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Re: Discussion: What is unspec_volatile?

From: Paolo Bonzini <bonzini at gnu dot org>
To: "H.J. Lu" <hjl dot tools at gmail dot com>
Cc: Ian Lance Taylor <iant at google dot com>, Georg Johann Lay <avr at gjlay dot de>, gcc at gcc dot gnu dot org
Date: Sat, 13 Nov 2010 17:01:18 +0100
Subject: Re: Discussion: What is unspec_volatile?
References: <4CDCE2AD.5040007@gjlay.de> <mcrtyjnm3nb.fsf@google.com> <AANLkTinRiKxiLD9Y+TAmJea-Hpt8DiT6DjZ+UtHL5Tt4@mail.gmail.com> <4CDE6825.6000801@gnu.org> <AANLkTik3SSomiEHYZQCiZw9wpOsGd-ymRTtwm3UpO6+E@mail.gmail.com> <4CDEA726.3050602@gnu.org> <AANLkTi=F=7U2an7+CGQ2+-19MjHxbvxgPSHvT5QL2gU3@mail.gmail.com>

On 11/13/2010 04:28 PM, H.J. Lu wrote:

VZEROUPPER is no-nop to executions. But it isn't no-nop for performance.

IIUC it's a noop as GCC uses it. You could use it in 256-bit mode and it would be valid, but not a noop.

Paolo

Follow-Ups:
- Re: Discussion: What is unspec_volatile?
  - From: H.J. Lu

References:
- Discussion: What is unspec_volatile?
  - From: Georg Johann Lay
- Re: Discussion: What is unspec_volatile?
  - From: Ian Lance Taylor
- Re: Discussion: What is unspec_volatile?
  - From: H.J. Lu
- Re: Discussion: What is unspec_volatile?
  - From: Paolo Bonzini
- Re: Discussion: What is unspec_volatile?
  - From: H.J. Lu
- Re: Discussion: What is unspec_volatile?
  - From: Paolo Bonzini
- Re: Discussion: What is unspec_volatile?
  - From: H.J. Lu

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