(** ** 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_readonly:
forall ge chunk1 m1 b1 ofs1 v t m2,
volatile_store ge chunk1 m1 b1 ofs1 v t m2 ->
Mem.unchanged_on (loc_not_writable m1) m1 m2.