diff options
Diffstat (limited to 'libc/sysdeps/linux/x86_64/bits')
| -rw-r--r-- | libc/sysdeps/linux/x86_64/bits/byteswap.h | 127 |
1 files changed, 31 insertions, 96 deletions
diff --git a/libc/sysdeps/linux/x86_64/bits/byteswap.h b/libc/sysdeps/linux/x86_64/bits/byteswap.h index e1c861c75..a9cf23d75 100644 --- a/libc/sysdeps/linux/x86_64/bits/byteswap.h +++ b/libc/sysdeps/linux/x86_64/bits/byteswap.h @@ -17,117 +17,52 @@ 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 +#ifndef _ASM_BITS_BYTESWAP_H +#define _ASM_BITS_BYTESWAP_H 1 #include <bits/wordsize.h> -/* Swap bytes in 16 bit value. */ -#define __bswap_constant_16(x) \ - ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8)) - -#if defined __GNUC__ && __GNUC__ >= 2 -# define __bswap_16(x) \ +#define __bswap_non_constant_16(x) \ (__extension__ \ - ({ register unsigned short int __v, __x = (x); \ - if (__builtin_constant_p (__x)) \ - __v = __bswap_constant_16 (__x); \ - else \ - __asm__ ("rorw $8, %w0" \ - : "=r" (__v) \ - : "0" (__x) \ - : "cc"); \ + ({ register unsigned short int __v; \ + __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 = (x); __bswap_constant_16 (__x); })) -#endif - - -/* 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 || (defined __i486__ || defined __pentium__ \ - || defined __pentiumpro__ || defined __pentium4__ \ - || defined __k8__ || defined __athlon__ \ - || defined __k6__) +#if __WORDSIZE == 64 || (defined __i486__ || defined __pentium__ \ + || defined __pentiumpro__ || defined __pentium4__ \ + || defined __k8__ || defined __athlon__ \ + || defined __k6__) /* To swap the bytes in a word the i486 processors and up provide the `bswap' opcode. On i386 we have to use three instructions. */ -# define __bswap_32(x) \ +# define __bswap_non_constant_32(x) \ (__extension__ \ - ({ register unsigned int __v, __x = (x); \ - if (__builtin_constant_p (__x)) \ - __v = __bswap_constant_32 (__x); \ - else \ - __asm__ ("bswap %0" : "=r" (__v) : "0" (__x)); \ + ({ register unsigned int __v; \ + __asm__ ("bswap %0" : "=r" (__v) : "0" (x)); \ __v; })) -# else -# define __bswap_32(x) \ - (__extension__ \ - ({ register unsigned int __v, __x = (x); \ - if (__builtin_constant_p (__x)) \ - __v = __bswap_constant_32 (__x); \ - else \ - __asm__ ("rorw $8, %w0;" \ - "rorl $16, %0;" \ - "rorw $8, %w0" \ - : "=r" (__v) \ - : "0" (__x) \ - : "cc"); \ - __v; })) -# endif #else -# define __bswap_32(x) \ +# define __bswap_non_constant_32(x) \ (__extension__ \ - ({ register unsigned int __x = (x); __bswap_constant_32 (__x); })) + ({ register unsigned int __v; \ + __asm__ ("rorw $8, %w0;" \ + "rorl $16, %0;" \ + "rorw $8, %w0" \ + : "=r" (__v) \ + : "0" (x) \ + : "cc"); \ + __v; })) #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)) - -# if __WORDSIZE == 64 -# define __bswap_64(x) \ +#if __WORDSIZE == 64 +# define __bswap_non_constant_64(x) \ (__extension__ \ - ({ register unsigned long __v, __x = (x); \ - if (__builtin_constant_p (__x)) \ - __v = __bswap_constant_64 (__x); \ - else \ - __asm__ ("bswap %q0" : "=r" (__v) : "0" (__x)); \ + ({ register unsigned long __v; \ + __asm__ ("bswap %q0" : "=r" (__v) : "0" (x)); \ __v; })) -# else -# define __bswap_64(x) \ - (__extension__ \ - ({ union { __extension__ unsigned long long int __ll; \ - unsigned int __l[2]; } __w, __r; \ - 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 #endif -#endif /* _BITS_BYTESWAP_H */ +#endif + +#include <bits/byteswap-common.h> |