Messages in this thread | | | Date | Fri, 14 Mar 2008 08:51:11 +0100 | From | "H. Peter Anvin" <> | Subject | Re: [RFC] x86: bitops asm constraint fixes |
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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.
-hpa
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