3 ms·

> I think the optimizer recognizes modulo 2 and converts it to bitwise AND. You don't have to guess, you could turn or O3 or look at the disassembly.

• lcampbell 2y ago
  Interestingly, not only do both versions emit the same assembly, but clang both autovectorizes and unrolls the loop: https://godbolt.org/z/qxsKWfz9s https://godbolt.org/z/qxsKWfz9s
• deleted 2y ago
  [deleted]
• caspper69 2y ago
  gcc does it even when it's not optimizing