Re: [PING][PATCH] [modulo-sched] Change the ddg's construction

[Ayal Zaks <ZAKS at il dot ibm dot com>]

Revital1 Eres/Haifa/IBM wrote on 30/07/2007 22:13:53:

>
> > Kenny, thanks for the quick approval. Any follow-up changes needed for
df,
> > now that df_ru_add_problem() is left without a caller?
> >
> > Revital, this is ok with me too, with some minor comments below.
> >
> > Ayal.
>
> Thanks for the comments.  Regarding the following -
>
> > > -  /* Find inter-loop anti deps.  We are interested in uses of the
block
> > that
> > > -     appear below all defs; this implies that these uses are killed.
*/
> > > -  EXECUTE_IF_SET_IN_BITMAP (ru_bb_info->kill, 0, u_num, bi)
> > > -    {
> > > -      struct df_ref *use = DF_USES_GET (u_num);
> > > -      if (!(DF_REF_FLAGS (use) & DF_REF_IN_NOTE))
> >
> > Please comment why we no longer check and exclude such uses.

> I'll address this in a separate patch which means we currently do not
> exclude uses that appears inside a REG_EQUAL or REG_EQUIV note; I've
> added ??? mark to revisit this issue later on.
>
> Attached is the patch including the comments.
>
> OK to mainline?
>

OK.

Instead of checking
> +          if (INSN_UID (first_def->insn) != INSN_UID (last_def->insn))
for anti-deps you could simply check
> +      if (last_def->id == first_def->id)
as done for output-deps.

Ayal.


> Thanks,
> Revital

> 2007-07-30  Revital Eres  <eres@il.ibm.com>
>
>         * ddg.c (add_deps_for_def): Rename to...
>         (add_cross_iteration_register_deps): This.  Change implementation
>         to use only reaching def and def-use chains to construct the
>         inter loop dependencies.
>         (add_deps_for_use): Remove function.
>         (build_inter_loop_deps): Call add_cross_iteration_register_deps
>         function to build the inter loop dependencies.
>         * modulo-sched.c (sms_schedule): Build only
>         reaching def and def-use chains for the propose of the ddg
>         construction.
>
> [attachment "patch_ddg_30.txt" deleted by Ayal Zaks/Haifa/IBM]