How can the assembly be the same if one program leaks and the other doesn't? [duplicate]

I do apologize in advance if I am missing something glaringly obvious.

I have two versions of the same program. One intentionally leaks and one does not:

#include <iostream>int main() {    int* y = new int;    *y = 32;    printf("Y is: %i", *y);    delete y; //y doesn't leak    return 0;}

#include <iostream>int main() {    int* y = new int;    *y = 32;    printf("Y is: %i", *y);    //delete y; y leaks    return 0;}

Please see:https://gcc.godbolt.org/z/oPrsoKx1E (no optimization)

https://gcc.godbolt.org/z/nTq9K7jY7 (-O3 optimization)

What is interesting is that in the -O3 optimization the two programs produce identical assembly.

With no optimization the first program calls:

call    operator delete(void*, unsigned long)

But in the optimized code they have the exact same assembly. Clearly, the second program leaks while the first doesn't.