(** Denotation functions for each of the assertions that can be produced by the typechecker **)

Definition denote_tc_iszero v : mpred :=
         match v with
         | Vint i => prop (is_true (Int.eq i Int.zero))
         | Vlong i => prop (is_true (Int64.eq i Int64.zero))
         | _ => FF
         end.Definition denote_tc_nonzero v : mpred :=
         match v with
         | Vint i => prop (i <> Int.zero)
         | Vlong i =>prop (i <> Int64.zero)
         | _ => FF end.Definition denote_tc_igt i v : mpred :=
     match v with
     | Vint i1 => prop (Int.unsigned i1 < Int.unsigned i)
     | _ => FF
     end.Definition denote_tc_lgt l v : mpred :=
     match v with
     | Vlong l1 => prop (Int64.unsigned l1 < Int64.unsigned l)
     | _ => FF
     end.Definition Zoffloat (f:float): option Z := (**r conversion to Z *)
  match f with
    | Fappli_IEEE.B754_finite s m (Zpos e) _ =>
       Some (Fcore_Zaux.cond_Zopp s (Zpos m) * Zpower_pos 2 e)
    | Fappli_IEEE.B754_finite s m 0 _ => Some (Fcore_Zaux.cond_Zopp s (Zpos m))
    | Fappli_IEEE.B754_finite s m (Zneg e) _ => Some (Fcore_Zaux.cond_Zopp s (Zpos m / Zpower_pos 2 e))
    | Fappli_IEEE.B754_zero _ => Some 0
    | _ => None
  end.(* copied from CompCert 2.3, because it's missing in CompCert 2.4 *)

Definition Zofsingle (f: float32): option Z := (**r conversion to Z *)
  match f with
    | Fappli_IEEE.B754_finite s m (Zpos e) _ =>
       Some (Fcore_Zaux.cond_Zopp s (Zpos m) * Zpower_pos 2 e)
    | Fappli_IEEE.B754_finite s m 0 _ => Some (Fcore_Zaux.cond_Zopp s (Zpos m))
    | Fappli_IEEE.B754_finite s m (Zneg e) _ => Some (Fcore_Zaux.cond_Zopp s (Zpos m / Zpower_pos 2 e))
    | Fappli_IEEE.B754_zero _ => Some 0
    | _ => None
  end.(* copied from CompCert 2.3, because it's missing in CompCert 2.4 *)


Definition denote_tc_Zge z v : mpred :=
          match v with
                     | Vfloat f => match Zoffloat f with
                                    | Some n => prop (z >= n)
                                    | None => FF
                                   end
                     | Vsingle f => match Zofsingle f with
                                    | Some n => prop (z >= n)
                                    | None => FF
                                   end
                     | _ => FF
                  end.Definition denote_tc_Zle z v : mpred :=
          match v with
                     | Vfloat f => match Zoffloat f with
                                    | Some n => prop (z <= n)
                                    | None => FF
                                   end
                     | Vsingle f => match Zofsingle f with
                                    | Some n => prop (z <= n)
                                    | None => FF
                                   end
                     | _ => FF
                  end.Definition sameblock v1 v2 : bool :=
         match v1, v2 with
          | Vptr b1 _, Vptr b2 _ => peq b1 b2
          | _, _ => false
         end.Definition denote_tc_samebase v1 v2 : mpred :=
       prop (is_true (sameblock v1 v2)).(** Case for division of int min by -1, which would cause overflow **)
Definition denote_tc_nodivover v1 v2 : mpred :=
match v1, v2 with
          | Vint n1, Vint n2 => prop (~(n1 = Int.repr Int.min_signed /\ n2 = Int.mone))
          | Vlong n1, Vlong n2 => prop (~(n1 = Int64.repr Int64.min_signed /\ n2 = Int64.mone))
          | Vint n1, Vlong n2 => TT
          | Vlong n1, Vint n2 => prop (~ (n1 = Int64.repr Int64.min_signed  /\ n2 = Int.mone))
          | _ , _ => FF
        end.Definition denote_tc_nosignedover (op: Z->Z->Z) v1 v2 : mpred :=
 match v1,v2 with
 | Vint n1, Vint n2 => 
   prop (Int.min_signed <= op (Int.signed n1) (Int.signed n2) <= Int.max_signed)
 | Vlong n1, Vlong n2 =>
   prop (Int64.min_signed <= op (Int64.signed n1) (Int64.signed n2) <= Int64.max_signed)
 | Vint n1, Vlong n2 =>
   prop (Int64.min_signed <= op (Int.signed n1) (Int64.signed n2) <= Int64.max_signed)
 | Vlong n1, Vint n2 =>
   prop (Int64.min_signed <= op (Int64.signed n1) (Int.signed n2) <= Int64.max_signed)
 | _, _ => FF
 end.Definition denote_tc_initialized id ty rho : mpred :=
    prop (exists v, Map.get (te_of rho) id = Some v
               /\ tc_val ty v).Definition denote_tc_isptr v : mpred :=
  prop (isptr v).Definition denote_tc_isint v : mpred :=
  prop (is_int I32 Signed v).Definition denote_tc_islong v : mpred :=
  prop (is_long v).Definition test_eq_ptrs v1 v2 : mpred :=
  if sameblock v1 v2
  then (andp (weak_valid_pointer v1) (weak_valid_pointer v2))
  else (andp (valid_pointer v1) (valid_pointer v2)).Definition test_order_ptrs v1 v2 : mpred :=
  if sameblock v1 v2
  then (andp (weak_valid_pointer v1) (weak_valid_pointer v2))
  else FF.Definition denote_tc_test_eq v1 v2 : mpred :=
 match v1, v2 with
 | Vint i, Vint j => 
     if Archi.ptr64 then FF else andp (prop (i = Int.zero)) (prop (j = Int.zero))
 | Vlong i, Vlong j => 
     if Archi.ptr64 then andp (prop (i = Int64.zero)) (prop (j = Int64.zero)) else FF
 | Vint i, Vptr _ _ =>
      if Archi.ptr64 then FF else andp (prop (i = Int.zero)) (weak_valid_pointer v2)
 | Vlong i, Vptr _ _ =>
      if Archi.ptr64 then andp (prop (i = Int64.zero)) (weak_valid_pointer v2) else FF
 | Vptr _ _, Vint i =>
      if Archi.ptr64 then FF else andp (prop (i = Int.zero)) (weak_valid_pointer v1)
 | Vptr _ _, Vlong i =>
      if Archi.ptr64 then andp (prop (i = Int64.zero)) (weak_valid_pointer v1) else FF
 | Vptr _ _, Vptr _ _ =>
      test_eq_ptrs v1 v2
 | _, _ => FF
 end.Definition denote_tc_test_order v1 v2 : mpred :=
 match v1, v2 with
 | Vint i, Vint j => if Archi.ptr64 then FF else andp (prop (i = Int.zero)) (prop (j = Int.zero))
 | Vlong i, Vlong j => if Archi.ptr64 then andp (prop (i = Int64.zero)) (prop (j = Int64.zero)) else FF
 | Vptr _ _, Vptr _ _ =>
      test_order_ptrs v1 v2
 | _, _ => FF
 end.Definition typecheck_error (e: tc_error) : Prop := False.

Lemma is_true_e: forall b, is_true b -> b=true.