[Patch] Regex bracket matcher cache optimization

[Tim Shen]

The data structure _BracketMatcher (storing regex like [123a-z]) could
be quite slow mainly because of regex_traits. So a result of cache for
small range of inputs (char) sounds reasonable. It iterates all 256
inputs and calculate them at regex compile time.

Booted and tested under -m64 and -m32.

Thanks!


-- 
Regards,
Tim Shen
-------------- next part --------------
A non-text attachment was scrubbed...
Name: a.patch
Type: text/x-patch
Size: 21434 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20140104/d5034ea2/attachment.bin>