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Date: Sat, 17 Mar 2007 21:04:40 +0100
From: Christoph Mallon <christoph.mallon@gmx.de>
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To: Max Laier <max@love2party.net>
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Cc: cvs-src@freebsd.org, Jeff Roberson <jeff@freebsd.org>,
	src-committers@freebsd.org, cvs-all@freebsd.org
Subject: Re: cvs commit: src/sys/kern sched_ule.c
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Max Laier schrieb:
> On Saturday 17 March 2007 20:09, Jeff Roberson wrote:
>> Any language lawyers care to comment on this?
> 
> I find this strange.  According to the spec "(Decrementing is equivalent 
> to subtracting 1.)", but "pri = --pri % RQ_NQS;" will behave like you 
> expect, while "pri = (pri - 1) % RQ_NQS;" clearly didn't.

"pri = --pri % RQ_NQS;" modifies "pri" twice between two sequence 
points. According to the C standard this causes undefined behaviour!