5.4 Subrange Types
The r type descriptor defines a type as a subrange of another type. It is followed by type information for the type of which it is a subrange, a semicolon, an integral lower bound, a semicolon, an integral upper bound, and a semicolon. The AIX documentation does not specify the trailing semicolon, in an effort to specify array indexes more cleanly, but a subrange which is not an array index has always included a trailing semicolon (see Arrays).
Instead of an integer, either bound can be one of the following:
- The bound is passed by reference on the stack at offset offset
from the argument list. See Parameters, for more information on such
- The bound is passed by value on the stack at offset offset from
the argument list.
- The bound is passed by reference in register number
- The bound is passed by value in register number register-number.
- There is no bound.
Subranges are also used for builtin types; see Traditional Builtin Types.