On Wed, Aug 19, 2015 at 02:53:47PM -0700, H.J. Lu wrote: > How about this > > @deftypefn {Built-in Function} {void *} __builtin_argument_pointer (void) > This function is similar to @code{__builtin_frame_address} with an > argument of 0, but it returns the address of the incoming arguments to > the current function rather than the address of its frame. Unlike > @code{__builtin_frame_address}, the frame pointer register isn't > required.
That last line isn't true, if your port uses INITIAL_FRAME_POINTER_RTX. Maybe it shouldn't be true otherwise either (but currently a hard frame pointer is forced, indeed). Have we gone full circle now? ;-) > The exact definition of this address depends upon the processor and the > calling convention. Usually some arguments are passed in registers and > the rest on the stack, and this builtin returns the address of the > first argument which would be passed on the stack. > @end deftypefn Segher