CWE-ou-minkata/Sources/Plasma/NucleusLib/pnUtils/Private/pnUtMath.h

/*==LICENSE==*

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*==LICENSE==*/
/*****************************************************************************
*
*   $/Plasma20/Sources/Plasma/NucleusLib/pnUtils/Private/pnUtMath.h
*   
***/

#ifdef PLASMA20_SOURCES_PLASMA_NUCLEUSLIB_PNUTILS_PRIVATE_PNUTMATH_H
#error "Header $/Plasma20/Sources/Plasma/NucleusLib/pnUtils/Private/pnUtMath.h included more than once"
#endif
#define PLASMA20_SOURCES_PLASMA_NUCLEUSLIB_PNUTILS_PRIVATE_PNUTMATH_H


/*****************************************************************************
*
*   Calling conventions
*
***/

#ifdef _M_IX86
#define  MATHCALL  __fastcall
#else
#define  MATHCALL
#endif


/*****************************************************************************
*
*   Bit manipulation functions
*
***/

unsigned MATHCALL MathLowBitPos (dword val);
unsigned MATHCALL MathHighBitPos (dword val);

//===========================================================================
inline unsigned MathBitCount (dword val) {
    val = val - ((val >> 1) & 033333333333) - ((val >> 2) & 011111111111);
    val = ((val + (val >> 3)) & 030707070707);
    val = val + (val >> 6);
    val = (val + (val >> 12) + (val >> 24)) & 077;
    return val;
}

//===========================================================================
inline unsigned MathBitMaskCreate (unsigned count) {
    ASSERT(count <= 8 * sizeof(unsigned));
    return count ? ((2 << (count - 1)) - 1) : 0;
}

//===========================================================================
inline dword MathHighBitValue (dword val) {
    return val ? 1 << MathHighBitPos(val) : 0;
}

//===========================================================================
inline bool MathIsPow2 (unsigned val) {
    return !(val & (val - 1));
}

//===========================================================================
inline unsigned MathLowBitValue (unsigned val) {
    return val & ~(val - 1);
}

//===========================================================================
inline unsigned MathNextMultiplePow2 (unsigned val, unsigned multiple) {
    ASSERT(multiple);
    ASSERT(MathIsPow2(multiple));
    return (val + (multiple - 1)) & ~(multiple - 1);
}

//===========================================================================
inline dword MathNextPow2 (dword val) {
    return MathIsPow2(val) ? val : 1 << (MathHighBitPos(val) + 1);
}