[Pw_forum] AMD64 and IFC

[Serguei Patchkovskii]

On Fri, 30 Jan 2004, Paolo Giannozzi wrote:

> I have heard that you can compile 32-bit executables with Intel
> compilers, but it is not very fast,

Take a look at AMD SPECfp2000 submissions for opterons - ifc
and pgf submissions for the same system are within a few percent
of each other - sometimes ifc wins; sometimes pgf wins. This is
despite the fact that ifc does not know about AMD64 as such, and
can use only half of the FP registers available to pgf.

If you look at the individual tests for Opteron 148, for example,
you'll see that ifc generates faster code for 6 of those (swim,
art, equake, ammp, lucas, apsi), while pgf is faster for 8 (wupwise,
mgrid, applu, mesa, galgel, facerec, fma3d, sixtrack) - but none
of the wins are particularly dramatic.

This also tallies pretty well with my experience - ifc 7.1 and
pgf90 5.0-2 are about neck-to-neck on opterons.

> and that the only compiler that compiles 64-bit code on AMD
> is PGI.

There is also Pathscale (http://www.pathscale.com/) - if you are
one of the few lucky people on their beta-testing program.

Serguei

---
Dr. Serguei Patchkovskii

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