Can you come up with a vectorization optimizer pass that could do what the OP did in the article? This isn't a compiler bug or a shortcoming, it's a non-trivia

Can you come up with a vectorization optimizer pass that could do what the OP did in the article? This isn't a compiler bug or a shortcoming, it's a non-trivial optimization. Especially given the aliasing between the input and output (ie. it's an in-place algorithm) this is going to be a very difficult optimization.