xref: /llvm-project/llvm/lib/Target/AMDGPU/Disassembler/AMDGPUDisassembler.cpp (revision a0342dc9eb9fe66e6287bdc3c0c0fa00deae652a)
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 "Disassembler/AMDGPUDisassembler.h"
21 #include "AMDGPU.h"
22 #include "AMDGPURegisterInfo.h"
23 #include "SIDefines.h"
24 #include "Utils/AMDGPUBaseInfo.h"
25 #include "llvm-c/Disassembler.h"
26 #include "llvm/ADT/APInt.h"
27 #include "llvm/ADT/ArrayRef.h"
28 #include "llvm/ADT/Twine.h"
29 #include "llvm/BinaryFormat/ELF.h"
30 #include "llvm/MC/MCContext.h"
31 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
32 #include "llvm/MC/MCExpr.h"
33 #include "llvm/MC/MCFixedLenDisassembler.h"
34 #include "llvm/MC/MCInst.h"
35 #include "llvm/MC/MCSubtargetInfo.h"
36 #include "llvm/Support/Endian.h"
37 #include "llvm/Support/ErrorHandling.h"
38 #include "llvm/Support/MathExtras.h"
39 #include "llvm/Support/TargetRegistry.h"
40 #include "llvm/Support/raw_ostream.h"
41 #include <algorithm>
42 #include <cassert>
43 #include <cstddef>
44 #include <cstdint>
45 #include <iterator>
46 #include <tuple>
47 #include <vector>
48 
49 using namespace llvm;
50 
51 #define DEBUG_TYPE "amdgpu-disassembler"
52 
53 using DecodeStatus = llvm::MCDisassembler::DecodeStatus;
54 
55 inline static MCDisassembler::DecodeStatus
56 addOperand(MCInst &Inst, const MCOperand& Opnd) {
57   Inst.addOperand(Opnd);
58   return Opnd.isValid() ?
59     MCDisassembler::Success :
60     MCDisassembler::SoftFail;
61 }
62 
63 static int insertNamedMCOperand(MCInst &MI, const MCOperand &Op,
64                                 uint16_t NameIdx) {
65   int OpIdx = AMDGPU::getNamedOperandIdx(MI.getOpcode(), NameIdx);
66   if (OpIdx != -1) {
67     auto I = MI.begin();
68     std::advance(I, OpIdx);
69     MI.insert(I, Op);
70   }
71   return OpIdx;
72 }
73 
74 static DecodeStatus decodeSoppBrTarget(MCInst &Inst, unsigned Imm,
75                                        uint64_t Addr, const void *Decoder) {
76   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder);
77 
78   APInt SignedOffset(18, Imm * 4, true);
79   int64_t Offset = (SignedOffset.sext(64) + 4 + Addr).getSExtValue();
80 
81   if (DAsm->tryAddingSymbolicOperand(Inst, Offset, Addr, true, 2, 2))
82     return MCDisassembler::Success;
83   return addOperand(Inst, MCOperand::createImm(Imm));
84 }
85 
86 #define DECODE_OPERAND(StaticDecoderName, DecoderName) \
87 static DecodeStatus StaticDecoderName(MCInst &Inst, \
88                                        unsigned Imm, \
89                                        uint64_t /*Addr*/, \
90                                        const void *Decoder) { \
91   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder); \
92   return addOperand(Inst, DAsm->DecoderName(Imm)); \
93 }
94 
95 #define DECODE_OPERAND_REG(RegClass) \
96 DECODE_OPERAND(Decode##RegClass##RegisterClass, decodeOperand_##RegClass)
97 
98 DECODE_OPERAND_REG(VGPR_32)
99 DECODE_OPERAND_REG(VS_32)
100 DECODE_OPERAND_REG(VS_64)
101 DECODE_OPERAND_REG(VS_128)
102 
103 DECODE_OPERAND_REG(VReg_64)
104 DECODE_OPERAND_REG(VReg_96)
105 DECODE_OPERAND_REG(VReg_128)
106 
107 DECODE_OPERAND_REG(SReg_32)
108 DECODE_OPERAND_REG(SReg_32_XM0_XEXEC)
109 DECODE_OPERAND_REG(SReg_32_XEXEC_HI)
110 DECODE_OPERAND_REG(SReg_64)
111 DECODE_OPERAND_REG(SReg_64_XEXEC)
112 DECODE_OPERAND_REG(SReg_128)
113 DECODE_OPERAND_REG(SReg_256)
114 DECODE_OPERAND_REG(SReg_512)
115 
116 static DecodeStatus decodeOperand_VSrc16(MCInst &Inst,
117                                          unsigned Imm,
118                                          uint64_t Addr,
119                                          const void *Decoder) {
120   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder);
121   return addOperand(Inst, DAsm->decodeOperand_VSrc16(Imm));
122 }
123 
124 static DecodeStatus decodeOperand_VSrcV216(MCInst &Inst,
125                                          unsigned Imm,
126                                          uint64_t Addr,
127                                          const void *Decoder) {
128   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder);
129   return addOperand(Inst, DAsm->decodeOperand_VSrcV216(Imm));
130 }
131 
132 #define DECODE_SDWA(DecName) \
133 DECODE_OPERAND(decodeSDWA##DecName, decodeSDWA##DecName)
134 
135 DECODE_SDWA(Src32)
136 DECODE_SDWA(Src16)
137 DECODE_SDWA(VopcDst)
138 
139 #include "AMDGPUGenDisassemblerTables.inc"
140 
141 //===----------------------------------------------------------------------===//
142 //
143 //===----------------------------------------------------------------------===//
144 
145 template <typename T> static inline T eatBytes(ArrayRef<uint8_t>& Bytes) {
146   assert(Bytes.size() >= sizeof(T));
147   const auto Res = support::endian::read<T, support::endianness::little>(Bytes.data());
148   Bytes = Bytes.slice(sizeof(T));
149   return Res;
150 }
151 
152 DecodeStatus AMDGPUDisassembler::tryDecodeInst(const uint8_t* Table,
153                                                MCInst &MI,
154                                                uint64_t Inst,
155                                                uint64_t Address) const {
156   assert(MI.getOpcode() == 0);
157   assert(MI.getNumOperands() == 0);
158   MCInst TmpInst;
159   HasLiteral = false;
160   const auto SavedBytes = Bytes;
161   if (decodeInstruction(Table, TmpInst, Inst, Address, this, STI)) {
162     MI = TmpInst;
163     return MCDisassembler::Success;
164   }
165   Bytes = SavedBytes;
166   return MCDisassembler::Fail;
167 }
168 
169 DecodeStatus AMDGPUDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
170                                                 ArrayRef<uint8_t> Bytes_,
171                                                 uint64_t Address,
172                                                 raw_ostream &WS,
173                                                 raw_ostream &CS) const {
174   CommentStream = &CS;
175   bool IsSDWA = false;
176 
177   // ToDo: AMDGPUDisassembler supports only VI ISA.
178   if (!STI.getFeatureBits()[AMDGPU::FeatureGCN3Encoding])
179     report_fatal_error("Disassembly not yet supported for subtarget");
180 
181   const unsigned MaxInstBytesNum = (std::min)((size_t)8, Bytes_.size());
182   Bytes = Bytes_.slice(0, MaxInstBytesNum);
183 
184   DecodeStatus Res = MCDisassembler::Fail;
185   do {
186     // ToDo: better to switch encoding length using some bit predicate
187     // but it is unknown yet, so try all we can
188 
189     // Try to decode DPP and SDWA first to solve conflict with VOP1 and VOP2
190     // encodings
191     if (Bytes.size() >= 8) {
192       const uint64_t QW = eatBytes<uint64_t>(Bytes);
193       Res = tryDecodeInst(DecoderTableDPP64, MI, QW, Address);
194       if (Res) break;
195 
196       Res = tryDecodeInst(DecoderTableSDWA64, MI, QW, Address);
197       if (Res) { IsSDWA = true;  break; }
198 
199       Res = tryDecodeInst(DecoderTableSDWA964, MI, QW, Address);
200       if (Res) { IsSDWA = true;  break; }
201     }
202 
203     // Reinitialize Bytes as DPP64 could have eaten too much
204     Bytes = Bytes_.slice(0, MaxInstBytesNum);
205 
206     // Try decode 32-bit instruction
207     if (Bytes.size() < 4) break;
208     const uint32_t DW = eatBytes<uint32_t>(Bytes);
209     Res = tryDecodeInst(DecoderTableVI32, MI, DW, Address);
210     if (Res) break;
211 
212     Res = tryDecodeInst(DecoderTableAMDGPU32, MI, DW, Address);
213     if (Res) break;
214 
215     Res = tryDecodeInst(DecoderTableGFX932, MI, DW, Address);
216     if (Res) break;
217 
218     if (Bytes.size() < 4) break;
219     const uint64_t QW = ((uint64_t)eatBytes<uint32_t>(Bytes) << 32) | DW;
220     Res = tryDecodeInst(DecoderTableVI64, MI, QW, Address);
221     if (Res) break;
222 
223     Res = tryDecodeInst(DecoderTableAMDGPU64, MI, QW, Address);
224     if (Res) break;
225 
226     Res = tryDecodeInst(DecoderTableGFX964, MI, QW, Address);
227   } while (false);
228 
229   if (Res && (MI.getOpcode() == AMDGPU::V_MAC_F32_e64_vi ||
230               MI.getOpcode() == AMDGPU::V_MAC_F32_e64_si ||
231               MI.getOpcode() == AMDGPU::V_MAC_F16_e64_vi)) {
232     // Insert dummy unused src2_modifiers.
233     insertNamedMCOperand(MI, MCOperand::createImm(0),
234                          AMDGPU::OpName::src2_modifiers);
235   }
236 
237   if (Res && IsSDWA)
238     Res = convertSDWAInst(MI);
239 
240   Size = Res ? (MaxInstBytesNum - Bytes.size()) : 0;
241   return Res;
242 }
243 
244 DecodeStatus AMDGPUDisassembler::convertSDWAInst(MCInst &MI) const {
245   if (STI.getFeatureBits()[AMDGPU::FeatureGFX9]) {
246     if (AMDGPU::getNamedOperandIdx(MI.getOpcode(), AMDGPU::OpName::sdst) != -1)
247       // VOPC - insert clamp
248       insertNamedMCOperand(MI, MCOperand::createImm(0), AMDGPU::OpName::clamp);
249   } else if (STI.getFeatureBits()[AMDGPU::FeatureVolcanicIslands]) {
250     int SDst = AMDGPU::getNamedOperandIdx(MI.getOpcode(), AMDGPU::OpName::sdst);
251     if (SDst != -1) {
252       // VOPC - insert VCC register as sdst
253       insertNamedMCOperand(MI, MCOperand::createReg(AMDGPU::VCC),
254                            AMDGPU::OpName::sdst);
255     } else {
256       // VOP1/2 - insert omod if present in instruction
257       insertNamedMCOperand(MI, MCOperand::createImm(0), AMDGPU::OpName::omod);
258     }
259   }
260   return MCDisassembler::Success;
261 }
262 
263 const char* AMDGPUDisassembler::getRegClassName(unsigned RegClassID) const {
264   return getContext().getRegisterInfo()->
265     getRegClassName(&AMDGPUMCRegisterClasses[RegClassID]);
266 }
267 
268 inline
269 MCOperand AMDGPUDisassembler::errOperand(unsigned V,
270                                          const Twine& ErrMsg) const {
271   *CommentStream << "Error: " + ErrMsg;
272 
273   // ToDo: add support for error operands to MCInst.h
274   // return MCOperand::createError(V);
275   return MCOperand();
276 }
277 
278 inline
279 MCOperand AMDGPUDisassembler::createRegOperand(unsigned int RegId) const {
280   return MCOperand::createReg(RegId);
281 }
282 
283 inline
284 MCOperand AMDGPUDisassembler::createRegOperand(unsigned RegClassID,
285                                                unsigned Val) const {
286   const auto& RegCl = AMDGPUMCRegisterClasses[RegClassID];
287   if (Val >= RegCl.getNumRegs())
288     return errOperand(Val, Twine(getRegClassName(RegClassID)) +
289                            ": unknown register " + Twine(Val));
290   return createRegOperand(RegCl.getRegister(Val));
291 }
292 
293 inline
294 MCOperand AMDGPUDisassembler::createSRegOperand(unsigned SRegClassID,
295                                                 unsigned Val) const {
296   // ToDo: SI/CI have 104 SGPRs, VI - 102
297   // Valery: here we accepting as much as we can, let assembler sort it out
298   int shift = 0;
299   switch (SRegClassID) {
300   case AMDGPU::SGPR_32RegClassID:
301   case AMDGPU::TTMP_32RegClassID:
302     break;
303   case AMDGPU::SGPR_64RegClassID:
304   case AMDGPU::TTMP_64RegClassID:
305     shift = 1;
306     break;
307   case AMDGPU::SGPR_128RegClassID:
308   case AMDGPU::TTMP_128RegClassID:
309   // ToDo: unclear if s[100:104] is available on VI. Can we use VCC as SGPR in
310   // this bundle?
311   case AMDGPU::SReg_256RegClassID:
312   // ToDo: unclear if s[96:104] is available on VI. Can we use VCC as SGPR in
313   // this bundle?
314   case AMDGPU::SReg_512RegClassID:
315     shift = 2;
316     break;
317   // ToDo: unclear if s[88:104] is available on VI. Can we use VCC as SGPR in
318   // this bundle?
319   default:
320     llvm_unreachable("unhandled register class");
321   }
322 
323   if (Val % (1 << shift)) {
324     *CommentStream << "Warning: " << getRegClassName(SRegClassID)
325                    << ": scalar reg isn't aligned " << Val;
326   }
327 
328   return createRegOperand(SRegClassID, Val >> shift);
329 }
330 
331 MCOperand AMDGPUDisassembler::decodeOperand_VS_32(unsigned Val) const {
332   return decodeSrcOp(OPW32, Val);
333 }
334 
335 MCOperand AMDGPUDisassembler::decodeOperand_VS_64(unsigned Val) const {
336   return decodeSrcOp(OPW64, Val);
337 }
338 
339 MCOperand AMDGPUDisassembler::decodeOperand_VS_128(unsigned Val) const {
340   return decodeSrcOp(OPW128, Val);
341 }
342 
343 MCOperand AMDGPUDisassembler::decodeOperand_VSrc16(unsigned Val) const {
344   return decodeSrcOp(OPW16, Val);
345 }
346 
347 MCOperand AMDGPUDisassembler::decodeOperand_VSrcV216(unsigned Val) const {
348   return decodeSrcOp(OPWV216, Val);
349 }
350 
351 MCOperand AMDGPUDisassembler::decodeOperand_VGPR_32(unsigned Val) const {
352   // Some instructions have operand restrictions beyond what the encoding
353   // allows. Some ordinarily VSrc_32 operands are VGPR_32, so clear the extra
354   // high bit.
355   Val &= 255;
356 
357   return createRegOperand(AMDGPU::VGPR_32RegClassID, Val);
358 }
359 
360 MCOperand AMDGPUDisassembler::decodeOperand_VReg_64(unsigned Val) const {
361   return createRegOperand(AMDGPU::VReg_64RegClassID, Val);
362 }
363 
364 MCOperand AMDGPUDisassembler::decodeOperand_VReg_96(unsigned Val) const {
365   return createRegOperand(AMDGPU::VReg_96RegClassID, Val);
366 }
367 
368 MCOperand AMDGPUDisassembler::decodeOperand_VReg_128(unsigned Val) const {
369   return createRegOperand(AMDGPU::VReg_128RegClassID, Val);
370 }
371 
372 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32(unsigned Val) const {
373   // table-gen generated disassembler doesn't care about operand types
374   // leaving only registry class so SSrc_32 operand turns into SReg_32
375   // and therefore we accept immediates and literals here as well
376   return decodeSrcOp(OPW32, Val);
377 }
378 
379 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32_XM0_XEXEC(
380   unsigned Val) const {
381   // SReg_32_XM0 is SReg_32 without M0 or EXEC_LO/EXEC_HI
382   return decodeOperand_SReg_32(Val);
383 }
384 
385 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32_XEXEC_HI(
386   unsigned Val) const {
387   // SReg_32_XM0 is SReg_32 without EXEC_HI
388   return decodeOperand_SReg_32(Val);
389 }
390 
391 MCOperand AMDGPUDisassembler::decodeOperand_SReg_64(unsigned Val) const {
392   return decodeSrcOp(OPW64, Val);
393 }
394 
395 MCOperand AMDGPUDisassembler::decodeOperand_SReg_64_XEXEC(unsigned Val) const {
396   return decodeSrcOp(OPW64, Val);
397 }
398 
399 MCOperand AMDGPUDisassembler::decodeOperand_SReg_128(unsigned Val) const {
400   return decodeSrcOp(OPW128, Val);
401 }
402 
403 MCOperand AMDGPUDisassembler::decodeOperand_SReg_256(unsigned Val) const {
404   return createSRegOperand(AMDGPU::SReg_256RegClassID, Val);
405 }
406 
407 MCOperand AMDGPUDisassembler::decodeOperand_SReg_512(unsigned Val) const {
408   return createSRegOperand(AMDGPU::SReg_512RegClassID, Val);
409 }
410 
411 MCOperand AMDGPUDisassembler::decodeLiteralConstant() const {
412   // For now all literal constants are supposed to be unsigned integer
413   // ToDo: deal with signed/unsigned 64-bit integer constants
414   // ToDo: deal with float/double constants
415   if (!HasLiteral) {
416     if (Bytes.size() < 4) {
417       return errOperand(0, "cannot read literal, inst bytes left " +
418                         Twine(Bytes.size()));
419     }
420     HasLiteral = true;
421     Literal = eatBytes<uint32_t>(Bytes);
422   }
423   return MCOperand::createImm(Literal);
424 }
425 
426 MCOperand AMDGPUDisassembler::decodeIntImmed(unsigned Imm) {
427   using namespace AMDGPU::EncValues;
428 
429   assert(Imm >= INLINE_INTEGER_C_MIN && Imm <= INLINE_INTEGER_C_MAX);
430   return MCOperand::createImm((Imm <= INLINE_INTEGER_C_POSITIVE_MAX) ?
431     (static_cast<int64_t>(Imm) - INLINE_INTEGER_C_MIN) :
432     (INLINE_INTEGER_C_POSITIVE_MAX - static_cast<int64_t>(Imm)));
433       // Cast prevents negative overflow.
434 }
435 
436 static int64_t getInlineImmVal32(unsigned Imm) {
437   switch (Imm) {
438   case 240:
439     return FloatToBits(0.5f);
440   case 241:
441     return FloatToBits(-0.5f);
442   case 242:
443     return FloatToBits(1.0f);
444   case 243:
445     return FloatToBits(-1.0f);
446   case 244:
447     return FloatToBits(2.0f);
448   case 245:
449     return FloatToBits(-2.0f);
450   case 246:
451     return FloatToBits(4.0f);
452   case 247:
453     return FloatToBits(-4.0f);
454   case 248: // 1 / (2 * PI)
455     return 0x3e22f983;
456   default:
457     llvm_unreachable("invalid fp inline imm");
458   }
459 }
460 
461 static int64_t getInlineImmVal64(unsigned Imm) {
462   switch (Imm) {
463   case 240:
464     return DoubleToBits(0.5);
465   case 241:
466     return DoubleToBits(-0.5);
467   case 242:
468     return DoubleToBits(1.0);
469   case 243:
470     return DoubleToBits(-1.0);
471   case 244:
472     return DoubleToBits(2.0);
473   case 245:
474     return DoubleToBits(-2.0);
475   case 246:
476     return DoubleToBits(4.0);
477   case 247:
478     return DoubleToBits(-4.0);
479   case 248: // 1 / (2 * PI)
480     return 0x3fc45f306dc9c882;
481   default:
482     llvm_unreachable("invalid fp inline imm");
483   }
484 }
485 
486 static int64_t getInlineImmVal16(unsigned Imm) {
487   switch (Imm) {
488   case 240:
489     return 0x3800;
490   case 241:
491     return 0xB800;
492   case 242:
493     return 0x3C00;
494   case 243:
495     return 0xBC00;
496   case 244:
497     return 0x4000;
498   case 245:
499     return 0xC000;
500   case 246:
501     return 0x4400;
502   case 247:
503     return 0xC400;
504   case 248: // 1 / (2 * PI)
505     return 0x3118;
506   default:
507     llvm_unreachable("invalid fp inline imm");
508   }
509 }
510 
511 MCOperand AMDGPUDisassembler::decodeFPImmed(OpWidthTy Width, unsigned Imm) {
512   assert(Imm >= AMDGPU::EncValues::INLINE_FLOATING_C_MIN
513       && Imm <= AMDGPU::EncValues::INLINE_FLOATING_C_MAX);
514 
515   // ToDo: case 248: 1/(2*PI) - is allowed only on VI
516   switch (Width) {
517   case OPW32:
518     return MCOperand::createImm(getInlineImmVal32(Imm));
519   case OPW64:
520     return MCOperand::createImm(getInlineImmVal64(Imm));
521   case OPW16:
522   case OPWV216:
523     return MCOperand::createImm(getInlineImmVal16(Imm));
524   default:
525     llvm_unreachable("implement me");
526   }
527 }
528 
529 unsigned AMDGPUDisassembler::getVgprClassId(const OpWidthTy Width) const {
530   using namespace AMDGPU;
531 
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 VGPR_32RegClassID;
539   case OPW64: return VReg_64RegClassID;
540   case OPW128: return VReg_128RegClassID;
541   }
542 }
543 
544 unsigned AMDGPUDisassembler::getSgprClassId(const OpWidthTy Width) const {
545   using namespace AMDGPU;
546 
547   assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
548   switch (Width) {
549   default: // fall
550   case OPW32:
551   case OPW16:
552   case OPWV216:
553     return SGPR_32RegClassID;
554   case OPW64: return SGPR_64RegClassID;
555   case OPW128: return SGPR_128RegClassID;
556   }
557 }
558 
559 unsigned AMDGPUDisassembler::getTtmpClassId(const OpWidthTy Width) const {
560   using namespace AMDGPU;
561 
562   assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
563   switch (Width) {
564   default: // fall
565   case OPW32:
566   case OPW16:
567   case OPWV216:
568     return TTMP_32RegClassID;
569   case OPW64: return TTMP_64RegClassID;
570   case OPW128: return TTMP_128RegClassID;
571   }
572 }
573 
574 MCOperand AMDGPUDisassembler::decodeSrcOp(const OpWidthTy Width, unsigned Val) const {
575   using namespace AMDGPU::EncValues;
576 
577   assert(Val < 512); // enum9
578 
579   if (VGPR_MIN <= Val && Val <= VGPR_MAX) {
580     return createRegOperand(getVgprClassId(Width), Val - VGPR_MIN);
581   }
582   if (Val <= SGPR_MAX) {
583     assert(SGPR_MIN == 0); // "SGPR_MIN <= Val" is always true and causes compilation warning.
584     return createSRegOperand(getSgprClassId(Width), Val - SGPR_MIN);
585   }
586   if (TTMP_MIN <= Val && Val <= TTMP_MAX) {
587     return createSRegOperand(getTtmpClassId(Width), Val - TTMP_MIN);
588   }
589 
590   if (INLINE_INTEGER_C_MIN <= Val && Val <= INLINE_INTEGER_C_MAX)
591     return decodeIntImmed(Val);
592 
593   if (INLINE_FLOATING_C_MIN <= Val && Val <= INLINE_FLOATING_C_MAX)
594     return decodeFPImmed(Width, Val);
595 
596   if (Val == LITERAL_CONST)
597     return decodeLiteralConstant();
598 
599   switch (Width) {
600   case OPW32:
601   case OPW16:
602   case OPWV216:
603     return decodeSpecialReg32(Val);
604   case OPW64:
605     return decodeSpecialReg64(Val);
606   default:
607     llvm_unreachable("unexpected immediate type");
608   }
609 }
610 
611 MCOperand AMDGPUDisassembler::decodeSpecialReg32(unsigned Val) const {
612   using namespace AMDGPU;
613 
614   switch (Val) {
615   case 102: return createRegOperand(getMCReg(FLAT_SCR_LO, STI));
616   case 103: return createRegOperand(getMCReg(FLAT_SCR_HI, STI));
617     // ToDo: no support for xnack_mask_lo/_hi register
618   case 104:
619   case 105: break;
620   case 106: return createRegOperand(VCC_LO);
621   case 107: return createRegOperand(VCC_HI);
622   case 108: return createRegOperand(TBA_LO);
623   case 109: return createRegOperand(TBA_HI);
624   case 110: return createRegOperand(TMA_LO);
625   case 111: return createRegOperand(TMA_HI);
626   case 124: return createRegOperand(M0);
627   case 126: return createRegOperand(EXEC_LO);
628   case 127: return createRegOperand(EXEC_HI);
629   case 235: return createRegOperand(SRC_SHARED_BASE);
630   case 236: return createRegOperand(SRC_SHARED_LIMIT);
631   case 237: return createRegOperand(SRC_PRIVATE_BASE);
632   case 238: return createRegOperand(SRC_PRIVATE_LIMIT);
633     // TODO: SRC_POPS_EXITING_WAVE_ID
634     // ToDo: no support for vccz register
635   case 251: break;
636     // ToDo: no support for execz register
637   case 252: break;
638   case 253: return createRegOperand(SCC);
639   default: break;
640   }
641   return errOperand(Val, "unknown operand encoding " + Twine(Val));
642 }
643 
644 MCOperand AMDGPUDisassembler::decodeSpecialReg64(unsigned Val) const {
645   using namespace AMDGPU;
646 
647   switch (Val) {
648   case 102: return createRegOperand(getMCReg(FLAT_SCR, STI));
649   case 106: return createRegOperand(VCC);
650   case 108: return createRegOperand(TBA);
651   case 110: return createRegOperand(TMA);
652   case 126: return createRegOperand(EXEC);
653   default: break;
654   }
655   return errOperand(Val, "unknown operand encoding " + Twine(Val));
656 }
657 
658 MCOperand AMDGPUDisassembler::decodeSDWASrc(const OpWidthTy Width,
659                                             unsigned Val) const {
660   using namespace AMDGPU::SDWA;
661 
662   if (STI.getFeatureBits()[AMDGPU::FeatureGFX9]) {
663     // XXX: static_cast<int> is needed to avoid stupid warning:
664     // compare with unsigned is always true
665     if (SDWA9EncValues::SRC_VGPR_MIN <= static_cast<int>(Val) &&
666         Val <= SDWA9EncValues::SRC_VGPR_MAX) {
667       return createRegOperand(getVgprClassId(Width),
668                               Val - SDWA9EncValues::SRC_VGPR_MIN);
669     }
670     if (SDWA9EncValues::SRC_SGPR_MIN <= Val &&
671         Val <= SDWA9EncValues::SRC_SGPR_MAX) {
672       return createSRegOperand(getSgprClassId(Width),
673                                Val - SDWA9EncValues::SRC_SGPR_MIN);
674     }
675 
676     return decodeSpecialReg32(Val - SDWA9EncValues::SRC_SGPR_MIN);
677   } else if (STI.getFeatureBits()[AMDGPU::FeatureVolcanicIslands]) {
678     return createRegOperand(getVgprClassId(Width), Val);
679   }
680   llvm_unreachable("unsupported target");
681 }
682 
683 MCOperand AMDGPUDisassembler::decodeSDWASrc16(unsigned Val) const {
684   return decodeSDWASrc(OPW16, Val);
685 }
686 
687 MCOperand AMDGPUDisassembler::decodeSDWASrc32(unsigned Val) const {
688   return decodeSDWASrc(OPW32, Val);
689 }
690 
691 MCOperand AMDGPUDisassembler::decodeSDWAVopcDst(unsigned Val) const {
692   using namespace AMDGPU::SDWA;
693 
694   assert(STI.getFeatureBits()[AMDGPU::FeatureGFX9] &&
695          "SDWAVopcDst should be present only on GFX9");
696   if (Val & SDWA9EncValues::VOPC_DST_VCC_MASK) {
697     Val &= SDWA9EncValues::VOPC_DST_SGPR_MASK;
698     if (Val > AMDGPU::EncValues::SGPR_MAX) {
699       return decodeSpecialReg64(Val);
700     } else {
701       return createSRegOperand(getSgprClassId(OPW64), Val);
702     }
703   } else {
704     return createRegOperand(AMDGPU::VCC);
705   }
706 }
707 
708 //===----------------------------------------------------------------------===//
709 // AMDGPUSymbolizer
710 //===----------------------------------------------------------------------===//
711 
712 // Try to find symbol name for specified label
713 bool AMDGPUSymbolizer::tryAddingSymbolicOperand(MCInst &Inst,
714                                 raw_ostream &/*cStream*/, int64_t Value,
715                                 uint64_t /*Address*/, bool IsBranch,
716                                 uint64_t /*Offset*/, uint64_t /*InstSize*/) {
717   using SymbolInfoTy = std::tuple<uint64_t, StringRef, uint8_t>;
718   using SectionSymbolsTy = std::vector<SymbolInfoTy>;
719 
720   if (!IsBranch) {
721     return false;
722   }
723 
724   auto *Symbols = static_cast<SectionSymbolsTy *>(DisInfo);
725   auto Result = std::find_if(Symbols->begin(), Symbols->end(),
726                              [Value](const SymbolInfoTy& Val) {
727                                 return std::get<0>(Val) == static_cast<uint64_t>(Value)
728                                     && std::get<2>(Val) == ELF::STT_NOTYPE;
729                              });
730   if (Result != Symbols->end()) {
731     auto *Sym = Ctx.getOrCreateSymbol(std::get<1>(*Result));
732     const auto *Add = MCSymbolRefExpr::create(Sym, Ctx);
733     Inst.addOperand(MCOperand::createExpr(Add));
734     return true;
735   }
736   return false;
737 }
738 
739 void AMDGPUSymbolizer::tryAddingPcLoadReferenceComment(raw_ostream &cStream,
740                                                        int64_t Value,
741                                                        uint64_t Address) {
742   llvm_unreachable("unimplemented");
743 }
744 
745 //===----------------------------------------------------------------------===//
746 // Initialization
747 //===----------------------------------------------------------------------===//
748 
749 static MCSymbolizer *createAMDGPUSymbolizer(const Triple &/*TT*/,
750                               LLVMOpInfoCallback /*GetOpInfo*/,
751                               LLVMSymbolLookupCallback /*SymbolLookUp*/,
752                               void *DisInfo,
753                               MCContext *Ctx,
754                               std::unique_ptr<MCRelocationInfo> &&RelInfo) {
755   return new AMDGPUSymbolizer(*Ctx, std::move(RelInfo), DisInfo);
756 }
757 
758 static MCDisassembler *createAMDGPUDisassembler(const Target &T,
759                                                 const MCSubtargetInfo &STI,
760                                                 MCContext &Ctx) {
761   return new AMDGPUDisassembler(STI, Ctx);
762 }
763 
764 extern "C" void LLVMInitializeAMDGPUDisassembler() {
765   TargetRegistry::RegisterMCDisassembler(getTheGCNTarget(),
766                                          createAMDGPUDisassembler);
767   TargetRegistry::RegisterMCSymbolizer(getTheGCNTarget(),
768                                        createAMDGPUSymbolizer);
769 }
770