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Re: GCC interpretation of C11 atomics (DR 459)
- From: Florian Weimer <fweimer at redhat dot com>
- To: Janne Blomqvist <blomqvist dot janne at gmail dot com>
- Cc: nruslan_devel at yahoo dot com, gcc mailing list <gcc at gcc dot gnu dot org>
- Date: Tue, 27 Feb 2018 11:03:09 +0100
- Subject: Re: GCC interpretation of C11 atomics (DR 459)
- Authentication-results: sourceware.org; auth=none
- References: <1615980330.4453149.1519617655582.ref@mail.yahoo.com> <1615980330.4453149.1519617655582@mail.yahoo.com> <45a88b2b-2e64-58e7-f68b-a1a7511b6528@redhat.com> <CAO9iq9FA6GfQnEmQZRPk+PN7-2Y2kuoWX7+=GFoR5e2680ehKw@mail.gmail.com>
On 02/26/2018 07:36 PM, Janne Blomqvist wrote:
There is no such architectural guarantee. At least on some
micro-architecture (AMD Opteron "Istanbul") it's possible to construct
a test which fails, proving that at least on that micro-arch SSE2
load/store isn't guaranteed to be atomic.
Looks like I was wrong. Ugh.
Thanks,
Florian