(j3.2006) contiguous sections
Bill Long
longb
Mon Jul 7 17:26:30 EDT 2008
Consider this example:
Integer a(10)
Print *, is_contiguous(a(10:1:-1))
End
Does this print T or F? In 5.3.7, 6(c) we say "the elements of the
section in array element order [here a(10), a(9), ..., a(1)], are a
subset of the base object elements that are consecutive in array element
order [here a(1), a(2), ..., a(10)]." As a collection of elements,
these two sets are the same, so the condition of "subset" seems to be
satisfied. But did we intend that the ordering of the two sets also has
to to the the same? I think so, considering that we disallowed vector
subscripts. But it is not clear that the current wording clearly
supports that claim. Another way to ask the question is whether the
goal is "adjacent in memory", or "stride-1 access". From the
optimization point of view, the stride-1 access is the valuable objective.
Cheers,
Bill
--
Bill Long longb at cray.com
Fortran Technical Support & voice: 651-605-9024
Bioinformatics Software Development fax: 651-605-9142
Cray Inc., 1340 Mendota Heights Rd., Mendota Heights, MN, 55120
More information about the J3
mailing list