Jarrod Millman wrote:
On Sat, Nov 1, 2008 at 1:07 AM, Robert Kern
wrote:
Hi,
On Fri, Oct 31, 2008 at 05:25, David Cournapeau
wrote: I was wondering whether it was really worth having a lot of magic going on in fcompilers for flags like -msse2 and co (everything done in get_flags_arch, for example). It is quite fragile (we had several problems wrt buggy compilers, buggy CPU detection), and I am not sure it buys us much anyway. Did some people notice a difference between gfortran -O3 -msse2 and gfortran -O3 ? You're probably right.
we removed setting the various SSE flags in Sage's numpy install because they caused segfaults when using gfortran. I don't think that there is a significant performance difference with SSE for that code because we use Lapack and ATLAS build with SSE when it is available.
I think it is probably best to take out some of the magic in fcompilers as well.
Cheers, Michael