[Ival] The small_cardinal limit is only set once in int_set.

Int_val uses the limit provided by int_set.get_small_cardinal to create
sets or intervals.

src/kernel_services/abstract_interp/int_set.ml

@@ -25,6 +25,7 @@ open Bottom.Type
 
 (* Make sure all this is synchronized with the default value of -ilevel *)
 let small_cardinal = ref 8
+let get_small_cardinal () = !small_cardinal
 let set_small_cardinal i = small_cardinal := i
 
 let debug_cardinal = false

src/kernel_services/abstract_interp/int_set.mli

@@ -87,5 +87,7 @@ val subdivide: t -> t * t
 
 (**/**)
 
+val get_small_cardinal: unit -> int
+
 (* This is used by the Value plugin. Do not use. *)
 val set_small_cardinal: int -> unit

src/kernel_services/abstract_interp/int_val.ml

@@ -23,29 +23,12 @@
 open Abstract_interp
 open Bottom.Type
 
-(* Make sure all this is synchronized with the default value of -ilevel *)
-let small_cardinal = ref 8
-let small_cardinal_Int = ref (Int.of_int !small_cardinal)
-let small_cardinal_log = ref 3
-
-let set_small_cardinal i =
-  assert (2 <= i && i <= 1024);
-  let rec log j p =
-    if i <= p then j
-    else log (j+1) (2*p)
-  in
-  small_cardinal := i;
-  small_cardinal_Int := Int.of_int i;
-  small_cardinal_log := log 1 2;
-  (* TODO: share this code with Int_set *)
-  Int_set.set_small_cardinal i
-
-let get_small_cardinal () = !small_cardinal
+let small_cardinal = Int_set.get_small_cardinal
+let small_cardinal_Int () = Int.of_int (small_cardinal ())
 
 let emitter = Lattice_messages.register "Int_val"
 let log_imprecision s = Lattice_messages.emit_imprecision emitter s
 
-
 module Widen_Hints = Datatype.Integer.Set
 type size_widen_hint = Integer.t
 type generic_widen_hint = Widen_Hints.t
@@ -144,7 +127,7 @@ let make ~min ~max ~rem ~modu =
     then inject_singleton mn
     else
       let l = Int.succ (Int.e_div (Int.sub mx mn) modu) in
-      if Int.le l !small_cardinal_Int
+      if Int.le l (small_cardinal_Int ())
       then
         let l = Int.to_int l in
         let s = Array.make l Int.zero in
@@ -190,7 +173,7 @@ let inject_itv i =
   match Int_interval.cardinal i with
   | None -> Itv i
   | Some card ->
-    if Int.le card !small_cardinal_Int
+    if Int.le card (small_cardinal_Int ())
     then
       let min, max, rem, modu = Int_interval.min_max_rem_modu i in
       make ~min ~max ~rem ~modu
@@ -365,18 +348,19 @@ let diff_if_one value rem =
         | _, Some mx when Int.equal v mx ->
           check_make_or_bottom ~min ~max:(Some (Int.sub mx modu)) ~rem ~modu
         | Some mn, Some mx when
-            Int.equal (Int.sub mx mn) (Int.mul modu !small_cardinal_Int)
+            Int.equal (Int.sub mx mn) (Int.mul modu (small_cardinal_Int ()))
             && Int_interval.mem v i ->
           let r = ref mn in
+          let small_cardinal = small_cardinal () in
           let array =
-            Array.init !small_cardinal
+            Array.init small_cardinal
               (fun _ ->
                  let c = !r in
                  let corrected_c = if Int.equal c v then Int.add c modu else c in
                  r := Int.add corrected_c modu;
                  corrected_c)
           in
-          `Value (Set (Int_set.inject_array array !small_cardinal))
+          `Value (Set (Int_set.inject_array array small_cardinal))
         | _, _ -> `Value value
     end
   | _ -> `Value value
@@ -628,7 +612,7 @@ let create_all_values ~signed ~size =
   in
   let min = Some min
   and max = Some max in
-  if size <= !small_cardinal_log
+  if size < Z.numbits (small_cardinal_Int ())
   then make ~min ~max ~rem:Int.zero ~modu:Int.one
   else Itv (Int_interval.inject_range min max)
 
@@ -977,7 +961,7 @@ struct
     let acc = ref (set_bit Sign [] (r, v1, v2)) in
     for i = size - 1 downto Z.numbits modu - 1 do
       acc := List.fold_left (set_bit (Bit i)) [] !acc;
-      if List.length !acc > !small_cardinal then raise Do_not_fit_small_sets
+      if List.length !acc > small_cardinal () then raise Do_not_fit_small_sets
     done;
     let o = List.fold_left (fun o (r,_,_) -> O.add r o) O.empty !acc in
     let cardinal = O.cardinal o in

src/kernel_services/abstract_interp/int_val.mli

@@ -116,7 +116,4 @@ val overlaps: partial:bool -> size:Integer.t -> t -> t -> bool
 
 val fold_int : (Integer.t -> 'a -> 'a) -> t -> 'a -> 'a
 
-val get_small_cardinal: unit -> int
-val set_small_cardinal: int -> unit
-
 val rehash: t -> t

src/kernel_services/abstract_interp/ival.ml

@@ -22,9 +22,6 @@
 
 open Abstract_interp
 
-let set_small_cardinal i = Int_val.set_small_cardinal i
-let get_small_cardinal = Int_val.get_small_cardinal
-
 let emitter = Lattice_messages.register "Ival"
 let log_imprecision s = Lattice_messages.emit_imprecision emitter s
 

src/kernel_services/abstract_interp/ival.mli

@@ -305,14 +305,8 @@ val complement_int_under: size:int -> signed:bool -> t -> t Bottom.or_bottom
 
 val pretty_debug : Format.formatter -> t -> unit
 
-val get_small_cardinal: unit -> int
-(** Value of option -ilevel *)
-
 (**/**)
 
-(* This is used by the Value plugin. Do not use. *)
-val set_small_cardinal: int -> unit
-
 val rehash: t -> t (* Low-level operation for demarshalling *)
 (**/**)
 

src/plugins/value/domains/cvalue/builtins_memory.ml

@@ -533,7 +533,7 @@ let memset_typ_offsm_int full_typ i =
 let memset_typ_offsm typ v =
   try
     let i = V.project_ival v in
-    ignore (Ival.cardinal_less_than i (Ival.get_small_cardinal ()));
+    ignore (Ival.cardinal_less_than i (Int_set.get_small_cardinal ()));
     let aux_i i offsm =
       let offsm_i = memset_typ_offsm_int typ i in
       match offsm with

src/plugins/value/domains/cvalue/builtins_string.ml

@@ -259,7 +259,7 @@ let search_offsm kind ~validity ~offset offsetmap =
 
 (* Generic function to fold a search according to a small set of integers. *)
 let search_by_folding ival search =
-  if Ival.cardinal_is_less_than ival (Ival.get_small_cardinal ())
+  if Ival.cardinal_is_less_than ival (Int_set.get_small_cardinal ())
   then Ival.fold_enum (fun ival acc -> join acc (search ival)) ival empty
   else search ival
 

src/plugins/value/domains/cvalue/cvalue_domain.ml

@@ -119,7 +119,7 @@ module Model = struct
 
   let backward_location state _lval typ precise_loc value =
     let size = Precise_locs.loc_size precise_loc in
-    let upto = succ (Ival.get_small_cardinal()) in
+    let upto = succ (Int_set.get_small_cardinal()) in
     let loc = Precise_locs.imprecise_location precise_loc in
     let eval_one_loc single_loc =
       let v = Cvalue.Model.find state single_loc in

src/plugins/value/engine/subdivided_evaluation.ml

@@ -898,7 +898,7 @@ module Make
           then Bottom.join Value.join (`Value subvalue) acc else acc
         in
         let cvalue = get_cval v in
-        let upto = succ (Ival.get_small_cardinal ()) in
+        let upto = succ (Int_set.get_small_cardinal ()) in
         fold_enumerate upto process cvalue `Bottom >>-: fun value ->
         if Value.equal v value
         then valuation

src/plugins/value/value_parameters.ml

@@ -947,7 +947,7 @@ module ILevel =
     end)
 let () = add_precision_dep ILevel.parameter
 let () = ILevel.add_aliases ["-val-ilevel"]
-let () = ILevel.add_update_hook (fun _ i -> Ival.set_small_cardinal i)
+let () = ILevel.add_update_hook (fun _ i -> Int_set.set_small_cardinal i)
 let () = ILevel.set_range 4 256
 
 let () = Parameter_customize.set_group precision_tuning