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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