+
−/* bitrotate.h - Rotate bits in integers
+
−   Copyright (C) 2008-2013 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 */