Alternative approach

Author: shulhi

jscomp/core/lam.ml

@@ -468,10 +468,16 @@ end
 
 let prim ~primitive:(prim : Lam_primitive.t) ~args loc : t =
   let default () : t = Lprim { primitive = prim; args; loc } in
+  let extract_const_as c def = 
+    (match c with 
+    | Lam_constant.Pt_constructor({cstr_name = ({tag_type = Some(Int(v))})}) -> Int32.of_int v
+    | _ -> def) in
   match args with
   | [ Lconst a ] -> (
       match (prim, a) with
-      | Pnegint, Const_int { i } -> Lift.int (Int32.neg i)
+      | Pnegint, Const_int { i; comment = pointer_info} -> 
+          let ii = extract_const_as pointer_info i in
+          Lift.int (Int32.neg ii)
       (* | Pfloatofint, ( (Const_int a)) *)
       (*   -> Lift.float (float_of_int a) *)
       | Pintoffloat, Const_float a ->
@@ -503,8 +509,10 @@ let prim ~primitive:(prim : Lam_primitive.t) ~args loc : t =
             | _ -> assert false)
       | ( ( Paddint | Psubint | Pmulint | Pdivint | Pmodint | Pandint | Porint
           | Pxorint | Plslint | Plsrint | Pasrint ),
-          Const_int { i = aa },
-          Const_int { i = bb } ) -> (
+          Const_int { i = aa; comment = aa_pointer_info },
+          Const_int { i = bb; comment = bb_pointer_info } ) -> (
+          let aa = extract_const_as aa_pointer_info aa in 
+          let bb = extract_const_as bb_pointer_info bb in 
           (* WE SHOULD keep it as [int], to preserve types *)
           let int_ = Lift.int in
           match prim with

jscomp/core/lam_constant_convert.ml

@@ -50,9 +50,6 @@ let rec convert_constant (const : Lambda.structured_constant) : Lam_constant.t =
           Const_int { i = Int32.of_int i; comment = Pt_assertfalse }
       | Pt_constructor { name; const; non_const; attrs } ->
           let tag_type = Ast_untagged_variants.process_tag_type attrs in
-          let i = match tag_type with
-            | Some(Ast_untagged_variants.Int(v)) -> v
-            | _ -> i in
           Const_int
             {
               i = Int32.of_int i;

jscomp/test/VariantCoercion.js

@@ -124,13 +124,15 @@ module CoerceFromPolyvariantToVariant = {
 module CoerceVariantBinaryOp = {
   type flag = | @as(0) A | @as(2) B
 
-  let x = 0->lor((B :> int))
+  let x1 = 0->lor((B :> int))
+  let x2 = -(B :> int)
 
   type flagStr = | @as("one") One | @as("two") Two
 
   let y = (One :> string)->String.length
 
   type flagFloat = | @as(1.5) X | @as(2.0) Y
 
-  let z = (X :> float) +. (Y :> float) +. 1.5
+  let z1 = (X :> float) +. (Y :> float) +. 1.5
+  let z2 = int_of_float((X :> float))
 }