Re: [PATCH][dataflow] Fix PR 32339, bad DF_REF_READ_WRITE marking

["Seongbae Park (박성배, 朴成培)" <seongbae dot park at gmail dot com>]

On 6/18/07, Seongbae Park (박성배, 朴成培) <seongbae.park@gmail.com> wrote:
> On 6/18/07, Seongbae Park (박성배, 朴成培) <seongbae.park@gmail.com> wrote:
> > On 6/15/07, Seongbae Park (박성배, 朴成培) <seongbae.park@gmail.com> wrote:
> > > On 6/14/07, Seongbae Park (박성배, 朴成培) <seongbae.park@gmail.com> wrote:
> > > > "flags" was modified, leaving later calls to df_uses_record
> > > > to mark uses as DF_REF_READ_WRITE.
> > > > This lead to missing REG_DEAD note for such a use,
> > > > causing different views of live ranges
> > > > between forward-scanning (global, using REG_DEAD)
> > > > and backward-scanning (REG_N_CALLS_CROSSED, which is computed by
> > > > regstat_bb_compute_ri).
> > > > This inconsistent view lead to a call-clobbered hard register
> > > > to not have a save area, but later was attempted to be spilled
> > > > because a pseudo register that doesn't cross a live range got allocated to it
> > > > and the forward scanning in global thought that the pseudo reg
> > > > lives across the call.
> > > >
> > > > Bootstrapped and regtested on ia64.
> > > > OK fo mainline ?
> > > >
> > > > ChangeLog:
> > > >
> > > > 2007-06-14  Seongbae Park  <seongbae.park@gmail.com>
> > > >
> > > >         PR rtl-optimization/32339
> > > >         * df-scan.c (df_uses_record): Don't modify flags but just add to it for
> > > >         df_ref_record.
> > > > --
> > > > #pragma ident "Seongbae Park, compiler, http://seongbae.blogspot.com";
> > > >
> > > >
> > > > Index: gcc/df-scan.c
> > > > ===================================================================
> > > > --- gcc/df-scan.c       (revision 125735)
> > > > +++ gcc/df-scan.c       (working copy)
> > > > @@ -2982,9 +2982,9 @@ df_uses_record (struct df_collection_rec
> > > >      case PRE_MODIFY:
> > > >      case POST_MODIFY:
> > > >        /* Catch the def of the register being modified.  */
> > > > -      flags |= DF_REF_READ_WRITE | DF_REF_PRE_POST_MODIFY;
> > > >        df_ref_record (collection_rec, XEXP (x, 0), &XEXP (x, 0), bb, insn,
> > > > -                    DF_REF_REG_DEF, flags);
> > > > +                    DF_REF_REG_DEF,
> > > > +                     flags | DF_REF_READ_WRITE | DF_REF_PRE_POST_MODIFY);
> > > >
> > > >        /* ... Fall through to handle uses ...  */
> > >
> > > Andrew Pinski pointed out that I didn't add the testcase to our testsuite.
> > > Here's the patch for adding the test.
> > > --
> > > #pragma ident "Seongbae Park, compiler, http://seongbae.blogspot.com";
> > >
> > > ChangeLog:
> > >
> > > 2007-06-15  Seongbae Park <seongbae.park@gmail.com>
> > >
> > >         PR rtl-optimization/32339
> > >         * gcc.c-torture/compile/pr32339.c: New test.
> > >
> > >
> > > Index: testsuite/gcc.c-torture/compile/pr32339.c
> > > ===================================================================
> > > --- testsuite/gcc.c-torture/compile/pr32339.c   (revision 0)
> > > +++ testsuite/gcc.c-torture/compile/pr32339.c   (revision 0)
> > > @@ -0,0 +1,17 @@
> > > +/* We used to ICE in insert_save at caller-save.c,
> > > +   due to missing REG_DEAD for register use in post-decrement on ia64. */
> > > +struct city_dialog
> > > +{
> > > +  struct city *pcity;
> > > +  char change_list_names[200][200];
> > > +  int change_list_ids[200];
> > > +};
> > > +change_callback (void)
> > > +{
> > > +  struct city_dialog *pdialog;
> > > +  int n;
> > > +  int i;
> > > +  get_city_dialog_production_full (pdialog->change_list_names[n],
> > > +    pdialog->pcity);
> > > +  pdialog->change_list_ids[n++] = i;
> > > +}
> > >
> >
> > *PING*
> > I've updated the attribution in the changelog entry.
> > No change in the test itself.
> >
> > ChangeLog:
> >
> > 2007-06-15  Martin Michlmayr <tbm@cyrius.com>
> >
> >        PR rtl-optimization/32339
> >        * gcc.c-torture/compile/pr32339.c: New test.
> > --
> > #pragma ident "Seongbae Park, compiler, http://seongbae.blogspot.com";
>
> Both patches committed as revision 125825.
> --
> #pragma ident "Seongbae Park, compiler, http://seongbae.blogspot.com";

As you may have noticed, I committed a different patch with 125825.
The attached patch reverts it.
Sorry for any inconvenience.
--
#pragma ident "Seongbae Park, compiler, http://seongbae.blogspot.com";

Attachment: revert-wrong-changelog-patch.diff.txt
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