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/* SPDX-License-Identifier: BSD-2-Clause */
/*
* Author: Jeffrey O. Hill
*
* Copyright 2012. Los Alamos National Security, LLC.
* This material was produced under U.S. Government contract
* DE-AC52-06NA25396 for Los Alamos National Laboratory (LANL),
* which is operated by Los Alamos National Security, LLC for
* the U.S. Department of Energy. The U.S. Government has rights
* to use, reproduce, and distribute this software. NEITHER THE
* GOVERNMENT NOR LOS ALAMOS NATIONAL SECURITY, LLC MAKES ANY
* WARRANTY, EXPRESS OR IMPLIED, OR ASSUMES ANY LIABILITY FOR
* THE USE OF THIS SOFTWARE.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* 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 OWNER 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 (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _NIOS2_COUNT_ZEROS_H
#define _NIOS2_COUNT_ZEROS_H
#include <stdint.h>
#include <rtems/score/bitfield.h>
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/*
* This implementation is currently much more efficient than
* the GCC provided __builtin_clz
*/
static inline unsigned _Nios2_Count_leading_zeros( uint32_t p )
{
unsigned bitIdx;
if ( p <= 0xffffu ) {
if ( p < 0x100u ) {
bitIdx = _Bitfield_Leading_zeros[ p ] + 24u;
} else {
bitIdx = _Bitfield_Leading_zeros[ p >> 8u ] + 16u;
}
} else {
p >>= 16u;
if ( p < 0x100u ) {
bitIdx = _Bitfield_Leading_zeros[ p ] + 8u;
} else {
bitIdx = _Bitfield_Leading_zeros[ p >> 8u ];
}
}
return bitIdx;
}
/*
* This implementation is currently much more efficient than
* the GCC provided __builtin_ctz
*/
static inline unsigned _Nios2_Count_trailing_zeros( uint32_t p )
{
return 31u - _Nios2_Count_leading_zeros( p & ( -p ) );
}
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* _NIOS2_COUNT_ZEROS_H */
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