StrictMath has more features than Math. It's more precise ---> slower.
Long has more features than int. It has a larger range of values ---> slower.
Okay, not the best comparison, but that´s not really the point. Math is supposed to be optimized with native code, while StrictMath ensures that you get the exact same result on every computer that runs it. From just that we can easily draw the conclusion that Math >= StrictMath in performance. They may be equally fast if the native Math version produces the same value as the StrictMath version in which case both should use the native version. However, if StrictMath is faster it means that it´s more precise (since it´s not the same function as the Math one if it´s slower) AND faster it should be treated as a bug in the VM. Math should never be slower than StrictMath.
Even the long/int comparison holds here. Future/current (
) CPUs might be able to do 64-bit math in a single cycle, but a long should NEVER be faster than an int.