On Tue, May 7, 2019 at 11:08 AM tedheadster <tedheadster@xxxxxxxxx> wrote: > > On Tue, May 7, 2019 at 10:55 AM Jeffrey Walton <noloader@xxxxxxxxx> wrote: > > > > As far as I know the instruction is only defined for Intel, AMD and > > Hyogen cpus. See, for example, > > https://github.com/weidai11/cryptopp/blob/master/cpu.cpp#L380. > > > > Jeff, > I think you missed my point. The rdrand instruction is _not_ > supported on this old hardware at all. The code should detect that and > avoid using it. Ack. My guess is, the Winchip manual says something like the bits are undefined and you should not be relying on them. The test for Intel, AMD or Hyogen should keep you out of the code path on that particular cpu. Jeff
