+1 on the __attribute__((cold)). Compilers so aggressively optimize based on their heuristics that you spend more time telling them that an apparent optimizatio

+1 on the __attribute__((cold)). Compilers so aggressively optimize based on their heuristics that you spend more time telling them that an apparent optimization opportunity is not actually an optimization. When writing ultra-robust code that has to survive every vaguely plausible contingency in a graceful way, the code is littered with code paths that only exist for astronomically improbable situations. The branch predictor can figure this out but the compiler frequently cannot without explicit instructions to not pollute the i-cache.