src/third_party/mozjs-45/js/src/jit/mips64/Architecture-mips64.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * vim: set ts=8 sts=4 et sw=4 tw=99:
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef jit_mips64_Architecture_mips64_h
#define jit_mips64_Architecture_mips64_h

#include "mozilla/MathAlgorithms.h"

#include <limits.h>
#include <stdint.h>

#include "jit/mips-shared/Architecture-mips-shared.h"

#include "js/Utility.h"

namespace js {
namespace jit {

// Shadow stack space is not required on MIPS64.
static const uint32_t ShadowStackSpace = 0;

// MIPS64 have 64 bit floating-point coprocessor. There are 32 double
// precision register which can also be used as single precision registers.
class FloatRegisters : public FloatRegistersMIPSShared
{
  public:
    enum ContentType {
        Single,
        Double,
        NumTypes
    };

    static const char* GetName(uint32_t i) {
        MOZ_ASSERT(i < TotalPhys);
        return FloatRegistersMIPSShared::GetName(Encoding(i));
    }

    static Encoding FromName(const char* name);

    static const uint32_t Total = 32 * NumTypes;
    static const uint32_t Allocatable = 60;
    // When saving all registers we only need to do is save double registers.
    static const uint32_t TotalPhys = 32;

    static_assert(sizeof(SetType) * 8 >= Total,
                  "SetType should be large enough to enumerate all registers.");

    // Magic values which are used to duplicate a mask of physical register for
    // a specific type of register. A multiplication is used to copy and shift
    // the bits of the physical register mask.
    static const SetType SpreadSingle = SetType(1) << (uint32_t(Single) * TotalPhys);
    static const SetType SpreadDouble = SetType(1) << (uint32_t(Double) * TotalPhys);
    static const SetType SpreadScalar = SpreadSingle | SpreadDouble;
    static const SetType SpreadVector = 0;
    static const SetType Spread = SpreadScalar | SpreadVector;

    static const SetType AllPhysMask = ((SetType(1) << TotalPhys) - 1);
    static const SetType AllMask = AllPhysMask * Spread;
    static const SetType AllDoubleMask = AllPhysMask * SpreadDouble;

    static const SetType NonVolatileMask =
        ( (1U << FloatRegisters::f24) |
          (1U << FloatRegisters::f25) |
          (1U << FloatRegisters::f26) |
          (1U << FloatRegisters::f27) |
          (1U << FloatRegisters::f28) |
          (1U << FloatRegisters::f29) |
          (1U << FloatRegisters::f30) |
          (1U << FloatRegisters::f31)
        ) * SpreadScalar
        | AllPhysMask * SpreadVector;

    static const SetType VolatileMask = AllMask & ~NonVolatileMask;

    static const SetType WrapperMask = VolatileMask;

    static const SetType NonAllocatableMask =
        ( // f21 and f23 are MIPS scratch float registers.
          (1U << FloatRegisters::f21) |
          (1U << FloatRegisters::f23)
        ) * Spread;

    // Registers that can be allocated without being saved, generally.
    static const SetType TempMask = VolatileMask & ~NonAllocatableMask;

    static const SetType AllocatableMask = AllMask & ~NonAllocatableMask;
};

template <typename T>
class TypedRegisterSet;

class FloatRegister : public FloatRegisterMIPSShared
{
  public:
    typedef FloatRegisters Codes;
    typedef size_t Code;
    typedef Codes::Encoding Encoding;
    typedef Codes::ContentType ContentType;

    Encoding reg_: 6;
  private:
    ContentType kind_ : 3;

  public:
    MOZ_CONSTEXPR FloatRegister(uint32_t r, ContentType kind = Codes::Double)
      : reg_(Encoding(r)), kind_(kind)
    { }
    MOZ_CONSTEXPR FloatRegister()
      : reg_(Encoding(FloatRegisters::invalid_freg)), kind_(Codes::Double)
    { }

    bool operator==(const FloatRegister& other) const {
        MOZ_ASSERT(!isInvalid());
        MOZ_ASSERT(!other.isInvalid());
        return kind_ == other.kind_ && reg_ == other.reg_;
    }
    bool equiv(const FloatRegister& other) const { return other.kind_ == kind_; }
    size_t size() const { return (kind_ == Codes::Double) ? sizeof(double) : sizeof (float); }
    bool isInvalid() const {
        return reg_ == FloatRegisters::invalid_freg;
    }

    bool isSingle() const { return kind_ == Codes::Single; }
    bool isDouble() const { return kind_ == Codes::Double; }

    FloatRegister singleOverlay() const;
    FloatRegister doubleOverlay() const;

    FloatRegister asSingle() const { return singleOverlay(); }
    FloatRegister asDouble() const { return doubleOverlay(); }
    FloatRegister asSimd128() const { MOZ_CRASH("NYI"); }

    Code code() const {
        MOZ_ASSERT(!isInvalid());
        return Code(reg_ | (kind_ << 5));
    }
    Encoding encoding() const {
        MOZ_ASSERT(!isInvalid());
        MOZ_ASSERT(uint32_t(reg_) < Codes::TotalPhys);
        return reg_;
    }
    uint32_t id() const {
        return reg_;
    }
    static FloatRegister FromCode(uint32_t i) {
        uint32_t code = i & 0x1f;
        uint32_t kind = i >> 5;
        return FloatRegister(Code(code), ContentType(kind));
    }

    bool volatile_() const {
        return !!((1 << reg_) & FloatRegisters::VolatileMask);
    }
    const char* name() const {
        return FloatRegisters::GetName(reg_);
    }
    bool operator != (const FloatRegister& other) const {
        return kind_ != other.kind_ || reg_ != other.reg_;
    }
    bool aliases(const FloatRegister& other) {
        return reg_ == other.reg_;
    }
    uint32_t numAliased() const {
        return 2;
    }
    void aliased(uint32_t aliasIdx, FloatRegister* ret) {
        if (aliasIdx == 0) {
            *ret = *this;
            return;
        }
        MOZ_ASSERT(aliasIdx == 1);
        if (isDouble())
          *ret = singleOverlay();
        else
          *ret = doubleOverlay();
    }
    uint32_t numAlignedAliased() const {
        return 2;
    }
    void alignedAliased(uint32_t aliasIdx, FloatRegister* ret) {
        MOZ_ASSERT(isDouble());
        if (aliasIdx == 0) {
            *ret = *this;
            return;
        }
        MOZ_ASSERT(aliasIdx == 1);
        *ret = singleOverlay();
    }

    SetType alignedOrDominatedAliasedSet() const {
        return Codes::Spread << reg_;
    }

    static Code FromName(const char* name) {
        return FloatRegisters::FromName(name);
    }
    static TypedRegisterSet<FloatRegister> ReduceSetForPush(const TypedRegisterSet<FloatRegister>& s);
    static uint32_t GetPushSizeInBytes(const TypedRegisterSet<FloatRegister>& s);
    uint32_t getRegisterDumpOffsetInBytes();
};

} // namespace jit
} // namespace js

#endif /* jit_mips64_Architecture_mips64_h */