Use Subroutine Linkage Conventions in Interlanguage Calls

The subroutine linkage conventions describes the machine state at subroutine entry and exit. Routines that are compiled separately in the same or different languages are linked when the programs are linked, and run when called. The AIX Version 4 Assembler Language Reference describes the Subroutine Linkage Convention in detail.

The RISC System/6000 linkage convention provides fast and efficient subroutine linkage between languages. It specifies how parameters are passed, taking full advantage of the large number of floating-point registers (FPRs) and general-purpose registers (GPRs), and minimizes the saving and restoring of registers on subroutine entry and exit.

• Parameter Passing
• Call-by-Reference Parameters
• Call-by-Value Parameters
• Rules for Passing Parameters by Value
• Pointers to Functions
• Function Return Values
• Stack Floor
• Stack Overflow
• Traceback Table
• Type Encoding and Checking

Interlanguage Calling Conventions
Corresponding Data Types
Sample Program: C Calling Fortran