Merge pull request #590 from cryspen/lf-avx2-serialize-deserialize-4

F*: avx2: `{de,}serialize{1,4,10,12}`

fstar-helpers/fstar-bitvec/BitVec.Equality.fst

@@ -33,7 +33,16 @@ let bv_equality' #n (bv1 bv2: bit_vec n)
 
 
 let bv_equality #n (bv1 bv2: bit_vec n) = bv_equality' bv1 bv2
-
+
+let bv_equality_elim #n (bv1 bv2: bit_vec n)
+  : Lemma (requires bv_equality bv1 bv2)
+          (ensures  bv1 == bv2)
+  = ()
+let bv_equality_intro #n (bv1 bv2: bit_vec n)
+  : Lemma (requires bv1 == bv2)
+          (ensures  bv_equality bv1 bv2)
+  = ()
+
 let rewrite n (bv1: bit_vec n)
   : Lemma (bv_equality #n bv1 bv1 == true)
   = ()

fstar-helpers/fstar-bitvec/BitVec.Equality.fsti

@@ -6,4 +6,12 @@ open FStar.Mul
 open FStar.FunctionalExtensionality
 
 val bv_equality #n (bv1 bv2: bit_vec n): bool
+val bv_equality_elim #n (bv1 bv2: bit_vec n)
+  : Lemma (requires bv_equality bv1 bv2)
+          (ensures  bv1 == bv2)
+val bv_equality_intro #n (bv1 bv2: bit_vec n)
+  : Lemma (requires bv1 == bv2)
+          (ensures  bv_equality bv1 bv2)
 val rewrite n (bv1: bit_vec n): Lemma (bv_equality #n bv1 bv1 == true)
+
+

fstar-helpers/fstar-bitvec/BitVec.Intrinsics.Constants.fst

@@ -0,0 +1,264 @@
+module BitVec.Intrinsics.Constants
+
+open Core
+open Rust_primitives
+open FStar.Mul
+open FStar.FunctionalExtensionality
+open BitVec.Utils
+open BitVec.Equality
+
+let mm256_set_epi16 (x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12 x13 x14 x15: i16)
+  : bit_vec 256
+  = mk_bv (fun i ->
+      let offset = i % 16 in
+      match i / 16 with
+      |  0 -> get_bit x15 (sz offset)
+      |  1 -> get_bit x14 (sz offset)
+      |  2 -> get_bit x13 (sz offset)
+      |  3 -> get_bit x12 (sz offset)
+      |  4 -> get_bit x11 (sz offset)
+      |  5 -> get_bit x10 (sz offset)
+      |  6 -> get_bit x9 (sz offset)
+      |  7 -> get_bit x8 (sz offset)
+      |  8 -> get_bit x7 (sz offset)
+      |  9 -> get_bit x6 (sz offset)
+      | 10 -> get_bit x5 (sz offset)
+      | 11 -> get_bit x4 (sz offset)
+      | 12 -> get_bit x3 (sz offset)
+      | 13 -> get_bit x2 (sz offset)
+      | 14 -> get_bit x1 (sz offset)
+      | 15 -> get_bit x0 (sz offset)
+    )
+
+let madd_rhs (n: nat {n < 16}) = 
+  mm256_set_epi16 
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s 
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s 
+    (1s <<! Int32.int_to_t n <: i16)
+    1s 
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s 
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s 
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s
+
+open FStar.Tactics.V2
+
+let _ = namedv_view
+
+irreducible let stupid (x: 'a): bit_vec 256 -> bit_vec 256 = admit ()
+
+open Tactics.Utils
+
+open FStar.Tactics
+
+(** Unifies `t` with `fn x1 ... xN`, where `x1` and `xN` are
+unification variables. This returns a list of terms to substitute `x1`
+... `xN` with.  *)
+let unify_app (t fn: term) norm_steps: Tac (option (list term))
+  = let bds = fst (collect_arr_bs (tc (cur_env ()) fn)) in
+    let _fake_goal = 
+      (* create a goal `b1 -> ... -> bn -> squash True` *)
+      let trivial = pack_comp (C_Total (`squash True)) in
+      unshelve (fresh_uvar (Some (mk_arr bds trivial)))
+    in
+    (* get back the binders `b1`, ..., `bn` *)
+    let bds = intros () in
+    let args = map (fun (b: binder) -> b <: term) bds in
+    let norm_term = norm_term (hnf::norm_steps) in
+    let fn, t = norm_term (mk_e_app fn args), norm_term t in
+    let vars = map (fun b -> 
+      let b = inspect_binder b in
+      let {bv_index = uniq; bv_ppname = ppname} = inspect_bv b.binder_bv in
+      let nv: namedv_view = {uniq; ppname; sort = seal (`_)} in
+      (FStar.Reflection.V2.pack_namedv nv, b.binder_sort)
+    ) bds in
+    let?# substs = fst (try_unify (cur_env ()) vars fn t) in
+    if List.Tot.length substs <> List.Tot.length bds
+    then fail "unify_app: inconsistent lengths";
+    (* solve the trivial goal introduced at the begining *)
+    trivial ();
+    Some (List.Tot.rev (map (fun (_, t) -> t) substs))
+
+irreducible let add (x y: int): int = x + y
+
+let f (a b c d: int): int = add (add (add a b) c) d
+
+// #push-options "--print_full_names --print_implicits --print_bound_var_types"
+let _ = assert true by (
+  let r = 
+    unify_app 
+      (quote (f 1 2 3 4))
+      (quote f)
+      [delta_only [`%f]]
+  in
+  let s = term_to_string (quote r)
+  in
+ print s
+  )
+
+let test x y (#[(
+    let n = fresh_namedv () in
+    let y = quote y in
+    let y' = `(madd_rhs (`#n)) in
+    let n = FStar.Reflection.V2.pack_namedv n in
+    let t = match try_unify (cur_env ()) [(n,`(n: nat {n < 16}))] y y' with
+    | (Some [v, t'], _) -> 
+      `(stupid (`#t'))
+    | _ -> `(stupid (`#y)) in
+    exact t
+)]f: bit_vec 256 -> bit_vec 256) = f x
+
+let xx = fun x -> test x (madd_rhs 12)
+
+irreducible let vec256_to_i16s (bv: bit_vec 256)
+  : (i16 & i16 & i16 & i16 & i16 & i16 & i16 & i16)
+  & (i16 & i16 & i16 & i16 & i16 & i16 & i16 & i16)
+  = admit ()
+
+irreducible let rw_vec256_to_i16_ints
+  (x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12 x13 x14 x15: i16)
+  : Lemma (
+    vec256_to_i16s (mm256_set_epi16 x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12 x13 x14 x15)
+    == ((x0, x1, x2, x3, x4, x5, x6, x7), (x8, x9, x10, x11, x12, x13, x14, x15))
+  ) = admit ()
+
+let madd_rhs (n: nat {n < 16}) = 
+  mm256_set_epi16 
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s 
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s 
+    (1s <<! Int32.int_to_t n <: i16)
+    1s 
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s 
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s 
+    (1s <<! Int32.int_to_t n <: i16) 
+    1s
+
+#push-options "--z3rlimit 100"
+let to_madd_rhs (data: (i16 & i16 & i16 & i16 & i16 & i16 & i16 & i16)
+  & (i16 & i16 & i16 & i16 & i16 & i16 & i16 & i16))
+  : option (n:nat{
+    n < 16 /\ (
+      let ((x0, x1, x2, x3, x4, x5, x6, x7), (x8, x9, x10, x11, x12, x13, x14, x15)) = data in
+      madd_rhs n == mm256_set_epi16 x0 x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12 x13 x14 x15
+    )
+  })
+  = let ((x0, x1, x2, x3, x4, x5, x6, x7), (x8, x9, x10, x11, x12, x13, x14, x15)) = data in
+    if   v x0 >= 1
+      && v x0 = v x2 && v x0 = v x4  && v x0 = v x6  && v x0 = v x8 
+                     && v x0 = v x10 && v x0 = v x12 && v x0 = v x14
+      && v x1 = 1    && v x3 = 1     && v x5 = 1     && v x7 = 1 
+                     && v x9 = 1    && v x11= 1     && v x13= 1     && v x15= 1
+    then match Tactics.Pow2.log2 (v x0 <: nat) with
+       | Some coef -> 
+         if coef < 16
+         then (
+           assert (v ((1s <<! Int32.int_to_t coef <: i16)) == v x0);
+           Some coef
+         ) else None
+       | _ -> None
+    else None
+#pop-options
+
+open FStar.Tactics.V2
+[@@FStar.Tactics.V2.postprocess_with (fun _ -> 
+  compute ();
+  Tactics.Seq.norm_index ();
+  compute ();
+  fail "x"
+)]
+let aa =
+  let n = 12 in
+  let tuple = (
+    ( (1s <<! Int32.int_to_t n <: i16) 
+    , 1s 
+    , (1s <<! Int32.int_to_t n <: i16) 
+    , 1s
+    , (1s <<! Int32.int_to_t n <: i16) 
+    , 1s 
+    , (1s <<! Int32.int_to_t n <: i16)
+    , 1s),
+    ( (1s <<! Int32.int_to_t n <: i16)
+    , 1s 
+    , (1s <<! Int32.int_to_t n <: i16) 
+    , 1s
+    , (1s <<! Int32.int_to_t n <: i16) 
+    , 1s 
+    , (1s <<! Int32.int_to_t n <: i16) 
+    , 1s)) in
+  let x: nat = match to_madd_rhs tuple with | Some n -> n | None -> 0 in
+  x
+
+open Tactics.Utils
+open FStar.Tactics.V2
+module Visit = FStar.Tactics.Visit
+
+let rec any (f: 'a -> bool) (l: list 'a): bool
+    = match l with
+    | [] -> false
+    | hd::tl -> if f hd
+              then true
+              else any f tl
+
+exception FoundFreeLocalVar
+let is_closed_term (x: term): Tac bool
+  = try
+      let _ = FStar.Tactics.Visit.visit_tm (
+        function 
+        | Tv_Var _ | Tv_BVar _ -> raise FoundFreeLocalVar
+        | x -> x
+        ) x
+      in true
+    with | FoundFreeLocalVar -> false
+         | e -> raise e
+
+let rw_mm256_set_epi16 t = 
+  let?# (f, [arg,_]) = expect_app_n t 1 in
+  let?# _ = expect_free_var f (`%vec256_to_i16_ints) in
+  let?? _ = is_closed_term arg in
+  let?# (f, args) = expect_app_n arg 16 in
+  let?# _ = expect_free_var f (`%mm256_set_epi16) in
+  pointwise' (fun _ ->
+    let _ = let?# (lhs, _, _) = expect_lhs_eq_rhs () in
+            Some (if any (fun (arg, _) -> term_eq lhs arg) args 
+                  then norm [primops; iota; delta; zeta_full]
+                  else ())
+    in trefl ()
+  );
+  Some ()
+
+let rec expect_madd_rhs' (bv: bit_vec 256) (n:nat {n < 16})
+  : result: option (n: nat {n < 16}) { match result with
+                                   | Some n -> bv == madd_rhs n
+                                   | _ -> True
+                                   }
+  = if bv_equality bv (madd_rhs n)
+    then ( bv_equality_elim bv (madd_rhs n);
+           Some n )
+    else if n = 0 then None
+         else expect_madd_rhs' bv (n - 1)
+
+irreducible let expect_madd_rhs (bv: bit_vec 256): option (n: nat {n < 16})
+  = expect_madd_rhs' bv 15
+
+// let rewrite_expect_madd_rhs
+//   (bv: bit_vec 256) (n: nat {n < 16})
+//   : Lemma (requires bv == madd_rhs n)
+//           (ensures  )
+//   = ()
+