eflist really slow on osx

[dgleich]

@yuyongyang800 can you try and reproduce something for me? checkout the branch eflist-refactor. then run eflist_perf ../data/harvard500.offsets 100000

On my mac, this runs at 6000 offsets/sec

On my linux box, this runs at a few million offsets/sec.

Obviously, there is something wrong!

David

[dgleich]

My windows box also gives a few million (3M, to be exact.)

[yuyongyang800]

Let me see what's going on there.

[dgleich]

Okay, THANKS!

My quick diagnostic pointed to eflist_get as the place where it's slow (not surprising), but then the issue is ... bit_array_get or select_rank?

Maybe it makes sense to profile those two independently to see which is slower on linux/osx?

[yuyongyang800]

The bottleneck is the select_rank() function. I am trying to understand why this is so slow on osx.