HPF provides data mapping directives that are advisory in nature. The
mapping inquiry subroutines allow the program to determine the actual
mapping of an array at run time. It may be especially important to
know the exact mapping when an EXTRINSIC subprogram is invoked.
For these reasons, HPF includes mapping inquiry subroutines which
describe how an array is actually mapped onto a machine. To keep the
number of routines small, the inquiry procedures are structured as
subroutines with optional INTENT (OUT) arguments.