S-C Macro Assembler 3.0 -- ASM2/X.EXPRESSION.C
1000 *SAVE X.EXPRESSION.C
1010 *--------------------------------
1020 * EXPRESSION CRACKER
1030 *-------------------------------
1040 EXPR.DEFINED
1050 JSR EXPR
1060 BMI .1
1070 RTS
1080 .1 JMP UNDF
1090 *--------------------------------
1100 OPERATOR.CHARS
1110 .AS "^!|&<=>/*)], "
1120 OPERATOR.CHARS.SIZE .EQ *-OPERATOR.CHARS
1130 *--------------------------------
1140 OPERATOR.INDEX
1150 .HS 0C.0A.0A.08.0E.10.12.06.04.FF.FF.FF.FF
1160 * ^ ! | & < = > / * ) ] , SPC
1170 *--------------------------------
1180 OPERATOR.TABLE
1190 .DA EXP.SUBTRACT-1 0 FOR -<=>
1200 .DA EXP.ADD-1 2 FOR +
1210 .DA EXP.MULTIPLY-1 4 FOR *
1220 .DA EXP.DIVIDE-1 6 FOR /
1230 .DA EXP.AND-1 8 FOR &
1240 .DA EXP.ORA-1 A FOR !|
1250 .DA EXP.EOR-1 C FOR ^
1260 .DA EXP.LESS-1 E FOR <
1270 .DA EXP.EQUAL-1 10 FOR =
1280 .DA EXP.GREATER-1 12 FOR >
1290 *--------------------------------
1300 ERBA3 JMP ERBA
1310 *--------------------------------
1320 EXPR JSR GNNB GET NEXT NON-BLANK
1330 BCS ERBA3 NO EXPRESSION ON LINE
1340 JSR BACKUP.CHAR.PNTR
1350 *--------------------------------
1360 EXP1 JSR ZERO.EXP.VALUE
1370 STA EXP.NEW NEW EXPRESSION FLAG = 0
1380 STA EXP.UNDEF ZERO UNDEF FLAG
1390 LDX #$40 INIT FWD REF FLAG
1400 STX EXP.FWDREF
1410 *--------------------------------
1420 EXP2 LDX #0 SET OPERATOR=0 FOR +
1430 JSR GNC.UC
1440 BCS .3 END OF LINE
1450 CMP #'- MINUS
1460 BEQ .6 X=0 FOR MINUS OR RELOPS
1470 LDX #2 X=2 FOR ADDITION
1480 CMP #'+ ADD
1490 BEQ .6
1500 LDY EXP.NEW NOT + OR -
1510 BEQ .7 BUT IT IS NEW EXPR
1520 LDX #OPERATOR.CHARS.SIZE-1
1530 .1 LDA OPERATOR.CHARS,X
1540 CMP CURRENT.CHAR
1550 BEQ .2
1560 DEX
1570 BPL .1
1580 JMP ERBA
1590 *---FOUND OP OR TERM CHAR--------
1600 .2 LDA OPERATOR.INDEX,X
1610 BPL .5 ...OPERATOR
1620 *---END OF EXPRESSION-----------
1630 JSR BACKUP.CHAR.PNTR
1640 .3 LDY EXP.UNDEF UNDEF FLAG
1650 BPL .4
1660 JSR ZERO.EXP.VALUE
1670 TYA RECOVER UNDEF STATUS
1680 .4 RTS
1690 *--------------------------------
1700 .5 TAX
1710 .6 JSR GNC.UC
1720 .7 INC EXP.NEW NOT A NEW EXPRESSION ANYMORE
1730 LDA OPERATOR.TABLE+1,X
1740 PHA
1750 LDA OPERATOR.TABLE,X
1760 PHA
1770 *-------------------------------
1780 * GET OPERAND
1790 *-------------------------------
1800 GET.OPERAND
1810 JSR ZERO.SYM.VALUE
1820 LDA CURRENT.CHAR
1830 CMP #$30 FIRST CHAR OF OPERAND
1840 BCC .3 PUNCTUATION
1850 CMP #$3A
1860 BCS .2 MIGHT BE LETTER, TRY LABEL
1870 JSR DECN CONVERT DECIMAL NUMBER
1880 .15 JMP BACKUP.CHAR.PNTR
1890 *---TRY A LABEL------------------
1900 .2 JSR PACK TRY LABEL
1910 BCC .4 NO GOOD
1920 JSR STSRCH LOOK UP THE VALUE
1930 LDY #6 UPDATE FWD REF FLAG
1940 >SYM LDA,STPNTR
1950 AND EXP.FWDREF
1960 STA EXP.FWDREF
1970 BCC .1 DEFINED LABEL
1980 ROR EXP.UNDEF UNDEFINED, MAKE FLAG NEGATIVE
1990 .1 RTS
2000 *---TRY LOCAL LABEL--------------
2010 .3 CMP #'.
2020 BEQ .2 LOCAL LABEL
2030 *---TRY CONSTANTS----------------
2040 LDX #3 3-->HEX CONSTANT
2050 CMP #'$
2060 BEQ .5 HEX CONSTANT
2070 DEX 2-->OCT CONSTANT
2080 CMP #'&'
2090 BEQ .5 ...OCTAL
2100 LDX #0 0-->BIN CONSTANT
2110 CMP #'% BINARY CONSTANT
2120 BEQ .5 ...BINARY
2130 *---TRY LITERALS-----------------
2140 CMP #'' (X = 0)
2150 BEQ .6 LITERAL
2160 CMP #'" LITERAL WITH HIGH BIT SET
2170 BEQ .9
2180 *---TRY STAR---------------------
2190 CMP #'*
2200 BNE .4 ...NONE OF THE ABOVE, ERROR
2210 LDX #3 VALUE IS CURRENT LOCATION
2220 .7 LDA ORGN,X
2230 STA SYM.VALUE,X
2240 DEX
2250 BPL .7
2260 RTS
2270 *---INVALID OPERAND--------------
2280 .4 JMP ERBA BAD ADDRESS ERROR
2290 *---HEX/OCT/BIN CONSTANT--------
2300 .5 JSR HEX.OCT.BIN.DGT $ABCD, &777, %1010
2310 BCC .4 NO, ERROR BAD ADDRESS
2320 .8 JSR HEX.OCT.BIN.DGT.1 GET ANOTHER DIGIT
2330 BCS .8
2340 BCC .15 ...ALWAYS
2350 *---TICK & QUOTE LITERALS-------
2360 .9 LDX #$80 HIBIT=1
2370 .6 STX SYM.VALUE
2380 STA DGTCNT SAVE ' OR " FOR OPTIONAL TERMCHAR
2390 JSR GNC GET FOLLOWING CHAR
2400 BCS .4 END OF LINE
2410 ORA SYM.VALUE SET HIGH BIT
2420 STA SYM.VALUE
2430 JSR GNC SEE IF CLOSING QUOTE
2440 CMP DGTCNT (IT IS OPTIONAL)
2450 BNE .15 NO, BACK UP CHAR PNTR
2460 RTS
2470 *-------------------------------
2480 * IF NEXT CHAR IS VALID DIGIT,
2490 * APPEND IT TO CURRENT VALUE
2500 *
2510 * (X) DETERMINES BASE: 0-->2, 2-->8, 3-->16
2520 *-------------------------------
2530 HEX.DIGIT
2540 LDX #3
2550 HEX.OCT.BIN.DGT
2560 STX BASE.INDEX
2570 HEX.OCT.BIN.DGT.1
2580 .1 JSR GNC.UC IGNORE CASE
2590 CMP #'.' ALLOW PERIODS
2600 BEQ .1 ...BUT IGNORE THEM
2610 EOR #$30
2620 CMP #$0A
2630 BCC .3 ...0-9, TEXT VALIDITY
2640 ADC #$88 ...MIGHT BE A...F
2650 .2 CMP #$FA
2660 BCC .5 NOT A-F EITHER, RETURN CARRY CLEAR
2670 AND #$0F TRIM HEX A...F
2680 .3 LDX BASE.INDEX
2690 CMP BASE.TABLE,X CHECK REAL RANGE
2700 BCS .2 ...NOT VALID, CLR CARRY WITH 'CMP #$FA'
2710 PHA SAVE DIGIT
2720 .4 JSR ASL.SYM.VALUE
2730 DEX MAKE ROOM FOR DIGIT
2740 BPL .4
2750 PLA GET DIGIT
2760 ORA SYM.VALUE MERGE WITH PREVIOUS
2770 STA SYM.VALUE
2780 SEC FLAG GOT A DIGIT
2790 .5 RTS
2800 *--------------------------------
2810 BASE.TABLE
2820 .DA #2,#2,#8,#16
2830 ASL.SYM.VALUE
2840 CLC
2850 ROL.SYM.VALUE
2860 ROL SYM.VALUE
2870 ROL SYM.VALUE+1
2880 ROL SYM.VALUE+2
2890 ROL SYM.VALUE+3
2900 RTS
2910 *--------------------------------
2920 ZERO.EXP.VALUE
2930 LDA #0
2940 STA EXP.VALUE
2950 STA EXP.VALUE+1
2960 STA EXP.VALUE+2
2970 STA EXP.VALUE+3
2980 RTS
2990 *--------------------------------
3000 ZERO.EXP.VALUE64
3010 LDA #0
3020 STA EXP.VALUE64
3030 STA EXP.VALUE64+1
3040 STA EXP.VALUE64+2
3050 STA EXP.VALUE64+3
3060 RTS
3070 *--------------------------------
3080 ZERO.SYM.VALUE
3090 LDA #0
3100 STA SYM.VALUE
3110 STA SYM.VALUE+1
3120 STA SYM.VALUE+2
3130 STA SYM.VALUE+3
3140 RTS
3150 *--------------------------------
3160 EXP.AND
3170 LDX #3
3180 .1 LDA EXP.VALUE,X
3190 AND SYM.VALUE,X
3200 STA EXP.VALUE,X
3210 DEX
3220 BPL .1
3230 JMP EXP2
3240 *--------------------------------
3250 EXP.ORA
3260 LDX #3
3270 .1 LDA EXP.VALUE,X
3280 ORA SYM.VALUE,X
3290 STA EXP.VALUE,X
3300 DEX
3310 BPL .1
3320 JMP EXP2
3330 *--------------------------------
3340 EXP.EOR
3350 LDX #3
3360 .1 LDA EXP.VALUE,X
3370 EOR SYM.VALUE,X
3380 STA EXP.VALUE,X
3390 DEX
3400 BPL .1
3410 JMP EXP2
3420 *--------------------------------
3430 EXP.ADD
3440 CLC PLUS
3450 LDX #-4
3460 .1 LDA EXP.VALUE+4,X
3470 ADC SYM.VALUE+4,X
3480 STA EXP.VALUE+4,X
3490 INX
3500 BNE .1
3510 JMP EXP2
3520 *--------------------------------
3530 EXP.SUBTRACT
3540 JSR EXP.SUBTRACTION
3550 JMP EXP2
3560 *--------------------------------
3570 EXP.SUBTRACTION
3580 SEC
3590 LDX #-4
3600 .7 LDA EXP.VALUE+4,X
3610 SBC SYM.VALUE+4,X
3620 STA EXP.VALUE+4,X
3630 INX
3640 BNE .7
3650 RTS
3660 *--------------------------------
3670 EXP.LESS
3680 JSR EXP.SUBTRACTION
3690 LDA EXP.VALUE+3
3700 BMI EXP.TRUE
3710 EXP.FALSE
3720 CLC
3730 EXP.TRUE.OR.FALSE
3740 JSR ZERO.EXP.VALUE
3750 ROL EXP.VALUE
3760 JMP EXP2
3770 *--------------------------------
3780 EXP.EQUAL
3790 JSR EXP.SUBTRACTION
3800 JSR TEST.EXP.VALUE
3810 BNE EXP.FALSE
3820 EXP.TRUE
3830 SEC
3840 BCS EXP.TRUE.OR.FALSE
3850 *--------------------------------
3860 TEST.EXP.VALUE.ZP
3870 LDA #0
3880 .HS 2C
3890 TEST.EXP.VALUE
3900 LDA EXP.VALUE
3910 ORA EXP.VALUE+1
3920 ORA EXP.VALUE+2
3930 ORA EXP.VALUE+3
3940 RTS
3950 *--------------------------------
3960 EXP.GREATER
3970 JSR EXP.SUBTRACTION
3980 JSR TEST.EXP.VALUE
3990 BEQ EXP.FALSE
4000 LDA EXP.VALUE+3 LOOK AT SIGN BIT
4010 BMI EXP.FALSE
4020 BPL EXP.TRUE
4030 *-------------------------------
4040 EXP.DIVIDE
4050 JSR EXP.DIVISION
4060 JMP EXP2
4070 *--------------------------------
4080 EXP.DIVISION
4090 JSR ZERO.EXP.VALUE64
4100 LDY #32 32 BITS
4110 .1 ASL EXP.VALUE SHIFT DIVIDEND/QUOTIENT LEFT
4120 ROL EXP.VALUE+1
4130 ROL EXP.VALUE+2
4140 ROL EXP.VALUE+3
4150 ROL EXP.VALUE64 SHIFT PARTIAL DIVIDEND LEFT
4160 ROL EXP.VALUE64+1
4170 ROL EXP.VALUE64+2
4180 ROL EXP.VALUE64+3
4190 SEC SUBTRACT DIVISOR FROM PARTIAL DIVIDEND
4200 LDA EXP.VALUE64
4210 SBC SYM.VALUE
4220 PHA SAVE LO-BYTE OF DIFFERENCE ON STACK
4230 LDA EXP.VALUE64+1
4240 SBC SYM.VALUE+1
4250 PHA
4260 LDA EXP.VALUE64+2
4270 SBC SYM.VALUE+2
4280 PHA
4290 LDA EXP.VALUE64+3
4300 SBC SYM.VALUE+3
4310 BCC .2 REMAINDER TOO SMALL
4320 INC EXP.VALUE SET BIT IN QUOTIENT
4330 STA EXP.VALUE64+3 HI-BYTE OF REMAINDER
4340 PLA RETRIEVE NEXT BYTE OF REMAINDER
4350 STA EXP.VALUE64+2
4360 PLA
4370 STA EXP.VALUE64+1
4380 PLA
4390 STA EXP.VALUE64
4400 BCS .3
4410 .2 PLA STACK BACK TO NORMAL
4420 PLA
4430 PLA
4440 .3 DEY NEXT BIT
4450 BNE .1
4460 RTS
4470 *--------------------------------
4480 EXP.MULTIPLY
4490 JSR ZERO.EXP.VALUE64
4500 LDY #32 32-BIT MULTIPLY
4510 .1 LDA EXP.VALUE CHECK LSB OF MULTIPLIER
4520 LSR
4530 BCC .2 IF 0, DON'T ADD MULTIPLICAND
4540 CLC ADD MULTIPLICAND
4550 LDA EXP.VALUE64
4560 ADC SYM.VALUE
4570 STA EXP.VALUE64
4580 LDA EXP.VALUE64+1
4590 ADC SYM.VALUE+1
4600 STA EXP.VALUE64+1
4610 LDA EXP.VALUE64+2
4620 ADC SYM.VALUE+2
4630 STA EXP.VALUE64+2
4640 LDA EXP.VALUE64+3
4650 ADC SYM.VALUE+3
4660 STA EXP.VALUE64+3
4670 .2 ROR EXP.VALUE64+3
4680 ROR EXP.VALUE64+2
4690 ROR EXP.VALUE64+1
4700 ROR EXP.VALUE64
4710 ROR EXP.VALUE+3
4720 ROR EXP.VALUE+2
4730 ROR EXP.VALUE+1
4740 ROR EXP.VALUE
4750 DEY
4760 BNE .1
4770 JMP EXP2
4780 *-------------------------------
4790 * MGO COMMAND
4800 *-------------------------------
4810 MGO JSR EXPR.DEFINED CRACK EXPRESSION
4820 JMP (EXP.VALUE) ENTER USER'S PROGRAM
4830 *--------------------------------
4840 * VAL COMMAND
4850 *--------------------------------
4860 VAL JSR EXPR.DEFINED GET VALUE OF EXPRESSION
4870 LDA #'$'
4880 JSR CHO
4890 JSR P.EXP.VALUE
4900 LDA #'='
4910 JSR CHO
4920 JSR ZERO.SYM.VALUE
4930 TAX X=0
4940 LDA #10
4950 STA SYM.VALUE
4960 .1 JSR EXP.DIVISION
4970 LDA EXP.VALUE64 REMAINDER
4980 PHA
4990 INX
5000 JSR TEST.EXP.VALUE
5010 BNE .1
5020 .2 PLA
5030 ORA #'0'
5040 JSR CHO
5050 DEX
5060 BNE .2
5070 JMP CRLF
5080 *--------------------------------
