diff options
Diffstat (limited to 'bits/byteswap.h')
| -rw-r--r-- | bits/byteswap.h | 101 |
1 files changed, 34 insertions, 67 deletions
diff --git a/bits/byteswap.h b/bits/byteswap.h index f99a6a4a27..23974e9083 100644 --- a/bits/byteswap.h +++ b/bits/byteswap.h @@ -1,4 +1,4 @@ -/* Macros to swap the order of bytes in integer values. +/* Macros and inline functions to swap the order of bytes in integer values. Copyright (C) 1997-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. @@ -26,87 +26,54 @@ #include <features.h> #include <bits/types.h> -/* Swap bytes in 16 bit value. */ -#define __bswap_constant_16(x) \ - ((unsigned short int)((((x) >> 8) & 0xffu) | (((x) & 0xffu) << 8))) +/* Swap bytes in 16-bit value. */ +#define __bswap_constant_16(x) \ + ((__uint16_t) ((((x) >> 8) & 0xff) | (((x) & 0xff) << 8))) -/* Get __bswap_16. */ -#include <bits/byteswap-16.h> +static __inline __uint16_t +__bswap_16 (__uint16_t __bsx) +{ +#if __GNUC_PREREQ (4, 8) + return __builtin_bswap16 (__bsx); +#else + 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)) +/* Swap bytes in 32-bit value. */ +#define __bswap_constant_32(x) \ + ((((x) & 0xff000000u) >> 24) | (((x) & 0x00ff0000u) >> 8) \ + | (((x) & 0x0000ff00u) << 8) | (((x) & 0x000000ffu) << 24)) -#ifdef __GNUC__ -# if __GNUC_PREREQ (4, 3) -static __inline unsigned int -__bswap_32 (unsigned int __bsx) +static __inline __uint32_t +__bswap_32 (__uint32_t __bsx) { +#if __GNUC_PREREQ (4, 3) return __builtin_bswap32 (__bsx); -} -# else -# define __bswap_32(x) \ - (__extension__ \ - ({ unsigned int __bsx = (x); __bswap_constant_32 (__bsx); })) -# endif #else -static __inline unsigned int -__bswap_32 (unsigned int __bsx) -{ return __bswap_constant_32 (__bsx); -} #endif +} -/* Swap bytes in 64 bit value. */ -#if __GNUC_PREREQ (2, 0) -# define __bswap_constant_64(x) \ - (__extension__ ((((x) & 0xff00000000000000ull) >> 56) \ - | (((x) & 0x00ff000000000000ull) >> 40) \ - | (((x) & 0x0000ff0000000000ull) >> 24) \ - | (((x) & 0x000000ff00000000ull) >> 8) \ - | (((x) & 0x00000000ff000000ull) << 8) \ - | (((x) & 0x0000000000ff0000ull) << 24) \ - | (((x) & 0x000000000000ff00ull) << 40) \ - | (((x) & 0x00000000000000ffull) << 56))) +/* 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 __GNUC_PREREQ (4, 3) -static __inline __uint64_t +__extension__ static __inline __uint64_t __bswap_64 (__uint64_t __bsx) { +#if __GNUC_PREREQ (4, 3) return __builtin_bswap64 (__bsx); -} -# else -# define __bswap_64(x) \ - (__extension__ \ - ({ union { __extension__ __uint64_t __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 #else -# 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)) - -static __inline __uint64_t -__bswap_64 (__uint64_t __bsx) -{ return __bswap_constant_64 (__bsx); -} #endif +} #endif /* _BITS_BYTESWAP_H */ |