Wait a minute, I've seen it stated many times that a primary reason FORTRAN can be better optimised than C is that it doesn't allow aliasing memory as easily as C does (what that means, maybe you can say), and that's why 'restrict' was added to C. On the other hand, C's "strict aliasing rule" allows compilers to assume that pointers of different types don't alias the same memory, which allows optimisations.