auxmath.h

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/* ////////////////////////////////////////////////////////////////////////
//
//                  INTEL CORPORATION PROPRIETARY INFORMATION
//     This software is supplied under the terms of a license agreement or
//     nondisclosure agreement with Intel Corporation and may not be copied
//     or disclosed except in accordance with the terms of that agreement.
//          Copyright(c) 2003-2005 Intel Corporation. All Rights Reserved.
//
//
//
*/

#ifndef __AUXMATH_H__
#define __AUXMATH_H__

inline unsigned int Log2(unsigned int value)
{
    int i = 31;
    for(; i >= 0; i--)
    {
        if(value&0x80000000) break;
        value = value << 1;
    }
    return i;
}

// for zero value this function returns 0,
// for value == 1 this function returns 1,
// for value == 3 this function returns 2,
// and so on
inline unsigned int MSBitPos(unsigned int value)
{
    unsigned int i = 0;
    for(; value > 0; i++) value >>= 1;
    return i;
}

// for value == 0, 1 this function returns 0,
// for value == 2, 3 this function returns 1,
// for value == 4 - 7 this function returns 2,
// and so on
inline unsigned int BitDepth(unsigned int maxValue)
{
    unsigned int bitDepth = MSBitPos(maxValue);
    if(bitDepth) bitDepth--;
    return bitDepth;
}

inline unsigned int Mod2(unsigned int value, unsigned int order)
{
    return value - ((value >> order) << order);
}

inline unsigned int RShiftCeil(unsigned int value, unsigned int order)
{
    return ( value + ( (1u << order) - 1u ) ) >> order;
}

inline unsigned int RShiftFloor(unsigned int value, unsigned int order)
{
    return value  >> order;
}

inline unsigned int DivCeil(unsigned int value, unsigned int divizor)
{
    return ( (value + divizor - 1u) / divizor );
}

inline unsigned int RoundCenterU(double value)
{
    return (unsigned int)(value + 0.5);
}


#endif // __AUXMATH_H__