On August 17, 2016 8:45:13 PM PDT, Borislav Petkov <[email protected]> wrote: >On Wed, Aug 17, 2016 at 03:29:04PM -0700, Huang, Ying wrote: >> branch-miss-rate decreased from ~0.30% to ~0.043%. >> >> So I guess there are some code alignment change, which caused >decreased >> branch miss rate. > >Hrrm, I still can't imagine how that would happen if the machine >supports POPCNT and we never call the __sw_hweight* variants. Or does >it? > >Can you paste /proc/cpuinfo from that Sandy Bridge-EP box? > >Thanks.
popcnt was introduced in Nehalem AFAIK, two generations before Sandy Bridge. -- Sent from my Android device with K-9 Mail. Please excuse brevity and formatting.
