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From: quiroz@rochester.UUCP (Cesar Quiroz)
Newsgroups: net.lang.c
Subject: Re: C language hacking
Message-ID: <3323@rochester.UUCP>
Date: Mon, 12-Nov-84 10:10:53 EST
Article-I.D.: rocheste.3323
Posted: Mon Nov 12 10:10:53 1984
Date-Received: Tue, 13-Nov-84 01:32:44 EST
References: <5715@brl-tgr.ARPA>
Distribution: net
Organization: U. of Rochester, CS Dept.
Lines: 30

>(from a recent posting :) 
> I find that frequently I need both the quotient and remainder of
> two integers:	a / b	a % b
> Since most (maybe all) machine architectures compute these at the
> same time, it sure would be nice to be able to get both results
> rather than wastefully reexecuting precisely the same instructions
> a second time.  This becomes particularly bothersome when "a" & "b"
> are fairly complicated expressions.  I have no idea what a good
> syntax for such an operation would be.
> 
> It would also be nice if sin( x ) and cos( x ) could be computed
> simultaneously with reduced cost.  I doubt if this is possible
> but would like to know if it is.

Both are reasonable expectations, but seem to have a place in a standard
library rather than in the syntax of the language.  

The sin/cos simultaneous computing is something you can  program in C
completely.  Getting both quotient and remainder at the same time cannot
(at least not without incurring a procedure call, which denies the
advantage) and you may have a point if you expect the compiler to 
recognize something like:

intdiv(a,b,&q,&r);

and expand it in line.  However, it may be too much additional overhead
for the gains.  In such a case, you may feel forced to write assem...
(no I didn't mean to type that!).

Cesar