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 "Utils/AMDGPUBaseInfo.h"
25 #include "llvm/MC/MCContext.h"
26 #include "llvm/MC/MCFixedLenDisassembler.h"
27 #include "llvm/MC/MCInst.h"
28 #include "llvm/MC/MCInstrDesc.h"
29 #include "llvm/MC/MCSubtargetInfo.h"
30 #include "llvm/Support/Endian.h"
31 #include "llvm/Support/Debug.h"
32 #include "llvm/Support/TargetRegistry.h"
37 #define DEBUG_TYPE "amdgpu-disassembler"
39 typedef llvm::MCDisassembler::DecodeStatus DecodeStatus;
42 inline static MCDisassembler::DecodeStatus
43 addOperand(MCInst &Inst, const MCOperand& Opnd) {
44 Inst.addOperand(Opnd);
45 return Opnd.isValid() ?
46 MCDisassembler::Success :
47 MCDisassembler::SoftFail;
50 #define DECODE_OPERAND2(RegClass, DecName) \
51 static DecodeStatus Decode##RegClass##RegisterClass(MCInst &Inst, \
54 const void *Decoder) { \
55 auto DAsm = static_cast<const AMDGPUDisassembler*>(Decoder); \
56 return addOperand(Inst, DAsm->decodeOperand_##DecName(Imm)); \
59 #define DECODE_OPERAND(RegClass) DECODE_OPERAND2(RegClass, RegClass)
61 DECODE_OPERAND(VGPR_32)
65 DECODE_OPERAND(VReg_64)
66 DECODE_OPERAND(VReg_96)
67 DECODE_OPERAND(VReg_128)
69 DECODE_OPERAND(SGPR_32)
70 DECODE_OPERAND(SReg_32)
71 DECODE_OPERAND(SReg_64)
72 DECODE_OPERAND(SReg_128)
73 DECODE_OPERAND(SReg_256)
74 DECODE_OPERAND(SReg_512)
76 #define GET_SUBTARGETINFO_ENUM
77 #include "AMDGPUGenSubtargetInfo.inc"
78 #undef GET_SUBTARGETINFO_ENUM
80 #include "AMDGPUGenDisassemblerTables.inc"
82 //===----------------------------------------------------------------------===//
84 //===----------------------------------------------------------------------===//
86 static inline uint32_t eatB32(ArrayRef<uint8_t>& Bytes) {
87 assert(Bytes.size() >= sizeof eatB32(Bytes));
88 const auto Res = support::endian::read32le(Bytes.data());
89 Bytes = Bytes.slice(sizeof Res);
93 DecodeStatus AMDGPUDisassembler::tryDecodeInst(const uint8_t* Table,
96 uint64_t Address) const {
97 assert(MI.getOpcode() == 0);
98 assert(MI.getNumOperands() == 0);
100 const auto SavedBytes = Bytes;
101 if (decodeInstruction(Table, TmpInst, Inst, Address, this, STI)) {
103 return MCDisassembler::Success;
106 return MCDisassembler::Fail;
109 DecodeStatus AMDGPUDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
110 ArrayRef<uint8_t> Bytes_,
113 raw_ostream &CS) const {
116 // ToDo: AMDGPUDisassembler supports only VI ISA.
117 assert(AMDGPU::isVI(STI) && "Can disassemble only VI ISA.");
119 const unsigned MaxInstBytesNum = (std::min)((size_t)8, Bytes_.size());
120 Bytes = Bytes_.slice(0, MaxInstBytesNum);
122 DecodeStatus Res = MCDisassembler::Fail;
124 // ToDo: better to switch encoding length using some bit predicate
125 // but it is unknown yet, so try all we can
126 if (Bytes.size() < 4) break;
127 const uint32_t DW = eatB32(Bytes);
128 Res = tryDecodeInst(DecoderTableVI32, MI, DW, Address);
131 Res = tryDecodeInst(DecoderTableAMDGPU32, MI, DW, Address);
134 if (Bytes.size() < 4) break;
135 const uint64_t QW = ((uint64_t)eatB32(Bytes) << 32) | DW;
136 Res = tryDecodeInst(DecoderTableVI64, MI, QW, Address);
139 Res = tryDecodeInst(DecoderTableAMDGPU64, MI, QW, Address);
142 Size = Res ? (MaxInstBytesNum - Bytes.size()) : 0;
146 const char* AMDGPUDisassembler::getRegClassName(unsigned RegClassID) const {
147 return getContext().getRegisterInfo()->
148 getRegClassName(&AMDGPUMCRegisterClasses[RegClassID]);
152 MCOperand AMDGPUDisassembler::errOperand(unsigned V,
153 const Twine& ErrMsg) const {
154 *CommentStream << "Error: " + ErrMsg;
156 // ToDo: add support for error operands to MCInst.h
157 // return MCOperand::createError(V);
162 MCOperand AMDGPUDisassembler::createRegOperand(unsigned int RegId) const {
163 return MCOperand::createReg(RegId);
167 MCOperand AMDGPUDisassembler::createRegOperand(unsigned RegClassID,
168 unsigned Val) const {
169 const auto& RegCl = AMDGPUMCRegisterClasses[RegClassID];
170 if (Val >= RegCl.getNumRegs())
171 return errOperand(Val, Twine(getRegClassName(RegClassID)) +
172 ": unknown register " + Twine(Val));
173 return createRegOperand(RegCl.getRegister(Val));
177 MCOperand AMDGPUDisassembler::createSRegOperand(unsigned SRegClassID,
178 unsigned Val) const {
179 // ToDo: SI/CI have 104 SGPRs, VI - 102
180 // Valery: here we accepting as much as we can, let assembler sort it out
182 switch (SRegClassID) {
183 case AMDGPU::SGPR_32RegClassID:
184 case AMDGPU::SReg_32RegClassID: break;
185 case AMDGPU::SGPR_64RegClassID:
186 case AMDGPU::SReg_64RegClassID: shift = 1; break;
187 case AMDGPU::SReg_128RegClassID:
188 // ToDo: unclear if s[100:104] is available on VI. Can we use VCC as SGPR in
190 case AMDGPU::SReg_256RegClassID:
191 // ToDo: unclear if s[96:104] is available on VI. Can we use VCC as SGPR in
193 case AMDGPU::SReg_512RegClassID: shift = 2; break;
194 // ToDo: unclear if s[88:104] is available on VI. Can we use VCC as SGPR in
196 default: assert(false); break;
198 if (Val % (1 << shift))
199 *CommentStream << "Warning: " << getRegClassName(SRegClassID)
200 << ": scalar reg isn't aligned " << Val;
201 return createRegOperand(SRegClassID, Val >> shift);
204 MCOperand AMDGPUDisassembler::decodeOperand_VS_32(unsigned Val) const {
205 return decodeSrcOp(OP32, Val);
208 MCOperand AMDGPUDisassembler::decodeOperand_VS_64(unsigned Val) const {
209 return decodeSrcOp(OP64, Val);
212 MCOperand AMDGPUDisassembler::decodeOperand_VGPR_32(unsigned Val) const {
213 return createRegOperand(AMDGPU::VGPR_32RegClassID, Val);
216 MCOperand AMDGPUDisassembler::decodeOperand_VReg_64(unsigned Val) const {
217 return createRegOperand(AMDGPU::VReg_64RegClassID, Val);
220 MCOperand AMDGPUDisassembler::decodeOperand_VReg_96(unsigned Val) const {
221 return createRegOperand(AMDGPU::VReg_96RegClassID, Val);
224 MCOperand AMDGPUDisassembler::decodeOperand_VReg_128(unsigned Val) const {
225 return createRegOperand(AMDGPU::VReg_128RegClassID, Val);
228 MCOperand AMDGPUDisassembler::decodeOperand_SGPR_32(unsigned Val) const {
229 return createSRegOperand(AMDGPU::SGPR_32RegClassID, Val);
232 MCOperand AMDGPUDisassembler::decodeOperand_SReg_32(unsigned Val) const {
233 // table-gen generated disassembler doesn't care about operand types
234 // leaving only registry class so SSrc_32 operand turns into SReg_32
235 // and therefore we accept immediates and literals here as well
236 return decodeSrcOp(OP32, Val);
239 MCOperand AMDGPUDisassembler::decodeOperand_SReg_64(unsigned Val) const {
240 // see decodeOperand_SReg_32 comment
241 return decodeSrcOp(OP64, Val);
244 MCOperand AMDGPUDisassembler::decodeOperand_SReg_128(unsigned Val) const {
245 return createSRegOperand(AMDGPU::SReg_128RegClassID, Val);
248 MCOperand AMDGPUDisassembler::decodeOperand_SReg_256(unsigned Val) const {
249 return createSRegOperand(AMDGPU::SReg_256RegClassID, Val);
252 MCOperand AMDGPUDisassembler::decodeOperand_SReg_512(unsigned Val) const {
253 return createSRegOperand(AMDGPU::SReg_512RegClassID, Val);
257 MCOperand AMDGPUDisassembler::decodeLiteralConstant() const {
258 // For now all literal constants are supposed to be unsigned integer
259 // ToDo: deal with signed/unsigned 64-bit integer constants
260 // ToDo: deal with float/double constants
261 if (Bytes.size() < 4)
262 return errOperand(0, "cannot read literal, inst bytes left " +
263 Twine(Bytes.size()));
264 return MCOperand::createImm(eatB32(Bytes));
267 MCOperand AMDGPUDisassembler::decodeIntImmed(unsigned Imm) {
268 assert(Imm >= 128 && Imm <= 208);
269 return MCOperand::createImm((Imm <= 192) ? (Imm - 128) : (192 - Imm));
272 MCOperand AMDGPUDisassembler::decodeFPImmed(bool Is32, unsigned Imm) {
273 assert(Imm >= 240 && Imm <= 248);
274 // ToDo: case 248: 1/(2*PI) - is allowed only on VI
275 // ToDo: AMDGPUInstPrinter does not support 1/(2*PI). It consider 1/(2*PI) as
279 case 240: V = 0.5f; break;
280 case 241: V = -0.5f; break;
281 case 242: V = 1.0f; break;
282 case 243: V = -1.0f; break;
283 case 244: V = 2.0f; break;
284 case 245: V = -2.0f; break;
285 case 246: V = 4.0f; break;
286 case 247: V = -4.0f; break;
287 case 248: return MCOperand::createImm(Is32 ? // 1/(2*PI)
292 return MCOperand::createImm(Is32? FloatToBits(V) : DoubleToBits(V));
295 MCOperand AMDGPUDisassembler::decodeSrcOp(bool Is32, unsigned Val) const {
296 using namespace AMDGPU;
297 assert(Val < 512); // enum9
300 return createRegOperand(Is32 ? VGPR_32RegClassID : VReg_64RegClassID,
303 return createSRegOperand(Is32 ? SGPR_32RegClassID : SGPR_64RegClassID,
306 if (Val >= 128 && Val <= 208)
307 return decodeIntImmed(Val);
309 if (Val >= 240 && Val <= 248)
310 return decodeFPImmed(Is32, Val);
313 return decodeLiteralConstant();
315 return Is32 ? decodeSpecialReg32(Val) : decodeSpecialReg64(Val);
318 MCOperand AMDGPUDisassembler::decodeSpecialReg32(unsigned Val) const {
319 using namespace AMDGPU;
321 case 102: return createRegOperand(getMCReg(FLAT_SCR_LO, STI));
322 case 103: return createRegOperand(getMCReg(FLAT_SCR_HI, STI));
323 // ToDo: no support for xnack_mask_lo/_hi register
326 case 106: return createRegOperand(VCC_LO);
327 case 107: return createRegOperand(VCC_HI);
328 // ToDo: no support for tba_lo/_hi register
331 // ToDo: no support for tma_lo/_hi register
334 // ToDo: no support for ttmp[0:11] register
347 case 124: return createRegOperand(M0);
348 case 126: return createRegOperand(EXEC_LO);
349 case 127: return createRegOperand(EXEC_HI);
350 // ToDo: no support for vccz register
352 // ToDo: no support for execz register
354 case 253: return createRegOperand(SCC);
357 return errOperand(Val, "unknown operand encoding " + Twine(Val));
360 MCOperand AMDGPUDisassembler::decodeSpecialReg64(unsigned Val) const {
361 using namespace AMDGPU;
363 case 102: return createRegOperand(getMCReg(FLAT_SCR, STI));
364 case 106: return createRegOperand(VCC);
365 case 126: return createRegOperand(EXEC);
368 return errOperand(Val, "unknown operand encoding " + Twine(Val));
371 static MCDisassembler *createAMDGPUDisassembler(const Target &T,
372 const MCSubtargetInfo &STI,
374 return new AMDGPUDisassembler(STI, Ctx);
377 extern "C" void LLVMInitializeAMDGPUDisassembler() {
378 TargetRegistry::RegisterMCDisassembler(TheGCNTarget, createAMDGPUDisassembler);