Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!ucsd!nosc!crash!pnet01!jca
From: jca@pnet01.cts.com (John C. Archambeau)
Newsgroups: comp.os.minix
Subject: C compilers and large code/data...
Message-ID: <1609@crash.cts.com>
Date: 22 Feb 90 04:56:46 GMT
Sender: root@crash.cts.com
Organization: People-Net [pnet01], El Cajon CA
Lines: 42

The problem isn't the fact that we need a C compiler with source per se for PC
Minix, it's the fact that we have a real pain in the gulliver of an
architecture to work from with respect to memory management.  I'm one of the
people around here that would LOVE to see a large model C compiler for PC
Minix, but the problem is that PC Minix is only aware of tiny (64k) and small
(64K code/64K data) memory models.  If one wants a large model C compiler, one
first must modify the memory management scheme of Minix to accommodate the
juggling of multiple segments for code and/or data.  It's not JUST an "I need
to port a C compiler" problem.  It can be done, but very painfully.  There are
also some ways around it by faking virtual memory (via LIM EMS 4.0 or actual
swapping).  I don't expect to see any large model C compilers or PC Minix
supporting large model programs till a 386 version is out (what's the status
on that Mr. Evans?) with an appropriate memory management scheme.  GCC has
been ported to the 386 environment, so it's now a matter of Minix being
hammered into a 386 memory management scheme.  The 286 is brain damaged, but
one could try to attempt large model programs with it, but those of us who
have used a Unix based OS on a 286 and 386 know hands down that the 386 is
better suited for it.

I am no compiler expert by any means, but I have taken a compiler construction
course and I do know the pains in writing a compiler and I do know that
getting one to fit in a small memory model is a very meticulous and
painstaking process.  The PC Minix compiler wasn't even developed on an IBM PC
to begin with, but a much larger machine.  I do know that the Amsterdam
Compiler Kit is available for Sun Workstations since I have seen it in the Sun
Catalyst.  If you want to develop a compiler for PC Minix, you'd have to cross
compile it from MS-DOS or another operating system to get the job done.  Minix
C just can't handle that big of a job.

That's my little bit on the C compiler matter.  I may not like its performance
and what it can do, but it is better than no compiler at all.
 
     // JCA

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