The DFG JIT will speculate that a value is an integer if the prediction logic tells us so. But this is dangerously unnecessary if the value will always be used as a double. For example, if o.f is predicted integer but is always used as o.f * 1.5, then there is no point to speculating that o.f is an integer because even if we do, we still have to convert it to a double.
Created attachment 107408 [details]
Landed in r95136.