SET_STACK_END    1083 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    1085 gc.c           #define SET_STACK_END SET_MACHINE_STACK_END(&th->machine_stack_end)