* explow.c (optimize_save_area_alloca): New function for targets

    * explow.c (optimize_save_area_alloca): New function for targets
        where SETJMP_VIA_SAVE_AREA is true.
        (allocate_dynamic_stack_space): On SETJMP_VIA_SAVE_AREA targets,
        compute the amount of stack space needed should we find later that
        setjmp is never called by this function, stuff rtl for this inside
        a REG_NOTE of the final SET of stack_pointer_rtx.
        * toplev.c (rest_of_compilation): If SETJMP_VIA_SAVE_AREA and
        current_function_calls_alloca, call optimize_save_area_alloca.
CVS ----------------------------------------------------------------------

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@17402 138bc75d-0d04-0410-961f-82ee72b054a4