Implement SIMD splats using Convert (WebAssembly#274)

i8x16, i16x8, i32x4, i64x2, f32x4, f64x2 splats.

Implemented using Convert ast as a splat essentially takes a value of
every other type to V128.

interpreter/exec/eval_numeric.ml

@@ -293,12 +293,17 @@ end
 
 module V128CvtOp =
 struct
-  (* TODO
   open Ast.SimdOp
-  *)
 
-  (* FIXME *)
-  let cvtop op v = failwith "TODO v128"
+  let cvtop op v : value =
+    match op with
+    | I8x16 Splat -> V128 (V128.I8x16.splat (I32Op.of_value 1 v))
+    | I16x8 Splat -> V128 (V128.I16x8.splat (I32Op.of_value 1 v))
+    | I32x4 Splat -> V128 (V128.I32x4.splat (I32Op.of_value 1 v))
+    | I64x2 Splat -> V128 (V128.I64x2.splat (I64Op.of_value 1 v))
+    | F32x4 Splat -> V128 (V128.F32x4.splat (F32Op.of_value 1 v))
+    | F64x2 Splat -> V128 (V128.F64x2.splat (F64Op.of_value 1 v))
+    | _ -> assert false
 end
 
 let eval_extractop extractop v = V128Op.extractop extractop v

interpreter/exec/simd.ml

@@ -46,6 +46,7 @@ sig
   type t
   type lane
 
+  val splat : lane -> t
   val extract_lane : int -> t -> lane
   val abs : t -> t
   val neg : t -> t
@@ -67,6 +68,8 @@ sig
   type t
   type lane
 
+  val splat : lane -> t
+  val extract_lane : int -> t -> lane
   val abs : t -> t
   val neg : t -> t
   val sqrt : t -> t
@@ -76,7 +79,6 @@ sig
   val div : t -> t -> t
   val min : t -> t -> t
   val max : t -> t -> t
-  val extract_lane : int -> t -> lane
 end
 
 module type Vec =
@@ -148,6 +150,7 @@ struct
   module MakeFloat (Float : Float.S) (Convert : sig
       val to_shape : Rep.t -> Float.t list
       val of_shape : Float.t list -> Rep.t
+      val num_lanes : int
     end) : Float with type t = Rep.t and type lane = Float.t =
   struct
     type t = Rep.t
@@ -163,16 +166,19 @@ struct
     let div = binop Float.div
     let min = binop Float.min
     let max = binop Float.max
+    let splat x = Convert.of_shape (List.init Convert.num_lanes (fun i -> x))
     let extract_lane i s = List.nth (Convert.to_shape s) i
   end
 
   module MakeInt (Int : Int.S) (Convert : sig
       val to_shape : Rep.t -> Int.t list
       val of_shape : Int.t list -> Rep.t
+      val num_lanes : int
     end) : Int with type t = Rep.t and type lane = Int.t =
   struct
     type t = Rep.t
     type lane = Int.t
+    let splat x = Convert.of_shape (List.init Convert.num_lanes (fun i -> x))
     let extract_lane i s = List.nth (Convert.to_shape s) i
     let unop f x = Convert.of_shape (List.map f (Convert.to_shape x))
     let binop f x y = Convert.of_shape (List.map2 f (Convert.to_shape x) (Convert.to_shape y))
@@ -197,31 +203,37 @@ struct
   module I8x16 = MakeInt (I8) (struct
       let to_shape = Rep.to_i8x16
       let of_shape = Rep.of_i8x16
+      let num_lanes = lanes I8x16
     end)
 
   module I16x8 = MakeInt (I16) (struct
       let to_shape = Rep.to_i16x8
       let of_shape = Rep.of_i16x8
+      let num_lanes = lanes I16x8
     end)
 
   module I32x4 = MakeInt (I32) (struct
       let to_shape = Rep.to_i32x4
       let of_shape = Rep.of_i32x4
+      let num_lanes = lanes I32x4
     end)
 
   module I64x2 = MakeInt (I64) (struct
       let to_shape = Rep.to_i64x2
       let of_shape = Rep.of_i64x2
+      let num_lanes = lanes I64x2
     end)
 
   module F32x4 = MakeFloat (F32) (struct
       let to_shape = Rep.to_f32x4
       let of_shape = Rep.of_f32x4
+      let num_lanes = lanes F32x4
     end)
 
   module F64x2 = MakeFloat (F64) (struct
       let to_shape = Rep.to_f64x2
       let of_shape = Rep.of_f64x2
+      let num_lanes = lanes F64x2
     end)
 
 end

interpreter/syntax/ast.ml

@@ -70,7 +70,8 @@ struct
   type testop = (vtestop, vtestop, vtestop, vtestop, vtestop, vtestop, vtestop) v128op
   type ternop = Bitselect
   type relop = TodoRelOp
-  type cvtop = TodoCvtOp
+  type vcvtop = Splat
+  type cvtop = (vcvtop, vcvtop, vcvtop, vcvtop, vcvtop, vcvtop, vcvtop) v128op
   type extractop = I32x4ExtractLane of int | F32x4ExtractLane of int
 end
 

interpreter/syntax/operators.ml

@@ -224,6 +224,7 @@ let v128_or = Binary (V128 (V128Op.V128 V128Op.Or))
 let v128_xor = Binary (V128 (V128Op.V128 V128Op.Xor))
 let v128_bitselect = Ternary (V128Op.Bitselect)
 
+let i8x16_splat = Convert (V128 (V128Op.I8x16 V128Op.Splat))
 let i8x16_neg = Unary (V128 (V128Op.I8x16 V128Op.Neg))
 let i8x16_any_true = Test (V128 (V128Op.I8x16 V128Op.AnyTrue))
 let i8x16_all_true = Test (V128 (V128Op.I8x16 V128Op.AllTrue))
@@ -236,6 +237,7 @@ let i8x16_max_s = Binary (V128 (V128Op.I8x16 V128Op.MaxS))
 let i8x16_max_u = Binary (V128 (V128Op.I8x16 V128Op.MaxU))
 let i8x16_avgr_u = Binary (V128 (V128Op.I8x16 V128Op.AvgrU))
 
+let i16x8_splat = Convert (V128 (V128Op.I16x8 V128Op.Splat))
 let i16x8_neg = Unary (V128 (V128Op.I16x8 V128Op.Neg))
 let i16x8_any_true = Test (V128 (V128Op.I16x8 V128Op.AnyTrue))
 let i16x8_all_true = Test (V128 (V128Op.I16x8 V128Op.AllTrue))
@@ -249,6 +251,7 @@ let i16x8_max_s = Binary (V128 (V128Op.I16x8 V128Op.MaxS))
 let i16x8_max_u = Binary (V128 (V128Op.I16x8 V128Op.MaxU))
 let i16x8_avgr_u = Binary (V128 (V128Op.I16x8 V128Op.AvgrU))
 
+let i32x4_splat = Convert (V128 (V128Op.I32x4 V128Op.Splat))
 let i32x4_extract_lane imm = ExtractLane (V128Op.I32x4ExtractLane imm)
 let i32x4_abs = Unary (V128 (V128Op.I32x4 V128Op.Abs))
 let i32x4_neg = Unary (V128 (V128Op.I32x4 V128Op.Neg))
@@ -262,11 +265,13 @@ let i32x4_max_s = Binary (V128 (V128Op.I32x4 V128Op.MaxS))
 let i32x4_max_u = Binary (V128 (V128Op.I32x4 V128Op.MaxU))
 let i32x4_mul = Binary (V128 (V128Op.I32x4 V128Op.Mul))
 
+let i64x2_splat = Convert (V128 (V128Op.I64x2 V128Op.Splat))
 let i64x2_neg = Unary (V128 (V128Op.I64x2 V128Op.Neg))
 let i64x2_add = Binary (V128 (V128Op.I64x2 V128Op.Add))
 let i64x2_sub = Binary (V128 (V128Op.I64x2 V128Op.Sub))
 let i64x2_mul = Binary (V128 (V128Op.I64x2 V128Op.Mul))
 
+let f32x4_splat = Convert (V128 (V128Op.F32x4 V128Op.Splat))
 let f32x4_extract_lane imm = ExtractLane (V128Op.F32x4ExtractLane imm)
 let f32x4_abs = Unary (V128 (V128Op.F32x4 V128Op.Abs))
 let f32x4_neg = Unary (V128 (V128Op.F32x4 V128Op.Neg))
@@ -278,6 +283,7 @@ let f32x4_div = Binary (V128 (V128Op.F32x4 V128Op.Div))
 let f32x4_min = Binary (V128 (V128Op.F32x4 V128Op.Min))
 let f32x4_max = Binary (V128 (V128Op.F32x4 V128Op.Max))
 
+let f64x2_splat = Convert (V128 (V128Op.F64x2 V128Op.Splat))
 let f64x2_neg = Unary (V128 (V128Op.F64x2 V128Op.Neg))
 let f64x2_sqrt = Unary (V128 (V128Op.F64x2 V128Op.Sqrt))
 let f64x2_add = Binary (V128 (V128Op.F64x2 V128Op.Add))

interpreter/text/lexer.mll

@@ -244,6 +244,9 @@ rule token = parse
   | "global.get" { GLOBAL_GET }
   | "global.set" { GLOBAL_SET }
 
+  | (simd_shape as s)".splat"
+    { SPLAT (simdop s i8x16_splat i16x8_splat i32x4_splat
+                      i64x2_splat f32x4_splat f64x2_splat) }
   | (simd_shape as s)".extract_lane"
     { EXTRACT_LANE (fun imm ->
         simdop s unimplemented_simd unimplemented_simd i32x4_extract_lane

interpreter/valid/valid.ml

@@ -135,7 +135,15 @@ let type_cvtop at = function
     | PromoteF32 -> F32Type
     | DemoteF64 -> error at "invalid conversion"
     ), F64Type
-  | Values.V128 cvtop -> failwith "TODO v128"
+  | Values.V128 cvtop ->
+    let open V128Op in
+    (match cvtop with
+    | I8x16 Splat | I16x8 Splat | I32x4 Splat -> I32Type
+    | I64x2 Splat -> I64Type
+    | F32x4 Splat -> F32Type
+    | F64x2 Splat -> F64Type
+    | V128 Splat -> error at "invalid conversion"
+    ), V128Type
 
 
 (* Expressions *)