l4/pkg/l4re-core/uclibc/lib/contrib/uclibc/libc/sysdeps/linux/x86_64/bits/byteswap.h

   1 /* Macros to swap the order of bytes in integer values.
   2    Copyright (C) 1997, 1998, 2000, 2002, 2003 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _ASM_BITS_BYTESWAP_H
  20 #define _ASM_BITS_BYTESWAP_H 1
  21
  22 #include <bits/wordsize.h>
  23
  24 #define __bswap_non_constant_16(x) \
  25      (__extension__                                                           \
  26       ({ register unsigned short int __v;                                     \
  27          __asm__ ("rorw $8, %w0"                                              \
  28                   : "=r" (__v)                                                \
  29                   : "0" (x)                                                   \
  30                   : "cc");                                                    \
  31          __v; }))
  32
  33 #if __WORDSIZE == 64 || (defined __i486__ || defined __pentium__              \
  34                      || defined __pentiumpro__ || defined __pentium4__        \
  35                      || defined __k8__ || defined __athlon__                  \
  36                      || defined __k6__)
  37 /* To swap the bytes in a word the i486 processors and up provide the
  38    `bswap' opcode.  On i386 we have to use three instructions.  */
  39 # define __bswap_non_constant_32(x) \
  40      (__extension__                                                           \
  41       ({ register unsigned int __v;                                           \
  42          __asm__ ("bswap %0" : "=r" (__v) : "0" (x));                         \
  43          __v; }))
  44 #else
  45 # define __bswap_non_constant_32(x) \
  46      (__extension__                                                           \
  47       ({ register unsigned int __v;                                           \
  48          __asm__ ("rorw $8, %w0;"                                             \
  49                   "rorl $16, %0;"                                             \
  50                   "rorw $8, %w0"                                              \
  51                   : "=r" (__v)                                                \
  52                   : "0" (x)                                                   \
  53                   : "cc");                                                    \
  54          __v; }))
  55 #endif
  56
  57 #if __WORDSIZE == 64
  58 # define __bswap_non_constant_64(x) \
  59      (__extension__                                                           \
  60       ({ register unsigned long __v;                                          \
  61          __asm__ ("bswap %q0" : "=r" (__v) : "0" (x));                        \
  62          __v; }))
  63 #endif
  64
  65 #endif
  66
  67 #include <bits/byteswap-common.h>