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

// Copyright 2009 the V8 project authors. All rights reserved.
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#ifndef V8_ARM_REGISTER_ALLOCATOR_ARM_INL_H_
#define V8_ARM_REGISTER_ALLOCATOR_ARM_INL_H_

#include "v8.h"

namespace v8 {
namespace internal {

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

bool RegisterAllocator::IsReserved(Register reg) {
  return reg.is(cp) || reg.is(fp) || reg.is(sp) || reg.is(pc);
}



// The register allocator uses small integers to represent the
// non-reserved assembler registers.  The mapping is:
//
// r0 <-> 0
// r1 <-> 1
// r2 <-> 2
// r3 <-> 3
// r4 <-> 4
// r5 <-> 5
// r6 <-> 6
// r7 <-> 7
// r9 <-> 8
// r10 <-> 9
// ip <-> 10
// lr <-> 11

int RegisterAllocator::ToNumber(Register reg) {
  ASSERT(reg.is_valid() && !IsReserved(reg));
  const int kNumbers[] = {
    0,   // r0
    1,   // r1
    2,   // r2
    3,   // r3
    4,   // r4
    5,   // r5
    6,   // r6
    7,   // r7
    -1,  // cp
    8,   // r9
    9,   // r10
    -1,  // fp
    10,  // ip
    -1,  // sp
    11,  // lr
    -1   // pc
  };
  return kNumbers[reg.code()];
}


Register RegisterAllocator::ToRegister(int num) {
  ASSERT(num >= 0 && num < kNumRegisters);
  const Register kRegisters[] =
      { r0, r1, r2, r3, r4, r5, r6, r7, r9, r10, ip, lr };
  return kRegisters[num];
}


void RegisterAllocator::Initialize() {
  Reset();
  // The non-reserved r1 and lr registers are live on JS function entry.
  Use(r1);  // JS function.
  Use(lr);  // Return address.
}


} }  // namespace v8::internal

#endif  // V8_ARM_REGISTER_ALLOCATOR_ARM_INL_H_