Intel fortran-80 manual ~Return, Ca.~End, SUBROUTINE Statement, RETU RN Statement

Functions And Subroutines FORTRAN-SO

The subroutine is called by the CALL statement.

PROGRAM

CALL.. SUBROUTINE

.~RETURN

CA.~END

END

Subroutines, being external procedures, can be defined outside the program. By the time a program containing a CALL to the subroutine is executed, however, the subroutine must be part of the calling program, either by SUBROUTINE sub- program definition or by being linked to the program. External procedure linkage is described in the FORTRAN compiler operator's manual.

5.2.3 SUBROUTINE Statement

The SUBROUTINE statement is used only as the first statement of a SUBROUTINE subprogram. Its format is

SU BROUTI N E sub[([dum[,dum ]...])]

where

sub is the symbolic name of the subroutine.

dum is a dummy argument and is either a variable, array, or dummy procedure name.

If no dummy arguments are specified, either of the forms 'SUBROUTINE sub' or 'SUBROUTINE subO' is acceptable.

The symbolic name of the subroutine is a global name and must not be the same as any other name in the program unit.

The symbolic name of a dummy argument is local to the program unit and cannot be used in an EQUIVALENCE, SAVE, INTRINSIC, DATA, or COMMON state- ment, except as a common block name.

An example is shown following the RETURN statement.

5.2.4 RETU RN Statement

The RETURN statement returns control to the calling program unit. It may appear only in a FUNCTION or SUBROUTINE subprogram. These subprograms may have one or more RETURN statements, or they may have none at all. The END statement terminating such a program unit has the same effect as a RETURN.

The format of the RETURN statement is simply

RETURN

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