Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!decwrl!decvax!ucbvax!ucsd!sdcsvax!sdcc6!mplvax!cdl
From: cdl@mplvax.nosc.MIL (Carl Lowenstein)
Newsgroups: comp.lang.c
Subject: Re: Another way (How not to write a loop)
Message-ID: <722@mplvax.nosc.MIL>
Date: 19 Feb 88 04:11:42 GMT
References: <1988Feb11.200149.25172@sq.uucp> <2550046@hpisod2.HP.COM> <2150@bsu-cs.UUCP>
Reply-To: cdl@mplvax.nosc.mil.UUCP (Carl Lowenstein)
Organization: U.C. San Diego, Marine Physical Laboratory
Lines: 19

In article <2150@bsu-cs.UUCP> dhesi@bsu-cs.UUCP (Rahul Dhesi) writes:
>
>Floating point numbers should not be used for counting except when such
>use gains us a remarkable degree of badly-needed efficiency.  
>
>     count -=1;		/* integer arithmetic with software test */
>     if (count == 0)
>	abort_program;

This is inefficient?  I would hope that any decent compiler could turn
these lines into the something like (usual case one instruction):

			/ integer arithmetic with hardware test
	ISZ	COUNT	/ PDP-8 instruction, but even CISC's like
	JMP	ABORT	/  IBM 7090's and later have an equivalent

-- 
	carl lowenstein		marine physical lab	u.c. san diego
	{ihnp4|decvax|ucbvax}	!sdcsvax!mplvax!cdl