Regardless of optimization level, the effects of undefined behavior are not optional. Adjusting the optimization level of the compiler does not adjust the seman

Regardless of optimization level, the effects of undefined behavior are not optional. Adjusting the optimization level of the compiler does not adjust the semantics of the language as far as the compiler is worried. If you're worried about an optimization changing the functionality of your program, you really should be adjusting the feature/dialect settings (for clang/GCC this means the -f flags, not the -O flags)