Messages in this thread | | | Date | Thu, 18 Feb 2010 11:06:13 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH 09/10] x86-32: use SSE for atomic64_read/set if available |
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On 02/18/2010 10:49 AM, Luca Barbieri wrote: >> 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.
We don't care about 486 SMP. And yes, I think it is a better option. At least an assembly option, once implemented, will *stay* implemented and won't break due to some obscure gcc change.
-hpa
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