[PATCH, PR tree-optimization/65002] Disable SRA for functions wrongly marked as read-only

[Jakub Jelinek]

On Fri, Feb 13, 2015 at 09:47:56AM +0100, Richard Biener wrote:
> > 2015-02-12  Ilya Enkovich  <ilya.enkovich@intel.com>
> >
> >         PR tree-optimization/65002
> >         * tree-cfg.c (pass_data_fixup_cfg): Don't update
> >         SSA on start.
> >         * tree-sra.c (some_callers_have_no_vuse_p): New.
> >         (ipa_early_sra): Reject functions whose callers
> >         assume funciton is read only.

Typo, function.

> > +static bool
> > +some_callers_have_no_vuse_p (struct cgraph_node *node,
> > +                            void *data ATTRIBUTE_UNUSED)
> > +{
> > +  struct cgraph_edge *cs;
> > +  for (cs = node->callers; cs; cs = cs->next_caller)
> > +    if (!cs->call_stmt || !gimple_vuse (cs->call_stmt))
> > +      return true;
> > +
> > +  return false;
> > +}
> > +
> >  /* Convert all callers of NODE.  */
> >
> >  static bool
> > @@ -5116,6 +5130,15 @@ ipa_early_sra (void)
> >        goto simple_out;
> >      }
> >
> > +  if (node->call_for_symbol_thunks_and_aliases
> > +       (some_callers_have_no_vuse_p, NULL, true))
> > +    {
> > +      if (dump_file)
> > +       fprintf (dump_file, "There are callers with no VUSE attached "
> > +                "to a call stmt.\n");
> > +      goto simple_out;
> > +    }
> > +

I wonder if this won't pessimize const functions that just get called with
aggregate arguments passed by value, do those count as memory read or
just as parameters?

	Jakub