  unsigned Rm = CTX.getRegisterInfo().getEncodingValue(MO2.getReg());
716  return (Rm << 3) | Rn;
717}
718
719/// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12' operand.
720uint32_t ARMMCCodeEmitter::
721getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
722                        SmallVectorImpl<MCFixup> &Fixups) const {
723  // {17-13} = reg
724  // {12}    = (U)nsigned (add == '1', sub == '0')
725  // {11-0}  = imm12
726  unsigned Reg, Imm12;
727  bool isAdd = true;
728  // If The first operand isn't a register, we have a label reference.
729  const MCOperand &MO = MI.getOperand(OpIdx);
730  if (!MO.isReg()) {
731    Reg = CTX.getRegisterInfo().getEncodingValue(ARM::PC);   // Rn is PC.
732    Imm12 = 0;
733    isAdd = false ; // 'U' bit is set as part of the fixup.
734
735    if (MO.isExpr()) {
736      const MCExpr *Expr = MO.getExpr();
737
738      MCFixupKind Kind;
739      if (isThumb2())
740        Kind = MCFixupKind(ARM::fixup_t2_ldst_pcrel_12);
741      else
742        Kind = MCFixupKind(ARM::fixup_arm_ldst_pcrel_12);
743      Fixups.push_back(MCFixup::Create(0, Expr, Kind, MI.getLoc()));
744
745      ++MCNumCPRelocations;
746    } else {
747      Reg = ARM::PC;
748      int32_t Offset = MO.getImm();
749      // FIXME: Handle #-0.
750      if (Offset < 0) {
751        Offset *= -1;
752        isAdd = false;
753      }
754      Imm12 = Offset;
755    }
756  } else
757    isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm12, Fixups);
758
759  uint32_t Binary = Imm12 & 0xfff;
760  // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
761  if (isAdd)
762    Binary |= (1 << 12);
763  Binary |= (Reg << 13);
764  return Binary;
765}
766
767/// getT2Imm8s4OpValue - Return encoding info for
768/// '+/- imm8<<2' operand.
769uint32_t ARMMCCodeEmitter::
770getT2Imm8s4OpValue(const MCInst &MI, unsigned OpIdx,
771                   SmallVectorImpl<MCFixup> &Fixups) const {
772  // FIXME: The immediate operand should have already been encoded like this
773  // before ever getting here. The encoder method should just need to combine
774  // the MI operands for the register and the offset into a single
775  // representation for the complex operand in the .td file. This isn't just
776  // style, unfortunately. As-is, we can't represent the distinct encoding
777  // for #-0.
778
779  // {8}    = (U)nsigned (add == '1', sub == '0')
780  // {7-0}  = imm8
781  int32_t Imm8 = MI.getOperand(OpIdx).getImm();
782  bool isAdd = Imm8 >= 0;
783
784  // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
785  if (Imm8 < 0)
786    Imm8 = -(uint32_t)Imm8;
787
788  // Scaled by 4.
789  Imm8 /= 4;
790
791  uint32_t Binary = Imm8 & 0xff;
792  // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
793  if (isAdd)
794    Binary |= (1 << 8);
795  return Binary;
796}
797
798/// getT2AddrModeImm8s4OpValue - Return encoding info for
799/// 'reg +/- imm8<<2' operand.
800uint32_t ARMMCCodeEmitter::
801getT2AddrModeImm8s4OpValue(const MCInst &MI, unsigned OpIdx,
802                        SmallVectorImpl<MCFixup> &Fixups) const {
803  // {12-9} = reg
804  // {8}    = (U)nsigned (add == '1', sub == '0')
805  // {7-0}  = imm8
806  unsigned Reg, Imm8;
807  bool isAdd = true;
808  // If The first operand isn't a register, we have a label reference.
809  const MCOperand &MO = MI.getOperand(OpIdx);
810  if (!MO.isReg()) {
811    Reg = CTX.getRegisterInfo().getEncodingValue(ARM::PC);   // Rn is PC.
812    Imm8 = 0;
813    isAdd = false ; // 'U' bit is set as part of the fixup.
814
815    assert(MO.isExpr() && "Unexpected machine operand type!");
816    const MCExpr *Expr = MO.getExpr();
817    MCFixupKind Kind = MCFixupKind(ARM::fixup_t2_pcrel_10);
818    Fixups.push_back(MCFixup::Create(0, Expr, Kind, MI.getLoc()));
819
820    ++MCNumCPRelocations;
821  } else
822    isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups);
823
824  // FIXME: The immediate operand should have already been encoded like this
825  // before ever getting here. The encoder method should just need to combine
826  // the MI operands for the register and the offset into a single
827  // representation for the complex operand in the .td file. This isn't just
828  // style, unfortunately. As-is, we can't represent the distinct encoding
829  // for #-0.
830  uint32_t Binary = (Imm8 >> 2) & 0xff;
831  // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
832  if (isAdd)
833    Binary |= (1 << 8);
834  Binary |= (Reg << 9);
835  return Binary;
836}
837
838/// getT2AddrModeImm0_1020s4OpValue - Return encoding info for
839/// 'reg + imm8<<2' operand.
840uint32_t ARMMCCodeEmitter::
841getT2AddrModeImm0_1020s4OpValue(const MCInst &MI, unsigned OpIdx,
842                        SmallVectorImpl<MCFixup> &Fixups) const {
843  // {11-8} = reg
844  // {7-0}  = imm8
845  const MCOperand &MO = MI.getOperand(OpIdx);
846  const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
847  unsigned Reg = CTX.getRegisterInfo().getEncodingValue(MO.getReg());
848  unsigned Imm8 = MO1.getImm();
849  return (Reg << 8) | Imm8;
850}
851
852// FIXME: This routine assumes that a binary
853// expression will always result in a PCRel expression
854// In reality, its only true if one or more subexpressions
855// is itself a PCRel (i.e. "." in asm or some other pcrel construct)
856// but this is good enough for now.
857static bool EvaluateAsPCRel(const MCExpr *Expr) {
858  switch (Expr->getKind()) {
859  default: llvm_unreachable("Unexpected expression type");
860  case MCExpr::SymbolRef: return false;
861  case MCExpr::Binary: return true;
862  }
863}
864
865uint32_t
866ARMMCCodeEmitter::getHiLo16ImmOpValue(const MCInst &MI, unsigned OpIdx,
867                                      SmallVectorImpl<MCFixup> &Fixups) const {
868  // {20-16} = imm{15-12}
869  // {11-0}  = imm{11-0}
870  const MCOperand &MO = MI.getOperand(OpIdx);
871  if (MO.isImm())
872    // Hi / lo 16 bits already extracted during earlier passes.
873    return static_cast<unsigned>(MO.getImm());
874
875  // Handle :upper16: and :lower16: assembly prefixes.
876  const MCExpr *E = MO.getExpr();
877  MCFixupKind Kind;
878  if (E->getKind() == MCExpr::Target) {
879    const ARMMCExpr *ARM16Expr = cast<ARMMCExpr>(E);
880    E = ARM16Expr->getSubExpr();
881
882    switch (ARM16Expr->getKind()) {
883    default: llvm_unreachable("Unsupported ARMFixup");
884    case ARMMCExpr::VK_ARM_HI16:
885      if (!isTargetDarwin() && EvaluateAsPCRel(E))
886        Kind = MCFixupKind(isThumb2()
887                           ? ARM::fixup_t2_movt_hi16_pcrel
888                           : ARM::fixup_arm_movt_hi16_pcrel);
889      else
890        Kind = MCFixupKind(isThumb2()
891                           ? ARM::fixup_t2_movt_hi16
892                           : ARM::fixup_arm_movt_hi16);
893      break;
894    case ARMMCExpr::VK_ARM_LO16:
895      if (!isTargetDarwin() && EvaluateAsPCRel(E))
896        Kind = MCFixupKind(isThumb2()
897                           ? ARM::fixup_t2_movw_lo16_pcrel
898                           : ARM::fixup_arm_movw_lo16_pcrel);
899      else
900        Kind = MCFixupKind(isThumb2()
901                           ? ARM::fixup_t2_movw_lo16
902                           : ARM::fixup_arm_movw_lo16);
903      break;
904    }
905    Fixups.push_back(MCFixup::Create(0, E, Kind, MI.getLoc()));
906    return 0;
907  }
908  // If the expression doesn't have :upper16: or :lower16: on it,
909  // it's just a plain immediate expression, and those evaluate to
910  // the lower 16 bits of the expression regardless of whether
911  // we have a movt or a movw.
912  if (!isTargetDarwin() && EvaluateAsPCRel(E))
913    Kind = MCFixupKind(isThumb2()
914                       ? ARM::fixup_t2_movw_lo16_pcrel
915                       : ARM::fixup_arm_movw_lo16_pcrel);
916  else
917    Kind = MCFixupKind(isThumb2()
918                       ? ARM::fixup_t2_movw_lo16
919                       : ARM::fixup_arm_movw_lo16);
920  Fixups.push_back(MCFixup::Create(0, E, Kind, MI.getLoc()));
921  return 0;
922}
923
924uint32_t ARMMCCodeEmitter::
925getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
926                    SmallVectorImpl<MCFixup> &Fixups) const {
927  const MCOperand &MO = MI.getOperand(OpIdx);
928  const MCOperand &MO1 = MI.getOperand(OpIdx+1);
929  const MCOperand &MO2 = MI.getOperand(OpIdx+2);
930  unsigned Rn = CTX.getRegisterInfo().getEncodingValue(MO.getReg());
931  unsigned Rm = CTX.getRegisterInfo().getEncodingValue(MO1.getReg());
932  unsigned ShImm = ARM_AM::getAM2Offset(MO2.getImm());
933  bool isAdd = ARM_AM::getAM2Op(MO2.getImm()) == ARM_AM::add;
934  ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(MO2.getImm());
935  unsigned SBits = getShiftOp(ShOp);
936
937  // While "lsr #32" and "asr #32" exist, they are encoded with a 0 in the shift
938  // amount. However, it would be an easy mistake to make so check here.
939  assert((ShImm & ~0x1f) == 0 && "Out of range shift amount");
940
941  // {16-13} = Rn
942  // {12}    = isAdd
943  // {11-0}  = shifter
944  //  {3-0}  = Rm
945  //  {4}    = 0
946  //  {6-5}  = type
947  //  {11-7} = imm
948  uint32_t Binary = Rm;
949  Binary |= Rn << 13;
950  Binary |= SBits << 5;
951  Binary |= ShImm << 7;
952  if (isAdd)
953    Binary |= 1 << 12;
954  return Binary;
955}
956
957uint32_t ARMMCCodeEmitter::
958getAddrMode2OpValue(const MCInst &MI, unsigned OpIdx,
959                    SmallVectorImpl<MCFixup> &Fixups) const {
960  // {17-14}  Rn
961  // {13}     1 == imm12, 0 == Rm
962  // {12}     isAdd
963  // {11-0}   imm12/Rm
964  const MCOperand &MO = MI.getOperand(OpIdx);
965  unsigned Rn = CTX.getRegisterInfo().getEncodingValue(MO.getReg());
966  uint32_t Binary = getAddrMode2OffsetOpValue(MI, OpIdx + 1, Fixups);
967  Binary |= Rn << 14;
968  return Binary;
969}
970
971uint32_t ARMMCCodeEmitter::
972getAddrMode2OffsetOpValue(const MCInst &MI, unsigned OpIdx,
973                          SmallVectorImpl<MCFixup> &Fixups) const {
974  // {13}     1 == imm12, 0 == Rm
975  // {12}     isAdd
976  // {11-0}   imm12/Rm
977  const MCOperand &MO = MI.getOperand(OpIdx);
978  const MCOperand &MO1 = MI.getOperand(OpIdx+1);
979  unsigned Imm = MO1.getImm();
980  bool isAdd = ARM_AM::getAM2Op(Imm) == ARM_AM::add;
981  bool isReg = MO.getReg() != 0;
982  uint32_t Binary = ARM_AM::getAM2Offset(Imm);
983  // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm12
984  if (isReg) {
985    ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(Imm);
986    Binary <<= 7;                    // Shift amount is bits [11:7]
987    Binary |= getShiftOp(ShOp) << 5; // Shift type is bits [6:5]
988    Binary |= CTX.getRegisterInfo().getEncodingValue(MO.getReg()); // Rm is bits [3:0]
989  }
990  return Binary | (isAdd << 12) | (isReg << 13);
991}
992
993uint32_t ARMMCCodeEmitter::
994getPostIdxRegOpValue(const MCInst &MI, unsigned OpIdx,
995                     SmallVectorImpl<MCFixup> &Fixups) const {
996  // {4}      isAdd
997  // {3-0}    Rm
998  const MCOperand &MO = MI.getOperand(OpIdx);
999  const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1000  bool isAdd = MO1.getImm() != 0;
1001  return CTX.getRegisterInfo().getEncodingValue(MO.getReg()) | (isAdd << 4);
1002}
1003
1004uint32_t ARMMCCodeEmitter::
1005getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
1006                          SmallVectorImpl<MCFixup> &Fixups) const {
1007  // {9}      1 == imm8, 0 == Rm
1008  // {8}      isAdd
1009  // {7-4}    imm7_4/zero
1010  // {3-0}    imm3_0/Rm
1011  const MCOperand &MO = MI.getOperand(OpIdx);
1012  const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1013  unsigned Imm = MO1.getImm();
1014  bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
1015  bool isImm = MO.getReg() == 0;
1016  uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
1017  // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
1018  if (!isImm)
1019    Imm8 = CTX.getRegisterInfo().getEncodingValue(MO.getReg());
1020  return Imm8 | (isAdd << 8) | (isImm << 9);
1021}
1022
1023uint32_t ARMMCCodeEmitter::
1024getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
1025                    SmallVectorImpl<MCFixup> &Fixups) const {
1026  // {13}     1 == imm8, 0 == Rm
1027  // {12-9}   Rn
1028  // {8}      isAdd
1029  // {7-4}    imm7_4/zero
1030  // {3-0}    imm3_0/Rm
1031  const MCOperand &MO = MI.getOperand(OpIdx);
1032  const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1033  const MCOperand &MO2 = MI.getOperand(OpIdx+2);
1034
1035  // If The first operand isn't a register, we have a label reference.
1036  if (!MO.isReg()) {
1037    unsigned Rn = CTX.getRegisterInfo().getEncodingValue(ARM::PC);   // Rn is PC.
1038
1039    assert(MO.isExpr() && "Unexpected machine operand type!");
1040    const MCExpr *Expr = MO.getExpr();
1041    MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_pcrel_10_unscaled);
1042    Fixups.push_back(MCFixup::Create(0, Expr, Kind, MI.getLoc()));
1043
1044    ++MCNumCPRelocations;
1045    return (Rn << 9) | (1 << 13);
1046  }
1047  unsigned Rn = CTX.getRegisterInfo().getEncodingValue(MO.getReg());
1048  unsigned Imm = MO2.getImm();
1049  bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
1050  bool isImm = MO1.getReg() == 0;
1051  uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
1052  // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
1053  if (!isImm)
1054    Imm8 = CTX.getRegisterInfo().getEncodingValue(MO1.getReg());
1055  return (Rn << 9) | Imm8 | (isAdd << 8) | (isImm << 13);
1056}
1057
1058/// getAddrModeThumbSPOpValue - Encode the t_addrmode_sp operands.
1059uint32_t ARMMCCodeEmitter::
1060getAddrModeThumbSPOpValue(const MCInst &MI, unsigned OpIdx,
1061                          SmallVectorImpl<MCFixup> &Fixups) const {
1062  // [SP, #imm]
1063  //   {7-0} = imm8
1064  const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1065  assert(MI.getOperand(OpIdx).getReg() == ARM::SP &&
1066         "Unexpected base register!");
1067
1068  // The immediate is already shifted for the implicit zeroes, so no change
1069  // here.
1070  return MO1.getImm() & 0xff;
1071}
1072
1073/// getAddrModeISOpValue - Encode the t_addrmode_is# operands.
1074uint32_t ARMMCCodeEmitter::
1075getAddrModeISOpValue(const MCInst &MI, unsigned OpIdx,
1076                     SmallVectorImpl<MCFixup> &Fixups) const {
1077  // [Rn, #imm]
1078  //   {7-3} = imm5
1079  //   {2-0} = Rn
1080  const MCOperand &MO = MI.getOperand(OpIdx);
1081  const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1082  unsigned Rn = CTX.getRegisterInfo().getEncodingValue(MO.getReg());
1083  unsigned Imm5 = MO1.getImm();
1084  return ((Imm5 & 0x1f) << 3) | Rn;
1085}
1086
1087/// getAddrModePCOpValue - Return encoding for t_addrmode_pc operands.
1088uint32_t ARMMCCodeEmitter::
1089getAddrModePCOpValue(const MCInst &MI, unsigned OpIdx,
1090                     SmallVectorImpl<MCFixup> &Fixups) const {
1091  const MCOperand MO = MI.getOperand(OpIdx);
1092  if (MO.isExpr())
1093    return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_cp, Fixups);
1094  return (MO.getImm() >> 2);
1095}
1096
1097/// getAddrMode5OpValue - Return encoding info for 'reg +/- imm10' operand.
1098uint32_t ARMMCCodeEmitter::
1099getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
1100                    SmallVectorImpl<MCFixup> &Fixups) const {
1101  // {12-9} = reg
1102  // {8}    = (U)nsigned (add == '1', sub == '0')
1103  // {7-0}  = imm8
1104  unsigned Reg, Imm8;
1105  bool isAdd;
1106  // If The first operand isn't a register, we have a label reference.
1107  const MCOperand &MO = MI.getOperand(OpIdx);
1108  if (!MO.isReg()) {
1109    Reg = CTX.getRegisterInfo().getEncodingValue(ARM::PC);   // Rn is PC.
1110    Imm8 = 0;
1111    isAdd = false; // 'U' bit is handled as part of the fixup.
1112
1113    assert(MO.isExpr() && "Unexpected machine operand type!");
1114    const MCExpr *Expr = MO.getExpr();
1115    MCFixupKind Kind;
1116    if (isThumb2())
1117      Kind = MCFixupKind(ARM::fixup_t2_pcrel_10);
1118    else
1119      Kind = MCFixupKind(ARM::fixup_arm_pcrel_10);
1120    Fixups.push_back(MCFixup::Create(0, Expr, Kind, MI.getLoc()));
1121
1122    ++MCNumCPRelocations;
1123  } else {
1124    EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups);
1125    isAdd = ARM_AM::getAM5Op(Imm8) == ARM_AM::add;
1126  }
1127
1128  uint32_t Binary = ARM_AM::getAM5Offset(Imm8);
1129  // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
1130  if (isAdd)
1131    Binary |= (1 << 8);
1132  Binary |= (Reg << 9);
1133  return Binary;
1134}
1135
1136unsigned ARMMCCodeEmitter::
1137getSORegRegOpValue(const MCInst &MI, unsigned OpIdx,
1138                SmallVectorImpl<MCFixup> &Fixups) const {
1139  // Sub-operands are [reg, reg, imm]. The first register is Rm, the reg to be
1140  // shifted. The second is Rs, the amount to shift by, and the third specifies
1141  // the type of the shift.
1142  //
1143  // {3-0} = Rm.
1144  // {4}   = 1
1145  // {6-5} = type
1146  // {11-8} = Rs
1147  // {7}    = 0
1148
1149  const MCOperand &MO  = MI.getOperand(OpIdx);
1150  const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1151  const MCOperand &MO2 = MI.getOperand(OpIdx + 2);
1152  ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO2.getImm());
1153
1154  // Encode Rm.
1155  unsigned Binary = CTX.getRegisterInfo().getEncodingValue(MO.getReg());
1156
1157  // Encode the shift opcode.
1158  unsigned SBits = 0;
1159  unsigned Rs = MO1.getReg();
1160  if (Rs) {
1161    // Set shift operand (bit[7:4]).
1162    // LSL - 0001
1163    // LSR - 0011
1164    // ASR - 0101
1165    // ROR - 0111
1166    switch (SOpc) {
1167    default: llvm_unreachable("Unknown shift opc!");
1168    case ARM_AM::lsl: SBits = 0x1; break;
1169    case ARM_AM::lsr: SBits = 0x3; break;
1170    case ARM_AM::asr: SBits = 0x5; break;
1171    case ARM_AM::ror: SBits = 0x7; break;
1172    }
1173  }
1174
1175  Binary |= SBits << 4;
1176
1177  // Encode the shift operation Rs.
1178  // Encode Rs bit[11:8].
1179  assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
1180  return Binary | (CTX.getRegisterInfo().getEncodingValue(Rs) << ARMII::RegRsShift);
1181}
1182
1183unsigned ARMMCCodeEmitter::
1184getSORegImmOpValue(const MCInst &MI, unsigned OpIdx,
1185                SmallVectorImpl<MCFixup> &Fixups) const {
1186  // Sub-operands are [reg, imm]. The first register is Rm, the reg to be
1187  // shifted. The second is the amount to shift by.
1188  //
1189  // {3-0} = Rm.
1190  // {4}   = 0
1191  // {6-5} = type
1192  // {11-7} = imm
1193
1194  const MCOperand &MO  = MI.getOperand(OpIdx);
1195  const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1196  ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO1.getImm());
1197
1198  // Encode Rm.
1199  unsigned Binary = CTX.getRegisterInfo().getEncodingValue(MO.getReg());
1200
1201  // Encode the shift opcode.
1202  unsigned SBits = 0;
1203
1204  // Set shift operand (bit[6:4]).
1205  // LSL - 000
1206  // LSR - 010
1207  // ASR - 100
1208  // ROR - 110
1209  // RRX - 110 and bit[11:8] clear.
1210  switch (SOpc) {
1211  default: llvm_unreachable("Unknown shift opc!");
1212  case ARM_AM::lsl: SBits = 0x0; break;
1213  case ARM_AM::lsr: SBits = 0x2; break;
1214  case ARM_AM::asr: SBits = 0x4; break;
1215  case ARM_AM::ror: SBits = 0x6; break;
1216  case ARM_AM::rrx:
1217    Binary |= 0x60;
1218    return Binary;
1219  }
1220
1221  // Encode shift_imm bit[11:7].
1222  Binary |= SBits << 4;
1223  unsigned Offset = ARM_AM::getSORegOffset(MO1.getImm());
1224  assert(Offset < 32 && "Offset must be in range 0-31!");
1225  return Binary | (Offset << 7);
1226}
1227
1228
1229unsigned ARMMCCodeEmitter::
1230getT2AddrModeSORegOpValue(const MCInst &MI, unsigned OpNum,
1231                SmallVectorImpl<MCFixup> &Fixups) const {
1232  const MCOperand &MO1 = MI.getOperand(OpNum);
1233  const MCOperand &MO2 = MI.getOperand(OpNum+1);
1234  const MCOperand &MO3 = MI.getOperand(OpNum+2);
1235
1236  // Encoded as [Rn, Rm, imm].
1237  // FIXME: Needs fixup support.
1238  unsigned Value = CTX.getRegisterInfo().getEncodingValue(MO1.getReg());
1239  Value <<= 4;
1240  Value |= CTX.getRegisterInfo().getEncodingValue(MO2.getReg());
1241  Value <<= 2;
1242  Value |= MO3.getImm();
1243
1244  return Value;
1245}
1246
1247unsigned ARMMCCodeEmitter::
1248getT2AddrModeImm8OpValue(const MCInst &MI, unsigned OpNum,
1249                         SmallVectorImpl<MCFixup> &Fixups) const {
1250  const MCOperand &MO1 = MI.getOperand(OpNum);
1251  const MCOperand &MO2 = MI.getOperand(OpNum+1);
1252
1253  // FIXME: Needs fixup support.
1254  unsigned Value = CTX.getRegisterInfo().getEncodingValue(MO1.getReg());
1255
1256  // Even though the immediate is 8 bits long, we need 9 bits in order
1257  // to represent the (inverse of the) sign bit.
1258  Value <<= 9;
1259  int32_t tmp = (int32_t)MO2.getImm();
1260  if (tmp < 0)
1261    tmp = abs(tmp);
1262  else
1263    Value |= 256; // Set the ADD bit
1264  Value |= tmp & 255;
1265  return Value;
1266}
1267
1268unsigned ARMMCCodeEmitter::
1269getT2AddrModeImm8OffsetOpValue(const MCInst &MI, unsigned OpNum,
1270                         SmallVectorImpl<MCFixup> &Fixups) const {
1271  const MCOperand &MO1 = MI.getOperand(OpNum);
1272
1273  // FIXME: Needs fixup support.
1274  unsigned Value = 0;
1275  int32_t tmp = (int32_t)MO1.getImm();
1276  if (tmp < 0)
1277    tmp = abs(tmp);
1278  else
1279    Value |= 256; // Set the ADD bit
1280  Value |= tmp & 255;
1281  return Value;
1282}
1283
1284unsigned ARMMCCodeEmitter::
1285getT2AddrModeImm12OffsetOpValue(const MCInst &MI, unsigned OpNum,
1286                         SmallVectorImpl<MCFixup> &Fixups) const {
1287  const MCOperand &MO1 = MI.getOperand(OpNum);
1288
1289  // FIXME: Needs fixup support.
1290  unsigned Value = 0;
1291  int32_t tmp = (int32_t)MO1.getImm();
1292  if (tmp < 0)
1293    tmp = abs(tmp);
1294  else
1295    Value |= 4096; // Set the ADD bit
1296  Value |= tmp & 4095;
1297  return Value;
1298}
1299
1300unsigned ARMMCCodeEmitter::
1301getT2SORegOpValue(const MCInst &MI, unsigned OpIdx,
1302                SmallVectorImpl<MCFixup> &Fixups) const {
1303  // Sub-operands are [reg, imm]. The first register is Rm, the reg to be
1304  // shifted. The second is the amount to shift by.
1305  //
1306  // {3-0} = Rm.
1307  // {4}   = 0
1308  // {6-5} = type
1309  // {11-7} = imm
1310
1311  const MCOperand &MO  = MI.getOperand(OpIdx);
1312  const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1313  ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO1.getImm());
1314
1315  // Encode Rm.
1316  unsigned Binary = CTX.getRegisterInfo().getEncodingValue(MO.getReg());
1317
1318  // Encode the shift opcode.
1319  unsigned SBits = 0;
1320  // Set shift operand (bit[6:4]).
1321  // LSL - 000
1322  // LSR - 010
1323  // ASR - 100
1324  // ROR - 110
1325  switch (SOpc) {
1326  default: llvm_unreachable("Unknown shift opc!");
1327  case ARM_AM::lsl: SBits = 0x0; break;
1328  case ARM_AM::lsr: SBits = 0x2; break;
1329  case ARM_AM::asr: SBits = 0x4; break;
1330  case ARM_AM::rrx: // FALLTHROUGH
1331  case ARM_AM::ror: SBits = 0x6; break;
1332  }
1333
1334  Binary |= SBits << 4;
1335  if (SOpc == ARM_AM::rrx)
1336    return Binary;
1337
1338  // Encode shift_imm bit[11:7].
1339  return Binary | ARM_AM::getSORegOffset(MO1.getImm()) << 7;
1340}
1341
1342unsigned ARMMCCodeEmitter::
1343getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
1344                               SmallVectorImpl<MCFixup> &Fixups) const {
1345  // 10 bits. lower 5 bits are are the lsb of the mask, high five bits are the
1346  // msb of the mask.
1347  const MCOperand &MO = MI.getOperand(Op);
1348  uint32_t v = ~MO.getImm();
1349  uint32_t lsb = CountTrailingZeros_32(v);
1350  uint32_t msb = (32 - CountLeadingZeros_32 (v)) - 1;
1351  assert (v != 0 && lsb < 32 && msb < 32 && "Illegal bitfield mask!");
1352  return lsb | (msb << 5);
1353}
1354
1355unsigned ARMMCCodeEmitter::
1356getRegisterListOpValue(const MCInst &MI, unsigned Op,
1357                       SmallVectorImpl<MCFixup> &Fixups) const {
1358  // VLDM/VSTM:
1359  //   {12-8} = Vd
1360  //   {7-0}  = Number of registers
1361  //
1362  // LDM/STM:
1363  //   {15-0}  = Bitfield of GPRs.
1364  unsigned Reg = MI.getOperand(Op).getReg();
1365  bool SPRRegs = ARMMCRegisterClasses[ARM::SPRRegClassID].contains(Reg);
1366  bool DPRRegs = ARMMCRegisterClasses[ARM::DPRRegClassID].contains(Reg);
1367
1368  unsigned Binary = 0;
1369
1370  if (SPRRegs || DPRRegs) {
1371    // VLDM/VSTM
1372    unsigned RegNo = CTX.getRegisterInfo().getEncodingValue(Reg);
1373    unsigned NumRegs = (MI.getNumOperands() - Op) & 0xff;
1374    Binary |= (RegNo & 0x1f) << 8;
1375    if (SPRRegs)
1376      Binary |= NumRegs;
1377    else
1378      Binary |= NumRegs * 2;
1379  } else {
1380    for (unsigned I = Op, E = MI.getNumOperands(); I < E; ++I) {
1381      unsigned RegNo = CTX.getRegisterInfo().getEncodingValue(MI.getOperand(I).getReg());
1382      Binary |= 1 << RegNo;
1383    }
1384  }
1385
1386  return Binary;
1387}
1388
1389/// getAddrMode6AddressOpValue - Encode an addrmode6 register number along
1390/// with the alignment operand.
1391unsigned ARMMCCodeEmitter::
1392getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
1393                           SmallVectorImpl<MCFixup> &Fixups) const {
1394  const MCOperand &Reg = MI.getOperand(Op);
1395  const MCOperand &Imm = MI.getOperand(Op + 1);
1396
1397  unsigned RegNo = CTX.getRegisterInfo().getEncodingValue(Reg.getReg());
1398  unsigned Align = 0;
1399
1400  switch (Imm.getImm()) {
1401  default: break;
1402  case 2:
1403  case 4:
1404  case 8:  Align = 0x01; break;
1405  case 16: Align = 0x02; break;
1406  case 32: Align = 0x03; break;
1407  }
1408
1409  return RegNo | (Align << 4);
1410}
1411
1412/// getAddrMode6OneLane32AddressOpValue - Encode an addrmode6 register number
1413/// along  with the alignment operand for use in VST1 and VLD1 with size 32.
1414unsigned ARMMCCodeEmitter::
1415getAddrMode6OneLane32AddressOpValue(const MCInst &MI, unsigned Op,
1416                                    SmallVectorImpl<MCFixup> &Fixups) const {
1417  const MCOperand &Reg = MI.getOperand(Op);
1418  const MCOperand &Imm = MI.getOperand(Op + 1);
1419
1420  unsigned RegNo = CTX.getRegisterInfo().getEncodingValue(Reg.getReg());
1421  unsigned Align = 0;
1422
1423  switch (Imm.getImm()) {
1424  default: break;
1425  case 8:
1426  case 16:
1427  case 32: // Default '0' value for invalid alignments of 8, 16, 32 bytes.
1428  case 2: Align = 0x00; break;
1429  case 4: Align = 0x03; break;
1430  }
1431
1432  return RegNo | (Align << 4);
1433}
1434
1435
1436/// getAddrMode6DupAddressOpValue - Encode an addrmode6 register number and
1437/// alignment operand for use in VLD-dup instructions.  This is the same as
1438/// getAddrMode6AddressOpValue except for the alignment encoding, which is
1439/// different for VLD4-dup.
1440unsigned ARMMCCodeEmitter::
1441getAddrMode6DupAddressOpValue(const MCInst &MI, unsigned Op,
1442                              SmallVectorImpl<MCFixup> &Fixups) const {
1443  const MCOperand &Reg = MI.getOperand(Op);
1444  const MCOperand &Imm = MI.getOperand(Op + 1);
1445
1446  unsigned RegNo = CTX.getRegisterInfo().getEncodingValue(Reg.getReg());
1447  unsigned Align = 0;
1448
1449  switch (Imm.getImm()) {
1450  default: break;
1451  case 2:
1452  case 4:
1453  case 8:  Align = 0x01; break;
1454  case 16: Align = 0x03; break;
1455  }
1456
1457  return RegNo | (Align << 4);
1458}
1459
1460unsigned ARMMCCodeEmitter::
1461getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
1462                          SmallVectorImpl<MCFixup> &Fixups) const {
1463  const MCOperand &MO = MI.getOperand(Op);
1464  if (MO.getReg() == 0) return 0x0D;
1465  return CTX.getRegisterInfo().getEncodingValue(MO.getReg());
1466}
1467
1468unsigned ARMMCCodeEmitter::
1469getShiftRight8Imm(const MCInst &MI, unsigned Op,
1470                  SmallVectorImpl<MCFixup> &Fixups) const {
1471  return 8 - MI.getOperand(Op).getImm();
1472}
1473
1474unsigned ARMMCCodeEmitter::
1475getShiftRight16Imm(const MCInst &MI, unsigned Op,
1476                   SmallVectorImpl<MCFixup> &Fixups) const {
1477  return 16 - MI.getOperand(Op).getImm();
1478}
1479
1480unsigned ARMMCCodeEmitter::
1481getShiftRight32Imm(const MCInst &MI, unsigned Op,
1482                   SmallVectorImpl<MCFixup> &Fixups) const {
1483  return 32 - MI.getOperand(Op).getImm();
1484}
1485
1486unsigned ARMMCCodeEmitter::
1487getShiftRight64Imm(const MCInst &MI, unsigned Op,
1488                   SmallVectorImpl<MCFixup> &Fixups) const {
1489  return 64 - MI.getOperand(Op).getImm();
1490}
1491
1492void ARMMCCodeEmitter::
1493EncodeInstruction(const MCInst &MI, raw_ostream &OS,
1494                  SmallVectorImpl<MCFixup> &Fixups) const {
1495  // Pseudo instructions don't get encoded.
1496  const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
1497  uint64_t TSFlags = Desc.TSFlags;
1498  if ((TSFlags & ARMII::FormMask) == ARMII::Pseudo)
1499    return;
1500
1501  int Size;
1502  if (Desc.getSize() == 2 || Desc.getSize() == 4)
1503    Size = Desc.getSize();
1504  else
1505    llvm_unreachable("Unexpected instruction size!");
1506
1507  uint32_t Binary = getBinaryCodeForInstr(MI, Fixups);
1508  // Thumb 32-bit wide instructions need to emit the high order halfword
1509  // first.
1510  if (isThumb() && Size == 4) {
1511    EmitConstant(Binary >> 16, 2, OS);
1512    EmitConstant(Binary & 0xffff, 2, OS);
1513  } else
1514    EmitConstant(Binary, Size, OS);
1515  ++MCNumEmitted;  // Keep track of the # of mi's emitted.
1516}
1517
1518#include "ARMGenMCCodeEmitter.inc"
1519