On Tue, 3 Nov 2015, Tom de Vries wrote:
> On 03/11/15 16:08, Richard Biener wrote:
> > On Tue, 3 Nov 2015, Tom de Vries wrote:
> >
> > > On 01/11/15 19:20, Tom de Vries wrote:
> > > > On 01/11/15 19:03, Tom de Vries wrote:
> > > > > So, the new patch series is:
> > > > >
> > > > > 1 Rename make_restrict_var_constraints to
> > > > > make_param_constraints
> > > > > 2 Handle recursive restrict in function parameter
> > > > >
> > > > > I'll repost in reply to this message.
> > > > >
> > > >
> > > > This patch adds handling of all the restrict qualifiers in the type of a
> > > > function parameter.
> > > >
> > >
> > > And reposting an updated version, now that the toplevel parameter in
> > > make_param_constraints has been eliminated.
> >
> > @@ -5195,6 +5197,8 @@ struct fieldoff
> > unsigned may_have_pointers : 1;
> >
> > unsigned only_restrict_pointers : 1;
> > +
> > + varinfo_t restrict_var;
> > };
> >
> > store the varinfo ID here, 'unsigned int restrict_var' which ends
> > up not changing fieldoff size. get_varinfo (restrict_var) will get
> > you the varinfo_t.
>
> Done, attached.
>
> >
> > @@ -5374,6 +5380,19 @@ push_fields_onto_fieldstack (tree type,
> > vec<fieldoff_s> *fieldstack,
> > = (!has_unknown_size
> > && POINTER_TYPE_P (field_type)
> > && TYPE_RESTRICT (field_type));
> > + if (handle_param
> > + && e.only_restrict_pointers
> > + && !type_contains_placeholder_p (TREE_TYPE
> > (field_type)))
> > + {
> > + varinfo_t rvi;
> > + tree heapvar = build_fake_var_decl (TREE_TYPE
> > (field_type));
> > + DECL_EXTERNAL (heapvar) = 1;
> > + rvi = create_variable_info_for_1 (heapvar,
> > "PARM_NOALIAS",
> > + true, true);
> > + rvi->is_restrict_var = 1;
> > + insert_vi_for_tree (heapvar, rvi);
> > + e.restrict_var = rvi;
> > + }
> >
> > hmm, can you delay this to the point we actually will use field-sensitive
> > stuff? That is, until create_variable_info_for_1 decided to use a
> > multi-field variable?
>
> AFAIU your concern is that in the current patch we're creating heapvars that
> may end up being ignored, f.i. if we hit the MAX_FIELDS_FOR_FIELD_SENSITIVE
> threshold?
Yes (or for other reasons).
> > Say, here:
> >
> > + if (handle_param
> > + && newvi->only_restrict_pointers
> > + && fo->restrict_var != NULL)
> > + {
> > + make_constraint_from (newvi, fo->restrict_var->id);
> > + make_param_constraints (fo->restrict_var);
> > + }
> >
> > ? Looks like then you don't need the new field at all.
> >
>
> The build_fake_var_decl call needs TREE_TYPE (field_type), the type the
> restrict pointer field points to.
>
> The field type is no longer available once we've abstracted the struct type
> into a field stack in create_variable_info_for_1.
>
> I think I can postpone the creation of the heapvar till where you suggest in
> create_variable_info_for_1, but I'd still need a means
> to communicate the TREE_TYPE (field_type) from push_fields_onto_fieldstack to
> create_variable_info_for_1.
>
> A simple implementation would be a new field:
> ...
> @@ -5195,6 +5197,8 @@ struct fieldoff
> unsigned may_have_pointers : 1;
>
> unsigned only_restrict_pointers : 1;
> +
> + tree restrict_pointed_type;
> };
> ...
> Which AFAIU will change fieldoff size.
It's ok to change fieldoff size if there is a reason to ;)
Patch is ok along this line.
Thanks,
Richard.
