> 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.
-fuse-linker-plugin is now default at the same time as -fno-fat-object-files is, so there should be no need for using this switch explicitely. Honza > > -- > Markus
