[JonChesterfield]

ISO C comes with a list of constructs that the language is entitled to silently miscompile. Varying from "those bytes can't be an integer, I'll delete that function for you" through "signed integers can't overflow, so that overflow check you wrote must return false, so I'll delete it for you".

This makes simple application code slightly faster. That's kind of a reasonable domain for C++ but on dubious ground for C. Where C is superb is talking to hardware and language implementation, exactly the areas the ISO group has chosen to cripple the language for.

Thankfully compilers know about this and provide fno-strict-aliasing et al. Maybe there should be a std= style flag to change to the language subset that doesn't actively try to miscompile your program chasing benchmark numbers.