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From: Michael Tokarev <mjt@tls.msk.ru>
To: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] embarassing typo
Date: Wed, 30 Mar 2005 01:58:57 +0400	[thread overview]
Message-ID: <4249CFA1.7050907@tls.msk.ru> (raw)
In-Reply-To: <yw1xd5ti17z6.fsf@ford.inprovide.com>

Måns Rullgård wrote:
> "Ronald S. Bultje" <rbultje@ronald.bitfreak.net> writes:
> 
>>--- linux-2.6.5/drivers/media/video/zr36050.c.old	16 Sep 2004 22:53:27 -0000	1.2
>>+++ linux-2.6.5/drivers/media/video/zr36050.c	29 Mar 2005 20:30:23 -0000
>>@@ -419,7 +419,7 @@
>> 	dri_data[2] = 0x00;
>> 	dri_data[3] = 0x04;
>> 	dri_data[4] = ptr->dri >> 8;
>>-	dri_data[5] = ptr->dri * 0xff;
>>+	dri_data[5] = ptr->dri & 0xff;
> 
> Hey, that's a nice obfuscation of a simple negation.

It's not a negation.  This statement always assigns zero to
dri_data[5] if dri_data is char[].  Looks like gcc isn't catching
this problem.

> BTW, when assigning to a char type, is the masking really necessary at
> all?  I can't see that it should make a difference.  Am I missing
> something subtle?

Well, it's a matter of readability mostly.  For now at least, when
char is always 8 bytes...

/mjt

  reply	other threads:[~2005-03-29 21:59 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-03-29 20:36 [PATCH] embarassing typo Ronald S. Bultje
2005-03-29 21:02 ` Måns Rullgård
2005-03-29 21:58   ` Michael Tokarev [this message]
2005-03-30  1:40     ` Dmitry Torokhov
2005-03-30  5:53       ` Gene Heskett
2005-03-30 23:38         ` John Pearson
2005-03-31  4:16           ` Gene Heskett
2005-03-30  2:07     ` Måns Rullgård
2005-03-30  3:34       ` Phil Howard
  -- strict thread matches above, loose matches on Subject: below --
2005-03-29 23:31 Vicente Feito
2005-03-30  3:35 ` Måns Rullgård

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