That’s my entire point. Compiler is free to make incorrect assumptions.
> It is also incorrect given the standard text.
According to C11 standard, section 3.4.3, the standard imposes no requirements on undefined behaviour.
In fact, in the rationale of the original spec., I remember reading that the C standard was expressly designed to be a minimal spec, and that just being compliant with the spec was insufficient for the resulting compiler to be fit for purpose.
And of course the original spec did specify a range of acceptable behaviors, and that language is, in fact, still in the standard. It was just made non-binding. However, it is still there, and pretending it is not seems disingenuous at best.
I agree, but that includes GCC and Clang. ¯\_(ツ)_/¯