On 9/27/21 11:39 AM, Maxim Kuvyrkov via Gcc wrote:
On 27 Sep 2021, at 16:52, Aldy Hernandez <al...@redhat.com> wrote:
[CCing Jeff and list for broader audience]
On 9/27/21 2:53 PM, Maxim Kuvyrkov wrote:
Hi Aldy,
Your patch seems to slow down 471.omnetpp by 8% at -O3. Could you please take
a look if this is something that could be easily fixed?
First of all, thanks for chasing this down. It's incredibly useful to have
these types of bug reports.
Thanks, Aldy, this is music to my ears :-).
We have built this automated benchmarking CI that bisects code-speed and
code-size regressions down to a single commit. It is still work-in-progress,
and I’m forwarding these reports to patch authors, whose patches caused
regressions. If GCC community finds these useful, we can also setup posting to
one of GCC’s mailing lists.
I second that this sort of thing is incredibly useful. I don't suppose
its easy to do the reverse?... let patch authors know when they've
caused a significant improvement? :-) That would be much less common I
suspect, so perhaps not worth it :-)
Its certainly very useful when we are making a wholesale change to a
pass which we think is beneficial, but aren't sure.
And a followup question... Sometimes we have no good way of determining
the widespread run-time effects of a change. You seem to be running
SPEC/other things continuously then? Does it run like once a
day/some-time-period, and if you note a regression, narrow it down?
Regardless, I think it could be very useful to be able to see the
results of anything you do run at whatever frequency it happens.
