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From: Jamie Lokier <jamie@shareable.org>
To: Albert Cahalan <albert@users.sourceforge.net>
Cc: Andrew Morton OSDL <akpm@osdl.org>,
	willy@w.ods.org, chip@pobox.com,
	linux-kernel mailing list <linux-kernel@vger.kernel.org>,
	davem@redhat.com
Subject: Re: [PATCH] 2.4.22pre10: {,un}likely_p() macros for pointers
Date: Wed, 13 Aug 2003 20:42:01 +0100	[thread overview]
Message-ID: <20030813194201.GG4405@mail.jlokier.co.uk> (raw)
In-Reply-To: <1060643637.949.228.camel@cube>

Albert Cahalan wrote:
> > Being a simple soul, I prefer __builtin_expect((x) != 0, 1).
> 
> That's much harder to read. The !! is a nice
> neat idiom. The other way requires a bit of thought.
> (is that == or !=, a 0 or 1, and what does that
> compute to?)
> 
> The !! is visually distinctive. It has only one use.
> When you see it, you instantly know that a value is
> being converted to the pure boolean form.

Dear Albert,

I have to tell you your are totally wrong :)

Most C programmers will find "!!x" less clear than "x != 0", simply
because "!!x" isn't used all that much.

If you require significant thought to parse "x != 0" you are going to
have trouble with more complex idioms.

Like "x && 1" and "x || 0", which are obvious to anyone :)

-- Jamie

  reply	other threads:[~2003-08-13 19:43 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-08-10  4:03 [PATCH] 2.4.22pre10: {,un}likely_p() macros for pointers Albert Cahalan
2003-08-10  7:29 ` Willy Tarreau
2003-08-10  8:02   ` Willy Tarreau
2003-08-11  1:23   ` Chip Salzenberg
2003-08-11  2:09     ` Jamie Lokier
2003-08-11  2:39       ` Chip Salzenberg
2003-08-11  4:02         ` Albert Cahalan
2003-08-11  4:30         ` Jamie Lokier
2003-08-11  5:30         ` Willy Tarreau
2003-08-11  5:42           ` Jamie Lokier
2003-08-11 13:09             ` Albert Cahalan
2003-08-11 18:55               ` Andrew Morton
2003-08-11 23:13                 ` Albert Cahalan
2003-08-13 19:42                   ` Jamie Lokier [this message]
2003-08-11  4:55   ` Jamie Lokier
2003-08-11  5:26     ` Willy Tarreau
2003-08-11  5:38       ` Jamie Lokier
  -- strict thread matches above, loose matches on Subject: below --
2003-08-05 12:44 Albert Cahalan
2003-08-09  0:21 ` Jamie Lokier
2003-08-09  8:13   ` Willy Tarreau
2003-08-09  8:51     ` David S. Miller
2003-08-09  9:36       ` Jamie Lokier
2003-08-09 10:10       ` Herbert Xu
2003-08-09 10:42       ` Alan Cox
2003-08-09 16:23         ` Jamie Lokier
2003-08-04 17:06 Chip Salzenberg

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