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Diffstat (limited to 'gl/lib/bitrotate.h')
-rw-r--r-- | gl/lib/bitrotate.h | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/gl/lib/bitrotate.h b/gl/lib/bitrotate.h new file mode 100644 index 0000000..862331e --- /dev/null +++ b/gl/lib/bitrotate.h @@ -0,0 +1,136 @@ +/* bitrotate.h - Rotate bits in integers + Copyright (C) 2008-2019 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 <https://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> + +#ifndef _GL_INLINE_HEADER_BEGIN + #error "Please include config.h first." +#endif +_GL_INLINE_HEADER_BEGIN +#ifndef BITROTATE_INLINE +# define BITROTATE_INLINE _GL_INLINE +#endif + +#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. */ +BITROTATE_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.*/ +BITROTATE_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. */ +BITROTATE_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.*/ +BITROTATE_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. */ +BITROTATE_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. */ +BITROTATE_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. */ +BITROTATE_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. */ +BITROTATE_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. */ +BITROTATE_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. */ +BITROTATE_INLINE uint8_t +rotr8 (uint8_t x, int n) +{ + return ((x >> n) | (x << (8 - n))) & UINT8_MAX; +} + +_GL_INLINE_HEADER_END + +#endif /* _GL_BITROTATE_H */ |