In SX Microcontrollers, SX/B Compiler and SX-Key Tool, Zoot wrote:

Peter -- this libs are fairly similar to my own math libs, although I handle banking for tmp variables a little differently. In any case, one thing I noticed is that you are not accounting for rounding, something I do in my own functions, e.g. (simplified example, my actual libs have more ASM)....

[code]

FUNC MATH_DIV
   IF __PARAMCNT < 4 THEN
      __PARAM4 = 0
      IF __PARAMCNT < 3 THEN
         __PARAM3 = __PARAM2
         __PARAM2 = 0
      ENDIF
   ENDIF
   tmpW1 = __WPARAM12
   tmpW2 = __WPARAM34
   \CLC                              ' add 1/2 of divisor for cleaner rounding
   \RR __PARAM4
   \RR __PARAM3
   tmpW1 = tmpW1 + __WPARAM34
   tmpW1 = tmpW1 / tmpW2
   RETURN tmpW1
   ENDFUNC
[code]

For my mid-multiply (*/) function I do something similar, but obviously #128 is added to the first word since the divisor is always 256.

In any case, I've found that this gives me much closer integer results, esp. when numbers may be manipulated a bit (a good example would be encoder odometry and trig).

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