The HLL interface is available directly for all programming languages that use the same conventions for transfer parameters to subprograms as COBOL and FORTRAN. For these programming languages, the function calls described on "Description of the function calls" apply.
The following conventions apply:
Register 1 must contain a pointer to the list of addresses of the transfer parameters.
The most significant bit in the last parameter address must be set (logically ORed with X’80000000’).
Register 13 contains the address of the register backup area (normally set by the program manager).
Calls that comply with the ILCS conventions are also supported. The following conventions apply:
Register 1 must contain a pointer to the list of parameter addresses.
Register 0 must contain the number of parameters.
Register 13 must contain the address of the register backup area (normally set by the program manager).
An interface satisfying these requirements was developed especially for C. This C interface is described in a separate section (see section “C interface”).
Under certain circumstances, the HLL interface can also be used by Assembler programs. The preconditions that apply are as follows:
The requisite parameter list must be available.
The address of the parameter list must be passed to SDF in register 1.
Register 13 must contain the address of a register backup area 18 words long which must be deleted before the call.
The entry name is ’SDF’.
The interface modules and the include elements are supplied in the library SYSLIB.SDF.<version>.