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// Copyright 2018 Dolphin Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later
#pragma once
#include <array>
#include <bit>
#include <limits>
#include "Common/CommonTypes.h"
namespace Common
{
template <typename T>
constexpr T SNANConstant()
{
return std::numeric_limits<T>::signaling_NaN();
}
// The most significant bit of the fraction is an is-quiet bit on all architectures we care about.
static constexpr u64 DOUBLE_QBIT = 0x0008000000000000ULL;
static constexpr u64 DOUBLE_SIGN = 0x8000000000000000ULL;
static constexpr u64 DOUBLE_EXP = 0x7FF0000000000000ULL;
static constexpr u64 DOUBLE_FRAC = 0x000FFFFFFFFFFFFFULL;
static constexpr u64 DOUBLE_ZERO = 0x0000000000000000ULL;
static constexpr int DOUBLE_EXP_WIDTH = 11;
static constexpr int DOUBLE_FRAC_WIDTH = 52;
static constexpr u32 FLOAT_SIGN = 0x80000000;
static constexpr u32 FLOAT_EXP = 0x7F800000;
static constexpr u32 FLOAT_FRAC = 0x007FFFFF;
static constexpr u32 FLOAT_ZERO = 0x00000000;
static constexpr int FLOAT_EXP_WIDTH = 8;
static constexpr int FLOAT_FRAC_WIDTH = 23;
inline bool IsQNAN(double d)
{
const u64 i = std::bit_cast<u64>(d);
return ((i & DOUBLE_EXP) == DOUBLE_EXP) && ((i & DOUBLE_QBIT) == DOUBLE_QBIT);
}
inline bool IsSNAN(double d)
{
const u64 i = std::bit_cast<u64>(d);
return ((i & DOUBLE_EXP) == DOUBLE_EXP) && ((i & DOUBLE_FRAC) != DOUBLE_ZERO) &&
((i & DOUBLE_QBIT) == DOUBLE_ZERO);
}
inline float FlushToZero(float f)
{
u32 i = std::bit_cast<u32>(f);
if ((i & FLOAT_EXP) == 0)
{
// Turn into signed zero
i &= FLOAT_SIGN;
}
return std::bit_cast<float>(i);
}
inline double FlushToZero(double d)
{
u64 i = std::bit_cast<u64>(d);
if ((i & DOUBLE_EXP) == 0)
{
// Turn into signed zero
i &= DOUBLE_SIGN;
}
return std::bit_cast<double>(i);
}
inline double MakeQuiet(double d)
{
const u64 integral = std::bit_cast<u64>(d) | Common::DOUBLE_QBIT;
return std::bit_cast<double>(integral);
}
enum PPCFpClass
{
PPC_FPCLASS_QNAN = 0x11,
PPC_FPCLASS_NINF = 0x9,
PPC_FPCLASS_NN = 0x8,
PPC_FPCLASS_ND = 0x18,
PPC_FPCLASS_NZ = 0x12,
PPC_FPCLASS_PZ = 0x2,
PPC_FPCLASS_PD = 0x14,
PPC_FPCLASS_PN = 0x4,
PPC_FPCLASS_PINF = 0x5,
};
// Uses PowerPC conventions for the return value, so it can be easily
// used directly in CPU emulation.
u32 ClassifyDouble(double dvalue);
u32 ClassifyFloat(float fvalue);
struct BaseAndDec
{
int m_base;
int m_dec;
};
extern const std::array<BaseAndDec, 32> frsqrte_expected;
extern const std::array<BaseAndDec, 32> fres_expected;
// PowerPC approximation algorithms
double ApproximateReciprocalSquareRoot(double val);
double ApproximateReciprocal(double val);
} // namespace Common
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