Re: fbranch-probabilities bug

[Hariharan Sandanagobalane <hariharans at picochip dot com>]

Seongbae Park ??? ??? wrote:
> This is the intended behavior, though now I see that the documentation
> isn't very clear.

Can you fix the documentation? As it stands now, it is easy for a user
to be misguided into thinking -fprofile-arcs and fbranch-probabilities
combination would work.

Just out of curiosity, What is the downside to letting people use
-fbranch-probabilities without -fprofile-use?

Cheers
Hari

> You need to use -fprofile-use - the typical usage scenario is to
> compile with -fprofile-generate
> to build an executable to do profile collection, and then compile with
> -fprofile-use
> to build optimized code using the profile data.
>
> Seongbae
>
> On Thu, Jan 8, 2009 at 6:30 AM, Hariharan Sandanagobalane
> <hariharans@picochip.com> wrote:
> > Hi Seongbae,
> > I was doing some work on profiling for picochip, when i noticed what looks
> > to me like a bug. It looks to me that using fbranch-probabilities on the
> > commandline (after a round of profile-generate or profile-arcs) would just
> > not work on any target. Reason..
> >
> > Coverage.c:1011
> >
> >  if (flag_profile_use)
> >    read_counts_file ();
> >
> > Should this not be
> >
> >  if (flag_profile_use || flag_branch_probabilities)  // Maybe more flags
> >    read_counts_file ();
> >
> > ??
> >
> > Of course, i hit the problem later on since the counts were not read, it
> > just assumed that the .gcda file were not available, when it actually was.
> >
> > Thanks
> > Hari