diff options
Diffstat (limited to 'sysdeps/x86_64/bits/byteswap-16.h')
-rw-r--r-- | sysdeps/x86_64/bits/byteswap-16.h | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/sysdeps/x86_64/bits/byteswap-16.h b/sysdeps/x86_64/bits/byteswap-16.h new file mode 100644 index 0000000000..584eb86b74 --- /dev/null +++ b/sysdeps/x86_64/bits/byteswap-16.h @@ -0,0 +1,49 @@ +/* Macros to swap the order of bytes in 16-bit integer values. + Copyright (C) 2012 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, see + <http://www.gnu.org/licenses/>. */ + +#ifndef _BITS_BYTESWAP_H +# error "Never use <bits/byteswap-16.h> directly; include <byteswap.h> instead." +#endif + +#ifdef __GNUC__ +# if __GNUC__ >= 2 +# define __bswap_16(x) \ + (__extension__ \ + ({ register unsigned short int __v, __x = (unsigned short int) (x); \ + if (__builtin_constant_p (__x)) \ + __v = __bswap_constant_16 (__x); \ + else \ + __asm__ ("rorw $8, %w0" \ + : "=r" (__v) \ + : "0" (__x) \ + : "cc"); \ + __v; })) +# else +/* This is better than nothing. */ +# define __bswap_16(x) \ + (__extension__ \ + ({ register unsigned short int __x = (unsigned short int) (x); \ + __bswap_constant_16 (__x); })) +# endif +#else +static __inline unsigned short int +__bswap_16 (unsigned short int __bsx) +{ + return __bswap_constant_16 (__bsx); +} +#endif |