This is the mail archive of the mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [PATCH, 4.9/4.10] Profile based option tuning

I guess some optimizations are controlled only by "optimize_size", not
by the profile.
Other optimizations are controlled by the profile.
So this patch does not have very much effectiveness (only 0.9% size reduction).

2014-07-23 17:26 GMT+08:00 Richard Biener <>:
> On Wed, Jul 23, 2014 at 2:39 AM, Pengfei Yuan <> wrote:
>> In the experiment, about 60% (1019/1699) profile data files are empty
>> (all counters are zero).
> Well, but you are globally overriding options even for the parts with
> profile.  The whole point of profile-feedback is to get at the interesting
> parts (those with non-zero counters).
> What you say is that not enough parts of the compiler care for
> the actual profiles and thus portions with all-zero counters are
> treated as if they were hot?  Then better fix that.
> Richard.
>> 2014-07-22 21:39 GMT+08:00 Richard Biener <>:
>>> On Mon, Jul 21, 2014 at 7:13 AM, Pengfei Yuan <> wrote:
>>>> Hi,
>>>> This patch tunes optimization options based on profile data:
>>>> * Disable PGO options if profile is not available or empty.
>>>> * Optimize for size if profile is available but empty.
>>> Err ... these don't seem interesting cases to "optimize" for?
>>> Richard.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]