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From: bobmon@iucs.UUCP
Newsgroups: comp.misc
Subject: Re: Assembly Language
Message-ID: <4650@iucs.UUCP>
Date: Fri, 14-Aug-87 21:59:14 EDT
Article-I.D.: iucs.4650
Posted: Fri Aug 14 21:59:14 1987
Date-Received: Sun, 16-Aug-87 09:10:25 EDT
References: <892@edge.UUCP> <2840@phri.UUCP>
Reply-To: bobmon@iucs.UUCP (RAMontante [condition that I not be identified])
Organization: Indiana University, Bloomington
Lines: 35

In article <2840@phri.UUCP> roy@phri.UUCP (Roy Smith) writes:
>
>	My experience has been that most assembler code has one comment
>per statement, often not very useful at that.  A typical example might be:
>
>	add	r1, r2		; add r1 to r2, leave result in r2
>	cmp	r2, r0		; is r2 greater than r0?
>	bge	skip1		; if no....
>	mov	r0, -(sp)	; push r0 onto the stack
>	bra	skip2		; if yes...
>skip1:	mov	r2, -(sp)	; push r2 onto the stack
>skip2:	jsr	foo		; call subroutine foo
>
>	Of course, this is not to say that there aren't assembler
>programmers who comment the algorithm instead of translating the opcodes
>into english, but they seem rare.  In fact, I would guess that in most
>assembler courses (are there any of these anymore?) the above code would
>get a positive nod from the instructor because every line had a comment,
>just like it is supposed to.

Sorry, I hafta defend my honor here.  I'm a grad student, I just (today!)
finished teaching an undergraduate assembly-language course.  Actually it's
called "Computer Structures", but it's centered on the machine language.

I've gone to the point of public ridicule to discourage the "add memory to
register" style of comments.  I specifically said that I preferred a block
of comments about a subroutine to line-by-line comments.  I told them that
the comments should tell me WHY, not WHAT.  I told them to write the kind of
comments they would want to read if they had to debug their own code in
6 months.

Yes, it works.  At least, for some of them.  I give grades to distinguish
between those who pick up good techniques and those who don't.  Wanna see
some well-commented assembly code?  Wanna hire one of my brighter kids?
(They even use metric units...)