Maths: shift4Right

       Name: shift4Right                                             [Show more]
       Type: Variable
   Category: Maths
    Summary: Lookup table for shifting a byte four places to the right, to
             extract the high nibble
  Deep dive: Times tables and nibble arithmetic
    Context: See this variable in context in the source code
 References: This variable is used as follows:
             * DivideScaled uses shift4Right
             * Multiply4x16 uses shift4Right
             * Multiply8x8 uses shift4Right
             * ScaleUp uses shift4Right
             * SetObjPointCoords (Part 1 of 2) uses shift4Right


 In the table below, shift4Right,X contains the high byte of X * 16. So if X is
 %XXXXxxxx, shift4Right,X contains %0000XXXX.


.shift4Right

 FOR I%, 0, 255

  EQUB HI(I% * 16)

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