Alternate Returns (SUBROUTINE and RETURN)

Subroutines with alternate returns (e.g. SUBROUTINE X(*) and CALL X(*50)) are implemented by g77 as functions returning the C int type. The actual alternate-return arguments are omitted from the calling sequence. Instead, the caller uses the return value to do a rough equivalent of the Fortran computed-GOTO statement, as in GOTO (50), X() in the example above (where X is quietly declared as an INTEGER(KIND=1) function), and the callee just returns whatever integer is specified in the RETURN statement for the subroutine For example, RETURN 1 is implemented as X = 1 followed by RETURN in C, and RETURN by itself is X = 0 and RETURN).