glibc/sysdeps/s390/bits/byteswap.h

/* Macros to swap the order of bytes in integer values.  s390 version.
   Copyright (C) 2000-2017 Free Software Foundation, Inc.
   Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
   This file is part of the GNU C Library.

   The GNU C Library 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.

   The GNU C Library 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 the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#if !defined _BYTESWAP_H && !defined _NETINET_IN_H && !defined _ENDIAN_H
# error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead."
#endif

#include <bits/wordsize.h>

#ifndef _BITS_BYTESWAP_H
#define _BITS_BYTESWAP_H 1

#define __bswap_constant_16(x) \
	((unsigned short int) ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8)))

/* Get __bswap_16.  */
#include <bits/byteswap-16.h>

/* Swap bytes in 32 bit value.  */
#define __bswap_constant_32(x) \
     ((((x) & 0xff000000) >> 24) | (((x) & 0x00ff0000) >>  8) |		      \
      (((x) & 0x0000ff00) <<  8) | (((x) & 0x000000ff) << 24))

#if defined __GNUC__ && __GNUC__ >= 2
# if __WORDSIZE == 64
#  define __bswap_32(x) \
     (__extension__							      \
      ({ unsigned int __v, __x = (x);					      \
	 if (__builtin_constant_p (x))					      \
	   __v = __bswap_constant_32 (__x);				      \
	 else {								      \
	   unsigned int __tmp = (unsigned int) (__x);                         \
	   __asm__ __volatile__ (                                             \
	      "lrv   %0,%1"                                                   \
	      : "=&d" (__v) : "m" (__tmp));                                   \
	 }                                                                    \
	 __v; }))
# else
#  define __bswap_32(x) \
     (__extension__							      \
      ({ unsigned int __v, __x = (x);					      \
	 if (__builtin_constant_p (x))					      \
	   __v = __bswap_constant_32 (__x);				      \
	 else {								      \
	   unsigned int __tmp = (unsigned int) (__x);                         \
	   __asm__ __volatile__ (                                             \
	      "la    1,%1\n"                                                  \
	      "icm   %0,8,3(1)\n"                                             \
	      "icm   %0,4,2(1)\n"                                             \
	      "icm   %0,2,1(1)\n"                                             \
	      "ic    %0,0(1)"                                                 \
	      : "=&d" (__v) : "m" (__tmp) : "1");                             \
	 }                                                                    \
	 __v; }))
# endif
#else
static __inline unsigned int
__bswap_32 (unsigned int __bsx)
{
  return __bswap_constant_32 (__bsx);
}
#endif

/* Swap bytes in 64 bit value.  */
#if defined __GNUC__ && __GNUC__ >= 2
# define __bswap_constant_64(x) \
     (__extension__ ((((x) & 0xff00000000000000ul) >> 56)		      \
		     | (((x) & 0x00ff000000000000ul) >>  40)		      \
		     | (((x) & 0x0000ff0000000000ul) >> 24)		      \
		     | (((x) & 0x000000ff00000000ul) >> 8)		      \
		     | (((x) & 0x00000000ff000000ul) << 8)		      \
		     | (((x) & 0x0000000000ff0000ul) << 24)		      \
		     | (((x) & 0x000000000000ff00ul) << 40)		      \
		     | (((x) & 0x00000000000000fful) << 56)))

# if __WORDSIZE == 64
#  define __bswap_64(x) \
     (__extension__							      \
      ({ unsigned long __w, __x = (x);					      \
	 if (__builtin_constant_p (x))					      \
	   __w = __bswap_constant_64 (__x);				      \
	 else {								      \
	   unsigned long __tmp = (unsigned long) (__x);                       \
	   __asm__ __volatile__ (                                             \
	      "lrvg  %0,%1"                                                   \
	      : "=&d" (__w) : "m" (__tmp));                                   \
	 }                                                                    \
	 __w; }))
# else
#  define __bswap_64(x) \
     __extension__					\
       ({ union { unsigned long long int __ll;		\
		  unsigned long int __l[2]; } __w, __r;	\
	  __w.__ll = (x);				\
	  __r.__l[0] = __bswap_32 (__w.__l[1]);		\
	  __r.__l[1] = __bswap_32 (__w.__l[0]);		\
	  __r.__ll; })
# endif
#else
# define __bswap_constant_64(x) \
     ((((x) & 0xff00000000000000ull) >> 56)				      \
      | (((x) & 0x00ff000000000000ull) >> 40)				      \
      | (((x) & 0x0000ff0000000000ull) >> 24)				      \
      | (((x) & 0x000000ff00000000ull) >> 8)				      \
      | (((x) & 0x00000000ff000000ull) << 8)				      \
      | (((x) & 0x0000000000ff0000ull) << 24)				      \
      | (((x) & 0x000000000000ff00ull) << 40)				      \
      | (((x) & 0x00000000000000ffull) << 56))

__extension__
static __inline unsigned long long int
__bswap_64 (unsigned long long int __bsx)
{
  return __bswap_constant_64 (__bsx);
}
#endif

#endif /* _BITS_BYTESWAP_H */