/* $NetBSD: bitops.h,v 1.11 2012/12/07 02:27:58 christos Exp $ */
/*-
* Copyright (c) 2007, 2010 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas and Joerg Sonnenberger.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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 COMPAT_BITOPS_H
#define COMPAT_BITOPS_H
#include <stdint.h>
#include "common.h"
/*
* Find First Set functions
*/
#ifndef ffs32
static inline int __unused
ffs32(uint32_t _n)
{
int _v;
if (!_n)
return 0;
_v = 1;
if ((_n & 0x0000FFFFU) == 0) {
_n >>= 16;
_v += 16;
}
if ((_n & 0x000000FFU) == 0) {
_n >>= 8;
_v += 8;
}
if ((_n & 0x0000000FU) == 0) {
_n >>= 4;
_v += 4;
}
if ((_n & 0x00000003U) == 0) {
_n >>= 2;
_v += 2;
}
if ((_n & 0x00000001U) == 0) {
//_n >>= 1;
_v += 1;
}
return _v;
}
#endif
#ifndef ffs64
static inline int __unused
ffs64(uint64_t _n)
{
int _v;
if (!_n)
return 0;
_v = 1;
if ((_n & 0x00000000FFFFFFFFULL) == 0) {
_n >>= 32;
_v += 32;
}
if ((_n & 0x000000000000FFFFULL) == 0) {
_n >>= 16;
_v += 16;
}
if ((_n & 0x00000000000000FFULL) == 0) {
_n >>= 8;
_v += 8;
}
if ((_n & 0x000000000000000FULL) == 0) {
_n >>= 4;
_v += 4;
}
if ((_n & 0x0000000000000003ULL) == 0) {
_n >>= 2;
_v += 2;
}
if ((_n & 0x0000000000000001ULL) == 0) {
//_n >>= 1;
_v += 1;
}
return _v;
}
#endif
/*
* Find Last Set functions
*/
#ifndef fls32
static __inline int __unused
fls32(uint32_t _n)
{
int _v;
if (!_n)
return 0;
_v = 32;
if ((_n & 0xFFFF0000U) == 0) {
_n <<= 16;
_v -= 16;
}
if ((_n & 0xFF000000U) == 0) {
_n <<= 8;
_v -= 8;
}
if ((_n & 0xF0000000U) == 0) {
_n <<= 4;
_v -= 4;
}
if ((_n & 0xC0000000U) == 0) {
_n <<= 2;
_v -= 2;
}
if ((_n & 0x80000000U) == 0) {
//_n <<= 1;
_v -= 1;
}
return _v;
}
#endif
#ifndef fls64
static int __unused
fls64(uint64_t _n)
{
int _v;
if (!_n)
return 0;
_v = 64;
if ((_n & 0xFFFFFFFF00000000ULL) == 0) {
_n <<= 32;
_v -= 32;
}
if ((_n & 0xFFFF000000000000ULL) == 0) {
_n <<= 16;
_v -= 16;
}
if ((_n & 0xFF00000000000000ULL) == 0) {
_n <<= 8;
_v -= 8;
}
if ((_n & 0xF000000000000000ULL) == 0) {
_n <<= 4;
_v -= 4;
}
if ((_n & 0xC000000000000000ULL) == 0) {
_n <<= 2;
_v -= 2;
}
if ((_n & 0x8000000000000000ULL) == 0) {
//_n <<= 1;
_v -= 1;
}
return _v;
}
#endif
#endif /* COMPAT_BITOPS_H_ */
