Intel® Fortran Compiler 17.0 Developer Guide and Reference
A DO construct has an extended range if both of the following are true:
The DO construct contains a control statement that transfers control out of the construct.
Another control statement returns control back into the construct after execution of one or more statements.
The range of the construct is extended to include all executable statements between the destination statement of the first transfer and the statement that returns control to the construct.
The following rules apply to a DO construct with extended range:
A transfer into the range of a DO statement is permitted only if the transfer is made from the extended range of that DO statement.
The extended range of a DO statement must not change the control variable of the DO statement.
The following figure shows valid and invalid extended range control transfers: