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/* bitrotate.h - Rotate bits in integers
Copyright (C) 2008-2011 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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