Re: [PATCH 09/10] x86-32: use SSE for atomic64_read/set if available

[H. Peter Anvin]

On 02/18/2010 02:27 AM, Luca Barbieri wrote:
>> So why don't you simply use normal asm inputs/outputs?
> I do, on the caller side.
> 
> In the callee, I don't see any other robust way to implement parameter
> passing in ebx/esi other than global register variables (without
> resorting to pure assembly, which would prevent reusing the generic
> atomic64 implementation).

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.

	-hpa
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