On 2013.11.19 at 09:44 +0100, Paolo Bonzini wrote: > Il 18/11/2013 20:09, Jan Hubicka ha scritto: > >>> > > this patch switches the default for fat-lto-objects as was documented > >>> > > for a while. > >>> > > -ffat-lto-objects doubles compilation time and often makes users to > >>> > > not notice that > >>> > > LTO was not used at all (because they forgot to use gcc-ar/gcc-nm > >>> > > plugins). > >>> > > > >>> > > Sadly I had to add -ffat-lto-objects to bootstrap. This is because I > >>> > > do not know > >>> > > how to convince our build machinery to use gcc-ar/gcc-nm during the > >>> > > stage2+ > >> > > >> > I've posted a minimal patch set for slim-lto-bootstrap last year, see: > >> > http://thread.gmane.org/gmane.comp.gcc.patches/270842 > >> > > >> > If there's interest I could repost it. > > It would be really nice to have it in indeed. I think we do not really need > > lto-bootstrap.mk and slim-lto-bootstrap.mk, but otherwise the patch seems > > easy > > enough and would save quite some of lto bootstrap testing time... > > Patches 1 and 2 should go upstream first.
OK, but where is upstream? Please note that a general libtool update would fix this issue, too. So, maybe it is just time to upgrade libtool everywhere in gnu-land? > Patch 3 in the series is wrong because Makefile.in is a generated file. > The message does not explain why it is necessary, and it is probably > working around a bug elsewhere. > For patch 4, I agree with Jan that we do not need a separate configuration. The problem is that fixincl links with libiberty.a: /var/tmp/gcc_build_dir/./gcc/xgcc -B/var/tmp/gcc_build_dir/./gcc/ -B/usr/x86_64-pc-linux-gnu/bin/ -B/usr/x86_64-pc-linux-gnu/lib/ -isystem /usr/x86_64-pc-linux-gnu/include -isystem /usr/x86_64-pc-linux-gnu/sys-include -O2 -pipe -static-libstdc++ -static-libgcc -o fixincl fixincl.o fixtests.o fixfixes.o server.o procopen.o fixlib.o fixopts.o ../libiberty/libiberty.a And this archive consists of object files with LTO sections only. So we need to find a way to pass -fuse-linker-plugin to the invocation above. -- Markus
