[ HPF Home | Versions | Compilers | Projects | Publications | Applications | Benchmarks | Events | Contact ]

---

Next: Examples of Definitions Up: Storage Association Previous: Storage Association

Definitions

1. COMMON blocks are either sequential or nonsequential, as determined by either explicit directive or compiler default. A sequential COMMON block has a single common block storage sequence (5.5.2.1).
2. An aggregate variable group is a collection of variables whose individual storage sequences are parts of a single storage sequence.

   Variables associated by EQUIVALENCE statements or by a combination of EQUIVALENCE and COMMON statements form an aggregate variable group. The variables of a sequential COMMON block form a single aggregate variable group.

3. The size of an aggregate variable group is the number of storage units in the group's storage sequence (14.6.3.1).

4. If there is a member in an aggregate variable group whose storage sequence is totally associated (14.6.3.3) with the storage sequence of the aggregate variable group, that variable is called an aggregate cover.

5. Variables are either sequential or nonsequential. A variable is sequential if and only if any of the following holds:
   1. it appears in a sequential COMMON block;

   2. it is a member of an aggregate variable group;

   3. it is an assumed-size array;

   4. it is a component of a derived type with the Fortran 90 SEQUENCE attribute; or

   5. it is declared to be sequential in an HPF SEQUENCE directive.

   A sequential variable can be storage associated or sequence associated; nonsequential variables cannot.

6. A COMMON block contains a sequence of components. Each component is either an aggregate variable group, or a variable that is not a member of any aggregate variable group. Sequential COMMON blocks contain a single component. Nonsequential COMMON blocks may contain several components that may be nonsequential or sequential variables or aggregate variable groups.

7. A variable is explicitly mapped if it appears in an HPF alignment or distribution directive within the scoping unit in which it is declared; otherwise it is implicitly mapped.

Next: