Messages in this thread | | | Date | Fri, 17 Aug 2007 10:02:13 +0530 (IST) | From | Satyam Sharma <> | Subject | Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures |
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On Thu, 16 Aug 2007, Segher Boessenkool wrote:
> > Here, I should obviously admit that the semantics of *(volatile int *)& > > aren't any neater or well-defined in the _language standard_ at all. The > > standard does say (verbatim) "precisely what constitutes as access to > > object of volatile-qualified type is implementation-defined", but GCC > > does help us out here by doing the right thing. > > Where do you get that idea?
Try a testcase (experimentally verify).
> GCC manual, section 6.1, "When > is a Volatile Object Accessed?" doesn't say anything of the > kind.
True, "implementation-defined" as per the C standard _is_ supposed to mean "unspecified behaviour where each implementation documents how the choice is made". So ok, probably GCC isn't "documenting" this implementation-defined behaviour which it is supposed to, but can't really fault them much for this, probably. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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