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

[amker at gcc dot gnu.org]

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

amker at gcc dot gnu.org changed:

           What    |Removed                     |Added
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                 CC|                            |amker at gcc dot gnu.org

--- Comment #9 from amker at gcc dot gnu.org ---
(In reply to Richard Biener from comment #7)
> Technically loop distribution would be one place to add this.  Or SCEV cprop.
It's trivial to detect such pattern in distribution, but we do need to better
handle reduction.
> 
> The pattern matching should be quite cheap - the question is of course how
> many
> different ways to express popcount exist...  so it does somewhat feel like a
> SPEC hack...

Given it's useful in cryptography, it might not be that "hacking".