src/mips/constants-mips.cc

// Copyright 2011 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#if V8_TARGET_ARCH_MIPS

#include "src/mips/constants-mips.h"

namespace v8 {
namespace internal {


// -----------------------------------------------------------------------------
// Registers.


// These register names are defined in a way to match the native disassembler
// formatting. See for example the command "objdump -d <binary file>".
const char* Registers::names_[kNumSimuRegisters] = {
  "zero_reg",
  "at",
  "v0", "v1",
  "a0", "a1", "a2", "a3",
  "t0", "t1", "t2", "t3", "t4", "t5", "t6", "t7",
  "s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7",
  "t8", "t9",
  "k0", "k1",
  "gp",
  "sp",
  "fp",
  "ra",
  "LO", "HI",
  "pc"
};


// List of alias names which can be used when referring to MIPS registers.
const Registers::RegisterAlias Registers::aliases_[] = {
  {0, "zero"},
  {23, "cp"},
  {30, "s8"},
  {30, "s8_fp"},
  {kInvalidRegister, NULL}
};


const char* Registers::Name(int reg) {
  const char* result;
  if ((0 <= reg) && (reg < kNumSimuRegisters)) {
    result = names_[reg];
  } else {
    result = "noreg";
  }
  return result;
}


int Registers::Number(const char* name) {
  // Look through the canonical names.
  for (int i = 0; i < kNumSimuRegisters; i++) {
    if (strcmp(names_[i], name) == 0) {
      return i;
    }
  }

  // Look through the alias names.
  int i = 0;
  while (aliases_[i].reg != kInvalidRegister) {
    if (strcmp(aliases_[i].name, name) == 0) {
      return aliases_[i].reg;
    }
    i++;
  }

  // No register with the reguested name found.
  return kInvalidRegister;
}


const char* FPURegisters::names_[kNumFPURegisters] = {
  "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", "f8", "f9", "f10", "f11",
  "f12", "f13", "f14", "f15", "f16", "f17", "f18", "f19", "f20", "f21",
  "f22", "f23", "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31"
};


// List of alias names which can be used when referring to MIPS registers.
const FPURegisters::RegisterAlias FPURegisters::aliases_[] = {
  {kInvalidRegister, NULL}
};


const char* FPURegisters::Name(int creg) {
  const char* result;
  if ((0 <= creg) && (creg < kNumFPURegisters)) {
    result = names_[creg];
  } else {
    result = "nocreg";
  }
  return result;
}


int FPURegisters::Number(const char* name) {
  // Look through the canonical names.
  for (int i = 0; i < kNumFPURegisters; i++) {
    if (strcmp(names_[i], name) == 0) {
      return i;
    }
  }

  // Look through the alias names.
  int i = 0;
  while (aliases_[i].creg != kInvalidRegister) {
    if (strcmp(aliases_[i].name, name) == 0) {
      return aliases_[i].creg;
    }
    i++;
  }

  // No Cregister with the reguested name found.
  return kInvalidFPURegister;
}


// -----------------------------------------------------------------------------
// Instructions.

bool Instruction::IsForbiddenAfterBranchInstr(Instr instr) {
  Opcode opcode = static_cast<Opcode>(instr & kOpcodeMask);
  switch (opcode) {
    case J:
    case JAL:
    case BEQ:
    case BNE:
    case BLEZ:  // POP06 bgeuc/bleuc, blezalc, bgezalc
    case BGTZ:  // POP07 bltuc/bgtuc, bgtzalc, bltzalc
    case BEQL:
    case BNEL:
    case BLEZL:  // POP26 bgezc, blezc, bgec/blec
    case BGTZL:  // POP27 bgtzc, bltzc, bltc/bgtc
    case BC:
    case BALC:
    case POP10:  // beqzalc, bovc, beqc
    case POP30:  // bnezalc, bvnc, bnec
    case POP66:  // beqzc, jic
    case POP76:  // bnezc, jialc
      return true;
    case REGIMM:
      switch (instr & kRtFieldMask) {
        case BLTZ:
        case BGEZ:
        case BLTZAL:
        case BGEZAL:
          return true;
        default:
          return false;
      }
      break;
    case SPECIAL:
      switch (instr & kFunctionFieldMask) {
        case JR:
        case JALR:
          return true;
        default:
          return false;
      }
      break;
    case COP1:
      switch (instr & kRsFieldMask) {
        case BC1:
        case BC1EQZ:
        case BC1NEZ:
          return true;
          break;
        default:
          return false;
      }
      break;
    default:
      return false;
  }
}


bool Instruction::IsLinkingInstruction() const {
  switch (OpcodeFieldRaw()) {
    case JAL:
      return true;
    case POP76:
      if (RsFieldRawNoAssert() == JIALC)
        return true;  // JIALC
      else
        return false;  // BNEZC
    case REGIMM:
      switch (RtFieldRaw()) {
        case BGEZAL:
        case BLTZAL:
          return true;
      default:
        return false;
      }
    case SPECIAL:
      switch (FunctionFieldRaw()) {
        case JALR:
          return true;
        default:
          return false;
      }
    default:
      return false;
  }
}


bool Instruction::IsTrap() const {
  if (OpcodeFieldRaw() != SPECIAL) {
    return false;
  } else {
    switch (FunctionFieldRaw()) {
      case BREAK:
      case TGE:
      case TGEU:
      case TLT:
      case TLTU:
      case TEQ:
      case TNE:
        return true;
      default:
        return false;
    }
  }
}


}  // namespace internal
}  // namespace v8

#endif  // V8_TARGET_ARCH_MIPS