Slide 12.5: Decision directives (cont.)
Slide 12.7: .WHILE directive
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.REPEAT Directive



The .REPEAT directive executes the loop body before testing the runtime condition following the .UNTIL directive. 

 .REPEAT
    statements
 .UNTIL  condition


The code on the right finds the remainder of a division by using the forumla: 
    i mod j
  = i - (i div j) × j
For example, 
  10 mod  3 =  1
 -10 mod -3 = -1
 -10 mod  3 = -1
  10 mod -3 =  1
 i mod j = i - (i div j) × j  
 INCLUDE Irvine32.inc
 .data
 prompt1   BYTE   "Dividend  = ", 0
 prompt2   BYTE   "Divisor   = ", 0
 prompt3   BYTE   "Remainder = ", 0
 dividend  SWORD  ?
 divisor   SWORD  ?

 .code
 main PROC
     call  Clrscr
     mov   edx, OFFSET prompt1
     call  WriteString
     call  ReadInt
     mov   dividend, ax

     mov   edx, OFFSET prompt2
     call  WriteString
     call  ReadInt
     mov   divisor, ax

     ; Check 0 for either operand.
     .IF (dividend==0 || divisor==0)
       mov  dividend, 0
       jmp  L1
     .ENDIF

     .REPEAT
       mov  bx, divisor
       .IF (dividend>0 && divisor>0)

    

     
            

            
     		
     

    
    
    


    

     		
    

   

       .ELSEIF (dividend<0 && divisor<0)
         sub  dividend, bx
         neg  bx
         mov  ax, dividend
         neg  ax

       .ELSEIF (dividend<0 && divisor>0)
         add  dividend, bx
         mov  ax, dividend
         neg  ax

       .ELSE
         add  dividend, bx
         neg  bx
         mov  ax, dividend
       .ENDIF
     .UNTIL (ax < bx)

 L1: mov    edx, OFFSET prompt3
     call   WriteString
     movsx  eax, dividend
     call   WriteInt
     exit
 main ENDP
 END main