/INTEGER_SIZE

  Controls how the compiler interprets INTEGER or LOGICAL
  declarations that do not have a specified length.  The default is
  /INTEGER_SIZE=32.

  You can specify the following values:

  /INTEGER=16    INTEGER declarations are interpreted
                 as INTEGER(KIND=2) and LOGICAL declarations
                 as LOGICAL(KIND=2).  This is the same as
                 the obsolete /NOI4 qualifier.

  /INTEGER=32    INTEGER declarations are interpreted
                 as INTEGER(KIND=4) and LOGICAL declarations
                 as LOGICAL(KIND=4).  This is the same as
                 the obsolete /I4 qualifier.

  /INTEGER=64    INTEGER declarations are interpreted
                 as INTEGER(KIND=8) and LOGICAL declarations
                 as LOGICAL(KIND=8).

  You must explicitly declare INTEGER(KIND=1) data.

                                 NOTE

          To improve performance, use /INTEGER_SIZE=32 rather
          than  /INTEGER_SIZE=16  and  declare  variables  as
          INTEGER(KIND=4) (or  INTEGER(KIND=8))  rather  than
          INTEGER(KIND=2)  or  INTEGER(KIND=1).   For logical
          data,  avoid  using  /INTEGER_SIZE=16  and  declare
          logical  variables  as  LOGICAL(KIND=4) rather than
          LOGICAL(KIND=2) or LOGICAL(KIND=1).