3312af6e07
We currently use an old version of libgcrypt which results in us having fewer ciphers and missing on many other improvements. Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
124 lines
3.3 KiB
C
124 lines
3.3 KiB
C
/* bithelp.h - Some bit manipulation helpers
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* Copyright (C) 1999, 2002 Free Software Foundation, Inc.
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*
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* This file is part of Libgcrypt.
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*
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* Libgcrypt is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Lesser General Public License as
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* published by the Free Software Foundation; either version 2.1 of
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* the License, or (at your option) any later version.
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*
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* Libgcrypt is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef GCRYPT_BITHELP_H
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#define GCRYPT_BITHELP_H
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#include "types.h"
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/****************
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* Rotate the 32 bit unsigned integer X by N bits left/right
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*/
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static inline u32 rol(u32 x, int n)
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{
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return ( (x << (n&(32-1))) | (x >> ((32-n)&(32-1))) );
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}
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static inline u32 ror(u32 x, int n)
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{
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return ( (x >> (n&(32-1))) | (x << ((32-n)&(32-1))) );
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}
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static inline u64 rol64(u64 x, int n)
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{
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return ( (x << (n&(64-1))) | (x >> ((64-n)&(64-1))) );
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}
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/* Byte swap for 32-bit and 64-bit integers. If available, use compiler
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provided helpers. */
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#ifdef HAVE_BUILTIN_BSWAP32
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# define _gcry_bswap32 __builtin_bswap32
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#else
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static inline u32
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_gcry_bswap32(u32 x)
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{
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return ((rol(x, 8) & 0x00ff00ffL) | (ror(x, 8) & 0xff00ff00L));
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}
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#endif
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#ifdef HAVE_BUILTIN_BSWAP64
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# define _gcry_bswap64 __builtin_bswap64
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#else
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static inline u64
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_gcry_bswap64(u64 x)
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{
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return ((u64)_gcry_bswap32(x) << 32) | (_gcry_bswap32(x >> 32));
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}
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#endif
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/* Endian dependent byte swap operations. */
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#ifdef WORDS_BIGENDIAN
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# define le_bswap32(x) _gcry_bswap32(x)
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# define be_bswap32(x) ((u32)(x))
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# define le_bswap64(x) _gcry_bswap64(x)
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# define be_bswap64(x) ((u64)(x))
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#else
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# define le_bswap32(x) ((u32)(x))
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# define be_bswap32(x) _gcry_bswap32(x)
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# define le_bswap64(x) ((u64)(x))
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# define be_bswap64(x) _gcry_bswap64(x)
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#endif
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/* Count trailing zero bits in an unsigend int. We return an int
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because that is what gcc's builtin does. Returns the number of
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bits in X if X is 0. */
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static inline int
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_gcry_ctz (unsigned int x)
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{
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#if defined (HAVE_BUILTIN_CTZ)
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return x ? __builtin_ctz (x) : 8 * sizeof (x);
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#else
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/* See
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* http://graphics.stanford.edu/~seander/bithacks.html#ZerosOnRightModLookup
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*/
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static const unsigned char mod37[] =
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{
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sizeof (unsigned int)*8,
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0, 1, 26, 2, 23, 27, 0, 3, 16, 24, 30, 28, 11, 0, 13,
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4, 7, 17, 0, 25, 22, 31, 15, 29, 10, 12, 6, 0, 21, 14, 9,
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5, 20, 8, 19, 18
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};
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return (int)mod37[(-x & x) % 37];
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#endif
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}
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/* Count trailing zero bits in an u64. We return an int because that
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is what gcc's builtin does. Returns the number of bits in X if X
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is 0. */
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static inline int
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_gcry_ctz64(u64 x)
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{
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#if defined (HAVE_BUILTIN_CTZL) && SIZEOF_UNSIGNED_LONG >= 8
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return x ? __builtin_ctzl (x) : 8 * sizeof (x);
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#elif defined (HAVE_BUILTIN_CTZ) && SIZEOF_UNSIGNED_INT >= 8
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#warning hello
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return x ? __builtin_ctz (x) : 8 * sizeof (x);
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#else
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if ((x & 0xffffffff))
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return _gcry_ctz (x);
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else
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return 32 + _gcry_ctz (x >> 32);
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#endif
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}
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#endif /*GCRYPT_BITHELP_H*/
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