On Mon, Dec 8, 2008 at 12:51 PM, Clint Whaley <[EMAIL PROTECTED]> wrote: > William, > >>Is there an easy way to build an ATLAS but without it using any sse >>(or other "modern") optimizations? >> >>See the little discussion below. The main issue is that I want to be >>able to build a binary on a Xeon box that will work on an old Athlon >>box. I have a 32-bit Linux OS installed on the Xeon box. > > First off, this is a *bad* idea (unfortunately, one everyone seems to want > to do :); A Xeon-tuned library will be very poorly optimized for an Athlon.
There are very very few users who will use this version of Sage. In fact, they are *only* people whose current performance is 0, because they can't build/use Sage at all. So I guess terrible is a lot faster than 0. :-) > However, if you insist on crippling my performance, it may be possible: > you will need to add the flags telling gcc not to add any SSE instructions > to all compiler flags, using the configure command as described: > > http://math-atlas.sourceforge.net/atlas_install/atlas_install.html#SECTION00042000000000000000 > > Then, passing -V 0 to configure will tell ATLAS to not use any vector > extensions itself. > > Like I say, this might work, but it will be a terrible Athlon library. You > will probably drop your performance by a third or half by doing this . . . I think the only other option for us would be to use GSL's cblas, which would drop performance by at least a factor of 10, and be a major pain to maintain too. Thanks! -- William --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to sage-devel@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/sage-devel URLs: http://www.sagemath.org -~----------~----~----~----~------~----~------~--~---
