http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55135
--- Comment #28 from Steven Bosscher <steven at gcc dot gnu.org> 2013-03-06 12:18:01 UTC --- (In reply to comment #22) > Posted for discussion here: > http://gcc.gnu.org/ml/gcc-patches/2013-03/msg00193.html OT: Another trivial speed-up for bitmaps used as regsets (and probably in general) is to look at head->first if head->current is not the element containing the sought bit, and *not* update head->current if head->first is the right element. This speeds up regsets because a common access pattern is to look at sets containing both pseudos and hardregs, and on most targets all hardregs are in head->first. Not updating head->current preserves a pointer to the latest accessed pseudos. I'll implement this idea and come back with some timings.
