Re: PING: [PATCH]: Fix -fbranch-probabilities

[Christian Bruel <christian dot bruel at st dot com>]

On 08/27/2011 02:04 AM, Jan Hubicka wrote:
> > Hello,
> >
> > Could I have a review for the trivial patch posted in
> > http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01123.html
> >
> > -fprofile-use sets flag_branch_probabilities.
> >
> > But we should also be able to use -fbranch-probabilities on its own
> > using the information generated by -fprofile-arcs, as documented.
>
> OK, thanks!  I was under impression that some of gcov tests still use
> -fprofile-arcs -fbranch-probabilities pair.

yes, indeed, this is was the documentation claims:
http://gcc.gnu.org/onlinedocs/gccint/C-Tests.html#C-Tests.

e.g for :

gcc.misc-tests
    ...
    bprob*.c
        Test -fbranch-probabilities using gcc.misc-tests/bprob.exp,
    ...

but bprob.exp sets feedback_options to "-fprofile-use"

> It don't seem to be the
> case, so if you add a testcase, you get extra score ;)

I feel more like fixing the bprob.exp discrepancy to have the correct 
pairing with the following. This will act as the testcase, since those 
tests fail without the patch.

OK ?


Index: gcc.misc-tests/bprob.exp
===================================================================
--- gcc.misc-tests/bprob.exp    (revision 178096)
+++ gcc.misc-tests/bprob.exp    (working copy)
@@ -48,7 +48,7 @@
 load_lib profopt.exp

 set profile_options "-fprofile-arcs"
-set feedback_options "-fprofile-use"
+set feedback_options "-fbranch-probabilities"

 foreach profile_option $profile_options feedback_option 
$feedback_options {
     foreach src [lsort [glob -nocomplain $srcdir/$subdir/bprob-*.c]] {

---------
2011-08-29  Christian Bruel  <christian.bruel@st.com>

	* gcc.misc-tests/bprob.exp (feedback_options): Set -fbranch-probabilities.
---------

Thanks

Christian


> Honza
> > Many thanks
> >
> > Christian