Morten Welinder wrote: > If you were to look up a serious math book like Abramowitz&Stegun1965 > you would see a definition like > > sin z = ((exp(iz)-exp(-iz))/2i [4.3.1]
Very true. However, the processor doesn't implement intrinsics for complex functions -- well, maybe some do, and I've never encountered them! As such, I was sticking to a discussion specific to reals. > And there is the answer to your question: if you just think of "sin" > as something > with angles and triangles, then sin(2^90) makes very little sense. But "sin" > occurs other places where there are no triangles in sight. That's certainly true; the use of sine and cosine depend on the application. I don't deny that many applications need to perform sin() on any double value; however there are also many applications where you *are* dealing with angles. I recently wrote a GPS application where using the intrinsics improved both accuracy and speed (the latter substantially), and using those intrinsics was only "unsafe" because -funsafe-math-optimizations includes other transformations. I am simply lobbying for the separation of hardware intrinsics from -funsafe-math-optimizations. ..Scott
