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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.works
Subject: Re: Not again!?  Assembler vs High-Level languages
Message-ID: <5478@utzoo.UUCP>
Date: Sat, 13-Apr-85 19:52:26 EST
Article-I.D.: utzoo.5478
Posted: Sat Apr 13 19:52:26 1985
Date-Received: Sat, 13-Apr-85 19:52:26 EST
References: <483@terak.UUCP> <2251@wateng.UUCP> <492@terak.UUCP>, <3278@utah-cs.UUCP>, <1002@ecsvax.UUCP>
Organization: U of Toronto Zoology
Lines: 23

> How can any language (I don't know BLISS) produce a smaller program
> than does assembler (assuming a competent assembly programmer)?  I'm
> more interested in HOW than in a discussion of how many
> competent programmers there are.

Because producing really tight code is an essentially mechanical job,
requiring complex bookkeeping and application of many special tricks.
Programs are much better at this than human beings.  My recollection
is that a human assembler programmer could, given a lot of work, get
code comparable to that of the Bliss compilers for any given small
piece of code.  But the amount of work involved is prohibitive for any
substantial program.

Remember, we are not talking run-of-the-mill assembler programming here,
we are talking serious crunch-the-last-bit maximum-use-of-every-register
efforts.  Mundane compilers generally do not do as well as good human
assembler programmers, since the human programmer applies the simpler
sorts of optimizations routinely.  But real optimizing compilers put
more work into every piece of code than a human programmer can afford
for anything but the most crucial stuff.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry