uvg266/src/uvg_math.h

68 lines
2.4 KiB
C

#ifndef MATH_H_
#define MATH_H_
/*****************************************************************************
* This file is part of uvg266 VVC encoder.
*
* Copyright (c) 2021, Tampere University, ITU/ISO/IEC, project contributors
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice, this
* list of conditions and the following disclaimer in the documentation and/or
* other materials provided with the distribution.
*
* * Neither the name of the Tampere University or ITU/ISO/IEC nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
* INCLUDING NEGLIGENCE OR OTHERWISE ARISING IN ANY WAY OUT OF THE USE OF THIS
****************************************************************************/
/**
* \file
* Generic math functions
*/
#include "global.h" // IWYU pragma: keep
static INLINE unsigned uvg_math_floor_log2(unsigned value)
{
assert(value > 0);
unsigned result = 0;
for (int i = 4; i >= 0; --i) {
unsigned bits = 1ull << i;
unsigned shift = (int32_t)value >= (1 << bits) ? bits : 0;
result += shift;
value >>= shift;
}
return result;
}
static INLINE unsigned uvg_math_ceil_log2(unsigned value)
{
assert(value > 0);
// The ceil_log2 is just floor_log2 + 1, except for exact powers of 2.
return uvg_math_floor_log2(value) + ((value & (value - 1)) ? 1 : 0);
}
#endif //CHECKPOINT_H_