HP UX Fortran Software Compiler directives

Table 42 Compatibility statements (continued)

Statement	Implementation	Description
MAP	DEC	Defines a union within a structure.
POINTER (Cray-style)	Cray	Declares Cray-style pointers and their objects.
RECORD	DEC	Declares a record of a previously defined
		structure
STATIC	Sun	Allocates storage in static memory.
STRUCTURE	DEC	Defines a named structure.
TYPE (I/O)	DEC	Writes to standard output.
UNION	DEC	Defines a union within a structure.
VIRTUAL	DEC	Declares an array.
VOLATILE	DEC	Allows data sharing between asynchronous
		processes.

Compiler directives

Compiler directives are coded lines in the source file that control the compiler’s state. Many vendors use a directive syntax that enables the compiler to treat the directive as a comment unless the compiler is specifically looking for that directive. For example, all directives recognized by HP Fortran begin with the character !in free format or C, *, or! in fixed format (in fixed format, the directive must also start in column 1).

A directive that uses the comment-like syntax will not cause the compilation to fail. However, if the compiler does not recognize the directive, then the functionality that the directive enables will be lost.

The directives listed in Table 11-2 are recognized by HP Fortran and are compatible with those available on other implementations. These directives are functionally compatible; that is, their effect on HP Fortran is compatible with that on the original implementation. See the HP Fortran Programmer’s Reference for detailed descriptions of the directives to check the level of compatibility. For usage information about these directives, see “Controlling vectorization locally” (page 104).

As noted in the table, some of the compatibility directives are effective only if the source file is compiled with either the +Oparallel or the +Ovectorize option; otherwise, the directive is treated as a comment and ignored. For information about using these options, see “Using the +Ovectorize option” (page 103).

Table 43 Compatibility directives

Vendor	Directive		Function	Option dependency
Cray	DIR$	IVDEP	Disables dependency checks.	+Oparallelor
				+Ovectorize
	DIR$	NO SIDE EFFECTS	Disables checks for side	+Oparallelor
			effects.	+Ovectorize
	DIR$	[NO]CONCUR	Enables [disables] code	+Oparallel
			generation for parallel
			execution.
	DIR$	[NO]VECTOR	Enables [disables]	+Ovectorize
			vectorization.
	FPP$	NODEPCHK	Disables dependency checks	+Oparallel or
				+Ovectorize

142 Porting to HP Fortran