User guide

To comply with the ATPCS in assembly language, unless your object file contains no external calls, you must:

• Ensure that 8-byte alignment of the stack is preserved at all external interfaces. (The stack pointer must always

move by an even number of words between entry to your code and any external call from your code.)

• Use the PRESERVE8 directive to inform the linker that 8-byte alignment is preserved (see the Directives

Reference chapter in Assembler Guide

Using the Procedure Call Standard