Path: utzoo!attcan!uunet!cbmvax!jesup
From: jesup@cbmvax.UUCP (Randell Jesup)
Newsgroups: comp.arch
Subject: Re: Branch Delay Annullment
Message-ID: <4053@cbmvax.UUCP>
Date: 17 Jun 88 21:06:37 GMT
References: <22065@amdcad.AMD.COM> <12211@apple.Apple.COM> <27527@pyramid.pyramid.com> <12300@apple.Apple.COM>
Reply-To: jesup@cbmvax.UUCP (Randell Jesup)
Organization: Commodore Technology, West Chester, PA
Lines: 22

In article <12300@apple.Apple.COM> baum@apple.UUCP (Allen Baum) writes:
>Oops. Its been so long since I've looked at this that I forgot about a second 
>part of the argument. You're absolutely right that there is a lot of code of
>the form:     If (error-condition( {handle it};  and that this code is executed
>infrequently. If this is the case, it would pay to have this code be executed
>out of line; that is, you would like to branch to it, and then branch back
>to the main line code. The most frequently executed code is then straight-line,
>a real win in situtations where you benefit from bust mode i-fetches. 

	I don't know about you, but I tend to write code that looks more
like:
	if (!error) {
		...
	} [else { ... }]

	Especially useful when doing resource allocations, like "if (!(ptr =
(struct ptr *) malloc(xyzzy))) { use ptr } else { return error }".

	It comes down to both the type of application and the individual
coding style (and of course language).

Randell Jesup, Commodore Engineering {uunet|rutgers|ihnp4|allegra}!cbmvax!jesup