CD Actual 15

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Assembly Source File | 1991-10-29 | 15.9 KB | 543 lines

;----------------------------------------------------------------------- TITLE PRIMES ; (c) 1991 W.C. Parke ;----------------------------------------------------------------------- CR EQU 13 LF EQU 10 ;----------------------------------------------------------------------- START SEGMENT ASSUME CS:START,DS:START,ES:START,SS:START ORG 100H PUBLIC FIRST,BEGIN FIRST: JMP BEGIN CPWP DB 'Primes V1.4 (c) W.C. Parke, 1991$',1AH EVEN PUBLIC NPRINT1,NPRINT2,NLINE,NPRIME,NPRIME2,TLINE,PBUF,EXTRA,NPS,NP$ PUBLIC CRLF,NUMBUF NPRINT1 DW 1 NPRINT12 DW 0 NPRINT2 DW 0 NPRINT22 DW 0 NLINE DW 8 NPRIME DW 0 NPRIME2 DW 0 TLINE DW 9 PBUF DW 0 EXTRA DB 0 NPS DB CR,LF,'The number of primes was ' NP$ DB '0000000000$' ERROR DB CR,LF,'Error in ' DHELP DB 'Syntax: PRIMES n1 n2' DB CR,LF,CR,LF,' where 0 < n1 < n2 < 1048576' CRLF DB CR,LF,'$' STSI DW 0 LSTB DW 0 INIM DB 0 ERIN DB 0 FLG DB 0 ;----------------------------------------------------------------------- PUBLIC EXIT ; Process error message and exit EXITE: MOV DX,OFFSET ERROR EXITH: MOV AH,9 INT 21H MOV AX,4C00H INT 21H EXIT: PUSH CS POP ES MOV AL,ERIN AND AL,AL JNZ EXITE MOV AX,NPRIME MOV DX,NPRIME2 MOV DI,OFFSET NP$ PUSH DI CALL BINDEC32 POP SI CMP BYTE PTR NP$+9,' ' JNZ EXIT1 MOV BYTE PTR NP$+9,'0' EXIT1: MOV DX,OFFSET NPS MOV AH,9 INT 21H CALL SCRLF MOV AL,0 MOV AH,4CH INT 21H HELP: CALL SCRLF MOV DX,OFFSET DHELP JMP EXITH ;----------------------------------------------------------------------- PUBLIC BEGIN ; Begin by getting command line numbers BEGIN: CALL SCRLF MOV DX,OFFSET CPWP MOV AH,9 INT 21H CALL SCRLF MOV SI,OFFSET 81H MOV DI,OFFSET NUMBUF CALL GETNUM JNC BEG1 MOV ERIN,1 JMP EXIT BEG1: JCXZ BEG2 PUSH SI MOV SI,OFFSET NUMBUF MOV DI,OFFSET NPRINT1 CALL DECBIN32 POP SI MOV DI,OFFSET NUMBUF CALL GETNUM BEG2: JCXZ BEG3 MOV SI,OFFSET NUMBUF MOV DI,OFFSET NPRINT2 CALL DECBIN32 BEG3: MOV CX,NPRINT2 MOV DX,NPRINT2+2 ; dx:cx = second number MOV SI,NPRINT1 MOV AX,NPRINT1+2 ; ax:si = first number MOV BX,SI ; table index = 16*si + 2*b + 1 OR BX,AX JZ HELP MOV BX,CX OR BX,DX JZ HELP TEST DX,0FFF0H JNZ BEG4 TEST AX,0FFF0H JNZ BEG4 AND AX,AX JNZ BEG31 CMP SI,3 JNC BEG31 MOV SI,1 MOV FLG,1 BEG31: MOV DI,DX ; nprint22 MOV BX,CX ; nprint2 SUB BX,SI ; nprint2-nprint1 SBB DI,AX ; nprint22-nprint12-c JNC BEG5 BEG4: MOV ERIN,1 JMP EXIT BEG5: OR BX,DI JZ BEG4 OR SI,1 ; make nprint1 odd TEST CX,1 JNZ BEG6 ; odd already SUB CX,1 SBB DX,0 ; get next lower odd BEG6: MOV BX,SI ; nprint1 AND BX,0FH ; start to print after div by 16 SHR BX,1 ; get bit index for starting number SHR AX,1 ; divide first number by 16 RCR SI,1 SHR AX,1 RCR SI,1 SHR AX,1 RCR SI,1 SHR AX,1 RCR SI,1 ; si now has [#/16] MOV STSI,SI MOV AX,CX ; nprint2 AND AX,0FH ; extra to print SHR AX,1 ; but only odds MOV EXTRA,AL SHR DX,1 ; divide second number by 16 RCR CX,1 SHR DX,1 RCR CX,1 SHR DX,1 RCR CX,1 SHR DX,1 RCR CX,1 MOV DX,CX ; save index of last byte-mask to print MOV LSTB,DX ; last byte ptr ; Extimate square root of last byte using ; 2**(k-1) + #/2**(k+1) ; where k is largest integer for which # ~ 2**2k MOV AX,CX MOV CX,16 BEG7: SHL AX,1 JC BEG8 LOOP BEG7 BEG8: SHR CX,1 ; k MOV AX,1 SHL AX,CL ; 2**k INC CX ; k+1 SHR DX,CL ; #/2**(k+1) SHR AX,1 ; 2**(k-1) ADD DX,AX INC DX MOV BP,DX ; save for later comparison MOV CX,BX AND CL,7 MOV AL,1 SHL AL,CL ; get initial mask MOV INIM,AL MOV AX,OFFSET STK MOV SP,AX ; set up our stack MOV BX,OFFSET BUF PUSH DS POP AX ADD BX,15 SHR BX,1 SHR BX,1 SHR BX,1 SHR BX,1 ADD AX,BX MOV PBUF,AX ; the prime bit buffer ASSUME ES:NOTHING,DS:NOTHING MOV ES,AX MOV DS,AX XOR AX,AX MOV SI,AX MOV DI,AX MOV CX,32768 REP STOSW ; zero 64K buffer MOV BX,1 ; bit tester register will be BL MOV CH,8 ; CH=8, CL bit pointer PUSH CX PUSH SI ; address in buffer ;----------------------------------------------------------------------- PUBLIC NEXTP ; Start Eratosthenes sieve NEXTP: POP SI ; byte pointer POP CX ; bit counter NEXTP1: INC CL ; pointer in 8 bits ROL BL,1 ; bit mask, 8 bit roll and set C JNC NEXTP2 ; not yet finished with byte XOR CL,CL ; reset bit pointer INC SI ; point to next byte in buffer CMP SI,BP ; are we finished? JNC FINS2 ; yes PUBLIC NEXTP2 NEXTP2: MOV AL,[SI] ; get byte AND AL,BL ; is it a prime, i.e. still a zero bit ? JNZ NEXTP1 ; no, its bit is set to 1, its not prime PUSH CX ; save bit counter PUSH SI ; save byte pointer MOV DI,SI ; put prime byte index in di MOV DL,CL ; put prime bit index in dl SHL DI,1 ; since we are doing only odds, double first JC NEXTP ; more than half done SHL DL,1 ; double bit index also INC DL ; and add 1 to make 2*i+1 CMP DL,CH ; bigger than 8 ? JC DELN ; no SUB DL,CH ; reset bit index: DL - 8 INC DI ; point to next byte index JZ NEXTP DELN: ADD SI,DI ; point to next non-prime byte JC NEXTP ADD CL,DL ; point to next non-prime bit in byte CMP CL,CH JC DELN1 SUB CL,CH INC SI JZ NEXTP DELN1: MOV AL,1 SHL AL,CL OR [SI],AL ; mask this bit to show non-prime JMP SHORT DELN ;----------------------------------------------------------------------- PUBLIC FINS2 ; Now print all flagged (prime) bits up to requested number FINS2: PUSH CS POP DS ASSUME DS:START MOV DI,OFFSET NP$ MOV CX,LSTB ; last byte pointer MOV SI,STSI ; initial byte pointer MOV AL,INIM ; initial mask TEST FLG,1 JZ FINS21 DEC TLINE MOV AX,2 XOR DX,DX MOV BP,AX CALL PRT3 MOV AX,BP FINS21: CMP CX,SI JZ FINS5 FINS3: MOV AH,AL AND AH,ES:[SI] MOV BP,AX JNZ FINS4 CALL PRINT FINS4: MOV AX,BP ROL AL,1 JNC FINS3 INC SI CMP SI,CX JC FINS3 JZ FINS5 MOV ERIN,0 JMP EXIT FINS5: XOR CX,CX MOV CL,EXTRA JCXZ FINS9 MOV CH,1 SHL CH,CL MOV CL,CH ROL CL,1 FINS6: MOV AH,AL AND AH,ES:[SI] MOV BP,AX JNZ FINS8 CALL PRINT FINS8: MOV AX,BP ROL AL,1 CMP AL,CL JNZ FINS6 FINS9: MOV ERIN,0 JMP EXIT PUBLIC PRINT PRINT: DEC TLINE ; # on line JNZ PRT1 CALL PRTCR PRT1: MOV BH,AL XOR DX,DX MOV AX,SI SHL AX,1 RCL DX,1 SHL AX,1 RCL DX,1 SHL AX,1 RCL DX,1 SHL AX,1 RCL DX,1 MOV BL,0 PRT2: INC BL ROR BH,1 JNC PRT2 XOR BH,BH SHL BX,1 DEC BX ADD AX,BX ADC DX,0 PRT3: ADD WORD PTR NPRIME,1 ADC WORD PTR NPRIME2,0 ;----------------------------------------------------------------------- PUBLIC OUTDEC ; Output a decimal number OUTDEC: PUSH AX PUSH CX PUSH DI PUSH DX PUSH ES PUSH CS POP ES MOV DI,OFFSET NP$ CALL BINDEC32 XCHG SI,DI ADD SI,2 MOV AH,2 MOV CX,8 OUTDS: LODSB MOV DL,AL INT 21H LOOP OUTDS XCHG SI,DI POP ES POP DX POP DI POP CX POP AX RET ;----------------------------------------------------------------------- PUBLIC PRTCR ; Print a carriage return and line feed and reset number/line count PRTCR: PUSH AX CALL SCRLF MOV AX,NLINE MOV TLINE,AX POP AX RET ;----------------------------------------------------------------------- PUBLIC CKNUM ; Check if character is a number CKNUM: CMP AL,':' CMC JC CKNE CMP AL,'0' CKNE: RET ;----------------------------------------------------------------------- PUBLIC GETNUM ; Get an ASCII number GETNUM: CALL SKIPS XOR CX,CX GETN1: LODSB CMP AL,CR JZ GETNE CMP AL,' ' JZ GETNE CALL CKNUM JC GETNC INC CX STOSB JMP SHORT GETN1 GETNC: RET GETNE: CMP CX,8 CMC RET ;----------------------------------------------------------------------- PUBLIC DECBIN32 ; Convert a decimal number to 32 bit binary number DECBIN32: PUSH DI PUSH BP PUSH BX XOR AX,AX ; zero initial MOV DX,AX ; binary double word MOV BX,AX ; and our decimal digit holder MOV BP,10 ; multiplier JMP DECBS ; skip first multiplication DECBL: XCHG DI,AX ; save current low word MOV AX,DX ; get high word MUL BP ; mult high word by 10 XCHG DI,AX ; save and get low word MUL BP ; mult low word by 10 ADD DX,DI ; add 10*hi to overflow of 10*lo DECBS: MOV BL,[SI] ; get next decimal INC SI ; bump buffer pointer SUB BL,30H ; drop ascii bias ADD AX,BX ; add next decimal to low word ADC DX,0 ; and carry to high word LOOP DECBL ; continue for 10 digits POP BX POP BP POP DI STOSW MOV AX,DX STOSW RET ;----------------------------------------------------------------------- PUBLIC SKIPS ; Skip space characters in a string SKIPS: CMP BYTE PTR [SI],' ' JNZ SKIPE INC SI JMP SHORT SKIPS SKIPE: RET ;----------------------------------------------------------------------- PUBLIC SCRLF ; Send a carriage return and line feed SCRLF: PUSH DX MOV DX,OFFSET CRLF MOV AH,9 INT 21H POP DX RET ;----------------------------------------------------------------------- PUBLIC BINDEC32 ; Convert 32 bit binary to decimal BINDEC32: ; Convert 32 bit number to decimal PUSH BX ; save bx PUSH CX ; save cx PUSH SI ; save si PUSH DI ; save buffer pointer MOV DI,DX ; save binary double word MOV SI,AX ; in DI,SI XOR AX,AX ; zero high decimal accumulator MOV BX,AX ; BX will hold high packed BCD MOV DX,AX ; DX will hold low packed BCD MOV CX,32 ; use all 32 bits of double word BIND1: SHL SI,1 ; shift low word left RCL DI,1 ; rotate hi word left through carry XCHG DX,AX ; use DX low 4 digits first ADC AL,AL ; add al to al with carry bit DAA ; decimal adj al XCHG AL,AH ; now do the same with ah ADC AL,AL ; double and add carry DAA ; decimal adj XCHG AL,AH ; restore ax order XCHG DX,AX ; save resultant low BCD quartet XCHG BX,AX ; now use BX high 4 digits ADC AL,AL ; add al to al with carry bit DAA ; decimal adj al XCHG AL,AH ; now do the same with ah ADC AL,AL ; double and add carry DAA ; decimal adj XCHG AL,AH ; restore ax order XCHG BX,AX ; save resultant high BCD quartet ADC AL,AL ; accum highest digits in AL DAA ; as a pair of BCDs LOOP BIND1 ; do all 32 bits MOV SI,OFFSET TMPBUF ; our temporary buffer for packed BCD POP DI ; get buffer pointer PUSH DI ; save again MOV [SI],BX ; middle word MOV [SI+2],DX ; low word MOV CX,1 ; local count MOV DX,3 ; anticipate two more words to unpack MOV AH,AL ; save nibble pair JMP SHORT UNPL ; start with first nibble pair BINDU: ; expand packed BCD to ascii string XCHG DX,CX ; save external count LODSW ; get packed BCD word MOV CX,2 ; local count MOV BX,AX ; save ax MOV AL,AH ; start with ah UNPL: SHR AL,1 ; shift hi nibble SHR AL,1 ; note that four 1 bit shifts are SHR AL,1 ; 8 clock cycles, while shr al,cl(4) SHR AL,1 ; takes 24 clock cycles OR AL,30H ; add ascii bias STOSB ; save MOV AL,AH ; get back ah AND AL,0FH ; mask lo nibble OR AL,30H ; add ascii bias STOSB ; save MOV AX,BX ; get back word MOV AH,AL ; save low byte LOOP UNPL ; local loop XCHG CX,DX ; restore external count LOOP BINDU ; finish all packed BCDs POP DI ; recover buffer pointer POP SI ; old saved si POP CX POP BX ;----------------------------------------------------------------------- PUBLIC BLANK ; Replace leading zeros by space BLANK: PUSH DI BLANKL: CMP BYTE PTR [DI],'0' JNZ BLANKE MOV BYTE PTR [DI],' ' INC DI JMP SHORT BLANKL BLANKE: POP DI RET TMPBUF DW 2 DUP(0) EVEN STK EQU $+256 BUF EQU STK+4 NUMBUF EQU BUF START ENDS END FIRST ;-----------------------------------------------------------------------