This feels a lot like profile-guided optimization - it can't be much of a step from PGO observing that a branch is never taken during profiling and so marking t

This feels a lot like profile-guided optimization - it can't be much of a step from PGO observing that a branch is never taken during profiling and so marking the not-taken path cold, to eliminating the not-taken path (and the branch test) entirely. I wonder whether PGO was available in open-source compilers back in 2004?