or

Date:

02-09-2023

NAME

OR - Computes logical sum

SYNOPSIS

OR ([I=]i,[J=]j)

STANDARDS

Fortran extension

DESCRIPTION

OR is an elemental function. It accepts the following arguments:

i

Must be of type BOOLEAN, INTEGER, REAl, Cray pointer, or LOGICAL.

j

Must be of type BOOLEAN, INTEGER, REAl, Cray pointer, or LOGICAL.

NOTES

This is an outmoded routine. Refer to the Cray Fortran Reference Manual for information about outmoded features and their preferred standard alternatives.

The name of this intrinsic cannot be passed as an argument.

CAUTIONS

Unexpected results can occur when Boolean functions are declared external and then used with logical arguments. The external Boolean functions always treat their arguments as type Boolean and return a Boolean result.

RETURN VALUES

When given two arguments of type logical, OR computes a logical sum and returns a logical result.

When given two arguments of type INTEGER, REAL, BOOLEAN, or pointer, OR computes a bit-wise logical sum and returns a BOOLEAN result. No type conversion occurs.

The following tables show both the logical sum and bit-wise logical sum:

------------------------------------------------------
Logical        Logical       (Logical Variable 1) OR
Variable 1     Variable 2    (Logical Variable 2)
------------------------------------------------------
T              T             T
T              F             T
F              T             T
F              F             F
------------------------------------------------------

------------------------------------------------------
Bit of        Bit of        (Bit of Variable 1) OR
Variable 1    Variable 2    (Bit of Variable 2)
------------------------------------------------------
1             1             1
1             0             1
0             1             1
0             0             0
------------------------------------------------------

EXAMPLES

The following section of Fortran code shows the OR function used with two arguments of type logical:

LOGICAL L1, L2, L3
...
L3 = OR(L1,L2)

The following section of Fortran code shows the OR function used with two arguments of type integer. The bit patterns of the arguments and result are also shown. For clarity, only the rightmost 8 bits are shown.

INTEGER I1, I2, I3
I1 = 12
I2 = 10
...
I3 = OR(I1,I2)
    -------------------------------     -------------------------------
   | 0 |   |   |   |   |   |   |   |   | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 |
    -------------------------------    -------------------------------
                  I1                               I2
                  -------------------------------
                 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 0 |
                 -------------------------------
                                 I3