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Common: Move floating-point utility functions to FloatUtils.h/.cpp

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Keeps all of the floating-point utility functions in their own file to
keep them all together. This also provides a place for other
general-purpose floating-point functions to be added in the future,
which will be necessary when improving the flag-setting within the
interpreter.
This commit is contained in:
Lioncash
2018-05-07 01:18:41 -04:00
parent 756ef54ab6
commit 86018b503b
17 changed files with 474 additions and 434 deletions
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116
Source/Core/Common/MathUtil.h
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@ -17,32 +17,6 @@
namespace MathUtil
{
template <typename T>
constexpr T SNANConstant()
{
return std::numeric_limits<T>::signaling_NaN();
}
#ifdef _MSC_VER
// MSVC needs a workaround, because its std::numeric_limits<double>::signaling_NaN()
// will use __builtin_nans, which is improperly handled by the compiler and generates
// a bad constant. Here we go back to the version MSVC used before the builtin.
// TODO: Remove this and use numeric_limits directly whenever this bug is fixed.
template <>
constexpr double SNANConstant()
{
return (_CSTD _Snan._Double);
}
template <>
constexpr float SNANConstant()
{
return (_CSTD _Snan._Float);
}
#endif
template <class T>
constexpr T Clamp(const T val, const T& min, const T& max)
{
@ -55,96 +29,6 @@ constexpr bool IsPow2(T imm)
return imm > 0 && (imm & (imm - 1)) == 0;
}
// The most significant bit of the fraction is an is-quiet bit on all architectures we care about.
static const u64 DOUBLE_SIGN = 0x8000000000000000ULL, DOUBLE_EXP = 0x7FF0000000000000ULL,
DOUBLE_FRAC = 0x000FFFFFFFFFFFFFULL, DOUBLE_ZERO = 0x0000000000000000ULL,
DOUBLE_QBIT = 0x0008000000000000ULL;
static const u32 FLOAT_SIGN = 0x80000000, FLOAT_EXP = 0x7F800000, FLOAT_FRAC = 0x007FFFFF,
FLOAT_ZERO = 0x00000000;
union IntDouble
{
double d;
u64 i;
explicit IntDouble(u64 _i) : i(_i) {}
explicit IntDouble(double _d) : d(_d) {}
};
union IntFloat
{
float f;
u32 i;
explicit IntFloat(u32 _i) : i(_i) {}
explicit IntFloat(float _f) : f(_f) {}
};
inline bool IsQNAN(double d)
{
IntDouble x(d);
return ((x.i & DOUBLE_EXP) == DOUBLE_EXP) && ((x.i & DOUBLE_QBIT) == DOUBLE_QBIT);
}
inline bool IsSNAN(double d)
{
IntDouble x(d);
return ((x.i & DOUBLE_EXP) == DOUBLE_EXP) && ((x.i & DOUBLE_FRAC) != DOUBLE_ZERO) &&
((x.i & DOUBLE_QBIT) == DOUBLE_ZERO);
}
inline float FlushToZero(float f)
{
IntFloat x(f);
if ((x.i & FLOAT_EXP) == 0)
{
x.i &= FLOAT_SIGN; // turn into signed zero
}
return x.f;
}
inline double FlushToZero(double d)
{
IntDouble x(d);
if ((x.i & DOUBLE_EXP) == 0)
{
x.i &= DOUBLE_SIGN; // turn into signed zero
}
return x.d;
}
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);
// More efficient float version.
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);
template <class T>
struct Rectangle
{