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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 "MCTargetDesc/AMDGPUMCTargetDesc.h"
24 #include "SIDefines.h"
25 #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
26 #include "Utils/AMDGPUBaseInfo.h"
27 #include "llvm-c/Disassembler.h"
28 #include "llvm/ADT/APInt.h"
29 #include "llvm/ADT/ArrayRef.h"
30 #include "llvm/ADT/Twine.h"
31 #include "llvm/BinaryFormat/ELF.h"
32 #include "llvm/MC/MCContext.h"
33 #include "llvm/MC/MCDisassembler/MCDisassembler.h"
34 #include "llvm/MC/MCExpr.h"
35 #include "llvm/MC/MCFixedLenDisassembler.h"
36 #include "llvm/MC/MCInst.h"
37 #include "llvm/MC/MCSubtargetInfo.h"
38 #include "llvm/Support/Endian.h"
39 #include "llvm/Support/ErrorHandling.h"
40 #include "llvm/Support/MathExtras.h"
41 #include "llvm/Support/TargetRegistry.h"
42 #include "llvm/Support/raw_ostream.h"
43 #include <algorithm>
44 #include <cassert>
45 #include <cstddef>
46 #include <cstdint>
47 #include <iterator>
48 #include <tuple>
49 #include <vector>
50 
51 using namespace llvm;
52 
53 #define DEBUG_TYPE "amdgpu-disassembler"
54 
55 using DecodeStatus = llvm::MCDisassembler::DecodeStatus;
56 
57 inline static MCDisassembler::DecodeStatus
addOperand(MCInst & Inst,const MCOperand & Opnd)58 addOperand(MCInst &Inst, const MCOperand& Opnd) {
59   Inst.addOperand(Opnd);
60   return Opnd.isValid() ?
61     MCDisassembler::Success :
62     MCDisassembler::SoftFail;
63 }
64 
insertNamedMCOperand(MCInst & MI,const MCOperand & Op,uint16_t NameIdx)65 static int insertNamedMCOperand(MCInst &MI, const MCOperand &Op,
66                                 uint16_t NameIdx) {
67   int OpIdx = AMDGPU::getNamedOperandIdx(MI.getOpcode(), NameIdx);
68   if (OpIdx != -1) {
69     auto I = MI.begin();
70     std::advance(I, OpIdx);
71     MI.insert(I, Op);
72   }
73   return OpIdx;
74 }
75 
decodeSoppBrTarget(MCInst & Inst,unsigned Imm,uint64_t Addr,const void * Decoder)76 static DecodeStatus decodeSoppBrTarget(MCInst &Inst, unsigned Imm,
77                                        uint64_t Addr, const void *Decoder) {
78   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder);
79 
80   APInt SignedOffset(18, Imm * 4, true);
81   int64_t Offset = (SignedOffset.sext(64) + 4 + Addr).getSExtValue();
82 
83   if (DAsm->tryAddingSymbolicOperand(Inst, Offset, Addr, true, 2, 2))
84     return MCDisassembler::Success;
85   return addOperand(Inst, MCOperand::createImm(Imm));
86 }
87 
88 #define DECODE_OPERAND(StaticDecoderName, DecoderName) \
89 static DecodeStatus StaticDecoderName(MCInst &Inst, \
90                                        unsigned Imm, \
91                                        uint64_t /*Addr*/, \
92                                        const void *Decoder) { \
93   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder); \
94   return addOperand(Inst, DAsm->DecoderName(Imm)); \
95 }
96 
97 #define DECODE_OPERAND_REG(RegClass) \
98 DECODE_OPERAND(Decode##RegClass##RegisterClass, decodeOperand_##RegClass)
99 
100 DECODE_OPERAND_REG(VGPR_32)
DECODE_OPERAND_REG(VS_32)101 DECODE_OPERAND_REG(VS_32)
102 DECODE_OPERAND_REG(VS_64)
103 DECODE_OPERAND_REG(VS_128)
104 
105 DECODE_OPERAND_REG(VReg_64)
106 DECODE_OPERAND_REG(VReg_96)
107 DECODE_OPERAND_REG(VReg_128)
108 
109 DECODE_OPERAND_REG(SReg_32)
110 DECODE_OPERAND_REG(SReg_32_XM0_XEXEC)
111 DECODE_OPERAND_REG(SReg_32_XEXEC_HI)
112 DECODE_OPERAND_REG(SReg_64)
113 DECODE_OPERAND_REG(SReg_64_XEXEC)
114 DECODE_OPERAND_REG(SReg_128)
115 DECODE_OPERAND_REG(SReg_256)
116 DECODE_OPERAND_REG(SReg_512)
117 
118 static DecodeStatus decodeOperand_VSrc16(MCInst &Inst,
119                                          unsigned Imm,
120                                          uint64_t Addr,
121                                          const void *Decoder) {
122   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder);
123   return addOperand(Inst, DAsm->decodeOperand_VSrc16(Imm));
124 }
125 
decodeOperand_VSrcV216(MCInst & Inst,unsigned Imm,uint64_t Addr,const void * Decoder)126 static DecodeStatus decodeOperand_VSrcV216(MCInst &Inst,
127                                          unsigned Imm,
128                                          uint64_t Addr,
129                                          const void *Decoder) {
130   auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder);
131   return addOperand(Inst, DAsm->decodeOperand_VSrcV216(Imm));
132 }
133 
134 #define DECODE_SDWA(DecName) \
135 DECODE_OPERAND(decodeSDWA##DecName, decodeSDWA##DecName)
136 
137 DECODE_SDWA(Src32)
DECODE_SDWA(Src16)138 DECODE_SDWA(Src16)
139 DECODE_SDWA(VopcDst)
140 
141 #include "AMDGPUGenDisassemblerTables.inc"
142 
143 //===----------------------------------------------------------------------===//
144 //
145 //===----------------------------------------------------------------------===//
146 
147 template <typename T> static inline T eatBytes(ArrayRef<uint8_t>& Bytes) {
148   assert(Bytes.size() >= sizeof(T));
149   const auto Res = support::endian::read<T, support::endianness::little>(Bytes.data());
150   Bytes = Bytes.slice(sizeof(T));
151   return Res;
152 }
153 
tryDecodeInst(const uint8_t * Table,MCInst & MI,uint64_t Inst,uint64_t Address) const154 DecodeStatus AMDGPUDisassembler::tryDecodeInst(const uint8_t* Table,
155                                                MCInst &MI,
156                                                uint64_t Inst,
157                                                uint64_t Address) const {
158   assert(MI.getOpcode() == 0);
159   assert(MI.getNumOperands() == 0);
160   MCInst TmpInst;
161   HasLiteral = false;
162   const auto SavedBytes = Bytes;
163   if (decodeInstruction(Table, TmpInst, Inst, Address, this, STI)) {
164     MI = TmpInst;
165     return MCDisassembler::Success;
166   }
167   Bytes = SavedBytes;
168   return MCDisassembler::Fail;
169 }
170 
getInstruction(MCInst & MI,uint64_t & Size,ArrayRef<uint8_t> Bytes_,uint64_t Address,raw_ostream & WS,raw_ostream & CS) const171 DecodeStatus AMDGPUDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
172                                                 ArrayRef<uint8_t> Bytes_,
173                                                 uint64_t Address,
174                                                 raw_ostream &WS,
175                                                 raw_ostream &CS) const {
176   CommentStream = &CS;
177   bool IsSDWA = false;
178 
179   // ToDo: AMDGPUDisassembler supports only VI ISA.
180   if (!STI.getFeatureBits()[AMDGPU::FeatureGCN3Encoding])
181     report_fatal_error("Disassembly not yet supported for subtarget");
182 
183   const unsigned MaxInstBytesNum = (std::min)((size_t)8, Bytes_.size());
184   Bytes = Bytes_.slice(0, MaxInstBytesNum);
185 
186   DecodeStatus Res = MCDisassembler::Fail;
187   do {
188     // ToDo: better to switch encoding length using some bit predicate
189     // but it is unknown yet, so try all we can
190 
191     // Try to decode DPP and SDWA first to solve conflict with VOP1 and VOP2
192     // encodings
193     if (Bytes.size() >= 8) {
194       const uint64_t QW = eatBytes<uint64_t>(Bytes);
195       Res = tryDecodeInst(DecoderTableDPP64, MI, QW, Address);
196       if (Res) break;
197 
198       Res = tryDecodeInst(DecoderTableSDWA64, MI, QW, Address);
199       if (Res) { IsSDWA = true;  break; }
200 
201       Res = tryDecodeInst(DecoderTableSDWA964, MI, QW, Address);
202       if (Res) { IsSDWA = true;  break; }
203 
204       if (STI.getFeatureBits()[AMDGPU::FeatureUnpackedD16VMem]) {
205         Res = tryDecodeInst(DecoderTableGFX80_UNPACKED64, MI, QW, Address);
206         if (Res)
207           break;
208       }
209 
210       // Some GFX9 subtargets repurposed the v_mad_mix_f32, v_mad_mixlo_f16 and
211       // v_mad_mixhi_f16 for FMA variants. Try to decode using this special
212       // table first so we print the correct name.
213       if (STI.getFeatureBits()[AMDGPU::FeatureFmaMixInsts]) {
214         Res = tryDecodeInst(DecoderTableGFX9_DL64, MI, QW, Address);
215         if (Res)
216           break;
217       }
218     }
219 
220     // Reinitialize Bytes as DPP64 could have eaten too much
221     Bytes = Bytes_.slice(0, MaxInstBytesNum);
222 
223     // Try decode 32-bit instruction
224     if (Bytes.size() < 4) break;
225     const uint32_t DW = eatBytes<uint32_t>(Bytes);
226     Res = tryDecodeInst(DecoderTableVI32, MI, DW, Address);
227     if (Res) break;
228 
229     Res = tryDecodeInst(DecoderTableAMDGPU32, MI, DW, Address);
230     if (Res) break;
231 
232     Res = tryDecodeInst(DecoderTableGFX932, MI, DW, Address);
233     if (Res) break;
234 
235     if (Bytes.size() < 4) break;
236     const uint64_t QW = ((uint64_t)eatBytes<uint32_t>(Bytes) << 32) | DW;
237     Res = tryDecodeInst(DecoderTableVI64, MI, QW, Address);
238     if (Res) break;
239 
240     Res = tryDecodeInst(DecoderTableAMDGPU64, MI, QW, Address);
241     if (Res) break;
242 
243     Res = tryDecodeInst(DecoderTableGFX964, MI, QW, Address);
244   } while (false);
245 
246   if (Res && (MI.getOpcode() == AMDGPU::V_MAC_F32_e64_vi ||
247               MI.getOpcode() == AMDGPU::V_MAC_F32_e64_si ||
248               MI.getOpcode() == AMDGPU::V_MAC_F16_e64_vi ||
249               MI.getOpcode() == AMDGPU::V_FMAC_F32_e64_vi)) {
250     // Insert dummy unused src2_modifiers.
251     insertNamedMCOperand(MI, MCOperand::createImm(0),
252                          AMDGPU::OpName::src2_modifiers);
253   }
254 
255   if (Res && (MCII->get(MI.getOpcode()).TSFlags & SIInstrFlags::MIMG)) {
256     Res = convertMIMGInst(MI);
257   }
258 
259   if (Res && IsSDWA)
260     Res = convertSDWAInst(MI);
261 
262   // if the opcode was not recognized we'll assume a Size of 4 bytes
263   // (unless there are fewer bytes left)
264   Size = Res ? (MaxInstBytesNum - Bytes.size())
265              : std::min((size_t)4, Bytes_.size());
266   return Res;
267 }
268 
convertSDWAInst(MCInst & MI) const269 DecodeStatus AMDGPUDisassembler::convertSDWAInst(MCInst &MI) const {
270   if (STI.getFeatureBits()[AMDGPU::FeatureGFX9]) {
271     if (AMDGPU::getNamedOperandIdx(MI.getOpcode(), AMDGPU::OpName::sdst) != -1)
272       // VOPC - insert clamp
273       insertNamedMCOperand(MI, MCOperand::createImm(0), AMDGPU::OpName::clamp);
274   } else if (STI.getFeatureBits()[AMDGPU::FeatureVolcanicIslands]) {
275     int SDst = AMDGPU::getNamedOperandIdx(MI.getOpcode(), AMDGPU::OpName::sdst);
276     if (SDst != -1) {
277       // VOPC - insert VCC register as sdst
278       insertNamedMCOperand(MI, createRegOperand(AMDGPU::VCC),
279                            AMDGPU::OpName::sdst);
280     } else {
281       // VOP1/2 - insert omod if present in instruction
282       insertNamedMCOperand(MI, MCOperand::createImm(0), AMDGPU::OpName::omod);
283     }
284   }
285   return MCDisassembler::Success;
286 }
287 
288 // Note that MIMG format provides no information about VADDR size.
289 // Consequently, decoded instructions always show address
290 // as if it has 1 dword, which could be not really so.
convertMIMGInst(MCInst & MI) const291 DecodeStatus AMDGPUDisassembler::convertMIMGInst(MCInst &MI) const {
292 
293   int VDstIdx = AMDGPU::getNamedOperandIdx(MI.getOpcode(),
294                                            AMDGPU::OpName::vdst);
295 
296   int VDataIdx = AMDGPU::getNamedOperandIdx(MI.getOpcode(),
297                                             AMDGPU::OpName::vdata);
298 
299   int DMaskIdx = AMDGPU::getNamedOperandIdx(MI.getOpcode(),
300                                             AMDGPU::OpName::dmask);
301 
302   int TFEIdx   = AMDGPU::getNamedOperandIdx(MI.getOpcode(),
303                                             AMDGPU::OpName::tfe);
304   int D16Idx   = AMDGPU::getNamedOperandIdx(MI.getOpcode(),
305                                             AMDGPU::OpName::d16);
306 
307   assert(VDataIdx != -1);
308   assert(DMaskIdx != -1);
309   assert(TFEIdx != -1);
310 
311   bool IsAtomic = (VDstIdx != -1);
312   bool IsGather4 = MCII->get(MI.getOpcode()).TSFlags & SIInstrFlags::Gather4;
313 
314   unsigned DMask = MI.getOperand(DMaskIdx).getImm() & 0xf;
315   if (DMask == 0)
316     return MCDisassembler::Success;
317 
318   unsigned DstSize = IsGather4 ? 4 : countPopulation(DMask);
319   if (DstSize == 1)
320     return MCDisassembler::Success;
321 
322   bool D16 = D16Idx >= 0 && MI.getOperand(D16Idx).getImm();
323   if (D16 && AMDGPU::hasPackedD16(STI)) {
324     DstSize = (DstSize + 1) / 2;
325   }
326 
327   // FIXME: Add tfe support
328   if (MI.getOperand(TFEIdx).getImm())
329     return MCDisassembler::Success;
330 
331   int NewOpcode = -1;
332 
333   if (IsGather4) {
334     if (D16 && AMDGPU::hasPackedD16(STI))
335       NewOpcode = AMDGPU::getMaskedMIMGOp(MI.getOpcode(), 2);
336     else
337       return MCDisassembler::Success;
338   } else {
339     NewOpcode = AMDGPU::getMaskedMIMGOp(MI.getOpcode(), DstSize);
340     if (NewOpcode == -1)
341       return MCDisassembler::Success;
342   }
343 
344   auto RCID = MCII->get(NewOpcode).OpInfo[VDataIdx].RegClass;
345 
346   // Get first subregister of VData
347   unsigned Vdata0 = MI.getOperand(VDataIdx).getReg();
348   unsigned VdataSub0 = MRI.getSubReg(Vdata0, AMDGPU::sub0);
349   Vdata0 = (VdataSub0 != 0)? VdataSub0 : Vdata0;
350 
351   // Widen the register to the correct number of enabled channels.
352   auto NewVdata = MRI.getMatchingSuperReg(Vdata0, AMDGPU::sub0,
353                                           &MRI.getRegClass(RCID));
354   if (NewVdata == AMDGPU::NoRegister) {
355     // It's possible to encode this such that the low register + enabled
356     // components exceeds the register count.
357     return MCDisassembler::Success;
358   }
359 
360   MI.setOpcode(NewOpcode);
361   // vaddr will be always appear as a single VGPR. This will look different than
362   // how it is usually emitted because the number of register components is not
363   // in the instruction encoding.
364   MI.getOperand(VDataIdx) = MCOperand::createReg(NewVdata);
365 
366   if (IsAtomic) {
367     // Atomic operations have an additional operand (a copy of data)
368     MI.getOperand(VDstIdx) = MCOperand::createReg(NewVdata);
369   }
370 
371   return MCDisassembler::Success;
372 }
373 
getRegClassName(unsigned RegClassID) const374 const char* AMDGPUDisassembler::getRegClassName(unsigned RegClassID) const {
375   return getContext().getRegisterInfo()->
376     getRegClassName(&AMDGPUMCRegisterClasses[RegClassID]);
377 }
378 
379 inline
errOperand(unsigned V,const Twine & ErrMsg) const380 MCOperand AMDGPUDisassembler::errOperand(unsigned V,
381                                          const Twine& ErrMsg) const {
382   *CommentStream << "Error: " + ErrMsg;
383 
384   // ToDo: add support for error operands to MCInst.h
385   // return MCOperand::createError(V);
386   return MCOperand();
387 }
388 
389 inline
createRegOperand(unsigned int RegId) const390 MCOperand AMDGPUDisassembler::createRegOperand(unsigned int RegId) const {
391   return MCOperand::createReg(AMDGPU::getMCReg(RegId, STI));
392 }
393 
394 inline
createRegOperand(unsigned RegClassID,unsigned Val) const395 MCOperand AMDGPUDisassembler::createRegOperand(unsigned RegClassID,
396                                                unsigned Val) const {
397   const auto& RegCl = AMDGPUMCRegisterClasses[RegClassID];
398   if (Val >= RegCl.getNumRegs())
399     return errOperand(Val, Twine(getRegClassName(RegClassID)) +
400                            ": unknown register " + Twine(Val));
401   return createRegOperand(RegCl.getRegister(Val));
402 }
403 
404 inline
createSRegOperand(unsigned SRegClassID,unsigned Val) const405 MCOperand AMDGPUDisassembler::createSRegOperand(unsigned SRegClassID,
406                                                 unsigned Val) const {
407   // ToDo: SI/CI have 104 SGPRs, VI - 102
408   // Valery: here we accepting as much as we can, let assembler sort it out
409   int shift = 0;
410   switch (SRegClassID) {
411   case AMDGPU::SGPR_32RegClassID:
412   case AMDGPU::TTMP_32RegClassID:
413     break;
414   case AMDGPU::SGPR_64RegClassID:
415   case AMDGPU::TTMP_64RegClassID:
416     shift = 1;
417     break;
418   case AMDGPU::SGPR_128RegClassID:
419   case AMDGPU::TTMP_128RegClassID:
420   // ToDo: unclear if s[100:104] is available on VI. Can we use VCC as SGPR in
421   // this bundle?
422   case AMDGPU::SGPR_256RegClassID:
423   case AMDGPU::TTMP_256RegClassID:
424     // ToDo: unclear if s[96:104] is available on VI. Can we use VCC as SGPR in
425   // this bundle?
426   case AMDGPU::SGPR_512RegClassID:
427   case AMDGPU::TTMP_512RegClassID:
428     shift = 2;
429     break;
430   // ToDo: unclear if s[88:104] is available on VI. Can we use VCC as SGPR in
431   // this bundle?
432   default:
433     llvm_unreachable("unhandled register class");
434   }
435 
436   if (Val % (1 << shift)) {
437     *CommentStream << "Warning: " << getRegClassName(SRegClassID)
438                    << ": scalar reg isn't aligned " << Val;
439   }
440 
441   return createRegOperand(SRegClassID, Val >> shift);
442 }
443 
decodeOperand_VS_32(unsigned Val) const444 MCOperand AMDGPUDisassembler::decodeOperand_VS_32(unsigned Val) const {
445   return decodeSrcOp(OPW32, Val);
446 }
447 
decodeOperand_VS_64(unsigned Val) const448 MCOperand AMDGPUDisassembler::decodeOperand_VS_64(unsigned Val) const {
449   return decodeSrcOp(OPW64, Val);
450 }
451 
decodeOperand_VS_128(unsigned Val) const452 MCOperand AMDGPUDisassembler::decodeOperand_VS_128(unsigned Val) const {
453   return decodeSrcOp(OPW128, Val);
454 }
455 
decodeOperand_VSrc16(unsigned Val) const456 MCOperand AMDGPUDisassembler::decodeOperand_VSrc16(unsigned Val) const {
457   return decodeSrcOp(OPW16, Val);
458 }
459 
decodeOperand_VSrcV216(unsigned Val) const460 MCOperand AMDGPUDisassembler::decodeOperand_VSrcV216(unsigned Val) const {
461   return decodeSrcOp(OPWV216, Val);
462 }
463 
decodeOperand_VGPR_32(unsigned Val) const464 MCOperand AMDGPUDisassembler::decodeOperand_VGPR_32(unsigned Val) const {
465   // Some instructions have operand restrictions beyond what the encoding
466   // allows. Some ordinarily VSrc_32 operands are VGPR_32, so clear the extra
467   // high bit.
468   Val &= 255;
469 
470   return createRegOperand(AMDGPU::VGPR_32RegClassID, Val);
471 }
472 
decodeOperand_VReg_64(unsigned Val) const473 MCOperand AMDGPUDisassembler::decodeOperand_VReg_64(unsigned Val) const {
474   return createRegOperand(AMDGPU::VReg_64RegClassID, Val);
475 }
476 
decodeOperand_VReg_96(unsigned Val) const477 MCOperand AMDGPUDisassembler::decodeOperand_VReg_96(unsigned Val) const {
478   return createRegOperand(AMDGPU::VReg_96RegClassID, Val);
479 }
480 
decodeOperand_VReg_128(unsigned Val) const481 MCOperand AMDGPUDisassembler::decodeOperand_VReg_128(unsigned Val) const {
482   return createRegOperand(AMDGPU::VReg_128RegClassID, Val);
483 }
484 
decodeOperand_SReg_32(unsigned Val) const485 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32(unsigned Val) const {
486   // table-gen generated disassembler doesn't care about operand types
487   // leaving only registry class so SSrc_32 operand turns into SReg_32
488   // and therefore we accept immediates and literals here as well
489   return decodeSrcOp(OPW32, Val);
490 }
491 
decodeOperand_SReg_32_XM0_XEXEC(unsigned Val) const492 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32_XM0_XEXEC(
493   unsigned Val) const {
494   // SReg_32_XM0 is SReg_32 without M0 or EXEC_LO/EXEC_HI
495   return decodeOperand_SReg_32(Val);
496 }
497 
decodeOperand_SReg_32_XEXEC_HI(unsigned Val) const498 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32_XEXEC_HI(
499   unsigned Val) const {
500   // SReg_32_XM0 is SReg_32 without EXEC_HI
501   return decodeOperand_SReg_32(Val);
502 }
503 
decodeOperand_SReg_64(unsigned Val) const504 MCOperand AMDGPUDisassembler::decodeOperand_SReg_64(unsigned Val) const {
505   return decodeSrcOp(OPW64, Val);
506 }
507 
decodeOperand_SReg_64_XEXEC(unsigned Val) const508 MCOperand AMDGPUDisassembler::decodeOperand_SReg_64_XEXEC(unsigned Val) const {
509   return decodeSrcOp(OPW64, Val);
510 }
511 
decodeOperand_SReg_128(unsigned Val) const512 MCOperand AMDGPUDisassembler::decodeOperand_SReg_128(unsigned Val) const {
513   return decodeSrcOp(OPW128, Val);
514 }
515 
decodeOperand_SReg_256(unsigned Val) const516 MCOperand AMDGPUDisassembler::decodeOperand_SReg_256(unsigned Val) const {
517   return decodeDstOp(OPW256, Val);
518 }
519 
decodeOperand_SReg_512(unsigned Val) const520 MCOperand AMDGPUDisassembler::decodeOperand_SReg_512(unsigned Val) const {
521   return decodeDstOp(OPW512, Val);
522 }
523 
decodeLiteralConstant() const524 MCOperand AMDGPUDisassembler::decodeLiteralConstant() const {
525   // For now all literal constants are supposed to be unsigned integer
526   // ToDo: deal with signed/unsigned 64-bit integer constants
527   // ToDo: deal with float/double constants
528   if (!HasLiteral) {
529     if (Bytes.size() < 4) {
530       return errOperand(0, "cannot read literal, inst bytes left " +
531                         Twine(Bytes.size()));
532     }
533     HasLiteral = true;
534     Literal = eatBytes<uint32_t>(Bytes);
535   }
536   return MCOperand::createImm(Literal);
537 }
538 
decodeIntImmed(unsigned Imm)539 MCOperand AMDGPUDisassembler::decodeIntImmed(unsigned Imm) {
540   using namespace AMDGPU::EncValues;
541 
542   assert(Imm >= INLINE_INTEGER_C_MIN && Imm <= INLINE_INTEGER_C_MAX);
543   return MCOperand::createImm((Imm <= INLINE_INTEGER_C_POSITIVE_MAX) ?
544     (static_cast<int64_t>(Imm) - INLINE_INTEGER_C_MIN) :
545     (INLINE_INTEGER_C_POSITIVE_MAX - static_cast<int64_t>(Imm)));
546       // Cast prevents negative overflow.
547 }
548 
getInlineImmVal32(unsigned Imm)549 static int64_t getInlineImmVal32(unsigned Imm) {
550   switch (Imm) {
551   case 240:
552     return FloatToBits(0.5f);
553   case 241:
554     return FloatToBits(-0.5f);
555   case 242:
556     return FloatToBits(1.0f);
557   case 243:
558     return FloatToBits(-1.0f);
559   case 244:
560     return FloatToBits(2.0f);
561   case 245:
562     return FloatToBits(-2.0f);
563   case 246:
564     return FloatToBits(4.0f);
565   case 247:
566     return FloatToBits(-4.0f);
567   case 248: // 1 / (2 * PI)
568     return 0x3e22f983;
569   default:
570     llvm_unreachable("invalid fp inline imm");
571   }
572 }
573 
getInlineImmVal64(unsigned Imm)574 static int64_t getInlineImmVal64(unsigned Imm) {
575   switch (Imm) {
576   case 240:
577     return DoubleToBits(0.5);
578   case 241:
579     return DoubleToBits(-0.5);
580   case 242:
581     return DoubleToBits(1.0);
582   case 243:
583     return DoubleToBits(-1.0);
584   case 244:
585     return DoubleToBits(2.0);
586   case 245:
587     return DoubleToBits(-2.0);
588   case 246:
589     return DoubleToBits(4.0);
590   case 247:
591     return DoubleToBits(-4.0);
592   case 248: // 1 / (2 * PI)
593     return 0x3fc45f306dc9c882;
594   default:
595     llvm_unreachable("invalid fp inline imm");
596   }
597 }
598 
getInlineImmVal16(unsigned Imm)599 static int64_t getInlineImmVal16(unsigned Imm) {
600   switch (Imm) {
601   case 240:
602     return 0x3800;
603   case 241:
604     return 0xB800;
605   case 242:
606     return 0x3C00;
607   case 243:
608     return 0xBC00;
609   case 244:
610     return 0x4000;
611   case 245:
612     return 0xC000;
613   case 246:
614     return 0x4400;
615   case 247:
616     return 0xC400;
617   case 248: // 1 / (2 * PI)
618     return 0x3118;
619   default:
620     llvm_unreachable("invalid fp inline imm");
621   }
622 }
623 
decodeFPImmed(OpWidthTy Width,unsigned Imm)624 MCOperand AMDGPUDisassembler::decodeFPImmed(OpWidthTy Width, unsigned Imm) {
625   assert(Imm >= AMDGPU::EncValues::INLINE_FLOATING_C_MIN
626       && Imm <= AMDGPU::EncValues::INLINE_FLOATING_C_MAX);
627 
628   // ToDo: case 248: 1/(2*PI) - is allowed only on VI
629   switch (Width) {
630   case OPW32:
631     return MCOperand::createImm(getInlineImmVal32(Imm));
632   case OPW64:
633     return MCOperand::createImm(getInlineImmVal64(Imm));
634   case OPW16:
635   case OPWV216:
636     return MCOperand::createImm(getInlineImmVal16(Imm));
637   default:
638     llvm_unreachable("implement me");
639   }
640 }
641 
getVgprClassId(const OpWidthTy Width) const642 unsigned AMDGPUDisassembler::getVgprClassId(const OpWidthTy Width) const {
643   using namespace AMDGPU;
644 
645   assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
646   switch (Width) {
647   default: // fall
648   case OPW32:
649   case OPW16:
650   case OPWV216:
651     return VGPR_32RegClassID;
652   case OPW64: return VReg_64RegClassID;
653   case OPW128: return VReg_128RegClassID;
654   }
655 }
656 
getSgprClassId(const OpWidthTy Width) const657 unsigned AMDGPUDisassembler::getSgprClassId(const OpWidthTy Width) const {
658   using namespace AMDGPU;
659 
660   assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
661   switch (Width) {
662   default: // fall
663   case OPW32:
664   case OPW16:
665   case OPWV216:
666     return SGPR_32RegClassID;
667   case OPW64: return SGPR_64RegClassID;
668   case OPW128: return SGPR_128RegClassID;
669   case OPW256: return SGPR_256RegClassID;
670   case OPW512: return SGPR_512RegClassID;
671   }
672 }
673 
getTtmpClassId(const OpWidthTy Width) const674 unsigned AMDGPUDisassembler::getTtmpClassId(const OpWidthTy Width) const {
675   using namespace AMDGPU;
676 
677   assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
678   switch (Width) {
679   default: // fall
680   case OPW32:
681   case OPW16:
682   case OPWV216:
683     return TTMP_32RegClassID;
684   case OPW64: return TTMP_64RegClassID;
685   case OPW128: return TTMP_128RegClassID;
686   case OPW256: return TTMP_256RegClassID;
687   case OPW512: return TTMP_512RegClassID;
688   }
689 }
690 
getTTmpIdx(unsigned Val) const691 int AMDGPUDisassembler::getTTmpIdx(unsigned Val) const {
692   using namespace AMDGPU::EncValues;
693 
694   unsigned TTmpMin = isGFX9() ? TTMP_GFX9_MIN : TTMP_VI_MIN;
695   unsigned TTmpMax = isGFX9() ? TTMP_GFX9_MAX : TTMP_VI_MAX;
696 
697   return (TTmpMin <= Val && Val <= TTmpMax)? Val - TTmpMin : -1;
698 }
699 
decodeSrcOp(const OpWidthTy Width,unsigned Val) const700 MCOperand AMDGPUDisassembler::decodeSrcOp(const OpWidthTy Width, unsigned Val) const {
701   using namespace AMDGPU::EncValues;
702 
703   assert(Val < 512); // enum9
704 
705   if (VGPR_MIN <= Val && Val <= VGPR_MAX) {
706     return createRegOperand(getVgprClassId(Width), Val - VGPR_MIN);
707   }
708   if (Val <= SGPR_MAX) {
709     assert(SGPR_MIN == 0); // "SGPR_MIN <= Val" is always true and causes compilation warning.
710     return createSRegOperand(getSgprClassId(Width), Val - SGPR_MIN);
711   }
712 
713   int TTmpIdx = getTTmpIdx(Val);
714   if (TTmpIdx >= 0) {
715     return createSRegOperand(getTtmpClassId(Width), TTmpIdx);
716   }
717 
718   if (INLINE_INTEGER_C_MIN <= Val && Val <= INLINE_INTEGER_C_MAX)
719     return decodeIntImmed(Val);
720 
721   if (INLINE_FLOATING_C_MIN <= Val && Val <= INLINE_FLOATING_C_MAX)
722     return decodeFPImmed(Width, Val);
723 
724   if (Val == LITERAL_CONST)
725     return decodeLiteralConstant();
726 
727   switch (Width) {
728   case OPW32:
729   case OPW16:
730   case OPWV216:
731     return decodeSpecialReg32(Val);
732   case OPW64:
733     return decodeSpecialReg64(Val);
734   default:
735     llvm_unreachable("unexpected immediate type");
736   }
737 }
738 
decodeDstOp(const OpWidthTy Width,unsigned Val) const739 MCOperand AMDGPUDisassembler::decodeDstOp(const OpWidthTy Width, unsigned Val) const {
740   using namespace AMDGPU::EncValues;
741 
742   assert(Val < 128);
743   assert(Width == OPW256 || Width == OPW512);
744 
745   if (Val <= SGPR_MAX) {
746     assert(SGPR_MIN == 0); // "SGPR_MIN <= Val" is always true and causes compilation warning.
747     return createSRegOperand(getSgprClassId(Width), Val - SGPR_MIN);
748   }
749 
750   int TTmpIdx = getTTmpIdx(Val);
751   if (TTmpIdx >= 0) {
752     return createSRegOperand(getTtmpClassId(Width), TTmpIdx);
753   }
754 
755   llvm_unreachable("unknown dst register");
756 }
757 
decodeSpecialReg32(unsigned Val) const758 MCOperand AMDGPUDisassembler::decodeSpecialReg32(unsigned Val) const {
759   using namespace AMDGPU;
760 
761   switch (Val) {
762   case 102: return createRegOperand(FLAT_SCR_LO);
763   case 103: return createRegOperand(FLAT_SCR_HI);
764   case 104: return createRegOperand(XNACK_MASK_LO);
765   case 105: return createRegOperand(XNACK_MASK_HI);
766   case 106: return createRegOperand(VCC_LO);
767   case 107: return createRegOperand(VCC_HI);
768   case 108: assert(!isGFX9()); return createRegOperand(TBA_LO);
769   case 109: assert(!isGFX9()); return createRegOperand(TBA_HI);
770   case 110: assert(!isGFX9()); return createRegOperand(TMA_LO);
771   case 111: assert(!isGFX9()); return createRegOperand(TMA_HI);
772   case 124: return createRegOperand(M0);
773   case 126: return createRegOperand(EXEC_LO);
774   case 127: return createRegOperand(EXEC_HI);
775   case 235: return createRegOperand(SRC_SHARED_BASE);
776   case 236: return createRegOperand(SRC_SHARED_LIMIT);
777   case 237: return createRegOperand(SRC_PRIVATE_BASE);
778   case 238: return createRegOperand(SRC_PRIVATE_LIMIT);
779     // TODO: SRC_POPS_EXITING_WAVE_ID
780     // ToDo: no support for vccz register
781   case 251: break;
782     // ToDo: no support for execz register
783   case 252: break;
784   case 253: return createRegOperand(SCC);
785   default: break;
786   }
787   return errOperand(Val, "unknown operand encoding " + Twine(Val));
788 }
789 
decodeSpecialReg64(unsigned Val) const790 MCOperand AMDGPUDisassembler::decodeSpecialReg64(unsigned Val) const {
791   using namespace AMDGPU;
792 
793   switch (Val) {
794   case 102: return createRegOperand(FLAT_SCR);
795   case 104: return createRegOperand(XNACK_MASK);
796   case 106: return createRegOperand(VCC);
797   case 108: assert(!isGFX9()); return createRegOperand(TBA);
798   case 110: assert(!isGFX9()); return createRegOperand(TMA);
799   case 126: return createRegOperand(EXEC);
800   default: break;
801   }
802   return errOperand(Val, "unknown operand encoding " + Twine(Val));
803 }
804 
decodeSDWASrc(const OpWidthTy Width,const unsigned Val) const805 MCOperand AMDGPUDisassembler::decodeSDWASrc(const OpWidthTy Width,
806                                             const unsigned Val) const {
807   using namespace AMDGPU::SDWA;
808   using namespace AMDGPU::EncValues;
809 
810   if (STI.getFeatureBits()[AMDGPU::FeatureGFX9]) {
811     // XXX: static_cast<int> is needed to avoid stupid warning:
812     // compare with unsigned is always true
813     if (SDWA9EncValues::SRC_VGPR_MIN <= static_cast<int>(Val) &&
814         Val <= SDWA9EncValues::SRC_VGPR_MAX) {
815       return createRegOperand(getVgprClassId(Width),
816                               Val - SDWA9EncValues::SRC_VGPR_MIN);
817     }
818     if (SDWA9EncValues::SRC_SGPR_MIN <= Val &&
819         Val <= SDWA9EncValues::SRC_SGPR_MAX) {
820       return createSRegOperand(getSgprClassId(Width),
821                                Val - SDWA9EncValues::SRC_SGPR_MIN);
822     }
823     if (SDWA9EncValues::SRC_TTMP_MIN <= Val &&
824         Val <= SDWA9EncValues::SRC_TTMP_MAX) {
825       return createSRegOperand(getTtmpClassId(Width),
826                                Val - SDWA9EncValues::SRC_TTMP_MIN);
827     }
828 
829     const unsigned SVal = Val - SDWA9EncValues::SRC_SGPR_MIN;
830 
831     if (INLINE_INTEGER_C_MIN <= SVal && SVal <= INLINE_INTEGER_C_MAX)
832       return decodeIntImmed(SVal);
833 
834     if (INLINE_FLOATING_C_MIN <= SVal && SVal <= INLINE_FLOATING_C_MAX)
835       return decodeFPImmed(Width, SVal);
836 
837     return decodeSpecialReg32(SVal);
838   } else if (STI.getFeatureBits()[AMDGPU::FeatureVolcanicIslands]) {
839     return createRegOperand(getVgprClassId(Width), Val);
840   }
841   llvm_unreachable("unsupported target");
842 }
843 
decodeSDWASrc16(unsigned Val) const844 MCOperand AMDGPUDisassembler::decodeSDWASrc16(unsigned Val) const {
845   return decodeSDWASrc(OPW16, Val);
846 }
847 
decodeSDWASrc32(unsigned Val) const848 MCOperand AMDGPUDisassembler::decodeSDWASrc32(unsigned Val) const {
849   return decodeSDWASrc(OPW32, Val);
850 }
851 
decodeSDWAVopcDst(unsigned Val) const852 MCOperand AMDGPUDisassembler::decodeSDWAVopcDst(unsigned Val) const {
853   using namespace AMDGPU::SDWA;
854 
855   assert(STI.getFeatureBits()[AMDGPU::FeatureGFX9] &&
856          "SDWAVopcDst should be present only on GFX9");
857   if (Val & SDWA9EncValues::VOPC_DST_VCC_MASK) {
858     Val &= SDWA9EncValues::VOPC_DST_SGPR_MASK;
859 
860     int TTmpIdx = getTTmpIdx(Val);
861     if (TTmpIdx >= 0) {
862       return createSRegOperand(getTtmpClassId(OPW64), TTmpIdx);
863     } else if (Val > AMDGPU::EncValues::SGPR_MAX) {
864       return decodeSpecialReg64(Val);
865     } else {
866       return createSRegOperand(getSgprClassId(OPW64), Val);
867     }
868   } else {
869     return createRegOperand(AMDGPU::VCC);
870   }
871 }
872 
isVI() const873 bool AMDGPUDisassembler::isVI() const {
874   return STI.getFeatureBits()[AMDGPU::FeatureVolcanicIslands];
875 }
876 
isGFX9() const877 bool AMDGPUDisassembler::isGFX9() const {
878   return STI.getFeatureBits()[AMDGPU::FeatureGFX9];
879 }
880 
881 //===----------------------------------------------------------------------===//
882 // AMDGPUSymbolizer
883 //===----------------------------------------------------------------------===//
884 
885 // Try to find symbol name for specified label
tryAddingSymbolicOperand(MCInst & Inst,raw_ostream &,int64_t Value,uint64_t,bool IsBranch,uint64_t,uint64_t)886 bool AMDGPUSymbolizer::tryAddingSymbolicOperand(MCInst &Inst,
887                                 raw_ostream &/*cStream*/, int64_t Value,
888                                 uint64_t /*Address*/, bool IsBranch,
889                                 uint64_t /*Offset*/, uint64_t /*InstSize*/) {
890   using SymbolInfoTy = std::tuple<uint64_t, StringRef, uint8_t>;
891   using SectionSymbolsTy = std::vector<SymbolInfoTy>;
892 
893   if (!IsBranch) {
894     return false;
895   }
896 
897   auto *Symbols = static_cast<SectionSymbolsTy *>(DisInfo);
898   if (!Symbols)
899     return false;
900 
901   auto Result = std::find_if(Symbols->begin(), Symbols->end(),
902                              [Value](const SymbolInfoTy& Val) {
903                                 return std::get<0>(Val) == static_cast<uint64_t>(Value)
904                                     && std::get<2>(Val) == ELF::STT_NOTYPE;
905                              });
906   if (Result != Symbols->end()) {
907     auto *Sym = Ctx.getOrCreateSymbol(std::get<1>(*Result));
908     const auto *Add = MCSymbolRefExpr::create(Sym, Ctx);
909     Inst.addOperand(MCOperand::createExpr(Add));
910     return true;
911   }
912   return false;
913 }
914 
tryAddingPcLoadReferenceComment(raw_ostream & cStream,int64_t Value,uint64_t Address)915 void AMDGPUSymbolizer::tryAddingPcLoadReferenceComment(raw_ostream &cStream,
916                                                        int64_t Value,
917                                                        uint64_t Address) {
918   llvm_unreachable("unimplemented");
919 }
920 
921 //===----------------------------------------------------------------------===//
922 // Initialization
923 //===----------------------------------------------------------------------===//
924 
createAMDGPUSymbolizer(const Triple &,LLVMOpInfoCallback,LLVMSymbolLookupCallback,void * DisInfo,MCContext * Ctx,std::unique_ptr<MCRelocationInfo> && RelInfo)925 static MCSymbolizer *createAMDGPUSymbolizer(const Triple &/*TT*/,
926                               LLVMOpInfoCallback /*GetOpInfo*/,
927                               LLVMSymbolLookupCallback /*SymbolLookUp*/,
928                               void *DisInfo,
929                               MCContext *Ctx,
930                               std::unique_ptr<MCRelocationInfo> &&RelInfo) {
931   return new AMDGPUSymbolizer(*Ctx, std::move(RelInfo), DisInfo);
932 }
933 
createAMDGPUDisassembler(const Target & T,const MCSubtargetInfo & STI,MCContext & Ctx)934 static MCDisassembler *createAMDGPUDisassembler(const Target &T,
935                                                 const MCSubtargetInfo &STI,
936                                                 MCContext &Ctx) {
937   return new AMDGPUDisassembler(STI, Ctx, T.createMCInstrInfo());
938 }
939 
LLVMInitializeAMDGPUDisassembler()940 extern "C" void LLVMInitializeAMDGPUDisassembler() {
941   TargetRegistry::RegisterMCDisassembler(getTheGCNTarget(),
942                                          createAMDGPUDisassembler);
943   TargetRegistry::RegisterMCSymbolizer(getTheGCNTarget(),
944                                        createAMDGPUSymbolizer);
945 }
946