http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60828
--- Comment #3 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- I've looked at more profiles during the weekend and bitmaps always showed up on top. As Honza said on IRC, bitmaps go into obstacks and obstacks weren't optimized since the 80s. So it looks like tcmalloc just handles obstacks better than the stock glibc malloc.
