On Fri, Jul 31, 2015 at 11:41:47AM +0200, Richard Biener wrote:
> >> Const qualification of a pointer or reference doesn't result in any
> >> optimization. The
> >> decl you refer to has to be constant.
> >
> > Even if the pointer would be addressable?
>
> Yes, it's the decls readonly setting that matters, not type qualification.
>
> > But it isn't in this case.
> > Still the
> > if (is_gimple_omp_offloaded (ctx->stmt))
> > type = build_qualified_type (type, TYPE_QUAL_CONST);
> > would constify what the reference refers to. Maybe it doesn't make
> > any difference either due to TYPE_QUAL_RESTRICT on the reference though.
>
> Maybe.
Ok, so I'll test:
2015-07-31 Jakub Jelinek <ja...@redhat.com>
* omp-low.c (fixup_child_record_type): Const qualify *.omp_data_i.
(create_omp_child_function): Set TREE_READONLY on .omp_data_i.
--- gcc/omp-low.c.jj 2015-07-31 11:08:38.581201231 +0200
+++ gcc/omp-low.c 2015-07-31 11:49:14.764734054 +0200
@@ -1824,6 +1824,11 @@ fixup_child_record_type (omp_context *ct
layout_type (type);
}
+ /* In a target region we never modify any of the pointers in *.omp_data_i,
+ so attempt to help the optimizers. */
+ if (is_gimple_omp_offloaded (ctx->stmt))
+ type = build_qualified_type (type, TYPE_QUAL_CONST);
+
TREE_TYPE (ctx->receiver_decl)
= build_qualified_type (build_reference_type (type), TYPE_QUAL_RESTRICT);
}
@@ -2521,6 +2526,7 @@ create_omp_child_function (omp_context *
DECL_ARG_TYPE (t) = ptr_type_node;
DECL_CONTEXT (t) = current_function_decl;
TREE_USED (t) = 1;
+ TREE_READONLY (t) = 1;
if (cilk_for_count)
DECL_CHAIN (t) = DECL_ARGUMENTS (decl);
DECL_ARGUMENTS (decl) = t;
Jakub
