试管 补佳乐:急!!!!!怎样用汇编求圆周率

这个啊，有点复杂, 基本算法如下(里面有几个用于输入输出和转换的函数，不过不影响基本算法)

386
CODE SEGMENT USE16
ASSUME CS:CODE,DS:CODE
ORG 100H
start:
jmp install

HANDLE DW ?
_MIN DW ?
_SEC DW ?
_SEC1 DW ?
_A DD ?
_B DD ?
_FS_POINT DW 0
_GS_POINT DW 0
_DIV DD 1
FLAG DB ? ;=1 +
DIGITAL DD 5000 ;how many points want to calculate
POINT DW ? ;total point /5
NUM_POINT DW ? ;total point /5 * 4
_COUNT DD ?
TMP_NUM0 DD ?
TMP_NUM DD 10 dup (?)
KEY_BUFF DB 6,0,6 dup (0)

D_SAVE DB 'Saving result to file %c ...',0
DW 80h
D_SAVE_OK DB 8,8,8,8,', OK !',0dh,0ah,0
D_SAVE_ERR DB 8,8,8,8,', error !',0dh,0ah,0

D_TIME DB 0dh,0ah,'Total %ld points, time used %d:%02d.%03d, '
db 'calculate %ld times.',0dh,0ah,0
dw digital,_min,_sec,_sec1,_div
D_SCAN DB '<<PI calculater>> Dec 18, 1996',0dh,0ah
DB 'Copyright(C) by Luo Yun Bin, phone 0576-4114689',0dh,0ah,0ah
DB 'How many points (10-80000): ',0
D_ABORT DB 'User pressed Esc, calculate aborted !%20r ',0dh,0ah,0
D_CAL DB 'Calculating, please waiting ... (Esc to cancel)',0dh,0
D_CAL1 DB '%d %% calculated, please waiting ... (Esc to cancel)',0dh,0
DW PERCENT
PERCENT DW ?
D_STR1 DB ' PI = %1ld.%c',0dh,0ah,0
DW tmp_num0,d_sub_str
D_STR2 DB '%5ld : %c'
DB 0dh,0ah,0
DW _count,d_sub_str
D_SUB_STR DB '%05ld %05ld %05ld %05ld %05ld '
DB '%05ld %05ld %05ld %05ld %05ld',0
DW tmp_num,tmp_num+4,tmp_num+8,tmp_num+12,tmp_num+16
DW tmp_num+20,tmp_num+24,tmp_num+28,tmp_num+32,tmp_num+36

install:
mov si,offset d_scan
call printf
mov ah,0Ah
mov dx,offset key_buff
int 21h
mov si,offset key_buff+2
call scanf
mov eax,dword ptr scan_num
mov digital,eax
mov si,offset d_cal
call printf

xor ax,ax
mov ds,ax
mov ax,ds:[046ch]
push cs
pop ds
mov _sec,ax

mov ax,cs
add ax,1000h ;result of 4*4*5/25^n
mov fs,ax
add ax,1000h ;result of 4*239/57121^n
mov gs,ax
add ax,1000h ;total result
mov bp,ax

mov ax,fs
call init_num
mov dword ptr fs:[4],4*239*100000

mov ax,gs
call init_num
mov dword ptr gs:[4],4*4*5*100000

mov ax,bp
call init_num

call pre
call calc

xor ax,ax
mov ds,ax
mov ax,ds:[046ch]
push cs
pop ds
mov _sec1,ax

push point
call num_out
pop point

mov ax,_sec1
sub ax,_sec
mov cx,55
mul cx
mov cx,1000
div cx
mov _sec1,dx
mov cx,60
xor dx,dx
div cx
mov _min,ax
mov _sec,dx
mov si,offset d_time
call printf

mov si,81h
mov di,80h
cmd_lop:
lodsb
cmp al,0dh
jz cmd_end
cmp al,20h
jbe cmd_lop
cmp al,'a'
jb cmd_store
cmp al,'z'
ja cmd_store
sub al,20h
cmd_store:
stosb
jmp short cmd_lop
cmd_end:
xor al,al
stosb

mov si,80h
cmp byte ptr ds:[si],0
jz quit

mov si,offset d_save
call printf

mov ah,3ch
xor cx,cx
mov dx,80h
int 21h
jb file_err

mov handle,ax
mov std_out,offset write_file
call num_out

mov std_out,offset prt_to_scr
mov si,offset d_save_ok
call printf

mov ah,3eh
mov bx,handle
int 21h
int 20h
file_err:
mov si,offset d_save_err
call printf
int 20h
quit:
int 20h

WRITE_FILE PROC

pusha
mov ah,40h
mov flag,al
mov bx,handle
mov cx,1
mov dx,offset flag
int 21h
popa
ret

WRITE_FILE ENDP

PRE PROC

mov eax,digital ;total 65536*5/4 points
cmp eax,(65536/4-3)*5 ;comp max points
jbe pre_1
mov eax,(65536/4-3)*5
pre_1:
cmp eax,10 ;comp min points
jae pre_2 ;must > 10 and < 81915
mov eax,10
pre_2:
xor edx,edx
mov ecx,5
div ecx
mov ebx,eax
inc ebx
mov point,bx ;point for print control

mul ecx
mov digital,eax ;

mov eax,ebx
inc eax
mov ecx,4
mul ecx
mov num_point,ax ;max used memory

ret

PRE ENDP

CALC PROC

mov es,bp
c_lop0:
mov ah,1
int 16h
jz calc_0
xor ah,ah
int 16h
cmp al,1bh
jnz calc_00
push cs
pop es
mov si,offset d_abort
call printf
int 20h
calc_00:
xor eax,eax
mov ax,_gs_point
mov ecx,500
mul ecx
mov ecx,4
div ecx
xor edx,edx
div digital
mov percent,ax
mov si,offset d_cal1
push cs
pop es
call printf
mov es,bp
calc_0:
xor eax,eax
mov ecx,100000
mov _a,eax
mov _b,eax
xor flag,00000001b ;init part
;============================================================
mov ebx,57121
c_lop1:
mov si,_fs_point ;if 4*5/25^n = 0 skip
cmp si,num_point
jae calc_1
cmp dword ptr fs:[si],0
jnz c_lop2
add _fs_point,4
jmp short c_lop1
c_lop2:
mul ecx
add eax,fs:[si]
adc edx,0
div ebx
mov fs:[si],eax
mov eax,edx

add si,4
cmp si,num_point
jb c_lop2
;=======================================================
calc_1:
mov ebx,25
c_lop3:
mov si,_gs_point ;if 4*5/25^n = 0 skip
cmp si,num_point
jae calc_4
cmp dword ptr gs:[si],0
jnz c_lop4
add _gs_point,4
jmp short c_lop3
c_lop4:
mov eax,_a
mul ecx
add eax,gs:[si]
adc edx,0
div ebx
mov gs:[si],eax
mov _a,edx

mov eax,_b
mul ecx
add eax,gs:[si]
adc edx,0
sub eax,fs:[si]
sbb edx,0

cmp edx,0
jl _t1
div _div
mov _b,edx
jmp short _t2
_t1:
idiv _div
dec eax
add edx,_div
mov _b,edx
_t2:
test flag,00000001b
jnz calc_2
sub es:[si],eax
jmp short calc_3
calc_2:
add es:[si],eax
calc_3:
add si,4
cmp si,num_point
jb c_lop4
c_lop5:
add _div,2
jmp c_lop0
;====================================================
calc_4:
xor eax,eax
mov _a,eax
mov si,num_point
c_lop6:
sub si,4
mov eax,es:[si]
add eax,_a

cmp eax,ecx
jge calc_5
cmp eax,0
jle calc_6
mov _a,0
mov es:[si],eax
jmp short calc_8
calc_5:
xor edx,edx
div ecx
mov es:[si],edx
mov _a,eax
jmp short calc_8
calc_6:
mov edx,-1
idiv ecx
dec eax
add edx,ecx
mov es:[si],edx
mov _a,eax
calc_8:
cmp si,4
ja c_lop6

mov eax,_a
mov es:[0],eax

push cs
pop es
ret

CALC ENDP

INIT_NUM PROC

push es
mov es,ax
xor eax,eax
cld
xor di,di
mov cx,65536/4
cld
rep stosd
pop es
ret

INIT_NUM ENDP

NUM_OUT PROC

cld
xor esi,esi
mov _count,esi
mov di,offset tmp_num0
mov cx,11
cmp cx,point
jbe no_adjust
mov cx,point
no_adjust:
sub point,cx
mov ds,bp
rep movsd
push cs
pop ds

push si
mov si,offset d_str1
call printf
pop si
no_lop:
cmp point,0
jle no_quit
mov cx,10
mov di,offset tmp_num
xor eax,eax
rep stosd

mov cx,10
mov di,offset tmp_num
cmp point,10
jae no1
mov cx,point
no1:
sub point,cx
add _count,50
mov ds,bp ;bp = result segment
rep movsd
push cs
pop ds

push si
mov si,offset d_str2
call printf
pop si
jmp short no_lop
no_quit:
ret

NUM_OUT ENDP

INCLUDE SCANF.ASM
INCLUDE PRINTF.ASM

CODE ENDS
END START