Intel Fortran compiler

[Mark Hahn]

> Celeron 466, with RH 7.1, kernel 2.4.3.

so g77 was one of RH's funky "2.96+" snapshots?

> g77 (gnu compiler) time:  2:45 minutes
> ifc (intel compiler) time:     1:37 minutes
> 
> g77 options: -O2 -mpentiumpro -funroll-all-loops

I find that -funrill-all-loops usually gives *worse* performance.
in fact, -Os is the most commonly-recommended flag on the gcc dev list.
-fomit-frame-pointer is an obvious other one.