> 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.
Normally cgraph_nodes with function bodies are first created, later finalized and then analyzed. We copy over the semantic_interposition flag from opt_for_fn to cgraph_node in finalize_function. The ctor there is indeed only for varpool nodes since these do not have their opt_for_var. > > --- 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); So this change should be unnecessary unless there are nodes that are missing finalization stage. It also is not good enough since frontends may change opt_for_fn between node creation and finalization of compilation unit (so even after cgraph_finalize unforutnately, we had another bug about that). The PR was about implicit C++ alias. So the problem is that aliases bypass finalization becuase they are produced by cgraph_node::create_alias that sets definition flag to true. I guess it would be most consistent to give up on having the flag up to date during cgraph construction (i.e. from finalization time down) and compute it during the cgraph_finalize_complation_unit. I will look into that. > > > > 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; This indeed makes sense to me. Honza > > 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)