(** ** Semantics of volatile stores *)

Inductive volatile_store_sem (chunk: memory_chunk) (ge: Senv.t):
              list val -> mem -> trace -> val -> mem -> Prop :=
  | volatile_store_sem_intro: forall b ofs m1 v t m2,
      volatile_store ge chunk m1 b ofs v t m2 ->
      volatile_store_sem chunk ge (Vptr b ofs :: v :: nil) m1 t Vundef m2.(** ** Semantics of volatile stores *)

Inductive volatile_store_sem (chunk: memory_chunk) (ge: Senv.t):
              list val -> mem -> trace -> val -> mem -> Prop :=
  | volatile_store_sem_intro: forall b ofs m1 v t m2,
      volatile_store ge chunk m1 b ofs v t m2 ->
      volatile_store_sem chunk ge (Vptr b ofs :: v :: nil) m1 t Vundef m2.

Lemma volatile_store_extends: forall ge chunk m1 b ofs v t m2 m1' v', volatile_store ge chunk m1 b ofs v t m2 -> Mem.extends m1 m1' -> Val.lessdef v v' -> exists m2', volatile_store ge chunk m1' b ofs v' t m2' /\ Mem.extends m2 m2' /\ Mem.unchanged_on (loc_out_of_bounds m1) m1' m2'.