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| author | Akinobu Mita <akinobu.mita@gmail.com> | 2012-03-23 15:02:14 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-23 16:58:35 -0700 |
| commit | f43804bf5f9ae1e60077c5f22aee5fdfe4f09837 (patch) | |
| tree | 61e2dcaef0ab774d5cd68a89859f569d54fa7f78 /lib/prio_tree.c | |
| parent | a403d930c58eb8448f81fa90c125ac36dc8ef89d (diff) | |
string: memchr_inv() speed improvements
- Generate a 64-bit pattern more efficiently
memchr_inv needs to generate a 64-bit pattern filled with a target
character. The operation can be done by more efficient way.
- Don't call the slow check_bytes() if the memory area is 64-bit aligned
memchr_inv compares contiguous 64-bit words with the 64-bit pattern as
much as possible. The outside of the region is checked by check_bytes()
that scans for each byte. Unfortunately, the first 64-bit word is
unexpectedly scanned by check_bytes() even if the memory area is aligned
to a 64-bit boundary.
Both changes were originally suggested by Eric Dumazet.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/prio_tree.c')
0 files changed, 0 insertions, 0 deletions