Polymorphic functions force V8 to generate slow generic code
warningperformanceUpdated Feb 8, 2026(via Exa)
Technologies:
How to detect:
Functions receiving arguments of different types at the same call site become polymorphic or megamorphic, forcing V8 to generate slower generic code instead of optimized monomorphic fast paths.
Recommended action:
Create separate functions for each type instead of one function handling multiple types. Each monomorphic function gets independently optimized by V8.