2009/9/25 Jussi Lehtola <jussilehtola(a)fedoraproject.org>:
On Fri, 2009-09-25 at 16:30 +0100, Jonathan Underwood wrote:
> Well, my point was that packages that do respect CFLAGS get built
> currently with certain options, and however Atlas builds, the default
> package should have comparable options. On x86, I see that is
> presently -march=i686 -mtune=atom, and IIRC -march=i686 implies sse
> and sse2 (not sure about sse3). Anyway, whatever it implies, I think
> that should be the default for the main Atlas package too.
No, -march=i686 does not use SSE; excerpt from gcc man page:
i686 Same as "generic", but when used as "march" option, PentiumPro
instruction set will be used, so the code will run on all i686
family chips.
Ah, right, thanks. Then I am advocating that Atlas be built without
SSE for the main package (option 1 of Deji's proposals, I think).