[Bug lto/45375] [meta-bug] Mozilla does not build with LTO

["hubicka at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45375

--- Comment #8 from Jan Hubicka <hubicka at gcc dot gnu.org> 2010-10-15 01:29:38 UTC ---
Updated summary...

 - Last patch needed to get Mozilla working is posted as
http://gcc.gnu.org/ml/gcc-patches/2010-10/msg01286.html
 - Configuration needs to be done with -fwhopr for C++ and -flto for C, to get
around sqlite problem (PR44897)
 - Debugging still needs to be disabled
 - Recent Gold is needed

 - Peak memory use is about 4GB, still more than we should need.  It is WPA
stage having too many declarations in it.
 - We probably could do better on devirtualization in constructors for addref.

With -O3 --param inline-unit-growth -fwhopr=jobserv the code size seems
comparable with non-LTO -Os build, speed with non-LTO -O3 build.  This seems
quite good news.

Lacking debug info build seems to be the only remaining showstopper for
practical use.