Agreed. Side-effects to global state is generally bad. It would have been not as bad to introduce the FTZ mode in a way that wasn't global state, but alas, the

Agreed. Side-effects to global state is generally bad. It would have been not as bad to introduce the FTZ mode in a way that wasn't global state, but alas, the performance mode itself was the original sin. There is apparently zero overhead for subnormals on PPC and very little on arm. It's always been Intel pushing this crap because of their FPU designs' shortcomings.