| Message ID | 20150731095100.GA1780@tucnak.redhat.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Jul 31, 2015 at 11:51 AM, Jakub Jelinek <jakub@redhat.com> wrote: > 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 <jakub@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; Ah, it's a parameter. I think we don't use TREE_READONLY on that, we use it only on globals. Richard. > if (cilk_for_count) > DECL_CHAIN (t) = DECL_ARGUMENTS (decl); > DECL_ARGUMENTS (decl) = t; > > > Jakub
--- 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;