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SubjectRe: [RFC] x86: bitops asm constraint fixes
>>> "H. Peter Anvin" <> 14.03.08 08:51 >>>
>Jan Beulich wrote:
>> I'd really like understand, though, what the policy of (not) having a
>> "memory" clobber in these operations is - currently, this appears to
>> be totally inconsistent. Also, many comments of the non-atomic
>> functions say those may also be re-ordered - this contradicts the use
>> of "asm volatile" in there, which again I'd like to understand.
>In general, proper "m" constraints are better than "memory" clobbers,
>since they give gcc more information. Note that the "m" constraint
>doesn't actually have to be *manifest* in the assembly string.

... which is the case with the patch applied.

So am I taking this as 'yes, a proper re-write of these routines is
worthwhile'? But - you didn't comment on the other issues raised,
so before getting to that I'll have to wait to see what's the reason
(if any) for the other anomalies.


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