[MPI3 Fortran] Fortran extra_state argument to MPI attributefunctions
Bill Long
longb at cray.com
Thu May 28 09:20:48 CDT 2009
N.M. Maclaren wrote:
> On May 28 2009, Bill Long wrote:
>>
>> If you know about so-called "Cray pointers" (more accurately,
>> Livermore pointers from LRLtran), C_PTR is just a typealias for a
>> typeless Cray pointer (pointer(*,*)). In fact, that's exactly how
>> it's defined in our iso_c_binding module. Similarly, C_LOC has the
>> same effect as the Cray (and other vendors) LOC function. The
>> intent of C_PTR and C_LOC was to give these common extensions
>> standardized, and hence portable, names and syntax.
>
> Yes and no. There are a heck of a lot of restrictions to C_PTR and C_LOC
> that are intended to exclude the most problematic aspects of Cray
> pointers,
Yes, I skimmed over that detail. The compiler need to enforce the
semantic restrictions associated with C_PTR and C_LOC. These are
restrictions on the user. Inside the compiler, the mechanical
implementation is the same as for Cray pointers.
--
Bill Long longb at cray.com
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Cray Inc., 1340 Mendota Heights Rd., Mendota Heights, MN, 55120
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