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 #include "MCTargetDesc/ARMAddressingModes.h"
15 #include "MCTargetDesc/ARMBaseInfo.h"
16 #include "MCTargetDesc/ARMFixupKinds.h"
17 #include "MCTargetDesc/ARMMCExpr.h"
18 #include "llvm/ADT/APFloat.h"
19 #include "llvm/ADT/APInt.h"
20 #include "llvm/ADT/SmallVector.h"
21 #include "llvm/ADT/Statistic.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/MC/MCCodeEmitter.h"
24 #include "llvm/MC/MCContext.h"
25 #include "llvm/MC/MCExpr.h"
26 #include "llvm/MC/MCFixup.h"
27 #include "llvm/MC/MCInst.h"
28 #include "llvm/MC/MCInstrDesc.h"
29 #include "llvm/MC/MCInstrInfo.h"
30 #include "llvm/MC/MCRegisterInfo.h"
31 #include "llvm/MC/MCSubtargetInfo.h"
32 #include "llvm/Support/Casting.h"
33 #include "llvm/Support/Compiler.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include "llvm/Support/MathExtras.h"
36 #include "llvm/Support/raw_ostream.h"
37 #include <algorithm>
38 #include <cassert>
39 #include <cstdint>
40 #include <cstdlib>
41 
42 using namespace llvm;
43 
44 #define DEBUG_TYPE "mccodeemitter"
45 
46 STATISTIC(MCNumEmitted, "Number of MC instructions emitted.");
47 STATISTIC(MCNumCPRelocations, "Number of constant pool relocations created.");
48 
49 namespace {
50 
51 class ARMMCCodeEmitter : public MCCodeEmitter {
52   const MCInstrInfo &MCII;
53   const MCContext &CTX;
54   bool IsLittleEndian;
55 
56 public:
57   ARMMCCodeEmitter(const MCInstrInfo &mcii, MCContext &ctx, bool IsLittle)
58     : MCII(mcii), CTX(ctx), IsLittleEndian(IsLittle) {
59   }
60   ARMMCCodeEmitter(const ARMMCCodeEmitter &) = delete;
61   ARMMCCodeEmitter &operator=(const ARMMCCodeEmitter &) = delete;
62   ~ARMMCCodeEmitter() override = default;
63 
64   bool isThumb(const MCSubtargetInfo &STI) const {
65     return STI.getFeatureBits()[ARM::ModeThumb];
66   }
67 
68   bool isThumb2(const MCSubtargetInfo &STI) const {
69     return isThumb(STI) && STI.getFeatureBits()[ARM::FeatureThumb2];
70   }
71 
72   bool isTargetMachO(const MCSubtargetInfo &STI) const {
73     const Triple &TT = STI.getTargetTriple();
74     return TT.isOSBinFormatMachO();
75   }
76 
77   unsigned getMachineSoImmOpValue(unsigned SoImm) const;
78 
79   // getBinaryCodeForInstr - TableGen'erated function for getting the
80   // binary encoding for an instruction.
81   uint64_t getBinaryCodeForInstr(const MCInst &MI,
82                                  SmallVectorImpl<MCFixup> &Fixups,
83                                  const MCSubtargetInfo &STI) const;
84 
85   /// getMachineOpValue - Return binary encoding of operand. If the machine
86   /// operand requires relocation, record the relocation and return zero.
87   unsigned getMachineOpValue(const MCInst &MI,const MCOperand &MO,
88                              SmallVectorImpl<MCFixup> &Fixups,
89                              const MCSubtargetInfo &STI) const;
90 
91   /// getHiLo16ImmOpValue - Return the encoding for the hi / low 16-bit of
92   /// the specified operand. This is used for operands with :lower16: and
93   /// :upper16: prefixes.
94   uint32_t getHiLo16ImmOpValue(const MCInst &MI, unsigned OpIdx,
95                                SmallVectorImpl<MCFixup> &Fixups,
96                                const MCSubtargetInfo &STI) const;
97 
98   bool EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx,
99                               unsigned &Reg, unsigned &Imm,
100                               SmallVectorImpl<MCFixup> &Fixups,
101                               const MCSubtargetInfo &STI) const;
102 
103   /// getThumbBLTargetOpValue - Return encoding info for Thumb immediate
104   /// BL branch target.
105   uint32_t getThumbBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
106                                    SmallVectorImpl<MCFixup> &Fixups,
107                                    const MCSubtargetInfo &STI) const;
108 
109   /// getThumbBLXTargetOpValue - Return encoding info for Thumb immediate
110   /// BLX branch target.
111   uint32_t getThumbBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
112                                     SmallVectorImpl<MCFixup> &Fixups,
113                                     const MCSubtargetInfo &STI) const;
114 
115   /// getThumbBRTargetOpValue - Return encoding info for Thumb branch target.
116   uint32_t getThumbBRTargetOpValue(const MCInst &MI, unsigned OpIdx,
117                                    SmallVectorImpl<MCFixup> &Fixups,
118                                    const MCSubtargetInfo &STI) const;
119 
120   /// getThumbBCCTargetOpValue - Return encoding info for Thumb branch target.
121   uint32_t getThumbBCCTargetOpValue(const MCInst &MI, unsigned OpIdx,
122                                     SmallVectorImpl<MCFixup> &Fixups,
123                                     const MCSubtargetInfo &STI) const;
124 
125   /// getThumbCBTargetOpValue - Return encoding info for Thumb branch target.
126   uint32_t getThumbCBTargetOpValue(const MCInst &MI, unsigned OpIdx,
127                                    SmallVectorImpl<MCFixup> &Fixups,
128                                    const MCSubtargetInfo &STI) const;
129 
130   /// getBranchTargetOpValue - Return encoding info for 24-bit immediate
131   /// branch target.
132   uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
133                                   SmallVectorImpl<MCFixup> &Fixups,
134                                   const MCSubtargetInfo &STI) const;
135 
136   /// getThumbBranchTargetOpValue - Return encoding info for 24-bit
137   /// immediate Thumb2 direct branch target.
138   uint32_t getThumbBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
139                                        SmallVectorImpl<MCFixup> &Fixups,
140                                        const MCSubtargetInfo &STI) const;
141 
142   /// getARMBranchTargetOpValue - Return encoding info for 24-bit immediate
143   /// branch target.
144   uint32_t getARMBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
145                                      SmallVectorImpl<MCFixup> &Fixups,
146                                      const MCSubtargetInfo &STI) const;
147   uint32_t getARMBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
148                                  SmallVectorImpl<MCFixup> &Fixups,
149                                  const MCSubtargetInfo &STI) const;
150   uint32_t getARMBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
151                                   SmallVectorImpl<MCFixup> &Fixups,
152                                   const MCSubtargetInfo &STI) const;
153 
154   /// getAdrLabelOpValue - Return encoding info for 12-bit immediate
155   /// ADR label target.
156   uint32_t getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
157                               SmallVectorImpl<MCFixup> &Fixups,
158                               const MCSubtargetInfo &STI) const;
159   uint32_t getThumbAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
160                               SmallVectorImpl<MCFixup> &Fixups,
161                               const MCSubtargetInfo &STI) const;
162   uint32_t getT2AdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
163                               SmallVectorImpl<MCFixup> &Fixups,
164                               const MCSubtargetInfo &STI) const;
165 
166 
167   /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12'
168   /// operand.
169   uint32_t getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
170                                    SmallVectorImpl<MCFixup> &Fixups,
171                                    const MCSubtargetInfo &STI) const;
172 
173   /// getThumbAddrModeRegRegOpValue - Return encoding for 'reg + reg' operand.
174   uint32_t getThumbAddrModeRegRegOpValue(const MCInst &MI, unsigned OpIdx,
175                                          SmallVectorImpl<MCFixup> &Fixups,
176                                          const MCSubtargetInfo &STI) const;
177 
178   /// getT2AddrModeImm8s4OpValue - Return encoding info for 'reg +/- imm8<<2'
179   /// operand.
180   uint32_t getT2AddrModeImm8s4OpValue(const MCInst &MI, unsigned OpIdx,
181                                    SmallVectorImpl<MCFixup> &Fixups,
182                                    const MCSubtargetInfo &STI) const;
183 
184   /// getT2AddrModeImm0_1020s4OpValue - Return encoding info for 'reg + imm8<<2'
185   /// operand.
186   uint32_t getT2AddrModeImm0_1020s4OpValue(const MCInst &MI, unsigned OpIdx,
187                                    SmallVectorImpl<MCFixup> &Fixups,
188                                    const MCSubtargetInfo &STI) const;
189 
190   /// getT2Imm8s4OpValue - Return encoding info for '+/- imm8<<2'
191   /// operand.
192   uint32_t getT2Imm8s4OpValue(const MCInst &MI, unsigned OpIdx,
193                               SmallVectorImpl<MCFixup> &Fixups,
194                               const MCSubtargetInfo &STI) const;
195 
196 
197   /// getLdStSORegOpValue - Return encoding info for 'reg +/- reg shop imm'
198   /// operand as needed by load/store instructions.
199   uint32_t getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
200                                SmallVectorImpl<MCFixup> &Fixups,
201                                const MCSubtargetInfo &STI) const;
202 
203   /// getLdStmModeOpValue - Return encoding for load/store multiple mode.
204   uint32_t getLdStmModeOpValue(const MCInst &MI, unsigned OpIdx,
205                                SmallVectorImpl<MCFixup> &Fixups,
206                                const MCSubtargetInfo &STI) const {
207     ARM_AM::AMSubMode Mode = (ARM_AM::AMSubMode)MI.getOperand(OpIdx).getImm();
208     switch (Mode) {
209     default: llvm_unreachable("Unknown addressing sub-mode!");
210     case ARM_AM::da: return 0;
211     case ARM_AM::ia: return 1;
212     case ARM_AM::db: return 2;
213     case ARM_AM::ib: return 3;
214     }
215   }
216 
217   /// getShiftOp - Return the shift opcode (bit[6:5]) of the immediate value.
218   ///
219   unsigned getShiftOp(ARM_AM::ShiftOpc ShOpc) const {
220     switch (ShOpc) {
221     case ARM_AM::no_shift:
222     case ARM_AM::lsl: return 0;
223     case ARM_AM::lsr: return 1;
224     case ARM_AM::asr: return 2;
225     case ARM_AM::ror:
226     case ARM_AM::rrx: return 3;
227     }
228     llvm_unreachable("Invalid ShiftOpc!");
229   }
230 
231   /// getAddrMode2OffsetOpValue - Return encoding for am2offset operands.
232   uint32_t getAddrMode2OffsetOpValue(const MCInst &MI, unsigned OpIdx,
233                                      SmallVectorImpl<MCFixup> &Fixups,
234                                      const MCSubtargetInfo &STI) const;
235 
236   /// getPostIdxRegOpValue - Return encoding for postidx_reg operands.
237   uint32_t getPostIdxRegOpValue(const MCInst &MI, unsigned OpIdx,
238                                 SmallVectorImpl<MCFixup> &Fixups,
239                                 const MCSubtargetInfo &STI) const;
240 
241   /// getAddrMode3OffsetOpValue - Return encoding for am3offset operands.
242   uint32_t getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
243                                      SmallVectorImpl<MCFixup> &Fixups,
244                                      const MCSubtargetInfo &STI) const;
245 
246   /// getAddrMode3OpValue - Return encoding for addrmode3 operands.
247   uint32_t getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
248                                SmallVectorImpl<MCFixup> &Fixups,
249                                const MCSubtargetInfo &STI) const;
250 
251   /// getAddrModeThumbSPOpValue - Return encoding info for 'reg +/- imm12'
252   /// operand.
253   uint32_t getAddrModeThumbSPOpValue(const MCInst &MI, unsigned OpIdx,
254                                      SmallVectorImpl<MCFixup> &Fixups,
255                                      const MCSubtargetInfo &STI) const;
256 
257   /// getAddrModeISOpValue - Encode the t_addrmode_is# operands.
258   uint32_t getAddrModeISOpValue(const MCInst &MI, unsigned OpIdx,
259                                 SmallVectorImpl<MCFixup> &Fixups,
260                                 const MCSubtargetInfo &STI) const;
261 
262   /// getAddrModePCOpValue - Return encoding for t_addrmode_pc operands.
263   uint32_t getAddrModePCOpValue(const MCInst &MI, unsigned OpIdx,
264                                 SmallVectorImpl<MCFixup> &Fixups,
265                                 const MCSubtargetInfo &STI) const;
266 
267   /// getAddrMode5OpValue - Return encoding info for 'reg +/- (imm8 << 2)' operand.
268   uint32_t getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
269                                SmallVectorImpl<MCFixup> &Fixups,
270                                const MCSubtargetInfo &STI) const;
271 
272   /// getAddrMode5FP16OpValue - Return encoding info for 'reg +/- (imm8 << 1)' operand.
273   uint32_t getAddrMode5FP16OpValue(const MCInst &MI, unsigned OpIdx,
274                                SmallVectorImpl<MCFixup> &Fixups,
275                                const MCSubtargetInfo &STI) const;
276 
277   /// getCCOutOpValue - Return encoding of the 's' bit.
278   unsigned getCCOutOpValue(const MCInst &MI, unsigned Op,
279                            SmallVectorImpl<MCFixup> &Fixups,
280                            const MCSubtargetInfo &STI) const {
281     // The operand is either reg0 or CPSR. The 's' bit is encoded as '0' or
282     // '1' respectively.
283     return MI.getOperand(Op).getReg() == ARM::CPSR;
284   }
285 
286   /// getSOImmOpValue - Return an encoded 12-bit shifted-immediate value.
287   unsigned getSOImmOpValue(const MCInst &MI, unsigned Op,
288                            SmallVectorImpl<MCFixup> &Fixups,
289                            const MCSubtargetInfo &STI) const {
290     const MCOperand &MO = MI.getOperand(Op);
291 
292     // We expect MO to be an immediate or an expression,
293     // if it is an immediate - that's fine, just encode the value.
294     // Otherwise - create a Fixup.
295     if (MO.isExpr()) {
296       const MCExpr *Expr = MO.getExpr();
297       // In instruction code this value always encoded as lowest 12 bits,
298       // so we don't have to perform any specific adjustments.
299       // Due to requirements of relocatable records we have to use FK_Data_4.
300       // See ARMELFObjectWriter::ExplicitRelSym and
301       //     ARMELFObjectWriter::GetRelocTypeInner for more details.
302       MCFixupKind Kind = MCFixupKind(FK_Data_4);
303       Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
304       return 0;
305     }
306 
307     unsigned SoImm = MO.getImm();
308     int SoImmVal = ARM_AM::getSOImmVal(SoImm);
309     assert(SoImmVal != -1 && "Not a valid so_imm value!");
310 
311     // Encode rotate_imm.
312     unsigned Binary = (ARM_AM::getSOImmValRot((unsigned)SoImmVal) >> 1)
313       << ARMII::SoRotImmShift;
314 
315     // Encode immed_8.
316     Binary |= ARM_AM::getSOImmValImm((unsigned)SoImmVal);
317     return Binary;
318   }
319 
320   unsigned getModImmOpValue(const MCInst &MI, unsigned Op,
321                             SmallVectorImpl<MCFixup> &Fixups,
322                             const MCSubtargetInfo &ST) const {
323     const MCOperand &MO = MI.getOperand(Op);
324 
325     // Support for fixups (MCFixup)
326     if (MO.isExpr()) {
327       const MCExpr *Expr = MO.getExpr();
328       // Fixups resolve to plain values that need to be encoded.
329       MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_mod_imm);
330       Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
331       return 0;
332     }
333 
334     // Immediate is already in its encoded format
335     return MO.getImm();
336   }
337 
338   /// getT2SOImmOpValue - Return an encoded 12-bit shifted-immediate value.
339   unsigned getT2SOImmOpValue(const MCInst &MI, unsigned Op,
340                            SmallVectorImpl<MCFixup> &Fixups,
341                            const MCSubtargetInfo &STI) const {
342     unsigned SoImm = MI.getOperand(Op).getImm();
343     unsigned Encoded =  ARM_AM::getT2SOImmVal(SoImm);
344     assert(Encoded != ~0U && "Not a Thumb2 so_imm value?");
345     return Encoded;
346   }
347 
348   unsigned getT2AddrModeSORegOpValue(const MCInst &MI, unsigned OpNum,
349     SmallVectorImpl<MCFixup> &Fixups,
350     const MCSubtargetInfo &STI) const;
351   unsigned getT2AddrModeImm8OpValue(const MCInst &MI, unsigned OpNum,
352     SmallVectorImpl<MCFixup> &Fixups,
353     const MCSubtargetInfo &STI) const;
354   unsigned getT2AddrModeImm8OffsetOpValue(const MCInst &MI, unsigned OpNum,
355     SmallVectorImpl<MCFixup> &Fixups,
356     const MCSubtargetInfo &STI) const;
357 
358   /// getSORegOpValue - Return an encoded so_reg shifted register value.
359   unsigned getSORegRegOpValue(const MCInst &MI, unsigned Op,
360                            SmallVectorImpl<MCFixup> &Fixups,
361                            const MCSubtargetInfo &STI) const;
362   unsigned getSORegImmOpValue(const MCInst &MI, unsigned Op,
363                            SmallVectorImpl<MCFixup> &Fixups,
364                            const MCSubtargetInfo &STI) const;
365   unsigned getT2SORegOpValue(const MCInst &MI, unsigned Op,
366                              SmallVectorImpl<MCFixup> &Fixups,
367                              const MCSubtargetInfo &STI) const;
368 
369   unsigned getNEONVcvtImm32OpValue(const MCInst &MI, unsigned Op,
370                                    SmallVectorImpl<MCFixup> &Fixups,
371                                    const MCSubtargetInfo &STI) const {
372     return 64 - MI.getOperand(Op).getImm();
373   }
374 
375   unsigned getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
376                                       SmallVectorImpl<MCFixup> &Fixups,
377                                       const MCSubtargetInfo &STI) const;
378 
379   unsigned getRegisterListOpValue(const MCInst &MI, unsigned Op,
380                                   SmallVectorImpl<MCFixup> &Fixups,
381                                   const MCSubtargetInfo &STI) const;
382   unsigned getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
383                                       SmallVectorImpl<MCFixup> &Fixups,
384                                       const MCSubtargetInfo &STI) const;
385   unsigned getAddrMode6OneLane32AddressOpValue(const MCInst &MI, unsigned Op,
386                                         SmallVectorImpl<MCFixup> &Fixups,
387                                         const MCSubtargetInfo &STI) const;
388   unsigned getAddrMode6DupAddressOpValue(const MCInst &MI, unsigned Op,
389                                         SmallVectorImpl<MCFixup> &Fixups,
390                                         const MCSubtargetInfo &STI) const;
391   unsigned getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
392                                      SmallVectorImpl<MCFixup> &Fixups,
393                                      const MCSubtargetInfo &STI) const;
394 
395   unsigned getShiftRight8Imm(const MCInst &MI, unsigned Op,
396                              SmallVectorImpl<MCFixup> &Fixups,
397                              const MCSubtargetInfo &STI) const;
398   unsigned getShiftRight16Imm(const MCInst &MI, unsigned Op,
399                               SmallVectorImpl<MCFixup> &Fixups,
400                               const MCSubtargetInfo &STI) const;
401   unsigned getShiftRight32Imm(const MCInst &MI, unsigned Op,
402                               SmallVectorImpl<MCFixup> &Fixups,
403                               const MCSubtargetInfo &STI) const;
404   unsigned getShiftRight64Imm(const MCInst &MI, unsigned Op,
405                               SmallVectorImpl<MCFixup> &Fixups,
406                               const MCSubtargetInfo &STI) const;
407 
408   unsigned getThumbSRImmOpValue(const MCInst &MI, unsigned Op,
409                                  SmallVectorImpl<MCFixup> &Fixups,
410                                  const MCSubtargetInfo &STI) const;
411 
412   unsigned NEONThumb2DataIPostEncoder(const MCInst &MI,
413                                       unsigned EncodedValue,
414                                       const MCSubtargetInfo &STI) const;
415   unsigned NEONThumb2LoadStorePostEncoder(const MCInst &MI,
416                                           unsigned EncodedValue,
417                                           const MCSubtargetInfo &STI) const;
418   unsigned NEONThumb2DupPostEncoder(const MCInst &MI,
419                                     unsigned EncodedValue,
420                                     const MCSubtargetInfo &STI) const;
421   unsigned NEONThumb2V8PostEncoder(const MCInst &MI,
422                                    unsigned EncodedValue,
423                                    const MCSubtargetInfo &STI) const;
424 
425   unsigned VFPThumb2PostEncoder(const MCInst &MI,
426                                 unsigned EncodedValue,
427                                 const MCSubtargetInfo &STI) const;
428 
429   void EmitByte(unsigned char C, raw_ostream &OS) const {
430     OS << (char)C;
431   }
432 
433   void EmitConstant(uint64_t Val, unsigned Size, raw_ostream &OS) const {
434     // Output the constant in little endian byte order.
435     for (unsigned i = 0; i != Size; ++i) {
436       unsigned Shift = IsLittleEndian ? i * 8 : (Size - 1 - i) * 8;
437       EmitByte((Val >> Shift) & 0xff, OS);
438     }
439   }
440 
441   void encodeInstruction(const MCInst &MI, raw_ostream &OS,
442                          SmallVectorImpl<MCFixup> &Fixups,
443                          const MCSubtargetInfo &STI) const override;
444 };
445 
446 } // end anonymous namespace
447 
448 /// NEONThumb2DataIPostEncoder - Post-process encoded NEON data-processing
449 /// instructions, and rewrite them to their Thumb2 form if we are currently in
450 /// Thumb2 mode.
451 unsigned ARMMCCodeEmitter::NEONThumb2DataIPostEncoder(const MCInst &MI,
452                                                  unsigned EncodedValue,
453                                                  const MCSubtargetInfo &STI) const {
454   if (isThumb2(STI)) {
455     // NEON Thumb2 data-processsing encodings are very simple: bit 24 is moved
456     // to bit 12 of the high half-word (i.e. bit 28), and bits 27-24 are
457     // set to 1111.
458     unsigned Bit24 = EncodedValue & 0x01000000;
459     unsigned Bit28 = Bit24 << 4;
460     EncodedValue &= 0xEFFFFFFF;
461     EncodedValue |= Bit28;
462     EncodedValue |= 0x0F000000;
463   }
464 
465   return EncodedValue;
466 }
467 
468 /// NEONThumb2LoadStorePostEncoder - Post-process encoded NEON load/store
469 /// instructions, and rewrite them to their Thumb2 form if we are currently in
470 /// Thumb2 mode.
471 unsigned ARMMCCodeEmitter::NEONThumb2LoadStorePostEncoder(const MCInst &MI,
472                                                  unsigned EncodedValue,
473                                                  const MCSubtargetInfo &STI) const {
474   if (isThumb2(STI)) {
475     EncodedValue &= 0xF0FFFFFF;
476     EncodedValue |= 0x09000000;
477   }
478 
479   return EncodedValue;
480 }
481 
482 /// NEONThumb2DupPostEncoder - Post-process encoded NEON vdup
483 /// instructions, and rewrite them to their Thumb2 form if we are currently in
484 /// Thumb2 mode.
485 unsigned ARMMCCodeEmitter::NEONThumb2DupPostEncoder(const MCInst &MI,
486                                                  unsigned EncodedValue,
487                                                  const MCSubtargetInfo &STI) const {
488   if (isThumb2(STI)) {
489     EncodedValue &= 0x00FFFFFF;
490     EncodedValue |= 0xEE000000;
491   }
492 
493   return EncodedValue;
494 }
495 
496 /// Post-process encoded NEON v8 instructions, and rewrite them to Thumb2 form
497 /// if we are in Thumb2.
498 unsigned ARMMCCodeEmitter::NEONThumb2V8PostEncoder(const MCInst &MI,
499                                                  unsigned EncodedValue,
500                                                  const MCSubtargetInfo &STI) const {
501   if (isThumb2(STI)) {
502     EncodedValue |= 0xC000000; // Set bits 27-26
503   }
504 
505   return EncodedValue;
506 }
507 
508 /// VFPThumb2PostEncoder - Post-process encoded VFP instructions and rewrite
509 /// them to their Thumb2 form if we are currently in Thumb2 mode.
510 unsigned ARMMCCodeEmitter::
511 VFPThumb2PostEncoder(const MCInst &MI, unsigned EncodedValue,
512                      const MCSubtargetInfo &STI) const {
513   if (isThumb2(STI)) {
514     EncodedValue &= 0x0FFFFFFF;
515     EncodedValue |= 0xE0000000;
516   }
517   return EncodedValue;
518 }
519 
520 /// getMachineOpValue - Return binary encoding of operand. If the machine
521 /// operand requires relocation, record the relocation and return zero.
522 unsigned ARMMCCodeEmitter::
523 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
524                   SmallVectorImpl<MCFixup> &Fixups,
525                   const MCSubtargetInfo &STI) const {
526   if (MO.isReg()) {
527     unsigned Reg = MO.getReg();
528     unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg);
529 
530     // Q registers are encoded as 2x their register number.
531     switch (Reg) {
532     default:
533       return RegNo;
534     case ARM::Q0:  case ARM::Q1:  case ARM::Q2:  case ARM::Q3:
535     case ARM::Q4:  case ARM::Q5:  case ARM::Q6:  case ARM::Q7:
536     case ARM::Q8:  case ARM::Q9:  case ARM::Q10: case ARM::Q11:
537     case ARM::Q12: case ARM::Q13: case ARM::Q14: case ARM::Q15:
538       return 2 * RegNo;
539     }
540   } else if (MO.isImm()) {
541     return static_cast<unsigned>(MO.getImm());
542   } else if (MO.isFPImm()) {
543     return static_cast<unsigned>(APFloat(MO.getFPImm())
544                      .bitcastToAPInt().getHiBits(32).getLimitedValue());
545   }
546 
547   llvm_unreachable("Unable to encode MCOperand!");
548 }
549 
550 /// getAddrModeImmOpValue - Return encoding info for 'reg +/- imm' operand.
551 bool ARMMCCodeEmitter::
552 EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx, unsigned &Reg,
553                        unsigned &Imm, SmallVectorImpl<MCFixup> &Fixups,
554                        const MCSubtargetInfo &STI) const {
555   const MCOperand &MO  = MI.getOperand(OpIdx);
556   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
557 
558   Reg = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
559 
560   int32_t SImm = MO1.getImm();
561   bool isAdd = true;
562 
563   // Special value for #-0
564   if (SImm == INT32_MIN) {
565     SImm = 0;
566     isAdd = false;
567   }
568 
569   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
570   if (SImm < 0) {
571     SImm = -SImm;
572     isAdd = false;
573   }
574 
575   Imm = SImm;
576   return isAdd;
577 }
578 
579 /// getBranchTargetOpValue - Helper function to get the branch target operand,
580 /// which is either an immediate or requires a fixup.
581 static uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
582                                        unsigned FixupKind,
583                                        SmallVectorImpl<MCFixup> &Fixups,
584                                        const MCSubtargetInfo &STI) {
585   const MCOperand &MO = MI.getOperand(OpIdx);
586 
587   // If the destination is an immediate, we have nothing to do.
588   if (MO.isImm()) return MO.getImm();
589   assert(MO.isExpr() && "Unexpected branch target type!");
590   const MCExpr *Expr = MO.getExpr();
591   MCFixupKind Kind = MCFixupKind(FixupKind);
592   Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
593 
594   // All of the information is in the fixup.
595   return 0;
596 }
597 
598 // Thumb BL and BLX use a strange offset encoding where bits 22 and 21 are
599 // determined by negating them and XOR'ing them with bit 23.
600 static int32_t encodeThumbBLOffset(int32_t offset) {
601   offset >>= 1;
602   uint32_t S  = (offset & 0x800000) >> 23;
603   uint32_t J1 = (offset & 0x400000) >> 22;
604   uint32_t J2 = (offset & 0x200000) >> 21;
605   J1 = (~J1 & 0x1);
606   J2 = (~J2 & 0x1);
607   J1 ^= S;
608   J2 ^= S;
609 
610   offset &= ~0x600000;
611   offset |= J1 << 22;
612   offset |= J2 << 21;
613 
614   return offset;
615 }
616 
617 /// getThumbBLTargetOpValue - Return encoding info for immediate branch target.
618 uint32_t ARMMCCodeEmitter::
619 getThumbBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
620                         SmallVectorImpl<MCFixup> &Fixups,
621                         const MCSubtargetInfo &STI) const {
622   const MCOperand MO = MI.getOperand(OpIdx);
623   if (MO.isExpr())
624     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_bl,
625                                     Fixups, STI);
626   return encodeThumbBLOffset(MO.getImm());
627 }
628 
629 /// getThumbBLXTargetOpValue - Return encoding info for Thumb immediate
630 /// BLX branch target.
631 uint32_t ARMMCCodeEmitter::
632 getThumbBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
633                          SmallVectorImpl<MCFixup> &Fixups,
634                          const MCSubtargetInfo &STI) const {
635   const MCOperand MO = MI.getOperand(OpIdx);
636   if (MO.isExpr())
637     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_blx,
638                                     Fixups, STI);
639   return encodeThumbBLOffset(MO.getImm());
640 }
641 
642 /// getThumbBRTargetOpValue - Return encoding info for Thumb branch target.
643 uint32_t ARMMCCodeEmitter::
644 getThumbBRTargetOpValue(const MCInst &MI, unsigned OpIdx,
645                         SmallVectorImpl<MCFixup> &Fixups,
646                         const MCSubtargetInfo &STI) const {
647   const MCOperand MO = MI.getOperand(OpIdx);
648   if (MO.isExpr())
649     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_br,
650                                     Fixups, STI);
651   return (MO.getImm() >> 1);
652 }
653 
654 /// getThumbBCCTargetOpValue - Return encoding info for Thumb branch target.
655 uint32_t ARMMCCodeEmitter::
656 getThumbBCCTargetOpValue(const MCInst &MI, unsigned OpIdx,
657                          SmallVectorImpl<MCFixup> &Fixups,
658                          const MCSubtargetInfo &STI) const {
659   const MCOperand MO = MI.getOperand(OpIdx);
660   if (MO.isExpr())
661     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_bcc,
662                                     Fixups, STI);
663   return (MO.getImm() >> 1);
664 }
665 
666 /// getThumbCBTargetOpValue - Return encoding info for Thumb branch target.
667 uint32_t ARMMCCodeEmitter::
668 getThumbCBTargetOpValue(const MCInst &MI, unsigned OpIdx,
669                         SmallVectorImpl<MCFixup> &Fixups,
670                         const MCSubtargetInfo &STI) const {
671   const MCOperand MO = MI.getOperand(OpIdx);
672   if (MO.isExpr())
673     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_cb, Fixups, STI);
674   return (MO.getImm() >> 1);
675 }
676 
677 /// Return true if this branch has a non-always predication
678 static bool HasConditionalBranch(const MCInst &MI) {
679   int NumOp = MI.getNumOperands();
680   if (NumOp >= 2) {
681     for (int i = 0; i < NumOp-1; ++i) {
682       const MCOperand &MCOp1 = MI.getOperand(i);
683       const MCOperand &MCOp2 = MI.getOperand(i + 1);
684       if (MCOp1.isImm() && MCOp2.isReg() &&
685           (MCOp2.getReg() == 0 || MCOp2.getReg() == ARM::CPSR)) {
686         if (ARMCC::CondCodes(MCOp1.getImm()) != ARMCC::AL)
687           return true;
688       }
689     }
690   }
691   return false;
692 }
693 
694 /// getBranchTargetOpValue - Return encoding info for 24-bit immediate branch
695 /// target.
696 uint32_t ARMMCCodeEmitter::
697 getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
698                        SmallVectorImpl<MCFixup> &Fixups,
699                        const MCSubtargetInfo &STI) const {
700   // FIXME: This really, really shouldn't use TargetMachine. We don't want
701   // coupling between MC and TM anywhere we can help it.
702   if (isThumb2(STI))
703     return
704       ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_condbranch, Fixups, STI);
705   return getARMBranchTargetOpValue(MI, OpIdx, Fixups, STI);
706 }
707 
708 /// getBranchTargetOpValue - Return encoding info for 24-bit immediate branch
709 /// target.
710 uint32_t ARMMCCodeEmitter::
711 getARMBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
712                           SmallVectorImpl<MCFixup> &Fixups,
713                           const MCSubtargetInfo &STI) const {
714   const MCOperand MO = MI.getOperand(OpIdx);
715   if (MO.isExpr()) {
716     if (HasConditionalBranch(MI))
717       return ::getBranchTargetOpValue(MI, OpIdx,
718                                       ARM::fixup_arm_condbranch, Fixups, STI);
719     return ::getBranchTargetOpValue(MI, OpIdx,
720                                     ARM::fixup_arm_uncondbranch, Fixups, STI);
721   }
722 
723   return MO.getImm() >> 2;
724 }
725 
726 uint32_t ARMMCCodeEmitter::
727 getARMBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
728                           SmallVectorImpl<MCFixup> &Fixups,
729                           const MCSubtargetInfo &STI) const {
730   const MCOperand MO = MI.getOperand(OpIdx);
731   if (MO.isExpr()) {
732     if (HasConditionalBranch(MI))
733       return ::getBranchTargetOpValue(MI, OpIdx,
734                                       ARM::fixup_arm_condbl, Fixups, STI);
735     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_uncondbl, Fixups, STI);
736   }
737 
738   return MO.getImm() >> 2;
739 }
740 
741 uint32_t ARMMCCodeEmitter::
742 getARMBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
743                           SmallVectorImpl<MCFixup> &Fixups,
744                           const MCSubtargetInfo &STI) const {
745   const MCOperand MO = MI.getOperand(OpIdx);
746   if (MO.isExpr())
747     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_blx, Fixups, STI);
748 
749   return MO.getImm() >> 1;
750 }
751 
752 /// getUnconditionalBranchTargetOpValue - Return encoding info for 24-bit
753 /// immediate branch target.
754 uint32_t ARMMCCodeEmitter::getThumbBranchTargetOpValue(
755     const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
756     const MCSubtargetInfo &STI) const {
757   unsigned Val = 0;
758   const MCOperand MO = MI.getOperand(OpIdx);
759 
760   if(MO.isExpr())
761     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_uncondbranch, Fixups, STI);
762   else
763     Val = MO.getImm() >> 1;
764 
765   bool I  = (Val & 0x800000);
766   bool J1 = (Val & 0x400000);
767   bool J2 = (Val & 0x200000);
768   if (I ^ J1)
769     Val &= ~0x400000;
770   else
771     Val |= 0x400000;
772 
773   if (I ^ J2)
774     Val &= ~0x200000;
775   else
776     Val |= 0x200000;
777 
778   return Val;
779 }
780 
781 /// getAdrLabelOpValue - Return encoding info for 12-bit shifted-immediate
782 /// ADR label target.
783 uint32_t ARMMCCodeEmitter::
784 getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
785                    SmallVectorImpl<MCFixup> &Fixups,
786                    const MCSubtargetInfo &STI) const {
787   const MCOperand MO = MI.getOperand(OpIdx);
788   if (MO.isExpr())
789     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_adr_pcrel_12,
790                                     Fixups, STI);
791   int64_t offset = MO.getImm();
792   uint32_t Val = 0x2000;
793 
794   int SoImmVal;
795   if (offset == INT32_MIN) {
796     Val = 0x1000;
797     SoImmVal = 0;
798   } else if (offset < 0) {
799     Val = 0x1000;
800     offset *= -1;
801     SoImmVal = ARM_AM::getSOImmVal(offset);
802     if(SoImmVal == -1) {
803       Val = 0x2000;
804       offset *= -1;
805       SoImmVal = ARM_AM::getSOImmVal(offset);
806     }
807   } else {
808     SoImmVal = ARM_AM::getSOImmVal(offset);
809     if(SoImmVal == -1) {
810       Val = 0x1000;
811       offset *= -1;
812       SoImmVal = ARM_AM::getSOImmVal(offset);
813     }
814   }
815 
816   assert(SoImmVal != -1 && "Not a valid so_imm value!");
817 
818   Val |= SoImmVal;
819   return Val;
820 }
821 
822 /// getT2AdrLabelOpValue - Return encoding info for 12-bit immediate ADR label
823 /// target.
824 uint32_t ARMMCCodeEmitter::
825 getT2AdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
826                    SmallVectorImpl<MCFixup> &Fixups,
827                    const MCSubtargetInfo &STI) const {
828   const MCOperand MO = MI.getOperand(OpIdx);
829   if (MO.isExpr())
830     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_adr_pcrel_12,
831                                     Fixups, STI);
832   int32_t Val = MO.getImm();
833   if (Val == INT32_MIN)
834     Val = 0x1000;
835   else if (Val < 0) {
836     Val *= -1;
837     Val |= 0x1000;
838   }
839   return Val;
840 }
841 
842 /// getThumbAdrLabelOpValue - Return encoding info for 8-bit immediate ADR label
843 /// target.
844 uint32_t ARMMCCodeEmitter::
845 getThumbAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
846                    SmallVectorImpl<MCFixup> &Fixups,
847                    const MCSubtargetInfo &STI) const {
848   const MCOperand MO = MI.getOperand(OpIdx);
849   if (MO.isExpr())
850     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_thumb_adr_pcrel_10,
851                                     Fixups, STI);
852   return MO.getImm();
853 }
854 
855 /// getThumbAddrModeRegRegOpValue - Return encoding info for 'reg + reg'
856 /// operand.
857 uint32_t ARMMCCodeEmitter::
858 getThumbAddrModeRegRegOpValue(const MCInst &MI, unsigned OpIdx,
859                               SmallVectorImpl<MCFixup> &,
860                               const MCSubtargetInfo &STI) const {
861   // [Rn, Rm]
862   //   {5-3} = Rm
863   //   {2-0} = Rn
864   const MCOperand &MO1 = MI.getOperand(OpIdx);
865   const MCOperand &MO2 = MI.getOperand(OpIdx + 1);
866   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
867   unsigned Rm = CTX.getRegisterInfo()->getEncodingValue(MO2.getReg());
868   return (Rm << 3) | Rn;
869 }
870 
871 /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12' operand.
872 uint32_t ARMMCCodeEmitter::
873 getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
874                         SmallVectorImpl<MCFixup> &Fixups,
875                         const MCSubtargetInfo &STI) const {
876   // {17-13} = reg
877   // {12}    = (U)nsigned (add == '1', sub == '0')
878   // {11-0}  = imm12
879   unsigned Reg, Imm12;
880   bool isAdd = true;
881   // If The first operand isn't a register, we have a label reference.
882   const MCOperand &MO = MI.getOperand(OpIdx);
883   if (!MO.isReg()) {
884     Reg = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
885     Imm12 = 0;
886 
887     if (MO.isExpr()) {
888       const MCExpr *Expr = MO.getExpr();
889       isAdd = false ; // 'U' bit is set as part of the fixup.
890 
891       MCFixupKind Kind;
892       if (isThumb2(STI))
893         Kind = MCFixupKind(ARM::fixup_t2_ldst_pcrel_12);
894       else
895         Kind = MCFixupKind(ARM::fixup_arm_ldst_pcrel_12);
896       Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
897 
898       ++MCNumCPRelocations;
899     } else {
900       Reg = ARM::PC;
901       int32_t Offset = MO.getImm();
902       if (Offset == INT32_MIN) {
903         Offset = 0;
904         isAdd = false;
905       } else if (Offset < 0) {
906         Offset *= -1;
907         isAdd = false;
908       }
909       Imm12 = Offset;
910     }
911   } else
912     isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm12, Fixups, STI);
913 
914   uint32_t Binary = Imm12 & 0xfff;
915   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
916   if (isAdd)
917     Binary |= (1 << 12);
918   Binary |= (Reg << 13);
919   return Binary;
920 }
921 
922 /// getT2Imm8s4OpValue - Return encoding info for
923 /// '+/- imm8<<2' operand.
924 uint32_t ARMMCCodeEmitter::
925 getT2Imm8s4OpValue(const MCInst &MI, unsigned OpIdx,
926                    SmallVectorImpl<MCFixup> &Fixups,
927                    const MCSubtargetInfo &STI) const {
928   // FIXME: The immediate operand should have already been encoded like this
929   // before ever getting here. The encoder method should just need to combine
930   // the MI operands for the register and the offset into a single
931   // representation for the complex operand in the .td file. This isn't just
932   // style, unfortunately. As-is, we can't represent the distinct encoding
933   // for #-0.
934 
935   // {8}    = (U)nsigned (add == '1', sub == '0')
936   // {7-0}  = imm8
937   int32_t Imm8 = MI.getOperand(OpIdx).getImm();
938   bool isAdd = Imm8 >= 0;
939 
940   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
941   if (Imm8 < 0)
942     Imm8 = -(uint32_t)Imm8;
943 
944   // Scaled by 4.
945   Imm8 /= 4;
946 
947   uint32_t Binary = Imm8 & 0xff;
948   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
949   if (isAdd)
950     Binary |= (1 << 8);
951   return Binary;
952 }
953 
954 /// getT2AddrModeImm8s4OpValue - Return encoding info for
955 /// 'reg +/- imm8<<2' operand.
956 uint32_t ARMMCCodeEmitter::
957 getT2AddrModeImm8s4OpValue(const MCInst &MI, unsigned OpIdx,
958                         SmallVectorImpl<MCFixup> &Fixups,
959                         const MCSubtargetInfo &STI) const {
960   // {12-9} = reg
961   // {8}    = (U)nsigned (add == '1', sub == '0')
962   // {7-0}  = imm8
963   unsigned Reg, Imm8;
964   bool isAdd = true;
965   // If The first operand isn't a register, we have a label reference.
966   const MCOperand &MO = MI.getOperand(OpIdx);
967   if (!MO.isReg()) {
968     Reg = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
969     Imm8 = 0;
970     isAdd = false ; // 'U' bit is set as part of the fixup.
971 
972     assert(MO.isExpr() && "Unexpected machine operand type!");
973     const MCExpr *Expr = MO.getExpr();
974     MCFixupKind Kind = MCFixupKind(ARM::fixup_t2_pcrel_10);
975     Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
976 
977     ++MCNumCPRelocations;
978   } else
979     isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups, STI);
980 
981   // FIXME: The immediate operand should have already been encoded like this
982   // before ever getting here. The encoder method should just need to combine
983   // the MI operands for the register and the offset into a single
984   // representation for the complex operand in the .td file. This isn't just
985   // style, unfortunately. As-is, we can't represent the distinct encoding
986   // for #-0.
987   uint32_t Binary = (Imm8 >> 2) & 0xff;
988   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
989   if (isAdd)
990     Binary |= (1 << 8);
991   Binary |= (Reg << 9);
992   return Binary;
993 }
994 
995 /// getT2AddrModeImm0_1020s4OpValue - Return encoding info for
996 /// 'reg + imm8<<2' operand.
997 uint32_t ARMMCCodeEmitter::
998 getT2AddrModeImm0_1020s4OpValue(const MCInst &MI, unsigned OpIdx,
999                         SmallVectorImpl<MCFixup> &Fixups,
1000                         const MCSubtargetInfo &STI) const {
1001   // {11-8} = reg
1002   // {7-0}  = imm8
1003   const MCOperand &MO = MI.getOperand(OpIdx);
1004   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1005   unsigned Reg = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1006   unsigned Imm8 = MO1.getImm();
1007   return (Reg << 8) | Imm8;
1008 }
1009 
1010 uint32_t
1011 ARMMCCodeEmitter::getHiLo16ImmOpValue(const MCInst &MI, unsigned OpIdx,
1012                                       SmallVectorImpl<MCFixup> &Fixups,
1013                                       const MCSubtargetInfo &STI) const {
1014   // {20-16} = imm{15-12}
1015   // {11-0}  = imm{11-0}
1016   const MCOperand &MO = MI.getOperand(OpIdx);
1017   if (MO.isImm())
1018     // Hi / lo 16 bits already extracted during earlier passes.
1019     return static_cast<unsigned>(MO.getImm());
1020 
1021   // Handle :upper16: and :lower16: assembly prefixes.
1022   const MCExpr *E = MO.getExpr();
1023   MCFixupKind Kind;
1024   if (E->getKind() == MCExpr::Target) {
1025     const ARMMCExpr *ARM16Expr = cast<ARMMCExpr>(E);
1026     E = ARM16Expr->getSubExpr();
1027 
1028     if (const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(E)) {
1029       const int64_t Value = MCE->getValue();
1030       if (Value > UINT32_MAX)
1031         report_fatal_error("constant value truncated (limited to 32-bit)");
1032 
1033       switch (ARM16Expr->getKind()) {
1034       case ARMMCExpr::VK_ARM_HI16:
1035         return (int32_t(Value) & 0xffff0000) >> 16;
1036       case ARMMCExpr::VK_ARM_LO16:
1037         return (int32_t(Value) & 0x0000ffff);
1038       default: llvm_unreachable("Unsupported ARMFixup");
1039       }
1040     }
1041 
1042     switch (ARM16Expr->getKind()) {
1043     default: llvm_unreachable("Unsupported ARMFixup");
1044     case ARMMCExpr::VK_ARM_HI16:
1045       Kind = MCFixupKind(isThumb(STI) ? ARM::fixup_t2_movt_hi16
1046                                       : ARM::fixup_arm_movt_hi16);
1047       break;
1048     case ARMMCExpr::VK_ARM_LO16:
1049       Kind = MCFixupKind(isThumb(STI) ? ARM::fixup_t2_movw_lo16
1050                                       : ARM::fixup_arm_movw_lo16);
1051       break;
1052     }
1053 
1054     Fixups.push_back(MCFixup::create(0, E, Kind, MI.getLoc()));
1055     return 0;
1056   }
1057   // If the expression doesn't have :upper16: or :lower16: on it,
1058   // it's just a plain immediate expression, previously those evaluated to
1059   // the lower 16 bits of the expression regardless of whether
1060   // we have a movt or a movw, but that led to misleadingly results.
1061   // This is disallowed in the AsmParser in validateInstruction()
1062   // so this should never happen.
1063   llvm_unreachable("expression without :upper16: or :lower16:");
1064 }
1065 
1066 uint32_t ARMMCCodeEmitter::
1067 getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
1068                     SmallVectorImpl<MCFixup> &Fixups,
1069                     const MCSubtargetInfo &STI) const {
1070   const MCOperand &MO = MI.getOperand(OpIdx);
1071   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1072   const MCOperand &MO2 = MI.getOperand(OpIdx+2);
1073   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1074   unsigned Rm = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1075   unsigned ShImm = ARM_AM::getAM2Offset(MO2.getImm());
1076   bool isAdd = ARM_AM::getAM2Op(MO2.getImm()) == ARM_AM::add;
1077   ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(MO2.getImm());
1078   unsigned SBits = getShiftOp(ShOp);
1079 
1080   // While "lsr #32" and "asr #32" exist, they are encoded with a 0 in the shift
1081   // amount. However, it would be an easy mistake to make so check here.
1082   assert((ShImm & ~0x1f) == 0 && "Out of range shift amount");
1083 
1084   // {16-13} = Rn
1085   // {12}    = isAdd
1086   // {11-0}  = shifter
1087   //  {3-0}  = Rm
1088   //  {4}    = 0
1089   //  {6-5}  = type
1090   //  {11-7} = imm
1091   uint32_t Binary = Rm;
1092   Binary |= Rn << 13;
1093   Binary |= SBits << 5;
1094   Binary |= ShImm << 7;
1095   if (isAdd)
1096     Binary |= 1 << 12;
1097   return Binary;
1098 }
1099 
1100 uint32_t ARMMCCodeEmitter::
1101 getAddrMode2OffsetOpValue(const MCInst &MI, unsigned OpIdx,
1102                           SmallVectorImpl<MCFixup> &Fixups,
1103                           const MCSubtargetInfo &STI) const {
1104   // {13}     1 == imm12, 0 == Rm
1105   // {12}     isAdd
1106   // {11-0}   imm12/Rm
1107   const MCOperand &MO = MI.getOperand(OpIdx);
1108   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1109   unsigned Imm = MO1.getImm();
1110   bool isAdd = ARM_AM::getAM2Op(Imm) == ARM_AM::add;
1111   bool isReg = MO.getReg() != 0;
1112   uint32_t Binary = ARM_AM::getAM2Offset(Imm);
1113   // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm12
1114   if (isReg) {
1115     ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(Imm);
1116     Binary <<= 7;                    // Shift amount is bits [11:7]
1117     Binary |= getShiftOp(ShOp) << 5; // Shift type is bits [6:5]
1118     Binary |= CTX.getRegisterInfo()->getEncodingValue(MO.getReg()); // Rm is bits [3:0]
1119   }
1120   return Binary | (isAdd << 12) | (isReg << 13);
1121 }
1122 
1123 uint32_t ARMMCCodeEmitter::
1124 getPostIdxRegOpValue(const MCInst &MI, unsigned OpIdx,
1125                      SmallVectorImpl<MCFixup> &Fixups,
1126                      const MCSubtargetInfo &STI) const {
1127   // {4}      isAdd
1128   // {3-0}    Rm
1129   const MCOperand &MO = MI.getOperand(OpIdx);
1130   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1131   bool isAdd = MO1.getImm() != 0;
1132   return CTX.getRegisterInfo()->getEncodingValue(MO.getReg()) | (isAdd << 4);
1133 }
1134 
1135 uint32_t ARMMCCodeEmitter::
1136 getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
1137                           SmallVectorImpl<MCFixup> &Fixups,
1138                           const MCSubtargetInfo &STI) const {
1139   // {9}      1 == imm8, 0 == Rm
1140   // {8}      isAdd
1141   // {7-4}    imm7_4/zero
1142   // {3-0}    imm3_0/Rm
1143   const MCOperand &MO = MI.getOperand(OpIdx);
1144   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1145   unsigned Imm = MO1.getImm();
1146   bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
1147   bool isImm = MO.getReg() == 0;
1148   uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
1149   // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
1150   if (!isImm)
1151     Imm8 = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1152   return Imm8 | (isAdd << 8) | (isImm << 9);
1153 }
1154 
1155 uint32_t ARMMCCodeEmitter::
1156 getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
1157                     SmallVectorImpl<MCFixup> &Fixups,
1158                     const MCSubtargetInfo &STI) const {
1159   // {13}     1 == imm8, 0 == Rm
1160   // {12-9}   Rn
1161   // {8}      isAdd
1162   // {7-4}    imm7_4/zero
1163   // {3-0}    imm3_0/Rm
1164   const MCOperand &MO = MI.getOperand(OpIdx);
1165   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1166   const MCOperand &MO2 = MI.getOperand(OpIdx+2);
1167 
1168   // If The first operand isn't a register, we have a label reference.
1169   if (!MO.isReg()) {
1170     unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
1171 
1172     assert(MO.isExpr() && "Unexpected machine operand type!");
1173     const MCExpr *Expr = MO.getExpr();
1174     MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_pcrel_10_unscaled);
1175     Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
1176 
1177     ++MCNumCPRelocations;
1178     return (Rn << 9) | (1 << 13);
1179   }
1180   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1181   unsigned Imm = MO2.getImm();
1182   bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
1183   bool isImm = MO1.getReg() == 0;
1184   uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
1185   // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
1186   if (!isImm)
1187     Imm8 = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1188   return (Rn << 9) | Imm8 | (isAdd << 8) | (isImm << 13);
1189 }
1190 
1191 /// getAddrModeThumbSPOpValue - Encode the t_addrmode_sp operands.
1192 uint32_t ARMMCCodeEmitter::
1193 getAddrModeThumbSPOpValue(const MCInst &MI, unsigned OpIdx,
1194                           SmallVectorImpl<MCFixup> &Fixups,
1195                           const MCSubtargetInfo &STI) const {
1196   // [SP, #imm]
1197   //   {7-0} = imm8
1198   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1199   assert(MI.getOperand(OpIdx).getReg() == ARM::SP &&
1200          "Unexpected base register!");
1201 
1202   // The immediate is already shifted for the implicit zeroes, so no change
1203   // here.
1204   return MO1.getImm() & 0xff;
1205 }
1206 
1207 /// getAddrModeISOpValue - Encode the t_addrmode_is# operands.
1208 uint32_t ARMMCCodeEmitter::
1209 getAddrModeISOpValue(const MCInst &MI, unsigned OpIdx,
1210                      SmallVectorImpl<MCFixup> &Fixups,
1211                      const MCSubtargetInfo &STI) const {
1212   // [Rn, #imm]
1213   //   {7-3} = imm5
1214   //   {2-0} = Rn
1215   const MCOperand &MO = MI.getOperand(OpIdx);
1216   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1217   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1218   unsigned Imm5 = MO1.getImm();
1219   return ((Imm5 & 0x1f) << 3) | Rn;
1220 }
1221 
1222 /// getAddrModePCOpValue - Return encoding for t_addrmode_pc operands.
1223 uint32_t ARMMCCodeEmitter::
1224 getAddrModePCOpValue(const MCInst &MI, unsigned OpIdx,
1225                      SmallVectorImpl<MCFixup> &Fixups,
1226                      const MCSubtargetInfo &STI) const {
1227   const MCOperand MO = MI.getOperand(OpIdx);
1228   if (MO.isExpr())
1229     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_cp, Fixups, STI);
1230   return (MO.getImm() >> 2);
1231 }
1232 
1233 /// getAddrMode5OpValue - Return encoding info for 'reg +/- (imm8 << 2)' operand.
1234 uint32_t ARMMCCodeEmitter::
1235 getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
1236                     SmallVectorImpl<MCFixup> &Fixups,
1237                     const MCSubtargetInfo &STI) const {
1238   // {12-9} = reg
1239   // {8}    = (U)nsigned (add == '1', sub == '0')
1240   // {7-0}  = imm8
1241   unsigned Reg, Imm8;
1242   bool isAdd;
1243   // If The first operand isn't a register, we have a label reference.
1244   const MCOperand &MO = MI.getOperand(OpIdx);
1245   if (!MO.isReg()) {
1246     Reg = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
1247     Imm8 = 0;
1248     isAdd = false; // 'U' bit is handled as part of the fixup.
1249 
1250     assert(MO.isExpr() && "Unexpected machine operand type!");
1251     const MCExpr *Expr = MO.getExpr();
1252     MCFixupKind Kind;
1253     if (isThumb2(STI))
1254       Kind = MCFixupKind(ARM::fixup_t2_pcrel_10);
1255     else
1256       Kind = MCFixupKind(ARM::fixup_arm_pcrel_10);
1257     Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
1258 
1259     ++MCNumCPRelocations;
1260   } else {
1261     EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups, STI);
1262     isAdd = ARM_AM::getAM5Op(Imm8) == ARM_AM::add;
1263   }
1264 
1265   uint32_t Binary = ARM_AM::getAM5Offset(Imm8);
1266   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
1267   if (isAdd)
1268     Binary |= (1 << 8);
1269   Binary |= (Reg << 9);
1270   return Binary;
1271 }
1272 
1273 /// getAddrMode5FP16OpValue - Return encoding info for 'reg +/- (imm8 << 1)' operand.
1274 uint32_t ARMMCCodeEmitter::
1275 getAddrMode5FP16OpValue(const MCInst &MI, unsigned OpIdx,
1276                     SmallVectorImpl<MCFixup> &Fixups,
1277                     const MCSubtargetInfo &STI) const {
1278   // {12-9} = reg
1279   // {8}    = (U)nsigned (add == '1', sub == '0')
1280   // {7-0}  = imm8
1281   unsigned Reg, Imm8;
1282   bool isAdd;
1283   // If The first operand isn't a register, we have a label reference.
1284   const MCOperand &MO = MI.getOperand(OpIdx);
1285   if (!MO.isReg()) {
1286     Reg = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
1287     Imm8 = 0;
1288     isAdd = false; // 'U' bit is handled as part of the fixup.
1289 
1290     assert(MO.isExpr() && "Unexpected machine operand type!");
1291     const MCExpr *Expr = MO.getExpr();
1292     MCFixupKind Kind;
1293     if (isThumb2(STI))
1294       Kind = MCFixupKind(ARM::fixup_t2_pcrel_9);
1295     else
1296       Kind = MCFixupKind(ARM::fixup_arm_pcrel_9);
1297     Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
1298 
1299     ++MCNumCPRelocations;
1300   } else {
1301     EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups, STI);
1302     isAdd = ARM_AM::getAM5Op(Imm8) == ARM_AM::add;
1303   }
1304 
1305   uint32_t Binary = ARM_AM::getAM5Offset(Imm8);
1306   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
1307   if (isAdd)
1308     Binary |= (1 << 8);
1309   Binary |= (Reg << 9);
1310   return Binary;
1311 }
1312 
1313 unsigned ARMMCCodeEmitter::
1314 getSORegRegOpValue(const MCInst &MI, unsigned OpIdx,
1315                 SmallVectorImpl<MCFixup> &Fixups,
1316                 const MCSubtargetInfo &STI) const {
1317   // Sub-operands are [reg, reg, imm]. The first register is Rm, the reg to be
1318   // shifted. The second is Rs, the amount to shift by, and the third specifies
1319   // the type of the shift.
1320   //
1321   // {3-0} = Rm.
1322   // {4}   = 1
1323   // {6-5} = type
1324   // {11-8} = Rs
1325   // {7}    = 0
1326 
1327   const MCOperand &MO  = MI.getOperand(OpIdx);
1328   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1329   const MCOperand &MO2 = MI.getOperand(OpIdx + 2);
1330   ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO2.getImm());
1331 
1332   // Encode Rm.
1333   unsigned Binary = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1334 
1335   // Encode the shift opcode.
1336   unsigned SBits = 0;
1337   unsigned Rs = MO1.getReg();
1338   if (Rs) {
1339     // Set shift operand (bit[7:4]).
1340     // LSL - 0001
1341     // LSR - 0011
1342     // ASR - 0101
1343     // ROR - 0111
1344     switch (SOpc) {
1345     default: llvm_unreachable("Unknown shift opc!");
1346     case ARM_AM::lsl: SBits = 0x1; break;
1347     case ARM_AM::lsr: SBits = 0x3; break;
1348     case ARM_AM::asr: SBits = 0x5; break;
1349     case ARM_AM::ror: SBits = 0x7; break;
1350     }
1351   }
1352 
1353   Binary |= SBits << 4;
1354 
1355   // Encode the shift operation Rs.
1356   // Encode Rs bit[11:8].
1357   assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
1358   return Binary | (CTX.getRegisterInfo()->getEncodingValue(Rs) << ARMII::RegRsShift);
1359 }
1360 
1361 unsigned ARMMCCodeEmitter::
1362 getSORegImmOpValue(const MCInst &MI, unsigned OpIdx,
1363                 SmallVectorImpl<MCFixup> &Fixups,
1364                 const MCSubtargetInfo &STI) const {
1365   // Sub-operands are [reg, imm]. The first register is Rm, the reg to be
1366   // shifted. The second is the amount to shift by.
1367   //
1368   // {3-0} = Rm.
1369   // {4}   = 0
1370   // {6-5} = type
1371   // {11-7} = imm
1372 
1373   const MCOperand &MO  = MI.getOperand(OpIdx);
1374   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1375   ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO1.getImm());
1376 
1377   // Encode Rm.
1378   unsigned Binary = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1379 
1380   // Encode the shift opcode.
1381   unsigned SBits = 0;
1382 
1383   // Set shift operand (bit[6:4]).
1384   // LSL - 000
1385   // LSR - 010
1386   // ASR - 100
1387   // ROR - 110
1388   // RRX - 110 and bit[11:8] clear.
1389   switch (SOpc) {
1390   default: llvm_unreachable("Unknown shift opc!");
1391   case ARM_AM::lsl: SBits = 0x0; break;
1392   case ARM_AM::lsr: SBits = 0x2; break;
1393   case ARM_AM::asr: SBits = 0x4; break;
1394   case ARM_AM::ror: SBits = 0x6; break;
1395   case ARM_AM::rrx:
1396     Binary |= 0x60;
1397     return Binary;
1398   }
1399 
1400   // Encode shift_imm bit[11:7].
1401   Binary |= SBits << 4;
1402   unsigned Offset = ARM_AM::getSORegOffset(MO1.getImm());
1403   assert(Offset < 32 && "Offset must be in range 0-31!");
1404   return Binary | (Offset << 7);
1405 }
1406 
1407 
1408 unsigned ARMMCCodeEmitter::
1409 getT2AddrModeSORegOpValue(const MCInst &MI, unsigned OpNum,
1410                 SmallVectorImpl<MCFixup> &Fixups,
1411                 const MCSubtargetInfo &STI) const {
1412   const MCOperand &MO1 = MI.getOperand(OpNum);
1413   const MCOperand &MO2 = MI.getOperand(OpNum+1);
1414   const MCOperand &MO3 = MI.getOperand(OpNum+2);
1415 
1416   // Encoded as [Rn, Rm, imm].
1417   // FIXME: Needs fixup support.
1418   unsigned Value = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1419   Value <<= 4;
1420   Value |= CTX.getRegisterInfo()->getEncodingValue(MO2.getReg());
1421   Value <<= 2;
1422   Value |= MO3.getImm();
1423 
1424   return Value;
1425 }
1426 
1427 unsigned ARMMCCodeEmitter::
1428 getT2AddrModeImm8OpValue(const MCInst &MI, unsigned OpNum,
1429                          SmallVectorImpl<MCFixup> &Fixups,
1430                          const MCSubtargetInfo &STI) const {
1431   const MCOperand &MO1 = MI.getOperand(OpNum);
1432   const MCOperand &MO2 = MI.getOperand(OpNum+1);
1433 
1434   // FIXME: Needs fixup support.
1435   unsigned Value = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1436 
1437   // Even though the immediate is 8 bits long, we need 9 bits in order
1438   // to represent the (inverse of the) sign bit.
1439   Value <<= 9;
1440   int32_t tmp = (int32_t)MO2.getImm();
1441   if (tmp < 0)
1442     tmp = abs(tmp);
1443   else
1444     Value |= 256; // Set the ADD bit
1445   Value |= tmp & 255;
1446   return Value;
1447 }
1448 
1449 unsigned ARMMCCodeEmitter::
1450 getT2AddrModeImm8OffsetOpValue(const MCInst &MI, unsigned OpNum,
1451                          SmallVectorImpl<MCFixup> &Fixups,
1452                          const MCSubtargetInfo &STI) const {
1453   const MCOperand &MO1 = MI.getOperand(OpNum);
1454 
1455   // FIXME: Needs fixup support.
1456   unsigned Value = 0;
1457   int32_t tmp = (int32_t)MO1.getImm();
1458   if (tmp < 0)
1459     tmp = abs(tmp);
1460   else
1461     Value |= 256; // Set the ADD bit
1462   Value |= tmp & 255;
1463   return Value;
1464 }
1465 
1466 unsigned ARMMCCodeEmitter::
1467 getT2SORegOpValue(const MCInst &MI, unsigned OpIdx,
1468                 SmallVectorImpl<MCFixup> &Fixups,
1469                 const MCSubtargetInfo &STI) const {
1470   // Sub-operands are [reg, imm]. The first register is Rm, the reg to be
1471   // shifted. The second is the amount to shift by.
1472   //
1473   // {3-0} = Rm.
1474   // {4}   = 0
1475   // {6-5} = type
1476   // {11-7} = imm
1477 
1478   const MCOperand &MO  = MI.getOperand(OpIdx);
1479   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1480   ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO1.getImm());
1481 
1482   // Encode Rm.
1483   unsigned Binary = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1484 
1485   // Encode the shift opcode.
1486   unsigned SBits = 0;
1487   // Set shift operand (bit[6:4]).
1488   // LSL - 000
1489   // LSR - 010
1490   // ASR - 100
1491   // ROR - 110
1492   switch (SOpc) {
1493   default: llvm_unreachable("Unknown shift opc!");
1494   case ARM_AM::lsl: SBits = 0x0; break;
1495   case ARM_AM::lsr: SBits = 0x2; break;
1496   case ARM_AM::asr: SBits = 0x4; break;
1497   case ARM_AM::rrx: LLVM_FALLTHROUGH;
1498   case ARM_AM::ror: SBits = 0x6; break;
1499   }
1500 
1501   Binary |= SBits << 4;
1502   if (SOpc == ARM_AM::rrx)
1503     return Binary;
1504 
1505   // Encode shift_imm bit[11:7].
1506   return Binary | ARM_AM::getSORegOffset(MO1.getImm()) << 7;
1507 }
1508 
1509 unsigned ARMMCCodeEmitter::
1510 getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
1511                                SmallVectorImpl<MCFixup> &Fixups,
1512                                const MCSubtargetInfo &STI) const {
1513   // 10 bits. lower 5 bits are are the lsb of the mask, high five bits are the
1514   // msb of the mask.
1515   const MCOperand &MO = MI.getOperand(Op);
1516   uint32_t v = ~MO.getImm();
1517   uint32_t lsb = countTrailingZeros(v);
1518   uint32_t msb = (32 - countLeadingZeros (v)) - 1;
1519   assert(v != 0 && lsb < 32 && msb < 32 && "Illegal bitfield mask!");
1520   return lsb | (msb << 5);
1521 }
1522 
1523 unsigned ARMMCCodeEmitter::
1524 getRegisterListOpValue(const MCInst &MI, unsigned Op,
1525                        SmallVectorImpl<MCFixup> &Fixups,
1526                        const MCSubtargetInfo &STI) const {
1527   // VLDM/VSTM:
1528   //   {12-8} = Vd
1529   //   {7-0}  = Number of registers
1530   //
1531   // LDM/STM:
1532   //   {15-0}  = Bitfield of GPRs.
1533   unsigned Reg = MI.getOperand(Op).getReg();
1534   bool SPRRegs = ARMMCRegisterClasses[ARM::SPRRegClassID].contains(Reg);
1535   bool DPRRegs = ARMMCRegisterClasses[ARM::DPRRegClassID].contains(Reg);
1536 
1537   unsigned Binary = 0;
1538 
1539   if (SPRRegs || DPRRegs) {
1540     // VLDM/VSTM
1541     unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg);
1542     unsigned NumRegs = (MI.getNumOperands() - Op) & 0xff;
1543     Binary |= (RegNo & 0x1f) << 8;
1544     if (SPRRegs)
1545       Binary |= NumRegs;
1546     else
1547       Binary |= NumRegs * 2;
1548   } else {
1549     const MCRegisterInfo &MRI = *CTX.getRegisterInfo();
1550     assert(std::is_sorted(MI.begin() + Op, MI.end(),
1551                           [&](const MCOperand &LHS, const MCOperand &RHS) {
1552                             return MRI.getEncodingValue(LHS.getReg()) <
1553                                    MRI.getEncodingValue(RHS.getReg());
1554                           }));
1555 
1556     for (unsigned I = Op, E = MI.getNumOperands(); I < E; ++I) {
1557       unsigned RegNo = MRI.getEncodingValue(MI.getOperand(I).getReg());
1558       Binary |= 1 << RegNo;
1559     }
1560   }
1561 
1562   return Binary;
1563 }
1564 
1565 /// getAddrMode6AddressOpValue - Encode an addrmode6 register number along
1566 /// with the alignment operand.
1567 unsigned ARMMCCodeEmitter::
1568 getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
1569                            SmallVectorImpl<MCFixup> &Fixups,
1570                            const MCSubtargetInfo &STI) const {
1571   const MCOperand &Reg = MI.getOperand(Op);
1572   const MCOperand &Imm = MI.getOperand(Op + 1);
1573 
1574   unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg.getReg());
1575   unsigned Align = 0;
1576 
1577   switch (Imm.getImm()) {
1578   default: break;
1579   case 2:
1580   case 4:
1581   case 8:  Align = 0x01; break;
1582   case 16: Align = 0x02; break;
1583   case 32: Align = 0x03; break;
1584   }
1585 
1586   return RegNo | (Align << 4);
1587 }
1588 
1589 /// getAddrMode6OneLane32AddressOpValue - Encode an addrmode6 register number
1590 /// along  with the alignment operand for use in VST1 and VLD1 with size 32.
1591 unsigned ARMMCCodeEmitter::
1592 getAddrMode6OneLane32AddressOpValue(const MCInst &MI, unsigned Op,
1593                                     SmallVectorImpl<MCFixup> &Fixups,
1594                                     const MCSubtargetInfo &STI) const {
1595   const MCOperand &Reg = MI.getOperand(Op);
1596   const MCOperand &Imm = MI.getOperand(Op + 1);
1597 
1598   unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg.getReg());
1599   unsigned Align = 0;
1600 
1601   switch (Imm.getImm()) {
1602   default: break;
1603   case 8:
1604   case 16:
1605   case 32: // Default '0' value for invalid alignments of 8, 16, 32 bytes.
1606   case 2: Align = 0x00; break;
1607   case 4: Align = 0x03; break;
1608   }
1609 
1610   return RegNo | (Align << 4);
1611 }
1612 
1613 
1614 /// getAddrMode6DupAddressOpValue - Encode an addrmode6 register number and
1615 /// alignment operand for use in VLD-dup instructions.  This is the same as
1616 /// getAddrMode6AddressOpValue except for the alignment encoding, which is
1617 /// different for VLD4-dup.
1618 unsigned ARMMCCodeEmitter::
1619 getAddrMode6DupAddressOpValue(const MCInst &MI, unsigned Op,
1620                               SmallVectorImpl<MCFixup> &Fixups,
1621                               const MCSubtargetInfo &STI) const {
1622   const MCOperand &Reg = MI.getOperand(Op);
1623   const MCOperand &Imm = MI.getOperand(Op + 1);
1624 
1625   unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg.getReg());
1626   unsigned Align = 0;
1627 
1628   switch (Imm.getImm()) {
1629   default: break;
1630   case 2:
1631   case 4:
1632   case 8:  Align = 0x01; break;
1633   case 16: Align = 0x03; break;
1634   }
1635 
1636   return RegNo | (Align << 4);
1637 }
1638 
1639 unsigned ARMMCCodeEmitter::
1640 getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
1641                           SmallVectorImpl<MCFixup> &Fixups,
1642                           const MCSubtargetInfo &STI) const {
1643   const MCOperand &MO = MI.getOperand(Op);
1644   if (MO.getReg() == 0) return 0x0D;
1645   return CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1646 }
1647 
1648 unsigned ARMMCCodeEmitter::
1649 getShiftRight8Imm(const MCInst &MI, unsigned Op,
1650                   SmallVectorImpl<MCFixup> &Fixups,
1651                   const MCSubtargetInfo &STI) const {
1652   return 8 - MI.getOperand(Op).getImm();
1653 }
1654 
1655 unsigned ARMMCCodeEmitter::
1656 getShiftRight16Imm(const MCInst &MI, unsigned Op,
1657                    SmallVectorImpl<MCFixup> &Fixups,
1658                    const MCSubtargetInfo &STI) const {
1659   return 16 - MI.getOperand(Op).getImm();
1660 }
1661 
1662 unsigned ARMMCCodeEmitter::
1663 getShiftRight32Imm(const MCInst &MI, unsigned Op,
1664                    SmallVectorImpl<MCFixup> &Fixups,
1665                    const MCSubtargetInfo &STI) const {
1666   return 32 - MI.getOperand(Op).getImm();
1667 }
1668 
1669 unsigned ARMMCCodeEmitter::
1670 getShiftRight64Imm(const MCInst &MI, unsigned Op,
1671                    SmallVectorImpl<MCFixup> &Fixups,
1672                    const MCSubtargetInfo &STI) const {
1673   return 64 - MI.getOperand(Op).getImm();
1674 }
1675 
1676 void ARMMCCodeEmitter::
1677 encodeInstruction(const MCInst &MI, raw_ostream &OS,
1678                   SmallVectorImpl<MCFixup> &Fixups,
1679                   const MCSubtargetInfo &STI) const {
1680   // Pseudo instructions don't get encoded.
1681   const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
1682   uint64_t TSFlags = Desc.TSFlags;
1683   if ((TSFlags & ARMII::FormMask) == ARMII::Pseudo)
1684     return;
1685 
1686   int Size;
1687   if (Desc.getSize() == 2 || Desc.getSize() == 4)
1688     Size = Desc.getSize();
1689   else
1690     llvm_unreachable("Unexpected instruction size!");
1691 
1692   uint32_t Binary = getBinaryCodeForInstr(MI, Fixups, STI);
1693   // Thumb 32-bit wide instructions need to emit the high order halfword
1694   // first.
1695   if (isThumb(STI) && Size == 4) {
1696     EmitConstant(Binary >> 16, 2, OS);
1697     EmitConstant(Binary & 0xffff, 2, OS);
1698   } else
1699     EmitConstant(Binary, Size, OS);
1700   ++MCNumEmitted;  // Keep track of the # of mi's emitted.
1701 }
1702 
1703 #include "ARMGenMCCodeEmitter.inc"
1704 
1705 MCCodeEmitter *llvm::createARMLEMCCodeEmitter(const MCInstrInfo &MCII,
1706                                               const MCRegisterInfo &MRI,
1707                                               MCContext &Ctx) {
1708   return new ARMMCCodeEmitter(MCII, Ctx, true);
1709 }
1710 
1711 MCCodeEmitter *llvm::createARMBEMCCodeEmitter(const MCInstrInfo &MCII,
1712                                               const MCRegisterInfo &MRI,
1713                                               MCContext &Ctx) {
1714   return new ARMMCCodeEmitter(MCII, Ctx, false);
1715 }
1716