diff options
| author | Laurent Bercot <ska-skaware@skarnet.org> | 2017-10-18 16:13:24 +0000 |
|---|---|---|
| committer | Laurent Bercot <ska-skaware@skarnet.org> | 2017-10-18 16:13:24 +0000 |
| commit | 45923c08b00ccdfd888caf6d2b555a137c563988 (patch) | |
| tree | 5dc167cf4b8e3ff372f59ca9fb6ba0940387c83c /src/libstddjb/uint64_bswap.c | |
| parent | 62a04cdd0b6811c07bbafae37fe906a36fa800b1 (diff) | |
| download | skalibs-45923c08b00ccdfd888caf6d2b555a137c563988.tar.xz | |
Better packing / unpacking code
Godbolted for x86_64 with gcc and clang.
Diffstat (limited to 'src/libstddjb/uint64_bswap.c')
| -rw-r--r-- | src/libstddjb/uint64_bswap.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/src/libstddjb/uint64_bswap.c b/src/libstddjb/uint64_bswap.c new file mode 100644 index 0000000..3dfaf18 --- /dev/null +++ b/src/libstddjb/uint64_bswap.c @@ -0,0 +1,16 @@ +/* ISC license. */ + +#include <skalibs/uint64.h> + +uint64_t uint64_bswap (uint64_t a) +{ + return + (a & 0x00000000000000ffull) << 56 | + (a & 0x000000000000ff00ull) << 40 | + (a & 0x0000000000ff0000ull) << 24 | + (a & 0x00000000ff000000ull) << 8 | + (a & 0x000000ff00000000ull) >> 8 | + (a & 0x0000ff0000000000ull) >> 24 | + (a & 0x00ff000000000000ull) >> 40 | + (a & 0xff00000000000000ull) >> 56 ; +} |