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From: compilers@ima.UUCP
Newsgroups: mod.compilers
Subject: Re: Successful compilers for segment
Message-ID: <136300020@ima.UUCP>
Date: Mon, 6-Jan-86 22:13:00 EST
Article-I.D.: ima.136300020
Posted: Mon Jan  6 22:13:00 1986
Date-Received: Wed, 8-Jan-86 02:42:55 EST
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Approved: compilers@ima.uucp
Nf-ID: #N:ima:136300020:000:1151
Nf-From: ima!compilers    Jan  6 22:13:00 1986


[from cej at IHNP4/PTSFA/WELL (Craig Jackson)]

You cannot produce a 'good' compiler for a segmented architecture for a
language that has unbridled pointers, such as C.  C comes with the built-in
assumption that addresses are mappable onto the integers.  Other languages
with this problem include PL/I and to a certain extent, FORTRAN.  On the
other hand, more disciplined languages such as Pascal have little trouble
being implemented on segmented architectures.  Witness UCSD Pascal: the
original implementation was done for the segmented architecture of a
Burroughs B6700.  The micro one came along because the mainframe was too slow.
-- 
Craig Jackson
UUCP: {ihnp4!linus,seismo!harvard}!axiom!mhis!dricej
      {dual,ptsfa,lll-crg,hplabs}!well!cej
BIX:  cjackson

[Good point, but if the mainframe was so slow perhaps they didn't deal
so well with segments after all.  In any event, Pascal as defined by J+W or
by ISO doesn't seem to me to be very good for doing things like mapping a
file into a segment and then doing useful things to it there.  PL/I at least
has area variables and offset pointers which are relative to areas.  -John]
--------