1 //===-- RISCVMCCodeEmitter.cpp - Convert RISC-V code to machine code ------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements the RISCVMCCodeEmitter class. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "MCTargetDesc/RISCVBaseInfo.h" 14 #include "MCTargetDesc/RISCVFixupKinds.h" 15 #include "MCTargetDesc/RISCVMCExpr.h" 16 #include "MCTargetDesc/RISCVMCTargetDesc.h" 17 #include "llvm/ADT/Statistic.h" 18 #include "llvm/MC/MCAsmInfo.h" 19 #include "llvm/MC/MCCodeEmitter.h" 20 #include "llvm/MC/MCContext.h" 21 #include "llvm/MC/MCExpr.h" 22 #include "llvm/MC/MCInst.h" 23 #include "llvm/MC/MCInstBuilder.h" 24 #include "llvm/MC/MCInstrInfo.h" 25 #include "llvm/MC/MCRegisterInfo.h" 26 #include "llvm/MC/MCSubtargetInfo.h" 27 #include "llvm/MC/MCSymbol.h" 28 #include "llvm/Support/Casting.h" 29 #include "llvm/Support/EndianStream.h" 30 #include "llvm/Support/raw_ostream.h" 31 32 using namespace llvm; 33 34 #define DEBUG_TYPE "mccodeemitter" 35 36 STATISTIC(MCNumEmitted, "Number of MC instructions emitted"); 37 STATISTIC(MCNumFixups, "Number of MC fixups created"); 38 39 namespace { 40 class RISCVMCCodeEmitter : public MCCodeEmitter { 41 RISCVMCCodeEmitter(const RISCVMCCodeEmitter &) = delete; 42 void operator=(const RISCVMCCodeEmitter &) = delete; 43 MCContext &Ctx; 44 MCInstrInfo const &MCII; 45 46 public: 47 RISCVMCCodeEmitter(MCContext &ctx, MCInstrInfo const &MCII) 48 : Ctx(ctx), MCII(MCII) {} 49 50 ~RISCVMCCodeEmitter() override = default; 51 52 void encodeInstruction(const MCInst &MI, SmallVectorImpl<char> &CB, 53 SmallVectorImpl<MCFixup> &Fixups, 54 const MCSubtargetInfo &STI) const override; 55 56 void expandFunctionCall(const MCInst &MI, SmallVectorImpl<char> &CB, 57 SmallVectorImpl<MCFixup> &Fixups, 58 const MCSubtargetInfo &STI) const; 59 60 void expandTLSDESCCall(const MCInst &MI, SmallVectorImpl<char> &CB, 61 SmallVectorImpl<MCFixup> &Fixups, 62 const MCSubtargetInfo &STI) const; 63 64 void expandAddTPRel(const MCInst &MI, SmallVectorImpl<char> &CB, 65 SmallVectorImpl<MCFixup> &Fixups, 66 const MCSubtargetInfo &STI) const; 67 68 void expandLongCondBr(const MCInst &MI, SmallVectorImpl<char> &CB, 69 SmallVectorImpl<MCFixup> &Fixups, 70 const MCSubtargetInfo &STI) const; 71 72 /// TableGen'erated function for getting the binary encoding for an 73 /// instruction. 74 uint64_t getBinaryCodeForInstr(const MCInst &MI, 75 SmallVectorImpl<MCFixup> &Fixups, 76 const MCSubtargetInfo &STI) const; 77 78 /// Return binary encoding of operand. If the machine operand requires 79 /// relocation, record the relocation and return zero. 80 unsigned getMachineOpValue(const MCInst &MI, const MCOperand &MO, 81 SmallVectorImpl<MCFixup> &Fixups, 82 const MCSubtargetInfo &STI) const; 83 84 unsigned getImmOpValueAsr1(const MCInst &MI, unsigned OpNo, 85 SmallVectorImpl<MCFixup> &Fixups, 86 const MCSubtargetInfo &STI) const; 87 88 unsigned getImmOpValue(const MCInst &MI, unsigned OpNo, 89 SmallVectorImpl<MCFixup> &Fixups, 90 const MCSubtargetInfo &STI) const; 91 92 unsigned getVMaskReg(const MCInst &MI, unsigned OpNo, 93 SmallVectorImpl<MCFixup> &Fixups, 94 const MCSubtargetInfo &STI) const; 95 96 unsigned getRlistOpValue(const MCInst &MI, unsigned OpNo, 97 SmallVectorImpl<MCFixup> &Fixups, 98 const MCSubtargetInfo &STI) const; 99 100 unsigned getRegReg(const MCInst &MI, unsigned OpNo, 101 SmallVectorImpl<MCFixup> &Fixups, 102 const MCSubtargetInfo &STI) const; 103 }; 104 } // end anonymous namespace 105 106 MCCodeEmitter *llvm::createRISCVMCCodeEmitter(const MCInstrInfo &MCII, 107 MCContext &Ctx) { 108 return new RISCVMCCodeEmitter(Ctx, MCII); 109 } 110 111 // Expand PseudoCALL(Reg), PseudoTAIL and PseudoJump to AUIPC and JALR with 112 // relocation types. We expand those pseudo-instructions while encoding them, 113 // meaning AUIPC and JALR won't go through RISC-V MC to MC compressed 114 // instruction transformation. This is acceptable because AUIPC has no 16-bit 115 // form and C_JALR has no immediate operand field. We let linker relaxation 116 // deal with it. When linker relaxation is enabled, AUIPC and JALR have a 117 // chance to relax to JAL. 118 // If the C extension is enabled, JAL has a chance relax to C_JAL. 119 void RISCVMCCodeEmitter::expandFunctionCall(const MCInst &MI, 120 SmallVectorImpl<char> &CB, 121 SmallVectorImpl<MCFixup> &Fixups, 122 const MCSubtargetInfo &STI) const { 123 MCInst TmpInst; 124 MCOperand Func; 125 MCRegister Ra; 126 if (MI.getOpcode() == RISCV::PseudoTAIL) { 127 Func = MI.getOperand(0); 128 Ra = RISCV::X6; 129 // For Zicfilp, PseudoTAIL should be expanded to a software guarded branch. 130 // It means to use t2(x7) as rs1 of JALR to expand PseudoTAIL. 131 if (STI.hasFeature(RISCV::FeatureStdExtZicfilp)) 132 Ra = RISCV::X7; 133 } else if (MI.getOpcode() == RISCV::PseudoCALLReg) { 134 Func = MI.getOperand(1); 135 Ra = MI.getOperand(0).getReg(); 136 } else if (MI.getOpcode() == RISCV::PseudoCALL) { 137 Func = MI.getOperand(0); 138 Ra = RISCV::X1; 139 } else if (MI.getOpcode() == RISCV::PseudoJump) { 140 Func = MI.getOperand(1); 141 Ra = MI.getOperand(0).getReg(); 142 } 143 uint32_t Binary; 144 145 assert(Func.isExpr() && "Expected expression"); 146 147 const MCExpr *CallExpr = Func.getExpr(); 148 149 // Emit AUIPC Ra, Func with R_RISCV_CALL relocation type. 150 TmpInst = MCInstBuilder(RISCV::AUIPC).addReg(Ra).addExpr(CallExpr); 151 Binary = getBinaryCodeForInstr(TmpInst, Fixups, STI); 152 support::endian::write(CB, Binary, llvm::endianness::little); 153 154 if (MI.getOpcode() == RISCV::PseudoTAIL || 155 MI.getOpcode() == RISCV::PseudoJump) 156 // Emit JALR X0, Ra, 0 157 TmpInst = MCInstBuilder(RISCV::JALR).addReg(RISCV::X0).addReg(Ra).addImm(0); 158 else 159 // Emit JALR Ra, Ra, 0 160 TmpInst = MCInstBuilder(RISCV::JALR).addReg(Ra).addReg(Ra).addImm(0); 161 Binary = getBinaryCodeForInstr(TmpInst, Fixups, STI); 162 support::endian::write(CB, Binary, llvm::endianness::little); 163 } 164 165 void RISCVMCCodeEmitter::expandTLSDESCCall(const MCInst &MI, 166 SmallVectorImpl<char> &CB, 167 SmallVectorImpl<MCFixup> &Fixups, 168 const MCSubtargetInfo &STI) const { 169 MCOperand SrcSymbol = MI.getOperand(3); 170 assert(SrcSymbol.isExpr() && 171 "Expected expression as first input to TLSDESCCALL"); 172 const RISCVMCExpr *Expr = dyn_cast<RISCVMCExpr>(SrcSymbol.getExpr()); 173 MCRegister Link = MI.getOperand(0).getReg(); 174 MCRegister Dest = MI.getOperand(1).getReg(); 175 MCRegister Imm = MI.getOperand(2).getImm(); 176 Fixups.push_back(MCFixup::create( 177 0, Expr, MCFixupKind(RISCV::fixup_riscv_tlsdesc_call), MI.getLoc())); 178 MCInst Call = 179 MCInstBuilder(RISCV::JALR).addReg(Link).addReg(Dest).addImm(Imm); 180 181 uint32_t Binary = getBinaryCodeForInstr(Call, Fixups, STI); 182 support::endian::write(CB, Binary, llvm::endianness::little); 183 } 184 185 // Expand PseudoAddTPRel to a simple ADD with the correct relocation. 186 void RISCVMCCodeEmitter::expandAddTPRel(const MCInst &MI, 187 SmallVectorImpl<char> &CB, 188 SmallVectorImpl<MCFixup> &Fixups, 189 const MCSubtargetInfo &STI) const { 190 MCOperand DestReg = MI.getOperand(0); 191 MCOperand SrcReg = MI.getOperand(1); 192 MCOperand TPReg = MI.getOperand(2); 193 assert(TPReg.isReg() && TPReg.getReg() == RISCV::X4 && 194 "Expected thread pointer as second input to TP-relative add"); 195 196 MCOperand SrcSymbol = MI.getOperand(3); 197 assert(SrcSymbol.isExpr() && 198 "Expected expression as third input to TP-relative add"); 199 200 const RISCVMCExpr *Expr = dyn_cast<RISCVMCExpr>(SrcSymbol.getExpr()); 201 assert(Expr && Expr->getKind() == RISCVMCExpr::VK_RISCV_TPREL_ADD && 202 "Expected tprel_add relocation on TP-relative symbol"); 203 204 // Emit the correct tprel_add relocation for the symbol. 205 Fixups.push_back(MCFixup::create( 206 0, Expr, MCFixupKind(RISCV::fixup_riscv_tprel_add), MI.getLoc())); 207 208 // Emit fixup_riscv_relax for tprel_add where the relax feature is enabled. 209 if (STI.hasFeature(RISCV::FeatureRelax)) { 210 const MCConstantExpr *Dummy = MCConstantExpr::create(0, Ctx); 211 Fixups.push_back(MCFixup::create( 212 0, Dummy, MCFixupKind(RISCV::fixup_riscv_relax), MI.getLoc())); 213 } 214 215 // Emit a normal ADD instruction with the given operands. 216 MCInst TmpInst = MCInstBuilder(RISCV::ADD) 217 .addOperand(DestReg) 218 .addOperand(SrcReg) 219 .addOperand(TPReg); 220 uint32_t Binary = getBinaryCodeForInstr(TmpInst, Fixups, STI); 221 support::endian::write(CB, Binary, llvm::endianness::little); 222 } 223 224 static unsigned getInvertedBranchOp(unsigned BrOp) { 225 switch (BrOp) { 226 default: 227 llvm_unreachable("Unexpected branch opcode!"); 228 case RISCV::PseudoLongBEQ: 229 return RISCV::BNE; 230 case RISCV::PseudoLongBNE: 231 return RISCV::BEQ; 232 case RISCV::PseudoLongBLT: 233 return RISCV::BGE; 234 case RISCV::PseudoLongBGE: 235 return RISCV::BLT; 236 case RISCV::PseudoLongBLTU: 237 return RISCV::BGEU; 238 case RISCV::PseudoLongBGEU: 239 return RISCV::BLTU; 240 } 241 } 242 243 // Expand PseudoLongBxx to an inverted conditional branch and an unconditional 244 // jump. 245 void RISCVMCCodeEmitter::expandLongCondBr(const MCInst &MI, 246 SmallVectorImpl<char> &CB, 247 SmallVectorImpl<MCFixup> &Fixups, 248 const MCSubtargetInfo &STI) const { 249 MCRegister SrcReg1 = MI.getOperand(0).getReg(); 250 MCRegister SrcReg2 = MI.getOperand(1).getReg(); 251 MCOperand SrcSymbol = MI.getOperand(2); 252 unsigned Opcode = MI.getOpcode(); 253 bool IsEqTest = 254 Opcode == RISCV::PseudoLongBNE || Opcode == RISCV::PseudoLongBEQ; 255 256 bool UseCompressedBr = false; 257 if (IsEqTest && (STI.hasFeature(RISCV::FeatureStdExtC) || 258 STI.hasFeature(RISCV::FeatureStdExtZca))) { 259 if (RISCV::X8 <= SrcReg1.id() && SrcReg1.id() <= RISCV::X15 && 260 SrcReg2.id() == RISCV::X0) { 261 UseCompressedBr = true; 262 } else if (RISCV::X8 <= SrcReg2.id() && SrcReg2.id() <= RISCV::X15 && 263 SrcReg1.id() == RISCV::X0) { 264 std::swap(SrcReg1, SrcReg2); 265 UseCompressedBr = true; 266 } 267 } 268 269 uint32_t Offset; 270 if (UseCompressedBr) { 271 unsigned InvOpc = 272 Opcode == RISCV::PseudoLongBNE ? RISCV::C_BEQZ : RISCV::C_BNEZ; 273 MCInst TmpInst = MCInstBuilder(InvOpc).addReg(SrcReg1).addImm(6); 274 uint16_t Binary = getBinaryCodeForInstr(TmpInst, Fixups, STI); 275 support::endian::write<uint16_t>(CB, Binary, llvm::endianness::little); 276 Offset = 2; 277 } else { 278 unsigned InvOpc = getInvertedBranchOp(Opcode); 279 MCInst TmpInst = 280 MCInstBuilder(InvOpc).addReg(SrcReg1).addReg(SrcReg2).addImm(8); 281 uint32_t Binary = getBinaryCodeForInstr(TmpInst, Fixups, STI); 282 support::endian::write(CB, Binary, llvm::endianness::little); 283 Offset = 4; 284 } 285 286 // Emit an unconditional jump to the destination. 287 MCInst TmpInst = 288 MCInstBuilder(RISCV::JAL).addReg(RISCV::X0).addOperand(SrcSymbol); 289 uint32_t Binary = getBinaryCodeForInstr(TmpInst, Fixups, STI); 290 support::endian::write(CB, Binary, llvm::endianness::little); 291 292 Fixups.clear(); 293 if (SrcSymbol.isExpr()) { 294 Fixups.push_back(MCFixup::create(Offset, SrcSymbol.getExpr(), 295 MCFixupKind(RISCV::fixup_riscv_jal), 296 MI.getLoc())); 297 } 298 } 299 300 void RISCVMCCodeEmitter::encodeInstruction(const MCInst &MI, 301 SmallVectorImpl<char> &CB, 302 SmallVectorImpl<MCFixup> &Fixups, 303 const MCSubtargetInfo &STI) const { 304 const MCInstrDesc &Desc = MCII.get(MI.getOpcode()); 305 // Get byte count of instruction. 306 unsigned Size = Desc.getSize(); 307 308 // RISCVInstrInfo::getInstSizeInBytes expects that the total size of the 309 // expanded instructions for each pseudo is correct in the Size field of the 310 // tablegen definition for the pseudo. 311 switch (MI.getOpcode()) { 312 default: 313 break; 314 case RISCV::PseudoCALLReg: 315 case RISCV::PseudoCALL: 316 case RISCV::PseudoTAIL: 317 case RISCV::PseudoJump: 318 expandFunctionCall(MI, CB, Fixups, STI); 319 MCNumEmitted += 2; 320 return; 321 case RISCV::PseudoAddTPRel: 322 expandAddTPRel(MI, CB, Fixups, STI); 323 MCNumEmitted += 1; 324 return; 325 case RISCV::PseudoLongBEQ: 326 case RISCV::PseudoLongBNE: 327 case RISCV::PseudoLongBLT: 328 case RISCV::PseudoLongBGE: 329 case RISCV::PseudoLongBLTU: 330 case RISCV::PseudoLongBGEU: 331 expandLongCondBr(MI, CB, Fixups, STI); 332 MCNumEmitted += 2; 333 return; 334 case RISCV::PseudoTLSDESCCall: 335 expandTLSDESCCall(MI, CB, Fixups, STI); 336 MCNumEmitted += 1; 337 return; 338 } 339 340 switch (Size) { 341 default: 342 llvm_unreachable("Unhandled encodeInstruction length!"); 343 case 2: { 344 uint16_t Bits = getBinaryCodeForInstr(MI, Fixups, STI); 345 support::endian::write<uint16_t>(CB, Bits, llvm::endianness::little); 346 break; 347 } 348 case 4: { 349 uint32_t Bits = getBinaryCodeForInstr(MI, Fixups, STI); 350 support::endian::write(CB, Bits, llvm::endianness::little); 351 break; 352 } 353 } 354 355 ++MCNumEmitted; // Keep track of the # of mi's emitted. 356 } 357 358 unsigned 359 RISCVMCCodeEmitter::getMachineOpValue(const MCInst &MI, const MCOperand &MO, 360 SmallVectorImpl<MCFixup> &Fixups, 361 const MCSubtargetInfo &STI) const { 362 363 if (MO.isReg()) 364 return Ctx.getRegisterInfo()->getEncodingValue(MO.getReg()); 365 366 if (MO.isImm()) 367 return static_cast<unsigned>(MO.getImm()); 368 369 llvm_unreachable("Unhandled expression!"); 370 return 0; 371 } 372 373 unsigned 374 RISCVMCCodeEmitter::getImmOpValueAsr1(const MCInst &MI, unsigned OpNo, 375 SmallVectorImpl<MCFixup> &Fixups, 376 const MCSubtargetInfo &STI) const { 377 const MCOperand &MO = MI.getOperand(OpNo); 378 379 if (MO.isImm()) { 380 unsigned Res = MO.getImm(); 381 assert((Res & 1) == 0 && "LSB is non-zero"); 382 return Res >> 1; 383 } 384 385 return getImmOpValue(MI, OpNo, Fixups, STI); 386 } 387 388 unsigned RISCVMCCodeEmitter::getImmOpValue(const MCInst &MI, unsigned OpNo, 389 SmallVectorImpl<MCFixup> &Fixups, 390 const MCSubtargetInfo &STI) const { 391 bool EnableRelax = STI.hasFeature(RISCV::FeatureRelax); 392 const MCOperand &MO = MI.getOperand(OpNo); 393 394 MCInstrDesc const &Desc = MCII.get(MI.getOpcode()); 395 unsigned MIFrm = RISCVII::getFormat(Desc.TSFlags); 396 397 // If the destination is an immediate, there is nothing to do. 398 if (MO.isImm()) 399 return MO.getImm(); 400 401 assert(MO.isExpr() && 402 "getImmOpValue expects only expressions or immediates"); 403 const MCExpr *Expr = MO.getExpr(); 404 MCExpr::ExprKind Kind = Expr->getKind(); 405 RISCV::Fixups FixupKind = RISCV::fixup_riscv_invalid; 406 bool RelaxCandidate = false; 407 if (Kind == MCExpr::Target) { 408 const RISCVMCExpr *RVExpr = cast<RISCVMCExpr>(Expr); 409 410 switch (RVExpr->getKind()) { 411 case RISCVMCExpr::VK_RISCV_None: 412 case RISCVMCExpr::VK_RISCV_Invalid: 413 case RISCVMCExpr::VK_RISCV_32_PCREL: 414 llvm_unreachable("Unhandled fixup kind!"); 415 case RISCVMCExpr::VK_RISCV_TPREL_ADD: 416 // tprel_add is only used to indicate that a relocation should be emitted 417 // for an add instruction used in TP-relative addressing. It should not be 418 // expanded as if representing an actual instruction operand and so to 419 // encounter it here is an error. 420 llvm_unreachable( 421 "VK_RISCV_TPREL_ADD should not represent an instruction operand"); 422 case RISCVMCExpr::VK_RISCV_LO: 423 if (MIFrm == RISCVII::InstFormatI) 424 FixupKind = RISCV::fixup_riscv_lo12_i; 425 else if (MIFrm == RISCVII::InstFormatS) 426 FixupKind = RISCV::fixup_riscv_lo12_s; 427 else 428 llvm_unreachable("VK_RISCV_LO used with unexpected instruction format"); 429 RelaxCandidate = true; 430 break; 431 case RISCVMCExpr::VK_RISCV_HI: 432 FixupKind = RISCV::fixup_riscv_hi20; 433 RelaxCandidate = true; 434 break; 435 case RISCVMCExpr::VK_RISCV_PCREL_LO: 436 if (MIFrm == RISCVII::InstFormatI) 437 FixupKind = RISCV::fixup_riscv_pcrel_lo12_i; 438 else if (MIFrm == RISCVII::InstFormatS) 439 FixupKind = RISCV::fixup_riscv_pcrel_lo12_s; 440 else 441 llvm_unreachable( 442 "VK_RISCV_PCREL_LO used with unexpected instruction format"); 443 RelaxCandidate = true; 444 break; 445 case RISCVMCExpr::VK_RISCV_PCREL_HI: 446 FixupKind = RISCV::fixup_riscv_pcrel_hi20; 447 RelaxCandidate = true; 448 break; 449 case RISCVMCExpr::VK_RISCV_GOT_HI: 450 FixupKind = RISCV::fixup_riscv_got_hi20; 451 break; 452 case RISCVMCExpr::VK_RISCV_TPREL_LO: 453 if (MIFrm == RISCVII::InstFormatI) 454 FixupKind = RISCV::fixup_riscv_tprel_lo12_i; 455 else if (MIFrm == RISCVII::InstFormatS) 456 FixupKind = RISCV::fixup_riscv_tprel_lo12_s; 457 else 458 llvm_unreachable( 459 "VK_RISCV_TPREL_LO used with unexpected instruction format"); 460 RelaxCandidate = true; 461 break; 462 case RISCVMCExpr::VK_RISCV_TPREL_HI: 463 FixupKind = RISCV::fixup_riscv_tprel_hi20; 464 RelaxCandidate = true; 465 break; 466 case RISCVMCExpr::VK_RISCV_TLS_GOT_HI: 467 FixupKind = RISCV::fixup_riscv_tls_got_hi20; 468 break; 469 case RISCVMCExpr::VK_RISCV_TLS_GD_HI: 470 FixupKind = RISCV::fixup_riscv_tls_gd_hi20; 471 break; 472 case RISCVMCExpr::VK_RISCV_CALL: 473 FixupKind = RISCV::fixup_riscv_call; 474 RelaxCandidate = true; 475 break; 476 case RISCVMCExpr::VK_RISCV_CALL_PLT: 477 FixupKind = RISCV::fixup_riscv_call_plt; 478 RelaxCandidate = true; 479 break; 480 case RISCVMCExpr::VK_RISCV_TLSDESC_HI: 481 FixupKind = RISCV::fixup_riscv_tlsdesc_hi20; 482 break; 483 case RISCVMCExpr::VK_RISCV_TLSDESC_LOAD_LO: 484 FixupKind = RISCV::fixup_riscv_tlsdesc_load_lo12; 485 break; 486 case RISCVMCExpr::VK_RISCV_TLSDESC_ADD_LO: 487 FixupKind = RISCV::fixup_riscv_tlsdesc_add_lo12; 488 break; 489 case RISCVMCExpr::VK_RISCV_TLSDESC_CALL: 490 FixupKind = RISCV::fixup_riscv_tlsdesc_call; 491 break; 492 } 493 } else if ((Kind == MCExpr::SymbolRef && 494 cast<MCSymbolRefExpr>(Expr)->getKind() == 495 MCSymbolRefExpr::VK_None) || 496 Kind == MCExpr::Binary) { 497 // FIXME: Sub kind binary exprs have chance of underflow. 498 if (MIFrm == RISCVII::InstFormatJ) { 499 FixupKind = RISCV::fixup_riscv_jal; 500 } else if (MIFrm == RISCVII::InstFormatB) { 501 FixupKind = RISCV::fixup_riscv_branch; 502 } else if (MIFrm == RISCVII::InstFormatCJ) { 503 FixupKind = RISCV::fixup_riscv_rvc_jump; 504 } else if (MIFrm == RISCVII::InstFormatCB) { 505 FixupKind = RISCV::fixup_riscv_rvc_branch; 506 } else if (MIFrm == RISCVII::InstFormatI) { 507 FixupKind = RISCV::fixup_riscv_12_i; 508 } 509 } 510 511 assert(FixupKind != RISCV::fixup_riscv_invalid && "Unhandled expression!"); 512 513 Fixups.push_back( 514 MCFixup::create(0, Expr, MCFixupKind(FixupKind), MI.getLoc())); 515 ++MCNumFixups; 516 517 // Ensure an R_RISCV_RELAX relocation will be emitted if linker relaxation is 518 // enabled and the current fixup will result in a relocation that may be 519 // relaxed. 520 if (EnableRelax && RelaxCandidate) { 521 const MCConstantExpr *Dummy = MCConstantExpr::create(0, Ctx); 522 Fixups.push_back( 523 MCFixup::create(0, Dummy, MCFixupKind(RISCV::fixup_riscv_relax), 524 MI.getLoc())); 525 ++MCNumFixups; 526 } 527 528 return 0; 529 } 530 531 unsigned RISCVMCCodeEmitter::getVMaskReg(const MCInst &MI, unsigned OpNo, 532 SmallVectorImpl<MCFixup> &Fixups, 533 const MCSubtargetInfo &STI) const { 534 MCOperand MO = MI.getOperand(OpNo); 535 assert(MO.isReg() && "Expected a register."); 536 537 switch (MO.getReg()) { 538 default: 539 llvm_unreachable("Invalid mask register."); 540 case RISCV::V0: 541 return 0; 542 case RISCV::NoRegister: 543 return 1; 544 } 545 } 546 547 unsigned RISCVMCCodeEmitter::getRlistOpValue(const MCInst &MI, unsigned OpNo, 548 SmallVectorImpl<MCFixup> &Fixups, 549 const MCSubtargetInfo &STI) const { 550 const MCOperand &MO = MI.getOperand(OpNo); 551 assert(MO.isImm() && "Rlist operand must be immediate"); 552 auto Imm = MO.getImm(); 553 assert(Imm >= 4 && "EABI is currently not implemented"); 554 return Imm; 555 } 556 557 unsigned RISCVMCCodeEmitter::getRegReg(const MCInst &MI, unsigned OpNo, 558 SmallVectorImpl<MCFixup> &Fixups, 559 const MCSubtargetInfo &STI) const { 560 const MCOperand &MO = MI.getOperand(OpNo); 561 const MCOperand &MO1 = MI.getOperand(OpNo + 1); 562 assert(MO.isReg() && MO1.isReg() && "Expected registers."); 563 564 unsigned Op = Ctx.getRegisterInfo()->getEncodingValue(MO.getReg()); 565 unsigned Op1 = Ctx.getRegisterInfo()->getEncodingValue(MO1.getReg()); 566 567 return Op | Op1 << 5; 568 } 569 570 #include "RISCVGenMCCodeEmitter.inc" 571