This is a summary of the current status of AMD Geode optimizations that we might be interested in.
Sorry for the long Cc list, I just wanted to make sure all interested parties can read and comment even though they're not subscribed to our devel list. Things are being tracked in this bug: http://dev.laptop.org/ticket/118 GCC === The original rationale and patch by Vladimir Makarov is here: http://gcc.gnu.org/ml/gcc-patches/2006-08/msg00452.html And it has already been debated here last year: http://mailman.laptop.org/pipermail/devel/2006-August/001232.html I've backported AMD's geode patches from GCC's trunk to 4.2 and I'm currently regtesting them for inclusion in the 4.2-branch. I'm afraid we won't be allowed to backport them to 4.1 too, because that branch is only open to fixes addressing serious regressions. Anyway, we could ask Jakub to add the Geode patches to F7's GCC package as it's they won't impact other architectures, so they're pretty safe. glibc ===== Optimized routines and benchmark results are here: http://dev.laptop.org/git.do?p=geode-perf;a=tree I talked about it with Rob Savoye, who has been porting this work with glibc. Patches are due soon, and I will push them to the glibc maintainers because Rob will be away for a few days. Glibc 2.6 has been released recently and F7 is shipping it. Of course we don't want to wait a full release cycle of both projects, so we're going to patch either our glibc RPM or preferably Fedora's. Building custom packages ======================== I talked about it shortly with Chris Blizzard and, of course, he'd rather try to avoid things such as rebuilding all packages with custom GCC flags or adding yet another sub-arch along with i386, i586 and i686. We don't have the numbers yet, but we'll most probably need to custom-build at least glibc. Other candidates include openssl, the X server, python and maybe cairo. I'm not sure how much burden would originate from this in our build infrastructure. If we install a custom GCC package configured with "--with-arch=geode", we wouldn't need to tweak spec files or Makefiles, at least in most cases. But anyway, we'd have to rename the packages because calling them something like "xyzzy.i386.rpm" while they're actually for the Geode would be criminal at least. Then there's also this fine problem to be addressed: http://gcc.gnu.org/ml/gcc-patches/2006-08/msg00452.html http://sourceware.org/ml/binutils/2006-07/msg00360.html I've discussed it with Jordan Crouse and the bottom line is that, basically, building for i686 on the Geode could be dangerous because it doesn't support the NOPL opcode that GAS could use and for other minor differences that may bite us in the future. As of build 428, we're still shipping with i686 versions of glibc and openssl. For safety, these should either be downgraded to i586 or replaced by the Geode specific versions. -- // Bernardo Innocenti \X/ http://www.codewiz.org/ _______________________________________________ Devel mailing list Devel@laptop.org http://mailman.laptop.org/mailman/listinfo/devel
