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From: cooper%vlab.dec.com@decwrl.dec.com (g.d.cooper in the shadowlands)
Newsgroups: comp.realtime
Subject: Re: Searching for realtime languages
Message-ID: <2648@shlump.dec.com>
Date: 31 May 89 23:30:10 GMT
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Organization: DEC Advanced CI Development, Marlboro MA
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In article <8524@venera.isi.edu>, raveling@venera.isi.edu (Paul Raveling) writes...
>	These applications needed speed and didn't need more than
>	basic language features.  Typical PL/M-86 logic was around
>	a factor of 2 slower than typical hand-coded assembly language,
>	which is pretty decent on Intel's PISC (Perverse Instruction Set
>	Computer) architecture.

While I agree that PL/M isn't as good as hand-coded assembler where else will 
you get the message (I wish I could remember the exact wording):

..Instruction optimized out of existence...

Optimization for PL/M when I used it briefly (about '84 I think) ran from fair 
to excessive.  At the top end I would expect better performance than a factor 
of 2 (excluding proc call overhead).

>	Another might-have-been would be a variant of BLISS.  The
>	BLISS-11 compiler was the best I've seen so far at efficient
>	code generation, and the language was almost the right blend
>	of simplicity and capability.  Some details of syntax were
>	it's main problem -- probably the dilemma of "how many dots"
>	was the biggest.

Actually to get back to the original thrust of this thread,  BLISS-10 could be 
very accurately predicted as to code size.  Depending on the constructs, you 
could figure +/- 2 instructions as long as the code was not so convoluted as to 
give the optimizer time to play.
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