SET_STACK_END    3881 gc.c           #define SET_STACK_END (SET_MACHINE_STACK_END(&th->machine.stack_end), th->machine.register_stack_end = rb_ia64_bsp())
SET_STACK_END    3883 gc.c           #define SET_STACK_END SET_MACHINE_STACK_END(&th->machine.stack_end)