Message-ID: <45BA3F42.3020006@zytor.com>
Date: Fri, 26 Jan 2007 09:49:54 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
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To: eranian@hpl.hp.com
CC: linux-kernel@vger.kernel.org
Subject: Re: i386 and x86-64 bitops function prototypes differ
References: <20070126143555.GL11525@frankl.hpl.hp.com>
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Stephane Eranian wrote:
> Hello,
> 
> I ran into compiler warnings with the perfmon code when I tried
> using test() and __set_bit() on i386. 
> 
> For some reason, the i386 bitops functions use unsigned long * for
> the address whereas x86-64/ia64 use void *.
> 
> I do not quite understand why such difference?
> Is this just for historical reasons?
> 
> Thanks.
> 

Arguably void * is the right thing for a littleendian architecture.  For 
bigendian architectures it unfortunately matters what the chunk size is, 
regardless of if the chunks are numbered in bigendian (reverse) or 
littleendian (forward) order.

	-hpa
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