Performargs

Performargs is a term used in software engineering to describe techniques and patterns for preparing function arguments prior to invocation in order to improve performance and reliability. The concept focuses on reducing runtime overhead by precomputing argument representations, validating inputs at the call site, and avoiding unnecessary allocations. In practice, performargs intersects with calling conventions, inlining decisions, and wrapper design to minimize dispatch and boxing costs.

Core elements commonly associated with performargs include early validation and defaulting, type conversion or coercion, packing arguments into a single payload (such as a tuple, struct, or fixed-size array), and using preallocated buffers or stack-allocated storage to avoid heap allocations. In some contexts, generate-time or compile-time wrappers are used to match specific function signatures.

Contexts where performargs is discussed include high-performance libraries, game engines, real-time systems, and languages that emphasize performance and type safety. It is often contrasted with dynamic argument handling, where validation and conversion occur at call time.

Criticism notes that performargs can increase code complexity and reduce readability, and that many languages provide built-in mechanisms (named or optional parameters, defaults, and type annotations) that can achieve similar goals with less manual work. Some approaches prefer abstracting argument handling behind helper utilities or using language features such as variadic templates, currying, or partial application.

See also function arguments, argument parsing, calling convention, inlining, and performance optimization.