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Rev 1888 Rev 2004
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/*
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/*
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 * Copyright (C) 2006 Ondrej Palkovsky
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 * Copyright (C) 2006 Ondrej Palkovsky
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 * All rights reserved.
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 * All rights reserved.
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 *
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * are met:
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 *
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 *
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 * - Redistributions of source code must retain the above copyright
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 * - Redistributions of source code must retain the above copyright
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 *   notice, this list of conditions and the following disclaimer.
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 *   notice, this list of conditions and the following disclaimer.
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 * - Redistributions in binary form must reproduce the above copyright
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 * - Redistributions in binary form must reproduce the above copyright
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 *   notice, this list of conditions and the following disclaimer in the
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 *   notice, this list of conditions and the following disclaimer in the
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 *   documentation and/or other materials provided with the distribution.
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 *   documentation and/or other materials provided with the distribution.
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 * - The name of the author may not be used to endorse or promote products
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 * - The name of the author may not be used to endorse or promote products
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 *   derived from this software without specific prior written permission.
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 *   derived from this software without specific prior written permission.
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 *
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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 */
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 */
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/** @addtogroup generic
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/** @addtogroup generic
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 * @{
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 * @{
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 */
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 */
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/** @file
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/** @file
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 */
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 */
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#ifndef KERN_BITOPS_H_
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#ifndef KERN_BITOPS_H_
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#define KERN_BITOPS_H_
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#define KERN_BITOPS_H_
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#include <typedefs.h>
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#include <typedefs.h>
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/** Return position of first non-zero bit from left (i.e. [log_2(arg)]).
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/** Return position of first non-zero bit from left (i.e. [log_2(arg)]).
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 *
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 *
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 * If number is zero, it returns 0
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 * If number is zero, it returns 0
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 */
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 */
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static inline int fnzb32(uint32_t arg)
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static inline int fnzb32(uint32_t arg)
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{
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{
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    int n = 0;
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    int n = 0;
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    if (arg >> 16) { arg >>= 16;n += 16;}
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    if (arg >> 16) {
- 
 
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        arg >>= 16;
- 
 
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        n += 16;
- 
 
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    }
- 
 
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    if (arg >> 8) { arg >>= 8; n += 8;}
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    if (arg >> 8) {
- 
 
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        arg >>= 8;
- 
 
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        n += 8;
- 
 
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    }
- 
 
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    if (arg >> 4) { arg >>= 4; n += 4;}
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    if (arg >> 4) {
- 
 
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        arg >>= 4;
- 
 
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        n += 4;
- 
 
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    }
- 
 
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    if (arg >> 2) { arg >>= 2; n+=2;}
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    if (arg >> 2) {
- 
 
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        arg >>= 2;
- 
 
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        n += 2;
- 
 
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    }
- 
 
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    if (arg >> 1) { arg >>= 1; n+=1;}
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    if (arg >> 1) {
- 
 
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        arg >>= 1;
- 
 
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        n += 1;
- 
 
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    }
- 
 
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    return n;
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    return n;
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}
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}
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static inline int fnzb64(uint64_t arg)
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static inline int fnzb64(uint64_t arg)
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{
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{
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    int n = 0;
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    int n = 0;
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    if (arg >> 32) { arg >>= 32;n += 32;}
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    if (arg >> 32) {
- 
 
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        arg >>= 32;
- 
 
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        n += 32;
- 
 
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    }
- 
 
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    return n + fnzb32((uint32_t) arg);
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    return n + fnzb32((uint32_t) arg);
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}
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}
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#define fnzb(x) fnzb32(x)
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#define fnzb(x) fnzb32(x)
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#endif
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#endif
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/** @}
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/** @}
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 */
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 */
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