On Thursday 15 July 2010 19:19:13 Paul Brook wrote: > However changing the ABI doesn't solve many of the underlying problem. > Specifically how to provide optimized binaries that take advantage of new > features on modern CPUs while still supporting older hardware.
You can't bridge that gap. There are many optimized distros out there, each of them requiring a specific minimum to run, for a reason. It would be impossible or at the very least, extremely hard for them to maintain backwards compatibility, and in the end, what for? Having yet another substandard performance port and read articles about how Gentoo or even Ubuntu beats the crap out of base Debian in speed? (I know Debian is not about speed, but seriously, it doesn't have to be *slow*). > Switching to the hard-float ABI certainly does give some benefit. While 20% > isn't a trivial difference, it's important to keep this in context. This > is on top of what I'd guess is a 10x (i.e. 1000%) speedup achieved without > breaking the ABI and requiring a whole new port. If you're really serious > about performance then a NEON optimized version of your critical code > should get you annother 4x or so on a Cortex-A8. Yes, and we're working on NEON optimizations as well, but that's much harder, as it requires algorithm optimization and not just a simple recompile - autovectorization is a joke. Eg. optimizing NEON took less than a day, but I already knew how it worked as I had done the AltiVec port before, and because it was such a beautiful design. Stuff like zlib took longer -I had to rework the algorithm to paralellize it- and it was useless after all because the license prevents altered binary releases. > What you're describing here is multiarch. Multiarch still isn't there, even after at least 5 years when I saw the first presentation. It may have been hard on x86/x86_64 or ppc/ppc64 where there were only 2 variants, here we have what? 5? 10? I seriously think it's not worth it. It's much easier and less intrusive to the end user to not force upon him all the variants and just have a lean system that does what it promises to do. Regards Konstantinos -- To UNSUBSCRIBE, email to debian-arm-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/201007151940.02267.mar...@genesi-usa.com
