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       if (STI.getFeatureBits()[AMDGPU::FeatureUnpackedD16VMem]) {
203         Res = tryDecodeInst(DecoderTableGFX80_UNPACKED64, MI, QW, Address);
204         if (Res)
205           break;
206       }
207 
208       // Some GFX9 subtargets repurposed the v_mad_mix_f32, v_mad_mixlo_f16 and
209       // v_mad_mixhi_f16 for FMA variants. Try to decode using this special
210       // table first so we print the correct name.
211       if (STI.getFeatureBits()[AMDGPU::FeatureFmaMixInsts]) {
212         Res = tryDecodeInst(DecoderTableGFX9_DL64, MI, QW, Address);
213         if (Res)
214           break;
215       }
216     }
217 
218     // Reinitialize Bytes as DPP64 could have eaten too much
219     Bytes = Bytes_.slice(0, MaxInstBytesNum);
220 
221     // Try decode 32-bit instruction
222     if (Bytes.size() < 4) break;
223     const uint32_t DW = eatBytes<uint32_t>(Bytes);
224     Res = tryDecodeInst(DecoderTableVI32, MI, DW, Address);
225     if (Res) break;
226 
227     Res = tryDecodeInst(DecoderTableAMDGPU32, MI, DW, Address);
228     if (Res) break;
229 
230     Res = tryDecodeInst(DecoderTableGFX932, MI, DW, Address);
231     if (Res) break;
232 
233     if (Bytes.size() < 4) break;
234     const uint64_t QW = ((uint64_t)eatBytes<uint32_t>(Bytes) << 32) | DW;
235     Res = tryDecodeInst(DecoderTableVI64, MI, QW, Address);
236     if (Res) break;
237 
238     Res = tryDecodeInst(DecoderTableAMDGPU64, MI, QW, Address);
239     if (Res) break;
240 
241     Res = tryDecodeInst(DecoderTableGFX964, MI, QW, Address);
242   } while (false);
243 
244   if (Res && (MI.getOpcode() == AMDGPU::V_MAC_F32_e64_vi ||
245               MI.getOpcode() == AMDGPU::V_MAC_F32_e64_si ||
246               MI.getOpcode() == AMDGPU::V_MAC_F16_e64_vi)) {
247     // Insert dummy unused src2_modifiers.
248     insertNamedMCOperand(MI, MCOperand::createImm(0),
249                          AMDGPU::OpName::src2_modifiers);
250   }
251 
252   if (Res && (MCII->get(MI.getOpcode()).TSFlags & SIInstrFlags::MIMG)) {
253     Res = convertMIMGInst(MI);
254   }
255 
256   if (Res && IsSDWA)
257     Res = convertSDWAInst(MI);
258 
259   // if the opcode was not recognized we'll assume a Size of 4 bytes
260   // (unless there are fewer bytes left)
261   Size = Res ? (MaxInstBytesNum - Bytes.size())
262              : std::min((size_t)4, Bytes_.size());
263   return Res;
264 }
265 
266 DecodeStatus AMDGPUDisassembler::convertSDWAInst(MCInst &MI) const {
267   if (STI.getFeatureBits()[AMDGPU::FeatureGFX9]) {
268     if (AMDGPU::getNamedOperandIdx(MI.getOpcode(), AMDGPU::OpName::sdst) != -1)
269       // VOPC - insert clamp
270       insertNamedMCOperand(MI, MCOperand::createImm(0), AMDGPU::OpName::clamp);
271   } else if (STI.getFeatureBits()[AMDGPU::FeatureVolcanicIslands]) {
272     int SDst = AMDGPU::getNamedOperandIdx(MI.getOpcode(), AMDGPU::OpName::sdst);
273     if (SDst != -1) {
274       // VOPC - insert VCC register as sdst
275       insertNamedMCOperand(MI, createRegOperand(AMDGPU::VCC),
276                            AMDGPU::OpName::sdst);
277     } else {
278       // VOP1/2 - insert omod if present in instruction
279       insertNamedMCOperand(MI, MCOperand::createImm(0), AMDGPU::OpName::omod);
280     }
281   }
282   return MCDisassembler::Success;
283 }
284 
285 // Note that MIMG format provides no information about VADDR size.
286 // Consequently, decoded instructions always show address
287 // as if it has 1 dword, which could be not really so.
288 DecodeStatus AMDGPUDisassembler::convertMIMGInst(MCInst &MI) const {
289 
290   if (MCII->get(MI.getOpcode()).TSFlags & SIInstrFlags::Gather4) {
291     return MCDisassembler::Success;
292   }
293 
294   int VDstIdx = AMDGPU::getNamedOperandIdx(MI.getOpcode(),
295                                            AMDGPU::OpName::vdst);
296 
297   int VDataIdx = AMDGPU::getNamedOperandIdx(MI.getOpcode(),
298                                             AMDGPU::OpName::vdata);
299 
300   int DMaskIdx = AMDGPU::getNamedOperandIdx(MI.getOpcode(),
301                                             AMDGPU::OpName::dmask);
302 
303   int TFEIdx   = AMDGPU::getNamedOperandIdx(MI.getOpcode(),
304                                             AMDGPU::OpName::tfe);
305 
306   assert(VDataIdx != -1);
307   assert(DMaskIdx != -1);
308   assert(TFEIdx != -1);
309 
310   bool IsAtomic = (VDstIdx != -1);
311 
312   unsigned DMask = MI.getOperand(DMaskIdx).getImm() & 0xf;
313   if (DMask == 0)
314     return MCDisassembler::Success;
315 
316   unsigned DstSize = countPopulation(DMask);
317   if (DstSize == 1)
318     return MCDisassembler::Success;
319 
320   bool D16 = MCII->get(MI.getOpcode()).TSFlags & SIInstrFlags::D16;
321   if (D16 && AMDGPU::hasPackedD16(STI)) {
322     DstSize = (DstSize + 1) / 2;
323   }
324 
325   // FIXME: Add tfe support
326   if (MI.getOperand(TFEIdx).getImm())
327     return MCDisassembler::Success;
328 
329   int NewOpcode = -1;
330 
331   if (IsAtomic) {
332     if (DMask == 0x1 || DMask == 0x3 || DMask == 0xF) {
333       NewOpcode = AMDGPU::getMaskedMIMGAtomicOp(*MCII, MI.getOpcode(), DstSize);
334     }
335     if (NewOpcode == -1) return MCDisassembler::Success;
336   } else {
337     NewOpcode = AMDGPU::getMaskedMIMGOp(*MCII, MI.getOpcode(), DstSize);
338     assert(NewOpcode != -1 && "could not find matching mimg channel instruction");
339   }
340 
341   auto RCID = MCII->get(NewOpcode).OpInfo[VDataIdx].RegClass;
342 
343   // Get first subregister of VData
344   unsigned Vdata0 = MI.getOperand(VDataIdx).getReg();
345   unsigned VdataSub0 = MRI.getSubReg(Vdata0, AMDGPU::sub0);
346   Vdata0 = (VdataSub0 != 0)? VdataSub0 : Vdata0;
347 
348   // Widen the register to the correct number of enabled channels.
349   auto NewVdata = MRI.getMatchingSuperReg(Vdata0, AMDGPU::sub0,
350                                           &MRI.getRegClass(RCID));
351   if (NewVdata == AMDGPU::NoRegister) {
352     // It's possible to encode this such that the low register + enabled
353     // components exceeds the register count.
354     return MCDisassembler::Success;
355   }
356 
357   MI.setOpcode(NewOpcode);
358   // vaddr will be always appear as a single VGPR. This will look different than
359   // how it is usually emitted because the number of register components is not
360   // in the instruction encoding.
361   MI.getOperand(VDataIdx) = MCOperand::createReg(NewVdata);
362 
363   if (IsAtomic) {
364     // Atomic operations have an additional operand (a copy of data)
365     MI.getOperand(VDstIdx) = MCOperand::createReg(NewVdata);
366   }
367 
368   return MCDisassembler::Success;
369 }
370 
371 const char* AMDGPUDisassembler::getRegClassName(unsigned RegClassID) const {
372   return getContext().getRegisterInfo()->
373     getRegClassName(&AMDGPUMCRegisterClasses[RegClassID]);
374 }
375 
376 inline
377 MCOperand AMDGPUDisassembler::errOperand(unsigned V,
378                                          const Twine& ErrMsg) const {
379   *CommentStream << "Error: " + ErrMsg;
380 
381   // ToDo: add support for error operands to MCInst.h
382   // return MCOperand::createError(V);
383   return MCOperand();
384 }
385 
386 inline
387 MCOperand AMDGPUDisassembler::createRegOperand(unsigned int RegId) const {
388   return MCOperand::createReg(AMDGPU::getMCReg(RegId, STI));
389 }
390 
391 inline
392 MCOperand AMDGPUDisassembler::createRegOperand(unsigned RegClassID,
393                                                unsigned Val) const {
394   const auto& RegCl = AMDGPUMCRegisterClasses[RegClassID];
395   if (Val >= RegCl.getNumRegs())
396     return errOperand(Val, Twine(getRegClassName(RegClassID)) +
397                            ": unknown register " + Twine(Val));
398   return createRegOperand(RegCl.getRegister(Val));
399 }
400 
401 inline
402 MCOperand AMDGPUDisassembler::createSRegOperand(unsigned SRegClassID,
403                                                 unsigned Val) const {
404   // ToDo: SI/CI have 104 SGPRs, VI - 102
405   // Valery: here we accepting as much as we can, let assembler sort it out
406   int shift = 0;
407   switch (SRegClassID) {
408   case AMDGPU::SGPR_32RegClassID:
409   case AMDGPU::TTMP_32RegClassID:
410     break;
411   case AMDGPU::SGPR_64RegClassID:
412   case AMDGPU::TTMP_64RegClassID:
413     shift = 1;
414     break;
415   case AMDGPU::SGPR_128RegClassID:
416   case AMDGPU::TTMP_128RegClassID:
417   // ToDo: unclear if s[100:104] is available on VI. Can we use VCC as SGPR in
418   // this bundle?
419   case AMDGPU::SGPR_256RegClassID:
420   case AMDGPU::TTMP_256RegClassID:
421     // ToDo: unclear if s[96:104] is available on VI. Can we use VCC as SGPR in
422   // this bundle?
423   case AMDGPU::SGPR_512RegClassID:
424   case AMDGPU::TTMP_512RegClassID:
425     shift = 2;
426     break;
427   // ToDo: unclear if s[88:104] is available on VI. Can we use VCC as SGPR in
428   // this bundle?
429   default:
430     llvm_unreachable("unhandled register class");
431   }
432 
433   if (Val % (1 << shift)) {
434     *CommentStream << "Warning: " << getRegClassName(SRegClassID)
435                    << ": scalar reg isn't aligned " << Val;
436   }
437 
438   return createRegOperand(SRegClassID, Val >> shift);
439 }
440 
441 MCOperand AMDGPUDisassembler::decodeOperand_VS_32(unsigned Val) const {
442   return decodeSrcOp(OPW32, Val);
443 }
444 
445 MCOperand AMDGPUDisassembler::decodeOperand_VS_64(unsigned Val) const {
446   return decodeSrcOp(OPW64, Val);
447 }
448 
449 MCOperand AMDGPUDisassembler::decodeOperand_VS_128(unsigned Val) const {
450   return decodeSrcOp(OPW128, Val);
451 }
452 
453 MCOperand AMDGPUDisassembler::decodeOperand_VSrc16(unsigned Val) const {
454   return decodeSrcOp(OPW16, Val);
455 }
456 
457 MCOperand AMDGPUDisassembler::decodeOperand_VSrcV216(unsigned Val) const {
458   return decodeSrcOp(OPWV216, Val);
459 }
460 
461 MCOperand AMDGPUDisassembler::decodeOperand_VGPR_32(unsigned Val) const {
462   // Some instructions have operand restrictions beyond what the encoding
463   // allows. Some ordinarily VSrc_32 operands are VGPR_32, so clear the extra
464   // high bit.
465   Val &= 255;
466 
467   return createRegOperand(AMDGPU::VGPR_32RegClassID, Val);
468 }
469 
470 MCOperand AMDGPUDisassembler::decodeOperand_VReg_64(unsigned Val) const {
471   return createRegOperand(AMDGPU::VReg_64RegClassID, Val);
472 }
473 
474 MCOperand AMDGPUDisassembler::decodeOperand_VReg_96(unsigned Val) const {
475   return createRegOperand(AMDGPU::VReg_96RegClassID, Val);
476 }
477 
478 MCOperand AMDGPUDisassembler::decodeOperand_VReg_128(unsigned Val) const {
479   return createRegOperand(AMDGPU::VReg_128RegClassID, Val);
480 }
481 
482 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32(unsigned Val) const {
483   // table-gen generated disassembler doesn't care about operand types
484   // leaving only registry class so SSrc_32 operand turns into SReg_32
485   // and therefore we accept immediates and literals here as well
486   return decodeSrcOp(OPW32, Val);
487 }
488 
489 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32_XM0_XEXEC(
490   unsigned Val) const {
491   // SReg_32_XM0 is SReg_32 without M0 or EXEC_LO/EXEC_HI
492   return decodeOperand_SReg_32(Val);
493 }
494 
495 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32_XEXEC_HI(
496   unsigned Val) const {
497   // SReg_32_XM0 is SReg_32 without EXEC_HI
498   return decodeOperand_SReg_32(Val);
499 }
500 
501 MCOperand AMDGPUDisassembler::decodeOperand_SReg_64(unsigned Val) const {
502   return decodeSrcOp(OPW64, Val);
503 }
504 
505 MCOperand AMDGPUDisassembler::decodeOperand_SReg_64_XEXEC(unsigned Val) const {
506   return decodeSrcOp(OPW64, Val);
507 }
508 
509 MCOperand AMDGPUDisassembler::decodeOperand_SReg_128(unsigned Val) const {
510   return decodeSrcOp(OPW128, Val);
511 }
512 
513 MCOperand AMDGPUDisassembler::decodeOperand_SReg_256(unsigned Val) const {
514   return decodeDstOp(OPW256, Val);
515 }
516 
517 MCOperand AMDGPUDisassembler::decodeOperand_SReg_512(unsigned Val) const {
518   return decodeDstOp(OPW512, Val);
519 }
520 
521 MCOperand AMDGPUDisassembler::decodeLiteralConstant() const {
522   // For now all literal constants are supposed to be unsigned integer
523   // ToDo: deal with signed/unsigned 64-bit integer constants
524   // ToDo: deal with float/double constants
525   if (!HasLiteral) {
526     if (Bytes.size() < 4) {
527       return errOperand(0, "cannot read literal, inst bytes left " +
528                         Twine(Bytes.size()));
529     }
530     HasLiteral = true;
531     Literal = eatBytes<uint32_t>(Bytes);
532   }
533   return MCOperand::createImm(Literal);
534 }
535 
536 MCOperand AMDGPUDisassembler::decodeIntImmed(unsigned Imm) {
537   using namespace AMDGPU::EncValues;
538 
539   assert(Imm >= INLINE_INTEGER_C_MIN && Imm <= INLINE_INTEGER_C_MAX);
540   return MCOperand::createImm((Imm <= INLINE_INTEGER_C_POSITIVE_MAX) ?
541     (static_cast<int64_t>(Imm) - INLINE_INTEGER_C_MIN) :
542     (INLINE_INTEGER_C_POSITIVE_MAX - static_cast<int64_t>(Imm)));
543       // Cast prevents negative overflow.
544 }
545 
546 static int64_t getInlineImmVal32(unsigned Imm) {
547   switch (Imm) {
548   case 240:
549     return FloatToBits(0.5f);
550   case 241:
551     return FloatToBits(-0.5f);
552   case 242:
553     return FloatToBits(1.0f);
554   case 243:
555     return FloatToBits(-1.0f);
556   case 244:
557     return FloatToBits(2.0f);
558   case 245:
559     return FloatToBits(-2.0f);
560   case 246:
561     return FloatToBits(4.0f);
562   case 247:
563     return FloatToBits(-4.0f);
564   case 248: // 1 / (2 * PI)
565     return 0x3e22f983;
566   default:
567     llvm_unreachable("invalid fp inline imm");
568   }
569 }
570 
571 static int64_t getInlineImmVal64(unsigned Imm) {
572   switch (Imm) {
573   case 240:
574     return DoubleToBits(0.5);
575   case 241:
576     return DoubleToBits(-0.5);
577   case 242:
578     return DoubleToBits(1.0);
579   case 243:
580     return DoubleToBits(-1.0);
581   case 244:
582     return DoubleToBits(2.0);
583   case 245:
584     return DoubleToBits(-2.0);
585   case 246:
586     return DoubleToBits(4.0);
587   case 247:
588     return DoubleToBits(-4.0);
589   case 248: // 1 / (2 * PI)
590     return 0x3fc45f306dc9c882;
591   default:
592     llvm_unreachable("invalid fp inline imm");
593   }
594 }
595 
596 static int64_t getInlineImmVal16(unsigned Imm) {
597   switch (Imm) {
598   case 240:
599     return 0x3800;
600   case 241:
601     return 0xB800;
602   case 242:
603     return 0x3C00;
604   case 243:
605     return 0xBC00;
606   case 244:
607     return 0x4000;
608   case 245:
609     return 0xC000;
610   case 246:
611     return 0x4400;
612   case 247:
613     return 0xC400;
614   case 248: // 1 / (2 * PI)
615     return 0x3118;
616   default:
617     llvm_unreachable("invalid fp inline imm");
618   }
619 }
620 
621 MCOperand AMDGPUDisassembler::decodeFPImmed(OpWidthTy Width, unsigned Imm) {
622   assert(Imm >= AMDGPU::EncValues::INLINE_FLOATING_C_MIN
623       && Imm <= AMDGPU::EncValues::INLINE_FLOATING_C_MAX);
624 
625   // ToDo: case 248: 1/(2*PI) - is allowed only on VI
626   switch (Width) {
627   case OPW32:
628     return MCOperand::createImm(getInlineImmVal32(Imm));
629   case OPW64:
630     return MCOperand::createImm(getInlineImmVal64(Imm));
631   case OPW16:
632   case OPWV216:
633     return MCOperand::createImm(getInlineImmVal16(Imm));
634   default:
635     llvm_unreachable("implement me");
636   }
637 }
638 
639 unsigned AMDGPUDisassembler::getVgprClassId(const OpWidthTy Width) const {
640   using namespace AMDGPU;
641 
642   assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
643   switch (Width) {
644   default: // fall
645   case OPW32:
646   case OPW16:
647   case OPWV216:
648     return VGPR_32RegClassID;
649   case OPW64: return VReg_64RegClassID;
650   case OPW128: return VReg_128RegClassID;
651   }
652 }
653 
654 unsigned AMDGPUDisassembler::getSgprClassId(const OpWidthTy Width) const {
655   using namespace AMDGPU;
656 
657   assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
658   switch (Width) {
659   default: // fall
660   case OPW32:
661   case OPW16:
662   case OPWV216:
663     return SGPR_32RegClassID;
664   case OPW64: return SGPR_64RegClassID;
665   case OPW128: return SGPR_128RegClassID;
666   case OPW256: return SGPR_256RegClassID;
667   case OPW512: return SGPR_512RegClassID;
668   }
669 }
670 
671 unsigned AMDGPUDisassembler::getTtmpClassId(const OpWidthTy Width) const {
672   using namespace AMDGPU;
673 
674   assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
675   switch (Width) {
676   default: // fall
677   case OPW32:
678   case OPW16:
679   case OPWV216:
680     return TTMP_32RegClassID;
681   case OPW64: return TTMP_64RegClassID;
682   case OPW128: return TTMP_128RegClassID;
683   case OPW256: return TTMP_256RegClassID;
684   case OPW512: return TTMP_512RegClassID;
685   }
686 }
687 
688 int AMDGPUDisassembler::getTTmpIdx(unsigned Val) const {
689   using namespace AMDGPU::EncValues;
690 
691   unsigned TTmpMin = isGFX9() ? TTMP_GFX9_MIN : TTMP_VI_MIN;
692   unsigned TTmpMax = isGFX9() ? TTMP_GFX9_MAX : TTMP_VI_MAX;
693 
694   return (TTmpMin <= Val && Val <= TTmpMax)? Val - TTmpMin : -1;
695 }
696 
697 MCOperand AMDGPUDisassembler::decodeSrcOp(const OpWidthTy Width, unsigned Val) const {
698   using namespace AMDGPU::EncValues;
699 
700   assert(Val < 512); // enum9
701 
702   if (VGPR_MIN <= Val && Val <= VGPR_MAX) {
703     return createRegOperand(getVgprClassId(Width), Val - VGPR_MIN);
704   }
705   if (Val <= SGPR_MAX) {
706     assert(SGPR_MIN == 0); // "SGPR_MIN <= Val" is always true and causes compilation warning.
707     return createSRegOperand(getSgprClassId(Width), Val - SGPR_MIN);
708   }
709 
710   int TTmpIdx = getTTmpIdx(Val);
711   if (TTmpIdx >= 0) {
712     return createSRegOperand(getTtmpClassId(Width), TTmpIdx);
713   }
714 
715   if (INLINE_INTEGER_C_MIN <= Val && Val <= INLINE_INTEGER_C_MAX)
716     return decodeIntImmed(Val);
717 
718   if (INLINE_FLOATING_C_MIN <= Val && Val <= INLINE_FLOATING_C_MAX)
719     return decodeFPImmed(Width, Val);
720 
721   if (Val == LITERAL_CONST)
722     return decodeLiteralConstant();
723 
724   switch (Width) {
725   case OPW32:
726   case OPW16:
727   case OPWV216:
728     return decodeSpecialReg32(Val);
729   case OPW64:
730     return decodeSpecialReg64(Val);
731   default:
732     llvm_unreachable("unexpected immediate type");
733   }
734 }
735 
736 MCOperand AMDGPUDisassembler::decodeDstOp(const OpWidthTy Width, unsigned Val) const {
737   using namespace AMDGPU::EncValues;
738 
739   assert(Val < 128);
740   assert(Width == OPW256 || Width == OPW512);
741 
742   if (Val <= SGPR_MAX) {
743     assert(SGPR_MIN == 0); // "SGPR_MIN <= Val" is always true and causes compilation warning.
744     return createSRegOperand(getSgprClassId(Width), Val - SGPR_MIN);
745   }
746 
747   int TTmpIdx = getTTmpIdx(Val);
748   if (TTmpIdx >= 0) {
749     return createSRegOperand(getTtmpClassId(Width), TTmpIdx);
750   }
751 
752   llvm_unreachable("unknown dst register");
753 }
754 
755 MCOperand AMDGPUDisassembler::decodeSpecialReg32(unsigned Val) const {
756   using namespace AMDGPU;
757 
758   switch (Val) {
759   case 102: return createRegOperand(FLAT_SCR_LO);
760   case 103: return createRegOperand(FLAT_SCR_HI);
761   case 104: return createRegOperand(XNACK_MASK_LO);
762   case 105: return createRegOperand(XNACK_MASK_HI);
763   case 106: return createRegOperand(VCC_LO);
764   case 107: return createRegOperand(VCC_HI);
765   case 108: assert(!isGFX9()); return createRegOperand(TBA_LO);
766   case 109: assert(!isGFX9()); return createRegOperand(TBA_HI);
767   case 110: assert(!isGFX9()); return createRegOperand(TMA_LO);
768   case 111: assert(!isGFX9()); return createRegOperand(TMA_HI);
769   case 124: return createRegOperand(M0);
770   case 126: return createRegOperand(EXEC_LO);
771   case 127: return createRegOperand(EXEC_HI);
772   case 235: return createRegOperand(SRC_SHARED_BASE);
773   case 236: return createRegOperand(SRC_SHARED_LIMIT);
774   case 237: return createRegOperand(SRC_PRIVATE_BASE);
775   case 238: return createRegOperand(SRC_PRIVATE_LIMIT);
776     // TODO: SRC_POPS_EXITING_WAVE_ID
777     // ToDo: no support for vccz register
778   case 251: break;
779     // ToDo: no support for execz register
780   case 252: break;
781   case 253: return createRegOperand(SCC);
782   default: break;
783   }
784   return errOperand(Val, "unknown operand encoding " + Twine(Val));
785 }
786 
787 MCOperand AMDGPUDisassembler::decodeSpecialReg64(unsigned Val) const {
788   using namespace AMDGPU;
789 
790   switch (Val) {
791   case 102: return createRegOperand(FLAT_SCR);
792   case 104: return createRegOperand(XNACK_MASK);
793   case 106: return createRegOperand(VCC);
794   case 108: assert(!isGFX9()); return createRegOperand(TBA);
795   case 110: assert(!isGFX9()); return createRegOperand(TMA);
796   case 126: return createRegOperand(EXEC);
797   default: break;
798   }
799   return errOperand(Val, "unknown operand encoding " + Twine(Val));
800 }
801 
802 MCOperand AMDGPUDisassembler::decodeSDWASrc(const OpWidthTy Width,
803                                             const unsigned Val) const {
804   using namespace AMDGPU::SDWA;
805   using namespace AMDGPU::EncValues;
806 
807   if (STI.getFeatureBits()[AMDGPU::FeatureGFX9]) {
808     // XXX: static_cast<int> is needed to avoid stupid warning:
809     // compare with unsigned is always true
810     if (SDWA9EncValues::SRC_VGPR_MIN <= static_cast<int>(Val) &&
811         Val <= SDWA9EncValues::SRC_VGPR_MAX) {
812       return createRegOperand(getVgprClassId(Width),
813                               Val - SDWA9EncValues::SRC_VGPR_MIN);
814     }
815     if (SDWA9EncValues::SRC_SGPR_MIN <= Val &&
816         Val <= SDWA9EncValues::SRC_SGPR_MAX) {
817       return createSRegOperand(getSgprClassId(Width),
818                                Val - SDWA9EncValues::SRC_SGPR_MIN);
819     }
820     if (SDWA9EncValues::SRC_TTMP_MIN <= Val &&
821         Val <= SDWA9EncValues::SRC_TTMP_MAX) {
822       return createSRegOperand(getTtmpClassId(Width),
823                                Val - SDWA9EncValues::SRC_TTMP_MIN);
824     }
825 
826     const unsigned SVal = Val - SDWA9EncValues::SRC_SGPR_MIN;
827 
828     if (INLINE_INTEGER_C_MIN <= SVal && SVal <= INLINE_INTEGER_C_MAX)
829       return decodeIntImmed(SVal);
830 
831     if (INLINE_FLOATING_C_MIN <= SVal && SVal <= INLINE_FLOATING_C_MAX)
832       return decodeFPImmed(Width, SVal);
833 
834     return decodeSpecialReg32(SVal);
835   } else if (STI.getFeatureBits()[AMDGPU::FeatureVolcanicIslands]) {
836     return createRegOperand(getVgprClassId(Width), Val);
837   }
838   llvm_unreachable("unsupported target");
839 }
840 
841 MCOperand AMDGPUDisassembler::decodeSDWASrc16(unsigned Val) const {
842   return decodeSDWASrc(OPW16, Val);
843 }
844 
845 MCOperand AMDGPUDisassembler::decodeSDWASrc32(unsigned Val) const {
846   return decodeSDWASrc(OPW32, Val);
847 }
848 
849 MCOperand AMDGPUDisassembler::decodeSDWAVopcDst(unsigned Val) const {
850   using namespace AMDGPU::SDWA;
851 
852   assert(STI.getFeatureBits()[AMDGPU::FeatureGFX9] &&
853          "SDWAVopcDst should be present only on GFX9");
854   if (Val & SDWA9EncValues::VOPC_DST_VCC_MASK) {
855     Val &= SDWA9EncValues::VOPC_DST_SGPR_MASK;
856 
857     int TTmpIdx = getTTmpIdx(Val);
858     if (TTmpIdx >= 0) {
859       return createSRegOperand(getTtmpClassId(OPW64), TTmpIdx);
860     } else if (Val > AMDGPU::EncValues::SGPR_MAX) {
861       return decodeSpecialReg64(Val);
862     } else {
863       return createSRegOperand(getSgprClassId(OPW64), Val);
864     }
865   } else {
866     return createRegOperand(AMDGPU::VCC);
867   }
868 }
869 
870 bool AMDGPUDisassembler::isVI() const {
871   return STI.getFeatureBits()[AMDGPU::FeatureVolcanicIslands];
872 }
873 
874 bool AMDGPUDisassembler::isGFX9() const {
875   return STI.getFeatureBits()[AMDGPU::FeatureGFX9];
876 }
877 
878 //===----------------------------------------------------------------------===//
879 // AMDGPUSymbolizer
880 //===----------------------------------------------------------------------===//
881 
882 // Try to find symbol name for specified label
883 bool AMDGPUSymbolizer::tryAddingSymbolicOperand(MCInst &Inst,
884                                 raw_ostream &/*cStream*/, int64_t Value,
885                                 uint64_t /*Address*/, bool IsBranch,
886                                 uint64_t /*Offset*/, uint64_t /*InstSize*/) {
887   using SymbolInfoTy = std::tuple<uint64_t, StringRef, uint8_t>;
888   using SectionSymbolsTy = std::vector<SymbolInfoTy>;
889 
890   if (!IsBranch) {
891     return false;
892   }
893 
894   auto *Symbols = static_cast<SectionSymbolsTy *>(DisInfo);
895   if (!Symbols)
896     return false;
897 
898   auto Result = std::find_if(Symbols->begin(), Symbols->end(),
899                              [Value](const SymbolInfoTy& Val) {
900                                 return std::get<0>(Val) == static_cast<uint64_t>(Value)
901                                     && std::get<2>(Val) == ELF::STT_NOTYPE;
902                              });
903   if (Result != Symbols->end()) {
904     auto *Sym = Ctx.getOrCreateSymbol(std::get<1>(*Result));
905     const auto *Add = MCSymbolRefExpr::create(Sym, Ctx);
906     Inst.addOperand(MCOperand::createExpr(Add));
907     return true;
908   }
909   return false;
910 }
911 
912 void AMDGPUSymbolizer::tryAddingPcLoadReferenceComment(raw_ostream &cStream,
913                                                        int64_t Value,
914                                                        uint64_t Address) {
915   llvm_unreachable("unimplemented");
916 }
917 
918 //===----------------------------------------------------------------------===//
919 // Initialization
920 //===----------------------------------------------------------------------===//
921 
922 static MCSymbolizer *createAMDGPUSymbolizer(const Triple &/*TT*/,
923                               LLVMOpInfoCallback /*GetOpInfo*/,
924                               LLVMSymbolLookupCallback /*SymbolLookUp*/,
925                               void *DisInfo,
926                               MCContext *Ctx,
927                               std::unique_ptr<MCRelocationInfo> &&RelInfo) {
928   return new AMDGPUSymbolizer(*Ctx, std::move(RelInfo), DisInfo);
929 }
930 
931 static MCDisassembler *createAMDGPUDisassembler(const Target &T,
932                                                 const MCSubtargetInfo &STI,
933                                                 MCContext &Ctx) {
934   return new AMDGPUDisassembler(STI, Ctx, T.createMCInstrInfo());
935 }
936 
937 extern "C" void LLVMInitializeAMDGPUDisassembler() {
938   TargetRegistry::RegisterMCDisassembler(getTheGCNTarget(),
939                                          createAMDGPUDisassembler);
940   TargetRegistry::RegisterMCSymbolizer(getTheGCNTarget(),
941                                        createAMDGPUSymbolizer);
942 }
943