Maths (Arithmetic): MULTU

       Name: MULTU                                                   [Show more]
       Type: Subroutine
   Category: Maths (Arithmetic)
    Summary: Calculate (A P) = P * Q
    Context: See this subroutine in context in the source code
 References: This subroutine is called as follows:
             * GCASH calls MULTU
             * PLS3 calls MULTU
             * TT24 calls MULTU


 Do the following multiplication of unsigned 8-bit numbers:

   (A P) = P * Q


.MULTU

 LDX Q                  \ Set X = Q

 BEQ MU1                \ If X = Q = 0, jump to MU1 to copy X into P and A,
                        \ clear the C flag and return from the subroutine using
                        \ a tail call

                        \ Otherwise fall through into MU11 to set (A P) = P * X