completion: fix completion after 'git --option <TAB>'
[git/jnareb-git.git] / compat / bswap.h
blob5061214f73d2d51cfd1d49b97b4e69be913928bd
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 git_bswap32
25 static inline uint32_t git_bswap32(uint32_t x)
27 uint32_t result;
28 if (__builtin_constant_p(x))
29 result = default_swab32(x);
30 else
31 __asm__("bswap %0" : "=r" (result) : "0" (x));
32 return result;
35 #elif defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_X64))
37 #include <stdlib.h>
39 #define bswap32(x) _byteswap_ulong(x)
41 #endif
43 #ifdef bswap32
45 #undef ntohl
46 #undef htonl
47 #define ntohl(x) bswap32(x)
48 #define htonl(x) bswap32(x)
50 #endif