mingw: implement getppid
[git/kusma.git] / compat / bswap.h
blob54756dbb05ba99ab1679f17a50f04c3f1cede8e6
1 /*
2 * Let's make sure we always have a sane definition for ntohl()/htonl().
3 * Some libraries define those as a function call, just to perform byte
4 * shifting, bringing significant overhead to what should be a simple
5 * operation.
6 */
8 /*
9 * Default version that the compiler ought to optimize properly with
10 * constant values.
12 static inline uint32_t default_swab32(uint32_t val)
14 return (((val & 0xff000000) >> 24) |
15 ((val & 0x00ff0000) >> 8) |
16 ((val & 0x0000ff00) << 8) |
17 ((val & 0x000000ff) << 24));
20 #undef bswap32
22 #if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
24 #define bswap32(x) ({ \
25 uint32_t __res; \
26 if (__builtin_constant_p(x)) { \
27 __res = default_swab32(x); \
28 } else { \
29 __asm__("bswap %0" : "=r" (__res) : "0" ((uint32_t)(x))); \
30 } \
31 __res; })
33 #elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
35 #include <stdlib.h>
37 #define bswap32(x) _byteswap_ulong(x)
39 #endif
41 #ifdef bswap32
43 #undef ntohl
44 #undef htonl
45 #define ntohl(x) bswap32(x)
46 #define htonl(x) bswap32(x)
48 #endif