[Bug middle-end/82479] missing popcount builtin detection

[kugan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82479

--- Comment #4 from kugan at gcc dot gnu.org ---
(In reply to Andrew Pinski from comment #2)
> Confirmed. How useful this optimization is questionable.

This code is part of spec2017/deepsjeng. There is some gain if we can. 

> 
> Gcc has __builtin_popcount which can be used.

I agree.