Committed, MMIX: Fix nonlocal_goto_receiver, a whole lot of EH testfailures.

[Hans-Peter Nilsson <hp at bitrange dot com>]

Fixing most of those pesky remaining C++ FAILs in one blow, i.e.
execution tests for g++.dg/eh/registers1.C, g++.old-deja
g++.abi/cxa_vec.C, g++.eh/spec2.C, g++.eh/spec3.C,
g++.mike/eh33.C, g++.mike/eh50.C and g++.mike/eh51.C.  The FIXME
at that insn was on spot; gcc re-used a register holding the
address of that stack-slot from one EH handler to another
handler for a subequent catch.  All stack-slot address variants
are emitted in the libstdc++ code, no need for separate tests.
Will commit this to 3.1 too.

	* config/mmix/mmix.md (define_constants): Remove misleading
	FIXME.  Add MMIX_fp_rO_OFFSET.
	("nonlocal_goto_receiver"): Don't have stack-frame address of
	saved rO as part of the pattern.  Remove FIXME.
	("*nonlocal_goto_receiver_expanded"): Similar.  Generate address
	here, at output-time.

Index: mmix.md
===================================================================
RCS file: /cvs/gcc/gcc/gcc/config/mmix/mmix.md,v
retrieving revision 1.10
diff -p -c -r1.10 mmix.md
*** mmix.md	2002/03/18 01:20:14	1.10
--- mmix.md	2002/03/31 16:34:03
***************
*** 34,44 ****
  ;; The order of insns is as in Node: Standard Names, with smaller modes
  ;; before bigger modes.

- ;; FIXME:s
- ;; - Use new formats; e.g. '{' not '"*{'.
-
  (define_constants
!   [(MMIX_rJ_REGNUM 259)]
  )

  ;; FIXME: Can we remove the reg-to-reg for smaller modes?  Shouldn't they
--- 34,42 ----
  ;; The order of insns is as in Node: Standard Names, with smaller modes
  ;; before bigger modes.

  (define_constants
!   [(MMIX_rJ_REGNUM 259)
!    (MMIX_fp_rO_OFFSET -24)]
  )

  ;; FIXME: Can we remove the reg-to-reg for smaller modes?  Shouldn't they
*************** DIVU %1,%1,%2\;GET %0,:rR\;NEGU %2,0,%0\
*** 1101,1135 ****
  ;; of "pop 0,0" until rO equals the saved value.  (If it goes lower, we
  ;; should call abort.)
  (define_expand "nonlocal_goto_receiver"
!   [(parallel [(unspec_volatile [(match_dup 0)] 1)
  	      (clobber (scratch:DI))
  	      (clobber (reg:DI MMIX_rJ_REGNUM))])
!    (set (reg:DI MMIX_rJ_REGNUM) (match_dup 1))]
    ""
    "
  {
!   rtx tem
!     = validize_mem (gen_rtx_MEM (Pmode,
! 				 plus_constant (frame_pointer_rtx, -24)));
!   operands[0] = XEXP (tem, 0);
!   operands[1]
      = get_hard_reg_initial_val (Pmode, MMIX_INCOMING_RETURN_ADDRESS_REGNUM);

    /* Mark this function as containing a landing-pad.  */
    cfun->machine->has_landing_pad = 1;
  }")

! ;; FIXME: Do we need to keep this in memory?  Can GCC counter our
! ;; expectations and use saved registers to keep the slot address in,
! ;; "across" the exception or goto?  Anyway, we need to make sure the value
! ;; ends up in a non-local register, so best is to load it ourselves.
  (define_insn "*nonlocal_goto_receiver_expanded"
!   [(unspec_volatile [(match_operand:DI 0 "address_operand" "p")] 1)
!    (clobber (match_scratch:DI 1 "=&r"))
     (clobber (reg:DI MMIX_rJ_REGNUM))]
    ""
!   "GETA $255,0f\;PUT rJ,$255\;LDOU $255,%a0\n\
! 0:\;GET %1,rO\;CMPU %1,%1,$255\;BNP %1,1f\;POP 0,0\n1:")

  (define_insn "*Naddu"
    [(set (match_operand:DI 0 "register_operand" "=r")
--- 1099,1168 ----
  ;; of "pop 0,0" until rO equals the saved value.  (If it goes lower, we
  ;; should call abort.)
  (define_expand "nonlocal_goto_receiver"
!   [(parallel [(unspec_volatile [(const_int 0)] 1)
  	      (clobber (scratch:DI))
  	      (clobber (reg:DI MMIX_rJ_REGNUM))])
!    (set (reg:DI MMIX_rJ_REGNUM) (match_dup 0))]
    ""
    "
  {
!   operands[0]
      = get_hard_reg_initial_val (Pmode, MMIX_INCOMING_RETURN_ADDRESS_REGNUM);

    /* Mark this function as containing a landing-pad.  */
    cfun->machine->has_landing_pad = 1;
  }")

! ;; GCC can insist on using saved registers to keep the slot address in
! ;; "across" the exception, or (perhaps) to use saved registers in the
! ;; address and re-use them after the register stack unwind, so it's best
! ;; to form the address ourselves.
  (define_insn "*nonlocal_goto_receiver_expanded"
!   [(unspec_volatile [(const_int 0)] 1)
!    (clobber (match_scratch:DI 0 "=&r"))
     (clobber (reg:DI MMIX_rJ_REGNUM))]
    ""
! {
!   rtx temp_reg = operands[0];
!   rtx my_operands[2];
!   HOST_WIDEST_INT offs;
!   const char *my_template
!     = "GETA $255,0f\;PUT rJ,$255\;LDOU $255,%a0\n\
! 0:\;GET %1,rO\;CMPU %1,%1,$255\;BNP %1,1f\;POP 0,0\n1:";
!
!   my_operands[1] = temp_reg;
!
!   /* If we have a frame-pointer (hence unknown stack-pointer offset),
!      just use the frame-pointer and the known offset.  */
!   if (frame_pointer_needed)
!     {
!       my_operands[0] = GEN_INT (-MMIX_fp_rO_OFFSET);
!
!       output_asm_insn ("NEGU %1,0,%0", my_operands);
!       my_operands[0] = gen_rtx_PLUS (Pmode, frame_pointer_rtx, temp_reg);
!     }
!   else
!     {
!       /* We know the fp-based offset, so "eliminate" it to be sp-based.  */
!       offs
! 	= (mmix_initial_elimination_offset (MMIX_FRAME_POINTER_REGNUM,
! 					    MMIX_STACK_POINTER_REGNUM)
! 	   + MMIX_fp_rO_OFFSET);
!
!       if (offs >= 0 && offs <= 255)
! 	my_operands[0]
! 	  = gen_rtx_PLUS (Pmode, stack_pointer_rtx, GEN_INT (offs));
!       else
! 	{
! 	  mmix_output_register_setting (asm_out_file, REGNO (temp_reg),
! 					offs, 1);
! 	  my_operands[0] = gen_rtx_PLUS (Pmode, stack_pointer_rtx, temp_reg);
! 	}
!     }
!
!   output_asm_insn (my_template, my_operands);
!   return "";
! })

  (define_insn "*Naddu"
    [(set (match_operand:DI 0 "register_operand" "=r")

brgds, H-P