http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45375
--- Comment #167 from Markus Trippelsdorf <markus at trippelsdorf dot de> 2013-01-09 19:58:33 UTC --- (In reply to comment #166) > Markus, the apperance of undefined references I fixed by patch above is highly > sensitive to partitioning and inlining decision. Can you, please, check if > the > problem with PGO remains? It may be another instance of the same issue. Just checked it using your patch from comment 165, but the issue from comment 162 is still there: /usr/lib/gcc/x86_64-pc-linux-gnu/4.8.0/../../../../x86_64-pc-linux-gnu/bin/ld: error: /tmp/ccACx905.ltrans6.ltrans.o: requires dynamic R_X86_64_PC32 reloc against '_ZN13nsXULDocument14MaybeBroadcastEv.466048' which may overflow at runtime; recompile with -fPIC /tmp/ccACx905.ltrans6.ltrans.o:ccACx905.ltrans6.o:function nsRunnableMethodTraits<void (nsXULDocument::*)(), true>::base_type* NS_N ewRunnableMethod<nsXULDocument*, void (nsXULDocument::*)()>(nsXULDocument*, void (nsXULDocument::*)()) [clone .local.42120] [clone .constprop.89117]: error: undefined reference to 'nsXULDocument::MaybeBroadcast() [clone .466048]' /tmp/ccACx905.ltrans6.ltrans.o:ccACx905.ltrans6.o:function nsRunnableMethodTraits<void (nsXULDocument::*)(), true>::base_type* NS_N ewRunnableMethod<nsXULDocument*, void (nsXULDocument::*)()>(nsXULDocument*, void (nsXULDocument::*)()) [clone .local.42120] [clone .constprop.89117]: error: undefined reference to 'nsXULDocument::MaybeBroadcast() [clone .466048]' Also the memory usage went through the roof (not sure if this caused by your patch or my recent git-pull of mozilla-central): over 9GB RAM is needed (not much fun on my 8GB test-machine). (So I will stop testing Firfox for now, until LTO/PGO memory usage gets sane again (hopefully for 4.9).)