Remark int64_eq_xor:
forall p q, Int64.eq p q = Int64.eq (Int64.xor p q) Int64.zero.

Theorem eval_cmplu:
forall c le a x b y v,
eval_expr ge sp e m le a x ->
eval_expr ge sp e m le b y ->
Val.cmplu (Mem.valid_pointer m) c x y = Some v ->
Archi.ptr64 = false ->
eval_expr ge sp e m le (cmplu c a b) v.