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Subject: [Bug target/103069] cmpxchg isn't optimized
Date: Wed, 23 Feb 2022 03:35:04 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103069

--- Comment #19 from Hongyu Wang <wwwhhhyyy333 at gmail dot com> ---
(In reply to Thiago Macieira from comment #18)
> (In reply to Jakub Jelinek from comment #17)
> > _Pragma("GCC target \"relax-cmpxchg-loop\"")
> > should do that (ditto target("relax-cmpxchg-loop") attribute).
>=20
> The attribute is applied to a function. I'm hoping to do it for s block of
> code:
>=20
>  _Pragma("GCC push_options")
>  _Pragma("GCC target \"relax-cmpxchg-loop\"")
>  __atomic_compare_exchange_weak(....);
>  _Pragma("GCC pop_options")

I'm not aware of any target __attribute__ or #Pragma can be used to code bl=
ock,
at this level user can change their code directly, so I don't know why it is
needed..=