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Re: [PATCH] decide edge's hotness when there is profile info
- From: Teresa Johnson <tejohnson at google dot com>
- To: Jan Hubicka <hubicka at ucw dot cz>
- Cc: Dehao Chen <dehao at google dot com>, Xinliang David Li <davidxl at google dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 11 Nov 2013 09:17:40 -0800
- Subject: Re: [PATCH] decide edge's hotness when there is profile info
- Authentication-results: sourceware.org; auth=none
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On Mon, Nov 11, 2013 at 9:13 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>> On Mon, Nov 11, 2013 at 8:22 AM, Jan Hubicka <hubicka@ucw.cz> wrote:
>> >> I have a warning like that already in drop_profile(). Is that
>> >
>> > I think it should be warning (or silent) for COMDAT and error/note for
>> > other functions (depending on flag_profile_correction).
>> > I guess drop_profile is better place for it indeed.
>>
>> I don't want to warn for COMDAT since this is currently an expected
>> issue in that case, so I'm afraid it will be too noisy (but there is a
>> note emitted to the dump file to track how often this occurs). So
>> currently the warning is only emitted in cases where we don't expect
>> it to occur (e.g. non-comdat).
>
> I see, I misread it.
> The non-comdat warning IMO ought go the same way as the other profile confussions.
> I guess something like
> if (!flag_profile_correction)
> error (...);
> like existing cases in profile.c
Ok, will do (emitting a note to the dump file as in other cases in
profile.c that do this same thing).
>>
>> I didn't find any warnings being emitted when running this for spec or
>> internal benchmarks, so how about instead of a warning, I handle it
>> like you suggest above: depending on the setting of
>> flag_profile_correction either error or emit a note to the dump file
>> under MSG_MISSED_OPTIMIZATION?
>
> Yep, lets just go with error with !flag_profile_correction and being silent
> otherwise.
> If we want to go with warnings, we need to change all the similar places
> in profile.c and elsewhere.
>>
>> Ah - I just realized I am already checking profile_status_for_function
>> above and adding to the worklist if it is still PROFILE_READ. Since I
>> call drop_profile before adding to the worklist, we can't end up
>> adding multiple times. So I don't think there is currently an issue
>> with this.
>
> Yep, indeed.
>
> The patch is OK with the error message as discussed above.
Ok, will do that and fix a couple of minor issues mentioned by Steven
(missing comment and incorrect indentation in one spot). Will retest
just to make sure I didn't miss any warnings which will now be errors.
Thanks,
Teresa
>
> Thanks.
> Honza
>>
>> Thanks,
>> Teresa
>>
>> >
>> > Honza
>> >>
>> >> Thanks,
>> >> Teresa
>> >>
>> >> >
>> >> > OK, with these changes.
>> >> >
>> >> > Honza
>> >>
>> >>
>> >>
>> >> --
>> >> Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413
>>
>>
>>
>> --
>> Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413
--
Teresa Johnson | Software Engineer | tejohnson@google.com | 408-460-2413