Someone has repeatedly commented on /r/rust/ that differences are due not so muc...

steveklabnik · on March 21, 2018

I think you're confusing loop unrolling and autovectorization. That said, it's kinda moot, once SIMD is stable, we'll find out :)

igouy · on March 25, 2018

>> I think you're confusing loop unrolling and autovectorization. <<

Here's exactly what I was told -- "This was achieved by manually unrolling a 10-step loop, which compiler apparently could not optimize."