https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109695
--- Comment #37 from Andrew Macleod <amacleod at redhat dot com> ---
(In reply to CVS Commits from comment #36)
> For the curious, a particular hot spot for IPA in this area was:
>
> ipcp_vr_lattice::meet_with_1 (const value_range *other_vr)
> {
> ...
> ...
> value_range save (m_vr);
> m_vr.union_ (*other_vr);
> return m_vr != save;
> }
>
> The problem isn't the resizing (since we do that at most once) but the
> fact that for some functions with lots of callers we end up a huge
> range that gets copied and compared for every meet operation. Maybe
> the IPA algorithm could be adjusted somehow??.
isn't the the same thing as
return m_vr.union_ (*other_vr);
which should be much faster without all the copying... ?
