UNROLL

General Compiler Directive: Tells the compiler's optimizer how many times to unroll a DO loop. It can only be applied to iterative DO loops.

Syntax

cDEC$ UNROLL [(n)]

c
Is one of the following: C (or c), !, or *. (See Syntax Rules for General Directives.)

n
Is an integer constant. The range of n is 0 through 255.

Rules and Behavior

The UNROLL directive must precede the DO statement for each DO loop it affects. No source code lines, other than the following, can be placed between the UNROLL directive statement and the DO statement:

• An IVDEP directive
• A PARALLEL DO directive (TU*X only)
• A PDO directive (TU*X only)
• Placeholder lines
• Comment lines
• Blank lines

If n is specified, the optimizer unrolls the loop n times. If n is omitted, or if it is outside the allowed range, the optimizer picks the number of times to unroll the loop.

The UNROLL directive overrides any setting of loop unrolling from the command line.

Compatibility

CONSOLE STANDARD GRAPHICS QUICKWIN GRAPHICS WINDOWS DLL LIB

See Also: General Compiler Directives