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Path: utzoo!utcsri!flaps
From: flaps@utcsri.UUCP (Alan J Rosenthal)
Newsgroups: comp.lang.c
Subject: Re: Available No. of Registers
Message-ID: <4141@utcsri.UUCP>
Date: Sat, 14-Feb-87 01:19:57 EST
Article-I.D.: utcsri.4141
Posted: Sat Feb 14 01:19:57 1987
Date-Received: Sat, 14-Feb-87 02:35:51 EST
References: <3950004@nucsrl.UUCP> <83@ucdavis.UUCP> <2250@jade.BERKELEY.EDU> <805@celerity.UUCP> <12982@sun.uucp> <873@celerity.UUCP>
Reply-To: flaps@utcsri.UUCP (Alan J Rosenthal)
Organization: University of Toronto
Lines: 33
Summary: 


In article <873@celerity.UUCP> jjw@celerity.UUCP (Jim (JJ) Whelan) writes:
>K&R's suggestion that the register variables are assigned to registers in
>order of appearance solves my problem -- I just put the variables in order
>of importance and let the compilers handle it from there.

Unfortunately, this is not sufficient in the case of register formals.
Consider something like:

	f(n)
	register int n;
	{
	    register int i;

where it is considered more useful to put 'i' in a register than 'n'.  It
is not possible to arrange the declarations in the appropriate order, and

	f(nformal)
	int nformal;
	{
		register int i,n = nformal;

, which is often recommended, wastes an int on all machines.

-- 

Alan J Rosenthal

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