Really good example. It also sucks that you have no way of knowing at build time whether autovectorisation succeeded. Even if you have it working initially it

Really good example. It also sucks that you have no way of knowing at build time whether autovectorisation succeeded. Even if you have it working initially it can silently break and you don't know where. So using clang, you're careful and you check the generated code and everything is great, then later it isn't and you have to go hunting to find out why.