[Octave-bug-tracker] [bug #54302] power operator: 0.^0 results in NaN in some case

[Dan Sebald]

Follow-up Comment #6, bug #54302 (project octave):

I was just thinking back, regarding the 


 xpow (const Complex& a, double b)
 {
-  Complex result;
-
-  if (xisint (b))
-    result = std::pow (a, static_cast<int> (b));


that I removed in the patch, is it possibly the case that at one time these
routines used


    result = pow (a, static_cast<int> (b));


and that was supposed to find the version of pow() I listed in the previous
post, originating from oct-inttypes.cc?  That integer version might be
slightly more accurate than std::pow(), but possibly a little slower...not
drastically slow because it does use a fairly fast reduction by squaring the
running product and bit-shifting b.  I would imagine that std::pow() is using
logarithms or something similar to turn power into multiplication.

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