linux-kernel - Re: The type of bitops

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Date:	Mon, 06 May 2013 18:36:32 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
CC:	linux-arch <linux-arch@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: The type of bitops

On 05/06/2013 05:51 PM, Linus Torvalds wrote:
> 
>> 4. Do some macro hacks so the bitops are dependent on the size of the
>>    argument.
> 
> That sounds insane. Just *how* could the size of the argument even
> matter? Seriously, there's no *difference* between a 32-bit or a
> 64-bit index. The code is the same, there's no possible reason to make
> it be different.
> 

The only reason on x86 would be to avoid the REX prefix.  Hardly worth
it, though.

	-hpa

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