Discriminated Union dispatch overhead with complex Active Patterns

F# utilizes internal integer tags for Discriminated Unions (DUs), typically resulting in O(1) dispatch time via jump tables. However, the introduction of Active Patterns allows for custom logic to be executed during the pattern matching process, shifting the dispatch mechanism from a simple tag check to a function call.

When integrating complex Active Patterns into high-frequency matching loops, there is a potential performance trade-off between the flexibility of the pattern and the raw speed of standard DU tag matching. It is unclear at what level of complexity an Active Pattern begins to significantly degrade the instruction cache efficiency or introduce measurable overhead compared to a standard match expression.

• Does the F# compiler apply any specific optimizations to simplify Active Patterns back into tag-based jumps when the logic is deterministic?
• What is the performance delta between a standard DU match and a Partial Active Pattern when processing large datasets?