# Rules for General Directives that Affect DO Loops

This table lists the general directives that affect DO loops:

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

The following rules apply to all of the general directives:

- The directive must precede the DO statement for each DO loop it affects. The DO statement can be any of the following:

  - A counted DO loop

  - A DO WHILE loop

  - A DO CONCURRENT loop

- No source code lines, other than the following, can be placed between the directive statement and the DO statement:

  - One of the other general directives that affect DO loops

  - An OpenMP* Fortran PARALLEL DO directive

  - Comment lines

  - Blank lines

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

Parent topic: General Compiler Directives

## See Also

Rules for Loop Directives that Affect Array Assignment Statements