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Ocamlopt x86-32 and SSE2
-
Pascal Cuoq
-
Xavier Leroy
- Sylvain Le Gall
- Richard Jones
- Florian Weimer
-
Xavier Leroy
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Date: | 2009-05-12 (12:41) |
From: | Richard Jones <rich@a...> |
Subject: | Re: [Caml-list] Ocamlopt x86-32 and SSE2 |
On Tue, May 12, 2009 at 11:37:17AM +0200, Xavier Leroy wrote: > Richard Jones: > >AMD Geode then ... > > Apparently, recent versions of the Geode support SSE2 as well. > Low-power people love vector instruction sets, because it lets them do > common tasks like audio and video decoding more efficiently, ergo with > less energy. I was mostly joking about this - don't worry :-) > Well, either > that, or rely on the kernel to trap unimplemented SSE2 instructions > and emulate them in software. This is theoretically possible but I'm > pretty sure neither Linux nor Windows implement it. <aside> Even VMWare aren't doing this. However, it's now relatively common to have the CPU lie about the true capabilities of its instruction set (by faking the return from CPUID, which in Linux means that /proc/cpuinfo flags doesn't give the true picture). This is done so that guests can be migrated across machines in a cluser which have different capabilities. VMWare called this 'EVC clustering'. </aside> > To finish: I'm still very interested in hearing from packagers. Does > Debian, for example, already have some packages that are SSE2-only? > Are these packages specially tagged so that the installer will refuse > to install them on pre-SSE2 hardware? What's the party line? >From the Fedora p.o.v., there's no problem. We'll just deprecate OCaml on ancient pre-SSE2 hardware (for new distributions - they can keep using RHEL 5 on older hardware). Rich. -- Richard Jones Red Hat