diff options
Diffstat (limited to 'libc/sysdeps/linux/i386/bits/byteswap.h')
| -rw-r--r-- | libc/sysdeps/linux/i386/bits/byteswap.h | 39 |
1 files changed, 27 insertions, 12 deletions
diff --git a/libc/sysdeps/linux/i386/bits/byteswap.h b/libc/sysdeps/linux/i386/bits/byteswap.h index a1ba6b874..c76b0814d 100644 --- a/libc/sysdeps/linux/i386/bits/byteswap.h +++ b/libc/sysdeps/linux/i386/bits/byteswap.h @@ -1,21 +1,21 @@ /* Macros to swap the order of bytes in integer values. - Copyright (C) 1997, 1998 Free Software Foundation, Inc. + Copyright (C) 1997, 1998, 2000 Free Software Foundation, Inc. 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 Library General Public License as - published by the Free Software Foundation; either version 2 of the - License, or (at your option) any later version. + 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 - Library General Public License for more details. + Lesser General Public License for more details. - You should have received a copy of the GNU Library General Public - License along with the GNU C Library; see the file COPYING.LIB. If not, - write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, - Boston, MA 02111-1307, USA. */ + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ #if !defined _BYTESWAP_H && !defined _NETINET_IN_H # error "Never use <bits/byteswap.h> directly; include <byteswap.h> instead." @@ -84,12 +84,27 @@ #if defined __GNUC__ && __GNUC__ >= 2 /* Swap bytes in 64 bit value. */ +#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)) + # define __bswap_64(x) \ (__extension__ \ ({ union { __extension__ 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]); \ + if (__builtin_constant_p (x)) \ + __r.__ll = __bswap_constant_64 (x); \ + else \ + { \ + __w.__ll = (x); \ + __r.__l[0] = __bswap_32 (__w.__l[1]); \ + __r.__l[1] = __bswap_32 (__w.__l[0]); \ + } \ __r.__ll; })) #endif |