Syntax of Directives

HPF directives are consistent with Fortran syntax in the following sense: if any HPF directive were to be adopted as part of a future Fortran standard, the only change necessary to convert an HPF program would be to replace the directive-origin with blanks.

H201 hpf-directive-line	is directive-origin hpf-directive
H202 directive-origin	is !HPF$ or CHPF$ or *HPF$
H203 hpf-directive	is specification-directive or executable-directive
H204 directive-origin	is processors-directive or align-directive or distribute-directive or inherit-directive or template-directive or combined-directive or sequence-directive
H205 executable-directive	is independent-directive

Constraint:

An hpf-directive-line cannot be commentary following another statement on the same line.

Constraint:

A specification-direcive may appear only where a declaration-construct may appear.

Constraint:

An executable-directive may appear only where an executable-construct may appear.

Constraint:

An hpf-directive-line follows the rules of either Fortran free form (F95:3.3.1.1) or fixed form (F95:3.3.2.1) comment lines, depending on the source form of the surrounding Fortran source form in that program unit. (F95:3.3)

An hpf-directive is case insensitive and conforms to the rules for blanks in free source form (3.3.1), even in an HPF program otherwise in fixed source form. However an HPF-conforming language processor is not required to diagnose extra or missing blanks in an HPF directive. Note that, due to Fortran rules, the directive-origin in free source form must be the characters!HPF$. HPF directives may be continued, in which case each continued line also begins with a directive-origin. No statements may be interspersed within a continued HPF-directive. HPF directive lines must not apear within a continued statement. HPF directive lines may incluede trailing commentary.

The blanks in the adjacent keywords END FORALL and NO SEQUENCE are optional, in either source form.

An example of an HPF directive continuation in free source form is:

!HPF$ ALIGN ANTIDISESTABLISHMENTARIANISM (I,J,K) &
!HPF$        WITH ORNITHORHYNCHUS_ANATINUS (J,K,I)

An example of an HPF directive continuation in fixed source form follows. Observe that column 6 must be blank, except when signifying continuation.

!HPF$ ALIGN ANTIDISESTABLISHMENTARIANISM (I,J,K)
!HPF$*WITH ORNITHORHYNCHUS_ANATINUS (J,K,I)

his example shows an HPF directive continuation that is "universal" in that it can be treated as eithe fixed source form or free source form. Note that the "&" in the first line is in column 73. &

!HPF$ ALIGN ANTIDISESTABLISHMENTARIANISM (I,J,K)                        &
!HPF$&WITH ORNITHORHYNCHUS_ANATINUS (J,K,I)

Part iii introduces new directives, both specifications and executable ones, for the approved extensions to HPF 2.0. These are included below:

H206 specification-directive-extended	is processors-directive or subset-directive or align-directive or distribute-directive or inherit-directive or template-directive or combined-directive or sequence-directive or dynamic-directive or range-directive or shadow-directive
H208 executable-directive-extended	is independent-directive or realign-directive or redistribute-directive or on-directive or resident-directive

The following rule extends rule R215 of Fortran 95:

H208 executable-construct-extended

is action-stmt or case-construct or do-construct or if-construct or where-construct or on-construct or resident-construct or task-region-construct