> > On Tue, 19 Nov 2013, Jan Hubicka wrote: > > > > > > Hmm, gcc/gcc.c still reads: > > > > > > > > 690 /* Conditional to test whether the LTO plugin is used or not. > > > > 691 FIXME: For slim LTO we will need to enable plugin > > > > unconditionally. This > > > > 692 still cause problems with PLUGIN_LD != LD and when plugin is > > > > built but > > > > 693 not useable. For GCC 4.6 we don't support slim LTO and thus we > > > > can enable > > > > 694 plugin only when LTO is enabled. We still honor explicit > > > > 695 -fuse-linker-plugin if the linker used understands -plugin. */ > > > > 696 > > > > 697 /* The linker has some plugin support. */ > > > > 698 #if HAVE_LTO_PLUGIN > 0 > > > > 699 /* The linker used has full plugin support, use LTO plugin by > > > > default. */ > > > > 700 #if HAVE_LTO_PLUGIN == 2 > > > > > > Hmm, I see, your problem is that there is no -flto? > > > > The 4.6 consideration is irrelevant, I don't understand your question ... > > for disabled LTO you can't run bootstrap-lto ... > > The problem is that you have .a library consisting of slim LTO objects and > you link > with it during configure check without -flto. > In this case we do not run plugin and never notice that LTO objects are > involved. > I think in linger run we should do it. I meant in longer run we should switch into using plugin all the time, so slim LTO archives can be used this way. It does come with some linktime cost (never measured if it is important or not)
Honza
