Learn To Code: 16bit Binary Multiply and Division operations

[kevin]

   Learn To Code:  16bit Binary Multiply and Division operations

   Ever wonder how your computers performs Multiply or even Division in a fixed time ?    

   

     OPerators Used:  + Addition  - Subtraction  << Shit Left/Up  >> Shift Right/Down  and ^ power

PlayBASIC Code: [Select]

; PROJECT : 16bit Multiply and Divide Functions
; AUTHOR  : Kevin Picone  - PlayBASIC Tutor
; CREATED : 20/03/2022
; EDITED  : 20/03/2022
; ---------------------------------------------------------------------

      //  Run Code in DEBUG MODE (f7 from IDE)


      MaxTests=100

      Test_Mults(MaxTests)

      Test_Division(MaxTests)
   
      Sync
      waitkey
      


Function Test_Mults(MaxTests)
   
   s$=make$("-",100)
   #print s$
   #print "Multiply Test"+make$("-",60)
   #print s$
   a=100
   for lp= 1 to MaxTests
         a=rnd($ffff)
         b=rnd($ffff)
         
         result1=Mult(a,b)
         result2=a*b
         
         Status=Result1<>Result2
         Failed+=Status
         #print "Mult:("+str$(a)+","+str$(b)+")="+str$(Result1)+"   A*B="+str$(result2)+" Status="+str$(Status)
   next
   #print ""
   #print "Result="+Str$(Failed)+" Fails"
   #print s$
   #print ""   
   #print ""   
   
Endfunction




Function Test_Division(MaxTests)
   
   s$=make$("-",100)
   #print s$
   #print "Division Test"+make$("-",60)
   #print s$
   a=100
   for lp= 1 to MaxTests
         a=rnd($ffff)
         b=rnd($ffff)
         swapiflower a,b
         
         result1,Remainder1 =Div(a,b)
         result2            =a/b
         Remainder2 = a-(B*result2)         
         Status=Result1<>Result2
         Failed+=Status
         #print "Div:("+str$(a)+","+str$(b)+")="+str$(Result1)+" Remainder:"+str$(Remainder1)+"   A/B="+str$(result2)+" Remainder:"+str$(Remainder2)+" Status="+str$(Status)
   next
   #print ""
   #print "Result="+Str$(Failed)+" Fails"
   #print s$
   #print ""   
   #print ""   
   
Endfunction



/*   -------------------------------------------------------------
   ------------>> Unsigned Integer 16bit Multiply <<------------
   -------------------------------------------------------------

      This function performs a fixed time unsigned 16bit multiply
      between a pair of 16 bit integers.
      
  ------------------------------------------------------------- */


Function Mult(A,B)
   
   if B
      For lp =0 to 15
         if B and 1
            Result += A << lp      
         endif
         B=B >> 1
      next
   endif
   
EndFunction Result


/*   -------------------------------------------------------------
   ------------>> Unsigned Integer 16bit Divider <<------------
   -------------------------------------------------------------

      This function performs a fixed time unsigned 16bit division
      with remainder between a pair of 16bit integers
      
  ------------------------------------------------------------- */


Function Div(A,B)
   remainder=A   
   if B
         For lp =15 to 0 step -1
            if (B<<lp)<=A
               A-=(B<<lp)
               Result+=2 ^ lp
            endif
         next
         remainder=A            
   endif
   
EndFunction Result,Remainder