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From: "fw at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/80878] -mcx16 (enable 128 bit CAS) on x86_64 seems not
 to work on 7.1.0
Date: Thu, 03 Nov 2022 10:32:09 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D80878

--- Comment #39 from Florian Weimer <fw at gcc dot gnu.org> ---
(In reply to Jakub Jelinek from comment #38)
> Please see PR104688 .  We got a response from Intel, where they guaranteed
> atomicity of certain 16-byte load instructions for Intel CPUs with AVX
> support.
> AFAIK we didn't get similar guarantee from AMD.

I'm trying to work with AMD to get an official statement that covers older =
CPUs
as well. I have a preliminary statement, but I hope to get to the point tha=
t we
can say the rule is the same as for Intel (AVX support can act as a proxy).=