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Subject: Re: [PATCH 09/10] x86-32: use SSE for atomic64_read/set if available
From: Luca Barbieri <luca@luca-barbieri.com>
To: "H. Peter Anvin" <hpa@zytor.com>
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> This really sounds like the wrong optimization.  These functions aren't
> exactly all that complex in assembly (which would also allow them to be
> simple cli/do stuff/sti), and instead relying on gcc features which may
> or may not be well supported on x86 is inviting breakage down the line.
>
> That is particularly damaging, since the remaining 486-class users tend
> to be deeply embedded and thus we only find problems later.

There is the downside of adding a whole 386/486-specific implementation.

It's not too hard though, and if we don't care about 486 SMP, it may
be a better option.