Wanted: Ultra-fast fortran compiler for UNIX
Douglas J Freyburger
doug at escher.UUCP
Sun Jul 28 10:38:51 AEST 1985
> >Can anyone point to a company that supplies a UNIX Fortran compiler which
> >executes much faster than f77 (say, on par with the VMS compilers or better)?
>
> Actually there is limited room for improvement. The 4.2BSD compiler is
> considerably better than the original f77 in that respect. Published
> work (by Jack Dongarra at Argonne National Laboratory
> [dongarra at anl-mcs]) shows about 25-30% slower runtimes for the 4.2BSD
> compiler over the VMS 4.1 compiler, for dense linear algebra. I've
> also coded some sparse linear algebra (essentially Yalepack) in
> assembly and found only 30-35% speed up. Let's give credit where
> credit is due!
>
I'm sorry, but I have troubles giving credit to a compiler
that is fully 30% slower than a competitors compiler for the
same machine architecture in the same language. Does going
from blind translation into assembler really cost 30% more
execution time? I always thought that good optimization was
less than that. Does the Berkeley compiler do no
loop-invarient migration, common expression elimination or
ANYTHING? It is true that DEC worked very hard optimizing
its ForTran's output, but 30%? I haven't done ForTran work
on any on my unix machines yet, just C and Pascal, and this
makes me pretty happy about it.
Now I really understand the motivation behind the original
posting. The only one I know about for unix is Green
Hills. They have C, Pascal, ForTran (and P/LM?) for
assorted machines especially unix VAXen.
Doug Freyburger DOUG at JPL-VLSI, DOUG at JPL-ROBOTICS
JPL 171-235 ...escher!doug, doug at aerospace
Pasadena, CA 91106 etc.
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