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From: Scott Wood <scottwood@freescale.com>
To: Timur Tabi <timur@freescale.com>
Cc: Alexander Graf <agraf@suse.de>,
	Stuart Yoder <stuart.yoder@freescale.com>,
	kvm-ppc@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH v11 8/8] PPC: Don't use hardcoded opcode for ePAPR hcall invocation
Date: Mon, 02 Jul 2012 17:43:20 +0000	[thread overview]
Message-ID: <4FF1DDB8.6010504@freescale.com> (raw)
In-Reply-To: <4FF1DBB0.1080909@freescale.com>

On 07/02/2012 12:34 PM, Timur Tabi wrote:
> Scott Wood wrote:
> 
>> Hmm.  The comment says, "XER, CTR, and LR are currently listed as
>> clobbers because it's uncertain whether they will be clobbered."  Maybe
>> it dates back to when the ABI was still being discussed?  Timur, do you
>> recall?
> 
> Nope, sorry.  I'm sure we discussed this and looked at the code.  My guess
> is that we weren't certain what the compiler was going to do at the time.

I'm not sure how the compiler is involved here -- we're just telling it
what our asm code (and the asm code in the hypervisor) will do.

>  I'm still a little confused.  Which inline assembly code is clobbering LR?
>  Are you talking about the "BL" instruction, which wasn't there before?

Yes, I didn't realize that LR had been in the clobber list before that.

-Scott


  reply	other threads:[~2012-07-02 17:43 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-22 20:06 [PATCH v11 8/8] PPC: Don't use hardcoded opcode for ePAPR hcall invocation Stuart Yoder
2012-07-02 12:30 ` Alexander Graf
2012-07-02 17:10   ` Scott Wood
2012-07-02 17:13     ` Alexander Graf
2012-07-02 17:16       ` Scott Wood
2012-07-02 17:17         ` Alexander Graf
2012-07-02 17:25           ` Scott Wood
2012-07-02 17:34             ` Timur Tabi
2012-07-02 17:43               ` Scott Wood [this message]
2012-07-02 17:53                 ` Timur Tabi
2012-07-02 17:57                   ` Scott Wood
2012-07-02 18:02                     ` Timur Tabi
2012-07-03 15:22             ` Yoder Stuart-B08248

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