With thanks to Edgar, David and Frank, I'll reply generally rather than
individually.
From my observations in testing on AV Linux, I believe it comes down to a local
build
problem rather than anything I can solve via code. In the AV Linux testing, I
observed
that omitting -ffast-math in the build consistently resulted in incorrect
pitching.
I'm pretty much convinced that there's some subtle difference between distros
in the
environment or setup relating to libm.
cheers.
