i = POPCNT( arg )
popcnt Integer. The number of one bits found in arg
arg Integer, Logical, or Real. The 64 bit input argument.
The external integer function POPCNT returns the count of ones found in arg. For equations and other information, see Volume 3: UNICOS Math and Scientific Library Reference Manual SR-2081 7.0, Cray Research, Inc.
Since POPCNT is not an ANSI Fortran 77 intrinsic function, it must be declared as an external function of type integer. For example: EXTERNAL POPCNT INTEGER POPCNT ... I = POPCNT( 'CCCCCCCCCCCCCCCC'X ) ! Same as I = 32