Thanks. On godbolt, I see clang do it at -O3. But gcc still has a loop, where the body has add but no mul, although I don't fully understand the body. Where

Thanks. On godbolt, I see clang do it at -O3. But gcc still has a loop, where the body has add but no mul, although I don't fully understand the body. Where do you see it in gcc? https://godbolt.org/z/sP194Y https://godbolt.org/z/sP194Y