Greg Stark <gsstark@mit.edu> writes:
> If there's a performance advantage then we could add a configure test
> and define the macro to call hypot(). You said it existed before C99
> though, how widespread was it? If it's in all the platforms we support
> it might be reasonable to just go with it.
For one data point, I see hypot() in HPUX 10.20, released circa 1996.
I suspect we would want a configure test and a substitute function
anyway. Personally I wouldn't have a problem with the substitute being
the naive sqrt(x*x+y*y), particularly if it's replacing existing code
that overflows in the same places.
regards, tom lane
