From uint64_t GetRdRand() noexcept :

In the case of ten RdRand failures in a row: wouldn't r1 be read uninitialized on L150? (If so, then the same goes for the __i386__ case a couple of lines above.)

It should be noted that the odds of ten RdRand failures in a row are astronomically small, so I don't think this is urgent at all. Would be nice to rule out the theoretical possibility though (if such a possibility exists).

Friendly ping @sipa :)