On Wed, 20 Apr 2022, Jakub Jelinek wrote:
> Hi!
>
> cgraph_node has a semantic_interposition flag which should mirror
> opt_for_fn (decl, flag_semantic_interposition). But it actually is
> initialized not from that, but from flag_semantic_interposition in the
> explicit symtab_node (symtab_type t)
> : type (t), resolution (LDPR_UNKNOWN), definition (false), alias (false),
> ...
> semantic_interposition (flag_semantic_interposition),
> ...
> x_comdat_group (NULL_TREE), x_section (NULL)
> {}
> ctor. I think that might be fine for varpool nodes, but since
> flag_semantic_interposition is now implied from -Ofast it isn't correct
> for cgraph nodes, unless we guarantee that cgraph node for a particular
> function decl is always created while that function is
> current_function_decl. That is often the case, but not always as the
> following function shows.
> Because symtab_node's ctor doesn't know for which decl the cgraph node
> is being created, the following patch keeps that as is, but updates it from
> opt_for_fn (decl, flag_semantic_interposition) when we know that, or for
> clones copies that flag (often it is then overridden in
> set_new_clone_decl_and_node_flags, but not always).
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK.
Richard.
> 2022-04-20 Jakub Jelinek <ja...@redhat.com>
>
> PR ipa/105306
> * cgraph.cc (cgraph_node::create): Set node->semantic_interposition
> to opt_for_fn (decl, flag_semantic_interposition).
> * cgraphclones.cc (cgraph_node::create_clone): Copy over
> semantic_interposition flag.
>
> * g++.dg/opt/pr105306.C: New test.
>
> --- gcc/cgraph.cc.jj 2022-02-04 14:36:54.069618372 +0100
> +++ gcc/cgraph.cc 2022-04-19 13:38:06.223782974 +0200
> @@ -507,6 +507,7 @@ cgraph_node::create (tree decl)
> gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
>
> node->decl = decl;
> + node->semantic_interposition = opt_for_fn (decl,
> flag_semantic_interposition);
>
> if ((flag_openacc || flag_openmp)
> && lookup_attribute ("omp declare target", DECL_ATTRIBUTES (decl)))
> --- gcc/cgraphclones.cc.jj 2022-01-18 11:58:58.948991114 +0100
> +++ gcc/cgraphclones.cc 2022-04-19 13:38:43.594262397 +0200
> @@ -394,6 +394,7 @@ cgraph_node::create_clone (tree new_decl
> new_node->versionable = versionable;
> new_node->can_change_signature = can_change_signature;
> new_node->redefined_extern_inline = redefined_extern_inline;
> + new_node->semantic_interposition = semantic_interposition;
> new_node->tm_may_enter_irr = tm_may_enter_irr;
> new_node->externally_visible = false;
> new_node->no_reorder = no_reorder;
> --- gcc/testsuite/g++.dg/opt/pr105306.C.jj 2022-04-19 13:42:33.908054114
> +0200
> +++ gcc/testsuite/g++.dg/opt/pr105306.C 2022-04-19 13:42:08.859403045
> +0200
> @@ -0,0 +1,13 @@
> +// PR ipa/105306
> +// { dg-do compile }
> +// { dg-options "-Ofast" }
> +
> +#pragma GCC optimize 0
> +template <typename T> void foo (T);
> +struct B { ~B () {} };
> +struct C { B f; };
> +template <typename> struct E {
> + void bar () { foo (g); }
> + C g;
> +};
> +template class E<char>;
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Ivo Totev; HRB 36809 (AG Nuernberg)
