/* bitrotate.h - Rotate bits in integers | |

Copyright (C) 2008-2012 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> | |

_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 */ |