From: keryell@ens.fr (Ronan Keryell)
Subject: Re: motorola 88k for SIMD machine ?
Keywords: parallelism,architecture,SIMD,POMP,data parallel language,POMPC
Reply-To: keryell@ens.fr
Organization: Laboratoire d'Informatique de l'Ecole Normale Supe'rieure, Paris, France
Date: Sun, 11 Oct 92 20:51:07 GMT

>nearly nobody speaks about 88k from Motorola although it is very much used
>(e.g. 50,000,000 units contract with Ford). Is it possible to build a SIMD
>machine with it ?

>Klaus H.Wolf
>wolf@sun1.ruf.uni-freiburg.de

Yes, I think it is a good idea to use such a processor in a SIMD machine
because it is :
- Harvard without internal cache,
- a 32-bit processor so you can use the implicit parallelism in the 32-bit data
	coding :-) (I mean that since you usually compute on such data, it is faster
	with 32-bit processors).

I defended my PhD thesis on the POMP project last week and it is about a SIMD computer
built with 88100s (what a coincidence...).
The prototype is not finished yet but with 256+1 88100s we can hope 2 GFLOPS and
23 GFLOPS/m3.

Abstract :

Parallelism is an efficient and cost-effective way to build
powerful computers beyond the improvement of the components speed.\\
The data parallelism is an especially interesting class of parallelism
since it is the natural parallelism of most numerical computation problems
which deal with big sets of data.\\
With this point of view we present a Small Massively Parallel SIMD Computer
(POMP in French) with good performance but in a small volume yet.\\
Although SIMD computers usually imply the development of a custom processor,
we propound the perversion of an off-the-shelf RISC processor for the
parallel processors and a VLIW coupling with the scalar processor in
order to reach our goals.\\
A C-based parallel language (POMPC) is presented to express the
explicit data-parallelism of programs.\\
A compilation process allows us to use the programming environment of
the chosen processor but we can also compile POMPC for other parallel
computers (CM-2, MP-1, iPSC/860) or a workstation for simulation.\\
New SIMD flow control methods are developed to improve SIMD tests
efficiency.\\
Then, a new static{}/{}hybrid network is used for its
cost-effectiveness and a possible LCA implementation.\\
An SPMD partitionable extension of the machine
is studied to compare the GFLOPS{}/{}cubic meter ratio of the two
approaches.\\
At last, two applications from the physics domain written in POMPC
are shown.



The reference of the PhD report is :
@phdthesis{these:keryell,
    author = {Ronan Keryell},
    type = nouvelle_these,
    title = {POMP : d'un Petit Ordinateur Massivement Paralle`le SIMD a` Base
    de Processeurs RISC --- Concepts, Etude et Re'alisation},
    school = {Laboratoire d'Informatique de l'Ecole
    Normale Supe'rieure --- Universite' Paris XI},
    year = 1992,
    month = oct,
    }

The report is written in French (scientific French is rather similar to
scientific English :-)...) but you can see also :

on the project (it is a bit old) :
@conference{POMP_PARLE,
    author = {Philippe Hoogvorst and Ronan Keryell and Philippe Matherat
        and Nicolas Paris},
    title = {POMP or How to Design a Massively Parallel Machine with Small
        Developments},
    booktitle = {PARLE '91 Parallel Architectures and Languages Europe},
    pages = "83-100",
    publisher = {Springer-Verlag},
    organization = {Lecture Notes in Couputer Science},
    volume = {505(I)},
    month = jun,
    year = 1991
    }

and on the POMPC language specification :
@techreport{rap:pompc1.99_anglais,
        author = {Nicolas Paris},
        title = {Definition of POMPC (Version 1.99)},
        number = {LIENS-92-5-bis},
        note = {\recuperableftp{spi.ens.fr} dans le fichier
            {\tt pub/reports/liens/liens-92-5-bis.A4.ps.Z}},
        month = mar,
        institution = liens,
        year = 1992
    }
    
I can send all these reports by mail on request or you can get by anonymous ftp on spi.ens.fr in the files pub/reports/liens/liens-91-5.A4.ps.Z and 
pub/reports/liens/liens-92-5-bis.A4.ps.Z for the 2 last.

In the directory pub/pompc you can get a prototype of the POMPC compiler for
Sun4 (SIMD simulation, i.e. sequential execution), CM-2 and MP-1, with some
samples of programs. Other examples can be found in the pub/pomp directory.

-----------------------------------------------------------------------------
    Ronan KERYELL
    Laboratoire d'Informatique de l'Ecole Normale Supe'rieure / URA 1327 CNRS
    45, rue d'Ulm
    75005 PARIS FRANCE
    Tel: (+33 1) 44.32.20.32
    Fax: (+33 1) 44.32.20.80
    E-mail:  Ronan.Keryell@ens.fr