diff options
Diffstat (limited to 'libc/sysdeps/linux/common/bits/byteswap-common.h')
| -rw-r--r-- | libc/sysdeps/linux/common/bits/byteswap-common.h | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/common/bits/byteswap-common.h b/libc/sysdeps/linux/common/bits/byteswap-common.h new file mode 100644 index 000000000..8586ed008 --- /dev/null +++ b/libc/sysdeps/linux/common/bits/byteswap-common.h @@ -0,0 +1,108 @@ +/* Macros to swap the order of bytes in integer values. + Copyright (C) 1997,1998,2000,2001,2002,2005 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 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, 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." +#endif + +#ifndef _BITS_BYTESWAP_H +#define _BITS_BYTESWAP_H 1 + +/* Swap bytes in 16 bit value. */ +#define __bswap_constant_16(x) \ + ((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8)) + +#ifndef __bswap_non_constant_16 +# define __bswap_non_constant_16(x) __bswap_constant_16(x) +#endif +#ifdef __GNUC__ +# define __bswap_16(x) \ + (__extension__ \ + ({ unsigned short int __bsv, __bsx = (x); \ + if (__builtin_constant_p (__bsx)) \ + __bsv = __bswap_constant_16 (__bsx); \ + else \ + __bsv = __bswap_non_constant_16 (__bsx); \ + __bsv; })) +#else +static __inline unsigned short int +__bswap_16 (unsigned short int __bsx) +{ + return __bswap_constant_16 (__bsx); +} +#endif + +/* Swap bytes in 32 bit value. */ +#define __bswap_constant_32(x) \ + ((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >> 8) | \ + (((x) & 0x0000ff00u) << 8) | (((x) & 0x000000ffu) << 24)) + +#ifndef __bswap_non_constant_32 +# define __bswap_non_constant_32(x) __bswap_constant_32(x) +#endif +#ifdef __GNUC__ +# define __bswap_32(x) \ + (__extension__ \ + ({ unsigned int __bsv, __bsx = (x); \ + if (__builtin_constant_p (__bsx)) \ + __bsv = __bswap_constant_32 (__bsx); \ + else \ + __bsv = __bswap_non_constant_32 (__bsx); \ + __bsv; })) +#else +static __inline unsigned int +__bswap_32 (unsigned int __bsx) +{ + return __bswap_constant_32 (__bsx); +} +#endif + +#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)) + +# ifndef __bswap_non_constant_64 +# define __bswap_non_constant_64(x) \ + (__extension__ \ + ({ union { __extension__ unsigned long long int __ll; \ + unsigned int __l[2]; } __w, __r; \ + __w.__ll = (x); \ + __r.__l[0] = __bswap_non_constant_32 (__w.__l[1]); \ + __r.__l[1] = __bswap_non_constant_32 (__w.__l[0]); \ + __r.__ll; })) +# endif +# define __bswap_64(x) \ + (__extension__ \ + ({ __extension__ unsigned long long int __ll; \ + if (__builtin_constant_p (x)) \ + __ll = __bswap_constant_64 (x); \ + else \ + __ll = __bswap_non_constant_64 (x); \ + __ll; })) +#endif + +#endif /* _BITS_BYTESWAP_H */ |