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Date: Mon, 11 Aug 2003 06:38:30 +0100
From: Jamie Lokier <jamie@shareable.org>
To: Willy Tarreau <willy@w.ods.org>
Cc: Albert Cahalan <albert@users.sourceforge.net>,
       linux-kernel mailing list <linux-kernel@vger.kernel.org>,
       davem@redhat.com, chip@pobox.com
Subject: Re: [PATCH] 2.4.22pre10: {,un}likely_p() macros for pointers
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Willy Tarreau wrote:
> It may well be when you use it in boolean constructs. The following functions
> return exactly the same result with different code :
> 
> int test1(int u, int v, int x, int y) {
>    return (u > v) || (x > y);
> }
> 
> int test2(int u, int v, int x, int y) {
>    return !!(u > v) | !!(x > y);
> }

Yes, it sounds familiar.  Although my code was not as contrived :) it
was from a real program.  Also, try "x != 0" instead of "!!x" and see
if you get different results.

-- Jamie