Distributions and Processor Arrangements

 

In a DISTRIBUTE directive where every distributee is a dummy argument, either the dist-format-clause or the dist-target, or both, may begin with, or consist of, an asterisk.

• Without an asterisk, a dist-format-clause or dist-target is prescriptive; the clause describes a distribution and constitutes a request of the language processor to make it so. This might require (the implementation of) either the caller or the called subprogram to remap or copy the actual argument on entry at run time in order to satisfy the requested distribution for the dummy.
• Starting with an asterisk, a dist-format-clause or dist-target is descriptive. Such a directive is equivalent in every respect to a prescriptive directive, except that if the compiler cannot verify that no remapping of the actual is required, it may issue a diagnostic message to that effect. See Section 4.1 for further information on this point.
• Consisting of only an asterisk, a dist-format-clause or dist-target is transcriptive; the clause says nothing about the distribution but constitutes a request to the language processor to copy that aspect of the distribution from that of the actual argument. (The intent is that if the argument is passed by reference, no movement of the data will be necessary at run time.)

It is possible that, in a single DISTRIBUTE directive, the dist-format-clause might have an asterisk but not the dist-target, or vice versa.

 
• Examples
• What Happens When a Clause Is Omitted