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Date: Fri, 29 Oct 2004 12:12:07 -0700 (PDT)
From: Linus Torvalds <torvalds@osdl.org>
To: linux-os@analogic.com
cc: Andreas Steinmetz <ast@domdv.de>,
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       Richard Henderson <rth@redhat.com>, Andi Kleen <ak@muc.de>,
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Subject: Re: Semaphore assembly-code bug
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On Fri, 29 Oct 2004, linux-os wrote:
> 
> Linus, there is no way in hell that you are going to move
> a value from memory into a register (pop ecx) faster than
> you are going to do anything to the stack-pointer or
> any other register.

Sorry, but you're wrong.

Learn about modern CPU's some day, and realize that cached accesses are 
fast, and pipeline stalls are relatively much more expensive.

Now, if it was uncached, you'd have a point.

Also think about why

	call xxx
	jmp yy

is often much faster than

	push $yy
	jmp xxx

and other small interesting facts about how CPU's actually work these 
days.

		Linus