> > On Tue, Mar 26, 2013 at 4:54 AM, John Frankish <j-frankish@xxxxxxx> wrote: > > I've been experimenting with "-flto" to compile various source packages. > > > > Using binutils-2.23.1 and gcc-4.7.2, both compiled with "--enable-lto" > > > > and > > > > CC="gcc -flto -fuse-linker-plugin -march=i486 -mtune=i686 -Os -pipe" > > CXX="g++ -flto -fuse-linker-plugin -march=i486 -mtune=i686 -Os -pipe > > -fno-exceptions -fno-rtti" ./configure --yada-yada > > > > > > glibc-2.17 ./configure fails complaining that ld does not support array > > something or other (removing "-flto -fuse-linker-plugin" fixes this). Is there a patch or another way to be able to compile glibc with LTO? > > 1. Am I using "-flto" correctly? > > Seems like it. > > > > 2. I'm removing "-O2" from the Makefiles - do I need to remove "-g" as > well? > > It depends on whether you want debug info or not. It doesn't really have > anything to do with -flto. I'd seen several posts stating that there were problems with -flto and debug symbols with gcc-4.6.x > -O2 vs. -Os also doesn't really have anything to do with -flto. -flto will work > with both. > > Your static libraries are larger because they now include LTO information > used at link time. The increase in size is not relevant to the final linked > program. Is there a way to remove this LTO information (with strip)? Otherwise I'm going to have to compile with LTO for apps/so libs and again without LTO for static libs...
