1 //===-- AMDGPUDisassembler.cpp - Disassembler for AMDGPU ISA --------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 //===----------------------------------------------------------------------===//
14 /// This file contains definition for AMDGPU ISA disassembler
16 //===----------------------------------------------------------------------===//
18 // ToDo: What to do with instruction suffixes (v_mov_b32 vs v_mov_b32_e32)?
20 #include "AMDGPUDisassembler.h"
22 #include "AMDGPURegisterInfo.h"
23 #include "SIDefines.h"
24 #include "Utils/AMDGPUBaseInfo.h"
26 #include "llvm/MC/MCContext.h"
27 #include "llvm/MC/MCFixedLenDisassembler.h"
28 #include "llvm/MC/MCInst.h"
29 #include "llvm/MC/MCInstrDesc.h"
30 #include "llvm/MC/MCSubtargetInfo.h"
31 #include "llvm/Support/Endian.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/TargetRegistry.h"
38 #define DEBUG_TYPE "amdgpu-disassembler"
40 typedef llvm::MCDisassembler::DecodeStatus DecodeStatus;
43 inline static MCDisassembler::DecodeStatus
44 addOperand(MCInst &Inst, const MCOperand& Opnd) {
45 Inst.addOperand(Opnd);
46 return Opnd.isValid() ?
47 MCDisassembler::Success :
48 MCDisassembler::SoftFail;
51 #define DECODE_OPERAND2(RegClass, DecName) \
52 static DecodeStatus Decode##RegClass##RegisterClass(MCInst &Inst, \
55 const void *Decoder) { \
56 auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder); \
57 return addOperand(Inst, DAsm->decodeOperand_##DecName(Imm)); \
60 #define DECODE_OPERAND(RegClass) DECODE_OPERAND2(RegClass, RegClass)
62 DECODE_OPERAND(VGPR_32)
66 DECODE_OPERAND(VReg_64)
67 DECODE_OPERAND(VReg_96)
68 DECODE_OPERAND(VReg_128)
70 DECODE_OPERAND(SReg_32)
71 DECODE_OPERAND(SReg_32_XM0)
72 DECODE_OPERAND(SReg_64)
73 DECODE_OPERAND(SReg_128)
74 DECODE_OPERAND(SReg_256)
75 DECODE_OPERAND(SReg_512)
77 #define GET_SUBTARGETINFO_ENUM
78 #include "AMDGPUGenSubtargetInfo.inc"
79 #undef GET_SUBTARGETINFO_ENUM
81 #include "AMDGPUGenDisassemblerTables.inc"
83 //===----------------------------------------------------------------------===//
85 //===----------------------------------------------------------------------===//
87 template <typename T> static inline T eatBytes(ArrayRef<uint8_t>& Bytes) {
88 assert(Bytes.size() >= sizeof(T));
89 const auto Res = support::endian::read<T, support::endianness::little>(Bytes.data());
90 Bytes = Bytes.slice(sizeof(T));
94 DecodeStatus AMDGPUDisassembler::tryDecodeInst(const uint8_t* Table,
97 uint64_t Address) const {
98 assert(MI.getOpcode() == 0);
99 assert(MI.getNumOperands() == 0);
101 const auto SavedBytes = Bytes;
102 if (decodeInstruction(Table, TmpInst, Inst, Address, this, STI)) {
104 return MCDisassembler::Success;
107 return MCDisassembler::Fail;
110 DecodeStatus AMDGPUDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
111 ArrayRef<uint8_t> Bytes_,
114 raw_ostream &CS) const {
117 // ToDo: AMDGPUDisassembler supports only VI ISA.
118 assert(AMDGPU::isVI(STI) && "Can disassemble only VI ISA.");
120 const unsigned MaxInstBytesNum = (std::min)((size_t)8, Bytes_.size());
121 Bytes = Bytes_.slice(0, MaxInstBytesNum);
123 DecodeStatus Res = MCDisassembler::Fail;
125 // ToDo: better to switch encoding length using some bit predicate
126 // but it is unknown yet, so try all we can
128 // Try to decode DPP first to solve conflict with VOP1 and VOP2 encodings
129 if (Bytes.size() >= 8) {
130 const uint64_t QW = eatBytes<uint64_t>(Bytes);
131 Res = tryDecodeInst(DecoderTableDPP64, MI, QW, Address);
135 // Reinitialize Bytes as DPP64 could have eaten too much
136 Bytes = Bytes_.slice(0, MaxInstBytesNum);
138 // Try decode 32-bit instruction
139 if (Bytes.size() < 4) break;
140 const uint32_t DW = eatBytes<uint32_t>(Bytes);
141 Res = tryDecodeInst(DecoderTableVI32, MI, DW, Address);
144 Res = tryDecodeInst(DecoderTableAMDGPU32, MI, DW, Address);
147 if (Bytes.size() < 4) break;
148 const uint64_t QW = ((uint64_t)eatBytes<uint32_t>(Bytes) << 32) | DW;
149 Res = tryDecodeInst(DecoderTableVI64, MI, QW, Address);
152 Res = tryDecodeInst(DecoderTableAMDGPU64, MI, QW, Address);
155 Size = Res ? (MaxInstBytesNum - Bytes.size()) : 0;
159 const char* AMDGPUDisassembler::getRegClassName(unsigned RegClassID) const {
160 return getContext().getRegisterInfo()->
161 getRegClassName(&AMDGPUMCRegisterClasses[RegClassID]);
165 MCOperand AMDGPUDisassembler::errOperand(unsigned V,
166 const Twine& ErrMsg) const {
167 *CommentStream << "Error: " + ErrMsg;
169 // ToDo: add support for error operands to MCInst.h
170 // return MCOperand::createError(V);
175 MCOperand AMDGPUDisassembler::createRegOperand(unsigned int RegId) const {
176 return MCOperand::createReg(RegId);
180 MCOperand AMDGPUDisassembler::createRegOperand(unsigned RegClassID,
181 unsigned Val) const {
182 const auto& RegCl = AMDGPUMCRegisterClasses[RegClassID];
183 if (Val >= RegCl.getNumRegs())
184 return errOperand(Val, Twine(getRegClassName(RegClassID)) +
185 ": unknown register " + Twine(Val));
186 return createRegOperand(RegCl.getRegister(Val));
190 MCOperand AMDGPUDisassembler::createSRegOperand(unsigned SRegClassID,
191 unsigned Val) const {
192 // ToDo: SI/CI have 104 SGPRs, VI - 102
193 // Valery: here we accepting as much as we can, let assembler sort it out
195 switch (SRegClassID) {
196 case AMDGPU::SGPR_32RegClassID:
197 case AMDGPU::TTMP_32RegClassID:
199 case AMDGPU::SGPR_64RegClassID:
200 case AMDGPU::TTMP_64RegClassID:
203 case AMDGPU::SGPR_128RegClassID:
204 case AMDGPU::TTMP_128RegClassID:
205 // ToDo: unclear if s[100:104] is available on VI. Can we use VCC as SGPR in
207 case AMDGPU::SReg_256RegClassID:
208 // ToDo: unclear if s[96:104] is available on VI. Can we use VCC as SGPR in
210 case AMDGPU::SReg_512RegClassID:
213 // ToDo: unclear if s[88:104] is available on VI. Can we use VCC as SGPR in
219 if (Val % (1 << shift))
220 *CommentStream << "Warning: " << getRegClassName(SRegClassID)
221 << ": scalar reg isn't aligned " << Val;
222 return createRegOperand(SRegClassID, Val >> shift);
225 MCOperand AMDGPUDisassembler::decodeOperand_VS_32(unsigned Val) const {
226 return decodeSrcOp(OPW32, Val);
229 MCOperand AMDGPUDisassembler::decodeOperand_VS_64(unsigned Val) const {
230 return decodeSrcOp(OPW64, Val);
233 MCOperand AMDGPUDisassembler::decodeOperand_VGPR_32(unsigned Val) const {
234 return createRegOperand(AMDGPU::VGPR_32RegClassID, Val);
237 MCOperand AMDGPUDisassembler::decodeOperand_VReg_64(unsigned Val) const {
238 return createRegOperand(AMDGPU::VReg_64RegClassID, Val);
241 MCOperand AMDGPUDisassembler::decodeOperand_VReg_96(unsigned Val) const {
242 return createRegOperand(AMDGPU::VReg_96RegClassID, Val);
245 MCOperand AMDGPUDisassembler::decodeOperand_VReg_128(unsigned Val) const {
246 return createRegOperand(AMDGPU::VReg_128RegClassID, Val);
249 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32(unsigned Val) const {
250 // table-gen generated disassembler doesn't care about operand types
251 // leaving only registry class so SSrc_32 operand turns into SReg_32
252 // and therefore we accept immediates and literals here as well
253 return decodeSrcOp(OPW32, Val);
256 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32_XM0(unsigned Val) const {
257 // SReg_32_XM0 is SReg_32 without M0
258 return decodeOperand_SReg_32(Val);
261 MCOperand AMDGPUDisassembler::decodeOperand_SReg_64(unsigned Val) const {
262 // see decodeOperand_SReg_32 comment
263 return decodeSrcOp(OPW64, Val);
266 MCOperand AMDGPUDisassembler::decodeOperand_SReg_128(unsigned Val) const {
267 return decodeSrcOp(OPW128, Val);
270 MCOperand AMDGPUDisassembler::decodeOperand_SReg_256(unsigned Val) const {
271 return createSRegOperand(AMDGPU::SReg_256RegClassID, Val);
274 MCOperand AMDGPUDisassembler::decodeOperand_SReg_512(unsigned Val) const {
275 return createSRegOperand(AMDGPU::SReg_512RegClassID, Val);
279 MCOperand AMDGPUDisassembler::decodeLiteralConstant() const {
280 // For now all literal constants are supposed to be unsigned integer
281 // ToDo: deal with signed/unsigned 64-bit integer constants
282 // ToDo: deal with float/double constants
283 if (Bytes.size() < 4)
284 return errOperand(0, "cannot read literal, inst bytes left " +
285 Twine(Bytes.size()));
286 return MCOperand::createImm(eatBytes<uint32_t>(Bytes));
289 MCOperand AMDGPUDisassembler::decodeIntImmed(unsigned Imm) {
290 using namespace AMDGPU::EncValues;
291 assert(Imm >= INLINE_INTEGER_C_MIN && Imm <= INLINE_INTEGER_C_MAX);
292 return MCOperand::createImm((Imm <= INLINE_INTEGER_C_POSITIVE_MAX) ?
293 (static_cast<int64_t>(Imm) - INLINE_INTEGER_C_MIN) :
294 (INLINE_INTEGER_C_POSITIVE_MAX - static_cast<int64_t>(Imm)));
295 // Cast prevents negative overflow.
298 MCOperand AMDGPUDisassembler::decodeFPImmed(bool Is32, unsigned Imm) {
299 assert(Imm >= AMDGPU::EncValues::INLINE_FLOATING_C_MIN
300 && Imm <= AMDGPU::EncValues::INLINE_FLOATING_C_MAX);
301 // ToDo: case 248: 1/(2*PI) - is allowed only on VI
302 // ToDo: AMDGPUInstPrinter does not support 1/(2*PI). It consider 1/(2*PI) as
306 case 240: V = 0.5f; break;
307 case 241: V = -0.5f; break;
308 case 242: V = 1.0f; break;
309 case 243: V = -1.0f; break;
310 case 244: V = 2.0f; break;
311 case 245: V = -2.0f; break;
312 case 246: V = 4.0f; break;
313 case 247: V = -4.0f; break;
314 case 248: return MCOperand::createImm(Is32 ? // 1/(2*PI)
319 return MCOperand::createImm(Is32? FloatToBits(V) : DoubleToBits(V));
322 unsigned AMDGPUDisassembler::getVgprClassId(const OpWidthTy Width) const {
323 using namespace AMDGPU;
324 assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
327 case OPW32: return VGPR_32RegClassID;
328 case OPW64: return VReg_64RegClassID;
329 case OPW128: return VReg_128RegClassID;
333 unsigned AMDGPUDisassembler::getSgprClassId(const OpWidthTy Width) const {
334 using namespace AMDGPU;
335 assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
338 case OPW32: return SGPR_32RegClassID;
339 case OPW64: return SGPR_64RegClassID;
340 case OPW128: return SGPR_128RegClassID;
344 unsigned AMDGPUDisassembler::getTtmpClassId(const OpWidthTy Width) const {
345 using namespace AMDGPU;
346 assert(OPW_FIRST_ <= Width && Width < OPW_LAST_);
349 case OPW32: return TTMP_32RegClassID;
350 case OPW64: return TTMP_64RegClassID;
351 case OPW128: return TTMP_128RegClassID;
355 MCOperand AMDGPUDisassembler::decodeSrcOp(const OpWidthTy Width, unsigned Val) const {
356 using namespace AMDGPU::EncValues;
357 assert(Val < 512); // enum9
359 if (VGPR_MIN <= Val && Val <= VGPR_MAX) {
360 return createRegOperand(getVgprClassId(Width), Val - VGPR_MIN);
362 if (Val <= SGPR_MAX) {
363 assert(SGPR_MIN == 0); // "SGPR_MIN <= Val" is always true and causes compilation warning.
364 return createSRegOperand(getSgprClassId(Width), Val - SGPR_MIN);
366 if (TTMP_MIN <= Val && Val <= TTMP_MAX) {
367 return createSRegOperand(getTtmpClassId(Width), Val - TTMP_MIN);
370 assert(Width == OPW32 || Width == OPW64);
371 const bool Is32 = (Width == OPW32);
373 if (INLINE_INTEGER_C_MIN <= Val && Val <= INLINE_INTEGER_C_MAX)
374 return decodeIntImmed(Val);
376 if (INLINE_FLOATING_C_MIN <= Val && Val <= INLINE_FLOATING_C_MAX)
377 return decodeFPImmed(Is32, Val);
379 if (Val == LITERAL_CONST)
380 return decodeLiteralConstant();
382 return Is32 ? decodeSpecialReg32(Val) : decodeSpecialReg64(Val);
385 MCOperand AMDGPUDisassembler::decodeSpecialReg32(unsigned Val) const {
386 using namespace AMDGPU;
388 case 102: return createRegOperand(getMCReg(FLAT_SCR_LO, STI));
389 case 103: return createRegOperand(getMCReg(FLAT_SCR_HI, STI));
390 // ToDo: no support for xnack_mask_lo/_hi register
393 case 106: return createRegOperand(VCC_LO);
394 case 107: return createRegOperand(VCC_HI);
395 case 108: return createRegOperand(TBA_LO);
396 case 109: return createRegOperand(TBA_HI);
397 case 110: return createRegOperand(TMA_LO);
398 case 111: return createRegOperand(TMA_HI);
399 case 124: return createRegOperand(M0);
400 case 126: return createRegOperand(EXEC_LO);
401 case 127: return createRegOperand(EXEC_HI);
402 // ToDo: no support for vccz register
404 // ToDo: no support for execz register
406 case 253: return createRegOperand(SCC);
409 return errOperand(Val, "unknown operand encoding " + Twine(Val));
412 MCOperand AMDGPUDisassembler::decodeSpecialReg64(unsigned Val) const {
413 using namespace AMDGPU;
415 case 102: return createRegOperand(getMCReg(FLAT_SCR, STI));
416 case 106: return createRegOperand(VCC);
417 case 108: return createRegOperand(TBA);
418 case 110: return createRegOperand(TMA);
419 case 126: return createRegOperand(EXEC);
422 return errOperand(Val, "unknown operand encoding " + Twine(Val));
425 static MCDisassembler *createAMDGPUDisassembler(const Target &T,
426 const MCSubtargetInfo &STI,
428 return new AMDGPUDisassembler(STI, Ctx);
431 extern "C" void LLVMInitializeAMDGPUDisassembler() {
432 TargetRegistry::RegisterMCDisassembler(TheGCNTarget, createAMDGPUDisassembler);