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| author | Neil Roberts <neil@linux.intel.com> | 2011-11-01 13:10:59 +0000 |
|---|---|---|
| committer | Neil Roberts <neil@linux.intel.com> | 2011-11-16 16:32:11 +0000 |
| commit | 037c0aa88cb8eb74f21ce24c80467b909028d2f6 (patch) | |
| tree | 6113491fed1b96315e70b053e8ec8f25970b57cc /cogl/cogl-util.c | |
| parent | 436a7a45da0298f72d5b839601c60a5d23108a8a (diff) | |
| download | cogl-037c0aa88cb8eb74f21ce24c80467b909028d2f6.tar.gz | |
Move POPCOUNTL to cogl-util
This moves the POPCOUNTL macro from cogl-winsys-glx to cogl-util and
renames it to _cogl_util_popcountl so that it can be used in more
places. The fallback function for when the GCC builtin is not
available has been replaced with an 8-bit lookup table because the
HAKMEM implementation doesn't look like it would work when longs are
64-bit so it's not suitable for a general purpose function on 64-bit
architectures. Some of the pages regarding population counts seem to
suggest that using a lookup table is the fastest method anyway.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
Diffstat (limited to 'cogl/cogl-util.c')
| -rw-r--r-- | cogl/cogl-util.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/cogl/cogl-util.c b/cogl/cogl-util.c index 1cb38143..487a762c 100644 --- a/cogl/cogl-util.c +++ b/cogl/cogl-util.c @@ -100,3 +100,23 @@ _cogl_util_ffsl_wrapper (long int num) } #endif /* COGL_UTIL_HAVE_BUILTIN_FFSL */ + +#ifndef COGL_UTIL_HAVE_BUILTIN_POPCOUNTL + +const unsigned char +_cogl_util_popcount_table[256] = + { + 0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3, 2, 3, 3, 4, + 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, + 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 1, 2, 2, 3, 2, 3, 3, 4, + 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, + 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, + 4, 5, 5, 6, 5, 6, 6, 7, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, + 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2, 3, 3, 4, 3, 4, 4, 5, + 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, + 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6, + 4, 5, 5, 6, 5, 6, 6, 7, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, + 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6, 7, 7, 8 + }; + +#endif /* COGL_UTIL_HAVE_BUILTIN_POPCOUNTL */ |