xref: /llvm-project/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp (revision 1e32550de6354f4cc618d48c7a7a046f895cb544)
1 //===-- AMDGPUDisassembler.cpp - Disassembler for AMDGPU ISA --------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 //===----------------------------------------------------------------------===//
11 //
12 /// \file
13 ///
14 /// This file contains definition for AMDGPU ISA disassembler
15 //
16 //===----------------------------------------------------------------------===//
17 
18 // ToDo: What to do with instruction suffixes (v_mov_b32 vs v_mov_b32_e32)?
19 
20 #include "AMDGPUDisassembler.h"
21 #include "AMDGPU.h"
22 #include "AMDGPURegisterInfo.h"
23 #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
24 #include "SIDefines.h"
25 #include "Utils/AMDGPUBaseInfo.h"
26 
27 #include "llvm/BinaryFormat/ELF.h"
28 #include "llvm/MC/MCContext.h"
29 #include "llvm/MC/MCFixedLenDisassembler.h"
30 #include "llvm/MC/MCInst.h"
31 #include "llvm/MC/MCInstrDesc.h"
32 #include "llvm/MC/MCSubtargetInfo.h"
33 #include "llvm/Support/Debug.h"
34 #include "llvm/Support/Endian.h"
35 #include "llvm/Support/TargetRegistry.h"
36 
37 using namespace llvm;
38 
39 #define DEBUG_TYPE "amdgpu-disassembler"
40 
41 typedef llvm::MCDisassembler::DecodeStatus DecodeStatus;
42 
43 
44 inline static MCDisassembler::DecodeStatus
45 addOperand(MCInst &Inst, const MCOperand& Opnd) {
46   Inst.addOperand(Opnd);
47   return Opnd.isValid() ?
48     MCDisassembler::Success :
49     MCDisassembler::SoftFail;
50 }
51 
52 static int insertNamedMCOperand(MCInst &MI, const MCOperand &Op,
53                                 uint16_t NameIdx) {
54   int OpIdx = AMDGPU::getNamedOperandIdx(MI.getOpcode(), NameIdx);
55   if (OpIdx != -1) {
56     auto I = MI.begin();
57     std::advance(I, OpIdx);
58     MI.insert(I, Op);
59   }
60   return OpIdx;
61 }
62 
63 static DecodeStatus decodeSoppBrTarget(MCInst &Inst, unsigned Imm,
64                                        uint64_t Addr, const void *Decoder) {
65   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder);
66 
67   APInt SignedOffset(18, Imm * 4, true);
68   int64_t Offset = (SignedOffset.sext(64) + 4 + Addr).getSExtValue();
69 
70   if (DAsm->tryAddingSymbolicOperand(Inst, Offset, Addr, true, 2, 2))
71     return MCDisassembler::Success;
72   return addOperand(Inst, MCOperand::createImm(Imm));
73 }
74 
75 #define DECODE_OPERAND(StaticDecoderName, DecoderName) \
76 static DecodeStatus StaticDecoderName(MCInst &Inst, \
77                                        unsigned Imm, \
78                                        uint64_t /*Addr*/, \
79                                        const void *Decoder) { \
80   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder); \
81   return addOperand(Inst, DAsm->DecoderName(Imm)); \
82 }
83 
84 #define DECODE_OPERAND_REG(RegClass) \
85 DECODE_OPERAND(Decode##RegClass##RegisterClass, decodeOperand_##RegClass)
86 
87 DECODE_OPERAND_REG(VGPR_32)
88 DECODE_OPERAND_REG(VS_32)
89 DECODE_OPERAND_REG(VS_64)
90 DECODE_OPERAND_REG(VS_128)
91 
92 DECODE_OPERAND_REG(VReg_64)
93 DECODE_OPERAND_REG(VReg_96)
94 DECODE_OPERAND_REG(VReg_128)
95 
96 DECODE_OPERAND_REG(SReg_32)
97 DECODE_OPERAND_REG(SReg_32_XM0_XEXEC)
98 DECODE_OPERAND_REG(SReg_32_XEXEC_HI)
99 DECODE_OPERAND_REG(SReg_64)
100 DECODE_OPERAND_REG(SReg_64_XEXEC)
101 DECODE_OPERAND_REG(SReg_128)
102 DECODE_OPERAND_REG(SReg_256)
103 DECODE_OPERAND_REG(SReg_512)
104 
105 
106 static DecodeStatus decodeOperand_VSrc16(MCInst &Inst,
107                                          unsigned Imm,
108                                          uint64_t Addr,
109                                          const void *Decoder) {
110   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder);
111   return addOperand(Inst, DAsm->decodeOperand_VSrc16(Imm));
112 }
113 
114 static DecodeStatus decodeOperand_VSrcV216(MCInst &Inst,
115                                          unsigned Imm,
116                                          uint64_t Addr,
117                                          const void *Decoder) {
118   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder);
119   return addOperand(Inst, DAsm->decodeOperand_VSrcV216(Imm));
120 }
121 
122 #define DECODE_SDWA(DecName) \
123 DECODE_OPERAND(decodeSDWA##DecName, decodeSDWA##DecName)
124 
125 DECODE_SDWA(Src32)
126 DECODE_SDWA(Src16)
127 DECODE_SDWA(VopcDst)
128 
129 #include "AMDGPUGenDisassemblerTables.inc"
130 
131 //===----------------------------------------------------------------------===//
132 //
133 //===----------------------------------------------------------------------===//
134 
135 template <typename T> static inline T eatBytes(ArrayRef<uint8_t>& Bytes) {
136   assert(Bytes.size() >= sizeof(T));
137   const auto Res = support::endian::read<T, support::endianness::little>(Bytes.data());
138   Bytes = Bytes.slice(sizeof(T));
139   return Res;
140 }
141 
142 DecodeStatus AMDGPUDisassembler::tryDecodeInst(const uint8_t* Table,
143                                                MCInst &MI,
144                                                uint64_t Inst,
145                                                uint64_t Address) const {
146   assert(MI.getOpcode() == 0);
147   assert(MI.getNumOperands() == 0);
148   MCInst TmpInst;
149   HasLiteral = false;
150   const auto SavedBytes = Bytes;
151   if (decodeInstruction(Table, TmpInst, Inst, Address, this, STI)) {
152     MI = TmpInst;
153     return MCDisassembler::Success;
154   }
155   Bytes = SavedBytes;
156   return MCDisassembler::Fail;
157 }
158 
159 DecodeStatus AMDGPUDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
160                                                 ArrayRef<uint8_t> Bytes_,
161                                                 uint64_t Address,
162                                                 raw_ostream &WS,
163                                                 raw_ostream &CS) const {
164   CommentStream = &CS;
165   bool IsSDWA = false;
166 
167   // ToDo: AMDGPUDisassembler supports only VI ISA.
168   if (!STI.getFeatureBits()[AMDGPU::FeatureGCN3Encoding])
169     report_fatal_error("Disassembly not yet supported for subtarget");
170 
171   const unsigned MaxInstBytesNum = (std::min)((size_t)8, Bytes_.size());
172   Bytes = Bytes_.slice(0, MaxInstBytesNum);
173 
174   DecodeStatus Res = MCDisassembler::Fail;
175   do {
176     // ToDo: better to switch encoding length using some bit predicate
177     // but it is unknown yet, so try all we can
178 
179     // Try to decode DPP and SDWA first to solve conflict with VOP1 and VOP2
180     // encodings
181     if (Bytes.size() >= 8) {
182       const uint64_t QW = eatBytes<uint64_t>(Bytes);
183       Res = tryDecodeInst(DecoderTableDPP64, MI, QW, Address);
184       if (Res) break;
185 
186       Res = tryDecodeInst(DecoderTableSDWA64, MI, QW, Address);
187       if (Res) { IsSDWA = true;  break; }
188 
189       Res = tryDecodeInst(DecoderTableSDWA964, MI, QW, Address);
190       if (Res) { IsSDWA = true;  break; }
191     }
192 
193     // Reinitialize Bytes as DPP64 could have eaten too much
194     Bytes = Bytes_.slice(0, MaxInstBytesNum);
195 
196     // Try decode 32-bit instruction
197     if (Bytes.size() < 4) break;
198     const uint32_t DW = eatBytes<uint32_t>(Bytes);
199     Res = tryDecodeInst(DecoderTableVI32, MI, DW, Address);
200     if (Res) break;
201 
202     Res = tryDecodeInst(DecoderTableAMDGPU32, MI, DW, Address);
203     if (Res) break;
204 
205     if (Bytes.size() < 4) break;
206     const uint64_t QW = ((uint64_t)eatBytes<uint32_t>(Bytes) << 32) | DW;
207     Res = tryDecodeInst(DecoderTableVI64, MI, QW, Address);
208     if (Res) break;
209 
210     Res = tryDecodeInst(DecoderTableAMDGPU64, MI, QW, Address);
211     if (Res) break;
212 
213     Res = tryDecodeInst(DecoderTableGFX964, MI, QW, Address);
214   } while (false);
215 
216   if (Res && (MI.getOpcode() == AMDGPU::V_MAC_F32_e64_vi ||
217               MI.getOpcode() == AMDGPU::V_MAC_F32_e64_si ||
218               MI.getOpcode() == AMDGPU::V_MAC_F16_e64_vi)) {
219     // Insert dummy unused src2_modifiers.
220     insertNamedMCOperand(MI, MCOperand::createImm(0),
221                          AMDGPU::OpName::src2_modifiers);
222   }
223 
224   if (Res && IsSDWA)
225     Res = convertSDWAInst(MI);
226 
227   Size = Res ? (MaxInstBytesNum - Bytes.size()) : 0;
228   return Res;
229 }
230 
231 DecodeStatus AMDGPUDisassembler::convertSDWAInst(MCInst &MI) const {
232   if (STI.getFeatureBits()[AMDGPU::FeatureGFX9]) {
233     if (AMDGPU::getNamedOperandIdx(MI.getOpcode(), AMDGPU::OpName::sdst) != -1)
234       // VOPC - insert clamp
235       insertNamedMCOperand(MI, MCOperand::createImm(0), AMDGPU::OpName::clamp);
236   } else if (STI.getFeatureBits()[AMDGPU::FeatureVolcanicIslands]) {
237     int SDst = AMDGPU::getNamedOperandIdx(MI.getOpcode(), AMDGPU::OpName::sdst);
238     if (SDst != -1) {
239       // VOPC - insert VCC register as sdst
240       insertNamedMCOperand(MI, MCOperand::createReg(AMDGPU::VCC),
241                            AMDGPU::OpName::sdst);
242     } else {
243       // VOP1/2 - insert omod if present in instruction
244       insertNamedMCOperand(MI, MCOperand::createImm(0), AMDGPU::OpName::omod);
245     }
246   }
247   return MCDisassembler::Success;
248 }
249 
250 const char* AMDGPUDisassembler::getRegClassName(unsigned RegClassID) const {
251   return getContext().getRegisterInfo()->
252     getRegClassName(&AMDGPUMCRegisterClasses[RegClassID]);
253 }
254 
255 inline
256 MCOperand AMDGPUDisassembler::errOperand(unsigned V,
257                                          const Twine& ErrMsg) const {
258   *CommentStream << "Error: " + ErrMsg;
259 
260   // ToDo: add support for error operands to MCInst.h
261   // return MCOperand::createError(V);
262   return MCOperand();
263 }
264 
265 inline
266 MCOperand AMDGPUDisassembler::createRegOperand(unsigned int RegId) const {
267   return MCOperand::createReg(RegId);
268 }
269 
270 inline
271 MCOperand AMDGPUDisassembler::createRegOperand(unsigned RegClassID,
272                                                unsigned Val) const {
273   const auto& RegCl = AMDGPUMCRegisterClasses[RegClassID];
274   if (Val >= RegCl.getNumRegs())
275     return errOperand(Val, Twine(getRegClassName(RegClassID)) +
276                            ": unknown register " + Twine(Val));
277   return createRegOperand(RegCl.getRegister(Val));
278 }
279 
280 inline
281 MCOperand AMDGPUDisassembler::createSRegOperand(unsigned SRegClassID,
282                                                 unsigned Val) const {
283   // ToDo: SI/CI have 104 SGPRs, VI - 102
284   // Valery: here we accepting as much as we can, let assembler sort it out
285   int shift = 0;
286   switch (SRegClassID) {
287   case AMDGPU::SGPR_32RegClassID:
288   case AMDGPU::TTMP_32RegClassID:
289     break;
290   case AMDGPU::SGPR_64RegClassID:
291   case AMDGPU::TTMP_64RegClassID:
292     shift = 1;
293     break;
294   case AMDGPU::SGPR_128RegClassID:
295   case AMDGPU::TTMP_128RegClassID:
296   // ToDo: unclear if s[100:104] is available on VI. Can we use VCC as SGPR in
297   // this bundle?
298   case AMDGPU::SReg_256RegClassID:
299   // ToDo: unclear if s[96:104] is available on VI. Can we use VCC as SGPR in
300   // this bundle?
301   case AMDGPU::SReg_512RegClassID:
302     shift = 2;
303     break;
304   // ToDo: unclear if s[88:104] is available on VI. Can we use VCC as SGPR in
305   // this bundle?
306   default:
307     llvm_unreachable("unhandled register class");
308   }
309 
310   if (Val % (1 << shift)) {
311     *CommentStream << "Warning: " << getRegClassName(SRegClassID)
312                    << ": scalar reg isn't aligned " << Val;
313   }
314 
315   return createRegOperand(SRegClassID, Val >> shift);
316 }
317 
318 MCOperand AMDGPUDisassembler::decodeOperand_VS_32(unsigned Val) const {
319   return decodeSrcOp(OPW32, Val);
320 }
321 
322 MCOperand AMDGPUDisassembler::decodeOperand_VS_64(unsigned Val) const {
323   return decodeSrcOp(OPW64, Val);
324 }
325 
326 MCOperand AMDGPUDisassembler::decodeOperand_VS_128(unsigned Val) const {
327   return decodeSrcOp(OPW128, Val);
328 }
329 
330 MCOperand AMDGPUDisassembler::decodeOperand_VSrc16(unsigned Val) const {
331   return decodeSrcOp(OPW16, Val);
332 }
333 
334 MCOperand AMDGPUDisassembler::decodeOperand_VSrcV216(unsigned Val) const {
335   return decodeSrcOp(OPWV216, Val);
336 }
337 
338 MCOperand AMDGPUDisassembler::decodeOperand_VGPR_32(unsigned Val) const {
339   // Some instructions have operand restrictions beyond what the encoding
340   // allows. Some ordinarily VSrc_32 operands are VGPR_32, so clear the extra
341   // high bit.
342   Val &= 255;
343 
344   return createRegOperand(AMDGPU::VGPR_32RegClassID, Val);
345 }
346 
347 MCOperand AMDGPUDisassembler::decodeOperand_VReg_64(unsigned Val) const {
348   return createRegOperand(AMDGPU::VReg_64RegClassID, Val);
349 }
350 
351 MCOperand AMDGPUDisassembler::decodeOperand_VReg_96(unsigned Val) const {
352   return createRegOperand(AMDGPU::VReg_96RegClassID, Val);
353 }
354 
355 MCOperand AMDGPUDisassembler::decodeOperand_VReg_128(unsigned Val) const {
356   return createRegOperand(AMDGPU::VReg_128RegClassID, Val);
357 }
358 
359 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32(unsigned Val) const {
360   // table-gen generated disassembler doesn't care about operand types
361   // leaving only registry class so SSrc_32 operand turns into SReg_32
362   // and therefore we accept immediates and literals here as well
363   return decodeSrcOp(OPW32, Val);
364 }
365 
366 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32_XM0_XEXEC(
367   unsigned Val) const {
368   // SReg_32_XM0 is SReg_32 without M0 or EXEC_LO/EXEC_HI
369   return decodeOperand_SReg_32(Val);
370 }
371 
372 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32_XEXEC_HI(
373   unsigned Val) const {
374   // SReg_32_XM0 is SReg_32 without EXEC_HI
375   return decodeOperand_SReg_32(Val);
376 }
377 
378 MCOperand AMDGPUDisassembler::decodeOperand_SReg_64(unsigned Val) const {
379   return decodeSrcOp(OPW64, Val);
380 }
381 
382 MCOperand AMDGPUDisassembler::decodeOperand_SReg_64_XEXEC(unsigned Val) const {
383   return decodeSrcOp(OPW64, Val);
384 }
385 
386 MCOperand AMDGPUDisassembler::decodeOperand_SReg_128(unsigned Val) const {
387   return decodeSrcOp(OPW128, Val);
388 }
389 
390 MCOperand AMDGPUDisassembler::decodeOperand_SReg_256(unsigned Val) const {
391   return createSRegOperand(AMDGPU::SReg_256RegClassID, Val);
392 }
393 
394 MCOperand AMDGPUDisassembler::decodeOperand_SReg_512(unsigned Val) const {
395   return createSRegOperand(AMDGPU::SReg_512RegClassID, Val);
396 }
397 
398 
399 MCOperand AMDGPUDisassembler::decodeLiteralConstant() const {
400   // For now all literal constants are supposed to be unsigned integer
401   // ToDo: deal with signed/unsigned 64-bit integer constants
402   // ToDo: deal with float/double constants
403   if (!HasLiteral) {
404     if (Bytes.size() < 4) {
405       return errOperand(0, "cannot read literal, inst bytes left " +
406                         Twine(Bytes.size()));
407     }
408     HasLiteral = true;
409     Literal = eatBytes<uint32_t>(Bytes);
410   }
411   return MCOperand::createImm(Literal);
412 }
413 
414 MCOperand AMDGPUDisassembler::decodeIntImmed(unsigned Imm) {
415   using namespace AMDGPU::EncValues;
416   assert(Imm >= INLINE_INTEGER_C_MIN && Imm <= INLINE_INTEGER_C_MAX);
417   return MCOperand::createImm((Imm <= INLINE_INTEGER_C_POSITIVE_MAX) ?
418     (static_cast<int64_t>(Imm) - INLINE_INTEGER_C_MIN) :
419     (INLINE_INTEGER_C_POSITIVE_MAX - static_cast<int64_t>(Imm)));
420       // Cast prevents negative overflow.
421 }
422 
423 static int64_t getInlineImmVal32(unsigned Imm) {
424   switch (Imm) {
425   case 240:
426     return FloatToBits(0.5f);
427   case 241:
428     return FloatToBits(-0.5f);
429   case 242:
430     return FloatToBits(1.0f);
431   case 243:
432     return FloatToBits(-1.0f);
433   case 244:
434     return FloatToBits(2.0f);
435   case 245:
436     return FloatToBits(-2.0f);
437   case 246:
438     return FloatToBits(4.0f);
439   case 247:
440     return FloatToBits(-4.0f);
441   case 248: // 1 / (2 * PI)
442     return 0x3e22f983;
443   default:
444     llvm_unreachable("invalid fp inline imm");
445   }
446 }
447 
448 static int64_t getInlineImmVal64(unsigned Imm) {
449   switch (Imm) {
450   case 240:
451     return DoubleToBits(0.5);
452   case 241:
453     return DoubleToBits(-0.5);
454   case 242:
455     return DoubleToBits(1.0);
456   case 243:
457     return DoubleToBits(-1.0);
458   case 244:
459     return DoubleToBits(2.0);
460   case 245:
461     return DoubleToBits(-2.0);
462   case 246:
463     return DoubleToBits(4.0);
464   case 247:
465     return DoubleToBits(-4.0);
466   case 248: // 1 / (2 * PI)
467     return 0x3fc45f306dc9c882;
468   default:
469     llvm_unreachable("invalid fp inline imm");
470   }
471 }
472 
473 static int64_t getInlineImmVal16(unsigned Imm) {
474   switch (Imm) {
475   case 240:
476     return 0x3800;
477   case 241:
478     return 0xB800;
479   case 242:
480     return 0x3C00;
481   case 243:
482     return 0xBC00;
483   case 244:
484     return 0x4000;
485   case 245:
486     return 0xC000;
487   case 246:
488     return 0x4400;
489   case 247:
490     return 0xC400;
491   case 248: // 1 / (2 * PI)
492     return 0x3118;
493   default:
494     llvm_unreachable("invalid fp inline imm");
495   }
496 }
497 
498 MCOperand AMDGPUDisassembler::decodeFPImmed(OpWidthTy Width, unsigned Imm) {
499   assert(Imm >= AMDGPU::EncValues::INLINE_FLOATING_C_MIN
500       && Imm <= AMDGPU::EncValues::INLINE_FLOATING_C_MAX);
501 
502   // ToDo: case 248: 1/(2*PI) - is allowed only on VI
503   switch (Width) {
504   case OPW32:
505     return MCOperand::createImm(getInlineImmVal32(Imm));
506   case OPW64:
507     return MCOperand::createImm(getInlineImmVal64(Imm));
508   case OPW16:
509   case OPWV216:
510     return MCOperand::createImm(getInlineImmVal16(Imm));
511   default:
512     llvm_unreachable("implement me");
513   }
514 }
515 
516 unsigned AMDGPUDisassembler::getVgprClassId(const OpWidthTy Width) const {
517   using namespace AMDGPU;
518   assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
519   switch (Width) {
520   default: // fall
521   case OPW32:
522   case OPW16:
523   case OPWV216:
524     return VGPR_32RegClassID;
525   case OPW64: return VReg_64RegClassID;
526   case OPW128: return VReg_128RegClassID;
527   }
528 }
529 
530 unsigned AMDGPUDisassembler::getSgprClassId(const OpWidthTy Width) const {
531   using namespace AMDGPU;
532   assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
533   switch (Width) {
534   default: // fall
535   case OPW32:
536   case OPW16:
537   case OPWV216:
538     return SGPR_32RegClassID;
539   case OPW64: return SGPR_64RegClassID;
540   case OPW128: return SGPR_128RegClassID;
541   }
542 }
543 
544 unsigned AMDGPUDisassembler::getTtmpClassId(const OpWidthTy Width) const {
545   using namespace AMDGPU;
546   assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
547   switch (Width) {
548   default: // fall
549   case OPW32:
550   case OPW16:
551   case OPWV216:
552     return TTMP_32RegClassID;
553   case OPW64: return TTMP_64RegClassID;
554   case OPW128: return TTMP_128RegClassID;
555   }
556 }
557 
558 MCOperand AMDGPUDisassembler::decodeSrcOp(const OpWidthTy Width, unsigned Val) const {
559   using namespace AMDGPU::EncValues;
560   assert(Val < 512); // enum9
561 
562   if (VGPR_MIN <= Val && Val <= VGPR_MAX) {
563     return createRegOperand(getVgprClassId(Width), Val - VGPR_MIN);
564   }
565   if (Val <= SGPR_MAX) {
566     assert(SGPR_MIN == 0); // "SGPR_MIN <= Val" is always true and causes compilation warning.
567     return createSRegOperand(getSgprClassId(Width), Val - SGPR_MIN);
568   }
569   if (TTMP_MIN <= Val && Val <= TTMP_MAX) {
570     return createSRegOperand(getTtmpClassId(Width), Val - TTMP_MIN);
571   }
572 
573   if (INLINE_INTEGER_C_MIN <= Val && Val <= INLINE_INTEGER_C_MAX)
574     return decodeIntImmed(Val);
575 
576   if (INLINE_FLOATING_C_MIN <= Val && Val <= INLINE_FLOATING_C_MAX)
577     return decodeFPImmed(Width, Val);
578 
579   if (Val == LITERAL_CONST)
580     return decodeLiteralConstant();
581 
582   switch (Width) {
583   case OPW32:
584   case OPW16:
585   case OPWV216:
586     return decodeSpecialReg32(Val);
587   case OPW64:
588     return decodeSpecialReg64(Val);
589   default:
590     llvm_unreachable("unexpected immediate type");
591   }
592 }
593 
594 MCOperand AMDGPUDisassembler::decodeSpecialReg32(unsigned Val) const {
595   using namespace AMDGPU;
596   switch (Val) {
597   case 102: return createRegOperand(getMCReg(FLAT_SCR_LO, STI));
598   case 103: return createRegOperand(getMCReg(FLAT_SCR_HI, STI));
599     // ToDo: no support for xnack_mask_lo/_hi register
600   case 104:
601   case 105: break;
602   case 106: return createRegOperand(VCC_LO);
603   case 107: return createRegOperand(VCC_HI);
604   case 108: return createRegOperand(TBA_LO);
605   case 109: return createRegOperand(TBA_HI);
606   case 110: return createRegOperand(TMA_LO);
607   case 111: return createRegOperand(TMA_HI);
608   case 124: return createRegOperand(M0);
609   case 126: return createRegOperand(EXEC_LO);
610   case 127: return createRegOperand(EXEC_HI);
611   case 235: return createRegOperand(SRC_SHARED_BASE);
612   case 236: return createRegOperand(SRC_SHARED_LIMIT);
613   case 237: return createRegOperand(SRC_PRIVATE_BASE);
614   case 238: return createRegOperand(SRC_PRIVATE_LIMIT);
615     // TODO: SRC_POPS_EXITING_WAVE_ID
616     // ToDo: no support for vccz register
617   case 251: break;
618     // ToDo: no support for execz register
619   case 252: break;
620   case 253: return createRegOperand(SCC);
621   default: break;
622   }
623   return errOperand(Val, "unknown operand encoding " + Twine(Val));
624 }
625 
626 MCOperand AMDGPUDisassembler::decodeSpecialReg64(unsigned Val) const {
627   using namespace AMDGPU;
628   switch (Val) {
629   case 102: return createRegOperand(getMCReg(FLAT_SCR, STI));
630   case 106: return createRegOperand(VCC);
631   case 108: return createRegOperand(TBA);
632   case 110: return createRegOperand(TMA);
633   case 126: return createRegOperand(EXEC);
634   default: break;
635   }
636   return errOperand(Val, "unknown operand encoding " + Twine(Val));
637 }
638 
639 MCOperand AMDGPUDisassembler::decodeSDWASrc(const OpWidthTy Width,
640                                             unsigned Val) const {
641   using namespace AMDGPU::SDWA;
642 
643   if (STI.getFeatureBits()[AMDGPU::FeatureGFX9]) {
644     // XXX: static_cast<int> is needed to avoid stupid warning:
645     // compare with unsigned is always true
646     if (SDWA9EncValues::SRC_VGPR_MIN <= static_cast<int>(Val) &&
647         Val <= SDWA9EncValues::SRC_VGPR_MAX) {
648       return createRegOperand(getVgprClassId(Width),
649                               Val - SDWA9EncValues::SRC_VGPR_MIN);
650     }
651     if (SDWA9EncValues::SRC_SGPR_MIN <= Val &&
652         Val <= SDWA9EncValues::SRC_SGPR_MAX) {
653       return createSRegOperand(getSgprClassId(Width),
654                                Val - SDWA9EncValues::SRC_SGPR_MIN);
655     }
656 
657     return decodeSpecialReg32(Val - SDWA9EncValues::SRC_SGPR_MIN);
658   } else if (STI.getFeatureBits()[AMDGPU::FeatureVolcanicIslands]) {
659     return createRegOperand(getVgprClassId(Width), Val);
660   }
661   llvm_unreachable("unsupported target");
662 }
663 
664 MCOperand AMDGPUDisassembler::decodeSDWASrc16(unsigned Val) const {
665   return decodeSDWASrc(OPW16, Val);
666 }
667 
668 MCOperand AMDGPUDisassembler::decodeSDWASrc32(unsigned Val) const {
669   return decodeSDWASrc(OPW32, Val);
670 }
671 
672 
673 MCOperand AMDGPUDisassembler::decodeSDWAVopcDst(unsigned Val) const {
674   using namespace AMDGPU::SDWA;
675 
676   assert(STI.getFeatureBits()[AMDGPU::FeatureGFX9] &&
677          "SDWAVopcDst should be present only on GFX9");
678   if (Val & SDWA9EncValues::VOPC_DST_VCC_MASK) {
679     Val &= SDWA9EncValues::VOPC_DST_SGPR_MASK;
680     if (Val > AMDGPU::EncValues::SGPR_MAX) {
681       return decodeSpecialReg64(Val);
682     } else {
683       return createSRegOperand(getSgprClassId(OPW64), Val);
684     }
685   } else {
686     return createRegOperand(AMDGPU::VCC);
687   }
688 }
689 
690 //===----------------------------------------------------------------------===//
691 // AMDGPUSymbolizer
692 //===----------------------------------------------------------------------===//
693 
694 // Try to find symbol name for specified label
695 bool AMDGPUSymbolizer::tryAddingSymbolicOperand(MCInst &Inst,
696                                 raw_ostream &/*cStream*/, int64_t Value,
697                                 uint64_t /*Address*/, bool IsBranch,
698                                 uint64_t /*Offset*/, uint64_t /*InstSize*/) {
699   typedef std::tuple<uint64_t, StringRef, uint8_t> SymbolInfoTy;
700   typedef std::vector<SymbolInfoTy> SectionSymbolsTy;
701 
702   if (!IsBranch) {
703     return false;
704   }
705 
706   auto *Symbols = static_cast<SectionSymbolsTy *>(DisInfo);
707   auto Result = std::find_if(Symbols->begin(), Symbols->end(),
708                              [Value](const SymbolInfoTy& Val) {
709                                 return std::get<0>(Val) == static_cast<uint64_t>(Value)
710                                     && std::get<2>(Val) == ELF::STT_NOTYPE;
711                              });
712   if (Result != Symbols->end()) {
713     auto *Sym = Ctx.getOrCreateSymbol(std::get<1>(*Result));
714     const auto *Add = MCSymbolRefExpr::create(Sym, Ctx);
715     Inst.addOperand(MCOperand::createExpr(Add));
716     return true;
717   }
718   return false;
719 }
720 
721 void AMDGPUSymbolizer::tryAddingPcLoadReferenceComment(raw_ostream &cStream,
722                                                        int64_t Value,
723                                                        uint64_t Address) {
724   llvm_unreachable("unimplemented");
725 }
726 
727 //===----------------------------------------------------------------------===//
728 // Initialization
729 //===----------------------------------------------------------------------===//
730 
731 static MCSymbolizer *createAMDGPUSymbolizer(const Triple &/*TT*/,
732                               LLVMOpInfoCallback /*GetOpInfo*/,
733                               LLVMSymbolLookupCallback /*SymbolLookUp*/,
734                               void *DisInfo,
735                               MCContext *Ctx,
736                               std::unique_ptr<MCRelocationInfo> &&RelInfo) {
737   return new AMDGPUSymbolizer(*Ctx, std::move(RelInfo), DisInfo);
738 }
739 
740 static MCDisassembler *createAMDGPUDisassembler(const Target &T,
741                                                 const MCSubtargetInfo &STI,
742                                                 MCContext &Ctx) {
743   return new AMDGPUDisassembler(STI, Ctx);
744 }
745 
746 extern "C" void LLVMInitializeAMDGPUDisassembler() {
747   TargetRegistry::RegisterMCDisassembler(getTheGCNTarget(),
748                                          createAMDGPUDisassembler);
749   TargetRegistry::RegisterMCSymbolizer(getTheGCNTarget(),
750                                        createAMDGPUSymbolizer);
751 }
752