In x86 (intel notation) you can also: add rax, rbx rcr rax, 1 It explicitly uses the carry flag from the addition as the top bit of the right-rotated result.

In x86 (intel notation) you can also: add rax, rbx rcr rax, 1 It explicitly uses the carry flag from the addition as the top bit of the right-rotated result. Not super useful for anything other than averaging two uints but that's x86 for you. What I missed in my first pass was * Forgetting exactly which register was the low index and which was the high index * Underflow if array size was zero from setting the last index to (size - 1)