buhao7-1.asm

.data val1 sword 0 val sword -276 .code main proc mov ax,val cwd mov bx,10 idiv bx

title 7-1
INCLUDE allyssa32.inc
.data
   array sdword 2 dup(?)
   str1 byte "Please input one 32-bit sign number :",0dh,0ah,0
   str2 byte "The result is : ",0
   align 4
   jia1gao sdword 0
   jia1 sdword 0
.code
main proc
    call clrscr
    mov esi,offset array
    mov ecx,lengthof array
    mov edx,offset str1
    push esi
putin:
    call writestring
    call readint
    mov [esi],eax
    add esi,4
loop putin
    pop esi   
    mov edx,offset str2
    call writestring  
    call mul32
    exit
main endp

mul32 proc
;-------------------
;receives :the offset address of array(store two 32-bit numbers)
;returns :nothing 
;-------------------
     mov ecx,31
     mov eax,[esi]
     cdq
     
     mov ebx,[esi+4]
     add eax,0
     jns sign
     add ebx,0
     jns fuzhi
     jmp neg1
sign:
     add ebx,0
     jns fuzhi
     js neg1
neg1:
     neg eax
     neg edx
     sub edx,1h
     neg ebx     
     ;call dumpregs
fuzhi:
     mov jia1,eax
     mov jia1gao,edx
shift:
     cmp ecx,0
     je quit
     add ebx,0 
     jns next
     push ecx
     push eax
     push edx
cl1:
     shl eax,1
     rcl edx,1
     ;call dumpregs
loop cl1
    ; call dumpregs
     add jia1,eax
     adc jia1gao,edx
     pop edx
     pop eax
     pop ecx
next: 
     shl ebx,1
     dec ecx
     ;call dumpregs 
     jmp shift 
quit:
     add ebx,0
     js bujian  
     sub jia1,eax
     sbb jia1gao,edx
bujian:
     mov esi,offset jia1gao
     mov ebx,4
     mov ecx,2
     call dumpmem
    
     ret
mul32 endp
   
end main