  We determine the phase diagram and pion spectrum for Wilson and twisted-mass
fermions in the presence of non-degeneracy between the up and down quark and
discretization errors, using Wilson and twisted-mass chiral perturbation
theory. We find that the CP-violating phase of the continuum theory (which
occurs for sufficiently large non-degeneracy) is continuously connected to the
Aoki-phase of the lattice theory with degenerate quarks. We show that
discretization effects can, in some cases, push simulations with physical
masses closer to either the CP-violating phase or another phase not present in
the continuum, so that at sufficiently large lattice spacings physical-point
simulations could lie in one of these phases.
