xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AArch64/MCTargetDesc/AArch64MCCodeEmitter.cpp (revision cb14a3fe5122c879eae1fb480ed7ce82a699ddb6)
1 //=- AArch64/AArch64MCCodeEmitter.cpp - Convert AArch64 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 AArch64MCCodeEmitter class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "MCTargetDesc/AArch64AddressingModes.h"
14 #include "MCTargetDesc/AArch64FixupKinds.h"
15 #include "MCTargetDesc/AArch64MCExpr.h"
16 #include "Utils/AArch64BaseInfo.h"
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/ADT/Statistic.h"
19 #include "llvm/BinaryFormat/ELF.h"
20 #include "llvm/MC/MCCodeEmitter.h"
21 #include "llvm/MC/MCContext.h"
22 #include "llvm/MC/MCFixup.h"
23 #include "llvm/MC/MCInst.h"
24 #include "llvm/MC/MCInstrInfo.h"
25 #include "llvm/MC/MCRegisterInfo.h"
26 #include "llvm/MC/MCSubtargetInfo.h"
27 #include "llvm/Support/Casting.h"
28 #include "llvm/Support/Endian.h"
29 #include "llvm/Support/EndianStream.h"
30 #include "llvm/Support/ErrorHandling.h"
31 #include "llvm/Support/raw_ostream.h"
32 #include <cassert>
33 #include <cstdint>
34 
35 using namespace llvm;
36 
37 #define DEBUG_TYPE "mccodeemitter"
38 
39 STATISTIC(MCNumEmitted, "Number of MC instructions emitted.");
40 STATISTIC(MCNumFixups, "Number of MC fixups created.");
41 
42 namespace {
43 
44 class AArch64MCCodeEmitter : public MCCodeEmitter {
45   MCContext &Ctx;
46 
47 public:
48   AArch64MCCodeEmitter(const MCInstrInfo &, MCContext &ctx) : Ctx(ctx) {}
49   AArch64MCCodeEmitter(const AArch64MCCodeEmitter &) = delete;
50   void operator=(const AArch64MCCodeEmitter &) = delete;
51   ~AArch64MCCodeEmitter() override = default;
52 
53   // getBinaryCodeForInstr - TableGen'erated function for getting the
54   // binary encoding for an instruction.
55   uint64_t getBinaryCodeForInstr(const MCInst &MI,
56                                  SmallVectorImpl<MCFixup> &Fixups,
57                                  const MCSubtargetInfo &STI) const;
58 
59   /// getMachineOpValue - Return binary encoding of operand. If the machine
60   /// operand requires relocation, record the relocation and return zero.
61   unsigned getMachineOpValue(const MCInst &MI, const MCOperand &MO,
62                              SmallVectorImpl<MCFixup> &Fixups,
63                              const MCSubtargetInfo &STI) const;
64 
65   /// getLdStUImm12OpValue - Return encoding info for 12-bit unsigned immediate
66   /// attached to a load, store or prfm instruction. If operand requires a
67   /// relocation, record it and return zero in that part of the encoding.
68   template <uint32_t FixupKind>
69   uint32_t getLdStUImm12OpValue(const MCInst &MI, unsigned OpIdx,
70                                 SmallVectorImpl<MCFixup> &Fixups,
71                                 const MCSubtargetInfo &STI) const;
72 
73   /// getAdrLabelOpValue - Return encoding info for 21-bit immediate ADR label
74   /// target.
75   uint32_t getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
76                               SmallVectorImpl<MCFixup> &Fixups,
77                               const MCSubtargetInfo &STI) const;
78 
79   /// getAddSubImmOpValue - Return encoding for the 12-bit immediate value and
80   /// the 2-bit shift field.
81   uint32_t getAddSubImmOpValue(const MCInst &MI, unsigned OpIdx,
82                                SmallVectorImpl<MCFixup> &Fixups,
83                                const MCSubtargetInfo &STI) const;
84 
85   /// getCondBranchTargetOpValue - Return the encoded value for a conditional
86   /// branch target.
87   uint32_t getCondBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
88                                       SmallVectorImpl<MCFixup> &Fixups,
89                                       const MCSubtargetInfo &STI) const;
90 
91   /// getPAuthPCRelOpValue - Return the encoded value for a pointer
92   /// authentication pc-relative operand.
93   uint32_t getPAuthPCRelOpValue(const MCInst &MI, unsigned OpIdx,
94                                 SmallVectorImpl<MCFixup> &Fixups,
95                                 const MCSubtargetInfo &STI) const;
96 
97   /// getLoadLiteralOpValue - Return the encoded value for a load-literal
98   /// pc-relative address.
99   uint32_t getLoadLiteralOpValue(const MCInst &MI, unsigned OpIdx,
100                                  SmallVectorImpl<MCFixup> &Fixups,
101                                  const MCSubtargetInfo &STI) const;
102 
103   /// getMemExtendOpValue - Return the encoded value for a reg-extend load/store
104   /// instruction: bit 0 is whether a shift is present, bit 1 is whether the
105   /// operation is a sign extend (as opposed to a zero extend).
106   uint32_t getMemExtendOpValue(const MCInst &MI, unsigned OpIdx,
107                                SmallVectorImpl<MCFixup> &Fixups,
108                                const MCSubtargetInfo &STI) const;
109 
110   /// getTestBranchTargetOpValue - Return the encoded value for a test-bit-and-
111   /// branch target.
112   uint32_t getTestBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
113                                       SmallVectorImpl<MCFixup> &Fixups,
114                                       const MCSubtargetInfo &STI) const;
115 
116   /// getBranchTargetOpValue - Return the encoded value for an unconditional
117   /// branch target.
118   uint32_t getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
119                                   SmallVectorImpl<MCFixup> &Fixups,
120                                   const MCSubtargetInfo &STI) const;
121 
122   /// getMoveWideImmOpValue - Return the encoded value for the immediate operand
123   /// of a MOVZ or MOVK instruction.
124   uint32_t getMoveWideImmOpValue(const MCInst &MI, unsigned OpIdx,
125                                  SmallVectorImpl<MCFixup> &Fixups,
126                                  const MCSubtargetInfo &STI) const;
127 
128   /// getVecShifterOpValue - Return the encoded value for the vector shifter.
129   uint32_t getVecShifterOpValue(const MCInst &MI, unsigned OpIdx,
130                                 SmallVectorImpl<MCFixup> &Fixups,
131                                 const MCSubtargetInfo &STI) const;
132 
133   /// getMoveVecShifterOpValue - Return the encoded value for the vector move
134   /// shifter (MSL).
135   uint32_t getMoveVecShifterOpValue(const MCInst &MI, unsigned OpIdx,
136                                     SmallVectorImpl<MCFixup> &Fixups,
137                                     const MCSubtargetInfo &STI) const;
138 
139   /// getFixedPointScaleOpValue - Return the encoded value for the
140   // FP-to-fixed-point scale factor.
141   uint32_t getFixedPointScaleOpValue(const MCInst &MI, unsigned OpIdx,
142                                      SmallVectorImpl<MCFixup> &Fixups,
143                                      const MCSubtargetInfo &STI) const;
144 
145   uint32_t getVecShiftR64OpValue(const MCInst &MI, unsigned OpIdx,
146                                  SmallVectorImpl<MCFixup> &Fixups,
147                                  const MCSubtargetInfo &STI) const;
148   uint32_t getVecShiftR32OpValue(const MCInst &MI, unsigned OpIdx,
149                                  SmallVectorImpl<MCFixup> &Fixups,
150                                  const MCSubtargetInfo &STI) const;
151   uint32_t getVecShiftR16OpValue(const MCInst &MI, unsigned OpIdx,
152                                  SmallVectorImpl<MCFixup> &Fixups,
153                                  const MCSubtargetInfo &STI) const;
154   uint32_t getVecShiftR8OpValue(const MCInst &MI, unsigned OpIdx,
155                                 SmallVectorImpl<MCFixup> &Fixups,
156                                 const MCSubtargetInfo &STI) const;
157   uint32_t getVecShiftL64OpValue(const MCInst &MI, unsigned OpIdx,
158                                  SmallVectorImpl<MCFixup> &Fixups,
159                                  const MCSubtargetInfo &STI) const;
160   uint32_t getVecShiftL32OpValue(const MCInst &MI, unsigned OpIdx,
161                                  SmallVectorImpl<MCFixup> &Fixups,
162                                  const MCSubtargetInfo &STI) const;
163   uint32_t getVecShiftL16OpValue(const MCInst &MI, unsigned OpIdx,
164                                  SmallVectorImpl<MCFixup> &Fixups,
165                                  const MCSubtargetInfo &STI) const;
166   uint32_t getVecShiftL8OpValue(const MCInst &MI, unsigned OpIdx,
167                                 SmallVectorImpl<MCFixup> &Fixups,
168                                 const MCSubtargetInfo &STI) const;
169 
170   uint32_t getImm8OptLsl(const MCInst &MI, unsigned OpIdx,
171                          SmallVectorImpl<MCFixup> &Fixups,
172                          const MCSubtargetInfo &STI) const;
173   uint32_t getSVEIncDecImm(const MCInst &MI, unsigned OpIdx,
174                            SmallVectorImpl<MCFixup> &Fixups,
175                            const MCSubtargetInfo &STI) const;
176 
177   unsigned fixMOVZ(const MCInst &MI, unsigned EncodedValue,
178                    const MCSubtargetInfo &STI) const;
179 
180   void encodeInstruction(const MCInst &MI, SmallVectorImpl<char> &CB,
181                          SmallVectorImpl<MCFixup> &Fixups,
182                          const MCSubtargetInfo &STI) const override;
183 
184   unsigned fixMulHigh(const MCInst &MI, unsigned EncodedValue,
185                       const MCSubtargetInfo &STI) const;
186 
187   template<int hasRs, int hasRt2> unsigned
188   fixLoadStoreExclusive(const MCInst &MI, unsigned EncodedValue,
189                         const MCSubtargetInfo &STI) const;
190 
191   unsigned fixOneOperandFPComparison(const MCInst &MI, unsigned EncodedValue,
192                                      const MCSubtargetInfo &STI) const;
193 
194   template <unsigned Multiple>
195   uint32_t EncodeRegAsMultipleOf(const MCInst &MI, unsigned OpIdx,
196                                  SmallVectorImpl<MCFixup> &Fixups,
197                                  const MCSubtargetInfo &STI) const;
198   uint32_t EncodePNR_p8to15(const MCInst &MI, unsigned OpIdx,
199                             SmallVectorImpl<MCFixup> &Fixups,
200                             const MCSubtargetInfo &STI) const;
201 
202   uint32_t EncodeZPR2StridedRegisterClass(const MCInst &MI, unsigned OpIdx,
203                                           SmallVectorImpl<MCFixup> &Fixups,
204                                           const MCSubtargetInfo &STI) const;
205   uint32_t EncodeZPR4StridedRegisterClass(const MCInst &MI, unsigned OpIdx,
206                                           SmallVectorImpl<MCFixup> &Fixups,
207                                           const MCSubtargetInfo &STI) const;
208 
209   uint32_t EncodeMatrixTileListRegisterClass(const MCInst &MI, unsigned OpIdx,
210                                              SmallVectorImpl<MCFixup> &Fixups,
211                                              const MCSubtargetInfo &STI) const;
212   template <unsigned BaseReg>
213   uint32_t encodeMatrixIndexGPR32(const MCInst &MI, unsigned OpIdx,
214                                   SmallVectorImpl<MCFixup> &Fixups,
215                                   const MCSubtargetInfo &STI) const;
216 };
217 
218 } // end anonymous namespace
219 
220 /// getMachineOpValue - Return binary encoding of operand. If the machine
221 /// operand requires relocation, record the relocation and return zero.
222 unsigned
223 AArch64MCCodeEmitter::getMachineOpValue(const MCInst &MI, const MCOperand &MO,
224                                         SmallVectorImpl<MCFixup> &Fixups,
225                                         const MCSubtargetInfo &STI) const {
226   if (MO.isReg())
227     return Ctx.getRegisterInfo()->getEncodingValue(MO.getReg());
228 
229   assert(MO.isImm() && "did not expect relocated expression");
230   return static_cast<unsigned>(MO.getImm());
231 }
232 
233 template<unsigned FixupKind> uint32_t
234 AArch64MCCodeEmitter::getLdStUImm12OpValue(const MCInst &MI, unsigned OpIdx,
235                                            SmallVectorImpl<MCFixup> &Fixups,
236                                            const MCSubtargetInfo &STI) const {
237   const MCOperand &MO = MI.getOperand(OpIdx);
238   uint32_t ImmVal = 0;
239 
240   if (MO.isImm())
241     ImmVal = static_cast<uint32_t>(MO.getImm());
242   else {
243     assert(MO.isExpr() && "unable to encode load/store imm operand");
244     MCFixupKind Kind = MCFixupKind(FixupKind);
245     Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
246     ++MCNumFixups;
247   }
248 
249   return ImmVal;
250 }
251 
252 /// getAdrLabelOpValue - Return encoding info for 21-bit immediate ADR label
253 /// target.
254 uint32_t
255 AArch64MCCodeEmitter::getAdrLabelOpValue(const MCInst &MI, unsigned OpIdx,
256                                          SmallVectorImpl<MCFixup> &Fixups,
257                                          const MCSubtargetInfo &STI) const {
258   const MCOperand &MO = MI.getOperand(OpIdx);
259 
260   // If the destination is an immediate, we have nothing to do.
261   if (MO.isImm())
262     return MO.getImm();
263   assert(MO.isExpr() && "Unexpected target type!");
264   const MCExpr *Expr = MO.getExpr();
265 
266   MCFixupKind Kind = MI.getOpcode() == AArch64::ADR
267                          ? MCFixupKind(AArch64::fixup_aarch64_pcrel_adr_imm21)
268                          : MCFixupKind(AArch64::fixup_aarch64_pcrel_adrp_imm21);
269   Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
270 
271   MCNumFixups += 1;
272 
273   // All of the information is in the fixup.
274   return 0;
275 }
276 
277 /// getAddSubImmOpValue - Return encoding for the 12-bit immediate value and
278 /// the 2-bit shift field.  The shift field is stored in bits 13-14 of the
279 /// return value.
280 uint32_t
281 AArch64MCCodeEmitter::getAddSubImmOpValue(const MCInst &MI, unsigned OpIdx,
282                                           SmallVectorImpl<MCFixup> &Fixups,
283                                           const MCSubtargetInfo &STI) const {
284   // Suboperands are [imm, shifter].
285   const MCOperand &MO = MI.getOperand(OpIdx);
286   const MCOperand &MO1 = MI.getOperand(OpIdx + 1);
287   assert(AArch64_AM::getShiftType(MO1.getImm()) == AArch64_AM::LSL &&
288          "unexpected shift type for add/sub immediate");
289   unsigned ShiftVal = AArch64_AM::getShiftValue(MO1.getImm());
290   assert((ShiftVal == 0 || ShiftVal == 12) &&
291          "unexpected shift value for add/sub immediate");
292   if (MO.isImm())
293     return MO.getImm() | (ShiftVal == 0 ? 0 : (1 << ShiftVal));
294   assert(MO.isExpr() && "Unable to encode MCOperand!");
295   const MCExpr *Expr = MO.getExpr();
296 
297   // Encode the 12 bits of the fixup.
298   MCFixupKind Kind = MCFixupKind(AArch64::fixup_aarch64_add_imm12);
299   Fixups.push_back(MCFixup::create(0, Expr, Kind, MI.getLoc()));
300 
301   ++MCNumFixups;
302 
303   // Set the shift bit of the add instruction for relocation types
304   // R_AARCH64_TLSLE_ADD_TPREL_HI12 and R_AARCH64_TLSLD_ADD_DTPREL_HI12.
305   if (const AArch64MCExpr *A64E = dyn_cast<AArch64MCExpr>(Expr)) {
306     AArch64MCExpr::VariantKind RefKind = A64E->getKind();
307     if (RefKind == AArch64MCExpr::VK_TPREL_HI12 ||
308         RefKind == AArch64MCExpr::VK_DTPREL_HI12 ||
309         RefKind == AArch64MCExpr::VK_SECREL_HI12)
310       ShiftVal = 12;
311   }
312   return ShiftVal == 0 ? 0 : (1 << ShiftVal);
313 }
314 
315 /// getCondBranchTargetOpValue - Return the encoded value for a conditional
316 /// branch target.
317 uint32_t AArch64MCCodeEmitter::getCondBranchTargetOpValue(
318     const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
319     const MCSubtargetInfo &STI) const {
320   const MCOperand &MO = MI.getOperand(OpIdx);
321 
322   // If the destination is an immediate, we have nothing to do.
323   if (MO.isImm())
324     return MO.getImm();
325   assert(MO.isExpr() && "Unexpected target type!");
326 
327   MCFixupKind Kind = MCFixupKind(AArch64::fixup_aarch64_pcrel_branch19);
328   Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
329 
330   ++MCNumFixups;
331 
332   // All of the information is in the fixup.
333   return 0;
334 }
335 
336 /// getPAuthPCRelOpValue - Return the encoded value for a pointer
337 /// authentication pc-relative operand.
338 uint32_t
339 AArch64MCCodeEmitter::getPAuthPCRelOpValue(const MCInst &MI, unsigned OpIdx,
340                                            SmallVectorImpl<MCFixup> &Fixups,
341                                            const MCSubtargetInfo &STI) const {
342   const MCOperand &MO = MI.getOperand(OpIdx);
343 
344   // If the destination is an immediate, invert sign as it's a negative value
345   // that should be encoded as unsigned
346   if (MO.isImm())
347     return -(MO.getImm());
348   assert(MO.isExpr() && "Unexpected target type!");
349 
350   MCFixupKind Kind = MCFixupKind(AArch64::fixup_aarch64_pcrel_branch16);
351   Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
352 
353   ++MCNumFixups;
354 
355   // All of the information is in the fixup.
356   return 0;
357 }
358 
359 /// getLoadLiteralOpValue - Return the encoded value for a load-literal
360 /// pc-relative address.
361 uint32_t
362 AArch64MCCodeEmitter::getLoadLiteralOpValue(const MCInst &MI, unsigned OpIdx,
363                                             SmallVectorImpl<MCFixup> &Fixups,
364                                             const MCSubtargetInfo &STI) const {
365   const MCOperand &MO = MI.getOperand(OpIdx);
366 
367   // If the destination is an immediate, we have nothing to do.
368   if (MO.isImm())
369     return MO.getImm();
370   assert(MO.isExpr() && "Unexpected target type!");
371 
372   MCFixupKind Kind = MCFixupKind(AArch64::fixup_aarch64_ldr_pcrel_imm19);
373   Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
374 
375   ++MCNumFixups;
376 
377   // All of the information is in the fixup.
378   return 0;
379 }
380 
381 uint32_t
382 AArch64MCCodeEmitter::getMemExtendOpValue(const MCInst &MI, unsigned OpIdx,
383                                           SmallVectorImpl<MCFixup> &Fixups,
384                                           const MCSubtargetInfo &STI) const {
385   unsigned SignExtend = MI.getOperand(OpIdx).getImm();
386   unsigned DoShift = MI.getOperand(OpIdx + 1).getImm();
387   return (SignExtend << 1) | DoShift;
388 }
389 
390 uint32_t
391 AArch64MCCodeEmitter::getMoveWideImmOpValue(const MCInst &MI, unsigned OpIdx,
392                                             SmallVectorImpl<MCFixup> &Fixups,
393                                             const MCSubtargetInfo &STI) const {
394   const MCOperand &MO = MI.getOperand(OpIdx);
395 
396   if (MO.isImm())
397     return MO.getImm();
398   assert(MO.isExpr() && "Unexpected movz/movk immediate");
399 
400   Fixups.push_back(MCFixup::create(
401       0, MO.getExpr(), MCFixupKind(AArch64::fixup_aarch64_movw), MI.getLoc()));
402 
403   ++MCNumFixups;
404 
405   return 0;
406 }
407 
408 /// getTestBranchTargetOpValue - Return the encoded value for a test-bit-and-
409 /// branch target.
410 uint32_t AArch64MCCodeEmitter::getTestBranchTargetOpValue(
411     const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
412     const MCSubtargetInfo &STI) const {
413   const MCOperand &MO = MI.getOperand(OpIdx);
414 
415   // If the destination is an immediate, we have nothing to do.
416   if (MO.isImm())
417     return MO.getImm();
418   assert(MO.isExpr() && "Unexpected ADR target type!");
419 
420   MCFixupKind Kind = MCFixupKind(AArch64::fixup_aarch64_pcrel_branch14);
421   Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
422 
423   ++MCNumFixups;
424 
425   // All of the information is in the fixup.
426   return 0;
427 }
428 
429 /// getBranchTargetOpValue - Return the encoded value for an unconditional
430 /// branch target.
431 uint32_t
432 AArch64MCCodeEmitter::getBranchTargetOpValue(const MCInst &MI, unsigned OpIdx,
433                                              SmallVectorImpl<MCFixup> &Fixups,
434                                              const MCSubtargetInfo &STI) const {
435   const MCOperand &MO = MI.getOperand(OpIdx);
436 
437   // If the destination is an immediate, we have nothing to do.
438   if (MO.isImm())
439     return MO.getImm();
440   assert(MO.isExpr() && "Unexpected ADR target type!");
441 
442   MCFixupKind Kind = MI.getOpcode() == AArch64::BL
443                          ? MCFixupKind(AArch64::fixup_aarch64_pcrel_call26)
444                          : MCFixupKind(AArch64::fixup_aarch64_pcrel_branch26);
445   Fixups.push_back(MCFixup::create(0, MO.getExpr(), Kind, MI.getLoc()));
446 
447   ++MCNumFixups;
448 
449   // All of the information is in the fixup.
450   return 0;
451 }
452 
453 /// getVecShifterOpValue - Return the encoded value for the vector shifter:
454 ///
455 ///   00 -> 0
456 ///   01 -> 8
457 ///   10 -> 16
458 ///   11 -> 24
459 uint32_t
460 AArch64MCCodeEmitter::getVecShifterOpValue(const MCInst &MI, unsigned OpIdx,
461                                            SmallVectorImpl<MCFixup> &Fixups,
462                                            const MCSubtargetInfo &STI) const {
463   const MCOperand &MO = MI.getOperand(OpIdx);
464   assert(MO.isImm() && "Expected an immediate value for the shift amount!");
465 
466   switch (MO.getImm()) {
467   default:
468     break;
469   case 0:
470     return 0;
471   case 8:
472     return 1;
473   case 16:
474     return 2;
475   case 24:
476     return 3;
477   }
478 
479   llvm_unreachable("Invalid value for vector shift amount!");
480 }
481 
482 /// getFixedPointScaleOpValue - Return the encoded value for the
483 // FP-to-fixed-point scale factor.
484 uint32_t AArch64MCCodeEmitter::getFixedPointScaleOpValue(
485     const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
486     const MCSubtargetInfo &STI) const {
487   const MCOperand &MO = MI.getOperand(OpIdx);
488   assert(MO.isImm() && "Expected an immediate value for the scale amount!");
489   return 64 - MO.getImm();
490 }
491 
492 uint32_t
493 AArch64MCCodeEmitter::getVecShiftR64OpValue(const MCInst &MI, unsigned OpIdx,
494                                             SmallVectorImpl<MCFixup> &Fixups,
495                                             const MCSubtargetInfo &STI) const {
496   const MCOperand &MO = MI.getOperand(OpIdx);
497   assert(MO.isImm() && "Expected an immediate value for the scale amount!");
498   return 64 - MO.getImm();
499 }
500 
501 uint32_t
502 AArch64MCCodeEmitter::getVecShiftR32OpValue(const MCInst &MI, unsigned OpIdx,
503                                             SmallVectorImpl<MCFixup> &Fixups,
504                                             const MCSubtargetInfo &STI) const {
505   const MCOperand &MO = MI.getOperand(OpIdx);
506   assert(MO.isImm() && "Expected an immediate value for the scale amount!");
507   return 32 - MO.getImm();
508 }
509 
510 uint32_t
511 AArch64MCCodeEmitter::getVecShiftR16OpValue(const MCInst &MI, unsigned OpIdx,
512                                             SmallVectorImpl<MCFixup> &Fixups,
513                                             const MCSubtargetInfo &STI) const {
514   const MCOperand &MO = MI.getOperand(OpIdx);
515   assert(MO.isImm() && "Expected an immediate value for the scale amount!");
516   return 16 - MO.getImm();
517 }
518 
519 uint32_t
520 AArch64MCCodeEmitter::getVecShiftR8OpValue(const MCInst &MI, unsigned OpIdx,
521                                            SmallVectorImpl<MCFixup> &Fixups,
522                                            const MCSubtargetInfo &STI) const {
523   const MCOperand &MO = MI.getOperand(OpIdx);
524   assert(MO.isImm() && "Expected an immediate value for the scale amount!");
525   return 8 - MO.getImm();
526 }
527 
528 uint32_t
529 AArch64MCCodeEmitter::getVecShiftL64OpValue(const MCInst &MI, unsigned OpIdx,
530                                             SmallVectorImpl<MCFixup> &Fixups,
531                                             const MCSubtargetInfo &STI) const {
532   const MCOperand &MO = MI.getOperand(OpIdx);
533   assert(MO.isImm() && "Expected an immediate value for the scale amount!");
534   return MO.getImm() - 64;
535 }
536 
537 uint32_t
538 AArch64MCCodeEmitter::getVecShiftL32OpValue(const MCInst &MI, unsigned OpIdx,
539                                             SmallVectorImpl<MCFixup> &Fixups,
540                                             const MCSubtargetInfo &STI) const {
541   const MCOperand &MO = MI.getOperand(OpIdx);
542   assert(MO.isImm() && "Expected an immediate value for the scale amount!");
543   return MO.getImm() - 32;
544 }
545 
546 uint32_t
547 AArch64MCCodeEmitter::getVecShiftL16OpValue(const MCInst &MI, unsigned OpIdx,
548                                             SmallVectorImpl<MCFixup> &Fixups,
549                                             const MCSubtargetInfo &STI) const {
550   const MCOperand &MO = MI.getOperand(OpIdx);
551   assert(MO.isImm() && "Expected an immediate value for the scale amount!");
552   return MO.getImm() - 16;
553 }
554 
555 uint32_t
556 AArch64MCCodeEmitter::getVecShiftL8OpValue(const MCInst &MI, unsigned OpIdx,
557                                            SmallVectorImpl<MCFixup> &Fixups,
558                                            const MCSubtargetInfo &STI) const {
559   const MCOperand &MO = MI.getOperand(OpIdx);
560   assert(MO.isImm() && "Expected an immediate value for the scale amount!");
561   return MO.getImm() - 8;
562 }
563 
564 template <unsigned Multiple>
565 uint32_t
566 AArch64MCCodeEmitter::EncodeRegAsMultipleOf(const MCInst &MI, unsigned OpIdx,
567                                             SmallVectorImpl<MCFixup> &Fixups,
568                                             const MCSubtargetInfo &STI) const {
569   assert(llvm::isPowerOf2_32(Multiple) && "Multiple is not a power of 2");
570   auto RegOpnd = MI.getOperand(OpIdx).getReg();
571   unsigned RegVal = Ctx.getRegisterInfo()->getEncodingValue(RegOpnd);
572   return RegVal / Multiple;
573 }
574 
575 uint32_t
576 AArch64MCCodeEmitter::EncodePNR_p8to15(const MCInst &MI, unsigned OpIdx,
577                                        SmallVectorImpl<MCFixup> &Fixups,
578                                        const MCSubtargetInfo &STI) const {
579   auto RegOpnd = MI.getOperand(OpIdx).getReg();
580   return RegOpnd - AArch64::PN8;
581 }
582 
583 uint32_t AArch64MCCodeEmitter::EncodeZPR2StridedRegisterClass(
584     const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
585     const MCSubtargetInfo &STI) const {
586   auto RegOpnd = MI.getOperand(OpIdx).getReg();
587   unsigned RegVal = Ctx.getRegisterInfo()->getEncodingValue(RegOpnd);
588   unsigned T = (RegVal & 0x10) >> 1;
589   unsigned Zt = RegVal & 0x7;
590   return T | Zt;
591 }
592 
593 uint32_t AArch64MCCodeEmitter::EncodeZPR4StridedRegisterClass(
594     const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
595     const MCSubtargetInfo &STI) const {
596   auto RegOpnd = MI.getOperand(OpIdx).getReg();
597   unsigned RegVal = Ctx.getRegisterInfo()->getEncodingValue(RegOpnd);
598   unsigned T = (RegVal & 0x10) >> 2;
599   unsigned Zt = RegVal & 0x3;
600   return T | Zt;
601 }
602 
603 uint32_t AArch64MCCodeEmitter::EncodeMatrixTileListRegisterClass(
604     const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
605     const MCSubtargetInfo &STI) const {
606   unsigned RegMask = MI.getOperand(OpIdx).getImm();
607   assert(RegMask <= 0xFF && "Invalid register mask!");
608   return RegMask;
609 }
610 
611 template <unsigned BaseReg>
612 uint32_t
613 AArch64MCCodeEmitter::encodeMatrixIndexGPR32(const MCInst &MI, unsigned OpIdx,
614                                              SmallVectorImpl<MCFixup> &Fixups,
615                                              const MCSubtargetInfo &STI) const {
616   auto RegOpnd = MI.getOperand(OpIdx).getReg();
617   return RegOpnd - BaseReg;
618 }
619 
620 uint32_t
621 AArch64MCCodeEmitter::getImm8OptLsl(const MCInst &MI, unsigned OpIdx,
622                                     SmallVectorImpl<MCFixup> &Fixups,
623                                     const MCSubtargetInfo &STI) const {
624   // Test shift
625   auto ShiftOpnd = MI.getOperand(OpIdx + 1).getImm();
626   assert(AArch64_AM::getShiftType(ShiftOpnd) == AArch64_AM::LSL &&
627          "Unexpected shift type for imm8_opt_lsl immediate.");
628 
629   unsigned ShiftVal = AArch64_AM::getShiftValue(ShiftOpnd);
630   assert((ShiftVal == 0 || ShiftVal == 8) &&
631          "Unexpected shift value for imm8_opt_lsl immediate.");
632 
633   // Test immediate
634   auto Immediate = MI.getOperand(OpIdx).getImm();
635   return (Immediate & 0xff) | (ShiftVal == 0 ? 0 : (1 << ShiftVal));
636 }
637 
638 uint32_t
639 AArch64MCCodeEmitter::getSVEIncDecImm(const MCInst &MI, unsigned OpIdx,
640                                            SmallVectorImpl<MCFixup> &Fixups,
641                                            const MCSubtargetInfo &STI) const {
642   const MCOperand &MO = MI.getOperand(OpIdx);
643   assert(MO.isImm() && "Expected an immediate value!");
644   // Normalize 1-16 range to 0-15.
645   return MO.getImm() - 1;
646 }
647 
648 /// getMoveVecShifterOpValue - Return the encoded value for the vector move
649 /// shifter (MSL).
650 uint32_t AArch64MCCodeEmitter::getMoveVecShifterOpValue(
651     const MCInst &MI, unsigned OpIdx, SmallVectorImpl<MCFixup> &Fixups,
652     const MCSubtargetInfo &STI) const {
653   const MCOperand &MO = MI.getOperand(OpIdx);
654   assert(MO.isImm() &&
655          "Expected an immediate value for the move shift amount!");
656   unsigned ShiftVal = AArch64_AM::getShiftValue(MO.getImm());
657   assert((ShiftVal == 8 || ShiftVal == 16) && "Invalid shift amount!");
658   return ShiftVal == 8 ? 0 : 1;
659 }
660 
661 unsigned AArch64MCCodeEmitter::fixMOVZ(const MCInst &MI, unsigned EncodedValue,
662                                        const MCSubtargetInfo &STI) const {
663   // If one of the signed fixup kinds is applied to a MOVZ instruction, the
664   // eventual result could be either a MOVZ or a MOVN. It's the MCCodeEmitter's
665   // job to ensure that any bits possibly affected by this are 0. This means we
666   // must zero out bit 30 (essentially emitting a MOVN).
667   MCOperand UImm16MO = MI.getOperand(1);
668 
669   // Nothing to do if there's no fixup.
670   if (UImm16MO.isImm())
671     return EncodedValue;
672 
673   const MCExpr *E = UImm16MO.getExpr();
674   if (const AArch64MCExpr *A64E = dyn_cast<AArch64MCExpr>(E)) {
675     switch (A64E->getKind()) {
676     case AArch64MCExpr::VK_DTPREL_G2:
677     case AArch64MCExpr::VK_DTPREL_G1:
678     case AArch64MCExpr::VK_DTPREL_G0:
679     case AArch64MCExpr::VK_GOTTPREL_G1:
680     case AArch64MCExpr::VK_TPREL_G2:
681     case AArch64MCExpr::VK_TPREL_G1:
682     case AArch64MCExpr::VK_TPREL_G0:
683       return EncodedValue & ~(1u << 30);
684     default:
685       // Nothing to do for an unsigned fixup.
686       return EncodedValue;
687     }
688   }
689 
690   return EncodedValue;
691 }
692 
693 void AArch64MCCodeEmitter::encodeInstruction(const MCInst &MI,
694                                              SmallVectorImpl<char> &CB,
695 
696                                              SmallVectorImpl<MCFixup> &Fixups,
697                                              const MCSubtargetInfo &STI) const {
698   if (MI.getOpcode() == AArch64::TLSDESCCALL) {
699     // This is a directive which applies an R_AARCH64_TLSDESC_CALL to the
700     // following (BLR) instruction. It doesn't emit any code itself so it
701     // doesn't go through the normal TableGenerated channels.
702     auto Reloc = STI.getTargetTriple().getEnvironment() == Triple::GNUILP32
703                      ? ELF::R_AARCH64_P32_TLSDESC_CALL
704                      : ELF::R_AARCH64_TLSDESC_CALL;
705     Fixups.push_back(
706         MCFixup::create(0, MI.getOperand(0).getExpr(),
707                         MCFixupKind(FirstLiteralRelocationKind + Reloc)));
708     return;
709   }
710 
711   if (MI.getOpcode() == AArch64::SPACE) {
712     // SPACE just increases basic block size, in both cases no actual code.
713     return;
714   }
715 
716   uint64_t Binary = getBinaryCodeForInstr(MI, Fixups, STI);
717   support::endian::write<uint32_t>(CB, Binary, llvm::endianness::little);
718   ++MCNumEmitted; // Keep track of the # of mi's emitted.
719 }
720 
721 unsigned
722 AArch64MCCodeEmitter::fixMulHigh(const MCInst &MI,
723                                  unsigned EncodedValue,
724                                  const MCSubtargetInfo &STI) const {
725   // The Ra field of SMULH and UMULH is unused: it should be assembled as 31
726   // (i.e. all bits 1) but is ignored by the processor.
727   EncodedValue |= 0x1f << 10;
728   return EncodedValue;
729 }
730 
731 template<int hasRs, int hasRt2> unsigned
732 AArch64MCCodeEmitter::fixLoadStoreExclusive(const MCInst &MI,
733                                             unsigned EncodedValue,
734                                             const MCSubtargetInfo &STI) const {
735   if (!hasRs) EncodedValue |= 0x001F0000;
736   if (!hasRt2) EncodedValue |= 0x00007C00;
737 
738   return EncodedValue;
739 }
740 
741 unsigned AArch64MCCodeEmitter::fixOneOperandFPComparison(
742     const MCInst &MI, unsigned EncodedValue, const MCSubtargetInfo &STI) const {
743   // The Rm field of FCMP and friends is unused - it should be assembled
744   // as 0, but is ignored by the processor.
745   EncodedValue &= ~(0x1f << 16);
746   return EncodedValue;
747 }
748 
749 #include "AArch64GenMCCodeEmitter.inc"
750 
751 MCCodeEmitter *llvm::createAArch64MCCodeEmitter(const MCInstrInfo &MCII,
752                                                 MCContext &Ctx) {
753   return new AArch64MCCodeEmitter(MCII, Ctx);
754 }
755