Rules for Loop Directives that Affect Array Assignment Statements

When certain loop directives precede an array assignment statement, they affect the implicit loops that are generated by the compiler.

The following loop directives can affect array assignment statements:

BLOCK_LOOP and NOBLOCK_LOOP

NOFUSION

CODE_ALIGN

NOUNROLL_AND_JAM

DISTRIBUTE POINT

NOVECTOR

FORCEINLINE

PREFETCH and NOPREFETCH

INLINE and NOINLINE

UNROLL and NOUNROLL

IVDEP

UNROLL_AND_JAM

LOOP COUNT

VECTOR

Usually only one of the general directives can precede the array assignment statement (one-dimensional-array = expression) to affect it. The BLOCK_LOOP and NOBLOCK_LOOP directives may precede array assignment statements with any rank variable on the left-hand-side of the assignment.

Other rules may apply to the general directives. For more information, see the description of each directive.

Examples

Consider the following:

             REAL A(10), B(10)
             ...
        !DIR$ IVDEP
             A = B + 3

This has the same effect as writing the following explicit loop:

       !DIR$ IVDEP
             DO I = 1, 10
                A (I) = B (I) + 3
             END DO

See Also