-O0 program is useless and should be written with any other language. The whole point of C is to use compiler with optimizations. I'm not against optimizations. I'm against optimizations that perform things unexpected by the programmer. Dead code removal is unexpected by the programmer, because programmer does not write dead code.

Well you can't have your cake and eat it too ;)

> Dead code removal is unexpected by the programmer, because programmer does not write dead code.

Of course it is expected, because the optimizations leading to dead code are fundamental for the performance you get out of a release-mode binary (and that's also true for languages with less UB like Rust btw).

When you have a function:

    static int add(int a, int b) {
        return a + b;
    }

    int c = add(2, 3);