(limited connectivity for me)
For some perspective, recently gcc and clang have introduced
optimizations based on undefined behavior in C/C++. The undefined
behavior has been interpreted by modern optimizers as "these cases will
never happen". This has wound up breaking a significant amount of
existing code. There have been a number of articles about these, with
detailed explanations about how they come about and the new, more
correct, way to write code.
The emerging consensus is that the code breakage is worth it for the
performance gains. That said, I do hear what people are saying about
potential code breakage and agree that we need to address this properly.
