🚀 go-pugleaf

   To: help-gcc@prep.ai.mit.edu
   Date: 27 Nov 92 02:29:01 GMT
   Organization: University of Limerick, Ireland
   From: creedonn@ul.ie
   Reply-To: creedonn@ul.ie
   Subject: GNU CC port to the Motorola 88000
   
   Just how *good* is the code generator/optimiser in GCC?
   
Very good--I don't know any compiler that can consisently beat it on
any platform.

   I'm doing a 1 year Master's course in the University of Limerick, Ireland,
   and my project is to port GCC to the Motorola 88100 RISC processor.
   However, I now see that it has already been done, and from what I can
   gather by reading the documentation, it has been done quite well.
   
   My questions are then:
   
   Can I (not knowing very much about compilers now) reasonably expect to
   improve on what's there already within the 9 months before I finish this
   course?
   
Look at gcc/PROJECTS.  If you find something there that interests you,
try it out!  I think that GCC is much better at integer codes than
floating point codes (relative to other compilers).  You might
investigate why this is (1 month), scope out what it would take to
make improvements (1 month), and then start working (6 months).  I
wrote the first version of the GNU instruction scheduler as part of a
6-week class project at Stanford.  It managed to improve performance
in some cases (better pipeline scheduling on the SPARC) and hurt
performance in others (not enough registers to hold all the values
made live as a result of pipeline scheduling).

   Where can I find more detailed documentation on the port to the m88k? (
   And how much will it cost for that documentation? )
   
I don't believe there is any specific info on the port to the m88k,
but the code is reasonably well documented (ie, theory of operation,
implementation decisions).  I can send you a copy of my instruction
scheduling paper.

   How much rewriting/fine-tuning of the whole compiler (not just the code-
   generator/optimiser) would be necessary?

Depends on the project, of course.
   
   Any help or information would be much appreciated.
   Yours,
   Niall Creedon.
   [Didn't Michael Meissner do that port?  Perhaps he can comment. -John]

Actually I did the original port.  Meissner worked on it after me, and
Tom Wood (at Data General) currently maintains it.

   -- 
   Send compilers articles to compilers@iecc.cambridge.ma.us or
   {ima | spdcc | world}!iecc!compilers.  Meta-mail to compilers-request.

Michael