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In a multi-processor implementation, the processors may be arranged in
an implementation-dependent multi-dimensional processor array. The
system inquiry functions return values related to this underlying
machine and processor configuration, including the size and shape of
the underlying processor array. NUMBER_OF_PROCESSORS returns the
total number of processors available to the program or the number of
processors available to the program along a specified dimension of the
processor array. PROCESSORS_SHAPE returns the shape of the
processor array.
The values returned by the system inquiry intrinsic functions remain
constant for the duration of one program execution. Thus, NUMBER_OF_PROCESSORS and PROCESSORS_SHAPE have values that are
restricted expressions and may be used wherever any other Fortran 90
restricted expression may be used. In particular, NUMBER_OF_PROCESSORS may be used in a specification expression.
The values of system inquiry functions may not occur in initialization
expressions, because they may not be assumed to be constants. In
particular, HPF programs may be compiled to run on machines whose
configurations are not known at compile time.
Note that the system inquiry functions query the physical machine, and
have nothing to do with any PROCESSORS directive that may occur.
paula@erc.msstate.edu
Thu Dec 8 16:17:11 CST 1994