Sticky flags tend to be really annoying for a compiler to support for various reasons, but principally it makes every operation have a hidden dependency to shared global state that is almost never read. Note that IEEE 754 standardized support for sticky flags 40 years ago, but support for these sticky bits is still poor to nonexistent in most programming languages, and sticky bit stuff for floating-point operations is less problematic than integer operations because FP math is already far more black box in practice.