> This patch mentions that -flto now generates slim objects. That's especially > relevant for static libraries as one can there run into surprises, if one > does not know about gcc-ar. > > OK - or do you have a better suggestion? > > Tobias > > > --- changes.html 8 Mar 2014 20:45:54 -0000 1.63 > +++ changes.html 21 Mar 2014 09:10:32 -0000 > @@ -65,6 +65,13 @@ > <li>Function bodies are now loaded on-demand and released early > improving > overall memory usage at link time.</li> > <li>C++ hidden keyed methods can now be optimized out.</li> > + <li>By default, compiling with the <code>-flto</code> option now > generates > + slim objects files (<code>.o</code>) which only contain intermediate > + language representation for LTO. Use <code>-ffat-lto-objects</code> > to > + create files which contain additionally the object code. To > generate > + static libraries suitable for LTO processing, use > <code>gcc-ar</code> > + and <code>gcc-ranlib</code> (requires that <code>ar</code> and > + <code>ranlib</code> have been compiled with plugin support).</li>
Ah, seems I forgot some of wwwdocs updates, since I wrote one already. But yours is better. I would perhaps mention that with slim objects the LTO build times are often better (you can reffer i.e. to SPEC2k6 compilation time) and also mention gcc-nm. Honza > </ul> > Memory usage building Firefox with debug enabled was reduced from 15GB to > 3.5GB; link time from 1700 seconds to 350 seconds.
