Fortran Directives Summary

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This appendix summarizes the directives recognized by f95 Fortran compiler:

General Fortran Directives
Sun Parallelization Directives
Cray Parallelization Directives
OpenMP Fortran 95 Directives, Library Routines, and Environment

C.1 General Fortran Directives

General directives accepted by f95 are described in Directives.

Table C-1 Summary of General Fortran Directives

Format
`!$PRAGMA` `keyword` `(` a `[ ,` a `]` `… )` [ , `keyword` ( a [ , a `]` `… )` `]` `,…` `!$PRAGMA SUN` `keyword` `(` a `[ ,` a `]` `… )` [ , `keyword` ( a [ , a `]` `… )` `]` `,…` Comment-indicator in column 1 may be `c`, `C`, `!`, or `*.` (We use `!` in these examples. `f95` free-format must use `!`.)
`C` Directive	`!$PRAGMA C(list)` Declares a list of names of external functions as C language routines.
`IGNORE_TKR` `Directive`	`!$PRAGMA IGNORE_TKR` {`name` {, `name`} ...} The compiler ignores the type, kind, and rank of the specified dummy argument names appearing in a generic procedure interface when resolving a specific call.
`UNROLL` Directive	`!$PRAGMA SUN UNROLL=n` Advises the compiler that the following loop can be unrolled to a length `n`.
`WEAK` Directive	`!$PRAGMA WEAK(name`[`=name2`]`)` Declares `name` to be a weak symbol, or an alias for `name2`.
`OPT` Directive	`!$PRAGMA SUN OPT=n` Set optimization level for a subprogram to `n`.
`PIPELOOP` Directive	`!$PRAGMA SUN PIPELOOP`[`=n`] Assert dependency in loop between iterations `n` apart.
`PREFETCH` Directives	`!$PRAGMA SUN_PREFETCH_READ_ONCE (name)` `!$PRAGMA SUN_PREFETCH_READ_MANY (name)` `!$PRAGMA SUN_PREFETCH_WRITE_ONCE (name)` `!$PRAGMA SUN_PREFETCH_WRITE_MANY (name)` Request compiler generate prefetch instructions for references to name. (Requires `-xprefetch` option, which is enabled by default. Prefetch directives can be disabled by compiling with `—xprefetch=no`. Target architecture must also support prefetch instructions, and the compiler optimization level must be set greater than `—xO2`.)
`ASSUME` `Directives`	`!$PRAGMA` [`BEGIN`} `ASSUME` `(expression` [`,probability`]`)` `!$PRAGMA END ASSUME` Make assertions about conditions at certain points in the program that the compiler can assume are true.

C.2 Special Fortran Directives

The following directives are only available with f95. See FIXED and FREE Directives for details.

Table C-2 Special Fortran Directives

Format	`!DIR$` `directive` : initial line `!DIR$&` ... : continuation line With fixed-format source, `C` is also accepted as a directive-indicator: `CDIR$` `directive`... The line must start in column 1. With free-format source, the line may be preceded by blanks.
`FIXED/FREE` Directives	`!DIR$ FREE!DIR$ FIXED` These directives specify the source format of the lines following the directive. They apply to the rest of the source file in which they appear, up to the next `FREE` or `FIXED` directive.
`IVDEP`	`!DIR$ IVDEP` Assert that the following `DO`, `FORALL`, or `WHERE` loop is free of loop-carried dependences, and can be optimized. Interpretation determined by the `-xivdep` option. See IVDEP Directive

C.3 Fortran OpenMP Directives

The Oracle Solaris Studio Fortran compiler supports the OpenMP 3.1 Fortran API. The -openmp compiler flag enables these directives. (See –xopenmp[={parallel|noopt|none}]).

See the OpenMP API User’s Guide for complete details.