[comp.sys.amiga.programmer] Fortrann

James_Bowers@a68k.UUCP (James Bowers) (06/11/91)

That same old Fortran77 is still hanging on where I work and so I need to run
it on an amiga 3000.  1) absoft fortran seems to be the only commercial
program available. Right? 2) if this is in error who else has a complier? If
this is right, who of you use it? And how slow (fast) is it compared to
Fortran 77 on a VAX?  3) I have looked at the absoft fortran on the Macintosh
and have found it to be 5-6 times slower than the VAX fortran because the
compiler has to recompute each address in an array.  The VAX knowes where in
the array it was last and just increments to the next location. I imagine
that this is also the case with the Amiga version of fortran. Any comments,
corrections?  I need an optimizing compiler for the A3000 which does at least
2 times the run time speed of the final code compared to a VAX 11/780. 4) If
there is another source of fortran 77 for the Amiga please leave me a phone
number.  I would like to discuss your experience. If you would be willing to
call me I am at (303) 980-0070. ;) thanx Jim Bowers

peterm@am.dsir.govt.nz (Peter McGavin) (06/14/91)

>1) absoft fortran seems to be the only commercial program available. Right?

I don't know of any others.  There is at least 1 freely-distributable
FORTRAN, i.e, /amiga/languages/misc/BCF77.lzh on ab20.larc.nasa.gov.  There
is also f2c.

>How slow (fast) is it compared to Fortran 77 on a VAX?

I've only tried the non-pro version (no 68882 support) on an A3000.  It worked
for me and seemed fast, but I wasn't worried about speed at the time.  It
probably doesn't do much optimisation.  If you need speed, try f2c followed by
gcc with all the optimisations on.
--
Peter McGavin.   (srwmpnm@wnv.dsir.govt.nz  or  peterm@am.dsir.govt.nz)

swalton@corona.csun.edu (Stephen Walton) (06/15/91)

In article <PETERM.91Jun14111403@kea.am.dsir.govt.nz> peterm@am.dsir.govt.nz (Peter McGavin) writes:
>
>>How slow (fast) is it compared to Fortran 77 on a VAX?
>
>I've only tried the non-pro version (no 68882 support) on an A3000.  It worked
>for me and seemed fast, but I wasn't worried about speed at the time.  It
>probably doesn't do much optimisation

I've run one benchmark with Absoft F77, namely LINPACK.  On an A3000/25,
it came in at about 200 Kflops, about the same as a 25 MHz '386 machine
running under Microsoft Fortran.  [This is from memory, so don't hold me
to this.]  I don't know offhand what a VAX 11/780 does here.

The combination of f2c plus a C compiler may be somewhat faster, but is
also about a factor of 10 slower in going from the source to an executable.
-- 
Stephen Walton, Dept. of Physics & Astronomy, Cal State Univ. Northridge
    "Lately it occurs to me/What a long, strange trip it's been"