Re: [PATCH] 2.4.21-rc1 pointless IDE noise reduction

From: Willy Tarreau <willy@w.ods.org>
To: Timothy Miller <miller@techsource.com>
Cc: root@chaos.analogic.com, Chuck Ebbert <76306.1226@compuserve.com>,
	Jens Axboe <axboe@suse.de>,
	linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] 2.4.21-rc1 pointless IDE noise reduction
Date: Thu, 24 Apr 2003 20:27:56 +0200	[thread overview]
Message-ID: <20030424182756.GA19290@alpha.home.local> (raw)
In-Reply-To: <3EA81BBB.3020709@techsource.com>

Hi !

Well, although I usually don't like these endless coding-style threads, why
don't you simply use this common form ? :

    return !!(foo & MASK);

I found that the compilers like it much and easily emit conditionnal set
instructions. Eg, on x86, this should be something like :

   testl MASK, foo
   setnz retcode

Cheers,
Willy

On Thu, Apr 24, 2003 at 01:15:39PM -0400, Timothy Miller wrote:
> >
> >
> >I meant return ((foo & MASK) && 1);
> >
> >Try it, you'll like it! No shifts, no jumps.
> >
> > 
> >
> 
> Looks sweet!  If the compiler is smart, that is.  I'll add that to my 
> repetoire.  I'll have to see what the asm output looks like.