The code (actual instructions) that beats C++ in their example is being generated by their experimental "stream fusion" framework. And NOT by a generic Haskell compiler.

And now the question, do you really want to an unproven and unstable Haskell framework? While there are stable alternatives (lake Eigen, Theano, etc) available?

So no. Haskell (production ready Haskell) doesn't even come close.