It's not necessarily something you'd use today(?), but Duff's Device has always struck me as particularly beautiful: send(to, from, count) register sho

It's not necessarily something you'd use today(?), but Duff's Device has always struck me as particularly beautiful: send(to, from, count) register short *to, *from; register count; { register n = (count + 7) / 8; switch (count % 8) { case 0: do { *to = *from++; case 7: *to = *from++; case 6: *to = *from++; case 5: *to = *from++; case 4: *to = *from++; case 3: *to = *from++; case 2: *to = *from++; case 1: *to = *from++; } while (--n > 0); } } > In the C programming language, Duff's device is a way of manually implementing loop unrolling by interleaving two syntactic constructs of C: the do-while loop and a switch statement. Its discovery is credited to Tom Duff in November 1983, when Duff was working for Lucasfilm and used it to speed up a real-time animation program. https://en.wikipedia.org/wiki/Duff%27s_device https://en.wikipedia.org/wiki/Duff%27s_device