# 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 | NOVECTOR
CODE_ALIGN | PARALLEL and NOPARALLEL
DISTRIBUTE POINT | PREFETCH and NOPREFETCH
FORCEINLINE | SIMD
INLINE and NOINLINE | UNROLL and NOUNROLL
IVDEP | UNROLL_AND_JAM
LOOP COUNT | VECTOR
NOFUSION |
NOUNROLL_AND_JAM |

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

Parent topic: General Compiler Directives

## See Also

Rules for General Directives that Affect DO Loops