/* bitrotate.h - Rotate bits in integers Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ /* Written by Simon Josefsson <simon@josefsson.org>, 2008. */ #ifndef _GL_BITROTATE_H #define _GL_BITROTATE_H #include <limits.h> #include <stdint.h> #include <sys/types.h> #ifdef UINT64_MAX /* Given an unsigned 64-bit argument X, return the value corresponding to rotating the bits N steps to the left. N must be between 1 and 63 inclusive. */ static inline uint64_t rotl64 (uint64_t x, int n) { return ((x << n) | (x >> (64 - n))) & UINT64_MAX; } /* Given an unsigned 64-bit argument X, return the value corresponding to rotating the bits N steps to the right. N must be between 1 to 63 inclusive.*/ static inline uint64_t rotr64 (uint64_t x, int n) { return ((x >> n) | (x << (64 - n))) & UINT64_MAX; } #endif /* Given an unsigned 32-bit argument X, return the value corresponding to rotating the bits N steps to the left. N must be between 1 and 31 inclusive. */ static inline uint32_t rotl32 (uint32_t x, int n) { return ((x << n) | (x >> (32 - n))) & UINT32_MAX; } /* Given an unsigned 32-bit argument X, return the value corresponding to rotating the bits N steps to the right. N must be between 1 to 31 inclusive.*/ static inline uint32_t rotr32 (uint32_t x, int n) { return ((x >> n) | (x << (32 - n))) & UINT32_MAX; } /* Given a size_t argument X, return the value corresponding to rotating the bits N steps to the left. N must be between 1 and (CHAR_BIT * sizeof (size_t) - 1) inclusive. */ static inline size_t rotl_sz (size_t x, int n) { return ((x << n) | (x >> ((CHAR_BIT * sizeof x) - n))) & SIZE_MAX; } /* Given a size_t argument X, return the value corresponding to rotating the bits N steps to the right. N must be between 1 to (CHAR_BIT * sizeof (size_t) - 1) inclusive. */ static inline size_t rotr_sz (size_t x, int n) { return ((x >> n) | (x << ((CHAR_BIT * sizeof x) - n))) & SIZE_MAX; } /* Given an unsigned 16-bit argument X, return the value corresponding to rotating the bits N steps to the left. N must be between 1 to 15 inclusive, but on most relevant targets N can also be 0 and 16 because 'int' is at least 32 bits and the arguments must widen before shifting. */ static inline uint16_t rotl16 (uint16_t x, int n) { return ((x << n) | (x >> (16 - n))) & UINT16_MAX; } /* Given an unsigned 16-bit argument X, return the value corresponding to rotating the bits N steps to the right. N must be in 1 to 15 inclusive, but on most relevant targets N can also be 0 and 16 because 'int' is at least 32 bits and the arguments must widen before shifting. */ static inline uint16_t rotr16 (uint16_t x, int n) { return ((x >> n) | (x << (16 - n))) & UINT16_MAX; } /* Given an unsigned 8-bit argument X, return the value corresponding to rotating the bits N steps to the left. N must be between 1 to 7 inclusive, but on most relevant targets N can also be 0 and 8 because 'int' is at least 32 bits and the arguments must widen before shifting. */ static inline uint8_t rotl8 (uint8_t x, int n) { return ((x << n) | (x >> (8 - n))) & UINT8_MAX; } /* Given an unsigned 8-bit argument X, return the value corresponding to rotating the bits N steps to the right. N must be in 1 to 7 inclusive, but on most relevant targets N can also be 0 and 8 because 'int' is at least 32 bits and the arguments must widen before shifting. */ static inline uint8_t rotr8 (uint8_t x, int n) { return ((x >> n) | (x << (8 - n))) & UINT8_MAX; } #endif /* _GL_BITROTATE_H */

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