ip2k.md

gcc-you can use this code to learn something about gcc, and inquire further into linux,

   #
   #
   #
   #
   #"
  "(ip2k_reorg_split_qimode
    && (GET_CODE (operands[1]) != CONST_INT
        || INTVAL (operands[1]) != 1))"
  [(set (reg:QI 10)
  	(match_dup 1))
   (set (match_dup 0)
   	(plus:HI (zero_extend:HI (reg:QI 10))
		 (match_dup 2)))])

(define_insn "*addhi3_immediate" ;			 0  1 2  3 4 5 6  7   8   9  a  b  c   d   e  f
  [(set (match_operand:HI 0 "nonimmediate_operand"     "=a,do,a,do,a,a,a,do,&uo,&uS,bf,bf,bf,&uS,&uo, u")
        (plus:HI (match_operand:HI 1 "general_operand" "%0, 0,0, 0,0,0,0, 0, rS, ro,uo,uo,uo, ro, rS,uo")
	         (match_operand 2 "immediate_operand"   "N, N,M, M,P,I,i, i,  N,  N, M, P, I,  i,  i, i")))]
  ""
  "@
   inc\\t%L0
   incsnz\\t%L0\;inc\\t%H0
   dec\\t%L0
   mov\\tw,#-1\;add\\t%L0,w\;addc\\t%H0,w
   mov\\tw,%2\;add\\t%L0,w
   mov\\tw,#%n2\;sub\\t%L0,w
   mov\\tw,%L2\;add\\t%L0,w\;mov\\tw,%H2\;add\\t%H0,w
   mov\\tw,%L2\;add\\t%L0,w\;mov\\tw,%H2\;addc\\t%H0,w
   mov\\tw,%H1\;mov\\t%H0,w\;incsnz\\tw,%L1\;inc\\t%H0\;mov\\t%L0,w
   mov\\tw,%H1\;mov\\t%H0,w\;incsnz\\tw,%L1\;inc\\t%H0\;mov\\t%L0,w
   mov\\tw,%H1\;push\\t%L1%<\;pop\\t%L0%>\;mov\\t%H0,w\;dec\\t%L0
   mov\\tw,%H1\;push\\t%L1%<\;pop\\t%L0%>\;mov\\t%H0,w\;mov\\tw,%2\;add\\t%L0,w
   mov\\tw,%H1\;push\\t%L1%<\;pop\\t%L0%>\;mov\\t%H0,w\;mov\\tw,#%n2\;sub\\t%L0,w
   mov\\tw,%L2\;add\\tw,%L1\;mov\\t%L0,w\;mov\\tw,%H2\;addc\\tw,%H1\;mov\\t%H0,w
   mov\\tw,%L2\;add\\tw,%L1\;mov\\t%L0,w\;mov\\tw,%H2\;addc\\tw,%H1\;mov\\t%H0,w
   mov\\tw,%L2\;add\\tw,%L1\;push\\twreg%<\;mov\\tw,%H2\;addc\\tw,%H1\;mov\\t%H0,w\;pop\\t%L0%>"
  [(set_attr "skip" "yes,no,yes,no,no,no,no,no,no,no,no,no,no,no,no,no")
   (set_attr "clobberw" "no,no,no,yes,yes,yes,yes,yes,yes,yes,yes,yes,yes,yes,yes,yes")])

(define_insn "*addhi3_nonimmediate" ;			      0  1  2    3 4   5   6  7
  [(set (match_operand:HI 0 "nonimmediate_operand"	  "=&bf,bf,&dS,&do,d,&rS,&rS, o")
	(plus:HI (match_operand:HI 1 "general_operand"      "%0, 0,  0,  0,0, ro, rS,rS")
		 (match_operand:HI 2 "nonimmediate_operand" "ro,uo, ro, rS,r, rS, ro,rS")))]
  ""
  "@
   mov\\tw,%L2\;add\\t%L0,w\;mov\\tw,%H2\;add\\t%H0,w
   mov\\tw,%L2\;push\\t%H2%<\;add\\t%L0,w\;pop\\twreg%>\;add\\t%H0,w
   mov\\tw,%L2\;add\\t%L0,w\;mov\\tw,%H2\;addc\\t%H0,w
   mov\\tw,%L2\;add\\t%L0,w\;mov\\tw,%H2\;addc\\t%H0,w
   mov\\tw,%L2\;push\\t%H2%<\;add\\t%L0,w\;pop\\twreg%>\;addc\\t%H0,w
   mov\\tw,%L2\;add\\tw,%L1\;mov\\t%L0,w\;mov\\tw,%H2\;addc\\tw,%H1\;mov\\t%H0,w
   mov\\tw,%L2\;add\\tw,%L1\;mov\\t%L0,w\;mov\\tw,%H2\;addc\\tw,%H1\;mov\\t%H0,w
   mov\\tw,%L2\;add\\tw,%L1\;mov\\t%L0,w\;mov\\tw,%H2\;addc\\tw,%H1\;mov\\t%H0,w")

(define_insn "*addhi3_nonimm_zero_extend_w"
  [(set (match_operand:HI 0 "nonimmediate_operand" "=a,ro,&ro,&rS,&rS, u")
	(plus:HI
	 (zero_extend:HI (reg:QI 10))
	 (match_operand:HI 1 "nonimmediate_operand" "0, 0, rS, rS, ro,uo")))]
  ""
  "@
   add\\t%L0,w
   add\\t%L0,w\;clr\\twreg\;addc\\t%H0,w
   add\\tw,%L1\;mov\\t%L0,w\;clr\\twreg\;addc\\tw,%H1\;mov\\t%H0,w
   add\\tw,%L1\;mov\\t%L0,w\;clr\\twreg\;addc\\tw,%H1\;mov\\t%H0,w
   add\\tw,%L1\;mov\\t%L0,w\;clr\\twreg\;addc\\tw,%H1\;mov\\t%H0,w
   add\\tw,%L1\;push\\twreg%<\;clr\\twreg\;addc\\tw,%H1\;mov\\t%H0,w\;pop\\t%L0%>"
  [(set_attr "skip" "yes,no,no,no,no,no")
   (set_attr "clobberw" "no,yes,yes,yes,yes,yes")])

(define_insn_and_split "*addhi3_nonimm_zero_extend"
  [(set (match_operand:HI 0 "nonimmediate_operand" "=a, ro,&ro,&rS,&rS, u")
	(plus:HI
	 (zero_extend:HI
	  (match_operand:QI 1 "general_operand"   "roR,roR, rS,roR, rS,rS"))
	 (match_operand:HI 2 "nonimmediate_operand" "0,  0, rS, rS, ro,uo")))]
  ""
  "#"
  "(ip2k_reorg_split_qimode)"
  [(set (reg:QI 10)
  	(match_dup 1))
   (set (match_dup 0)
   	(plus:HI (zero_extend:HI (reg:QI 10))
		 (match_dup 2)))])
  

;;
;; Add 32-bit integers.
;;

(define_expand "addsi3"
  [(set (match_operand:SI 0 "nonimmediate_operand" "")
	(plus:SI (match_operand:SI 1 "general_operand" "")
		 (match_operand:SI 2 "general_operand" "")))]
  ""
  "")

(define_insn "*push_addsi3"
  [(set (match_operand:SI 0 "push_operand"                  "=<,<,  <")
        (plus:SI (match_operand:SI 1 "nonimmediate_operand" "%g,g,  g")
		 (match_operand:SI 2 "general_operand"       "N,M,rSi")))]
  ""
  "*{
    switch (which_alternative) {
    case 0:
      OUT_AS1 (push, %D1%<);
      OUT_AS1 (push, %C1%<);
      OUT_AS1 (push, %B1%<);
      OUT_AS1 (push, %A1%>%>%>);
      OUT_AS1 (incsnz, 4(SP));
      OUT_AS1 (incsz, 3(SP));
      OUT_AS1 (page, 1f);
      OUT_AS1 (jmp, 1f);
      OUT_AS1 (incsnz, 2(SP));
      OUT_AS1 (inc, 1(SP));
      OUT_AS1 (1:,);
      return \"\";

    case 1:
      OUT_AS1 (push, %D1%<);
      OUT_AS1 (push, %C1%<);
      OUT_AS1 (push, %B1%<);
      OUT_AS1 (push, %A1%>%>%>);
      OUT_AS2 (mov, w, #-1);
      OUT_AS2 (add, 4(SP), w);
      OUT_AS2 (addc, 3(SP), w);
      OUT_AS2 (addc, 2(SP), w);
      OUT_AS2 (addc, 1(SP), w);
      return \"\";

    case 2:
      OUT_AS2 (mov, w, %D2);
      OUT_AS2 (add, w, %D1);
      OUT_AS1 (push, wreg%<);
      OUT_AS2 (mov, w, %C2);
      OUT_AS2 (addc, w, %C1);
      OUT_AS1 (push, wreg%<);
      OUT_AS2 (mov, w, %B2);
      OUT_AS2 (addc, w, %B1);
      OUT_AS1 (push, wreg%<);
      OUT_AS2 (mov, w, %A2);
      OUT_AS2 (addc, w, %A1);
      OUT_AS1 (push, wreg%>%>%>);
      return \"\";

    default:
      abort();
    }
  }"
  [(set_attr "clobberw" "no,yes,yes")])

(define_insn "*addsi3" ;				      0  1   2   3   4   5   6
  [(set
    (match_operand:SI 0 "nonimmediate_operand" "=ro,ro, ro, rS,&ro,&rS,&rS")
    (plus:SI
     (match_operand:SI 1 "nonimmediate_operand" "%0, 0,  0,  0, rS, ro, rS")
     (match_operand:SI 2 "general_operand"	 "N, M,rSi,roi,rSi,rSi,roi")))]
  ""
  "@
   incsnz\\t%D0\;incsz\\t%C0\;page\\t1f\;jmp\\t1f\;incsnz\\t%B0\;inc\\t%A0\;1:
   mov\\tw,#-1\;add\\t%D0,w\;addc\\t%C0,w\;addc\\t%B0,w\;addc\\t%A0,w
   mov\\tw,%D2\;add\\t%D0,w\;mov\\tw,%C2\;addc\\t%C0,w\;mov\\tw,%B2\;addc\\t%B0,w\;mov\\tw,%A2\;addc\\t%A0,w
   mov\\tw,%D2\;add\\t%D0,w\;mov\\tw,%C2\;addc\\t%C0,w\;mov\\tw,%B2\;addc\\t%B0,w\;mov\\tw,%A2\;addc\\t%A0,w
   mov\\tw,%D2\;add\\tw,%D1\;mov\\t%D0,w\;mov\\tw,%C2\;addc\\tw,%C1\;mov\\t%C0,w\;mov\\tw,%B2\;addc\\tw,%B1\;mov\\t%B0,w\;mov\\tw,%A2\;addc\\tw,%A1\;mov\\t%A0,w
   mov\\tw,%D2\;add\\tw,%D1\;mov\\t%D0,w\;mov\\tw,%C2\;addc\\tw,%C1\;mov\\t%C0,w\;mov\\tw,%B2\;addc\\tw,%B1\;mov\\t%B0,w\;mov\\tw,%A2\;addc\\tw,%A1\;mov\\t%A0,w
   mov\\tw,%D2\;add\\tw,%D1\;mov\\t%D0,w\;mov\\tw,%C2\;addc\\tw,%C1\;mov\\t%C0,w\;mov\\tw,%B2\;addc\\tw,%B1\;mov\\t%B0,w\;mov\\tw,%A2\;addc\\tw,%A1\;mov\\t%A0,w"
  [(set_attr "clobberw" "no,yes,yes,yes,yes,yes,yes")])

(define_insn "*push_addsi3_zero_extendqi" ;		      0   1
  [(set (match_operand:SI 0 "push_operand"                  "=<,  <")
        (plus:SI (zero_extend:SI
	           (match_operand:QI 1 "general_operand" "%roRi,rSi"))
	         (match_operand:SI 2 "general_operand"     "rSi,roi")))]
  ""
  "@
   mov\\tw,%D2\;add\\tw,%1\;push\\twreg%<\;mov\\tw,%C2\;addc\\tw,$ff\;push\\twreg%<\;mov\\tw,%B2\;addc\\tw,$ff\;push\\twreg%<\;mov\\tw,%A2\;addc\\tw,$ff\;push\\twreg%>%>%>
   mov\\tw,%D2\;add\\tw,%1\;push\\twreg%<\;mov\\tw,%C2\;addc\\tw,$ff\;push\\twreg%<\;mov\\tw,%B2\;addc\\tw,$ff\;push\\twreg%<\;mov\\tw,%A2\;addc\\tw,$ff\;push\\twreg%>%>%>")

(define_insn "*addsi3_zero_extendqi" ;
  [(set (match_operand:SI 0 "nonimmediate_operand"  "=ro, rS,&ro,&rS,&rS")
        (plus:SI
	 (zero_extend:SI
	  (match_operand:QI 1 "nonimmediate_operand" "rS,roR, rS,roR, rS"))
	 (match_operand:SI 2 "general_operand"        "0,  0,rSi,rSi,roi")))]
  ""
  "@
   mov\\tw,%1\;add\\t%D0,w\;clr\\twreg\;addc\\t%C0,w\;addc\\t%B0,w\;addc\\t%A0,w
   mov\\tw,%1\;add\\t%D0,w\;clr\\twreg\;addc\\t%C0,w\;addc\\t%B0,w\;addc\\t%A0,w
   mov\\tw,%1\;add\\tw,%D2\;mov\\t%D0,w\;mov\\tw,%C2\;addc\\tw,$ff\;mov\\t%C0,w\;mov\\tw,%B2\;addc\\tw,$ff\;mov\\t%B0,w\;mov\\tw,%A2\;addc\\tw,$ff\;mov\\t%A0,w
   mov\\tw,%1\;add\\tw,%D2\;mov\\t%D0,w\;mov\\tw,%C2\;addc\\tw,$ff\;mov\\t%C0,w\;mov\\tw,%B2\;addc\\tw,$ff\;mov\\t%B0,w\;mov\\tw,%A2\;addc\\tw,$ff\;mov\\t%A0,w
   mov\\tw,%1\;add\\tw,%D2\;mov\\t%D0,w\;mov\\tw,%C2\;addc\\tw,$ff\;mov\\t%C0,w\;mov\\tw,%B2\;addc\\tw,$ff\;mov\\t%B0,w\;mov\\tw,%A2\;addc\\tw,$ff\;mov\\t%A0,w")

(define_insn "*push_addsi3_zero_extendhi" ;		          0   1
  [(set (match_operand:SI 0 "push_operand"                      "=<,  <")
        (plus:SI (zero_extend:SI
	           (match_operand:HI 1 "nonimmediate_operand" "%roR,rSR"))
	         (match_operand:SI 2 "general_operand"         "rSi,roi")))]
  ""
  "@
   mov\\tw,%D2\;add\\tw,%L1\;push\\twreg%<\;mov\\tw,%C2\;addc\\tw,%H1\;push\\twreg%<\;mov\\tw,%B2\;addc\\tw,$ff\;push\\twreg%<\;mov\\tw,%A2\;addc\\tw,$ff\;push\\twreg%>%>%>
   mov\\tw,%D2\;add\\tw,%L1\;push\\twreg%<\;mov\\tw,%C2\;addc\\tw,%H1\;push\\twreg%<\;mov\\tw,%B2\;addc\\tw,$ff\;push\\twreg%<\;mov\\tw,%A2\;addc\\tw,$ff\;push\\twreg%>%>%>")

(define_insn "*addsi3_zero_extendhi" ;
  [(set (match_operand:SI 0 "nonimmediate_operand"  "=ro,rS,&ro,&rS,&rS")
        (plus:SI
	 (zero_extend:SI
	  (match_operand:HI 1 "nonimmediate_operand" "rS,ro, rS, ro, rS"))
	 (match_operand:SI 2 "general_operand"        "0, 0,rSi,rSi,roi")))]
  ""
  "@
   mov\\tw,%L1\;add\\t%D0,w\;mov\\tw,%H1\;addc\\t%C0,w\;clr\\twreg\;addc\\t%B0,w\;addc\\t%A0,w
   mov\\tw,%L1\;add\\t%D0,w\;mov\\tw,%H1\;addc\\t%C0,w\;clr\\twreg\;addc\\t%B0,w\;addc\\t%A0,w
   mov\\tw,%L1\;add\\tw,%D2\;mov\\t%D0,w\;mov\\tw,%C2\;addc\\tw,%H1\;mov\\t%C0,w\;mov\\tw,%B2\;addc\\tw,$ff\;mov\\t%B0,w\;mov\\tw,%A2\;addc\\tw,$ff\;mov\\t%A0,w
   mov\\tw,%L1\;add\\tw,%D2\;mov\\t%D0,w\;mov\\tw,%C2\;addc\\tw,%H1\;mov\\t%C0,w\;mov\\tw,%B2\;addc\\tw,$ff\;mov\\t%B0,w\;mov\\tw,%A2\;addc\\tw,$ff\;mov\\t%A0,w
   mov\\tw,%L1\;add\\tw,%D2\;mov\\t%D0,w\;mov\\tw,%C2\;addc\\tw,%H1\;mov\\t%C0,w\;mov\\tw,%B2\;addc\\tw,$ff\;mov\\t%B0,w\;mov\\tw,%A2\;addc\\tw,$ff\;mov\\t%A0,w")

;;
;; Add 64-bit integers.
;;

(define_expand "adddi3"
  [(set (match_operand:DI 0 "nonimmediate_operand" "")
	(plus:DI (match_operand:DI 1 "general_operand" "")
		 (match_operand:DI 2 "general_operand" "")))]
  ""
  "")

(define_insn "*push_adddi3"
  [(set (match_operand:DI 0 "push_operand"                  "=<,<,  <")
        (plus:DI (match_operand:DI 1 "nonimmediate_operand" "%g,g,  g")
		 (match_operand:DI 2 "general_operand"       "N,M,rSi")))]
  ""
  "*{
    switch (which_alternative)
      {
        case 0:
          OUT_AS1 (push, %Z1%<);
          OUT_AS1 (push, %Y1%<);
          OUT_AS1 (push, %X1%<);
          OUT_AS1 (push, %W1%<);
          OUT_AS1 (push, %V1%<);
          OUT_AS1 (push, %U1%<);
          OUT_AS1 (push, %T1%<);
          OUT_AS1 (push, %S1%>%>%>%>%>%>%>);
          OUT_AS1 (incsnz, 8(SP));
          OUT_AS1 (incsz, 7(SP));
          OUT_AS1 (page, 1f);
          OUT_AS1 (jmp, 1f);
          OUT_AS1 (incsnz, 6(SP));
          OUT_AS1 (incsz, 5(SP));
          OUT_AS1 (page, 1f);
          OUT_AS1 (jmp, 1f);
          OUT_AS1 (incsnz, 4(SP));
          OUT_AS1 (incsz, 3(SP));
          OUT_AS1 (page, 1f);
          OUT_AS1 (jmp, 1f);
          OUT_AS1 (incsnz, 2(SP));
          OUT_AS1 (inc, 1(SP));
          OUT_AS1 (1:,);
          return \"\";

        case 1:
          OUT_AS1 (push, %Z1%<);
          OUT_AS1 (push, %Y1%<);
          OUT_AS1 (push, %X1%<);
          OUT_AS1 (push, %W1%<);
          OUT_AS1 (push, %V1%<);
          OUT_AS1 (push, %U1%<);
          OUT_AS1 (push, %T1%<);
          OUT_AS1 (push, %S1%>%>%>%>%>%>%>);
          OUT_AS2 (mov, w, #-1);
          OUT_AS2 (add, 8(SP), w);
          OUT_AS2 (addc, 7(SP), w);
          OUT_AS2 (addc, 6(SP), w);
          OUT_AS2 (addc, 5(SP), w);
          OUT_AS2 (addc, 4(SP), w);
          OUT_AS2 (addc, 3(SP), w);
          OUT_AS2 (addc, 2(SP), w);
          OUT_AS2 (addc, 1(SP), w);
          return \"\";

        case 2:
          OUT_AS2 (mov, w, %Z2);
          OUT_AS2 (add, w, %Z1);
          OUT_AS1 (push, wreg%<);
          OUT_AS2 (mov, w, %Y2);
          OUT_AS2 (addc, w, %Y1);
          OUT_AS1 (push, wreg%<);
          OUT_AS2 (mov, w, %X2);
          OUT_AS2 (addc, w, %X1);
          OUT_AS1 (push, wreg%<);
          OUT_AS2 (mov, w, %W2);
          OUT_AS2 (addc, w, %W1);
          OUT_AS1 (push, wreg%<);
          OUT_AS2 (mov, w, %V2);
          OUT_AS2 (addc, w, %V1);
          OUT_AS1 (push, wreg%<);
          OUT_AS2 (mov, w, %U2);
          OUT_AS2 (addc, w, %U1);
          OUT_AS1 (push, wreg%<);
          OUT_AS2 (mov, w, %T2);
          OUT_AS2 (addc, w, %T1);
          OUT_AS1 (push, wreg%<);
          OUT_AS2 (mov, w, %S2);
          OUT_AS2 (addc, w, %S1);
          OUT_AS1 (push, wreg%>%>%>%>%>%>%>);
          return \"\";

        default:
          abort();
      }
  }"
  [(set_attr "clobberw" "no,yes,yes")])

(define_insn "*adddi3" ;			 0  1   2   3   4   5   6
  [(set
    (match_operand:DI 0 "nonimmediate_operand" "=ro,ro, ro, rS,&ro,&rS,&rS")
    (plus:DI
     (match_operand:DI 1 "nonimmediate_operand" "%0, 0,  0,  0, rS, ro, rS")
     (match_operand:DI 2 "general_operand"	 "N, M,rSi,roi,rSi,rSi,roi")))]
  ""
  "*{
    switch (which_alternative)
      {
        case 0:
          OUT_AS1 (incsnz, %Z0);
          OUT_AS1 (incsz, %Y0);
          OUT_AS1 (page, 1f);
          OUT_AS1 (jmp, 1f);
          OUT_AS1 (incsnz, %X0);
          OUT_AS1 (incsz, %W0);
          OUT_AS1 (page, 1f);
          OUT_AS1 (jmp, 1f);
          OUT_AS1 (incsnz, %V0);
          OUT_AS1 (incsz, %U0);
          OUT_AS1 (page, 1f);
          OUT_AS1 (jmp, 1f);
          OUT_AS1 (incsnz, %T0);
          OUT_AS1 (inc, %S0);
          OUT_AS1 (1:, );
          return \"\";

        case 1:
          OUT_AS2 (mov, w, #-1);
          OUT_AS2 (add, %Z0, w);
          OUT_AS2 (addc, %Y0, w);
          OUT_AS2 (addc, %X0, w);
          OUT_AS2 (addc, %W0, w);
          OUT_AS2 (addc, %V0, w);
          OUT_AS2 (addc, %U0, w);
          OUT_AS2 (addc, %T0, w);
          OUT_AS2 (addc, %S0, w);
          return \"\";

        case 2:
        case 3:
          OUT_AS2 (mov, w, %Z2);
          OUT_AS2 (add, %Z0, w);
          OUT_AS2 (mov, w, %Y2);
          OUT_AS2 (addc, %Y0, w);
          OUT_AS2 (mov, w, %X2);
          OUT_AS2 (addc, %X0, w);
          OUT_AS2 (mov, w, %W2);
          OUT_AS2 (addc, %W0, w);
          OUT_AS2 (mov, w, %V2);
          OUT_AS2 (addc, %V0, w);
          OUT_AS2 (mov, w, %U2);
          OUT_AS2 (addc, %U0, w);
          OUT_AS2 (mov, w, %T2);
          OUT_AS2 (addc, %T0, w);
          OUT_AS2 (mov, w, %S2);
          OUT_AS2 (addc, %S0, w);
          return \"\";

        case 4:
        case 5:
        case 6:
          OUT_AS2 (mov, w, %Z2);
          OUT_AS2 (add, w, %Z1);
          OUT_AS2 (mov, %Z0, w);
          OUT_AS2 (mov, w, %Y2);
          OUT_AS2 (addc, w, %Y1);
          OUT_AS2 (mov, %Y0, w);
          OUT_AS2 (mov, w, %X2);
          OUT_AS2 (addc, w, %X1);
          OUT_AS2 (mov, %X0, w);
          OUT_AS2 (mov, w, %W2);
          OUT_AS2 (addc, w, %W1);
          OUT_AS2 (mov, %W0, w);
          OUT_AS2 (mov, w, %V2);
          OUT_AS2 (addc, w, %V1);
          OUT_AS2 (mov, %V0, w);
          OUT_AS2 (mov, w, %U2);
          OUT_AS2 (addc, w, %U1);
          OUT_AS2 (mov, %U0, w);
          OUT_AS2 (mov, w, %T2);
          OUT_AS2 (addc, w, %T1);
          OUT_AS2 (mov, %T0, w);
          OUT_AS2 (mov, w, %S2);
          OUT_AS2 (addc, w, %S1);
          OUT_AS2 (mov, %S0, w);
          return \"\";

        default:
          abort();