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Diffstat (limited to 'compat/bitops.h')
| -rw-r--r-- | compat/bitops.h | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/compat/bitops.h b/compat/bitops.h new file mode 100644 index 000000000000..31979a20f458 --- /dev/null +++ b/compat/bitops.h @@ -0,0 +1,188 @@ +/* $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_ */ |