Comment by obl

Weird that this treats uninitialized variables as unknown values. For example in ex3.c, the program

  int main(){
      int x;
      if (x <= 42){
              assert(x != 12345);
      }
  }

is of course UB in C, even though under a "uninitialized is random" model the program is valid and does not assert (as the model checker concludes).

(even in O1 clang gets rid of the whole function, including even the ret instruction, I'm surprised it does not at least leave an ud2 for an empty function to help debugging since it would not cost anything https://godbolt.org/z/eK8cz3EPe )