The IPCS automatic storage allocation macros require the saving of all registers.

• Traditional module linkage involves the saving of registers passed in a 72-byte save area via STM. Modules using this means to save registers should select macros from rows in Table 1 where the “Register saving” column says “STM”.
• A newer, hardware-assisted linkage convention employs the BAKR instruction to save registers. Modules using this means to save registers should select macros from rows where the “Register saving” column says “BAKR”.