llvm/lib/Target/RISCV/MCTargetDesc/RISCVBaseInfo.h

   1 //===-- RISCVBaseInfo.h - Top level definitions for RISC-V MC ---*- C++ -*-===//
   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 contains small standalone enum definitions for the RISC-V target
  10 // useful for the compiler back-end and the MC libraries.
  11 //
  12 //===----------------------------------------------------------------------===//
  13 #ifndef LLVM_LIB_TARGET_RISCV_MCTARGETDESC_RISCVBASEINFO_H
  14 #define LLVM_LIB_TARGET_RISCV_MCTARGETDESC_RISCVBASEINFO_H
  15
  16 #include "MCTargetDesc/RISCVMCTargetDesc.h"
  17 #include "llvm/ADT/APFloat.h"
  18 #include "llvm/ADT/APInt.h"
  19 #include "llvm/ADT/StringRef.h"
  20 #include "llvm/ADT/StringSwitch.h"
  21 #include "llvm/MC/MCInstrDesc.h"
  22 #include "llvm/Support/RISCVISAInfo.h"
  23 #include "llvm/TargetParser/SubtargetFeature.h"
  24
  25 namespace llvm {
  26
  27 // RISCVII - This namespace holds all of the target specific flags that
  28 // instruction info tracks. All definitions must match RISCVInstrFormats.td.
  29 namespace RISCVII {
  30 enum {
  31   InstFormatPseudo = 0,
  32   InstFormatR = 1,
  33   InstFormatR4 = 2,
  34   InstFormatI = 3,
  35   InstFormatS = 4,
  36   InstFormatB = 5,
  37   InstFormatU = 6,
  38   InstFormatJ = 7,
  39   InstFormatCR = 8,
  40   InstFormatCI = 9,
  41   InstFormatCSS = 10,
  42   InstFormatCIW = 11,
  43   InstFormatCL = 12,
  44   InstFormatCS = 13,
  45   InstFormatCA = 14,
  46   InstFormatCB = 15,
  47   InstFormatCJ = 16,
  48   InstFormatCU = 17,
  49   InstFormatCLB = 18,
  50   InstFormatCLH = 19,
  51   InstFormatCSB = 20,
  52   InstFormatCSH = 21,
  53   InstFormatOther = 22,
  54
  55   InstFormatMask = 31,
  56   InstFormatShift = 0,
  57
  58   ConstraintShift = InstFormatShift + 5,
  59   VS2Constraint = 0b001 << ConstraintShift,
  60   VS1Constraint = 0b010 << ConstraintShift,
  61   VMConstraint = 0b100 << ConstraintShift,
  62   ConstraintMask = 0b111 << ConstraintShift,
  63
  64   VLMulShift = ConstraintShift + 3,
  65   VLMulMask = 0b111 << VLMulShift,
  66
  67   // Force a tail agnostic policy even this instruction has a tied destination.
  68   ForceTailAgnosticShift = VLMulShift + 3,
  69   ForceTailAgnosticMask = 1 << ForceTailAgnosticShift,
  70
  71   // Is this a _TIED vector pseudo instruction. For these instructions we
  72   // shouldn't skip the tied operand when converting to MC instructions.
  73   IsTiedPseudoShift = ForceTailAgnosticShift + 1,
  74   IsTiedPseudoMask = 1 << IsTiedPseudoShift,
  75
  76   // Does this instruction have a SEW operand. It will be the last explicit
  77   // operand unless there is a vector policy operand. Used by RVV Pseudos.
  78   HasSEWOpShift = IsTiedPseudoShift + 1,
  79   HasSEWOpMask = 1 << HasSEWOpShift,
  80
  81   // Does this instruction have a VL operand. It will be the second to last
  82   // explicit operand unless there is a vector policy operand. Used by RVV
  83   // Pseudos.
  84   HasVLOpShift = HasSEWOpShift + 1,
  85   HasVLOpMask = 1 << HasVLOpShift,
  86
  87   // Does this instruction have a vector policy operand. It will be the last
  88   // explicit operand. Used by RVV Pseudos.
  89   HasVecPolicyOpShift = HasVLOpShift + 1,
  90   HasVecPolicyOpMask = 1 << HasVecPolicyOpShift,
  91
  92   // Is this instruction a vector widening reduction instruction. Used by RVV
  93   // Pseudos.
  94   IsRVVWideningReductionShift = HasVecPolicyOpShift + 1,
  95   IsRVVWideningReductionMask = 1 << IsRVVWideningReductionShift,
  96
  97   // Does this instruction care about mask policy. If it is not, the mask policy
  98   // could be either agnostic or undisturbed. For example, unmasked, store, and
  99   // reduction operations result would not be affected by mask policy, so
 100   // compiler has free to select either one.
 101   UsesMaskPolicyShift = IsRVVWideningReductionShift + 1,
 102   UsesMaskPolicyMask = 1 << UsesMaskPolicyShift,
 103
 104   // Indicates that the result can be considered sign extended from bit 31. Some
 105   // instructions with this flag aren't W instructions, but are either sign
 106   // extended from a smaller size, always outputs a small integer, or put zeros
 107   // in bits 63:31. Used by the SExtWRemoval pass.
 108   IsSignExtendingOpWShift = UsesMaskPolicyShift + 1,
 109   IsSignExtendingOpWMask = 1ULL << IsSignExtendingOpWShift,
 110
 111   HasRoundModeOpShift = IsSignExtendingOpWShift + 1,
 112   HasRoundModeOpMask = 1 << HasRoundModeOpShift,
 113
 114   UsesVXRMShift = HasRoundModeOpShift + 1,
 115   UsesVXRMMask = 1 << UsesVXRMShift,
 116 };
 117
 118 enum VLMUL : uint8_t {
 119   LMUL_1 = 0,
 120   LMUL_2,
 121   LMUL_4,
 122   LMUL_8,
 123   LMUL_RESERVED,
 124   LMUL_F8,
 125   LMUL_F4,
 126   LMUL_F2
 127 };
 128
 129 enum {
 130   TAIL_UNDISTURBED_MASK_UNDISTURBED = 0,
 131   TAIL_AGNOSTIC = 1,
 132   MASK_AGNOSTIC = 2,
 133 };
 134
 135 // Helper functions to read TSFlags.
 136 /// \returns the format of the instruction.
 137 static inline unsigned getFormat(uint64_t TSFlags) {
 138   return (TSFlags & InstFormatMask) >> InstFormatShift;
 139 }
 140 /// \returns the LMUL for the instruction.
 141 static inline VLMUL getLMul(uint64_t TSFlags) {
 142   return static_cast<VLMUL>((TSFlags & VLMulMask) >> VLMulShift);
 143 }
 144 /// \returns true if tail agnostic is enforced for the instruction.
 145 static inline bool doesForceTailAgnostic(uint64_t TSFlags) {
 146   return TSFlags & ForceTailAgnosticMask;
 147 }
 148 /// \returns true if this a _TIED pseudo.
 149 static inline bool isTiedPseudo(uint64_t TSFlags) {
 150   return TSFlags & IsTiedPseudoMask;
 151 }
 152 /// \returns true if there is a SEW operand for the instruction.
 153 static inline bool hasSEWOp(uint64_t TSFlags) {
 154   return TSFlags & HasSEWOpMask;
 155 }
 156 /// \returns true if there is a VL operand for the instruction.
 157 static inline bool hasVLOp(uint64_t TSFlags) {
 158   return TSFlags & HasVLOpMask;
 159 }
 160 /// \returns true if there is a vector policy operand for this instruction.
 161 static inline bool hasVecPolicyOp(uint64_t TSFlags) {
 162   return TSFlags & HasVecPolicyOpMask;
 163 }
 164 /// \returns true if it is a vector widening reduction instruction.
 165 static inline bool isRVVWideningReduction(uint64_t TSFlags) {
 166   return TSFlags & IsRVVWideningReductionMask;
 167 }
 168 /// \returns true if mask policy is valid for the instruction.
 169 static inline bool usesMaskPolicy(uint64_t TSFlags) {
 170   return TSFlags & UsesMaskPolicyMask;
 171 }
 172
 173 /// \returns true if there is a rounding mode operand for this instruction
 174 static inline bool hasRoundModeOp(uint64_t TSFlags) {
 175   return TSFlags & HasRoundModeOpMask;
 176 }
 177
 178 /// \returns true if this instruction uses vxrm
 179 static inline bool usesVXRM(uint64_t TSFlags) { return TSFlags & UsesVXRMMask; }
 180
 181 static inline unsigned getVLOpNum(const MCInstrDesc &Desc) {
 182   const uint64_t TSFlags = Desc.TSFlags;
 183   // This method is only called if we expect to have a VL operand, and all
 184   // instructions with VL also have SEW.
 185   assert(hasSEWOp(TSFlags) && hasVLOp(TSFlags));
 186   unsigned Offset = 2;
 187   if (hasVecPolicyOp(TSFlags))
 188     Offset = 3;
 189   return Desc.getNumOperands() - Offset;
 190 }
 191
 192 static inline unsigned getSEWOpNum(const MCInstrDesc &Desc) {
 193   const uint64_t TSFlags = Desc.TSFlags;
 194   assert(hasSEWOp(TSFlags));
 195   unsigned Offset = 1;
 196   if (hasVecPolicyOp(TSFlags))
 197     Offset = 2;
 198   return Desc.getNumOperands() - Offset;
 199 }
 200
 201 static inline unsigned getVecPolicyOpNum(const MCInstrDesc &Desc) {
 202   assert(hasVecPolicyOp(Desc.TSFlags));
 203   return Desc.getNumOperands() - 1;
 204 }
 205
 206 /// \returns  the index to the rounding mode immediate value if any, otherwise
 207 /// returns -1.
 208 static inline int getFRMOpNum(const MCInstrDesc &Desc) {
 209   const uint64_t TSFlags = Desc.TSFlags;
 210   if (!hasRoundModeOp(TSFlags) || usesVXRM(TSFlags))
 211     return -1;
 212
 213   // The operand order
 214   // --------------------------------------
 215   // | n-1 (if any)   | n-2  | n-3 | n-4 |
 216   // | policy         | sew  | vl  | frm |
 217   // --------------------------------------
 218   return getVLOpNum(Desc) - 1;
 219 }
 220
 221 /// \returns  the index to the rounding mode immediate value if any, otherwise
 222 /// returns -1.
 223 static inline int getVXRMOpNum(const MCInstrDesc &Desc) {
 224   const uint64_t TSFlags = Desc.TSFlags;
 225   if (!hasRoundModeOp(TSFlags) || !usesVXRM(TSFlags))
 226     return -1;
 227   // The operand order
 228   // --------------------------------------
 229   // | n-1 (if any)   | n-2  | n-3 | n-4  |
 230   // | policy         | sew  | vl  | vxrm |
 231   // --------------------------------------
 232   return getVLOpNum(Desc) - 1;
 233 }
 234
 235 // Is the first def operand tied to the first use operand. This is true for
 236 // vector pseudo instructions that have a merge operand for tail/mask
 237 // undisturbed. It's also true for vector FMA instructions where one of the
 238 // operands is also the destination register.
 239 static inline bool isFirstDefTiedToFirstUse(const MCInstrDesc &Desc) {
 240   return Desc.getNumDefs() < Desc.getNumOperands() &&
 241          Desc.getOperandConstraint(Desc.getNumDefs(), MCOI::TIED_TO) == 0;
 242 }
 243
 244 // RISC-V Specific Machine Operand Flags
 245 enum {
 246   MO_None = 0,
 247   MO_CALL = 1,
 248   MO_PLT = 2,
 249   MO_LO = 3,
 250   MO_HI = 4,
 251   MO_PCREL_LO = 5,
 252   MO_PCREL_HI = 6,
 253   MO_GOT_HI = 7,
 254   MO_TPREL_LO = 8,
 255   MO_TPREL_HI = 9,
 256   MO_TPREL_ADD = 10,
 257   MO_TLS_GOT_HI = 11,
 258   MO_TLS_GD_HI = 12,
 259
 260   // Used to differentiate between target-specific "direct" flags and "bitmask"
 261   // flags. A machine operand can only have one "direct" flag, but can have
 262   // multiple "bitmask" flags.
 263   MO_DIRECT_FLAG_MASK = 15
 264 };
 265 } // namespace RISCVII
 266
 267 namespace RISCVOp {
 268 enum OperandType : unsigned {
 269   OPERAND_FIRST_RISCV_IMM = MCOI::OPERAND_FIRST_TARGET,
 270   OPERAND_UIMM1 = OPERAND_FIRST_RISCV_IMM,
 271   OPERAND_UIMM2,
 272   OPERAND_UIMM2_LSB0,
 273   OPERAND_UIMM3,
 274   OPERAND_UIMM4,
 275   OPERAND_UIMM5,
 276   OPERAND_UIMM6,
 277   OPERAND_UIMM7,
 278   OPERAND_UIMM7_LSB00,
 279   OPERAND_UIMM8_LSB00,
 280   OPERAND_UIMM8,
 281   OPERAND_UIMM8_LSB000,
 282   OPERAND_UIMM8_GE32,
 283   OPERAND_UIMM9_LSB000,
 284   OPERAND_UIMM10_LSB00_NONZERO,
 285   OPERAND_UIMM12,
 286   OPERAND_ZERO,
 287   OPERAND_SIMM5,
 288   OPERAND_SIMM5_PLUS1,
 289   OPERAND_SIMM6,
 290   OPERAND_SIMM6_NONZERO,
 291   OPERAND_SIMM10_LSB0000_NONZERO,
 292   OPERAND_SIMM12,
 293   OPERAND_SIMM12_LSB00000,
 294   OPERAND_UIMM20,
 295   OPERAND_UIMMLOG2XLEN,
 296   OPERAND_UIMMLOG2XLEN_NONZERO,
 297   OPERAND_CLUI_IMM,
 298   OPERAND_VTYPEI10,
 299   OPERAND_VTYPEI11,
 300   OPERAND_RVKRNUM,
 301   OPERAND_RVKRNUM_0_7,
 302   OPERAND_RVKRNUM_1_10,
 303   OPERAND_RVKRNUM_2_14,
 304   OPERAND_LAST_RISCV_IMM = OPERAND_RVKRNUM_2_14,
 305   // Operand is either a register or uimm5, this is used by V extension pseudo
 306   // instructions to represent a value that be passed as AVL to either vsetvli
 307   // or vsetivli.
 308   OPERAND_AVL,
 309 };
 310 } // namespace RISCVOp
 311
 312 // Describes the predecessor/successor bits used in the FENCE instruction.
 313 namespace RISCVFenceField {
 314 enum FenceField {
 315   I = 8,
 316   O = 4,
 317   R = 2,
 318   W = 1
 319 };
 320 }
 321
 322 // Describes the supported floating point rounding mode encodings.
 323 namespace RISCVFPRndMode {
 324 enum RoundingMode {
 325   RNE = 0,
 326   RTZ = 1,
 327   RDN = 2,
 328   RUP = 3,
 329   RMM = 4,
 330   DYN = 7,
 331   Invalid
 332 };
 333
 334 inline static StringRef roundingModeToString(RoundingMode RndMode) {
 335   switch (RndMode) {
 336   default:
 337     llvm_unreachable("Unknown floating point rounding mode");
 338   case RISCVFPRndMode::RNE:
 339     return "rne";
 340   case RISCVFPRndMode::RTZ:
 341     return "rtz";
 342   case RISCVFPRndMode::RDN:
 343     return "rdn";
 344   case RISCVFPRndMode::RUP:
 345     return "rup";
 346   case RISCVFPRndMode::RMM:
 347     return "rmm";
 348   case RISCVFPRndMode::DYN:
 349     return "dyn";
 350   }
 351 }
 352
 353 inline static RoundingMode stringToRoundingMode(StringRef Str) {
 354   return StringSwitch<RoundingMode>(Str)
 355       .Case("rne", RISCVFPRndMode::RNE)
 356       .Case("rtz", RISCVFPRndMode::RTZ)
 357       .Case("rdn", RISCVFPRndMode::RDN)
 358       .Case("rup", RISCVFPRndMode::RUP)
 359       .Case("rmm", RISCVFPRndMode::RMM)
 360       .Case("dyn", RISCVFPRndMode::DYN)
 361       .Default(RISCVFPRndMode::Invalid);
 362 }
 363
 364 inline static bool isValidRoundingMode(unsigned Mode) {
 365   switch (Mode) {
 366   default:
 367     return false;
 368   case RISCVFPRndMode::RNE:
 369   case RISCVFPRndMode::RTZ:
 370   case RISCVFPRndMode::RDN:
 371   case RISCVFPRndMode::RUP:
 372   case RISCVFPRndMode::RMM:
 373   case RISCVFPRndMode::DYN:
 374     return true;
 375   }
 376 }
 377 } // namespace RISCVFPRndMode
 378
 379 //===----------------------------------------------------------------------===//
 380 // Floating-point Immediates
 381 //
 382
 383 namespace RISCVLoadFPImm {
 384 float getFPImm(unsigned Imm);
 385
 386 /// getLoadFPImm - Return a 5-bit binary encoding of the floating-point
 387 /// immediate value. If the value cannot be represented as a 5-bit binary
 388 /// encoding, then return -1.
 389 int getLoadFPImm(APFloat FPImm);
 390 } // namespace RISCVLoadFPImm
 391
 392 namespace RISCVSysReg {
 393 struct SysReg {
 394   const char *Name;
 395   const char *DeprecatedName;
 396   unsigned Encoding;
 397   // FIXME: add these additional fields when needed.
 398   // Privilege Access: Read, Write, Read-Only.
 399   // unsigned ReadWrite;
 400   // Privilege Mode: User, System or Machine.
 401   // unsigned Mode;
 402   // Check field name.
 403   // unsigned Extra;
 404   // Register number without the privilege bits.
 405   // unsigned Number;
 406   FeatureBitset FeaturesRequired;
 407   bool isRV32Only;
 408
 409   bool haveRequiredFeatures(const FeatureBitset &ActiveFeatures) const {
 410     // Not in 32-bit mode.
 411     if (isRV32Only && ActiveFeatures[RISCV::Feature64Bit])
 412       return false;
 413     // No required feature associated with the system register.
 414     if (FeaturesRequired.none())
 415       return true;
 416     return (FeaturesRequired & ActiveFeatures) == FeaturesRequired;
 417   }
 418
 419   bool haveVendorRequiredFeatures(const FeatureBitset &ActiveFeatures) const {
 420     // Not in 32-bit mode.
 421     if (isRV32Only && ActiveFeatures[RISCV::Feature64Bit])
 422       return false;
 423     // No required feature associated with the system register.
 424     if (FeaturesRequired.none())
 425       return false;
 426     return (FeaturesRequired & ActiveFeatures) == FeaturesRequired;
 427   }
 428 };
 429
 430 struct SiFiveReg : SysReg {};
 431
 432 #define GET_SysRegsList_DECL
 433 #define GET_SiFiveRegsList_DECL
 434 #include "RISCVGenSearchableTables.inc"
 435 } // end namespace RISCVSysReg
 436
 437 namespace RISCVInsnOpcode {
 438 struct RISCVOpcode {
 439   const char *Name;
 440   unsigned Value;
 441 };
 442
 443 #define GET_RISCVOpcodesList_DECL
 444 #include "RISCVGenSearchableTables.inc"
 445 } // end namespace RISCVInsnOpcode
 446
 447 namespace RISCVABI {
 448
 449 enum ABI {
 450   ABI_ILP32,
 451   ABI_ILP32F,
 452   ABI_ILP32D,
 453   ABI_ILP32E,
 454   ABI_LP64,
 455   ABI_LP64F,
 456   ABI_LP64D,
 457   ABI_LP64E,
 458   ABI_Unknown
 459 };
 460
 461 // Returns the target ABI, or else a StringError if the requested ABIName is
 462 // not supported for the given TT and FeatureBits combination.
 463 ABI computeTargetABI(const Triple &TT, const FeatureBitset &FeatureBits,
 464                      StringRef ABIName);
 465
 466 ABI getTargetABI(StringRef ABIName);
 467
 468 // Returns the register used to hold the stack pointer after realignment.
 469 MCRegister getBPReg();
 470
 471 // Returns the register holding shadow call stack pointer.
 472 MCRegister getSCSPReg();
 473
 474 } // namespace RISCVABI
 475
 476 namespace RISCVFeatures {
 477
 478 // Validates if the given combination of features are valid for the target
 479 // triple. Exits with report_fatal_error if not.
 480 void validate(const Triple &TT, const FeatureBitset &FeatureBits);
 481
 482 llvm::Expected<std::unique_ptr<RISCVISAInfo>>
 483 parseFeatureBits(bool IsRV64, const FeatureBitset &FeatureBits);
 484
 485 } // namespace RISCVFeatures
 486
 487 namespace RISCVVType {
 488 // Is this a SEW value that can be encoded into the VTYPE format.
 489 inline static bool isValidSEW(unsigned SEW) {
 490   return isPowerOf2_32(SEW) && SEW >= 8 && SEW <= 1024;
 491 }
 492
 493 // Is this a LMUL value that can be encoded into the VTYPE format.
 494 inline static bool isValidLMUL(unsigned LMUL, bool Fractional) {
 495   return isPowerOf2_32(LMUL) && LMUL <= 8 && (!Fractional || LMUL != 1);
 496 }
 497
 498 unsigned encodeVTYPE(RISCVII::VLMUL VLMUL, unsigned SEW, bool TailAgnostic,
 499                      bool MaskAgnostic);
 500
 501 inline static RISCVII::VLMUL getVLMUL(unsigned VType) {
 502   unsigned VLMUL = VType & 0x7;
 503   return static_cast<RISCVII::VLMUL>(VLMUL);
 504 }
 505
 506 // Decode VLMUL into 1,2,4,8 and fractional indicator.
 507 std::pair<unsigned, bool> decodeVLMUL(RISCVII::VLMUL VLMUL);
 508
 509 inline static RISCVII::VLMUL encodeLMUL(unsigned LMUL, bool Fractional) {
 510   assert(isValidLMUL(LMUL, Fractional) && "Unsupported LMUL");
 511   unsigned LmulLog2 = Log2_32(LMUL);
 512   return static_cast<RISCVII::VLMUL>(Fractional ? 8 - LmulLog2 : LmulLog2);
 513 }
 514
 515 inline static unsigned decodeVSEW(unsigned VSEW) {
 516   assert(VSEW < 8 && "Unexpected VSEW value");
 517   return 1 << (VSEW + 3);
 518 }
 519
 520 inline static unsigned encodeSEW(unsigned SEW) {
 521   assert(isValidSEW(SEW) && "Unexpected SEW value");
 522   return Log2_32(SEW) - 3;
 523 }
 524
 525 inline static unsigned getSEW(unsigned VType) {
 526   unsigned VSEW = (VType >> 3) & 0x7;
 527   return decodeVSEW(VSEW);
 528 }
 529
 530 inline static bool isTailAgnostic(unsigned VType) { return VType & 0x40; }
 531
 532 inline static bool isMaskAgnostic(unsigned VType) { return VType & 0x80; }
 533
 534 void printVType(unsigned VType, raw_ostream &OS);
 535
 536 unsigned getSEWLMULRatio(unsigned SEW, RISCVII::VLMUL VLMul);
 537
 538 std::optional<RISCVII::VLMUL>
 539 getSameRatioLMUL(unsigned SEW, RISCVII::VLMUL VLMUL, unsigned EEW);
 540 } // namespace RISCVVType
 541
 542 namespace RISCVRVC {
 543 bool compress(MCInst &OutInst, const MCInst &MI, const MCSubtargetInfo &STI);
 544 bool uncompress(MCInst &OutInst, const MCInst &MI, const MCSubtargetInfo &STI);
 545 } // namespace RISCVRVC
 546
 547 namespace RISCVZC {
 548 enum RLISTENCODE {
 549   RA = 4,
 550   RA_S0,
 551   RA_S0_S1,
 552   RA_S0_S2,
 553   RA_S0_S3,
 554   RA_S0_S4,
 555   RA_S0_S5,
 556   RA_S0_S6,
 557   RA_S0_S7,
 558   RA_S0_S8,
 559   RA_S0_S9,
 560   // note - to include s10, s11 must also be included
 561   RA_S0_S11,
 562   INVALID_RLIST,
 563 };
 564
 565 inline unsigned encodeRlist(MCRegister EndReg, bool IsRV32E = false) {
 566   assert((!IsRV32E || EndReg <= RISCV::X9) && "Invalid Rlist for RV32E");
 567   switch (EndReg) {
 568   case RISCV::X1:
 569     return RLISTENCODE::RA;
 570   case RISCV::X8:
 571     return RLISTENCODE::RA_S0;
 572   case RISCV::X9:
 573     return RLISTENCODE::RA_S0_S1;
 574   case RISCV::X18:
 575     return RLISTENCODE::RA_S0_S2;
 576   case RISCV::X19:
 577     return RLISTENCODE::RA_S0_S3;
 578   case RISCV::X20:
 579     return RLISTENCODE::RA_S0_S4;
 580   case RISCV::X21:
 581     return RLISTENCODE::RA_S0_S5;
 582   case RISCV::X22:
 583     return RLISTENCODE::RA_S0_S6;
 584   case RISCV::X23:
 585     return RLISTENCODE::RA_S0_S7;
 586   case RISCV::X24:
 587     return RLISTENCODE::RA_S0_S8;
 588   case RISCV::X25:
 589     return RLISTENCODE::RA_S0_S9;
 590   case RISCV::X26:
 591     return RLISTENCODE::INVALID_RLIST;
 592   case RISCV::X27:
 593     return RLISTENCODE::RA_S0_S11;
 594   default:
 595     llvm_unreachable("Undefined input.");
 596   }
 597 }
 598
 599 inline static unsigned getStackAdjBase(unsigned RlistVal, bool IsRV64,
 600                                        bool IsEABI) {
 601   assert(RlistVal != RLISTENCODE::INVALID_RLIST &&
 602          "{ra, s0-s10} is not supported, s11 must be included.");
 603   if (IsEABI)
 604     return 16;
 605   if (!IsRV64) {
 606     switch (RlistVal) {
 607     case RLISTENCODE::RA:
 608     case RLISTENCODE::RA_S0:
 609     case RLISTENCODE::RA_S0_S1:
 610     case RLISTENCODE::RA_S0_S2:
 611       return 16;
 612     case RLISTENCODE::RA_S0_S3:
 613     case RLISTENCODE::RA_S0_S4:
 614     case RLISTENCODE::RA_S0_S5:
 615     case RLISTENCODE::RA_S0_S6:
 616       return 32;
 617     case RLISTENCODE::RA_S0_S7:
 618     case RLISTENCODE::RA_S0_S8:
 619     case RLISTENCODE::RA_S0_S9:
 620       return 48;
 621     case RLISTENCODE::RA_S0_S11:
 622       return 64;
 623     }
 624   } else {
 625     switch (RlistVal) {
 626     case RLISTENCODE::RA:
 627     case RLISTENCODE::RA_S0:
 628       return 16;
 629     case RLISTENCODE::RA_S0_S1:
 630     case RLISTENCODE::RA_S0_S2:
 631       return 32;
 632     case RLISTENCODE::RA_S0_S3:
 633     case RLISTENCODE::RA_S0_S4:
 634       return 48;
 635     case RLISTENCODE::RA_S0_S5:
 636     case RLISTENCODE::RA_S0_S6:
 637       return 64;
 638     case RLISTENCODE::RA_S0_S7:
 639     case RLISTENCODE::RA_S0_S8:
 640       return 80;
 641     case RLISTENCODE::RA_S0_S9:
 642       return 96;
 643     case RLISTENCODE::RA_S0_S11:
 644       return 112;
 645     }
 646   }
 647   llvm_unreachable("Unexpected RlistVal");
 648 }
 649
 650 inline static bool getSpimm(unsigned RlistVal, unsigned &SpimmVal,
 651                             int64_t StackAdjustment, bool IsRV64, bool IsEABI) {
 652   if (RlistVal == RLISTENCODE::INVALID_RLIST)
 653     return false;
 654   unsigned stackAdj = getStackAdjBase(RlistVal, IsRV64, IsEABI);
 655   SpimmVal = (StackAdjustment - stackAdj) / 16;
 656   if (SpimmVal > 3)
 657     return false;
 658   return true;
 659 }
 660
 661 void printRlist(unsigned SlistEncode, raw_ostream &OS);
 662 void printSpimm(int64_t Spimm, raw_ostream &OS);
 663 } // namespace RISCVZC
 664
 665 } // namespace llvm
 666
 667 #endif