Matt Godbolt's blog
15 hours ago
- Inlining is crucial for optimization but can cause code bloat; partial inlining offers a middle ground.
- Function outlining extracts cold paths into separate functions, leaving a thin wrapper for the hot path.
- Partial inlining inlines only the wrapper, keeping calls to the outlined cold path, reducing duplication.
- This allows the compiler to gain performance benefits of inlining for simple checks without duplicating expensive computations.
- The original function remains intact for external callers, ensuring correctness.
- Compiler heuristics guide partial inlining decisions, but developers should verify their hot code paths.
- Different compilers (e.g., GCC and Clang) may apply partial inlining differently.