[Bug middle-end/36041] Speed up builtin_popcountll

[crrodriguez at opensuse dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36041

--- Comment #19 from Cristian Rodríguez <crrodriguez at opensuse dot org> ---
(In reply to Jakub Jelinek from comment #18)
> I think it is a bad idea to introduce the IFUNC into libgcc_s, because then
> while you speed up the few users of this builtin, you slow down all users of
> libgcc_s (pretty much all C++ programs and lots of C programs), because they
> will need to resolve the ifunc.  For a very heavily used builtin perhaps,
> but for a rarely used one it just isn't a good idea.  User's can just use
> multi-versioning themselves and use __builtin_popcount* in the
> multi-versioned function.

Hold on..Apparently I used ambiguous language in my comment.. adding ifuncs to
libgcc* was not my real suggestion, but to EMIT such IFUNC s in the resulting
final user code when the target environment allows it. One generic, one
hardware/arch specific.