[linspace]

I think the problem is libraries implicitly affecting code outside the library. This time has been related to optimization of floating point operations, next time it will be other thing. Why bother having lexically scoped languages if the real behavior is dinamical? Debugging this kind of error is very hard

[titzer]

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.