http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52459
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Summary|[x86] loop vectorization |[x86] loop performance very |performance very bad (worse |bad (worse than -O0) when |than -O0) when using sse4.2 |using sse4.2 popcnt |popcnt | --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-03-02 07:19:49 UTC --- This has nothing to do with the vectorizer but rather PPRE.