Messages in this thread | | | Date | Fri, 24 Dec 2010 22:11:06 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [cpuops cmpxchg double V1 1/4] Generic support for this_cpu_cmpxchg_double |
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On 12/24/2010 08:53 PM, Christoph Lameter wrote: > On Thu, 23 Dec 2010, H. Peter Anvin wrote: > >> There are two return registers; two machine registers can be returned in >> registers. [u]int128 is poorly implemented in a lot of gcc versions, >> since it really hasn't been exercised. However, two-word structures >> should work. I do not believe a two-word *array* works, though. > > Oh gosh. So we would be using a tight corner case for gcc that may only > work with certain versions of gcc? Note that the current version does only > return a boolean. There is no need for returning double words. I'd be > happy if we could *pass* double words. >
A structure is not a corner case; a uint128 would be.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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