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Date: Thu, 18 Feb 2010 23:57:11 +0100
From: Pavel Machek <pavel@ucw.cz>
To: "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: register long sp asm("r1") incorrect
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On Mon 2010-02-15 14:15:17, H. Peter Anvin wrote:
> On 02/15/2010 01:04 PM, Benjamin Herrenschmidt wrote:
> > 
> > It's true that most other use of it we have are global scope (local_paca
> > in r13, glibc use of r2/r13, etc...) afaik, but since r1 itself is the
> > stack pointer always, I think they pretty much guarantee it works.
> > 
> 
> It should work, because r1, being the stack pointer, is already marked a
> reserved register in gcc.
> 
> The reference Pavel is citing bascially states that gcc won't globally
> reserve the register, which is true, but it is already reserved anyway.

Ok, thanks for clarification.

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