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From: Linus Torvalds <torvalds@linux-foundation.org>
To: David Howells <dhowells@redhat.com>
Cc: mingo@elte.hu, tglx@linutronix.de, linux-arch@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] X86: Optimise fls(), ffs() and fls64()
Date: Fri, 26 Mar 2010 10:45:05 -0700 (PDT)	[thread overview]
Message-ID: <alpine.LFD.2.00.1003261042580.3721@i5.linux-foundation.org> (raw)
In-Reply-To: <28287.1269625325@redhat.com>



On Fri, 26 Mar 2010, David Howells wrote:
> 
> Hmmm...  My ancient Borland Assembler dead-tree manual doesn't mention that.

I went back and checked the old Intel 386 docs from -92 or something, and 
it was "undefined" in there too. So at least Intel seems to have been very 
consistent on this.

That said, maybe all implementations actually do the "don't touch" thing. 

But I do have this memory of us doing this ten+ years ago, though, and 
having to check the ZF after all. Which is why I reacted to the patch in 
the first place and checked the documentation.

			Linus

  reply	other threads:[~2010-03-26 17:49 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <4BACCB4E.7010108@draigBrady.com>
2010-03-26 14:42 ` David Howells
2010-03-26 14:42   ` [PATCH 2/3] Adjust the comment on get_order() to describe the size==0 case David Howells
2010-03-26 14:42   ` [PATCH 3/3] Optimise get_order() David Howells
2010-03-26 17:23   ` [PATCH 1/3] X86: Optimise fls(), ffs() and fls64() Linus Torvalds
2010-03-26 17:37     ` Scott Lurndal
2010-03-26 17:42       ` Linus Torvalds
2010-04-06 13:57         ` Jamie Lokier
2010-04-06 14:40           ` Linus Torvalds
2010-03-26 17:42   ` David Howells
2010-03-26 17:45     ` Linus Torvalds [this message]
2010-03-26 17:58       ` Ralf Baechle
2010-03-26 18:03         ` Linus Torvalds
2010-03-26 18:16           ` Matthew Wilcox
2010-04-06 13:30           ` Matthew Wilcox
2010-04-14 11:49           ` David Howells
2010-04-14 14:30             ` Avi Kivity
2010-04-15  8:48             ` David Howells
2010-04-15  8:49               ` Avi Kivity
2010-04-15 11:41                 ` Jamie Lokier
2010-03-26 17:52     ` Matthew Wilcox
2010-04-14 13:13   ` David Howells

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