On Thu, May 09, 2013 at 03:52:20PM +0200, Martin Jambor wrote: > On Tue, May 07, 2013 at 11:43:33PM +0200, Jan Hubicka wrote: > > > Hi, > > > > > > the problem in PR 57084 is that late PRE devirtualization creates a > > > direct call to a decl fro which we only have an inlined call graph > > > mode in the given partition. I tried to find a most universal place > > > where to fix it because this problem is not special to type-based > > > devirtualization and in theory can be caused by any call to a decl > > > that is grabbed from a constructor. I think the best place is the > > > following one-liner, because all such decls should go through > > > canonicalize_constructor_val. > > > > > > Bootstrapped and tested on x86_64-linux, fixes the testcase (at -m32) > > > and I have happened to also LTO build Mozilla Firefox with it. OK for > > > trunk? > > > > Is this change needed for 4.8, too? It would be OK there. > > Although the testcase shows the problem relies on code that is new in > 4.9, I think that yes, even the current devirtualization by looking > into constructors can hit the bug. So I am going to commit it to 4.8 > after testing on that branch.
Except that there is no such thing as cgraph_get_create_real_symbol_node in 4.8. I suppose it's not worth backporting it without a bug triggering there. However, this makes me think whether we should not commit the original one-line patch to trunk first, even though we will zap cgraph_get_create_real_symbol_node later, so that the patch can be found and backported more easily if the need to backport it ever arises... Martin > > > > > For 4.9 I would preffer replacing cgraph_get_create by > > cgraph_get_create_real_symbol_node. I believe that all users of > > cgraph_get_create are not interested in inline nodes. I just did not want to > > make such intrusive change for 4.8... > > I've looked at all calls to cgraph_get_create_node and pretty much all > of them either really want cgraph_get_create_real_symbol_node or at > least will not be harmed by doing that. The only two calls I was not > so sure about were the one in lto-cgraph.c and in particular the one > in lto-streamer-in.c. I'm afraid they might create an extra cgraph > node in LTRANS when we would actually want the inlined one. What do > you think? > > I'll give it a go anyway. Thanks, > > Martin >
