On Wed, Jan 16, 2013 at 01:44:20PM +0100, Jan Hubicka wrote:
> > Perhaps could you first change cgraph_non_local_node_p_1 and try to check
> > some code
> > if codegen differs significantly? It should not at all.
> > ipa-cp is the sole user of this flag in IPA passes, so you should know what
> > it does.
>
> Thinking deeper of ipa-cp and local virtuals, I think this is all slipperly.
> Local means that all calls to the functions are explicit and known. Obviously
> if function is virutal and new calls may appear by devirtualization, the local
> flag is bogus. I guess the external functions are the only that may be local
> and virtual because somewhere there must be a vtable reference, but to play
> safe, I would suggest marking all virtuals non-local.
>
Right, as discussed on IRC, the patch below therfore modifies
cgraph_only_called_directly_or_aliased_p to return false for virtual
functions (which translates into cleared local flag) and the cloning
machinery to clear that flag.
Bootstrapped and tested on x86_64-linux without any problems. OK for
trunk?
Thanks,
Martin
2013-01-16 Martin Jambor <mjam...@suse.cz>
PR tree-optimizations/55264
* ipa-inline-transform.c (can_remove_node_now_p_1): Never return true
for virtual methods.
* ipa.c (symtab_remove_unreachable_nodes): Never return true for
virtual methods before inlining is over.
* cgraph.h (cgraph_only_called_directly_or_aliased_p): Return false for
virtual functions.
* cgraphclones.c (cgraph_create_virtual_clone): Mark clones as
non-virtual.
testsuite/
* g++.dg/ipa/pr55264.C: New test.
Index: src/gcc/ipa-inline-transform.c
===================================================================
--- src.orig/gcc/ipa-inline-transform.c
+++ src/gcc/ipa-inline-transform.c
@@ -92,9 +92,7 @@ can_remove_node_now_p_1 (struct cgraph_n
those only after all devirtualizable virtual calls are processed.
Lacking may edges in callgraph we just preserve them post
inlining. */
- && (!DECL_VIRTUAL_P (node->symbol.decl)
- || (!DECL_COMDAT (node->symbol.decl)
- && !DECL_EXTERNAL (node->symbol.decl)))
+ && !DECL_VIRTUAL_P (node->symbol.decl)
/* During early inlining some unanalyzed cgraph nodes might be in the
callgraph and they might reffer the function in question. */
&& !cgraph_new_nodes);
Index: src/gcc/ipa.c
===================================================================
--- src.orig/gcc/ipa.c
+++ src/gcc/ipa.c
@@ -241,8 +241,7 @@ symtab_remove_unreachable_nodes (bool be
&& (!cgraph_can_remove_if_no_direct_calls_and_refs_p (node)
/* Keep around virtual functions for possible devirtualization. */
|| (before_inlining_p
- && DECL_VIRTUAL_P (node->symbol.decl)
- && (DECL_COMDAT (node->symbol.decl) || DECL_EXTERNAL
(node->symbol.decl)))))
+ && DECL_VIRTUAL_P (node->symbol.decl))))
{
gcc_assert (!node->global.inlined_to);
pointer_set_insert (reachable, node);
Index: src/gcc/testsuite/g++.dg/ipa/pr55264.C
===================================================================
--- /dev/null
+++ src/gcc/testsuite/g++.dg/ipa/pr55264.C
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-early-inlining -fno-weak" } */
+
+struct S
+{
+ S();
+ virtual inline void foo ()
+ {
+ foo();
+ }
+};
+
+void
+B ()
+{
+ S().foo ();
+}
Index: src/gcc/cgraph.h
===================================================================
--- src.orig/gcc/cgraph.h
+++ src/gcc/cgraph.h
@@ -1164,6 +1164,7 @@ cgraph_only_called_directly_or_aliased_p
gcc_assert (!node->global.inlined_to);
return (!node->symbol.force_output && !node->symbol.address_taken
&& !node->symbol.used_from_other_partition
+ && !DECL_VIRTUAL_P (node->symbol.decl)
&& !DECL_STATIC_CONSTRUCTOR (node->symbol.decl)
&& !DECL_STATIC_DESTRUCTOR (node->symbol.decl)
&& !node->symbol.externally_visible);
Index: src/gcc/cgraphclones.c
===================================================================
--- src.orig/gcc/cgraphclones.c
+++ src/gcc/cgraphclones.c
@@ -319,6 +319,7 @@ cgraph_create_virtual_clone (struct cgra
TREE_PUBLIC (new_node->symbol.decl) = 0;
DECL_COMDAT (new_node->symbol.decl) = 0;
DECL_WEAK (new_node->symbol.decl) = 0;
+ DECL_VIRTUAL_P (new_node->symbol.decl) = 0;
DECL_STATIC_CONSTRUCTOR (new_node->symbol.decl) = 0;
DECL_STATIC_DESTRUCTOR (new_node->symbol.decl) = 0;
new_node->clone.tree_map = tree_map;
