/* bitrotate.h - Rotate bits in integers

   Copyright (C) 2008-2020 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify

   it under the terms of the GNU Lesser General Public License as published by

   the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser 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 (((unsigned int) x << n) | ((unsigned int) 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 (((unsigned int) x >> n) | ((unsigned int) 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 (((unsigned int) x << n) | ((unsigned int) 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 (((unsigned int) x >> n) | ((unsigned int) x << (8 - n))) & UINT8_MAX;

}

_GL_INLINE_HEADER_END

#endif /* _GL_BITROTATE_H */