From: J DOT Bischoff AT airbus DOT dasa DOT de
Message-Id: <9711211002.AA15293@axe.bre.da>
Subject: Re: g77 problems
To: ghubbar AT sandia DOT gov
Date: Fri, 21 Nov 1997 11:02:38 MET
Cc: djgpp AT delorie DOT com
In-Reply-To: <34746CAC.427@sandia.gov>; from "Gary Hubbard" at Nov 20, 97 9:00 am
Precedence: bulk

Hi, Gary,

I made the following experience with g77 under Unix:
If there is no DATA statement the size of both executables (compiled
with / without "-fno-automatic") is almost the same (only the size
of the text segments is slightly different).
With each variable that is initialized by a DATA statement the size
of the executables grows. 
So the linker seems to be intelligent enough to allocate the appropriate
memory at run time when it is possible.
I don't know whether or not the DJGPP-linker shows the same bahaviour.
 
Jens


> 
>     Second, and more important is the executable size.  As with
> many fortran programs, I need to compile with a -fno-automatic
> option.  Since there is no recursion, this is no real limitation,
> except that the executable size grows proportionally with the
> runtime size.  Shouldn't the storage go in a .bss section, which
> is created and zeroed at load time, or does DPMI prevent this
> somehow.  Loading a 30MB file off the disk is just too slow.  I
> seem to remember seeing a gzip based loader which would probably
> help, but the link step would still be very slow.  Is there a way
> to avoid storing all the zero bytes on the disk
> 
> Thanks,
> 	Gary
> 


--
|      |      | Jens Bischoff   |   Daimler-Benz Aerospace Airbus |
|   --<O>--   +-----------------+---------------------------------+
|      |      | Aerodynamic Data Department (EFD)                 |
| Dasa Airbus | Huenefeldstrasse 1-5     D-28199 Bremen (Germany) |