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


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";

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