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| author | Quincey Koziol <koziol@hdfgroup.org> | 2006-03-11 22:04:30 (GMT) |
|---|---|---|
| committer | Quincey Koziol <koziol@hdfgroup.org> | 2006-03-11 22:04:30 (GMT) |
| commit | 2501750f5e1ef612f8ab3d7112c0f29381be6466 (patch) | |
| tree | 5dd25d1c2c318ee97e9806cc10df4027347a1c49 /src/H5private.h | |
| parent | 6af9839f16b6dd96e1e961f527cbbce31f05b33f (diff) | |
| download | hdf5-2501750f5e1ef612f8ab3d7112c0f29381be6466.zip hdf5-2501750f5e1ef612f8ab3d7112c0f29381be6466.tar.gz hdf5-2501750f5e1ef612f8ab3d7112c0f29381be6466.tar.bz2 | |
[svn-r12081] Purpose:
New feature
Description:
Update "power of two" macro and add "general" log2() routine.
Platforms tested:
FreeBSD 4.11 (sleipnir)
Too minor to require h5committest
Diffstat (limited to 'src/H5private.h')
| -rw-r--r-- | src/H5private.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/H5private.h b/src/H5private.h index 531b3dd..5d1494f 100644 --- a/src/H5private.h +++ b/src/H5private.h @@ -326,7 +326,8 @@ #endif /* test for number that is a power of 2 */ -# define POWER_OF_TWO(n) ((((n) - 1) & (n)) == 0 && (n) > 0) +/* (from: http://graphics.stanford.edu/~seander/bithacks.html#DetermineIfPowerOf2) */ +# define POWER_OF_TWO(n) (!(n & (n - 1)) && n) /* * HDF Boolean type. |