[patch 3/N] std::regex refactoring - _Executor DFS / BFS

[Tim Shen]

On Tue, Apr 29, 2014 at 6:17 AM, Jonathan Wakely <jwakely@redhat.com> wrote:
> This runs much faster on trunk than with 4.9.0, so we might want to
> backport your recent patches to the gcc-4_9-branch.

It's faster but nothing to do with optimization. It's because my first
patch set the DFS approach by default, which is faster in common case
but has bad worst case performance. Try your testcase and
regex_match("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", regex("(a*){30}"))
with/without defining _GLIBCXX_REGEX_USE_THOMPSON_NFA in the trunk
version.


-- 
Regards,
Tim Shen