Wow, I didn't know this. It's such a great feature, they really should advertise it more.
(Examining assembler output shows that a naïve implementation of fact() also gets the autovectorization treatment as well as a fair bit of loop unrolling. Very impressive.)
(Examining assembler output shows that a naïve implementation of fact() also gets the autovectorization treatment as well as a fair bit of loop unrolling. Very impressive.)