xref: /freebsd/contrib/llvm-project/llvm/lib/Target/ARM/MCTargetDesc/ARMMCCodeEmitter.cpp (revision 5f757f3ff9144b609b3c433dfd370cc6bdc191ad)
1 //===-- ARM/ARMMCCodeEmitter.cpp - Convert ARM code to machine code -------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the ARMMCCodeEmitter class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "MCTargetDesc/ARMAddressingModes.h"
14 #include "MCTargetDesc/ARMBaseInfo.h"
15 #include "MCTargetDesc/ARMFixupKinds.h"
16 #include "MCTargetDesc/ARMMCExpr.h"
17 #include "llvm/ADT/APFloat.h"
18 #include "llvm/ADT/APInt.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/Statistic.h"
21 #include "llvm/MC/MCCodeEmitter.h"
22 #include "llvm/MC/MCContext.h"
23 #include "llvm/MC/MCExpr.h"
24 #include "llvm/MC/MCFixup.h"
25 #include "llvm/MC/MCInst.h"
26 #include "llvm/MC/MCInstrDesc.h"
27 #include "llvm/MC/MCInstrInfo.h"
28 #include "llvm/MC/MCRegisterInfo.h"
29 #include "llvm/MC/MCSubtargetInfo.h"
30 #include "llvm/Support/Casting.h"
31 #include "llvm/Support/Compiler.h"
32 #include "llvm/Support/EndianStream.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/MathExtras.h"
35 #include "llvm/Support/raw_ostream.h"
36 #include "llvm/TargetParser/Triple.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   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.hasFeature(ARM::ModeThumb);
66   }
67 
68   bool isThumb2(const MCSubtargetInfo &STI) const {
69     return isThumb(STI) && STI.hasFeature(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   /// getHiLoImmOpValue - Return the encoding for either the hi / low 16-bit, or
92   /// high/middle-high/middle-low/low 8 bits of the specified operand. This is
93   /// used for operands with :lower16:, :upper16: :lower0_7:, :lower8_15:,
94   /// :higher0_7:, and :higher8_15: prefixes.
95   uint32_t getHiLoImmOpValue(const MCInst &MI, unsigned OpIdx,
96                              SmallVectorImpl<MCFixup> &Fixups,
97                              const MCSubtargetInfo &STI) const;
98 
99   bool EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx,
100                               unsigned &Reg, unsigned &Imm,
101                               SmallVectorImpl<MCFixup> &Fixups,
102                               const MCSubtargetInfo &STI) const;
103 
104   /// getThumbBLTargetOpValue - Return encoding info for Thumb immediate
105   /// BL branch target.
106   uint32_t getThumbBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
107                                    SmallVectorImpl<MCFixup> &Fixups,
108                                    const MCSubtargetInfo &STI) const;
109 
110   /// getThumbBLXTargetOpValue - Return encoding info for Thumb immediate
111   /// BLX branch target.
112   uint32_t getThumbBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
113                                     SmallVectorImpl<MCFixup> &Fixups,
114                                     const MCSubtargetInfo &STI) const;
115 
116   /// getThumbBRTargetOpValue - Return encoding info for Thumb branch target.
117   uint32_t getThumbBRTargetOpValue(const MCInst &MI, unsigned OpIdx,
118                                    SmallVectorImpl<MCFixup> &Fixups,
119                                    const MCSubtargetInfo &STI) const;
120 
121   /// getThumbBCCTargetOpValue - Return encoding info for Thumb branch target.
122   uint32_t getThumbBCCTargetOpValue(const MCInst &MI, unsigned OpIdx,
123                                     SmallVectorImpl<MCFixup> &Fixups,
124                                     const MCSubtargetInfo &STI) const;
125 
126   /// getThumbCBTargetOpValue - Return encoding info for Thumb branch target.
127   uint32_t getThumbCBTargetOpValue(const MCInst &MI, unsigned OpIdx,
128                                    SmallVectorImpl<MCFixup> &Fixups,
129                                    const MCSubtargetInfo &STI) const;
130 
131   /// getBranchTargetOpValue - Return encoding info for 24-bit immediate
132   /// branch target.
133   uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
134                                   SmallVectorImpl<MCFixup> &Fixups,
135                                   const MCSubtargetInfo &STI) const;
136 
137   /// getThumbBranchTargetOpValue - Return encoding info for 24-bit
138   /// immediate Thumb2 direct branch target.
139   uint32_t getThumbBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
140                                        SmallVectorImpl<MCFixup> &Fixups,
141                                        const MCSubtargetInfo &STI) const;
142 
143   /// getARMBranchTargetOpValue - Return encoding info for 24-bit immediate
144   /// branch target.
145   uint32_t getARMBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
146                                      SmallVectorImpl<MCFixup> &Fixups,
147                                      const MCSubtargetInfo &STI) const;
148   uint32_t getARMBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
149                                  SmallVectorImpl<MCFixup> &Fixups,
150                                  const MCSubtargetInfo &STI) const;
151   uint32_t getARMBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
152                                   SmallVectorImpl<MCFixup> &Fixups,
153                                   const MCSubtargetInfo &STI) const;
154 
155   /// getAdrLabelOpValue - Return encoding info for 12-bit immediate
156   /// ADR label target.
157   uint32_t getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
158                               SmallVectorImpl<MCFixup> &Fixups,
159                               const MCSubtargetInfo &STI) const;
160   uint32_t getThumbAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
161                               SmallVectorImpl<MCFixup> &Fixups,
162                               const MCSubtargetInfo &STI) const;
163   uint32_t getT2AdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
164                               SmallVectorImpl<MCFixup> &Fixups,
165                               const MCSubtargetInfo &STI) const;
166 
167   uint32_t getITMaskOpValue(const MCInst &MI, unsigned OpIdx,
168                             SmallVectorImpl<MCFixup> &Fixups,
169                             const MCSubtargetInfo &STI) const;
170 
171   /// getMVEShiftImmOpValue - Return encoding info for the 'sz:imm5'
172   /// operand.
173   uint32_t getMVEShiftImmOpValue(const MCInst &MI, unsigned OpIdx,
174                                  SmallVectorImpl<MCFixup> &Fixups,
175                                  const MCSubtargetInfo &STI) const;
176 
177   /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12'
178   /// operand.
179   uint32_t getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
180                                    SmallVectorImpl<MCFixup> &Fixups,
181                                    const MCSubtargetInfo &STI) const;
182 
183   /// getThumbAddrModeRegRegOpValue - Return encoding for 'reg + reg' operand.
184   uint32_t getThumbAddrModeRegRegOpValue(const MCInst &MI, unsigned OpIdx,
185                                          SmallVectorImpl<MCFixup> &Fixups,
186                                          const MCSubtargetInfo &STI) const;
187 
188   /// getT2AddrModeImm8s4OpValue - Return encoding info for 'reg +/- imm8<<2'
189   /// operand.
190   uint32_t getT2AddrModeImm8s4OpValue(const MCInst &MI, unsigned OpIdx,
191                                    SmallVectorImpl<MCFixup> &Fixups,
192                                    const MCSubtargetInfo &STI) const;
193 
194   /// getT2AddrModeImm7s4OpValue - Return encoding info for 'reg +/- imm7<<2'
195   /// operand.
196   uint32_t getT2AddrModeImm7s4OpValue(const MCInst &MI, unsigned OpIdx,
197                                       SmallVectorImpl<MCFixup> &Fixups,
198                                       const MCSubtargetInfo &STI) const;
199 
200   /// getT2AddrModeImm0_1020s4OpValue - Return encoding info for 'reg + imm8<<2'
201   /// operand.
202   uint32_t getT2AddrModeImm0_1020s4OpValue(const MCInst &MI, unsigned OpIdx,
203                                    SmallVectorImpl<MCFixup> &Fixups,
204                                    const MCSubtargetInfo &STI) const;
205 
206   /// getT2ScaledImmOpValue - Return encoding info for '+/- immX<<Y'
207   /// operand.
208   template<unsigned Bits, unsigned Shift>
209   uint32_t getT2ScaledImmOpValue(const MCInst &MI, unsigned OpIdx,
210                                  SmallVectorImpl<MCFixup> &Fixups,
211                                  const MCSubtargetInfo &STI) const;
212 
213   /// getMveAddrModeRQOpValue - Return encoding info for 'reg, vreg'
214   /// operand.
215   uint32_t getMveAddrModeRQOpValue(const MCInst &MI, unsigned OpIdx,
216                                    SmallVectorImpl<MCFixup> &Fixups,
217                                    const MCSubtargetInfo &STI) const;
218 
219   /// getMveAddrModeQOpValue - Return encoding info for 'reg +/- imm7<<{shift}'
220   /// operand.
221   template<int shift>
222   uint32_t getMveAddrModeQOpValue(const MCInst &MI, unsigned OpIdx,
223                                   SmallVectorImpl<MCFixup> &Fixups,
224                                   const MCSubtargetInfo &STI) const;
225 
226   /// getLdStSORegOpValue - Return encoding info for 'reg +/- reg shop imm'
227   /// operand as needed by load/store instructions.
228   uint32_t getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
229                                SmallVectorImpl<MCFixup> &Fixups,
230                                const MCSubtargetInfo &STI) const;
231 
232   /// getLdStmModeOpValue - Return encoding for load/store multiple mode.
233   uint32_t getLdStmModeOpValue(const MCInst &MI, unsigned OpIdx,
234                                SmallVectorImpl<MCFixup> &Fixups,
235                                const MCSubtargetInfo &STI) const {
236     ARM_AM::AMSubMode Mode = (ARM_AM::AMSubMode)MI.getOperand(OpIdx).getImm();
237     switch (Mode) {
238     default: llvm_unreachable("Unknown addressing sub-mode!");
239     case ARM_AM::da: return 0;
240     case ARM_AM::ia: return 1;
241     case ARM_AM::db: return 2;
242     case ARM_AM::ib: return 3;
243     }
244   }
245 
246   /// getShiftOp - Return the shift opcode (bit[6:5]) of the immediate value.
247   ///
248   unsigned getShiftOp(ARM_AM::ShiftOpc ShOpc) const {
249     switch (ShOpc) {
250     case ARM_AM::no_shift:
251     case ARM_AM::lsl: return 0;
252     case ARM_AM::lsr: return 1;
253     case ARM_AM::asr: return 2;
254     case ARM_AM::ror:
255     case ARM_AM::rrx: return 3;
256     default:
257       llvm_unreachable("Invalid ShiftOpc!");
258     }
259   }
260 
261   /// getAddrMode2OffsetOpValue - Return encoding for am2offset operands.
262   uint32_t getAddrMode2OffsetOpValue(const MCInst &MI, unsigned OpIdx,
263                                      SmallVectorImpl<MCFixup> &Fixups,
264                                      const MCSubtargetInfo &STI) const;
265 
266   /// getPostIdxRegOpValue - Return encoding for postidx_reg operands.
267   uint32_t getPostIdxRegOpValue(const MCInst &MI, unsigned OpIdx,
268                                 SmallVectorImpl<MCFixup> &Fixups,
269                                 const MCSubtargetInfo &STI) const;
270 
271   /// getAddrMode3OffsetOpValue - Return encoding for am3offset operands.
272   uint32_t getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
273                                      SmallVectorImpl<MCFixup> &Fixups,
274                                      const MCSubtargetInfo &STI) const;
275 
276   /// getAddrMode3OpValue - Return encoding for addrmode3 operands.
277   uint32_t getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
278                                SmallVectorImpl<MCFixup> &Fixups,
279                                const MCSubtargetInfo &STI) const;
280 
281   /// getAddrModeThumbSPOpValue - Return encoding info for 'reg +/- imm12'
282   /// operand.
283   uint32_t getAddrModeThumbSPOpValue(const MCInst &MI, unsigned OpIdx,
284                                      SmallVectorImpl<MCFixup> &Fixups,
285                                      const MCSubtargetInfo &STI) const;
286 
287   /// getAddrModeISOpValue - Encode the t_addrmode_is# operands.
288   uint32_t getAddrModeISOpValue(const MCInst &MI, unsigned OpIdx,
289                                 SmallVectorImpl<MCFixup> &Fixups,
290                                 const MCSubtargetInfo &STI) const;
291 
292   /// getAddrModePCOpValue - Return encoding for t_addrmode_pc operands.
293   uint32_t getAddrModePCOpValue(const MCInst &MI, unsigned OpIdx,
294                                 SmallVectorImpl<MCFixup> &Fixups,
295                                 const MCSubtargetInfo &STI) const;
296 
297   /// getAddrMode5OpValue - Return encoding info for 'reg +/- (imm8 << 2)' operand.
298   uint32_t getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
299                                SmallVectorImpl<MCFixup> &Fixups,
300                                const MCSubtargetInfo &STI) const;
301 
302   /// getAddrMode5FP16OpValue - Return encoding info for 'reg +/- (imm8 << 1)' operand.
303   uint32_t getAddrMode5FP16OpValue(const MCInst &MI, unsigned OpIdx,
304                                SmallVectorImpl<MCFixup> &Fixups,
305                                const MCSubtargetInfo &STI) const;
306 
307   /// getCCOutOpValue - Return encoding of the 's' bit.
308   unsigned getCCOutOpValue(const MCInst &MI, unsigned Op,
309                            SmallVectorImpl<MCFixup> &Fixups,
310                            const MCSubtargetInfo &STI) const {
311     // The operand is either reg0 or CPSR. The 's' bit is encoded as '0' or
312     // '1' respectively.
313     return MI.getOperand(Op).getReg() == ARM::CPSR;
314   }
315 
316   unsigned getModImmOpValue(const MCInst &MI, unsigned Op,
317                             SmallVectorImpl<MCFixup> &Fixups,
318                             const MCSubtargetInfo &ST) const {
319     const MCOperand &MO = MI.getOperand(Op);
320 
321     // Support for fixups (MCFixup)
322     if (MO.isExpr()) {
323       const MCExpr *Expr = MO.getExpr();
324       // Fixups resolve to plain values that need to be encoded.
325       MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_mod_imm);
326       Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
327       return 0;
328     }
329 
330     // Immediate is already in its encoded format
331     return MO.getImm();
332   }
333 
334   /// getT2SOImmOpValue - Return an encoded 12-bit shifted-immediate value.
335   unsigned getT2SOImmOpValue(const MCInst &MI, unsigned Op,
336                            SmallVectorImpl<MCFixup> &Fixups,
337                            const MCSubtargetInfo &STI) const {
338     const MCOperand &MO = MI.getOperand(Op);
339 
340     // Support for fixups (MCFixup)
341     if (MO.isExpr()) {
342       const MCExpr *Expr = MO.getExpr();
343       // Fixups resolve to plain values that need to be encoded.
344       MCFixupKind Kind = MCFixupKind(ARM::fixup_t2_so_imm);
345       Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
346       return 0;
347     }
348     unsigned SoImm = MO.getImm();
349     unsigned Encoded =  ARM_AM::getT2SOImmVal(SoImm);
350     assert(Encoded != ~0U && "Not a Thumb2 so_imm value?");
351     return Encoded;
352   }
353 
354   unsigned getT2AddrModeSORegOpValue(const MCInst &MI, unsigned OpNum,
355     SmallVectorImpl<MCFixup> &Fixups,
356     const MCSubtargetInfo &STI) const;
357   template<unsigned Bits, unsigned Shift>
358   unsigned getT2AddrModeImmOpValue(const MCInst &MI, unsigned OpNum,
359     SmallVectorImpl<MCFixup> &Fixups,
360     const MCSubtargetInfo &STI) const;
361   unsigned getT2AddrModeImm8OffsetOpValue(const MCInst &MI, unsigned OpNum,
362     SmallVectorImpl<MCFixup> &Fixups,
363     const MCSubtargetInfo &STI) const;
364 
365   /// getSORegOpValue - Return an encoded so_reg shifted register value.
366   unsigned getSORegRegOpValue(const MCInst &MI, unsigned Op,
367                            SmallVectorImpl<MCFixup> &Fixups,
368                            const MCSubtargetInfo &STI) const;
369   unsigned getSORegImmOpValue(const MCInst &MI, unsigned Op,
370                            SmallVectorImpl<MCFixup> &Fixups,
371                            const MCSubtargetInfo &STI) const;
372   unsigned getT2SORegOpValue(const MCInst &MI, unsigned Op,
373                              SmallVectorImpl<MCFixup> &Fixups,
374                              const MCSubtargetInfo &STI) const;
375 
376   unsigned getNEONVcvtImm32OpValue(const MCInst &MI, unsigned Op,
377                                    SmallVectorImpl<MCFixup> &Fixups,
378                                    const MCSubtargetInfo &STI) const {
379     return 64 - MI.getOperand(Op).getImm();
380   }
381 
382   unsigned getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
383                                       SmallVectorImpl<MCFixup> &Fixups,
384                                       const MCSubtargetInfo &STI) const;
385 
386   unsigned getRegisterListOpValue(const MCInst &MI, unsigned Op,
387                                   SmallVectorImpl<MCFixup> &Fixups,
388                                   const MCSubtargetInfo &STI) const;
389   unsigned getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
390                                       SmallVectorImpl<MCFixup> &Fixups,
391                                       const MCSubtargetInfo &STI) const;
392   unsigned getAddrMode6OneLane32AddressOpValue(const MCInst &MI, unsigned Op,
393                                         SmallVectorImpl<MCFixup> &Fixups,
394                                         const MCSubtargetInfo &STI) const;
395   unsigned getAddrMode6DupAddressOpValue(const MCInst &MI, unsigned Op,
396                                         SmallVectorImpl<MCFixup> &Fixups,
397                                         const MCSubtargetInfo &STI) const;
398   unsigned getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
399                                      SmallVectorImpl<MCFixup> &Fixups,
400                                      const MCSubtargetInfo &STI) const;
401 
402   unsigned getShiftRight8Imm(const MCInst &MI, unsigned Op,
403                              SmallVectorImpl<MCFixup> &Fixups,
404                              const MCSubtargetInfo &STI) const;
405   unsigned getShiftRight16Imm(const MCInst &MI, unsigned Op,
406                               SmallVectorImpl<MCFixup> &Fixups,
407                               const MCSubtargetInfo &STI) const;
408   unsigned getShiftRight32Imm(const MCInst &MI, unsigned Op,
409                               SmallVectorImpl<MCFixup> &Fixups,
410                               const MCSubtargetInfo &STI) const;
411   unsigned getShiftRight64Imm(const MCInst &MI, unsigned Op,
412                               SmallVectorImpl<MCFixup> &Fixups,
413                               const MCSubtargetInfo &STI) const;
414 
415   unsigned getThumbSRImmOpValue(const MCInst &MI, unsigned Op,
416                                  SmallVectorImpl<MCFixup> &Fixups,
417                                  const MCSubtargetInfo &STI) const;
418 
419   unsigned NEONThumb2DataIPostEncoder(const MCInst &MI,
420                                       unsigned EncodedValue,
421                                       const MCSubtargetInfo &STI) const;
422   unsigned NEONThumb2LoadStorePostEncoder(const MCInst &MI,
423                                           unsigned EncodedValue,
424                                           const MCSubtargetInfo &STI) const;
425   unsigned NEONThumb2DupPostEncoder(const MCInst &MI,
426                                     unsigned EncodedValue,
427                                     const MCSubtargetInfo &STI) const;
428   unsigned NEONThumb2V8PostEncoder(const MCInst &MI,
429                                    unsigned EncodedValue,
430                                    const MCSubtargetInfo &STI) const;
431 
432   unsigned VFPThumb2PostEncoder(const MCInst &MI,
433                                 unsigned EncodedValue,
434                                 const MCSubtargetInfo &STI) const;
435 
436   uint32_t getPowerTwoOpValue(const MCInst &MI, unsigned OpIdx,
437                               SmallVectorImpl<MCFixup> &Fixups,
438                               const MCSubtargetInfo &STI) const;
439 
440   void encodeInstruction(const MCInst &MI, SmallVectorImpl<char> &CB,
441                          SmallVectorImpl<MCFixup> &Fixups,
442                          const MCSubtargetInfo &STI) const override;
443 
444   template <bool isNeg, ARM::Fixups fixup>
445   uint32_t getBFTargetOpValue(const MCInst &MI, unsigned OpIdx,
446                               SmallVectorImpl<MCFixup> &Fixups,
447                               const MCSubtargetInfo &STI) const;
448 
449   uint32_t getBFAfterTargetOpValue(const MCInst &MI, unsigned OpIdx,
450                                    SmallVectorImpl<MCFixup> &Fixups,
451                                    const MCSubtargetInfo &STI) const;
452 
453   uint32_t getVPTMaskOpValue(const MCInst &MI, unsigned OpIdx,
454                              SmallVectorImpl<MCFixup> &Fixups,
455                              const MCSubtargetInfo &STI) const;
456   uint32_t getRestrictedCondCodeOpValue(const MCInst &MI, unsigned OpIdx,
457                                         SmallVectorImpl<MCFixup> &Fixups,
458                                         const MCSubtargetInfo &STI) const;
459   template <unsigned size>
460   uint32_t getMVEPairVectorIndexOpValue(const MCInst &MI, unsigned OpIdx,
461                                         SmallVectorImpl<MCFixup> &Fixups,
462                                         const MCSubtargetInfo &STI) const;
463 };
464 
465 } // end anonymous namespace
466 
467 /// NEONThumb2DataIPostEncoder - Post-process encoded NEON data-processing
468 /// instructions, and rewrite them to their Thumb2 form if we are currently in
469 /// Thumb2 mode.
470 unsigned ARMMCCodeEmitter::NEONThumb2DataIPostEncoder(const MCInst &MI,
471                                                  unsigned EncodedValue,
472                                                  const MCSubtargetInfo &STI) const {
473   if (isThumb2(STI)) {
474     // NEON Thumb2 data-processsing encodings are very simple: bit 24 is moved
475     // to bit 12 of the high half-word (i.e. bit 28), and bits 27-24 are
476     // set to 1111.
477     unsigned Bit24 = EncodedValue & 0x01000000;
478     unsigned Bit28 = Bit24 << 4;
479     EncodedValue &= 0xEFFFFFFF;
480     EncodedValue |= Bit28;
481     EncodedValue |= 0x0F000000;
482   }
483 
484   return EncodedValue;
485 }
486 
487 /// NEONThumb2LoadStorePostEncoder - Post-process encoded NEON load/store
488 /// instructions, and rewrite them to their Thumb2 form if we are currently in
489 /// Thumb2 mode.
490 unsigned ARMMCCodeEmitter::NEONThumb2LoadStorePostEncoder(const MCInst &MI,
491                                                  unsigned EncodedValue,
492                                                  const MCSubtargetInfo &STI) const {
493   if (isThumb2(STI)) {
494     EncodedValue &= 0xF0FFFFFF;
495     EncodedValue |= 0x09000000;
496   }
497 
498   return EncodedValue;
499 }
500 
501 /// NEONThumb2DupPostEncoder - Post-process encoded NEON vdup
502 /// instructions, and rewrite them to their Thumb2 form if we are currently in
503 /// Thumb2 mode.
504 unsigned ARMMCCodeEmitter::NEONThumb2DupPostEncoder(const MCInst &MI,
505                                                  unsigned EncodedValue,
506                                                  const MCSubtargetInfo &STI) const {
507   if (isThumb2(STI)) {
508     EncodedValue &= 0x00FFFFFF;
509     EncodedValue |= 0xEE000000;
510   }
511 
512   return EncodedValue;
513 }
514 
515 /// Post-process encoded NEON v8 instructions, and rewrite them to Thumb2 form
516 /// if we are in Thumb2.
517 unsigned ARMMCCodeEmitter::NEONThumb2V8PostEncoder(const MCInst &MI,
518                                                  unsigned EncodedValue,
519                                                  const MCSubtargetInfo &STI) const {
520   if (isThumb2(STI)) {
521     EncodedValue |= 0xC000000; // Set bits 27-26
522   }
523 
524   return EncodedValue;
525 }
526 
527 /// VFPThumb2PostEncoder - Post-process encoded VFP instructions and rewrite
528 /// them to their Thumb2 form if we are currently in Thumb2 mode.
529 unsigned ARMMCCodeEmitter::
530 VFPThumb2PostEncoder(const MCInst &MI, unsigned EncodedValue,
531                      const MCSubtargetInfo &STI) const {
532   if (isThumb2(STI)) {
533     EncodedValue &= 0x0FFFFFFF;
534     EncodedValue |= 0xE0000000;
535   }
536   return EncodedValue;
537 }
538 
539 /// getMachineOpValue - Return binary encoding of operand. If the machine
540 /// operand requires relocation, record the relocation and return zero.
541 unsigned ARMMCCodeEmitter::
542 getMachineOpValue(const MCInst &MI, const MCOperand &MO,
543                   SmallVectorImpl<MCFixup> &Fixups,
544                   const MCSubtargetInfo &STI) const {
545   if (MO.isReg()) {
546     unsigned Reg = MO.getReg();
547     unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg);
548 
549     // In NEON, Q registers are encoded as 2x their register number,
550     // because they're using the same indices as the D registers they
551     // overlap. In MVE, there are no 64-bit vector instructions, so
552     // the encodings all refer to Q-registers by their literal
553     // register number.
554 
555     if (STI.hasFeature(ARM::HasMVEIntegerOps))
556       return RegNo;
557 
558     switch (Reg) {
559     default:
560       return RegNo;
561     case ARM::Q0:  case ARM::Q1:  case ARM::Q2:  case ARM::Q3:
562     case ARM::Q4:  case ARM::Q5:  case ARM::Q6:  case ARM::Q7:
563     case ARM::Q8:  case ARM::Q9:  case ARM::Q10: case ARM::Q11:
564     case ARM::Q12: case ARM::Q13: case ARM::Q14: case ARM::Q15:
565       return 2 * RegNo;
566     }
567   } else if (MO.isImm()) {
568     return static_cast<unsigned>(MO.getImm());
569   } else if (MO.isDFPImm()) {
570     return static_cast<unsigned>(APFloat(bit_cast<double>(MO.getDFPImm()))
571                                      .bitcastToAPInt()
572                                      .getHiBits(32)
573                                      .getLimitedValue());
574   }
575 
576   llvm_unreachable("Unable to encode MCOperand!");
577 }
578 
579 /// getAddrModeImmOpValue - Return encoding info for 'reg +/- imm' operand.
580 bool ARMMCCodeEmitter::
581 EncodeAddrModeOpValues(const MCInst &MI, unsigned OpIdx, unsigned &Reg,
582                        unsigned &Imm, SmallVectorImpl<MCFixup> &Fixups,
583                        const MCSubtargetInfo &STI) const {
584   const MCOperand &MO  = MI.getOperand(OpIdx);
585   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
586 
587   Reg = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
588 
589   int32_t SImm = MO1.getImm();
590   bool isAdd = true;
591 
592   // Special value for #-0
593   if (SImm == INT32_MIN) {
594     SImm = 0;
595     isAdd = false;
596   }
597 
598   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
599   if (SImm < 0) {
600     SImm = -SImm;
601     isAdd = false;
602   }
603 
604   Imm = SImm;
605   return isAdd;
606 }
607 
608 /// getBranchTargetOpValue - Helper function to get the branch target operand,
609 /// which is either an immediate or requires a fixup.
610 static uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
611                                        unsigned FixupKind,
612                                        SmallVectorImpl<MCFixup> &Fixups,
613                                        const MCSubtargetInfo &STI) {
614   const MCOperand &MO = MI.getOperand(OpIdx);
615 
616   // If the destination is an immediate, we have nothing to do.
617   if (MO.isImm()) return MO.getImm();
618   assert(MO.isExpr() && "Unexpected branch target type!");
619   const MCExpr *Expr = MO.getExpr();
620   MCFixupKind Kind = MCFixupKind(FixupKind);
621   Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
622 
623   // All of the information is in the fixup.
624   return 0;
625 }
626 
627 // Thumb BL and BLX use a strange offset encoding where bits 22 and 21 are
628 // determined by negating them and XOR'ing them with bit 23.
629 static int32_t encodeThumbBLOffset(int32_t offset) {
630   offset >>= 1;
631   uint32_t S  = (offset & 0x800000) >> 23;
632   uint32_t J1 = (offset & 0x400000) >> 22;
633   uint32_t J2 = (offset & 0x200000) >> 21;
634   J1 = (~J1 & 0x1);
635   J2 = (~J2 & 0x1);
636   J1 ^= S;
637   J2 ^= S;
638 
639   offset &= ~0x600000;
640   offset |= J1 << 22;
641   offset |= J2 << 21;
642 
643   return offset;
644 }
645 
646 /// getThumbBLTargetOpValue - Return encoding info for immediate branch target.
647 uint32_t ARMMCCodeEmitter::
648 getThumbBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
649                         SmallVectorImpl<MCFixup> &Fixups,
650                         const MCSubtargetInfo &STI) const {
651   const MCOperand MO = MI.getOperand(OpIdx);
652   if (MO.isExpr())
653     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_bl,
654                                     Fixups, STI);
655   return encodeThumbBLOffset(MO.getImm());
656 }
657 
658 /// getThumbBLXTargetOpValue - Return encoding info for Thumb immediate
659 /// BLX branch target.
660 uint32_t ARMMCCodeEmitter::
661 getThumbBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
662                          SmallVectorImpl<MCFixup> &Fixups,
663                          const MCSubtargetInfo &STI) const {
664   const MCOperand MO = MI.getOperand(OpIdx);
665   if (MO.isExpr())
666     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_blx,
667                                     Fixups, STI);
668   return encodeThumbBLOffset(MO.getImm());
669 }
670 
671 /// getThumbBRTargetOpValue - Return encoding info for Thumb branch target.
672 uint32_t ARMMCCodeEmitter::
673 getThumbBRTargetOpValue(const MCInst &MI, unsigned OpIdx,
674                         SmallVectorImpl<MCFixup> &Fixups,
675                         const MCSubtargetInfo &STI) const {
676   const MCOperand MO = MI.getOperand(OpIdx);
677   if (MO.isExpr())
678     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_br,
679                                     Fixups, STI);
680   return (MO.getImm() >> 1);
681 }
682 
683 /// getThumbBCCTargetOpValue - Return encoding info for Thumb branch target.
684 uint32_t ARMMCCodeEmitter::
685 getThumbBCCTargetOpValue(const MCInst &MI, unsigned OpIdx,
686                          SmallVectorImpl<MCFixup> &Fixups,
687                          const MCSubtargetInfo &STI) const {
688   const MCOperand MO = MI.getOperand(OpIdx);
689   if (MO.isExpr())
690     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_bcc,
691                                     Fixups, STI);
692   return (MO.getImm() >> 1);
693 }
694 
695 /// getThumbCBTargetOpValue - Return encoding info for Thumb branch target.
696 uint32_t ARMMCCodeEmitter::
697 getThumbCBTargetOpValue(const MCInst &MI, unsigned OpIdx,
698                         SmallVectorImpl<MCFixup> &Fixups,
699                         const MCSubtargetInfo &STI) const {
700   const MCOperand MO = MI.getOperand(OpIdx);
701   if (MO.isExpr())
702     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_cb, Fixups, STI);
703   return (MO.getImm() >> 1);
704 }
705 
706 /// Return true if this branch has a non-always predication
707 static bool HasConditionalBranch(const MCInst &MI) {
708   int NumOp = MI.getNumOperands();
709   if (NumOp >= 2) {
710     for (int i = 0; i < NumOp-1; ++i) {
711       const MCOperand &MCOp1 = MI.getOperand(i);
712       const MCOperand &MCOp2 = MI.getOperand(i + 1);
713       if (MCOp1.isImm() && MCOp2.isReg() &&
714           (MCOp2.getReg() == 0 || MCOp2.getReg() == ARM::CPSR)) {
715         if (ARMCC::CondCodes(MCOp1.getImm()) != ARMCC::AL)
716           return true;
717       }
718     }
719   }
720   return false;
721 }
722 
723 /// getBranchTargetOpValue - Return encoding info for 24-bit immediate branch
724 /// target.
725 uint32_t ARMMCCodeEmitter::
726 getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
727                        SmallVectorImpl<MCFixup> &Fixups,
728                        const MCSubtargetInfo &STI) const {
729   // FIXME: This really, really shouldn't use TargetMachine. We don't want
730   // coupling between MC and TM anywhere we can help it.
731   if (isThumb2(STI))
732     return
733       ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_condbranch, Fixups, STI);
734   return getARMBranchTargetOpValue(MI, OpIdx, Fixups, STI);
735 }
736 
737 /// getBranchTargetOpValue - Return encoding info for 24-bit immediate branch
738 /// target.
739 uint32_t ARMMCCodeEmitter::
740 getARMBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
741                           SmallVectorImpl<MCFixup> &Fixups,
742                           const MCSubtargetInfo &STI) const {
743   const MCOperand MO = MI.getOperand(OpIdx);
744   if (MO.isExpr()) {
745     if (HasConditionalBranch(MI))
746       return ::getBranchTargetOpValue(MI, OpIdx,
747                                       ARM::fixup_arm_condbranch, Fixups, STI);
748     return ::getBranchTargetOpValue(MI, OpIdx,
749                                     ARM::fixup_arm_uncondbranch, Fixups, STI);
750   }
751 
752   return MO.getImm() >> 2;
753 }
754 
755 uint32_t ARMMCCodeEmitter::
756 getARMBLTargetOpValue(const MCInst &MI, unsigned OpIdx,
757                           SmallVectorImpl<MCFixup> &Fixups,
758                           const MCSubtargetInfo &STI) const {
759   const MCOperand MO = MI.getOperand(OpIdx);
760   if (MO.isExpr()) {
761     if (HasConditionalBranch(MI))
762       return ::getBranchTargetOpValue(MI, OpIdx,
763                                       ARM::fixup_arm_condbl, Fixups, STI);
764     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_uncondbl, Fixups, STI);
765   }
766 
767   return MO.getImm() >> 2;
768 }
769 
770 uint32_t ARMMCCodeEmitter::
771 getARMBLXTargetOpValue(const MCInst &MI, unsigned OpIdx,
772                           SmallVectorImpl<MCFixup> &Fixups,
773                           const MCSubtargetInfo &STI) const {
774   const MCOperand MO = MI.getOperand(OpIdx);
775   if (MO.isExpr())
776     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_blx, Fixups, STI);
777 
778   return MO.getImm() >> 1;
779 }
780 
781 /// getUnconditionalBranchTargetOpValue - Return encoding info for 24-bit
782 /// immediate branch target.
783 uint32_t ARMMCCodeEmitter::getThumbBranchTargetOpValue(
784     const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
785     const MCSubtargetInfo &STI) const {
786   unsigned Val = 0;
787   const MCOperand MO = MI.getOperand(OpIdx);
788 
789   if(MO.isExpr())
790     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_uncondbranch, Fixups, STI);
791   else
792     Val = MO.getImm() >> 1;
793 
794   bool I  = (Val & 0x800000);
795   bool J1 = (Val & 0x400000);
796   bool J2 = (Val & 0x200000);
797   if (I ^ J1)
798     Val &= ~0x400000;
799   else
800     Val |= 0x400000;
801 
802   if (I ^ J2)
803     Val &= ~0x200000;
804   else
805     Val |= 0x200000;
806 
807   return Val;
808 }
809 
810 /// getAdrLabelOpValue - Return encoding info for 12-bit shifted-immediate
811 /// ADR label target.
812 uint32_t ARMMCCodeEmitter::
813 getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
814                    SmallVectorImpl<MCFixup> &Fixups,
815                    const MCSubtargetInfo &STI) const {
816   const MCOperand MO = MI.getOperand(OpIdx);
817   if (MO.isExpr())
818     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_adr_pcrel_12,
819                                     Fixups, STI);
820   int64_t offset = MO.getImm();
821   uint32_t Val = 0x2000;
822 
823   int SoImmVal;
824   if (offset == INT32_MIN) {
825     Val = 0x1000;
826     SoImmVal = 0;
827   } else if (offset < 0) {
828     Val = 0x1000;
829     offset *= -1;
830     SoImmVal = ARM_AM::getSOImmVal(offset);
831     if(SoImmVal == -1) {
832       Val = 0x2000;
833       offset *= -1;
834       SoImmVal = ARM_AM::getSOImmVal(offset);
835     }
836   } else {
837     SoImmVal = ARM_AM::getSOImmVal(offset);
838     if(SoImmVal == -1) {
839       Val = 0x1000;
840       offset *= -1;
841       SoImmVal = ARM_AM::getSOImmVal(offset);
842     }
843   }
844 
845   assert(SoImmVal != -1 && "Not a valid so_imm value!");
846 
847   Val |= SoImmVal;
848   return Val;
849 }
850 
851 /// getT2AdrLabelOpValue - Return encoding info for 12-bit immediate ADR label
852 /// target.
853 uint32_t ARMMCCodeEmitter::
854 getT2AdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
855                    SmallVectorImpl<MCFixup> &Fixups,
856                    const MCSubtargetInfo &STI) const {
857   const MCOperand MO = MI.getOperand(OpIdx);
858   if (MO.isExpr())
859     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_t2_adr_pcrel_12,
860                                     Fixups, STI);
861   int32_t Val = MO.getImm();
862   if (Val == INT32_MIN)
863     Val = 0x1000;
864   else if (Val < 0) {
865     Val *= -1;
866     Val |= 0x1000;
867   }
868   return Val;
869 }
870 
871 /// getITMaskOpValue - Return the architectural encoding of an IT
872 /// predication mask, given the MCOperand format.
873 uint32_t ARMMCCodeEmitter::
874 getITMaskOpValue(const MCInst &MI, unsigned OpIdx,
875                  SmallVectorImpl<MCFixup> &Fixups,
876                  const MCSubtargetInfo &STI) const {
877   const MCOperand MaskMO = MI.getOperand(OpIdx);
878   assert(MaskMO.isImm() && "Unexpected operand type!");
879 
880   unsigned Mask = MaskMO.getImm();
881 
882   // IT masks are encoded as a sequence of replacement low-order bits
883   // for the condition code. So if the low bit of the starting
884   // condition code is 1, then we have to flip all the bits above the
885   // terminating bit (which is the lowest 1 bit).
886   assert(OpIdx > 0 && "IT mask appears first!");
887   const MCOperand CondMO = MI.getOperand(OpIdx-1);
888   assert(CondMO.isImm() && "Unexpected operand type!");
889   if (CondMO.getImm() & 1) {
890     unsigned LowBit = Mask & -Mask;
891     unsigned BitsAboveLowBit = 0xF & (-LowBit << 1);
892     Mask ^= BitsAboveLowBit;
893   }
894 
895   return Mask;
896 }
897 
898 /// getThumbAdrLabelOpValue - Return encoding info for 8-bit immediate ADR label
899 /// target.
900 uint32_t ARMMCCodeEmitter::
901 getThumbAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
902                    SmallVectorImpl<MCFixup> &Fixups,
903                    const MCSubtargetInfo &STI) const {
904   const MCOperand MO = MI.getOperand(OpIdx);
905   if (MO.isExpr())
906     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_thumb_adr_pcrel_10,
907                                     Fixups, STI);
908   return MO.getImm();
909 }
910 
911 /// getThumbAddrModeRegRegOpValue - Return encoding info for 'reg + reg'
912 /// operand.
913 uint32_t ARMMCCodeEmitter::
914 getThumbAddrModeRegRegOpValue(const MCInst &MI, unsigned OpIdx,
915                               SmallVectorImpl<MCFixup> &,
916                               const MCSubtargetInfo &STI) const {
917   // [Rn, Rm]
918   //   {5-3} = Rm
919   //   {2-0} = Rn
920   const MCOperand &MO1 = MI.getOperand(OpIdx);
921   const MCOperand &MO2 = MI.getOperand(OpIdx + 1);
922   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
923   unsigned Rm = CTX.getRegisterInfo()->getEncodingValue(MO2.getReg());
924   return (Rm << 3) | Rn;
925 }
926 
927 /// getMVEShiftImmOpValue - Return encoding info for the 'sz:imm5'
928 /// operand.
929 uint32_t
930 ARMMCCodeEmitter::getMVEShiftImmOpValue(const MCInst &MI, unsigned OpIdx,
931                                         SmallVectorImpl<MCFixup> &Fixups,
932                                         const MCSubtargetInfo &STI) const {
933   // {4-0} = szimm5
934   // The value we are trying to encode is an immediate between either the
935   // range of [1-7] or [1-15] depending on whether we are dealing with the
936   // u8/s8 or the u16/s16 variants respectively.
937   // This value is encoded as follows, if ShiftImm is the value within those
938   // ranges then the encoding szimm5 = ShiftImm + size, where size is either 8
939   // or 16.
940 
941   unsigned Size, ShiftImm;
942   switch(MI.getOpcode()) {
943     case ARM::MVE_VSHLL_imms16bh:
944     case ARM::MVE_VSHLL_imms16th:
945     case ARM::MVE_VSHLL_immu16bh:
946     case ARM::MVE_VSHLL_immu16th:
947       Size = 16;
948       break;
949     case ARM::MVE_VSHLL_imms8bh:
950     case ARM::MVE_VSHLL_imms8th:
951     case ARM::MVE_VSHLL_immu8bh:
952     case ARM::MVE_VSHLL_immu8th:
953       Size = 8;
954       break;
955     default:
956       llvm_unreachable("Use of operand not supported by this instruction");
957   }
958   ShiftImm = MI.getOperand(OpIdx).getImm();
959   return Size + ShiftImm;
960 }
961 
962 /// getAddrModeImm12OpValue - Return encoding info for 'reg +/- imm12' operand.
963 uint32_t ARMMCCodeEmitter::
964 getAddrModeImm12OpValue(const MCInst &MI, unsigned OpIdx,
965                         SmallVectorImpl<MCFixup> &Fixups,
966                         const MCSubtargetInfo &STI) const {
967   // {17-13} = reg
968   // {12}    = (U)nsigned (add == '1', sub == '0')
969   // {11-0}  = imm12
970   unsigned Reg = 0, Imm12 = 0;
971   bool isAdd = true;
972   // If The first operand isn't a register, we have a label reference.
973   const MCOperand &MO = MI.getOperand(OpIdx);
974   if (MO.isReg()) {
975     const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
976     if (MO1.isImm()) {
977       isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm12, Fixups, STI);
978     } else if (MO1.isExpr()) {
979       assert(!isThumb(STI) && !isThumb2(STI) &&
980              "Thumb mode requires different encoding");
981       Reg = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
982       isAdd = false; // 'U' bit is set as part of the fixup.
983       MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_ldst_abs_12);
984       Fixups.push_back(MCFixup::create(0, MO1.getExpr(), Kind, MI.getLoc()));
985     }
986   } else if (MO.isExpr()) {
987     Reg = CTX.getRegisterInfo()->getEncodingValue(ARM::PC); // Rn is PC.
988     isAdd = false; // 'U' bit is set as part of the fixup.
989     MCFixupKind Kind;
990     if (isThumb2(STI))
991       Kind = MCFixupKind(ARM::fixup_t2_ldst_pcrel_12);
992     else
993       Kind = MCFixupKind(ARM::fixup_arm_ldst_pcrel_12);
994     Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
995 
996     ++MCNumCPRelocations;
997   } else {
998     Reg = ARM::PC;
999     int32_t Offset = MO.getImm();
1000     if (Offset == INT32_MIN) {
1001       Offset = 0;
1002       isAdd = false;
1003     } else if (Offset < 0) {
1004       Offset *= -1;
1005       isAdd = false;
1006     }
1007     Imm12 = Offset;
1008   }
1009   uint32_t Binary = Imm12 & 0xfff;
1010   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
1011   if (isAdd)
1012     Binary |= (1 << 12);
1013   Binary |= (Reg << 13);
1014   return Binary;
1015 }
1016 
1017 template<unsigned Bits, unsigned Shift>
1018 uint32_t ARMMCCodeEmitter::
1019 getT2ScaledImmOpValue(const MCInst &MI, unsigned OpIdx,
1020                       SmallVectorImpl<MCFixup> &Fixups,
1021                       const MCSubtargetInfo &STI) const {
1022   // FIXME: The immediate operand should have already been encoded like this
1023   // before ever getting here. The encoder method should just need to combine
1024   // the MI operands for the register and the offset into a single
1025   // representation for the complex operand in the .td file. This isn't just
1026   // style, unfortunately. As-is, we can't represent the distinct encoding
1027   // for #-0.
1028 
1029   // {Bits}    = (U)nsigned (add == '1', sub == '0')
1030   // {(Bits-1)-0}  = immediate
1031   int32_t Imm = MI.getOperand(OpIdx).getImm();
1032   bool isAdd = Imm >= 0;
1033 
1034   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
1035   if (Imm < 0)
1036     Imm = -(uint32_t)Imm;
1037 
1038   Imm >>= Shift;
1039 
1040   uint32_t Binary = Imm & ((1U << Bits) - 1);
1041   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
1042   if (isAdd)
1043     Binary |= (1U << Bits);
1044   return Binary;
1045 }
1046 
1047 /// getMveAddrModeRQOpValue - Return encoding info for 'reg, vreg'
1048 /// operand.
1049 uint32_t ARMMCCodeEmitter::
1050 getMveAddrModeRQOpValue(const MCInst &MI, unsigned OpIdx,
1051                         SmallVectorImpl<MCFixup> &Fixups,
1052                         const MCSubtargetInfo &STI) const {
1053     // {6-3} Rn
1054     // {2-0} Qm
1055     const MCOperand &M0 = MI.getOperand(OpIdx);
1056     const MCOperand &M1 = MI.getOperand(OpIdx + 1);
1057 
1058     unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(M0.getReg());
1059     unsigned Qm = CTX.getRegisterInfo()->getEncodingValue(M1.getReg());
1060 
1061     assert(Qm < 8 && "Qm is supposed to be encodable in 3 bits");
1062 
1063     return (Rn << 3) | Qm;
1064 }
1065 
1066 /// getMveAddrModeRQOpValue - Return encoding info for 'reg, vreg'
1067 /// operand.
1068 template<int shift>
1069 uint32_t ARMMCCodeEmitter::
1070 getMveAddrModeQOpValue(const MCInst &MI, unsigned OpIdx,
1071                         SmallVectorImpl<MCFixup> &Fixups,
1072                         const MCSubtargetInfo &STI) const {
1073     // {10-8} Qm
1074     // {7-0} Imm
1075     const MCOperand &M0 = MI.getOperand(OpIdx);
1076     const MCOperand &M1 = MI.getOperand(OpIdx + 1);
1077 
1078     unsigned Qm = CTX.getRegisterInfo()->getEncodingValue(M0.getReg());
1079     int32_t Imm = M1.getImm();
1080 
1081     bool isAdd = Imm >= 0;
1082 
1083     Imm >>= shift;
1084 
1085     if (!isAdd)
1086       Imm = -(uint32_t)Imm;
1087 
1088     Imm &= 0x7f;
1089 
1090     if (isAdd)
1091       Imm |= 0x80;
1092 
1093     assert(Qm < 8 && "Qm is supposed to be encodable in 3 bits");
1094 
1095     return (Qm << 8) | Imm;
1096 }
1097 
1098 /// getT2AddrModeImm8s4OpValue - Return encoding info for
1099 /// 'reg +/- imm8<<2' operand.
1100 uint32_t ARMMCCodeEmitter::
1101 getT2AddrModeImm8s4OpValue(const MCInst &MI, unsigned OpIdx,
1102                         SmallVectorImpl<MCFixup> &Fixups,
1103                         const MCSubtargetInfo &STI) const {
1104   // {12-9} = reg
1105   // {8}    = (U)nsigned (add == '1', sub == '0')
1106   // {7-0}  = imm8
1107   unsigned Reg, Imm8;
1108   bool isAdd = true;
1109   // If The first operand isn't a register, we have a label reference.
1110   const MCOperand &MO = MI.getOperand(OpIdx);
1111   if (!MO.isReg()) {
1112     Reg = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
1113     Imm8 = 0;
1114     isAdd = false ; // 'U' bit is set as part of the fixup.
1115 
1116     assert(MO.isExpr() && "Unexpected machine operand type!");
1117     const MCExpr *Expr = MO.getExpr();
1118     MCFixupKind Kind = MCFixupKind(ARM::fixup_t2_pcrel_10);
1119     Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
1120 
1121     ++MCNumCPRelocations;
1122   } else
1123     isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups, STI);
1124 
1125   // FIXME: The immediate operand should have already been encoded like this
1126   // before ever getting here. The encoder method should just need to combine
1127   // the MI operands for the register and the offset into a single
1128   // representation for the complex operand in the .td file. This isn't just
1129   // style, unfortunately. As-is, we can't represent the distinct encoding
1130   // for #-0.
1131   assert(((Imm8 & 0x3) == 0) && "Not a valid immediate!");
1132   uint32_t Binary = (Imm8 >> 2) & 0xff;
1133   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
1134   if (isAdd)
1135     Binary |= (1 << 8);
1136   Binary |= (Reg << 9);
1137   return Binary;
1138 }
1139 
1140 /// getT2AddrModeImm7s4OpValue - Return encoding info for
1141 /// 'reg +/- imm7<<2' operand.
1142 uint32_t
1143 ARMMCCodeEmitter::getT2AddrModeImm7s4OpValue(const MCInst &MI, unsigned OpIdx,
1144                                              SmallVectorImpl<MCFixup> &Fixups,
1145                                              const MCSubtargetInfo &STI) const {
1146   // {11-8} = reg
1147   // {7}    = (A)dd (add == '1', sub == '0')
1148   // {6-0}  = imm7
1149   unsigned Reg, Imm7;
1150   // If The first operand isn't a register, we have a label reference.
1151   bool isAdd = EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm7, Fixups, STI);
1152 
1153   // FIXME: The immediate operand should have already been encoded like this
1154   // before ever getting here. The encoder method should just need to combine
1155   // the MI operands for the register and the offset into a single
1156   // representation for the complex operand in the .td file. This isn't just
1157   // style, unfortunately. As-is, we can't represent the distinct encoding
1158   // for #-0.
1159   uint32_t Binary = (Imm7 >> 2) & 0xff;
1160   // Immediate is always encoded as positive. The 'A' bit controls add vs sub.
1161   if (isAdd)
1162     Binary |= (1 << 7);
1163   Binary |= (Reg << 8);
1164   return Binary;
1165 }
1166 
1167 /// getT2AddrModeImm0_1020s4OpValue - Return encoding info for
1168 /// 'reg + imm8<<2' operand.
1169 uint32_t ARMMCCodeEmitter::
1170 getT2AddrModeImm0_1020s4OpValue(const MCInst &MI, unsigned OpIdx,
1171                         SmallVectorImpl<MCFixup> &Fixups,
1172                         const MCSubtargetInfo &STI) const {
1173   // {11-8} = reg
1174   // {7-0}  = imm8
1175   const MCOperand &MO = MI.getOperand(OpIdx);
1176   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1177   unsigned Reg = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1178   unsigned Imm8 = MO1.getImm();
1179   return (Reg << 8) | Imm8;
1180 }
1181 
1182 uint32_t ARMMCCodeEmitter::getHiLoImmOpValue(const MCInst &MI, unsigned OpIdx,
1183                                              SmallVectorImpl<MCFixup> &Fixups,
1184                                              const MCSubtargetInfo &STI) const {
1185   // {20-16} = imm{15-12}
1186   // {11-0}  = imm{11-0}
1187   const MCOperand &MO = MI.getOperand(OpIdx);
1188   if (MO.isImm())
1189     // Hi / lo bits already extracted during earlier passes.
1190     return static_cast<unsigned>(MO.getImm());
1191 
1192   // Handle :upper16:, :lower16:, :upper8_15:, :upper0_7:, :lower8_15:
1193   // :lower0_7: assembly prefixes.
1194   const MCExpr *E = MO.getExpr();
1195   MCFixupKind Kind;
1196   if (E->getKind() == MCExpr::Target) {
1197     const ARMMCExpr *ARM16Expr = cast<ARMMCExpr>(E);
1198     E = ARM16Expr->getSubExpr();
1199 
1200     if (const MCConstantExpr *MCE = dyn_cast<MCConstantExpr>(E)) {
1201       const int64_t Value = MCE->getValue();
1202       if (Value > UINT32_MAX)
1203         report_fatal_error("constant value truncated (limited to 32-bit)");
1204 
1205       switch (ARM16Expr->getKind()) {
1206       case ARMMCExpr::VK_ARM_HI16:
1207         return (int32_t(Value) & 0xffff0000) >> 16;
1208       case ARMMCExpr::VK_ARM_LO16:
1209         return (int32_t(Value) & 0x0000ffff);
1210 
1211       case ARMMCExpr::VK_ARM_HI_8_15:
1212         return (int32_t(Value) & 0xff000000) >> 24;
1213       case ARMMCExpr::VK_ARM_HI_0_7:
1214         return (int32_t(Value) & 0x00ff0000) >> 16;
1215       case ARMMCExpr::VK_ARM_LO_8_15:
1216         return (int32_t(Value) & 0x0000ff00) >> 8;
1217       case ARMMCExpr::VK_ARM_LO_0_7:
1218         return (int32_t(Value) & 0x000000ff);
1219 
1220       default: llvm_unreachable("Unsupported ARMFixup");
1221       }
1222     }
1223 
1224     switch (ARM16Expr->getKind()) {
1225     default: llvm_unreachable("Unsupported ARMFixup");
1226     case ARMMCExpr::VK_ARM_HI16:
1227       Kind = MCFixupKind(isThumb(STI) ? ARM::fixup_t2_movt_hi16
1228                                       : ARM::fixup_arm_movt_hi16);
1229       break;
1230     case ARMMCExpr::VK_ARM_LO16:
1231       Kind = MCFixupKind(isThumb(STI) ? ARM::fixup_t2_movw_lo16
1232                                       : ARM::fixup_arm_movw_lo16);
1233       break;
1234     case ARMMCExpr::VK_ARM_HI_8_15:
1235       if (!isThumb(STI))
1236         llvm_unreachable(":upper_8_15: not supported in Arm state");
1237       Kind = MCFixupKind(ARM::fixup_arm_thumb_upper_8_15);
1238       break;
1239     case ARMMCExpr::VK_ARM_HI_0_7:
1240       if (!isThumb(STI))
1241         llvm_unreachable(":upper_0_7: not supported in Arm state");
1242       Kind = MCFixupKind(ARM::fixup_arm_thumb_upper_0_7);
1243       break;
1244     case ARMMCExpr::VK_ARM_LO_8_15:
1245       if (!isThumb(STI))
1246         llvm_unreachable(":lower_8_15: not supported in Arm state");
1247       Kind = MCFixupKind(ARM::fixup_arm_thumb_lower_8_15);
1248       break;
1249     case ARMMCExpr::VK_ARM_LO_0_7:
1250       if (!isThumb(STI))
1251         llvm_unreachable(":lower_0_7: not supported in Arm state");
1252       Kind = MCFixupKind(ARM::fixup_arm_thumb_lower_0_7);
1253       break;
1254     }
1255 
1256     Fixups.push_back(MCFixup::create(0, E, Kind, MI.getLoc()));
1257     return 0;
1258   }
1259   // If the expression doesn't have :upper16:, :lower16: on it, it's just a
1260   // plain immediate expression, previously those evaluated to the lower 16 bits
1261   // of the expression regardless of whether we have a movt or a movw, but that
1262   // led to misleadingly results.  This is disallowed in the AsmParser in
1263   // validateInstruction() so this should never happen.  The same holds for
1264   // thumb1 :upper8_15:, :upper0_7:, lower8_15: or :lower0_7: with movs or adds.
1265   llvm_unreachable("expression without :upper16:, :lower16:, :upper8_15:,"
1266                    ":upper0_7:, lower8_15: or :lower0_7:");
1267 }
1268 
1269 uint32_t ARMMCCodeEmitter::
1270 getLdStSORegOpValue(const MCInst &MI, unsigned OpIdx,
1271                     SmallVectorImpl<MCFixup> &Fixups,
1272                     const MCSubtargetInfo &STI) const {
1273   const MCOperand &MO = MI.getOperand(OpIdx);
1274   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1275   const MCOperand &MO2 = MI.getOperand(OpIdx+2);
1276   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1277   unsigned Rm = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1278   unsigned ShImm = ARM_AM::getAM2Offset(MO2.getImm());
1279   bool isAdd = ARM_AM::getAM2Op(MO2.getImm()) == ARM_AM::add;
1280   ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(MO2.getImm());
1281   unsigned SBits = getShiftOp(ShOp);
1282 
1283   // While "lsr #32" and "asr #32" exist, they are encoded with a 0 in the shift
1284   // amount. However, it would be an easy mistake to make so check here.
1285   assert((ShImm & ~0x1f) == 0 && "Out of range shift amount");
1286 
1287   // {16-13} = Rn
1288   // {12}    = isAdd
1289   // {11-0}  = shifter
1290   //  {3-0}  = Rm
1291   //  {4}    = 0
1292   //  {6-5}  = type
1293   //  {11-7} = imm
1294   uint32_t Binary = Rm;
1295   Binary |= Rn << 13;
1296   Binary |= SBits << 5;
1297   Binary |= ShImm << 7;
1298   if (isAdd)
1299     Binary |= 1 << 12;
1300   return Binary;
1301 }
1302 
1303 uint32_t ARMMCCodeEmitter::
1304 getAddrMode2OffsetOpValue(const MCInst &MI, unsigned OpIdx,
1305                           SmallVectorImpl<MCFixup> &Fixups,
1306                           const MCSubtargetInfo &STI) const {
1307   // {13}     1 == imm12, 0 == Rm
1308   // {12}     isAdd
1309   // {11-0}   imm12/Rm
1310   const MCOperand &MO = MI.getOperand(OpIdx);
1311   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1312   unsigned Imm = MO1.getImm();
1313   bool isAdd = ARM_AM::getAM2Op(Imm) == ARM_AM::add;
1314   bool isReg = MO.getReg() != 0;
1315   uint32_t Binary = ARM_AM::getAM2Offset(Imm);
1316   // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm12
1317   if (isReg) {
1318     ARM_AM::ShiftOpc ShOp = ARM_AM::getAM2ShiftOpc(Imm);
1319     Binary <<= 7;                    // Shift amount is bits [11:7]
1320     Binary |= getShiftOp(ShOp) << 5; // Shift type is bits [6:5]
1321     Binary |= CTX.getRegisterInfo()->getEncodingValue(MO.getReg()); // Rm is bits [3:0]
1322   }
1323   return Binary | (isAdd << 12) | (isReg << 13);
1324 }
1325 
1326 uint32_t ARMMCCodeEmitter::
1327 getPostIdxRegOpValue(const MCInst &MI, unsigned OpIdx,
1328                      SmallVectorImpl<MCFixup> &Fixups,
1329                      const MCSubtargetInfo &STI) const {
1330   // {4}      isAdd
1331   // {3-0}    Rm
1332   const MCOperand &MO = MI.getOperand(OpIdx);
1333   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1334   bool isAdd = MO1.getImm() != 0;
1335   return CTX.getRegisterInfo()->getEncodingValue(MO.getReg()) | (isAdd << 4);
1336 }
1337 
1338 uint32_t ARMMCCodeEmitter::
1339 getAddrMode3OffsetOpValue(const MCInst &MI, unsigned OpIdx,
1340                           SmallVectorImpl<MCFixup> &Fixups,
1341                           const MCSubtargetInfo &STI) const {
1342   // {9}      1 == imm8, 0 == Rm
1343   // {8}      isAdd
1344   // {7-4}    imm7_4/zero
1345   // {3-0}    imm3_0/Rm
1346   const MCOperand &MO = MI.getOperand(OpIdx);
1347   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1348   unsigned Imm = MO1.getImm();
1349   bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
1350   bool isImm = MO.getReg() == 0;
1351   uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
1352   // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
1353   if (!isImm)
1354     Imm8 = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1355   return Imm8 | (isAdd << 8) | (isImm << 9);
1356 }
1357 
1358 uint32_t ARMMCCodeEmitter::
1359 getAddrMode3OpValue(const MCInst &MI, unsigned OpIdx,
1360                     SmallVectorImpl<MCFixup> &Fixups,
1361                     const MCSubtargetInfo &STI) const {
1362   // {13}     1 == imm8, 0 == Rm
1363   // {12-9}   Rn
1364   // {8}      isAdd
1365   // {7-4}    imm7_4/zero
1366   // {3-0}    imm3_0/Rm
1367   const MCOperand &MO = MI.getOperand(OpIdx);
1368   const MCOperand &MO1 = MI.getOperand(OpIdx+1);
1369   const MCOperand &MO2 = MI.getOperand(OpIdx+2);
1370 
1371   // If The first operand isn't a register, we have a label reference.
1372   if (!MO.isReg()) {
1373     unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
1374 
1375     assert(MO.isExpr() && "Unexpected machine operand type!");
1376     const MCExpr *Expr = MO.getExpr();
1377     MCFixupKind Kind = MCFixupKind(ARM::fixup_arm_pcrel_10_unscaled);
1378     Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
1379 
1380     ++MCNumCPRelocations;
1381     return (Rn << 9) | (1 << 13);
1382   }
1383   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1384   unsigned Imm = MO2.getImm();
1385   bool isAdd = ARM_AM::getAM3Op(Imm) == ARM_AM::add;
1386   bool isImm = MO1.getReg() == 0;
1387   uint32_t Imm8 = ARM_AM::getAM3Offset(Imm);
1388   // if reg +/- reg, Rm will be non-zero. Otherwise, we have reg +/- imm8
1389   if (!isImm)
1390     Imm8 = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1391   return (Rn << 9) | Imm8 | (isAdd << 8) | (isImm << 13);
1392 }
1393 
1394 /// getAddrModeThumbSPOpValue - Encode the t_addrmode_sp operands.
1395 uint32_t ARMMCCodeEmitter::
1396 getAddrModeThumbSPOpValue(const MCInst &MI, unsigned OpIdx,
1397                           SmallVectorImpl<MCFixup> &Fixups,
1398                           const MCSubtargetInfo &STI) const {
1399   // [SP, #imm]
1400   //   {7-0} = imm8
1401   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1402   assert(MI.getOperand(OpIdx).getReg() == ARM::SP &&
1403          "Unexpected base register!");
1404 
1405   // The immediate is already shifted for the implicit zeroes, so no change
1406   // here.
1407   return MO1.getImm() & 0xff;
1408 }
1409 
1410 /// getAddrModeISOpValue - Encode the t_addrmode_is# operands.
1411 uint32_t ARMMCCodeEmitter::
1412 getAddrModeISOpValue(const MCInst &MI, unsigned OpIdx,
1413                      SmallVectorImpl<MCFixup> &Fixups,
1414                      const MCSubtargetInfo &STI) const {
1415   // [Rn, #imm]
1416   //   {7-3} = imm5
1417   //   {2-0} = Rn
1418   const MCOperand &MO = MI.getOperand(OpIdx);
1419   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1420   unsigned Rn = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1421   unsigned Imm5 = MO1.getImm();
1422   return ((Imm5 & 0x1f) << 3) | Rn;
1423 }
1424 
1425 /// getAddrModePCOpValue - Return encoding for t_addrmode_pc operands.
1426 uint32_t ARMMCCodeEmitter::
1427 getAddrModePCOpValue(const MCInst &MI, unsigned OpIdx,
1428                      SmallVectorImpl<MCFixup> &Fixups,
1429                      const MCSubtargetInfo &STI) const {
1430   const MCOperand MO = MI.getOperand(OpIdx);
1431   if (MO.isExpr())
1432     return ::getBranchTargetOpValue(MI, OpIdx, ARM::fixup_arm_thumb_cp, Fixups, STI);
1433   return (MO.getImm() >> 2);
1434 }
1435 
1436 /// getAddrMode5OpValue - Return encoding info for 'reg +/- (imm8 << 2)' operand.
1437 uint32_t ARMMCCodeEmitter::
1438 getAddrMode5OpValue(const MCInst &MI, unsigned OpIdx,
1439                     SmallVectorImpl<MCFixup> &Fixups,
1440                     const MCSubtargetInfo &STI) const {
1441   // {12-9} = reg
1442   // {8}    = (U)nsigned (add == '1', sub == '0')
1443   // {7-0}  = imm8
1444   unsigned Reg, Imm8;
1445   bool isAdd;
1446   // If The first operand isn't a register, we have a label reference.
1447   const MCOperand &MO = MI.getOperand(OpIdx);
1448   if (!MO.isReg()) {
1449     Reg = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
1450     Imm8 = 0;
1451     isAdd = false; // 'U' bit is handled as part of the fixup.
1452 
1453     assert(MO.isExpr() && "Unexpected machine operand type!");
1454     const MCExpr *Expr = MO.getExpr();
1455     MCFixupKind Kind;
1456     if (isThumb2(STI))
1457       Kind = MCFixupKind(ARM::fixup_t2_pcrel_10);
1458     else
1459       Kind = MCFixupKind(ARM::fixup_arm_pcrel_10);
1460     Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
1461 
1462     ++MCNumCPRelocations;
1463   } else {
1464     EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups, STI);
1465     isAdd = ARM_AM::getAM5Op(Imm8) == ARM_AM::add;
1466   }
1467 
1468   uint32_t Binary = ARM_AM::getAM5Offset(Imm8);
1469   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
1470   if (isAdd)
1471     Binary |= (1 << 8);
1472   Binary |= (Reg << 9);
1473   return Binary;
1474 }
1475 
1476 /// getAddrMode5FP16OpValue - Return encoding info for 'reg +/- (imm8 << 1)' operand.
1477 uint32_t ARMMCCodeEmitter::
1478 getAddrMode5FP16OpValue(const MCInst &MI, unsigned OpIdx,
1479                     SmallVectorImpl<MCFixup> &Fixups,
1480                     const MCSubtargetInfo &STI) const {
1481   // {12-9} = reg
1482   // {8}    = (U)nsigned (add == '1', sub == '0')
1483   // {7-0}  = imm8
1484   unsigned Reg, Imm8;
1485   bool isAdd;
1486   // If The first operand isn't a register, we have a label reference.
1487   const MCOperand &MO = MI.getOperand(OpIdx);
1488   if (!MO.isReg()) {
1489     Reg = CTX.getRegisterInfo()->getEncodingValue(ARM::PC);   // Rn is PC.
1490     Imm8 = 0;
1491     isAdd = false; // 'U' bit is handled as part of the fixup.
1492 
1493     assert(MO.isExpr() && "Unexpected machine operand type!");
1494     const MCExpr *Expr = MO.getExpr();
1495     MCFixupKind Kind;
1496     if (isThumb2(STI))
1497       Kind = MCFixupKind(ARM::fixup_t2_pcrel_9);
1498     else
1499       Kind = MCFixupKind(ARM::fixup_arm_pcrel_9);
1500     Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
1501 
1502     ++MCNumCPRelocations;
1503   } else {
1504     EncodeAddrModeOpValues(MI, OpIdx, Reg, Imm8, Fixups, STI);
1505     isAdd = ARM_AM::getAM5Op(Imm8) == ARM_AM::add;
1506   }
1507 
1508   uint32_t Binary = ARM_AM::getAM5Offset(Imm8);
1509   // Immediate is always encoded as positive. The 'U' bit controls add vs sub.
1510   if (isAdd)
1511     Binary |= (1 << 8);
1512   Binary |= (Reg << 9);
1513   return Binary;
1514 }
1515 
1516 unsigned ARMMCCodeEmitter::
1517 getSORegRegOpValue(const MCInst &MI, unsigned OpIdx,
1518                 SmallVectorImpl<MCFixup> &Fixups,
1519                 const MCSubtargetInfo &STI) const {
1520   // Sub-operands are [reg, reg, imm]. The first register is Rm, the reg to be
1521   // shifted. The second is Rs, the amount to shift by, and the third specifies
1522   // the type of the shift.
1523   //
1524   // {3-0} = Rm.
1525   // {4}   = 1
1526   // {6-5} = type
1527   // {11-8} = Rs
1528   // {7}    = 0
1529 
1530   const MCOperand &MO  = MI.getOperand(OpIdx);
1531   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1532   const MCOperand &MO2 = MI.getOperand(OpIdx + 2);
1533   ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO2.getImm());
1534 
1535   // Encode Rm.
1536   unsigned Binary = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1537 
1538   // Encode the shift opcode.
1539   unsigned SBits = 0;
1540   unsigned Rs = MO1.getReg();
1541   if (Rs) {
1542     // Set shift operand (bit[7:4]).
1543     // LSL - 0001
1544     // LSR - 0011
1545     // ASR - 0101
1546     // ROR - 0111
1547     switch (SOpc) {
1548     default: llvm_unreachable("Unknown shift opc!");
1549     case ARM_AM::lsl: SBits = 0x1; break;
1550     case ARM_AM::lsr: SBits = 0x3; break;
1551     case ARM_AM::asr: SBits = 0x5; break;
1552     case ARM_AM::ror: SBits = 0x7; break;
1553     }
1554   }
1555 
1556   Binary |= SBits << 4;
1557 
1558   // Encode the shift operation Rs.
1559   // Encode Rs bit[11:8].
1560   assert(ARM_AM::getSORegOffset(MO2.getImm()) == 0);
1561   return Binary | (CTX.getRegisterInfo()->getEncodingValue(Rs) << ARMII::RegRsShift);
1562 }
1563 
1564 unsigned ARMMCCodeEmitter::
1565 getSORegImmOpValue(const MCInst &MI, unsigned OpIdx,
1566                 SmallVectorImpl<MCFixup> &Fixups,
1567                 const MCSubtargetInfo &STI) const {
1568   // Sub-operands are [reg, imm]. The first register is Rm, the reg to be
1569   // shifted. The second is the amount to shift by.
1570   //
1571   // {3-0} = Rm.
1572   // {4}   = 0
1573   // {6-5} = type
1574   // {11-7} = imm
1575 
1576   const MCOperand &MO  = MI.getOperand(OpIdx);
1577   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1578   ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO1.getImm());
1579 
1580   // Encode Rm.
1581   unsigned Binary = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1582 
1583   // Encode the shift opcode.
1584   unsigned SBits = 0;
1585 
1586   // Set shift operand (bit[6:4]).
1587   // LSL - 000
1588   // LSR - 010
1589   // ASR - 100
1590   // ROR - 110
1591   // RRX - 110 and bit[11:8] clear.
1592   switch (SOpc) {
1593   default: llvm_unreachable("Unknown shift opc!");
1594   case ARM_AM::lsl: SBits = 0x0; break;
1595   case ARM_AM::lsr: SBits = 0x2; break;
1596   case ARM_AM::asr: SBits = 0x4; break;
1597   case ARM_AM::ror: SBits = 0x6; break;
1598   case ARM_AM::rrx:
1599     Binary |= 0x60;
1600     return Binary;
1601   }
1602 
1603   // Encode shift_imm bit[11:7].
1604   Binary |= SBits << 4;
1605   unsigned Offset = ARM_AM::getSORegOffset(MO1.getImm());
1606   assert(Offset < 32 && "Offset must be in range 0-31!");
1607   return Binary | (Offset << 7);
1608 }
1609 
1610 
1611 unsigned ARMMCCodeEmitter::
1612 getT2AddrModeSORegOpValue(const MCInst &MI, unsigned OpNum,
1613                 SmallVectorImpl<MCFixup> &Fixups,
1614                 const MCSubtargetInfo &STI) const {
1615   const MCOperand &MO1 = MI.getOperand(OpNum);
1616   const MCOperand &MO2 = MI.getOperand(OpNum+1);
1617   const MCOperand &MO3 = MI.getOperand(OpNum+2);
1618 
1619   // Encoded as [Rn, Rm, imm].
1620   // FIXME: Needs fixup support.
1621   unsigned Value = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1622   Value <<= 4;
1623   Value |= CTX.getRegisterInfo()->getEncodingValue(MO2.getReg());
1624   Value <<= 2;
1625   Value |= MO3.getImm();
1626 
1627   return Value;
1628 }
1629 
1630 template<unsigned Bits, unsigned Shift>
1631 unsigned ARMMCCodeEmitter::
1632 getT2AddrModeImmOpValue(const MCInst &MI, unsigned OpNum,
1633                         SmallVectorImpl<MCFixup> &Fixups,
1634                         const MCSubtargetInfo &STI) const {
1635   const MCOperand &MO1 = MI.getOperand(OpNum);
1636   const MCOperand &MO2 = MI.getOperand(OpNum+1);
1637 
1638   // FIXME: Needs fixup support.
1639   unsigned Value = CTX.getRegisterInfo()->getEncodingValue(MO1.getReg());
1640 
1641   // If the immediate is B bits long, we need B+1 bits in order
1642   // to represent the (inverse of the) sign bit.
1643   Value <<= (Bits + 1);
1644   int32_t tmp = (int32_t)MO2.getImm();
1645   if (tmp == INT32_MIN) { // represents subtracting zero rather than adding it
1646     tmp = 0;
1647   } else if (tmp < 0) {
1648     tmp = abs(tmp);
1649   } else {
1650     Value |= (1U << Bits); // Set the ADD bit
1651   }
1652   Value |= (tmp >> Shift) & ((1U << Bits) - 1);
1653   return Value;
1654 }
1655 
1656 unsigned ARMMCCodeEmitter::
1657 getT2AddrModeImm8OffsetOpValue(const MCInst &MI, unsigned OpNum,
1658                          SmallVectorImpl<MCFixup> &Fixups,
1659                          const MCSubtargetInfo &STI) const {
1660   const MCOperand &MO1 = MI.getOperand(OpNum);
1661 
1662   // FIXME: Needs fixup support.
1663   unsigned Value = 0;
1664   auto tmp = static_cast<uint32_t>(MO1.getImm());
1665   if (static_cast<int32_t>(tmp) < 0)
1666     tmp = -tmp;
1667   else
1668     Value |= 256; // Set the ADD bit
1669   Value |= tmp & 255;
1670   return Value;
1671 }
1672 
1673 unsigned ARMMCCodeEmitter::
1674 getT2SORegOpValue(const MCInst &MI, unsigned OpIdx,
1675                 SmallVectorImpl<MCFixup> &Fixups,
1676                 const MCSubtargetInfo &STI) const {
1677   // Sub-operands are [reg, imm]. The first register is Rm, the reg to be
1678   // shifted. The second is the amount to shift by.
1679   //
1680   // {3-0} = Rm.
1681   // {4}   = 0
1682   // {6-5} = type
1683   // {11-7} = imm
1684 
1685   const MCOperand &MO  = MI.getOperand(OpIdx);
1686   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
1687   ARM_AM::ShiftOpc SOpc = ARM_AM::getSORegShOp(MO1.getImm());
1688 
1689   // Encode Rm.
1690   unsigned Binary = CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1691 
1692   // Encode the shift opcode.
1693   unsigned SBits = 0;
1694   // Set shift operand (bit[6:4]).
1695   // LSL - 000
1696   // LSR - 010
1697   // ASR - 100
1698   // ROR - 110
1699   switch (SOpc) {
1700   default: llvm_unreachable("Unknown shift opc!");
1701   case ARM_AM::lsl: SBits = 0x0; break;
1702   case ARM_AM::lsr: SBits = 0x2; break;
1703   case ARM_AM::asr: SBits = 0x4; break;
1704   case ARM_AM::rrx: [[fallthrough]];
1705   case ARM_AM::ror: SBits = 0x6; break;
1706   }
1707 
1708   Binary |= SBits << 4;
1709   if (SOpc == ARM_AM::rrx)
1710     return Binary;
1711 
1712   // Encode shift_imm bit[11:7].
1713   return Binary | ARM_AM::getSORegOffset(MO1.getImm()) << 7;
1714 }
1715 
1716 unsigned ARMMCCodeEmitter::
1717 getBitfieldInvertedMaskOpValue(const MCInst &MI, unsigned Op,
1718                                SmallVectorImpl<MCFixup> &Fixups,
1719                                const MCSubtargetInfo &STI) const {
1720   // 10 bits. lower 5 bits are the lsb of the mask, high five bits are the
1721   // msb of the mask.
1722   const MCOperand &MO = MI.getOperand(Op);
1723   uint32_t v = ~MO.getImm();
1724   uint32_t lsb = llvm::countr_zero(v);
1725   uint32_t msb = llvm::Log2_32(v);
1726   assert(v != 0 && lsb < 32 && msb < 32 && "Illegal bitfield mask!");
1727   return lsb | (msb << 5);
1728 }
1729 
1730 unsigned ARMMCCodeEmitter::
1731 getRegisterListOpValue(const MCInst &MI, unsigned Op,
1732                        SmallVectorImpl<MCFixup> &Fixups,
1733                        const MCSubtargetInfo &STI) const {
1734   // VLDM/VSTM/VSCCLRM:
1735   //   {12-8} = Vd
1736   //   {7-0}  = Number of registers
1737   //
1738   // LDM/STM:
1739   //   {15-0}  = Bitfield of GPRs.
1740   unsigned Reg = MI.getOperand(Op).getReg();
1741   bool SPRRegs = ARMMCRegisterClasses[ARM::SPRRegClassID].contains(Reg);
1742   bool DPRRegs = ARMMCRegisterClasses[ARM::DPRRegClassID].contains(Reg);
1743 
1744   unsigned Binary = 0;
1745 
1746   if (SPRRegs || DPRRegs) {
1747     // VLDM/VSTM/VSCCLRM
1748     unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg);
1749     unsigned NumRegs = (MI.getNumOperands() - Op) & 0xff;
1750     Binary |= (RegNo & 0x1f) << 8;
1751 
1752     // Ignore VPR
1753     if (MI.getOpcode() == ARM::VSCCLRMD || MI.getOpcode() == ARM::VSCCLRMS)
1754       --NumRegs;
1755     if (SPRRegs)
1756       Binary |= NumRegs;
1757     else
1758       Binary |= NumRegs * 2;
1759   } else {
1760     const MCRegisterInfo &MRI = *CTX.getRegisterInfo();
1761     assert(is_sorted(drop_begin(MI, Op),
1762                      [&](const MCOperand &LHS, const MCOperand &RHS) {
1763                        return MRI.getEncodingValue(LHS.getReg()) <
1764                               MRI.getEncodingValue(RHS.getReg());
1765                      }));
1766     for (unsigned I = Op, E = MI.getNumOperands(); I < E; ++I) {
1767       unsigned RegNo = MRI.getEncodingValue(MI.getOperand(I).getReg());
1768       Binary |= 1 << RegNo;
1769     }
1770   }
1771 
1772   return Binary;
1773 }
1774 
1775 /// getAddrMode6AddressOpValue - Encode an addrmode6 register number along
1776 /// with the alignment operand.
1777 unsigned ARMMCCodeEmitter::
1778 getAddrMode6AddressOpValue(const MCInst &MI, unsigned Op,
1779                            SmallVectorImpl<MCFixup> &Fixups,
1780                            const MCSubtargetInfo &STI) const {
1781   const MCOperand &Reg = MI.getOperand(Op);
1782   const MCOperand &Imm = MI.getOperand(Op + 1);
1783 
1784   unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg.getReg());
1785   unsigned Align = 0;
1786 
1787   switch (Imm.getImm()) {
1788   default: break;
1789   case 2:
1790   case 4:
1791   case 8:  Align = 0x01; break;
1792   case 16: Align = 0x02; break;
1793   case 32: Align = 0x03; break;
1794   }
1795 
1796   return RegNo | (Align << 4);
1797 }
1798 
1799 /// getAddrMode6OneLane32AddressOpValue - Encode an addrmode6 register number
1800 /// along  with the alignment operand for use in VST1 and VLD1 with size 32.
1801 unsigned ARMMCCodeEmitter::
1802 getAddrMode6OneLane32AddressOpValue(const MCInst &MI, unsigned Op,
1803                                     SmallVectorImpl<MCFixup> &Fixups,
1804                                     const MCSubtargetInfo &STI) const {
1805   const MCOperand &Reg = MI.getOperand(Op);
1806   const MCOperand &Imm = MI.getOperand(Op + 1);
1807 
1808   unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg.getReg());
1809   unsigned Align = 0;
1810 
1811   switch (Imm.getImm()) {
1812   default: break;
1813   case 8:
1814   case 16:
1815   case 32: // Default '0' value for invalid alignments of 8, 16, 32 bytes.
1816   case 2: Align = 0x00; break;
1817   case 4: Align = 0x03; break;
1818   }
1819 
1820   return RegNo | (Align << 4);
1821 }
1822 
1823 
1824 /// getAddrMode6DupAddressOpValue - Encode an addrmode6 register number and
1825 /// alignment operand for use in VLD-dup instructions.  This is the same as
1826 /// getAddrMode6AddressOpValue except for the alignment encoding, which is
1827 /// different for VLD4-dup.
1828 unsigned ARMMCCodeEmitter::
1829 getAddrMode6DupAddressOpValue(const MCInst &MI, unsigned Op,
1830                               SmallVectorImpl<MCFixup> &Fixups,
1831                               const MCSubtargetInfo &STI) const {
1832   const MCOperand &Reg = MI.getOperand(Op);
1833   const MCOperand &Imm = MI.getOperand(Op + 1);
1834 
1835   unsigned RegNo = CTX.getRegisterInfo()->getEncodingValue(Reg.getReg());
1836   unsigned Align = 0;
1837 
1838   switch (Imm.getImm()) {
1839   default: break;
1840   case 2:
1841   case 4:
1842   case 8:  Align = 0x01; break;
1843   case 16: Align = 0x03; break;
1844   }
1845 
1846   return RegNo | (Align << 4);
1847 }
1848 
1849 unsigned ARMMCCodeEmitter::
1850 getAddrMode6OffsetOpValue(const MCInst &MI, unsigned Op,
1851                           SmallVectorImpl<MCFixup> &Fixups,
1852                           const MCSubtargetInfo &STI) const {
1853   const MCOperand &MO = MI.getOperand(Op);
1854   if (MO.getReg() == 0) return 0x0D;
1855   return CTX.getRegisterInfo()->getEncodingValue(MO.getReg());
1856 }
1857 
1858 unsigned ARMMCCodeEmitter::
1859 getShiftRight8Imm(const MCInst &MI, unsigned Op,
1860                   SmallVectorImpl<MCFixup> &Fixups,
1861                   const MCSubtargetInfo &STI) const {
1862   return 8 - MI.getOperand(Op).getImm();
1863 }
1864 
1865 unsigned ARMMCCodeEmitter::
1866 getShiftRight16Imm(const MCInst &MI, unsigned Op,
1867                    SmallVectorImpl<MCFixup> &Fixups,
1868                    const MCSubtargetInfo &STI) const {
1869   return 16 - MI.getOperand(Op).getImm();
1870 }
1871 
1872 unsigned ARMMCCodeEmitter::
1873 getShiftRight32Imm(const MCInst &MI, unsigned Op,
1874                    SmallVectorImpl<MCFixup> &Fixups,
1875                    const MCSubtargetInfo &STI) const {
1876   return 32 - MI.getOperand(Op).getImm();
1877 }
1878 
1879 unsigned ARMMCCodeEmitter::
1880 getShiftRight64Imm(const MCInst &MI, unsigned Op,
1881                    SmallVectorImpl<MCFixup> &Fixups,
1882                    const MCSubtargetInfo &STI) const {
1883   return 64 - MI.getOperand(Op).getImm();
1884 }
1885 
1886 void ARMMCCodeEmitter::encodeInstruction(const MCInst &MI,
1887                                          SmallVectorImpl<char> &CB,
1888                                          SmallVectorImpl<MCFixup> &Fixups,
1889                                          const MCSubtargetInfo &STI) const {
1890   // Pseudo instructions don't get encoded.
1891   const MCInstrDesc &Desc = MCII.get(MI.getOpcode());
1892   uint64_t TSFlags = Desc.TSFlags;
1893   if ((TSFlags & ARMII::FormMask) == ARMII::Pseudo)
1894     return;
1895 
1896   int Size;
1897   if (Desc.getSize() == 2 || Desc.getSize() == 4)
1898     Size = Desc.getSize();
1899   else
1900     llvm_unreachable("Unexpected instruction size!");
1901 
1902   auto Endian =
1903       IsLittleEndian ? llvm::endianness::little : llvm::endianness::big;
1904   uint32_t Binary = getBinaryCodeForInstr(MI, Fixups, STI);
1905   if (Size == 2) {
1906     support::endian::write<uint16_t>(CB, Binary, Endian);
1907   } else if (isThumb(STI)) {
1908     // Thumb 32-bit wide instructions need to emit the high order halfword
1909     // first.
1910     support::endian::write<uint16_t>(CB, Binary >> 16, Endian);
1911     support::endian::write<uint16_t>(CB, Binary & 0xffff, Endian);
1912   } else {
1913     support::endian::write<uint32_t>(CB, Binary, Endian);
1914   }
1915   ++MCNumEmitted;  // Keep track of the # of mi's emitted.
1916 }
1917 
1918 template <bool isNeg, ARM::Fixups fixup>
1919 uint32_t
1920 ARMMCCodeEmitter::getBFTargetOpValue(const MCInst &MI, unsigned OpIdx,
1921                                      SmallVectorImpl<MCFixup> &Fixups,
1922                                      const MCSubtargetInfo &STI) const {
1923   const MCOperand MO = MI.getOperand(OpIdx);
1924   if (MO.isExpr())
1925     return ::getBranchTargetOpValue(MI, OpIdx, fixup, Fixups, STI);
1926   return isNeg ? -(MO.getImm() >> 1) : (MO.getImm() >> 1);
1927 }
1928 
1929 uint32_t
1930 ARMMCCodeEmitter::getBFAfterTargetOpValue(const MCInst &MI, unsigned OpIdx,
1931                                           SmallVectorImpl<MCFixup> &Fixups,
1932                                           const MCSubtargetInfo &STI) const {
1933   const MCOperand MO = MI.getOperand(OpIdx);
1934   const MCOperand BranchMO = MI.getOperand(0);
1935 
1936   if (MO.isExpr()) {
1937     assert(BranchMO.isExpr());
1938     const MCExpr *DiffExpr = MCBinaryExpr::createSub(
1939         MO.getExpr(), BranchMO.getExpr(), CTX);
1940     MCFixupKind Kind = MCFixupKind(ARM::fixup_bfcsel_else_target);
1941     Fixups.push_back(llvm::MCFixup::create(0, DiffExpr, Kind, MI.getLoc()));
1942     return 0;
1943   }
1944 
1945   assert(MO.isImm() && BranchMO.isImm());
1946   int Diff = MO.getImm() - BranchMO.getImm();
1947   assert(Diff == 4 || Diff == 2);
1948 
1949   return Diff == 4;
1950 }
1951 
1952 uint32_t ARMMCCodeEmitter::getVPTMaskOpValue(const MCInst &MI, unsigned OpIdx,
1953                                              SmallVectorImpl<MCFixup> &Fixups,
1954                                              const MCSubtargetInfo &STI)const {
1955   const MCOperand MO = MI.getOperand(OpIdx);
1956   assert(MO.isImm() && "Unexpected operand type!");
1957 
1958   int Value = MO.getImm();
1959   int Imm = 0;
1960 
1961   // VPT Masks are actually encoded as a series of invert/don't invert bits,
1962   // rather than true/false bits.
1963   unsigned PrevBit = 0;
1964   for (int i = 3; i >= 0; --i) {
1965     unsigned Bit = (Value >> i) & 1;
1966 
1967     // Check if we are at the end of the mask.
1968     if ((Value & ~(~0U << i)) == 0) {
1969       Imm |= (1 << i);
1970       break;
1971     }
1972 
1973     // Convert the bit in the mask based on the previous bit.
1974     if (Bit != PrevBit)
1975       Imm |= (1 << i);
1976 
1977     PrevBit = Bit;
1978   }
1979 
1980   return Imm;
1981 }
1982 
1983 uint32_t ARMMCCodeEmitter::getRestrictedCondCodeOpValue(
1984     const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
1985     const MCSubtargetInfo &STI) const {
1986 
1987   const MCOperand MO = MI.getOperand(OpIdx);
1988   assert(MO.isImm() && "Unexpected operand type!");
1989 
1990   switch (MO.getImm()) {
1991   default:
1992     assert(0 && "Unexpected Condition!");
1993     return 0;
1994   case ARMCC::HS:
1995   case ARMCC::EQ:
1996     return 0;
1997   case ARMCC::HI:
1998   case ARMCC::NE:
1999     return 1;
2000   case ARMCC::GE:
2001     return 4;
2002   case ARMCC::LT:
2003     return 5;
2004   case ARMCC::GT:
2005     return 6;
2006   case ARMCC::LE:
2007     return 7;
2008   }
2009 }
2010 
2011 uint32_t ARMMCCodeEmitter::
2012 getPowerTwoOpValue(const MCInst &MI, unsigned OpIdx,
2013                    SmallVectorImpl<MCFixup> &Fixups,
2014                    const MCSubtargetInfo &STI) const {
2015   const MCOperand &MO = MI.getOperand(OpIdx);
2016   assert(MO.isImm() && "Unexpected operand type!");
2017   return llvm::countr_zero((uint64_t)MO.getImm());
2018 }
2019 
2020 template <unsigned start>
2021 uint32_t ARMMCCodeEmitter::
2022 getMVEPairVectorIndexOpValue(const MCInst &MI, unsigned OpIdx,
2023                              SmallVectorImpl<MCFixup> &Fixups,
2024                              const MCSubtargetInfo &STI) const {
2025   const MCOperand MO = MI.getOperand(OpIdx);
2026   assert(MO.isImm() && "Unexpected operand type!");
2027 
2028   int Value = MO.getImm();
2029   return Value - start;
2030 }
2031 
2032 #include "ARMGenMCCodeEmitter.inc"
2033 
2034 MCCodeEmitter *llvm::createARMLEMCCodeEmitter(const MCInstrInfo &MCII,
2035                                               MCContext &Ctx) {
2036   return new ARMMCCodeEmitter(MCII, Ctx, true);
2037 }
2038 
2039 MCCodeEmitter *llvm::createARMBEMCCodeEmitter(const MCInstrInfo &MCII,
2040                                               MCContext &Ctx) {
2041   return new ARMMCCodeEmitter(MCII, Ctx, false);
2042 }
2043