m68k call frame support

[Roman Zippel]

Hi,

I'm trying to add support call frame exception handling, I added these
macros:

#define EH_RETURN_DATA_REGNO(N) ((N) < 2 ? (N) : INVALID_REGNUM)
#define EH_RETURN_STACKADJ_RTX  gen_rtx_REG (Pmode, 8)
#define EH_RETURN_HANDLER_RTX   gen_rtx_MEM (Pmode, plus_constant
(arg_pointer_rtx, 4))

But it doesn't work yet, with gdb I see it crashing in _Unwind_SetGR
coming from __gxx_personality_v0:

	_Unwind_SetGR (context, __builtin_eh_return_data_regno (0),
			(_Unwind_Ptr) &xh->unwindHeader);

When I check the context, I see that the registers d0/d1/a0/a1 aren't
initialised.  Where should this happen? What am I missing?

bye, Roman