Messages in this thread | | | From | Segher Boessenkool <> | Subject | Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures | Date | Thu, 16 Aug 2007 23:00:30 +0200 |
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> 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? GCC manual, section 6.1, "When is a Volatile Object Accessed?" doesn't say anything of the kind. PR33053 and some others.
> Honestly, given such confusion, and the propensity of the "volatile" > type-qualifier keyword to be ill-defined (or at least poorly > understood, > often inconsistently implemented), I'd (again) express my opinion that > it > would be best to avoid its usage, given other alternatives do exist.
Yeah. Or we can have an email thread like this every time someone proposes a patch that uses an atomic variable ;-)
Segher
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