139 lines
4.5 KiB
C
139 lines
4.5 KiB
C
/* bitrotate.h - Rotate bits in integers
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Copyright (C) 2008-2020 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program 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 General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>. */
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/* Written by Simon Josefsson <simon@josefsson.org>, 2008. */
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#ifndef _GL_BITROTATE_H
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#define _GL_BITROTATE_H
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#include <limits.h>
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#include <stdint.h>
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#include <sys/types.h>
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#ifndef _GL_INLINE_HEADER_BEGIN
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#error "Please include config.h first."
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#endif
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_GL_INLINE_HEADER_BEGIN
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#ifndef BITROTATE_INLINE
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# define BITROTATE_INLINE _GL_INLINE
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#endif
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#ifdef UINT64_MAX
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/* Given an unsigned 64-bit argument X, return the value corresponding
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to rotating the bits N steps to the left. N must be between 1 and
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63 inclusive. */
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BITROTATE_INLINE uint64_t
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rotl64 (uint64_t x, int n)
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{
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return ((x << n) | (x >> (64 - n))) & UINT64_MAX;
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}
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/* Given an unsigned 64-bit argument X, return the value corresponding
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to rotating the bits N steps to the right. N must be between 1 to
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63 inclusive.*/
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BITROTATE_INLINE uint64_t
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rotr64 (uint64_t x, int n)
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{
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return ((x >> n) | (x << (64 - n))) & UINT64_MAX;
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}
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#endif
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/* Given an unsigned 32-bit argument X, return the value corresponding
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to rotating the bits N steps to the left. N must be between 1 and
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31 inclusive. */
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BITROTATE_INLINE uint32_t
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rotl32 (uint32_t x, int n)
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{
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return ((x << n) | (x >> (32 - n))) & UINT32_MAX;
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}
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/* Given an unsigned 32-bit argument X, return the value corresponding
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to rotating the bits N steps to the right. N must be between 1 to
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31 inclusive.*/
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BITROTATE_INLINE uint32_t
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rotr32 (uint32_t x, int n)
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{
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return ((x >> n) | (x << (32 - n))) & UINT32_MAX;
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}
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/* Given a size_t argument X, return the value corresponding
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to rotating the bits N steps to the left. N must be between 1 and
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(CHAR_BIT * sizeof (size_t) - 1) inclusive. */
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BITROTATE_INLINE size_t
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rotl_sz (size_t x, int n)
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{
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return ((x << n) | (x >> ((CHAR_BIT * sizeof x) - n))) & SIZE_MAX;
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}
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/* Given a size_t argument X, return the value corresponding
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to rotating the bits N steps to the right. N must be between 1 to
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(CHAR_BIT * sizeof (size_t) - 1) inclusive. */
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BITROTATE_INLINE size_t
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rotr_sz (size_t x, int n)
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{
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return ((x >> n) | (x << ((CHAR_BIT * sizeof x) - n))) & SIZE_MAX;
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}
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/* Given an unsigned 16-bit argument X, return the value corresponding
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to rotating the bits N steps to the left. N must be between 1 to
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15 inclusive, but on most relevant targets N can also be 0 and 16
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because 'int' is at least 32 bits and the arguments must widen
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before shifting. */
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BITROTATE_INLINE uint16_t
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rotl16 (uint16_t x, int n)
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{
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return (((unsigned int) x << n) | ((unsigned int) x >> (16 - n)))
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& UINT16_MAX;
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}
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/* Given an unsigned 16-bit argument X, return the value corresponding
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to rotating the bits N steps to the right. N must be in 1 to 15
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inclusive, but on most relevant targets N can also be 0 and 16
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because 'int' is at least 32 bits and the arguments must widen
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before shifting. */
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BITROTATE_INLINE uint16_t
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rotr16 (uint16_t x, int n)
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{
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return (((unsigned int) x >> n) | ((unsigned int) x << (16 - n)))
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& UINT16_MAX;
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}
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/* Given an unsigned 8-bit argument X, return the value corresponding
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to rotating the bits N steps to the left. N must be between 1 to 7
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inclusive, but on most relevant targets N can also be 0 and 8
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because 'int' is at least 32 bits and the arguments must widen
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before shifting. */
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BITROTATE_INLINE uint8_t
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rotl8 (uint8_t x, int n)
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{
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return (((unsigned int) x << n) | ((unsigned int) x >> (8 - n))) & UINT8_MAX;
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}
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/* Given an unsigned 8-bit argument X, return the value corresponding
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to rotating the bits N steps to the right. N must be in 1 to 7
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inclusive, but on most relevant targets N can also be 0 and 8
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because 'int' is at least 32 bits and the arguments must widen
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before shifting. */
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BITROTATE_INLINE uint8_t
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rotr8 (uint8_t x, int n)
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{
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return (((unsigned int) x >> n) | ((unsigned int) x << (8 - n))) & UINT8_MAX;
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}
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_GL_INLINE_HEADER_END
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#endif /* _GL_BITROTATE_H */
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