This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Make ipa-icf to not prevent devirtualization
- From: Jan Hubicka <hubicka at ucw dot cz>
- To: gcc-patches at gcc dot gnu dot org
- Date: Fri, 15 Jan 2016 12:01:48 +0100
- Subject: Make ipa-icf to not prevent devirtualization
- Authentication-results: sourceware.org; auth=none
Hi,
this patch avoid ipa-icf to take away body of a virtual function which is a subject
of later devirtualization.
Bootstrapped/regtested x86_64-linux, comitted.
Honza
PR ipa/68148
* ipa-icf.c (sem_function::merge): Virtual functions may become
reachable even if they address is not taken and there are no
idrect calls.
* testsuite/g++.dg/ipa/devirt-49.C: New testcase.
Index: ipa-icf.c
===================================================================
--- ipa-icf.c (revision 232407)
+++ ipa-icf.c (working copy)
@@ -1305,6 +1305,7 @@ sem_function::merge (sem_item *alias_ite
/* If all callers was redirected, do not produce wrapper. */
if (alias->can_remove_if_no_direct_calls_p ()
+ && !DECL_VIRTUAL_P (alias->decl)
&& !alias->has_aliases_p ())
{
create_wrapper = false;
Index: testsuite/g++.dg/ipa/devirt-49.C
===================================================================
--- testsuite/g++.dg/ipa/devirt-49.C (revision 0)
+++ testsuite/g++.dg/ipa/devirt-49.C (revision 0)
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-ipa-devirt" } */
+struct Interface {
+ virtual ~Interface() {}
+ virtual void virtualFunc() = 0;
+ virtual void virtualFunc2() = 0;
+};
+
+struct Concrete : Interface {
+ int counter_;
+ Concrete() : counter_(0) {}
+ void virtualFunc() { counter_++; }
+ void virtualFunc2() { counter_++; }
+};
+
+void test(Interface &c) {
+ c.virtualFunc();
+ c.virtualFunc2();
+}
+/* { dg-final { scan-ipa-dump "2 speculatively devirtualized" "devirt" } } */