Definition ReadOnlyBlocks {F V} (ge: Genv.t F V) (b:block): bool :=
  match Genv.find_var_info ge b with
          None => false
        | Some gv => gvar_readonly gv && negb (gvar_volatile gv)
  end.

Lemma ReadOnlyBlocks_global {F V} (g:Genv.t F V) b: ReadOnlyBlocks g b = true -> isGlobalBlock g b = true.