SUBROUTINE  GEN (OPIN, LEFTIN, RIN) 
      INTEGER     OPIN, LEFTIN, RIN 
 
      INTEGER     OP, LEFT, RIGHT, LSTKX, RSTKX 
      INTEGER     TS, LOAD, BASE 
      INTEGER     THIS, OTHER, SIDE, HI, LOW 
      INTEGER     INTBR, ROW, COL, INREG, OUTREG 
      INTEGER     BCC, BNE 
      INTEGER     CLC, JMP, LDAABS, LDAI, LDAZP 
      INTEGER     SBCI, SEC, STAZP, TAX, TXA 
      LOGICAL     COMZER, EZSTA, MORE 
      COMMON      /GCOM/   OP, LEFT, RIGHT, LSTKX, RSTKX 
      COMMON      /GCOM/   TS, LOAD, BASE 
      COMMON      /GCOM/   THIS, OTHER, SIDE, HI, LOW 
      COMMON      /GCOM/   INTBR, ROW, COL, INREG, OUTREG 
      COMMON      /GCOM/   BCC, BNE 
      COMMON      /GCOM/   CLC, JMP, LDAABS, LDAI, LDAZP 
      COMMON      /GCOM/   SBCI, SEC, STAZP, TAX, TXA 
      COMMON      /GCOM/   COMZER, EZSTA, MORE 
 
      INTEGER     ADDR,   ADRFLG, CUROP,  NEXTOP, CFLAG 
      INTEGER     PI,     XBBL,   XA,     XF,     XZERO,  DPVFLG 
      INTEGER     LC,     LCI,    LODLCI, LODLCV, LDLCVO, MAXLCV 
      INTEGER     NEXT,   NUMBER, I,      IOTYPE 
      INTEGER     J,      K,      L,      LABNLX, M,      N 
      INTEGER     PSYMB,  SYMBOL, TOP,    VALFLG, QVALUE 
      INTEGER     OPTOPX, OPNXTX, TOPX,   NEXTX 
      INTEGER     DUMMY,  OVCHN,  PEEKS 
      INTEGER     LO,     CI,     CO,     LOGICF, LOCSUP 
      INTEGER     VAREF,  INPUTJ, LCTS,   CRUCNT, FLTCNT 
      INTEGER ICLP05 
      LOGICAL     ENDOK,CONEND 
      COMMON   /LOGOS/  ADDR,   ADRFLG, CUROP,  NEXTOP, CFLAG 
      COMMON   /LOGOS/  PI,     XBBL,   XA,     XF,     XZERO,  DPVFLG 
      COMMON   /LOGOS/  LC,     LCI,    LODLCI, LODLCV, LDLCVO, MAXLCV 
      COMMON   /LOGOS/  NEXT,   NUMBER, I,      IOTYPE 
      COMMON   /LOGOS/  J,      K,      L,      LABNLX, M,      N 
      COMMON   /LOGOS/  PSYMB,  SYMBOL, TOP,    VALFLG, QVALUE 
      COMMON   /LOGOS/  OPTOPX, OPNXTX, TOPX,   NEXTX 
      COMMON   /LOGOS/  DUMMY,  OVCHN,  PEEKS 
      COMMON   /LOGOS/  LO,     CI,     CO,     LOGICF, LOCSUP 
      COMMON   /LOGOS/  VAREF,  INPUTJ, LCTS,   CRUCNT, FLTCNT 
      COMMON   /LOGOS/  ICLP05 
      COMMON   /LOGOS/  ENDOK,CONEND 
 
      INTEGER  NINE 
      INTEGER  COMMA, SEMIC, PERIOD, COLON, FOR, DOOP, WHILE 
      INTEGER  RBRACE, LBRACE, RETOP, CRUTCH 
      INTEGER  LPAREN, RPAREN, LBK, RBK 
      INTEGER  EQUAL, NEQUAL, GTR, GEQ, LESS, LESSEQ, ARROW 
      INTEGER  PLUS, MINUS, MULT, DIVIDE, MODOP 
      INTEGER  OROP, ANDOP, AOROP, XOROP, AANDOP 
      INTEGER  LSHIFT, RSHIFT, LCYCLE, RCYCLE, ALSHFT, ARSHFT 
      INTEGER  NEG, UPARO, DNARO, COM 
      INTEGER  LOC, GIZZY, QUOTE, ZRL, TEMPL 
      INTEGER  SP, DP, ST, HEX 
      INTEGER  ATSIGN 
      INTEGER  ICLP06 
      COMMON /OPERS/     NINE 
      COMMON /OPERS/     COMMA, SEMIC, PERIOD, COLON, FOR, DOOP, WHILE 
      COMMON /OPERS/     RBRACE, LBRACE, RETOP, CRUTCH 
      COMMON /OPERS/     LPAREN, RPAREN, LBK, RBK 
      COMMON /OPERS/     EQUAL, NEQUAL, GTR, GEQ, LESS, LESSEQ, ARROW 
      COMMON /OPERS/     PLUS, MINUS, MULT, DIVIDE, MODOP 
      COMMON /OPERS/     OROP, ANDOP, AOROP, XOROP, AANDOP 
      COMMON /OPERS/     LSHIFT, RSHIFT, LCYCLE, RCYCLE, ALSHFT, ARSHFT 
      COMMON /OPERS/     NEG, UPARO, DNARO, COM 
      COMMON /OPERS/     LOC, GIZZY, QUOTE, ZRL, TEMPL 
      COMMON /OPERS/     SP, DP, ST, HEX 
      COMMON /OPERS/    ATSIGN 
      COMMON /OPERS/    ICLP06 
 
      INTEGER  AREG,   XREG,   YREG,   NRREGS 
      INTEGER  STATUS (10),    STAREG, STXREG, STYREG 
      INTEGER  REGS (10) 
      INTEGER  ACTREG (2),      ACTLO,  ACTHI 
      INTEGER  NZREG 
      INTEGER ICLP10 
      COMMON   / REGS / AREG,   XREG,   YREG,   NRREGS 
      COMMON   / REGS / STATUS, REGS,   ACTREG, NZREG 
      COMMON   / REGS / ICLP10 
      EQUIVALENCE    (ACTLO,  ACTREG (1)) 
      EQUIVALENCE    (ACTHI,  ACTREG (2)) 
      EQUIVALENCE    (STAREG, STATUS (1)) 
      EQUIVALENCE    (STXREG, STATUS (2)) 
      EQUIVALENCE    (STYREG, STATUS (3)) 
 
      INTEGER     STK (20, 13) 
      INTEGER     NAMEX (40) 
      INTEGER     OPX,    STKSIZ, OCBIT,  FUNBIT, SBIAS 
      INTEGER ICLP14 
      COMMON      /SDEFS/ STK,    OPX,    STKSIZ, OCBIT,  FUNBIT, SBIAS 
      COMMON      /SDEFS/ ICLP14 
      EQUIVALENCE (STK (1,1), NAMEX (1)) 
      EXTERNAL    OLAGN, OLCGN, OLSGN, OLMGN, OLUGN, OLARA, OLARB 
      IF (.NOT. (LOGICF .EQ. 0))GO TO 13000 
 
      CALL FAULTP (4) 
      RETURN 
13000 CONTINUE 
 
      OP = OPIN 
      LEFT = LEFTIN 
      RIGHT = RIN 
      IF (.NOT. (OP .EQ. -2))GO TO 13002 
 
      INTBR = LEFT 
      RETURN 
13002 CONTINUE 
 
      IF (.NOT. (OP .EQ. -1))GO TO 13004 
 
      LSTKX = LEFT + 2 
      RSTKX = RIGHT + 2 
      RETURN 
13004 CONTINUE 
 
    1 THIS = LOW 
      OTHER = HI 
      SIDE = LEFT 
      EZSTA = .FALSE. 
      MORE  = .FALSE. 
      CALL DUMST ('GEN0') 
      BASE = OP - EQUAL + 1 
      GO TO (  100, 100, 100, 100, 100, 100, 600, 200, 200, 500, 500, 50
     10, 6,   6, 200, 200, 200, 300, 300, 300, 300, 300, 300, 400, 400, 
     1400, 400, 200  ), BASE 
 
    6 CALL FATAL (6) 
  100 CONTINUE 
      CALL CGEN 
      GO TO 1000 
  200 CONTINUE 
      CALL AGEN 
      GO TO 1000 
  300 CONTINUE 
      CALL SGEN 
      GO TO 1000 
  400 CONTINUE 
      CALL UGEN 
      GO TO 1000 
  500 CONTINUE 
      CALL MGEN 
      GO TO 1000 
  600 CONTINUE 
      CALL ARAGEN 
      IF (.NOT. (MORE))GO TO 13006 
 
      CONTINUE 
      CALL ARBGEN 
      IF (MORE) GO TO 600 
13006 CONTINUE 
 
 1000 IF (MORE) GO TO 1 
      DO  13008 I = 4, NRREGS 
      TS = STATUS (I) 
      IF (TS .EQ. LEFTIN .OR. TS .EQ. LEFTIN + STKSIZ .OR. TS .EQ. RIN .
     1OR. TS .EQ. RIN + STKSIZ) STATUS (I) = 0 
13008 CONTINUE 
 
      RETURN 
      END