XL Fortran Enterprise Edition for AIX : User's Guide - IBM

-qddim Option
Syntax
-qddim | -qnoddim
DDIM | NODDIM
Specifies that the bounds of pointee arrays are re-evaluated each time the arrays
are referenced and removes some restrictions on the bounds expressions for
pointee arrays.
Rules
By default, a pointee array can only have dimension declarators containing
variable names if the array appears in a subprogram, and any variables in the
dimension declarators must be dummy arguments, members of a common block,
or use- or host-associated. The size of the dimension is evaluated on entry to the
subprogram and remains constant during execution of the subprogram.
With the -qddim option:
v The bounds of a pointee array are re-evaluated each time the pointee is
referenced. This process is called dynamic dimensioning. Because the variables in
the declarators are evaluated each time the array is referenced, changing the
values of the variables changes the size of the pointee array.
v The restriction on the variables that can appear in the array declarators is lifted,
so ordinary local variables can be used in these expressions.
v Pointee arrays in the main program can also have variables in their array
declarators.
Examples
@PROCESS DDIM
INTEGER PTE, N, ARRAY(10)
POINTER (P, PTE(N))
DO I=1, 10
ARRAY(I)=I
END DO
N = 5
P = LOC(ARRAY(2))
PRINT *, PTE ! Print elements 2 through 6.
N = 7 ! Increase the size.
PRINT *, PTE ! Print elements 2 through 8.
END
XL Fortran Compiler-Option Reference 147