Why doesn't GCC optimize out deletion of null pointers in C++?

Question

Consider a simple program:

int main() {
  int* ptr = nullptr;
  delete ptr;
}

With GCC (7.2), there is a call instruction regardi

Answer 1

It's a QOI issue. clang does indeed elide the test:

https://godbolt.org/g/nBSykD

main:                                   # @main
        xor     eax, eax
        ret