src/x64/register-allocator-x64-inl.h

// Copyright 2009 the V8 project authors. All rights reserved.
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#ifndef V8_X64_REGISTER_ALLOCATOR_X64_INL_H_
#define V8_X64_REGISTER_ALLOCATOR_X64_INL_H_

#include "v8.h"

namespace v8 {
namespace internal {

// -------------------------------------------------------------------------
// RegisterAllocator implementation.

bool RegisterAllocator::IsReserved(Register reg) {
  return reg.is(rsp) || reg.is(rbp) || reg.is(rsi) ||
      reg.is(kScratchRegister);
}


// The register allocator uses small integers to represent the
// non-reserved assembler registers.
int RegisterAllocator::ToNumber(Register reg) {
  ASSERT(reg.is_valid() && !IsReserved(reg));
  const int kNumbers[] = {
    0,   // rax
    2,   // rcx
    3,   // rdx
    1,   // rbx
    -1,  // rsp  Stack pointer.
    -1,  // rbp  Frame pointer.
    -1,  // rsi  Context.
    4,   // rdi
    5,   // r8
    6,   // r9
    -1,  // r10  Scratch register.
    9,   // r11
    10,  // r12
    -1,  // r13  Roots array.  This is callee saved.
    7,   // r14
    8    // r15
  };
  return kNumbers[reg.code()];
}


Register RegisterAllocator::ToRegister(int num) {
  ASSERT(num >= 0 && num < kNumRegisters);
  const Register kRegisters[] =
      { rax, rbx, rcx, rdx, rdi, r8, r9, r14, r15, r11, r12 };
  return kRegisters[num];
}


void RegisterAllocator::Initialize() {
  Reset();
  // The non-reserved rdi register is live on JS function entry.
  Use(rdi);  // JS function.
}
} }  // namespace v8::internal

#endif  // V8_X64_REGISTER_ALLOCATOR_X64_INL_H_