Handling out of order execution

Question

I recently stumbled upon this Wikipedia article. From my experience with multi-threading I am aware of the multitude of issues caused by the program being able to switch threads

Answer 1

The compiler does not generate out of execution errors, it optimizes and reorders however it likes as long as what it produces yields the result your source code says it should.

But in dealing with multihreading, this can indeed blow up, though that generally has little to do with how the compiler has reordered your code (though it could make it worse in otherwise optimistic cases.

Dealing with threads operating on the same data, you need to be very, very careful and make sure your data is properly guarded with the appropriate guarding (semaphores/mutexes/atomic operations and similar)