diff --git a/jscomp/ext_ident.ml b/jscomp/ext_ident.ml
index aab3ac1c9c..0ff91c3ced 100644
--- a/jscomp/ext_ident.ml
+++ b/jscomp/ext_ident.ml
@@ -225,6 +225,7 @@ let convert (name : string) =
      | '|' -> Buffer.add_string buffer "$pipe"
      | '.' -> Buffer.add_string buffer "$dot"
      | '%' -> Buffer.add_string buffer "$percent"
+     | '~' -> Buffer.add_string buffer "$tilde"
      | 'a'..'z' | 'A'..'Z'| '_'|'$' |'0'..'9'-> Buffer.add_char buffer  c
      | _ -> Buffer.add_string buffer "$unknown"
    done; Buffer.contents buffer)
diff --git a/jscomp/ext_pervasives.ml b/jscomp/ext_pervasives.ml
index e31fe5cc4b..1df0491c53 100644
--- a/jscomp/ext_pervasives.ml
+++ b/jscomp/ext_pervasives.ml
@@ -40,3 +40,14 @@ let with_file_as_pp filename f =
       Format.pp_print_flush fmt ();
       v
     ) close_out
+
+
+let  is_pos_pow n = 
+  let module M = struct exception E end in 
+  let rec aux c (n : Int32.t) = 
+    if n <= 0l then -2 
+    else if n = 1l then c 
+    else if Int32.logand n 1l =  0l then   
+      aux (c + 1) (Int32.shift_right n 1 )
+    else raise M.E in 
+  try aux 0 n  with M.E -> -1
diff --git a/jscomp/ext_pervasives.mli b/jscomp/ext_pervasives.mli
index bd47a063f1..61768a8b62 100644
--- a/jscomp/ext_pervasives.mli
+++ b/jscomp/ext_pervasives.mli
@@ -29,3 +29,5 @@ val finally : 'a -> ('a -> 'b) -> ('a -> 'c) -> 'b
 val with_file_as_chan : string -> (out_channel -> 'a) -> 'a
 
 val with_file_as_pp : string -> (Format.formatter -> 'a) -> 'a
+
+val is_pos_pow : Int32.t -> int
diff --git a/jscomp/js_analyzer.ml b/jscomp/js_analyzer.ml
index 033445c8e6..ffab6dc1e2 100644
--- a/jscomp/js_analyzer.ml
+++ b/jscomp/js_analyzer.ml
@@ -71,8 +71,8 @@ let free_variables_of_statement used_idents defined_idents st =
 let free_variables_of_expression used_idents defined_idents st = 
   ((free_variables used_idents defined_idents)#expression st) # get_depenencies
 
-let rec no_side_effect (x : J.expression)  = 
-  match x.expression_desc with 
+let rec no_side_effect_expression_desc (x : J.expression_desc)  = 
+  match x with 
   | Bool _ -> true 
   | Var _ -> true 
   | Access (a,b) -> no_side_effect a && no_side_effect b 
@@ -125,6 +125,8 @@ let rec no_side_effect (x : J.expression)  =
   | Caml_block_set_tag _ 
   | Caml_block_set_length _ (* actually true? *)
     -> false 
+and no_side_effect (x : J.expression)  = 
+  no_side_effect_expression_desc x.expression_desc
 
 let no_side_effect_expression (x : J.expression) = no_side_effect x 
 
diff --git a/jscomp/js_analyzer.mli b/jscomp/js_analyzer.mli
index a97388ce43..aabf100d8a 100644
--- a/jscomp/js_analyzer.mli
+++ b/jscomp/js_analyzer.mli
@@ -31,8 +31,10 @@ val free_variables_of_statement :
 val free_variables_of_expression : 
     Ident_set.t -> Ident_set.t -> J.finish_ident_expression -> Ident_set.t
 
+val no_side_effect_expression_desc :
+  J.expression_desc -> bool   
 val no_side_effect_expression : 
-    J.expression -> bool
+  J.expression -> bool
 (** [no_side_effect] means this expression has no side effect, 
     but it might *depend on value store*, so you can not just move it around,
 
diff --git a/jscomp/js_exp_make.ml b/jscomp/js_exp_make.ml
index d94e67d2eb..7929f553d9 100644
--- a/jscomp/js_exp_make.ml
+++ b/jscomp/js_exp_make.ml
@@ -916,7 +916,7 @@ let to_uint32 ?comment (e : J.expression)  : J.expression =
    we can apply a more general optimization here, 
    do some algebraic rewerite rules to rewrite [triple_equal]           
 *)        
-let is_out ?comment (e : t) (range : t) : t  = 
+let rec is_out ?comment (e : t) (range : t) : t  = 
   begin match range.expression_desc, e.expression_desc with 
 
     | Number (Int {i = 1l}), Var _ 
@@ -925,8 +925,8 @@ let is_out ?comment (e : t) (range : t) : t  =
     | Number (Int {i = 1l}), 
       (
         Bin (Plus , {expression_desc = Number (Int {i ; _}) }, {expression_desc = Var _; _})
-      | Bin (Plus, {expression_desc = Var _; _}, {expression_desc = Number (Int {i ; _}) })
-      ) 
+      | Bin (Plus, {expression_desc = Var _; _}, {expression_desc = Number (Int {i ; _}) }))
+     
       ->
       not (or_ (triple_equal e (int (Int32.neg i ))) (triple_equal e (int (Int32.sub Int32.one  i))))        
     | Number (Int {i = 1l}), 
@@ -946,6 +946,16 @@ let is_out ?comment (e : t) (range : t) : t  =
       *)        
       or_ (int_comp Cgt e (int ( k)))  (int_comp Clt e  zero_int_literal)
 
+    | _, Bin (Bor ,
+             ({expression_desc =
+                (Bin((Plus | Minus ) ,
+                    {expression_desc = Number (Int {i ; _}) }, {expression_desc = Var _; _})
+                |Bin((Plus | Minus ) ,
+                    {expression_desc = Var _; _}, {expression_desc = Number (Int {i ; _}) } ))
+                } as e), {expression_desc = Number (Int {i=0l} | Uint 0l | Nint 0n); _})
+      ->  
+      (* TODO: check correctness *)
+      is_out ?comment e range 
     | _, _ ->
       int_comp ?comment Cgt (to_uint32 e)  range 
   end
@@ -1004,9 +1014,6 @@ let int32_minus ?comment e1 e2 : J.expression =
 let unchecked_int32_minus ?comment e1 e2 : J.expression = 
   float_minus ?comment e1 e2
 
-let unchecked_prefix_inc ?comment (i : J.vident)  = 
-  let v : t = {expression_desc = Var i; comment = None} in
-  assign ?comment  v (unchecked_int32_add v one_int_literal)
 
 
 let float_div ?comment e1 e2 = 
@@ -1034,22 +1041,6 @@ let int32_div ?comment (e1 : J.expression) (e2 : J.expression)
     to_int32 (float_div ?comment e1 e2)
 
 
-(* TODO: call primitive *)    
-let int32_mul ?comment 
-    (e1 : J.expression) 
-    (e2 : J.expression) : J.expression = 
-  match e1.expression_desc, e2.expression_desc with 
-  | Number (Int{i = i0}), Number (Int {i = i1})
-    -> int (Int32.mul i0 i1)
-  | _ -> 
-    { comment ; 
-      expression_desc = Bin (Mul, e1,e2)
-    }
-
-let unchecked_int32_mul ?comment e1 e2 : J.expression = 
-  { comment ; 
-    expression_desc = Bin (Mul, e1,e2)
-  }
 
 let float_mul ?comment e1 e2 = 
   bin ?comment Mul e1 e2 
@@ -1068,6 +1059,32 @@ let int32_lsl ?comment e1 e2 : J.expression =
   }
 
 
+let int32_mul ?comment 
+    (e1 : J.expression) 
+    (e2 : J.expression) : J.expression = 
+  match e1, e2 with 
+  | {expression_desc = Number (Int {i = 0l}|  Uint 0l | Nint 0n); _}, x
+  | x, {expression_desc = Number (Int {i = 0l}|  Uint 0l | Nint 0n); _} 
+    when Js_analyzer.no_side_effect_expression x 
+    -> zero_int_literal
+  | {expression_desc = Number (Int{i = i0}); _}, {expression_desc = Number (Int {i = i1}); _}
+    -> int (Int32.mul i0 i1)
+  | e , {expression_desc = Number (Int {i = i0} | Uint i0 ); _}
+  | {expression_desc = Number (Int {i = i0} | Uint i0 ); _}, e 
+    -> 
+    let i =  Ext_pervasives.is_pos_pow i0  in 
+    if i >= 0 then 
+      int32_lsl e (small_int i)
+    else 
+      runtime_call ?comment Js_config.prim "imul" [e1;e2]
+  | _ -> 
+    runtime_call ?comment Js_config.prim "imul" [e1;e2]
+
+let unchecked_int32_mul ?comment e1 e2 : J.expression = 
+  { comment ; 
+    expression_desc = Bin (Mul, e1,e2)
+  }
+
 
 
 let rec int32_bxor ?comment (e1 : t) (e2 : t) : J.expression = 
diff --git a/jscomp/js_exp_make.mli b/jscomp/js_exp_make.mli
index cc4b097baa..7f2f228fa3 100644
--- a/jscomp/js_exp_make.mli
+++ b/jscomp/js_exp_make.mli
@@ -228,9 +228,6 @@ val inc : unary_op
 
 val dec : unary_op
 
-val unchecked_prefix_inc : ?comment:string -> J.vident -> t
-
-
 
 
 
diff --git a/jscomp/lam_compile.ml b/jscomp/lam_compile.ml
index 7ef84957b4..6bbe414333 100644
--- a/jscomp/lam_compile.ml
+++ b/jscomp/lam_compile.ml
@@ -1194,7 +1194,7 @@ and
         match lambda with
         | Lprim(Poffsetint  v, [Lvar id']) when Ident.same id id' ->
           [ S.exp (E.assign (E.var id) 
-                     (E.unchecked_int32_add (E.var id) (E.small_int  v)))
+                     (E.int32_add (E.var id) (E.small_int  v)))
           ]
         | _ ->
           begin 
diff --git a/jscomp/lam_compile_primitive.ml b/jscomp/lam_compile_primitive.ml
index 4f6bb66f1d..139553ea4e 100644
--- a/jscomp/lam_compile_primitive.ml
+++ b/jscomp/lam_compile_primitive.ml
@@ -81,12 +81,6 @@ let translate
 (** Negate boxed int end*)
 (* Int addition and subtraction *)
   | Paddint 
-    -> 
-      begin match args with 
-      | [e1; e2] 
-        -> E.unchecked_int32_add e1 e2
-      | _ -> assert false 
-      end
   | Paddbint  Pint32
     ->
     begin match args with
@@ -340,14 +334,14 @@ let translate
     end
   | Poffsetint n ->
     begin match args with
-      | [e] ->  E.unchecked_int32_add  e (E.small_int  n)
+      | [e] ->  E.int32_add  e (E.small_int  n)
       | _ -> assert false
     end
   | Poffsetref n ->
     begin match args with
       | [e] -> 
         let v = (Js_of_lam_block.field Fld_na e 0l) in
-        E.assign  v (E.unchecked_int32_add v (E.small_int  n))
+        E.assign  v (E.int32_add v (E.small_int  n))
       | _ -> assert false
     end
 
diff --git a/jscomp/runtime/caml_array.js b/jscomp/runtime/caml_array.js
index 5402b386d5..97e05ec4bd 100644
--- a/jscomp/runtime/caml_array.js
+++ b/jscomp/runtime/caml_array.js
@@ -8,8 +8,8 @@ function caml_array_sub(x, offset, len) {
   var i = offset;
   while(j < len) {
     result[j] = x[i];
-    ++ j;
-    ++ i;
+    j = j + 1 | 0;
+    i = i + 1 | 0;
   };
   return result;
 }
@@ -20,7 +20,7 @@ function len(_acc, _l) {
     var acc = _acc;
     if (l) {
       _l = l[1];
-      _acc = l[0].length + acc;
+      _acc = l[0].length + acc | 0;
       continue ;
       
     }
@@ -41,8 +41,8 @@ function fill(arr, _i, _l) {
       var j = 0;
       while(j < l$1) {
         arr[k] = x[j];
-        ++ k;
-        ++ j;
+        k = k + 1 | 0;
+        j = j + 1 | 0;
       };
       _l = l[1];
       _i = k;
@@ -73,13 +73,13 @@ function caml_make_vect(len, init) {
 function caml_array_blit(a1, i1, a2, i2, len) {
   if (i2 <= i1) {
     for(var j = 0 ,j_finish = len - 1; j<= j_finish; ++j){
-      a2[j + i2] = a1[j + i1];
+      a2[j + i2 | 0] = a1[j + i1 | 0];
     }
     return /* () */0;
   }
   else {
     for(var j$1 = len - 1; j$1>= 0; --j$1){
-      a2[j$1 + i2] = a1[j$1 + i1];
+      a2[j$1 + i2 | 0] = a1[j$1 + i1 | 0];
     }
     return /* () */0;
   }
diff --git a/jscomp/runtime/caml_format.js b/jscomp/runtime/caml_format.js
index 7f9c675f7d..0713510b60 100644
--- a/jscomp/runtime/caml_format.js
+++ b/jscomp/runtime/caml_format.js
@@ -3,6 +3,7 @@
 
 var Caml_int64              = require("./caml_int64");
 var Caml_builtin_exceptions = require("./caml_builtin_exceptions");
+var Caml_primitive          = require("./caml_primitive");
 var Caml_utils              = require("./caml_utils");
 var Caml_string             = require("./caml_string");
 
@@ -65,46 +66,46 @@ function parse_sign_and_base(s) {
   var i = 0;
   if (s[i] === "-") {
     sign = -1;
-    ++ i;
+    i = i + 1 | 0;
   }
   var match = s.charCodeAt(i);
-  var match$1 = s.charCodeAt(i + 1);
+  var match$1 = s.charCodeAt(i + 1 | 0);
   if (match === 48) {
     if (match$1 >= 89) {
       if (match$1 !== 98) {
         if (match$1 !== 111) {
           if (match$1 === 120) {
             base = /* Hex */1;
-            i += 2;
+            i = i + 2 | 0;
           }
           
         }
         else {
           base = /* Oct */0;
-          i += 2;
+          i = i + 2 | 0;
         }
       }
       else {
         base = /* Bin */3;
-        i += 2;
+        i = i + 2 | 0;
       }
     }
     else if (match$1 !== 66) {
       if (match$1 !== 79) {
         if (match$1 >= 88) {
           base = /* Hex */1;
-          i += 2;
+          i = i + 2 | 0;
         }
         
       }
       else {
         base = /* Oct */0;
-        i += 2;
+        i = i + 2 | 0;
       }
     }
     else {
       base = /* Bin */3;
-      i += 2;
+      i = i + 2 | 0;
     }
   }
   return /* tuple */[
@@ -138,7 +139,7 @@ function caml_int_of_string(s) {
       else {
         var a = s.charCodeAt(k);
         if (a === /* "_" */95) {
-          _k = k + 1;
+          _k = k + 1 | 0;
           continue ;
           
         }
@@ -159,7 +160,7 @@ function caml_int_of_string(s) {
                   ];
             }
             else {
-              _k = k + 1;
+              _k = k + 1 | 0;
               _acc = acc$1;
               continue ;
               
@@ -169,7 +170,7 @@ function caml_int_of_string(s) {
       }
     };
   };
-  var res = match[1] * aux(d, i + 1);
+  var res = match[1] * aux(d, i + 1 | 0);
   var or_res = res | 0;
   if (base === 10 && res !== or_res) {
     throw [
@@ -236,7 +237,7 @@ function caml_int64_of_string(s) {
       else {
         var a = s.charCodeAt(k);
         if (a === /* "_" */95) {
-          _k = k + 1;
+          _k = k + 1 | 0;
           continue ;
           
         }
@@ -260,7 +261,7 @@ function caml_int64_of_string(s) {
                   ];
             }
             else {
-              _k = k + 1;
+              _k = k + 1 | 0;
               _acc = acc$1;
               continue ;
               
@@ -270,7 +271,7 @@ function caml_int64_of_string(s) {
       }
     };
   };
-  var res = Caml_int64.mul(sign, aux(d, i + 1));
+  var res = Caml_int64.mul(sign, aux(d, i + 1 | 0));
   var or_res_000 = res[0] | 0;
   var or_res_001 = (res[1] >>> 0);
   var or_res = /* int64 */[
@@ -303,7 +304,7 @@ function int_of_base(param) {
 
 function lowercase(c) {
   if (c >= /* "A" */65 && c <= /* "Z" */90 || c >= /* "\192" */192 && c <= /* "\214" */214 || c >= /* "\216" */216 && c <= /* "\222" */222) {
-    return c + 32;
+    return c + 32 | 0;
   }
   else {
     return c;
@@ -346,11 +347,11 @@ function parse_format(fmt) {
             exit = 1;
           }
           else {
-            switch (c - 88) {
+            switch (c - 88 | 0) {
               case 0 : 
                   f[/* base */4] = /* Hex */1;
                   f[/* uppercase */7] = /* true */1;
-                  _i = i + 1;
+                  _i = i + 1 | 0;
                   continue ;
                   case 13 : 
               case 14 : 
@@ -363,11 +364,11 @@ function parse_format(fmt) {
                   break;
               case 23 : 
                   f[/* base */4] = /* Oct */0;
-                  _i = i + 1;
+                  _i = i + 1 | 0;
                   continue ;
                   case 29 : 
                   f[/* base */4] = /* Dec */2;
-                  _i = i + 1;
+                  _i = i + 1 | 0;
                   continue ;
                   case 1 : 
               case 2 : 
@@ -397,7 +398,7 @@ function parse_format(fmt) {
                   break;
               case 32 : 
                   f[/* base */4] = /* Hex */1;
-                  _i = i + 1;
+                  _i = i + 1 | 0;
                   continue ;
                   
             }
@@ -410,13 +411,13 @@ function parse_format(fmt) {
           f[/* signedconv */5] = /* true */1;
           f[/* uppercase */7] = /* true */1;
           f[/* conv */10] = String.fromCharCode(lowercase(c));
-          _i = i + 1;
+          _i = i + 1 | 0;
           continue ;
           
         }
       }
       else {
-        var switcher = c - 32;
+        var switcher = c - 32 | 0;
         if (switcher > 25 || switcher < 0) {
           exit = 1;
         }
@@ -424,7 +425,7 @@ function parse_format(fmt) {
           switch (switcher) {
             case 3 : 
                 f[/* alternate */3] = /* true */1;
-                _i = i + 1;
+                _i = i + 1 | 0;
                 continue ;
                 case 0 : 
             case 11 : 
@@ -432,19 +433,19 @@ function parse_format(fmt) {
                 break;
             case 13 : 
                 f[/* justify */0] = "-";
-                _i = i + 1;
+                _i = i + 1 | 0;
                 continue ;
                 case 14 : 
                 f[/* prec */9] = 0;
-                var j = i + 1;
+                var j = i + 1 | 0;
                 while((function(j){
                     return function () {
                       var w = fmt.charCodeAt(j) - /* "0" */48;
                       return +(w >= 0 && w <= 9);
                     }
                     }(j))()) {
-                  f[/* prec */9] = f[/* prec */9] * 10 + fmt.charCodeAt(j) - /* "0" */48;
-                  ++ j;
+                  f[/* prec */9] = (Caml_primitive.imul(f[/* prec */9], 10) + fmt.charCodeAt(j) | 0) - /* "0" */48;
+                  j = j + 1 | 0;
                 };
                 _i = j;
                 continue ;
@@ -463,7 +464,7 @@ function parse_format(fmt) {
                 break;
             case 16 : 
                 f[/* filter */2] = "0";
-                _i = i + 1;
+                _i = i + 1 | 0;
                 continue ;
                 case 17 : 
             case 18 : 
@@ -482,11 +483,11 @@ function parse_format(fmt) {
       }
       switch (exit) {
         case 1 : 
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             case 2 : 
             f[/* signstyle */1] = String.fromCharCode(c);
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             case 3 : 
             f[/* width */6] = 0;
@@ -497,20 +498,20 @@ function parse_format(fmt) {
                   return +(w >= 0 && w <= 9);
                 }
                 }(j$1))()) {
-              f[/* width */6] = f[/* width */6] * 10 + fmt.charCodeAt(j$1) - /* "0" */48;
-              ++ j$1;
+              f[/* width */6] = (Caml_primitive.imul(f[/* width */6], 10) + fmt.charCodeAt(j$1) | 0) - /* "0" */48;
+              j$1 = j$1 + 1 | 0;
             };
             _i = j$1;
             continue ;
             case 4 : 
             f[/* signedconv */5] = /* true */1;
             f[/* base */4] = /* Dec */2;
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             case 5 : 
             f[/* signedconv */5] = /* true */1;
             f[/* conv */10] = String.fromCharCode(c);
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             
       }
@@ -530,17 +531,17 @@ function finish_formatting(param, rawbuffer) {
   var sign = param[/* sign */8];
   var len = rawbuffer.length;
   if (signedconv && (sign < 0 || signstyle !== "-")) {
-    ++ len;
+    len = len + 1 | 0;
   }
   if (alternate) {
     if (base) {
       if (base === /* Hex */1) {
-        len += 2;
+        len = len + 2 | 0;
       }
       
     }
     else {
-      ++ len;
+      len = len + 1 | 0;
     }
   }
   var buffer = "";
@@ -745,16 +746,16 @@ function caml_format_float(fmt, x) {
           var prec$1 = prec !== 0 ? prec : 1;
           s = x$1.toExponential(prec$1 - 1);
           var j = s.indexOf("e");
-          var exp = +s.slice(j + 1);
+          var exp = +s.slice(j + 1 | 0);
           if (exp < -4 || x$1 >= 1e21 || x$1.toFixed(0).length > prec$1) {
             var i$1 = j - 1;
             while(s[i$1] === "0") {
-              -- i$1;
+              i$1 = i$1 - 1 | 0;
             };
             if (s[i$1] === ".") {
-              -- i$1;
+              i$1 = i$1 - 1 | 0;
             }
-            s = s.slice(0, i$1 + 1) + s.slice(j);
+            s = s.slice(0, i$1 + 1 | 0) + s.slice(j);
             var i$2 = s.length;
             if (s[i$2 - 3] === "e") {
               s = s.slice(0, i$2 - 1) + ("0" + s.slice(i$2 - 1));
@@ -764,26 +765,26 @@ function caml_format_float(fmt, x) {
           else {
             var p = prec$1;
             if (exp < 0) {
-              p -= (exp + 1);
+              p -= (exp + 1 | 0);
               s = x$1.toFixed(p);
             }
             else {
               while(function () {
                     s = x$1.toFixed(p);
-                    return +(s.length > prec$1 + 1);
+                    return +(s.length > (prec$1 + 1 | 0));
                   }()) {
-                -- p;
+                p = p - 1 | 0;
               };
             }
             if (p !== 0) {
               var k = s.length - 1;
               while(s[k] === "0") {
-                -- k;
+                k = k - 1 | 0;
               };
               if (s[k] === ".") {
-                -- k;
+                k = k - 1 | 0;
               }
-              s = s.slice(0, k + 1);
+              s = s.slice(0, k + 1 | 0);
             }
             
           }
diff --git a/jscomp/runtime/caml_io.js b/jscomp/runtime/caml_io.js
index 0ab1332ca7..111ba762f7 100644
--- a/jscomp/runtime/caml_io.js
+++ b/jscomp/runtime/caml_io.js
@@ -81,9 +81,9 @@ function caml_ml_output(oc, str, offset, len) {
       return /* () */0;
     }
     else {
-      oc[/* buffer */0] = oc[/* buffer */0] + str$1.slice(0, id + 1);
+      oc[/* buffer */0] = oc[/* buffer */0] + str$1.slice(0, id + 1 | 0);
       caml_ml_flush(oc);
-      oc[/* buffer */0] = oc[/* buffer */0] + str$1.slice(id + 1);
+      oc[/* buffer */0] = oc[/* buffer */0] + str$1.slice(id + 1 | 0);
       return /* () */0;
     }
   }
diff --git a/jscomp/runtime/caml_obj.js b/jscomp/runtime/caml_obj.js
index f23d9a8892..0b02dfaee6 100644
--- a/jscomp/runtime/caml_obj.js
+++ b/jscomp/runtime/caml_obj.js
@@ -134,7 +134,7 @@ function caml_compare(_a, _b) {
                 return res;
               }
               else {
-                _i = i + 1;
+                _i = i + 1 | 0;
                 continue ;
                 
               }
@@ -157,7 +157,7 @@ function caml_compare(_a, _b) {
                 return res$1;
               }
               else {
-                _i$1 = i$1 + 1;
+                _i$1 = i$1 + 1 | 0;
                 continue ;
                 
               }
@@ -180,7 +180,7 @@ function caml_compare(_a, _b) {
                 return res$2;
               }
               else {
-                _i$2 = i$2 + 1;
+                _i$2 = i$2 + 1 | 0;
                 continue ;
                 
               }
@@ -241,7 +241,7 @@ function caml_equal(_a, _b) {
               return /* true */1;
             }
             else if (caml_equal(a$1[i], b$1[i])) {
-              _i = i + 1;
+              _i = i + 1 | 0;
               continue ;
               
             }
diff --git a/jscomp/runtime/caml_oo.js b/jscomp/runtime/caml_oo.js
index 46c2bde69b..b96848bdc8 100644
--- a/jscomp/runtime/caml_oo.js
+++ b/jscomp/runtime/caml_oo.js
@@ -37,7 +37,7 @@ function caml_get_public_method(obj, tag, cacheid) {
         }
       };
     };
-    return meths[aux(meths[0] * 2 + 1) - 1];
+    return meths[aux((meths[0] << 1) + 1 | 0) - 1];
   }
 }
 
diff --git a/jscomp/runtime/caml_primitive.js b/jscomp/runtime/caml_primitive.js
index 91888fa088..a25f4728a8 100644
--- a/jscomp/runtime/caml_primitive.js
+++ b/jscomp/runtime/caml_primitive.js
@@ -60,6 +60,11 @@ function caml_convert_raw_backtrace_slot() {
       ];
 }
 
+var imul = ( Math.imul || function (x,y) {
+  y |= 0; return ((((x >> 16) * y) << 16) + (x & 0xffff) * y)|0; 
+}
+);
+
 function caml_hash(prim, prim$1, prim$2, prim$3) {
   return $$caml_hash(prim, prim$1, prim$2, prim$3);
 }
@@ -72,4 +77,5 @@ exports.caml_bswap16                    = caml_bswap16;
 exports.caml_int32_bswap                = caml_int32_bswap;
 exports.caml_nativeint_bswap            = caml_nativeint_bswap;
 exports.caml_convert_raw_backtrace_slot = caml_convert_raw_backtrace_slot;
+exports.imul                            = imul;
 /*  Not a pure module */
diff --git a/jscomp/runtime/caml_primitive.ml b/jscomp/runtime/caml_primitive.ml
index a7304da616..c989243e49 100644
--- a/jscomp/runtime/caml_primitive.ml
+++ b/jscomp/runtime/caml_primitive.ml
@@ -83,3 +83,8 @@ let caml_convert_raw_backtrace_slot : Printexc.raw_backtrace_slot -> Printexc. b
 let caml_md5_string : string -> int -> int -> t = function _ -> 
   function _ -> 
     raise @@ Failure "caml_md5_string unimplemented"
+
+let imul : int32 -> int32 -> int32 = [%js.raw{| Math.imul || function (x,y) {
+  y |= 0; return ((((x >> 16) * y) << 16) + (x & 0xffff) * y)|0; 
+}
+|}]
diff --git a/jscomp/runtime/caml_primitive.mli b/jscomp/runtime/caml_primitive.mli
index 7f4d565d89..3814a5068f 100644
--- a/jscomp/runtime/caml_primitive.mli
+++ b/jscomp/runtime/caml_primitive.mli
@@ -26,3 +26,5 @@ val caml_int32_bswap : nativeint -> nativeint
 val caml_nativeint_bswap : nativeint -> nativeint
 
 val caml_convert_raw_backtrace_slot : Printexc.raw_backtrace_slot -> Printexc. backtrace_slot
+
+val imul :int32 -> int32 -> int32
diff --git a/jscomp/runtime/caml_string.js b/jscomp/runtime/caml_string.js
index 79a9cfc8fc..f8430805b3 100644
--- a/jscomp/runtime/caml_string.js
+++ b/jscomp/runtime/caml_string.js
@@ -49,7 +49,7 @@ function caml_string_compare(s1, s2) {
 
 function caml_fill_string(s, i, l, c) {
   if (l > 0) {
-    for(var k = i ,k_finish = l + i - 1; k<= k_finish; ++k){
+    for(var k = i ,k_finish = (l + i | 0) - 1; k<= k_finish; ++k){
       s[k] = c;
     }
     return /* () */0;
@@ -64,16 +64,16 @@ function caml_blit_string(s1, i1, s2, i2, len) {
     var off1 = s1.length - i1;
     if (len <= off1) {
       for(var i = 0 ,i_finish = len - 1; i<= i_finish; ++i){
-        s2[i2 + i] = s1.charCodeAt(i1 + i);
+        s2[i2 + i | 0] = s1.charCodeAt(i1 + i | 0);
       }
       return /* () */0;
     }
     else {
       for(var i$1 = 0 ,i_finish$1 = off1 - 1; i$1<= i_finish$1; ++i$1){
-        s2[i2 + i$1] = s1.charCodeAt(i1 + i$1);
+        s2[i2 + i$1 | 0] = s1.charCodeAt(i1 + i$1 | 0);
       }
       for(var i$2 = off1 ,i_finish$2 = len - 1; i$2<= i_finish$2; ++i$2){
-        s2[i2 + i$2] = /* "\000" */0;
+        s2[i2 + i$2 | 0] = /* "\000" */0;
       }
       return /* () */0;
     }
@@ -88,16 +88,16 @@ function caml_blit_bytes(s1, i1, s2, i2, len) {
     var off1 = s1.length - i1;
     if (len <= off1) {
       for(var i = 0 ,i_finish = len - 1; i<= i_finish; ++i){
-        s2[i2 + i] = s1[i1 + i];
+        s2[i2 + i | 0] = s1[i1 + i | 0];
       }
       return /* () */0;
     }
     else {
       for(var i$1 = 0 ,i_finish$1 = off1 - 1; i$1<= i_finish$1; ++i$1){
-        s2[i2 + i$1] = s1[i1 + i$1];
+        s2[i2 + i$1 | 0] = s1[i1 + i$1 | 0];
       }
       for(var i$2 = off1 ,i_finish$2 = len - 1; i$2<= i_finish$2; ++i$2){
-        s2[i2 + i$2] = /* "\000" */0;
+        s2[i2 + i$2 | 0] = /* "\000" */0;
       }
       return /* () */0;
     }
@@ -133,7 +133,7 @@ function bytes_to_string(a) {
       caml_blit_bytes(bytes, offset, tmp_bytes, 0, next);
       s = s + String.fromCharCode.apply(null,tmp_bytes);
       s_len -= next;
-      offset += next;
+      offset = offset + next | 0;
     };
     return s;
   }
diff --git a/jscomp/runtime/caml_utils.js b/jscomp/runtime/caml_utils.js
index d4f45110b7..21d79d6d6f 100644
--- a/jscomp/runtime/caml_utils.js
+++ b/jscomp/runtime/caml_utils.js
@@ -3,15 +3,6 @@
 
 var Caml_builtin_exceptions = require("./caml_builtin_exceptions");
 
-
-if (!Math.imul){
-    Math.imul = function (x,y)
-        { y |= 0; return ((((x >> 16) * y) << 16) + (x & 0xffff) * y)|0; }
-}
-  
-
-;
-
 var repeat = ( (String.prototype.repeat && function (count,self){return self.repeat(count)}) ||
                                                   function(count , self) {
         if (self.length == 0 || count == 0) {
@@ -59,4 +50,4 @@ function i32mod(x, y) {
 exports.i32div = i32div;
 exports.i32mod = i32mod;
 exports.repeat = repeat;
-/*  Not a pure module */
+/* repeat Not a pure module */
diff --git a/jscomp/runtime/caml_utils.ml b/jscomp/runtime/caml_utils.ml
index 820624fe4b..3c12ee65c4 100644
--- a/jscomp/runtime/caml_utils.ml
+++ b/jscomp/runtime/caml_utils.ml
@@ -21,13 +21,6 @@
 
 (* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/imul *)
 
-[%%js.raw{|
-if (!Math.imul){
-    Math.imul = function (x,y)
-        { y |= 0; return ((((x >> 16) * y) << 16) + (x & 0xffff) * y)|0; }
-}
-  
-|}]
 
 let repeat : int -> string -> string = [%js.raw{| (String.prototype.repeat && function (count,self){return self.repeat(count)}) ||
                                                   function(count , self) {
diff --git a/jscomp/stdlib/arg.js b/jscomp/stdlib/arg.js
index 1fa1db3fa4..28356c9a59 100644
--- a/jscomp/stdlib/arg.js
+++ b/jscomp/stdlib/arg.js
@@ -424,7 +424,7 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
           ];
     }
   };
-  ++ current$1[0];
+  current$1[0] = current$1[0] + 1 | 0;
   while(current$1[0] < l) {
     var s = argv[current$1[0]];
     if (s.length >= 1 && s[0] === "-") {
@@ -451,8 +451,8 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
             case 0 : 
                 return Caml_curry.app1(param[0], /* () */0);
             case 1 : 
-                if (current$1[0] + 1 < l) {
-                  var arg = argv[current$1[0] + 1];
+                if ((current$1[0] + 1 | 0) < l) {
+                  var arg = argv[current$1[0] + 1 | 0];
                   try {
                     Caml_curry.app1(param[0], Pervasives.bool_of_string(arg));
                   }
@@ -478,7 +478,7 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                       throw exn;
                     }
                   }
-                  return ++ current$1[0];
+                  return current$1[0] = current$1[0] + 1 | 0;
                 }
                 else {
                   throw [
@@ -498,9 +498,9 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                 param[0][0] = /* false */0;
                 return /* () */0;
             case 4 : 
-                if (current$1[0] + 1 < l) {
-                  Caml_curry.app1(param[0], argv[current$1[0] + 1]);
-                  return ++ current$1[0];
+                if ((current$1[0] + 1 | 0) < l) {
+                  Caml_curry.app1(param[0], argv[current$1[0] + 1 | 0]);
+                  return current$1[0] = current$1[0] + 1 | 0;
                 }
                 else {
                   throw [
@@ -514,9 +514,9 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                 }
                 break;
             case 5 : 
-                if (current$1[0] + 1 < l) {
-                  param[0][0] = argv[current$1[0] + 1];
-                  return ++ current$1[0];
+                if ((current$1[0] + 1 | 0) < l) {
+                  param[0][0] = argv[current$1[0] + 1 | 0];
+                  return current$1[0] = current$1[0] + 1 | 0;
                 }
                 else {
                   throw [
@@ -530,8 +530,8 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                 }
                 break;
             case 6 : 
-                if (current$1[0] + 1 < l) {
-                  var arg$1 = argv[current$1[0] + 1];
+                if ((current$1[0] + 1 | 0) < l) {
+                  var arg$1 = argv[current$1[0] + 1 | 0];
                   try {
                     Caml_curry.app1(param[0], Caml_format.caml_int_of_string(arg$1));
                   }
@@ -557,7 +557,7 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                       throw exn$1;
                     }
                   }
-                  return ++ current$1[0];
+                  return current$1[0] = current$1[0] + 1 | 0;
                 }
                 else {
                   throw [
@@ -571,8 +571,8 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                 }
                 break;
             case 7 : 
-                if (current$1[0] + 1 < l) {
-                  var arg$2 = argv[current$1[0] + 1];
+                if ((current$1[0] + 1 | 0) < l) {
+                  var arg$2 = argv[current$1[0] + 1 | 0];
                   try {
                     param[0][0] = Caml_format.caml_int_of_string(arg$2);
                   }
@@ -598,7 +598,7 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                       throw exn$2;
                     }
                   }
-                  return ++ current$1[0];
+                  return current$1[0] = current$1[0] + 1 | 0;
                 }
                 else {
                   throw [
@@ -612,8 +612,8 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                 }
                 break;
             case 8 : 
-                if (current$1[0] + 1 < l) {
-                  var arg$3 = argv[current$1[0] + 1];
+                if ((current$1[0] + 1 | 0) < l) {
+                  var arg$3 = argv[current$1[0] + 1 | 0];
                   try {
                     Caml_curry.app1(param[0], Caml_format.caml_float_of_string(arg$3));
                   }
@@ -639,7 +639,7 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                       throw exn$3;
                     }
                   }
-                  return ++ current$1[0];
+                  return current$1[0] = current$1[0] + 1 | 0;
                 }
                 else {
                   throw [
@@ -653,8 +653,8 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                 }
                 break;
             case 9 : 
-                if (current$1[0] + 1 < l) {
-                  var arg$4 = argv[current$1[0] + 1];
+                if ((current$1[0] + 1 | 0) < l) {
+                  var arg$4 = argv[current$1[0] + 1 | 0];
                   try {
                     param[0][0] = Caml_format.caml_float_of_string(arg$4);
                   }
@@ -680,7 +680,7 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                       throw exn$4;
                     }
                   }
-                  return ++ current$1[0];
+                  return current$1[0] = current$1[0] + 1 | 0;
                 }
                 else {
                   throw [
@@ -697,11 +697,11 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
                 return List.iter(treat_action, param[0]);
             case 11 : 
                 var symb = param[0];
-                if (current$1[0] + 1 < l) {
-                  var arg$5 = argv[current$1[0] + 1];
+                if ((current$1[0] + 1 | 0) < l) {
+                  var arg$5 = argv[current$1[0] + 1 | 0];
                   if (List.mem(arg$5, symb)) {
-                    Caml_curry.app1(param[1], argv[current$1[0] + 1]);
-                    return ++ current$1[0];
+                    Caml_curry.app1(param[1], argv[current$1[0] + 1 | 0]);
+                    return current$1[0] = current$1[0] + 1 | 0;
                   }
                   else {
                     throw [
@@ -730,8 +730,8 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
             case 12 : 
                 var f = param[0];
                 while(current$1[0] < l - 1) {
-                  Caml_curry.app1(f, argv[current$1[0] + 1]);
-                  ++ current$1[0];
+                  Caml_curry.app1(f, argv[current$1[0] + 1 | 0]);
+                  current$1[0] = current$1[0] + 1 | 0;
                 };
                 return /* () */0;
             
@@ -755,7 +755,7 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
           throw exn$1;
         }
       }
-      ++ current$1[0];
+      current$1[0] = current$1[0] + 1 | 0;
     }
     else {
       try {
@@ -773,7 +773,7 @@ function parse_argv_dynamic($staropt$star, argv, speclist, anonfun, errmsg) {
           throw exn$2;
         }
       }
-      ++ current$1[0];
+      current$1[0] = current$1[0] + 1 | 0;
     }
   };
   return /* () */0;
@@ -872,7 +872,7 @@ function second_word(s) {
         return len;
       }
       else if (s[n] === " ") {
-        _n = n + 1;
+        _n = n + 1 | 0;
         continue ;
         
       }
@@ -897,7 +897,7 @@ function max_arg_len(cur, param) {
     return Pervasives.max(cur, kwd.length);
   }
   else {
-    return Pervasives.max(cur, kwd.length + second_word(param[2]));
+    return Pervasives.max(cur, kwd.length + second_word(param[2]) | 0);
   }
 }
 
@@ -917,7 +917,7 @@ function align($staropt$star, speclist) {
               else if (spec.tag === 11) {
                 var msg = ksd[2];
                 var cutcol = second_word(msg);
-                var n = Pervasives.max(0, len$2 - cutcol) + 3;
+                var n = Pervasives.max(0, len$2 - cutcol) + 3 | 0;
                 var spaces = Caml_string.bytes_to_string(Bytes.make(n, /* " " */32));
                 return /* tuple */[
                         kwd,
diff --git a/jscomp/stdlib/array.js b/jscomp/stdlib/array.js
index 20600af3a7..46198b4689 100644
--- a/jscomp/stdlib/array.js
+++ b/jscomp/stdlib/array.js
@@ -15,7 +15,7 @@ function init(l, f) {
     }
     else {
       var res = Caml_array.caml_make_vect(l, Caml_curry.app1(f, 0));
-      for(var i = 1 ,i_finish = l - 1; i<= i_finish; ++i){
+      for(var i = 1 ,i_finish = l - 1 | 0; i<= i_finish; ++i){
         res[i] = Caml_curry.app1(f, i);
       }
       return res;
@@ -28,7 +28,7 @@ function init(l, f) {
 
 function make_matrix(sx, sy, init) {
   var res = Caml_array.caml_make_vect(sx, /* array */[]);
-  for(var x = 0 ,x_finish = sx - 1; x<= x_finish; ++x){
+  for(var x = 0 ,x_finish = sx - 1 | 0; x<= x_finish; ++x){
     res[x] = Caml_array.caml_make_vect(sy, init);
   }
   return res;
@@ -79,7 +79,7 @@ function fill(a, ofs, len, v) {
         ];
   }
   else {
-    for(var i = ofs ,i_finish = ofs + len - 1; i<= i_finish; ++i){
+    for(var i = ofs ,i_finish = (ofs + len | 0) - 1; i<= i_finish; ++i){
       a[i] = v;
     }
     return /* () */0;
@@ -167,7 +167,7 @@ function list_length(_accu, _param) {
     var accu = _accu;
     if (param) {
       _param = param[1];
-      _accu = accu + 1;
+      _accu = accu + 1 | 0;
       continue ;
       
     }
@@ -188,7 +188,7 @@ function of_list(l) {
       if (param) {
         a[i] = param[0];
         _param = param[1];
-        _i = i + 1;
+        _i = i + 1 | 0;
         continue ;
         
       }
@@ -227,19 +227,19 @@ var Bottom = {
 
 function sort(cmp, a) {
   var maxson = function (l, i) {
-    var i31 = i + i + i + 1;
+    var i31 = ((i + i | 0) + i | 0) + 1 | 0;
     var x = i31;
-    if (i31 + 2 < l) {
-      if (Caml_curry.app2(cmp, a[i31], a[i31 + 1]) < 0) {
-        x = i31 + 1;
+    if ((i31 + 2 | 0) < l) {
+      if (Caml_curry.app2(cmp, a[i31], a[i31 + 1 | 0]) < 0) {
+        x = i31 + 1 | 0;
       }
-      if (Caml_curry.app2(cmp, a[x], a[i31 + 2]) < 0) {
-        x = i31 + 2;
+      if (Caml_curry.app2(cmp, a[x], a[i31 + 2 | 0]) < 0) {
+        x = i31 + 2 | 0;
       }
       return x;
     }
-    else if (i31 + 1 < l && Caml_curry.app2(cmp, a[i31], a[i31 + 1]) < 0) {
-      return i31 + 1;
+    else if ((i31 + 1 | 0) < l && Caml_curry.app2(cmp, a[i31], a[i31 + 1 | 0]) < 0) {
+      return i31 + 1 | 0;
     }
     else if (i31 < l) {
       return i31;
@@ -336,7 +336,7 @@ function sort(cmp, a) {
     };
   };
   var l = a.length;
-  for(var i = ((l + 1) / 3 | 0) - 1; i>= 0; --i){
+  for(var i = ((l + 1 | 0) / 3 | 0) - 1; i>= 0; --i){
     trickle(l, i, a[i]);
   }
   for(var i$1 = l - 1; i$1>= 2; --i$1){
@@ -357,8 +357,8 @@ function sort(cmp, a) {
 
 function stable_sort(cmp, a) {
   var merge = function (src1ofs, src1len, src2, src2ofs, src2len, dst, dstofs) {
-    var src1r = src1ofs + src1len;
-    var src2r = src2ofs + src2len;
+    var src1r = src1ofs + src1len | 0;
+    var src2r = src2ofs + src2len | 0;
     var _i1 = src1ofs;
     var _s1 = a[src1ofs];
     var _i2 = src2ofs;
@@ -372,43 +372,43 @@ function stable_sort(cmp, a) {
       var i1 = _i1;
       if (Caml_curry.app2(cmp, s1, s2) <= 0) {
         dst[d] = s1;
-        var i1$1 = i1 + 1;
+        var i1$1 = i1 + 1 | 0;
         if (i1$1 < src1r) {
-          _d = d + 1;
+          _d = d + 1 | 0;
           _s1 = a[i1$1];
           _i1 = i1$1;
           continue ;
           
         }
         else {
-          return blit(src2, i2, dst, d + 1, src2r - i2);
+          return blit(src2, i2, dst, d + 1 | 0, src2r - i2);
         }
       }
       else {
         dst[d] = s2;
-        var i2$1 = i2 + 1;
+        var i2$1 = i2 + 1 | 0;
         if (i2$1 < src2r) {
-          _d = d + 1;
+          _d = d + 1 | 0;
           _s2 = src2[i2$1];
           _i2 = i2$1;
           continue ;
           
         }
         else {
-          return blit(a, i1, dst, d + 1, src1r - i1);
+          return blit(a, i1, dst, d + 1 | 0, src1r - i1);
         }
       }
     };
   };
   var isortto = function (srcofs, dst, dstofs, len) {
     for(var i = 0 ,i_finish = len - 1; i<= i_finish; ++i){
-      var e = a[srcofs + i];
-      var j = dstofs + i - 1;
+      var e = a[srcofs + i | 0];
+      var j = (dstofs + i | 0) - 1;
       while(j >= dstofs && Caml_curry.app2(cmp, dst[j], e) > 0) {
-        dst[j + 1] = dst[j];
-        -- j;
+        dst[j + 1 | 0] = dst[j];
+        j = j - 1 | 0;
       };
-      dst[j + 1] = e;
+      dst[j + 1 | 0] = e;
     }
     return /* () */0;
   };
@@ -419,9 +419,9 @@ function stable_sort(cmp, a) {
     else {
       var l1 = len / 2 | 0;
       var l2 = len - l1;
-      sortto(srcofs + l1, dst, dstofs + l1, l2);
-      sortto(srcofs, a, srcofs + l2, l1);
-      return merge(srcofs + l2, l1, dst, dstofs + l1, l2, dst, dstofs);
+      sortto(srcofs + l1 | 0, dst, dstofs + l1 | 0, l2);
+      sortto(srcofs, a, srcofs + l2 | 0, l1);
+      return merge(srcofs + l2 | 0, l1, dst, dstofs + l1 | 0, l2, dst, dstofs);
     }
   };
   var l = a.length;
diff --git a/jscomp/stdlib/bigarray.js b/jscomp/stdlib/bigarray.js
index b6847d68aa..fe0203fec1 100644
--- a/jscomp/stdlib/bigarray.js
+++ b/jscomp/stdlib/bigarray.js
@@ -35,7 +35,7 @@ function of_array(kind, layout, data) {
   var ba = create(kind, layout, data.length);
   var ofs = layout !== 0 ? 1 : 0;
   for(var i = 0 ,i_finish = data.length - 1; i<= i_finish; ++i){
-    Caml_bigarray.caml_ba_set_1(ba, i + ofs, data[i]);
+    Caml_bigarray.caml_ba_set_1(ba, i + ofs | 0, data[i]);
   }
   return ba;
 }
@@ -79,7 +79,7 @@ function of_array$1(kind, layout, data) {
           ];
     }
     for(var j = 0 ,j_finish = dim2 - 1; j<= j_finish; ++j){
-      Caml_bigarray.caml_ba_set_2(ba, i + ofs, j + ofs, row[j]);
+      Caml_bigarray.caml_ba_set_2(ba, i + ofs | 0, j + ofs | 0, row[j]);
     }
   }
   return ba;
@@ -153,7 +153,7 @@ function of_array$2(kind, layout, data) {
             ];
       }
       for(var k = 0 ,k_finish = dim3 - 1; k<= k_finish; ++k){
-        Caml_bigarray.caml_ba_set_3(ba, i + ofs, j + ofs, k + ofs, col[k]);
+        Caml_bigarray.caml_ba_set_3(ba, i + ofs | 0, j + ofs | 0, k + ofs | 0, col[k]);
       }
     }
   }
diff --git a/jscomp/stdlib/buffer.js b/jscomp/stdlib/buffer.js
index b1282759c3..e29b871eac 100644
--- a/jscomp/stdlib/buffer.js
+++ b/jscomp/stdlib/buffer.js
@@ -84,11 +84,11 @@ function reset(b) {
 function resize(b, more) {
   var len = b[/* length */2];
   var new_len = len;
-  while(b[/* position */1] + more > new_len) {
-    new_len = 2 * new_len;
+  while((b[/* position */1] + more | 0) > new_len) {
+    new_len = (new_len << 1);
   };
   if (new_len > Sys.max_string_length) {
-    if (b[/* position */1] + more <= Sys.max_string_length) {
+    if ((b[/* position */1] + more | 0) <= Sys.max_string_length) {
       new_len = Sys.max_string_length;
     }
     else {
@@ -111,18 +111,18 @@ function add_char(b, c) {
     resize(b, 1);
   }
   b[/* buffer */0][pos] = c;
-  b[/* position */1] = pos + 1;
+  b[/* position */1] = pos + 1 | 0;
   return /* () */0;
 }
 
 function add_substring(b, s, offset, len) {
-  if (offset < 0 || len < 0 || offset + len > s.length) {
+  if (offset < 0 || len < 0 || (offset + len | 0) > s.length) {
     throw [
           Caml_builtin_exceptions.invalid_argument,
           "Buffer.add_substring/add_subbytes"
         ];
   }
-  var new_position = b[/* position */1] + len;
+  var new_position = b[/* position */1] + len | 0;
   if (new_position > b[/* length */2]) {
     resize(b, len);
   }
@@ -137,7 +137,7 @@ function add_subbytes(b, s, offset, len) {
 
 function add_string(b, s) {
   var len = s.length;
-  var new_position = b[/* position */1] + len;
+  var new_position = b[/* position */1] + len | 0;
   if (new_position > b[/* length */2]) {
     resize(b, len);
   }
@@ -161,11 +161,11 @@ function add_channel(b, ic, len) {
           "Buffer.add_channel"
         ];
   }
-  if (b[/* position */1] + len > b[/* length */2]) {
+  if ((b[/* position */1] + len | 0) > b[/* length */2]) {
     resize(b, len);
   }
   Pervasives.really_input(ic, b[/* buffer */0], b[/* position */1], len);
-  b[1] += len;
+  b[/* position */1] = b[/* position */1] + len | 0;
   return /* () */0;
 }
 
@@ -205,14 +205,14 @@ function advance_to_closing(opening, closing, k, s, start) {
       throw Caml_builtin_exceptions.not_found;
     }
     else if (s.charCodeAt(i) === opening) {
-      _i = i + 1;
-      _k = k$1 + 1;
+      _i = i + 1 | 0;
+      _k = k$1 + 1 | 0;
       continue ;
       
     }
     else if (s.charCodeAt(i) === closing) {
       if (k$1) {
-        _i = i + 1;
+        _i = i + 1 | 0;
         _k = k$1 - 1;
         continue ;
         
@@ -222,7 +222,7 @@ function advance_to_closing(opening, closing, k, s, start) {
       }
     }
     else {
-      _i = i + 1;
+      _i = i + 1 | 0;
       continue ;
       
     }
@@ -271,7 +271,7 @@ function advance_to_non_alpha(s, start) {
         return i;
       }
       if (exit === 1) {
-        _i = i + 1;
+        _i = i + 1 | 0;
         continue ;
         
       }
@@ -289,7 +289,7 @@ function find_ident(s, start, lim) {
     var exit = 0;
     if (c !== 40) {
       if (c !== 123) {
-        var stop = advance_to_non_alpha(s, start + 1);
+        var stop = advance_to_non_alpha(s, start + 1 | 0);
         return /* tuple */[
                 $$String.sub(s, start, stop - start),
                 stop
@@ -303,11 +303,11 @@ function find_ident(s, start, lim) {
       exit = 1;
     }
     if (exit === 1) {
-      var new_start = start + 1;
+      var new_start = start + 1 | 0;
       var stop$1 = advance_to_closing(c, closing(c), 0, s, new_start);
       return /* tuple */[
               $$String.sub(s, new_start, stop$1 - start - 1),
-              stop$1 + 1
+              stop$1 + 1 | 0
             ];
     }
     
@@ -327,20 +327,20 @@ function add_substitute(b, f, s) {
         if (previous === /* "\\" */92) {
           add_char(b, /* "\\" */92);
           add_char(b, current);
-          _i = i + 1;
+          _i = i + 1 | 0;
           _previous = /* " " */32;
           continue ;
           
         }
         else if (current !== 92) {
           add_char(b, current);
-          _i = i + 1;
+          _i = i + 1 | 0;
           _previous = current;
           continue ;
           
         }
         else {
-          _i = i + 1;
+          _i = i + 1 | 0;
           _previous = current;
           continue ;
           
@@ -348,13 +348,13 @@ function add_substitute(b, f, s) {
       }
       else if (previous === /* "\\" */92) {
         add_char(b, current);
-        _i = i + 1;
+        _i = i + 1 | 0;
         _previous = /* " " */32;
         continue ;
         
       }
       else {
-        var j = i + 1;
+        var j = i + 1 | 0;
         var match = find_ident(s, j, lim);
         add_string(b, Caml_curry.app1(f, match[0]));
         _i = match[1];
diff --git a/jscomp/stdlib/bytes.js b/jscomp/stdlib/bytes.js
index ae99a53f32..ff83127726 100644
--- a/jscomp/stdlib/bytes.js
+++ b/jscomp/stdlib/bytes.js
@@ -5,6 +5,7 @@ var Caml_builtin_exceptions = require("../runtime/caml_builtin_exceptions");
 var Caml_obj                = require("../runtime/caml_obj");
 var Pervasives              = require("./pervasives");
 var Char                    = require("./char");
+var Caml_primitive          = require("../runtime/caml_primitive");
 var Caml_curry              = require("../runtime/caml_curry");
 var Caml_string             = require("../runtime/caml_string");
 var List                    = require("./list");
@@ -59,7 +60,7 @@ function sub_string(b, ofs, len) {
 }
 
 function extend(s, left, right) {
-  var len = s.length + left + right;
+  var len = (s.length + left | 0) + right | 0;
   var r = Caml_string.caml_create_string(len);
   var match = left < 0 ? /* tuple */[
       -left,
@@ -133,18 +134,18 @@ function concat(sep, l) {
     var num = [0];
     var len = [0];
     List.iter(function (s) {
-          ++ num[0];
-          len[0] += s.length;
+          num[0] = num[0] + 1 | 0;
+          len[0] = len[0] + s.length | 0;
           return /* () */0;
         }, l);
-    var r = Caml_string.caml_create_string(len[0] + sep.length * (num[0] - 1));
+    var r = Caml_string.caml_create_string(len[0] + Caml_primitive.imul(sep.length, num[0] - 1) | 0);
     Caml_string.caml_blit_bytes(hd, 0, r, 0, hd.length);
     var pos = [hd.length];
     List.iter(function (s) {
           Caml_string.caml_blit_bytes(sep, 0, r, pos[0], sep.length);
-          pos[0] += sep.length;
+          pos[0] = pos[0] + sep.length | 0;
           Caml_string.caml_blit_bytes(s, 0, r, pos[0], s.length);
-          pos[0] += s.length;
+          pos[0] = pos[0] + s.length | 0;
           return /* () */0;
         }, l[1]);
     return r;
@@ -159,7 +160,7 @@ function cat(a, b) {
 }
 
 function is_space(param) {
-  var switcher = param - 9;
+  var switcher = param - 9 | 0;
   if (switcher > 4 || switcher < 0) {
     if (switcher !== 23) {
       return /* false */0;
@@ -180,14 +181,14 @@ function trim(s) {
   var len = s.length;
   var i = 0;
   while(i < len && is_space(s[i])) {
-    ++ i;
+    i = i + 1 | 0;
   };
   var j = len - 1;
   while(j >= i && is_space(s[j])) {
-    -- j;
+    j = j - 1 | 0;
   };
   if (j >= i) {
-    return sub(s, i, j - i + 1);
+    return sub(s, i, j - i + 1 | 0);
   }
   else {
     return empty;
@@ -225,7 +226,7 @@ function escaped(s) {
     if (exit === 1) {
       $js = Caml_string.caml_is_printable(c) ? 1 : 4;
     }
-    n += $js;
+    n = n + $js | 0;
   }
   if (n === s.length) {
     return copy(s);
@@ -236,26 +237,26 @@ function escaped(s) {
     for(var i$1 = 0 ,i_finish$1 = s.length - 1; i$1<= i_finish$1; ++i$1){
       var c$1 = s[i$1];
       var exit$1 = 0;
-      var switcher = c$1 - 34;
+      var switcher = c$1 - 34 | 0;
       if (switcher > 58 || switcher < 0) {
         if (switcher >= -20) {
           exit$1 = 1;
         }
         else {
-          switch (switcher + 34) {
+          switch (switcher + 34 | 0) {
             case 8 : 
                 s$prime[n] = /* "\\" */92;
-                ++ n;
+                n = n + 1 | 0;
                 s$prime[n] = /* "b" */98;
                 break;
             case 9 : 
                 s$prime[n] = /* "\\" */92;
-                ++ n;
+                n = n + 1 | 0;
                 s$prime[n] = /* "t" */116;
                 break;
             case 10 : 
                 s$prime[n] = /* "\\" */92;
-                ++ n;
+                n = n + 1 | 0;
                 s$prime[n] = /* "n" */110;
                 break;
             case 0 : 
@@ -272,7 +273,7 @@ function escaped(s) {
                 break;
             case 13 : 
                 s$prime[n] = /* "\\" */92;
-                ++ n;
+                n = n + 1 | 0;
                 s$prime[n] = /* "r" */114;
                 break;
             
@@ -281,7 +282,7 @@ function escaped(s) {
       }
       else if (switcher > 57 || switcher < 1) {
         s$prime[n] = /* "\\" */92;
-        ++ n;
+        n = n + 1 | 0;
         s$prime[n] = c$1;
       }
       else {
@@ -293,15 +294,15 @@ function escaped(s) {
         }
         else {
           s$prime[n] = /* "\\" */92;
-          ++ n;
-          s$prime[n] = 48 + (c$1 / 100 | 0);
-          ++ n;
-          s$prime[n] = 48 + (c$1 / 10 | 0) % 10;
-          ++ n;
-          s$prime[n] = 48 + c$1 % 10;
+          n = n + 1 | 0;
+          s$prime[n] = 48 + (c$1 / 100 | 0) | 0;
+          n = n + 1 | 0;
+          s$prime[n] = 48 + (c$1 / 10 | 0) % 10 | 0;
+          n = n + 1 | 0;
+          s$prime[n] = 48 + c$1 % 10 | 0;
         }
       }
-      ++ n;
+      n = n + 1 | 0;
     }
     return s$prime;
   }
@@ -372,7 +373,7 @@ function index_rec(s, lim, _i, c) {
       return i;
     }
     else {
-      _i = i + 1;
+      _i = i + 1 | 0;
       continue ;
       
     }
diff --git a/jscomp/stdlib/camlinternalFormat.js b/jscomp/stdlib/camlinternalFormat.js
index 7ec4571709..e3113869ea 100644
--- a/jscomp/stdlib/camlinternalFormat.js
+++ b/jscomp/stdlib/camlinternalFormat.js
@@ -10,6 +10,7 @@ var Pervasives               = require("./pervasives");
 var Caml_format              = require("../runtime/caml_format");
 var Char                     = require("./char");
 var Sys                      = require("./sys");
+var Caml_primitive           = require("../runtime/caml_primitive");
 var CamlinternalFormatBasics = require("./camlinternalFormatBasics");
 var Buffer                   = require("./buffer");
 var $$String                 = require("./string");
@@ -271,9 +272,9 @@ function param_format_of_ignored_format(ign, fmt) {
 
 function buffer_check_size(buf, overhead) {
   var len = buf[/* bytes */1].length;
-  var min_len = buf[/* ind */0] + overhead;
+  var min_len = buf[/* ind */0] + overhead | 0;
   if (min_len > len) {
-    var new_len = Pervasives.max(len * 2, min_len);
+    var new_len = Pervasives.max((len << 1), min_len);
     var new_str = Caml_string.caml_create_string(new_len);
     Bytes.blit(buf[/* bytes */1], 0, new_str, 0, len);
     buf[/* bytes */1] = new_str;
@@ -287,7 +288,7 @@ function buffer_check_size(buf, overhead) {
 function buffer_add_char(buf, c) {
   buffer_check_size(buf, 1);
   buf[/* bytes */1][buf[/* ind */0]] = c;
-  ++ buf[0];
+  buf[/* ind */0] = buf[/* ind */0] + 1 | 0;
   return /* () */0;
 }
 
@@ -295,7 +296,7 @@ function buffer_add_string(buf, s) {
   var str_len = s.length;
   buffer_check_size(buf, str_len);
   $$String.blit(s, 0, buf[/* bytes */1], buf[/* ind */0], str_len);
-  buf[0] += str_len;
+  buf[/* ind */0] = buf[/* ind */0] + str_len | 0;
   return /* () */0;
 }
 
@@ -372,7 +373,7 @@ function bprint_char_set(buf, char_set) {
   var print_start = function (set) {
     var is_alone = function (c) {
       var match_000 = Char.chr(c - 1);
-      var match_001 = Char.chr(c + 1);
+      var match_001 = Char.chr(c + 1 | 0);
       if (is_in_char_set(set, c)) {
         return !(is_in_char_set(set, match_000) && is_in_char_set(set, match_001));
       }
@@ -399,24 +400,24 @@ function bprint_char_set(buf, char_set) {
           var set$1 = set;
           var i$1 = i;
           var match = Pervasives.char_of_int(i$1);
-          var switcher = match - 45;
+          var switcher = match - 45 | 0;
           if (switcher > 48 || switcher < 0) {
             if (switcher >= 210) {
               return print_char(buf, 255);
             }
             else {
-              return print_second(set$1, i$1 + 1);
+              return print_second(set$1, i$1 + 1 | 0);
             }
           }
           else if (switcher > 47 || switcher < 1) {
-            return print_out(set$1, i$1 + 1);
+            return print_out(set$1, i$1 + 1 | 0);
           }
           else {
-            return print_second(set$1, i$1 + 1);
+            return print_second(set$1, i$1 + 1 | 0);
           }
         }
         else {
-          _i = i + 1;
+          _i = i + 1 | 0;
           continue ;
           
         }
@@ -430,7 +431,7 @@ function bprint_char_set(buf, char_set) {
     if (is_in_char_set(set, Pervasives.char_of_int(i))) {
       var match = Pervasives.char_of_int(i);
       var exit = 0;
-      var switcher = match - 45;
+      var switcher = match - 45 | 0;
       if (switcher > 48 || switcher < 0) {
         if (switcher >= 210) {
           print_char(buf, 254);
@@ -441,22 +442,22 @@ function bprint_char_set(buf, char_set) {
         }
       }
       else if (switcher > 47 || switcher < 1) {
-        if (is_in_char_set(set, Pervasives.char_of_int(i + 1))) {
+        if (is_in_char_set(set, Pervasives.char_of_int(i + 1 | 0))) {
           exit = 1;
         }
         else {
           print_char(buf, i - 1);
-          return print_out(set, i + 1);
+          return print_out(set, i + 1 | 0);
         }
       }
       else {
         exit = 1;
       }
       if (exit === 1) {
-        if (is_in_char_set(set, Pervasives.char_of_int(i + 1))) {
+        if (is_in_char_set(set, Pervasives.char_of_int(i + 1 | 0))) {
           var set$1 = set;
           var i$1 = i - 1;
-          var _j = i + 2;
+          var _j = i + 2 | 0;
           while(true) {
             var j = _j;
             if (j === 256 || !is_in_char_set(set$1, Pervasives.char_of_int(j))) {
@@ -464,14 +465,14 @@ function bprint_char_set(buf, char_set) {
               print_char(buf, /* "-" */45);
               print_char(buf, j - 1);
               if (j < 256) {
-                return print_out(set$1, j + 1);
+                return print_out(set$1, j + 1 | 0);
               }
               else {
                 return 0;
               }
             }
             else {
-              _j = j + 1;
+              _j = j + 1 | 0;
               continue ;
               
             }
@@ -480,14 +481,14 @@ function bprint_char_set(buf, char_set) {
         else {
           print_char(buf, i - 1);
           print_char(buf, i);
-          return print_out(set, i + 2);
+          return print_out(set, i + 2 | 0);
         }
       }
       
     }
     else {
       print_char(buf, i - 1);
-      return print_out(set, i + 1);
+      return print_out(set, i + 1 | 0);
     }
   };
   var print_char = function (buf, i) {
@@ -779,7 +780,7 @@ function bprint_fmtty(buf, _fmtty) {
 
 function int_of_custom_arity(param) {
   if (param) {
-    return 1 + int_of_custom_arity(param[0]);
+    return 1 + int_of_custom_arity(param[0]) | 0;
   }
   else {
     return 0;
@@ -3427,11 +3428,11 @@ function fix_padding(padty, width, str) {
       case 2 : 
           if (len > 0 && (str[0] === "+" || str[0] === "-" || str[0] === " ")) {
             res[0] = str.charCodeAt(0);
-            $$String.blit(str, 1, res, width$1 - len + 1, len - 1);
+            $$String.blit(str, 1, res, width$1 - len + 1 | 0, len - 1);
           }
           else if (len > 1 && str[0] === "0" && (str[1] === "x" || str[1] === "X")) {
             res[1] = str.charCodeAt(1);
-            $$String.blit(str, 2, res, width$1 - len + 2, len - 2);
+            $$String.blit(str, 2, res, width$1 - len + 2 | 0, len - 2);
           }
           else {
             $$String.blit(str, 0, res, width$1 - len, len);
@@ -3466,7 +3467,7 @@ function fix_int_precision(prec, str) {
   }
   else if (c !== 32) {
     if (c >= 43) {
-      switch (c - 43) {
+      switch (c - 43 | 0) {
         case 0 : 
         case 2 : 
             exit = 1;
@@ -3476,10 +3477,10 @@ function fix_int_precision(prec, str) {
         case 4 : 
             return str;
         case 5 : 
-            if (prec$1 + 2 > len && len > 1 && (str[1] === "x" || str[1] === "X")) {
-              var res = Bytes.make(prec$1 + 2, /* "0" */48);
+            if ((prec$1 + 2 | 0) > len && len > 1 && (str[1] === "x" || str[1] === "X")) {
+              var res = Bytes.make(prec$1 + 2 | 0, /* "0" */48);
               res[1] = str.charCodeAt(1);
-              $$String.blit(str, 2, res, prec$1 - len + 4, len - 2);
+              $$String.blit(str, 2, res, prec$1 - len + 4 | 0, len - 2);
               return Caml_string.bytes_to_string(res);
             }
             else {
@@ -3509,10 +3510,10 @@ function fix_int_precision(prec, str) {
   }
   switch (exit) {
     case 1 : 
-        if (prec$1 + 1 > len) {
-          var res$1 = Bytes.make(prec$1 + 1, /* "0" */48);
+        if ((prec$1 + 1 | 0) > len) {
+          var res$1 = Bytes.make(prec$1 + 1 | 0, /* "0" */48);
           res$1[0] = c;
-          $$String.blit(str, 1, res$1, prec$1 - len + 2, len - 1);
+          $$String.blit(str, 1, res$1, prec$1 - len + 2 | 0, len - 1);
           return Caml_string.bytes_to_string(res$1);
         }
         else {
@@ -3752,10 +3753,10 @@ function convert_float(fconv, prec, x) {
         }
         else {
           var match = str.charCodeAt(i);
-          var switcher = match - 46;
+          var switcher = match - 46 | 0;
           if (switcher > 23 || switcher < 0) {
             if (switcher !== 55) {
-              _i = i + 1;
+              _i = i + 1 | 0;
               continue ;
               
             }
@@ -3767,7 +3768,7 @@ function convert_float(fconv, prec, x) {
             return /* true */1;
           }
           else {
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             
           }
@@ -4782,13 +4783,13 @@ function open_box_of_string(str) {
               return i;
             }
             else {
-              _i = i + 1;
+              _i = i + 1 | 0;
               continue ;
               
             }
           }
           else {
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             
           }
@@ -4807,7 +4808,7 @@ function open_box_of_string(str) {
             return j;
           }
           else {
-            _j = j + 1;
+            _j = j + 1 | 0;
             continue ;
             
           }
@@ -4827,7 +4828,7 @@ function open_box_of_string(str) {
               return j;
             }
             else {
-              _j = j + 1;
+              _j = j + 1 | 0;
               continue ;
               
             }
@@ -4836,7 +4837,7 @@ function open_box_of_string(str) {
             return j;
           }
           else {
-            _j = j + 1;
+            _j = j + 1 | 0;
             continue ;
             
           }
@@ -5158,12 +5159,12 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         var match = str.charCodeAt(str_ind);
         if (match !== 37) {
           if (match !== 64) {
-            _str_ind = str_ind + 1;
+            _str_ind = str_ind + 1 | 0;
             continue ;
             
           }
           else {
-            var match$1 = parse_after_at(str_ind + 1, end_ind);
+            var match$1 = parse_after_at(str_ind + 1 | 0, end_ind);
             return add_literal(lit_start, str_ind, match$1[0]);
           }
         }
@@ -5176,7 +5177,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
   };
   var parse_format = function (pct_ind, end_ind) {
     var pct_ind$1 = pct_ind;
-    var str_ind = pct_ind + 1;
+    var str_ind = pct_ind + 1 | 0;
     var end_ind$1 = end_ind;
     if (str_ind === end_ind$1) {
       invalid_format_message(end_ind$1, "unexpected end of format");
@@ -5186,7 +5187,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
       return parse_flags(pct_ind$1, str_ind, end_ind$1, /* false */0);
     }
     else {
-      return parse_flags(pct_ind$1, str_ind + 1, end_ind$1, /* true */1);
+      return parse_flags(pct_ind$1, str_ind + 1 | 0, end_ind$1, /* true */1);
     }
   };
   var parse_flags = function (pct_ind, str_ind, end_ind, ign) {
@@ -5246,7 +5247,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
       }
       var match = str.charCodeAt(str_ind$1);
       var exit = 0;
-      var switcher = match - 32;
+      var switcher = match - 32 | 0;
       if (switcher > 16 || switcher < 0) {
         exit = 1;
       }
@@ -5254,19 +5255,19 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         switch (switcher) {
           case 0 : 
               set_flag(str_ind$1, space);
-              _str_ind = str_ind$1 + 1;
+              _str_ind = str_ind$1 + 1 | 0;
               continue ;
               case 3 : 
               set_flag(str_ind$1, sharp);
-              _str_ind = str_ind$1 + 1;
+              _str_ind = str_ind$1 + 1 | 0;
               continue ;
               case 11 : 
               set_flag(str_ind$1, plus);
-              _str_ind = str_ind$1 + 1;
+              _str_ind = str_ind$1 + 1 | 0;
               continue ;
               case 13 : 
               set_flag(str_ind$1, minus);
-              _str_ind = str_ind$1 + 1;
+              _str_ind = str_ind$1 + 1 | 0;
               continue ;
               case 1 : 
           case 2 : 
@@ -5284,7 +5285,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
               break;
           case 16 : 
               set_flag(str_ind$1, zero);
-              _str_ind = str_ind$1 + 1;
+              _str_ind = str_ind$1 + 1 | 0;
               continue ;
               
         }
@@ -5329,7 +5330,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
           exit$1 = 1;
         }
         else {
-          return parse_after_padding(pct_ind$1, str_ind$2 + 1, end_ind$1, minus$1, plus$1, sharp$1, space$1, ign$1, /* Arg_padding */{
+          return parse_after_padding(pct_ind$1, str_ind$2 + 1 | 0, end_ind$1, minus$1, plus$1, sharp$1, space$1, ign$1, /* Arg_padding */{
                       0: padty,
                       length: 1,
                       tag: 1
@@ -5365,11 +5366,11 @@ function fmt_ebb_of_string(legacy_behavior, str) {
     }
     var symb = str.charCodeAt(str_ind);
     if (symb !== 46) {
-      return parse_conversion(pct_ind, str_ind + 1, end_ind, plus, sharp, space, ign, pad, /* No_precision */0, pad, symb);
+      return parse_conversion(pct_ind, str_ind + 1 | 0, end_ind, plus, sharp, space, ign, pad, /* No_precision */0, pad, symb);
     }
     else {
       var pct_ind$1 = pct_ind;
-      var str_ind$1 = str_ind + 1;
+      var str_ind$1 = str_ind + 1 | 0;
       var end_ind$1 = end_ind;
       var minus$1 = minus;
       var plus$1 = plus;
@@ -5400,9 +5401,9 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         }
       }
       else if (symb$1 >= 42) {
-        switch (symb$1 - 42) {
+        switch (symb$1 - 42 | 0) {
           case 0 : 
-              return parse_after_precision(pct_ind$1, str_ind$1 + 1, end_ind$1, minus$1, plus$1, sharp$1, space$1, ign$1, pad$1, /* Arg_precision */1);
+              return parse_after_precision(pct_ind$1, str_ind$1 + 1 | 0, end_ind$1, minus$1, plus$1, sharp$1, space$1, ign$1, pad$1, /* Arg_precision */1);
           case 1 : 
           case 3 : 
               exit$1 = 2;
@@ -5420,7 +5421,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
       }
       if (exit$1 === 2) {
         if (legacy_behavior$1) {
-          return parse_literal(+(minus$1 || symb$1 === /* "-" */45), str_ind$1 + 1);
+          return parse_literal(+(minus$1 || symb$1 === /* "-" */45), str_ind$1 + 1 | 0);
         }
         else {
           exit = 1;
@@ -5446,7 +5447,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
       invalid_format_message(end_ind, "unexpected end of format");
     }
     var parse_conv = function (padprec) {
-      return parse_conversion(pct_ind, str_ind + 1, end_ind, plus, sharp, space, ign, pad, prec, padprec, str.charCodeAt(str_ind));
+      return parse_conversion(pct_ind, str_ind + 1 | 0, end_ind, plus, sharp, space, ign, pad, prec, padprec, str.charCodeAt(str_ind));
     };
     if (typeof pad === "number") {
       var exit = 0;
@@ -5612,7 +5613,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
             break;
         case 40 : 
             var sub_end = search_subformat_end(str_ind, end_ind, /* ")" */41);
-            var beg_ind = sub_end + 2;
+            var beg_ind = sub_end + 2 | 0;
             var match$1 = parse_literal(beg_ind, beg_ind, end_ind);
             var fmt_rest = match$1[0];
             var match$2 = parse_literal(str_ind, str_ind, sub_end);
@@ -6061,7 +6062,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         case 123 : 
             var sub_end$1 = search_subformat_end(str_ind, end_ind, /* "}" */125);
             var match$16 = parse_literal(str_ind, str_ind, sub_end$1);
-            var beg_ind$1 = sub_end$1 + 2;
+            var beg_ind$1 = sub_end$1 + 2 | 0;
             var match$17 = parse_literal(beg_ind$1, beg_ind$1, end_ind);
             var fmt_rest$8 = match$17[0];
             var sub_fmtty$1 = fmtty_of_fmt(match$16[0]);
@@ -6360,13 +6361,13 @@ function fmt_ebb_of_string(legacy_behavior, str) {
               exit = 1;
             }
             else {
-              switch (symb - 108) {
+              switch (symb - 108 | 0) {
                 case 0 : 
                     plus_used = /* true */1;
                     sharp_used = /* true */1;
                     space_used = /* true */1;
-                    var iconv$1 = compute_int_conv(pct_ind, str_ind + 1, plus, sharp, space, str.charCodeAt(str_ind));
-                    var beg_ind$2 = str_ind + 1;
+                    var iconv$1 = compute_int_conv(pct_ind, str_ind + 1 | 0, plus, sharp, space, str.charCodeAt(str_ind));
+                    var beg_ind$2 = str_ind + 1 | 0;
                     var match$25 = parse_literal(beg_ind$2, beg_ind$2, end_ind);
                     var fmt_rest$13 = match$25[0];
                     if (ign_used[0] = /* true */1, ign) {
@@ -6413,8 +6414,8 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                     plus_used = /* true */1;
                     sharp_used = /* true */1;
                     space_used = /* true */1;
-                    var iconv$2 = compute_int_conv(pct_ind, str_ind + 1, plus, sharp, space, str.charCodeAt(str_ind));
-                    var beg_ind$3 = str_ind + 1;
+                    var iconv$2 = compute_int_conv(pct_ind, str_ind + 1 | 0, plus, sharp, space, str.charCodeAt(str_ind));
+                    var beg_ind$3 = str_ind + 1 | 0;
                     var match$27 = parse_literal(beg_ind$3, beg_ind$3, end_ind);
                     var fmt_rest$14 = match$27[0];
                     if (ign_used[0] = /* true */1, ign) {
@@ -6465,8 +6466,8 @@ function fmt_ebb_of_string(legacy_behavior, str) {
             plus_used = /* true */1;
             sharp_used = /* true */1;
             space_used = /* true */1;
-            var iconv$3 = compute_int_conv(pct_ind, str_ind + 1, plus, sharp, space, str.charCodeAt(str_ind));
-            var beg_ind$4 = str_ind + 1;
+            var iconv$3 = compute_int_conv(pct_ind, str_ind + 1 | 0, plus, sharp, space, str.charCodeAt(str_ind));
+            var beg_ind$4 = str_ind + 1 | 0;
             var match$29 = parse_literal(beg_ind$4, beg_ind$4, end_ind);
             var fmt_rest$15 = match$29[0];
             if (ign_used[0] = /* true */1, ign) {
@@ -6651,19 +6652,19 @@ function fmt_ebb_of_string(legacy_behavior, str) {
       var exit = 0;
       if (c >= 65) {
         if (c >= 94) {
-          var switcher = c - 123;
+          var switcher = c - 123 | 0;
           if (switcher > 2 || switcher < 0) {
             exit = 1;
           }
           else {
             switch (switcher) {
               case 0 : 
-                  return parse_tag(/* true */1, str_ind + 1, end_ind);
+                  return parse_tag(/* true */1, str_ind + 1 | 0, end_ind);
               case 1 : 
                   exit = 1;
                   break;
               case 2 : 
-                  var beg_ind = str_ind + 1;
+                  var beg_ind = str_ind + 1 | 0;
                   var match = parse_literal(beg_ind, beg_ind, end_ind);
                   return /* Fmt_EBB */{
                           0: /* Formatting_lit */{
@@ -6680,14 +6681,14 @@ function fmt_ebb_of_string(legacy_behavior, str) {
           }
         }
         else if (c >= 91) {
-          switch (c - 91) {
+          switch (c - 91 | 0) {
             case 0 : 
-                return parse_tag(/* false */0, str_ind + 1, end_ind);
+                return parse_tag(/* false */0, str_ind + 1 | 0, end_ind);
             case 1 : 
                 exit = 1;
                 break;
             case 2 : 
-                var beg_ind$1 = str_ind + 1;
+                var beg_ind$1 = str_ind + 1 | 0;
                 var match$1 = parse_literal(beg_ind$1, beg_ind$1, end_ind);
                 return /* Fmt_EBB */{
                         0: /* Formatting_lit */{
@@ -6708,9 +6709,9 @@ function fmt_ebb_of_string(legacy_behavior, str) {
       }
       else if (c !== 10) {
         if (c >= 32) {
-          switch (c - 32) {
+          switch (c - 32 | 0) {
             case 0 : 
-                var beg_ind$2 = str_ind + 1;
+                var beg_ind$2 = str_ind + 1 | 0;
                 var match$2 = parse_literal(beg_ind$2, beg_ind$2, end_ind);
                 return /* Fmt_EBB */{
                         0: /* Formatting_lit */{
@@ -6729,8 +6730,8 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                         tag: 0
                       };
             case 5 : 
-                if (str_ind + 1 < end_ind && str[str_ind + 1] === "%") {
-                  var beg_ind$3 = str_ind + 2;
+                if ((str_ind + 1 | 0) < end_ind && str[str_ind + 1 | 0] === "%") {
+                  var beg_ind$3 = str_ind + 2 | 0;
                   var match$3 = parse_literal(beg_ind$3, beg_ind$3, end_ind);
                   return /* Fmt_EBB */{
                           0: /* Formatting_lit */{
@@ -6758,7 +6759,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                 }
                 break;
             case 12 : 
-                var beg_ind$4 = str_ind + 1;
+                var beg_ind$4 = str_ind + 1 | 0;
                 var match$5 = parse_literal(beg_ind$4, beg_ind$4, end_ind);
                 return /* Fmt_EBB */{
                         0: /* Formatting_lit */{
@@ -6777,7 +6778,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                         tag: 0
                       };
             case 14 : 
-                var beg_ind$5 = str_ind + 1;
+                var beg_ind$5 = str_ind + 1 | 0;
                 var match$6 = parse_literal(beg_ind$5, beg_ind$5, end_ind);
                 return /* Fmt_EBB */{
                         0: /* Formatting_lit */{
@@ -6790,14 +6791,14 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                         tag: 0
                       };
             case 27 : 
-                var str_ind$1 = str_ind + 1;
+                var str_ind$1 = str_ind + 1 | 0;
                 var end_ind$1 = end_ind;
                 var match$7;
                 try {
                   if (str_ind$1 === end_ind$1 || str.charCodeAt(str_ind$1) !== /* "<" */60) {
                     throw Caml_builtin_exceptions.not_found;
                   }
-                  var str_ind_1 = parse_spaces(str_ind$1 + 1, end_ind$1);
+                  var str_ind_1 = parse_spaces(str_ind$1 + 1 | 0, end_ind$1);
                   var match$8 = str.charCodeAt(str_ind_1);
                   var exit$1 = 0;
                   if (match$8 >= 48) {
@@ -6819,15 +6820,15 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                     var width = match$9[1];
                     var str_ind_3 = parse_spaces(match$9[0], end_ind$1);
                     var match$10 = str.charCodeAt(str_ind_3);
-                    var switcher$1 = match$10 - 45;
+                    var switcher$1 = match$10 - 45 | 0;
                     if (switcher$1 > 12 || switcher$1 < 0) {
                       if (switcher$1 !== 17) {
                         throw Caml_builtin_exceptions.not_found;
                       }
                       else {
-                        var s = $$String.sub(str, str_ind$1 - 2, str_ind_3 - str_ind$1 + 3);
+                        var s = $$String.sub(str, str_ind$1 - 2, str_ind_3 - str_ind$1 + 3 | 0);
                         match$7 = /* tuple */[
-                          str_ind_3 + 1,
+                          str_ind_3 + 1 | 0,
                           /* Break */{
                             0: s,
                             1: width,
@@ -6847,9 +6848,9 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                       if (str.charCodeAt(str_ind_5) !== /* ">" */62) {
                         throw Caml_builtin_exceptions.not_found;
                       }
-                      var s$1 = $$String.sub(str, str_ind$1 - 2, str_ind_5 - str_ind$1 + 3);
+                      var s$1 = $$String.sub(str, str_ind$1 - 2, str_ind_5 - str_ind$1 + 3 | 0);
                       match$7 = /* tuple */[
-                        str_ind_5 + 1,
+                        str_ind_5 + 1 | 0,
                         /* Break */{
                           0: s$1,
                           1: width,
@@ -6904,7 +6905,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                         tag: 0
                       };
             case 28 : 
-                var str_ind$2 = str_ind + 1;
+                var str_ind$2 = str_ind + 1 | 0;
                 var end_ind$2 = end_ind;
                 var match$13;
                 try {
@@ -6931,9 +6932,9 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                     if (str.charCodeAt(str_ind_3$1) !== /* ">" */62) {
                       throw Caml_builtin_exceptions.not_found;
                     }
-                    var s$2 = $$String.sub(str, str_ind$2 - 2, str_ind_3$1 - str_ind$2 + 3);
+                    var s$2 = $$String.sub(str, str_ind$2 - 2, str_ind_3$1 - str_ind$2 + 3 | 0);
                     match$13 = /* Some */[/* tuple */[
-                        str_ind_3$1 + 1,
+                        str_ind_3$1 + 1 | 0,
                         /* Magic_size */{
                           0: s$2,
                           1: match$15[1],
@@ -7015,7 +7016,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                 exit = 1;
                 break;
             case 31 : 
-                var beg_ind$6 = str_ind + 1;
+                var beg_ind$6 = str_ind + 1 | 0;
                 var match$19 = parse_literal(beg_ind$6, beg_ind$6, end_ind);
                 return /* Fmt_EBB */{
                         0: /* Formatting_lit */{
@@ -7028,7 +7029,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                         tag: 0
                       };
             case 32 : 
-                var beg_ind$7 = str_ind + 1;
+                var beg_ind$7 = str_ind + 1 | 0;
                 var match$20 = parse_literal(beg_ind$7, beg_ind$7, end_ind);
                 return /* Fmt_EBB */{
                         0: /* Formatting_lit */{
@@ -7048,7 +7049,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         }
       }
       else {
-        var beg_ind$8 = str_ind + 1;
+        var beg_ind$8 = str_ind + 1 | 0;
         var match$21 = parse_literal(beg_ind$8, beg_ind$8, end_ind);
         return /* Fmt_EBB */{
                 0: /* Formatting_lit */{
@@ -7062,7 +7063,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
               };
       }
       if (exit === 1) {
-        var beg_ind$9 = str_ind + 1;
+        var beg_ind$9 = str_ind + 1 | 0;
         var match$22 = parse_literal(beg_ind$9, beg_ind$9, end_ind);
         return /* Fmt_EBB */{
                 0: /* Formatting_lit */{
@@ -7118,14 +7119,14 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         throw Caml_builtin_exceptions.not_found;
       }
       else {
-        var ind = $$String.index_from(str, str_ind + 1, /* ">" */62);
+        var ind = $$String.index_from(str, str_ind + 1 | 0, /* ">" */62);
         if (ind >= end_ind) {
           throw Caml_builtin_exceptions.not_found;
         }
-        var sub_str = $$String.sub(str, str_ind, ind - str_ind + 1);
-        var beg_ind = ind + 1;
+        var sub_str = $$String.sub(str, str_ind, ind - str_ind + 1 | 0);
+        var beg_ind = ind + 1 | 0;
         var match$1 = parse_literal(beg_ind, beg_ind, end_ind);
-        var match$2 = parse_literal(str_ind, str_ind, ind + 1);
+        var match$2 = parse_literal(str_ind, str_ind, ind + 1 | 0);
         var sub_fmt = match$2[0];
         var sub_format = /* Format */{
           0: sub_fmt,
@@ -7264,7 +7265,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         invalid_format_message(end_ind, "unexpected end of format");
       }
       var c = str.charCodeAt(str_ind);
-      return parse_char_set_after_char(str_ind + 1, end_ind, c);
+      return parse_char_set_after_char(str_ind + 1 | 0, end_ind, c);
     };
     var parse_char_set_content = function (_str_ind, end_ind) {
       while(true) {
@@ -7275,15 +7276,15 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         var c = str.charCodeAt(str_ind);
         if (c !== 45) {
           if (c !== 93) {
-            return parse_char_set_after_char(str_ind + 1, end_ind, c);
+            return parse_char_set_after_char(str_ind + 1 | 0, end_ind, c);
           }
           else {
-            return str_ind + 1;
+            return str_ind + 1 | 0;
           }
         }
         else {
           add_in_char_set(char_set, /* "-" */45);
-          _str_ind = str_ind + 1;
+          _str_ind = str_ind + 1 | 0;
           continue ;
           
         }
@@ -7306,7 +7307,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
             }
             else {
               add_in_char_set(char_set, c);
-              return str_ind + 1;
+              return str_ind + 1 | 0;
             }
           }
           else {
@@ -7315,7 +7316,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         }
         else if (c$prime !== 37) {
           if (c$prime >= 45) {
-            var str_ind$1 = str_ind + 1;
+            var str_ind$1 = str_ind + 1 | 0;
             var end_ind$1 = end_ind;
             var c$1 = c;
             if (str_ind$1 === end_ind$1) {
@@ -7325,19 +7326,19 @@ function fmt_ebb_of_string(legacy_behavior, str) {
             if (c$prime$1 !== 37) {
               if (c$prime$1 !== 93) {
                 add_range(c$1, c$prime$1);
-                return parse_char_set_content(str_ind$1 + 1, end_ind$1);
+                return parse_char_set_content(str_ind$1 + 1 | 0, end_ind$1);
               }
               else {
                 add_in_char_set(char_set, c$1);
                 add_in_char_set(char_set, /* "-" */45);
-                return str_ind$1 + 1;
+                return str_ind$1 + 1 | 0;
               }
             }
             else {
-              if (str_ind$1 + 1 === end_ind$1) {
+              if ((str_ind$1 + 1 | 0) === end_ind$1) {
                 invalid_format_message(end_ind$1, "unexpected end of format");
               }
-              var c$prime$2 = str.charCodeAt(str_ind$1 + 1);
+              var c$prime$2 = str.charCodeAt(str_ind$1 + 1 | 0);
               var exit$2 = 0;
               if (c$prime$2 !== 37) {
                 if (c$prime$2 !== 64) {
@@ -7352,7 +7353,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
               }
               if (exit$2 === 1) {
                 add_range(c$1, c$prime$2);
-                return parse_char_set_content(str_ind$1 + 2, end_ind$1);
+                return parse_char_set_content(str_ind$1 + 2 | 0, end_ind$1);
               }
               
             }
@@ -7367,7 +7368,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         if (exit$1 === 2) {
           if (c === /* "%" */37) {
             add_in_char_set(char_set, c$prime);
-            return parse_char_set_content(str_ind + 1, end_ind);
+            return parse_char_set_content(str_ind + 1 | 0, end_ind);
           }
           else {
             exit = 1;
@@ -7379,7 +7380,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
           }
           add_in_char_set(char_set, c);
           _c = c$prime;
-          _str_ind = str_ind + 1;
+          _str_ind = str_ind + 1 | 0;
           continue ;
           
         }
@@ -7394,7 +7395,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         str_ind,
         /* false */0
       ] : /* tuple */[
-        str_ind + 1,
+        str_ind + 1 | 0,
         /* true */1
       ];
     var next_ind = parse_char_set_start(match$1[0], end_ind);
@@ -7411,7 +7412,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         invalid_format_message(end_ind, "unexpected end of format");
       }
       if (str[str_ind] === " ") {
-        _str_ind = str_ind + 1;
+        _str_ind = str_ind + 1 | 0;
         continue ;
         
       }
@@ -7435,7 +7436,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
               ];
       }
       else {
-        var new_acc = acc * 10 + (c - /* "0" */48);
+        var new_acc = Caml_primitive.imul(acc, 10) + (c - /* "0" */48) | 0;
         if (new_acc > Sys.max_string_length) {
           return Caml_curry.app3(failwith_message(/* Format */{
                           0: /* String_literal */{
@@ -7480,7 +7481,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         }
         else {
           _acc = new_acc;
-          _str_ind = str_ind + 1;
+          _str_ind = str_ind + 1 | 0;
           continue ;
           
         }
@@ -7518,15 +7519,15 @@ function fmt_ebb_of_string(legacy_behavior, str) {
           ];
     }
     else {
-      if (str_ind + 1 === end_ind) {
+      if ((str_ind + 1 | 0) === end_ind) {
         invalid_format_message(end_ind, "unexpected end of format");
       }
-      var c = str.charCodeAt(str_ind + 1);
+      var c = str.charCodeAt(str_ind + 1 | 0);
       if (c > 57 || c < 48) {
-        return expected_character(str_ind + 1, "digit", c);
+        return expected_character(str_ind + 1 | 0, "digit", c);
       }
       else {
-        var match$1 = parse_positive(str_ind + 1, end_ind, 0);
+        var match$1 = parse_positive(str_ind + 1 | 0, end_ind, 0);
         return /* tuple */[
                 match$1[0],
                 -match$1[1]
@@ -7619,19 +7620,19 @@ function fmt_ebb_of_string(legacy_behavior, str) {
       }
       var match = str.charCodeAt(str_ind);
       if (match !== 37) {
-        _str_ind = str_ind + 1;
+        _str_ind = str_ind + 1 | 0;
         continue ;
         
       }
       else {
-        if (str_ind + 1 === end_ind) {
+        if ((str_ind + 1 | 0) === end_ind) {
           invalid_format_message(end_ind, "unexpected end of format");
         }
-        if (str.charCodeAt(str_ind + 1) === c) {
+        if (str.charCodeAt(str_ind + 1 | 0) === c) {
           return str_ind;
         }
         else {
-          var match$1 = str.charCodeAt(str_ind + 1);
+          var match$1 = str.charCodeAt(str_ind + 1 | 0);
           var exit = 0;
           if (match$1 >= 95) {
             if (match$1 >= 123) {
@@ -7639,16 +7640,16 @@ function fmt_ebb_of_string(legacy_behavior, str) {
                 exit = 1;
               }
               else {
-                switch (match$1 - 123) {
+                switch (match$1 - 123 | 0) {
                   case 0 : 
-                      var sub_end = search_subformat_end(str_ind + 2, end_ind, /* "}" */125);
-                      _str_ind = sub_end + 2;
+                      var sub_end = search_subformat_end(str_ind + 2 | 0, end_ind, /* "}" */125);
+                      _str_ind = sub_end + 2 | 0;
                       continue ;
                       case 1 : 
                       exit = 1;
                       break;
                   case 2 : 
-                      return expected_character(str_ind + 1, "character ')'", /* "}" */125);
+                      return expected_character(str_ind + 1 | 0, "character ')'", /* "}" */125);
                   
                 }
               }
@@ -7657,26 +7658,26 @@ function fmt_ebb_of_string(legacy_behavior, str) {
               exit = 1;
             }
             else {
-              if (str_ind + 2 === end_ind) {
+              if ((str_ind + 2 | 0) === end_ind) {
                 invalid_format_message(end_ind, "unexpected end of format");
               }
-              var match$2 = str.charCodeAt(str_ind + 2);
+              var match$2 = str.charCodeAt(str_ind + 2 | 0);
               if (match$2 !== 40) {
                 if (match$2 !== 123) {
-                  _str_ind = str_ind + 3;
+                  _str_ind = str_ind + 3 | 0;
                   continue ;
                   
                 }
                 else {
-                  var sub_end$1 = search_subformat_end(str_ind + 3, end_ind, /* "}" */125);
-                  _str_ind = sub_end$1 + 2;
+                  var sub_end$1 = search_subformat_end(str_ind + 3 | 0, end_ind, /* "}" */125);
+                  _str_ind = sub_end$1 + 2 | 0;
                   continue ;
                   
                 }
               }
               else {
-                var sub_end$2 = search_subformat_end(str_ind + 3, end_ind, /* ")" */41);
-                _str_ind = sub_end$2 + 2;
+                var sub_end$2 = search_subformat_end(str_ind + 3 | 0, end_ind, /* ")" */41);
+                _str_ind = sub_end$2 + 2 | 0;
                 continue ;
                 
               }
@@ -7687,17 +7688,17 @@ function fmt_ebb_of_string(legacy_behavior, str) {
               exit = 1;
             }
             else {
-              return expected_character(str_ind + 1, "character '}'", /* ")" */41);
+              return expected_character(str_ind + 1 | 0, "character '}'", /* ")" */41);
             }
           }
           else {
-            var sub_end$3 = search_subformat_end(str_ind + 2, end_ind, /* ")" */41);
-            _str_ind = sub_end$3 + 2;
+            var sub_end$3 = search_subformat_end(str_ind + 2 | 0, end_ind, /* ")" */41);
+            _str_ind = sub_end$3 + 2 | 0;
             continue ;
             
           }
           if (exit === 1) {
-            _str_ind = str_ind + 2;
+            _str_ind = str_ind + 2 | 0;
             continue ;
             
           }
@@ -7707,7 +7708,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
     };
   };
   var is_int_base = function (symb) {
-    var switcher = symb - 88;
+    var switcher = symb - 88 | 0;
     if (switcher > 32 || switcher < 0) {
       return /* false */0;
     }
@@ -7759,7 +7760,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         exit = 1;
       }
       else {
-        switch (symb - 108) {
+        switch (symb - 108 | 0) {
           case 0 : 
               return /* Line_counter */0;
           case 1 : 
@@ -7850,7 +7851,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         }
       }
       else {
-        var switcher = symb - 88;
+        var switcher = symb - 88 | 0;
         if (switcher > 32 || switcher < 0) {
           exit = 1;
         }
@@ -7903,7 +7904,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
       }
       if (exit$1 === 2) {
         var exit$2 = 0;
-        var switcher$1 = symb - 88;
+        var switcher$1 = symb - 88 | 0;
         if (switcher$1 > 32 || switcher$1 < 0) {
           exit = 1;
         }
@@ -8045,7 +8046,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         else {
           var exit = 0;
           if (symb >= 72) {
-            var switcher = symb - 101;
+            var switcher = symb - 101 | 0;
             if (switcher > 2 || switcher < 0) {
               exit = 1;
             }
@@ -8062,7 +8063,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
             }
           }
           else if (symb >= 69) {
-            switch (symb - 69) {
+            switch (symb - 69 | 0) {
               case 0 : 
                   return /* Float_pE */7;
               case 1 : 
@@ -8092,7 +8093,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
       else if (space !== 0) {
         var exit$1 = 0;
         if (symb >= 72) {
-          var switcher$1 = symb - 101;
+          var switcher$1 = symb - 101 | 0;
           if (switcher$1 > 2 || switcher$1 < 0) {
             exit$1 = 1;
           }
@@ -8109,7 +8110,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
           }
         }
         else if (symb >= 69) {
-          switch (symb - 69) {
+          switch (symb - 69 | 0) {
             case 0 : 
                 return /* Float_sE */8;
             case 1 : 
@@ -8136,7 +8137,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         
       }
       else if (symb >= 72) {
-        var switcher$2 = symb - 101;
+        var switcher$2 = symb - 101 | 0;
         if (switcher$2 > 2 || switcher$2 < 0) {
           throw [
                 Caml_builtin_exceptions.assert_failure,
@@ -8160,7 +8161,7 @@ function fmt_ebb_of_string(legacy_behavior, str) {
         }
       }
       else if (symb >= 69) {
-        switch (symb - 69) {
+        switch (symb - 69 | 0) {
           case 0 : 
               return /* Float_E */6;
           case 1 : 
diff --git a/jscomp/stdlib/camlinternalOO.js b/jscomp/stdlib/camlinternalOO.js
index 5e0d5de923..afca9dd919 100644
--- a/jscomp/stdlib/camlinternalOO.js
+++ b/jscomp/stdlib/camlinternalOO.js
@@ -6,6 +6,7 @@ var Caml_obj                = require("../runtime/caml_obj");
 var Obj                     = require("./obj");
 var Caml_oo                 = require("../runtime/caml_oo");
 var Sys                     = require("./sys");
+var Caml_primitive          = require("../runtime/caml_primitive");
 var Caml_array              = require("../runtime/caml_array");
 var $$Array                 = require("./array");
 var Caml_curry              = require("../runtime/caml_curry");
@@ -27,7 +28,7 @@ var params = /* record */[
 function public_method_label(s) {
   var accu = 0;
   for(var i = 0 ,i_finish = s.length - 1; i<= i_finish; ++i){
-    accu = 223 * accu + s.charCodeAt(i);
+    accu = Caml_primitive.imul(223, accu) + s.charCodeAt(i) | 0;
   }
   accu = accu & (1 << 31) - 1;
   if (accu > 1073741823) {
@@ -55,7 +56,7 @@ function create(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -64,7 +65,7 @@ function create(l, x, d, r) {
 function bal(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -90,7 +91,7 @@ function bal(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -122,7 +123,7 @@ function bal(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -222,7 +223,7 @@ function create$1(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -231,7 +232,7 @@ function create$1(l, x, d, r) {
 function bal$1(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -257,7 +258,7 @@ function bal$1(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -289,7 +290,7 @@ function bal$1(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -353,7 +354,7 @@ function create$2(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -362,7 +363,7 @@ function create$2(l, x, d, r) {
 function bal$2(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -388,7 +389,7 @@ function bal$2(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -420,7 +421,7 @@ function bal$2(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -507,18 +508,18 @@ function fit_size(n) {
     return n;
   }
   else {
-    return fit_size((n + 1) / 2 | 0) * 2;
+    return (fit_size((n + 1 | 0) / 2 | 0) << 1);
   }
 }
 
 function new_table(pub_labels) {
-  ++ table_count[0];
+  table_count[0] = table_count[0] + 1 | 0;
   var len = pub_labels.length;
-  var methods = Caml_array.caml_make_vect(len * 2 + 2, dummy_met);
+  var methods = Caml_array.caml_make_vect((len << 1) + 2 | 0, dummy_met);
   methods[0] = len;
-  methods[1] = (fit_size(len) * Sys.word_size / 8 | 0) - 1;
+  methods[1] = (Caml_primitive.imul(fit_size(len), Sys.word_size) / 8 | 0) - 1;
   for(var i = 0 ,i_finish = len - 1; i<= i_finish; ++i){
-    methods[i * 2 + 3] = pub_labels[i];
+    methods[(i << 1) + 3 | 0] = pub_labels[i];
   }
   return /* record */[
           2,
@@ -551,7 +552,7 @@ var inst_var_count = [0];
 
 function new_method(table) {
   var index = table[/* methods */1].length;
-  resize(table, index + 1);
+  resize(table, index + 1 | 0);
   return index;
 }
 
@@ -597,12 +598,12 @@ function get_method_labels(table, names) {
 }
 
 function set_method(table, label, element) {
-  ++ method_count[0];
+  method_count[0] = method_count[0] + 1 | 0;
   if (find$1(label, table[/* methods_by_label */3])) {
     var array = table;
     var label$1 = label;
     var element$1 = element;
-    resize(array, label$1 + 1);
+    resize(array, label$1 + 1 | 0);
     array[/* methods */1][label$1] = element$1;
     return /* () */0;
   }
@@ -735,7 +736,7 @@ function widen(table) {
 
 function new_slot(table) {
   var index = table[/* size */0];
-  table[/* size */0] = index + 1;
+  table[/* size */0] = index + 1 | 0;
   return index;
 }
 
@@ -770,12 +771,12 @@ function new_methods_variables(table, meths, vals) {
   var meths$1 = to_array(meths);
   var nmeths = meths$1.length;
   var nvals = vals.length;
-  var res = Caml_array.caml_make_vect(nmeths + nvals, 0);
+  var res = Caml_array.caml_make_vect(nmeths + nvals | 0, 0);
   for(var i = 0 ,i_finish = nmeths - 1; i<= i_finish; ++i){
     res[i] = get_method_label(table, meths$1[i]);
   }
   for(var i$1 = 0 ,i_finish$1 = nvals - 1; i$1<= i_finish$1; ++i$1){
-    res[i$1 + nmeths] = new_variable(table, vals[i$1]);
+    res[i$1 + nmeths | 0] = new_variable(table, vals[i$1]);
   }
   return res;
 }
@@ -820,7 +821,7 @@ function create_table(public_methods) {
     var tags = $$Array.map(public_method_label, public_methods);
     var table = new_table(tags);
     $$Array.iteri(function (i, met) {
-          var lab = i * 2 + 2;
+          var lab = (i << 1) + 2 | 0;
           table[/* methods_by_name */2] = add$1(met, lab, table[/* methods_by_name */2]);
           table[/* methods_by_label */3] = add$2(lab, /* true */1, table[/* methods_by_label */3]);
           return /* () */0;
@@ -833,9 +834,9 @@ function create_table(public_methods) {
 }
 
 function init_class(table) {
-  inst_var_count[0] = inst_var_count[0] + table[/* size */0] - 1;
+  inst_var_count[0] = (inst_var_count[0] + table[/* size */0] | 0) - 1;
   table[/* initializers */7] = List.rev(table[/* initializers */7]);
-  return resize(table, 3 + (table[/* methods */1][1] * 16 / Sys.word_size | 0));
+  return resize(table, 3 + ((table[/* methods */1][1] << 4) / Sys.word_size | 0) | 0);
 }
 
 function inherits(cla, vals, virt_meths, concr_meths, param, top) {
@@ -1030,14 +1031,14 @@ function lookup_tables(root, keys) {
 
 function new_cache(table) {
   var n = new_method(table);
-  var n$1 = n % 2 === 0 || n > 2 + (table[/* methods */1][1] * 16 / Sys.word_size | 0) ? n : new_method(table);
+  var n$1 = n % 2 === 0 || n > (2 + ((table[/* methods */1][1] << 4) / Sys.word_size | 0) | 0) ? n : new_method(table);
   table[/* methods */1][n$1] = 0;
   return n$1;
 }
 
 function method_impl(table, i, arr) {
   var next = function () {
-    ++ i[0];
+    i[0] = i[0] + 1 | 0;
     return arr[i[0]];
   };
   var clo = next(/* () */0);
@@ -1260,7 +1261,7 @@ function set_methods(table, methods) {
     var label = methods[i[0]];
     var clo = method_impl(table, i, methods);
     set_method(table, label, clo);
-    ++ i[0];
+    i[0] = i[0] + 1 | 0;
   };
   return /* () */0;
 }
diff --git a/jscomp/stdlib/char.js b/jscomp/stdlib/char.js
index 461e393d09..90f02fdca0 100644
--- a/jscomp/stdlib/char.js
+++ b/jscomp/stdlib/char.js
@@ -64,9 +64,9 @@ function escaped(c) {
       var n = c;
       return Caml_string.caml_string_of_char_array(/* int array */[
                   /* "\\" */92,
-                  48 + (n / 100 | 0),
-                  48 + (n / 10 | 0) % 10,
-                  48 + n % 10
+                  48 + (n / 100 | 0) | 0,
+                  48 + (n / 10 | 0) % 10 | 0,
+                  48 + n % 10 | 0
                 ]);
     }
   }
@@ -75,7 +75,7 @@ function escaped(c) {
 
 function lowercase(c) {
   if (c >= /* "A" */65 && c <= /* "Z" */90 || c >= /* "\192" */192 && c <= /* "\214" */214 || c >= /* "\216" */216 && c <= /* "\222" */222) {
-    return c + 32;
+    return c + 32 | 0;
   }
   else {
     return c;
diff --git a/jscomp/stdlib/digest.js b/jscomp/stdlib/digest.js
index e75eaa0fb9..518185f480 100644
--- a/jscomp/stdlib/digest.js
+++ b/jscomp/stdlib/digest.js
@@ -62,15 +62,15 @@ function input(chan) {
 function char_hex(n) {
   return n + (
           n < 10 ? /* "0" */48 : 87
-        );
+        ) | 0;
 }
 
 function to_hex(d) {
   var result = new Array(32);
   for(var i = 0; i<= 15; ++i){
     var x = d.charCodeAt(i);
-    result[i * 2] = char_hex((x >>> 4));
-    result[i * 2 + 1] = char_hex(x & 15);
+    result[(i << 1)] = char_hex((x >>> 4));
+    result[(i << 1) + 1 | 0] = char_hex(x & 15);
   }
   return Caml_string.bytes_to_string(result);
 }
@@ -92,7 +92,7 @@ function from_hex(s) {
               ];
         }
         else {
-          return c - /* "a" */97 + 10;
+          return c - /* "a" */97 + 10 | 0;
         }
       }
       else if (c >= 71) {
@@ -102,7 +102,7 @@ function from_hex(s) {
             ];
       }
       else {
-        return c - /* "A" */65 + 10;
+        return c - /* "A" */65 + 10 | 0;
       }
     }
     else if (c > 57 || c < 48) {
@@ -116,11 +116,11 @@ function from_hex(s) {
     }
   };
   var $$byte = function (i) {
-    return (digit(s.charCodeAt(i)) << 4) + digit(s.charCodeAt(i + 1));
+    return (digit(s.charCodeAt(i)) << 4) + digit(s.charCodeAt(i + 1 | 0)) | 0;
   };
   var result = new Array(16);
   for(var i = 0; i<= 15; ++i){
-    result[i] = Char.chr($$byte(2 * i));
+    result[i] = Char.chr($$byte((i << 1)));
   }
   return Caml_string.bytes_to_string(result);
 }
diff --git a/jscomp/stdlib/filename.js b/jscomp/stdlib/filename.js
index 21baa8cb4e..8cbdf52d70 100644
--- a/jscomp/stdlib/filename.js
+++ b/jscomp/stdlib/filename.js
@@ -30,14 +30,14 @@ function generic_basename(is_dir_sep, current_dir_name, name) {
       }
       else {
         var _n$1 = n;
-        var p = n + 1;
+        var p = n + 1 | 0;
         while(true) {
           var n$1 = _n$1;
           if (n$1 < 0) {
             return $$String.sub(name, 0, p);
           }
           else if (Caml_curry.app2(is_dir_sep, name, n$1)) {
-            return $$String.sub(name, n$1 + 1, p - n$1 - 1);
+            return $$String.sub(name, n$1 + 1 | 0, p - n$1 - 1);
           }
           else {
             _n$1 = n$1 - 1;
@@ -86,7 +86,7 @@ function generic_dirname(is_dir_sep, current_dir_name, name) {
                 
               }
               else {
-                return $$String.sub(name, 0, n$2 + 1);
+                return $$String.sub(name, 0, n$2 + 1 | 0);
               }
             };
           }
@@ -157,7 +157,7 @@ function quote(param) {
   var quotequote = "'\\''";
   var s = param;
   var l = s.length;
-  var b = Buffer.create(l + 20);
+  var b = Buffer.create(l + 20 | 0);
   Buffer.add_char(b, /* "'" */39);
   for(var i = 0 ,i_finish = l - 1; i<= i_finish; ++i){
     if (s[i] === "'") {
@@ -322,7 +322,7 @@ function temp_file($staropt$star, prefix, suffix) {
           throw e;
         }
         else {
-          _counter = counter + 1;
+          _counter = counter + 1 | 0;
           continue ;
           
         }
@@ -365,7 +365,7 @@ function open_temp_file($staropt$star, $staropt$star$1, prefix, suffix) {
           throw e;
         }
         else {
-          _counter = counter + 1;
+          _counter = counter + 1 | 0;
           continue ;
           
         }
diff --git a/jscomp/stdlib/format.js b/jscomp/stdlib/format.js
index 2ff8ccafe6..76b1fe0f74 100644
--- a/jscomp/stdlib/format.js
+++ b/jscomp/stdlib/format.js
@@ -69,7 +69,7 @@ function take_queue(q) {
 }
 
 function pp_enqueue(state, token) {
-  state[12] += token[/* length */2];
+  state[/* pp_right_total */12] = state[/* pp_right_total */12] + token[/* length */2] | 0;
   return add_queue(token, state[/* pp_queue */26]);
 }
 
@@ -89,7 +89,7 @@ function pp_output_string(state, s) {
 function break_new_line(state, offset, width) {
   Caml_curry.app1(state[/* pp_out_newline */18], /* () */0);
   state[/* pp_is_new_line */10] = /* true */1;
-  var indent = state[/* pp_margin */5] - width + offset;
+  var indent = state[/* pp_margin */5] - width + offset | 0;
   var real_indent = Pervasives.min(state[/* pp_max_indent */7], indent);
   state[/* pp_current_indent */9] = real_indent;
   state[/* pp_space_left */8] = state[/* pp_margin */5] - state[/* pp_current_indent */9];
@@ -188,7 +188,7 @@ function format_pp_token(state, size, param) {
             var match$4 = take_queue(state$1[/* pp_queue */26]);
             var size$1 = match$4[/* elem_size */0];
             state$1[11] -= match$4[/* length */2];
-            state$1[8] += size$1;
+            state$1[/* pp_space_left */8] = state$1[/* pp_space_left */8] + size$1 | 0;
             return /* () */0;
           }
           else {
@@ -235,7 +235,7 @@ function format_pp_token(state, size, param) {
                     return break_same_line(state, n);
                   }
               case 4 : 
-                  if (state[/* pp_is_new_line */10] || !(size > state[/* pp_space_left */8] || state[/* pp_current_indent */9] > state[/* pp_margin */5] - width + off)) {
+                  if (state[/* pp_is_new_line */10] || !(size > state[/* pp_space_left */8] || state[/* pp_current_indent */9] > (state[/* pp_margin */5] - width + off | 0))) {
                     return break_same_line(state, n);
                   }
                   else {
@@ -295,10 +295,10 @@ function format_pp_token(state, size, param) {
             }
             var offset = tab - insertion_point;
             if (offset >= 0) {
-              return break_same_line(state, offset + param[0]);
+              return break_same_line(state, offset + param[0] | 0);
             }
             else {
-              return break_new_line(state, tab + param[1], state[/* pp_margin */5]);
+              return break_new_line(state, tab + param[1] | 0, state[/* pp_margin */5]);
             }
           }
           else {
@@ -357,7 +357,7 @@ function advance_left(state) {
       else {
         take_queue(state$1[/* pp_queue */26]);
         format_pp_token(state$1, size < 0 ? 1000000010 : size, match[/* token */1]);
-        state$1[/* pp_left_total */11] = match[/* length */2] + state$1[/* pp_left_total */11];
+        state$1[/* pp_left_total */11] = match[/* length */2] + state$1[/* pp_left_total */11] | 0;
         continue ;
         
       }
@@ -440,7 +440,7 @@ function set_size(state, ty) {
                 return 0;
               }
               else {
-                queue_elem[/* elem_size */0] = state[/* pp_right_total */12] + size;
+                queue_elem[/* elem_size */0] = state[/* pp_right_total */12] + size | 0;
                 state[/* pp_scan_stack */0] = t;
                 return /* () */0;
               }
@@ -450,7 +450,7 @@ function set_size(state, ty) {
       }
       if (exit === 1) {
         if (ty) {
-          queue_elem[/* elem_size */0] = state[/* pp_right_total */12] + size;
+          queue_elem[/* elem_size */0] = state[/* pp_right_total */12] + size | 0;
           state[/* pp_scan_stack */0] = t;
           return /* () */0;
         }
@@ -484,7 +484,7 @@ function scan_push(state, b, tok) {
 }
 
 function pp_open_box_gen(state, indent, br_ty) {
-  ++ state[13];
+  state[/* pp_curr_depth */13] = state[/* pp_curr_depth */13] + 1 | 0;
   if (state[/* pp_curr_depth */13] < state[/* pp_max_boxes */14]) {
     var elem = /* record */[
       -state[/* pp_right_total */12],
@@ -759,7 +759,7 @@ function pp_print_cut(state, _) {
 }
 
 function pp_open_tbox(state, _) {
-  ++ state[13];
+  state[/* pp_curr_depth */13] = state[/* pp_curr_depth */13] + 1 | 0;
   if (state[/* pp_curr_depth */13] < state[/* pp_max_boxes */14]) {
     var elem = /* record */[
       0,
@@ -871,7 +871,7 @@ function pp_print_text(ppf, s) {
   var right = [0];
   var flush = function () {
     pp_print_string(ppf, $$String.sub(s, left[0], right[0] - left[0]));
-    ++ right[0];
+    right[0] = right[0] + 1 | 0;
     left[0] = right[0];
     return /* () */0;
   };
@@ -879,7 +879,7 @@ function pp_print_text(ppf, s) {
     var match = s.charCodeAt(right[0]);
     if (match !== 10) {
       if (match !== 32) {
-        ++ right[0];
+        right[0] = right[0] + 1 | 0;
       }
       else {
         flush(/* () */0);
diff --git a/jscomp/stdlib/genlex.js b/jscomp/stdlib/genlex.js
index 8e1bdfdba0..7ea5aa77cb 100644
--- a/jscomp/stdlib/genlex.js
+++ b/jscomp/stdlib/genlex.js
@@ -7,6 +7,7 @@ var Hashtbl                 = require("./hashtbl");
 var Stream                  = require("./stream");
 var Caml_format             = require("../runtime/caml_format");
 var Char                    = require("./char");
+var Caml_primitive          = require("../runtime/caml_primitive");
 var Caml_string             = require("../runtime/caml_string");
 var List                    = require("./list");
 
@@ -24,12 +25,12 @@ function reset_buffer() {
 
 function store(c) {
   if (bufpos[0] >= buffer[0].length) {
-    var newbuffer = Caml_string.caml_create_string(2 * bufpos[0]);
+    var newbuffer = Caml_string.caml_create_string((bufpos[0] << 1));
     Bytes.blit(buffer[0], 0, newbuffer, 0, bufpos[0]);
     buffer[0] = newbuffer;
   }
   buffer[0][bufpos[0]] = c;
-  return ++ bufpos[0];
+  return bufpos[0] = bufpos[0] + 1 | 0;
 }
 
 function get_string() {
@@ -88,13 +89,13 @@ function make_lexer(keywords) {
         var c = match[0];
         var exit = 0;
         if (c < 124) {
-          var switcher = c - 65;
+          var switcher = c - 65 | 0;
           if (switcher > 57 || switcher < 0) {
             if (switcher >= 58) {
               exit = 1;
             }
             else {
-              switch (switcher + 65) {
+              switch (switcher + 65 | 0) {
                 case 9 : 
                 case 10 : 
                 case 12 : 
@@ -259,7 +260,7 @@ function make_lexer(keywords) {
             }
           }
           else {
-            var switcher$1 = switcher - 26;
+            var switcher$1 = switcher - 26 | 0;
             if (switcher$1 > 5 || switcher$1 < 0) {
               exit = 2;
             }
@@ -304,7 +305,7 @@ function make_lexer(keywords) {
                   var c$3 = match$4[0];
                   var exit$1 = 0;
                   if (c$3 >= 91) {
-                    var switcher$2 = c$3 - 95;
+                    var switcher$2 = c$3 - 95 | 0;
                     if (switcher$2 > 27 || switcher$2 < 0) {
                       if (switcher$2 >= 97) {
                         exit$1 = 1;
@@ -371,7 +372,7 @@ function make_lexer(keywords) {
         var c = match[0];
         var exit = 0;
         if (c >= 94) {
-          var switcher = c - 95;
+          var switcher = c - 95 | 0;
           if (switcher > 30 || switcher < 0) {
             if (switcher >= 32) {
               return /* Some */[ident_or_keyword(get_string(/* () */0))];
@@ -396,7 +397,7 @@ function make_lexer(keywords) {
           }
         }
         else if (c >= 33) {
-          switch (c - 33) {
+          switch (c - 33 | 0) {
             case 1 : 
             case 6 : 
             case 7 : 
@@ -494,7 +495,7 @@ function make_lexer(keywords) {
             var exit$1 = 0;
             if (match$1) {
               var c$1 = match$1[0];
-              var switcher = c$1 - 69;
+              var switcher = c$1 - 69 | 0;
               if (switcher > 32 || switcher < 0) {
                 if ((switcher + 21 >>> 0) > 9) {
                   exit$1 = 1;
@@ -673,7 +674,7 @@ function make_lexer(keywords) {
     if (match) {
       var c1 = match[0];
       if (c1 >= 58) {
-        var switcher = c1 - 110;
+        var switcher = c1 - 110 | 0;
         if (switcher > 6 || switcher < 0) {
           Stream.junk(strm__);
           return c1;
@@ -723,7 +724,7 @@ function make_lexer(keywords) {
               }
               else {
                 Stream.junk(strm__);
-                return Char.chr((c1 - 48) * 100 + (c2 - 48) * 10 + (c3 - 48));
+                return Char.chr((Caml_primitive.imul(c1 - 48, 100) + Caml_primitive.imul(c2 - 48, 10) | 0) + (c3 - 48) | 0);
               }
             }
             else {
@@ -754,7 +755,7 @@ function make_lexer(keywords) {
     while(true) {
       var match = Stream.peek(strm__);
       if (match) {
-        var switcher = match[0] - 40;
+        var switcher = match[0] - 40 | 0;
         if (switcher > 2 || switcher < 0) {
           Stream.junk(strm__);
           continue ;
diff --git a/jscomp/stdlib/hashtbl.js b/jscomp/stdlib/hashtbl.js
index 32a1ae2fca..c6ecd89442 100644
--- a/jscomp/stdlib/hashtbl.js
+++ b/jscomp/stdlib/hashtbl.js
@@ -74,11 +74,11 @@ function power_2_above(_x, n) {
     if (x >= n) {
       return x;
     }
-    else if (x * 2 > Sys.max_array_length) {
+    else if ((x << 1) > Sys.max_array_length) {
       return x;
     }
     else {
-      _x = x * 2;
+      _x = (x << 1);
       continue ;
       
     }
@@ -143,7 +143,7 @@ function length(h) {
 function resize(indexfun, h) {
   var odata = h[/* data */1];
   var osize = odata.length;
-  var nsize = osize * 2;
+  var nsize = (osize << 1);
   if (nsize < Sys.max_array_length) {
     var ndata = Caml_array.caml_make_vect(nsize, /* Empty */0);
     h[/* data */1] = ndata;
@@ -195,7 +195,7 @@ function add(h, key, info) {
     tag: 0
   };
   h[/* data */1][i] = bucket;
-  ++ h[0];
+  h[/* size */0] = h[/* size */0] + 1 | 0;
   if (h[/* size */0] > (h[/* data */1].length << 1)) {
     return resize(key_index, h);
   }
@@ -355,7 +355,7 @@ function replace(h, key, info) {
         length: 3,
         tag: 0
       };
-      ++ h[0];
+      h[/* size */0] = h[/* size */0] + 1 | 0;
       if (h[/* size */0] > (h[/* data */1].length << 1)) {
         return resize(key_index, h);
       }
@@ -441,7 +441,7 @@ function bucket_length(_accu, _param) {
     var accu = _accu;
     if (param) {
       _param = param[2];
-      _accu = accu + 1;
+      _accu = accu + 1 | 0;
       continue ;
       
     }
@@ -455,10 +455,10 @@ function stats(h) {
   var mbl = $$Array.fold_left(function (m, b) {
         return Pervasives.max(m, bucket_length(0, b));
       }, 0, h[/* data */1]);
-  var histo = Caml_array.caml_make_vect(mbl + 1, 0);
+  var histo = Caml_array.caml_make_vect(mbl + 1 | 0, 0);
   $$Array.iter(function (b) {
         var l = bucket_length(0, b);
-        histo[l] = histo[l] + 1;
+        histo[l] = histo[l] + 1 | 0;
         return /* () */0;
       }, h[/* data */1]);
   return /* record */[
@@ -484,7 +484,7 @@ function MakeSeeded(H) {
       tag: 0
     };
     h[/* data */1][i] = bucket;
-    ++ h[0];
+    h[/* size */0] = h[/* size */0] + 1 | 0;
     if (h[/* size */0] > (h[/* data */1].length << 1)) {
       return resize(key_index, h);
     }
@@ -636,7 +636,7 @@ function MakeSeeded(H) {
           length: 3,
           tag: 0
         };
-        ++ h[0];
+        h[/* size */0] = h[/* size */0] + 1 | 0;
         if (h[/* size */0] > (h[/* data */1].length << 1)) {
           return resize(key_index, h);
         }
@@ -702,7 +702,7 @@ function Make(H) {
       tag: 0
     };
     h[/* data */1][i] = bucket;
-    ++ h[0];
+    h[/* size */0] = h[/* size */0] + 1 | 0;
     if (h[/* size */0] > (h[/* data */1].length << 1)) {
       return resize(key_index, h);
     }
@@ -854,7 +854,7 @@ function Make(H) {
           length: 3,
           tag: 0
         };
-        ++ h[0];
+        h[/* size */0] = h[/* size */0] + 1 | 0;
         if (h[/* size */0] > (h[/* data */1].length << 1)) {
           return resize(key_index, h);
         }
diff --git a/jscomp/stdlib/lexing.js b/jscomp/stdlib/lexing.js
index a28a9bae2d..57ead2f421 100644
--- a/jscomp/stdlib/lexing.js
+++ b/jscomp/stdlib/lexing.js
@@ -18,7 +18,7 @@ function engine(tbl, state, buf) {
       init[/* pos_fname */0],
       init[/* pos_lnum */1],
       init[/* pos_bol */2],
-      buf[/* lex_abs_pos */3] + buf[/* lex_curr_pos */5]
+      buf[/* lex_abs_pos */3] + buf[/* lex_curr_pos */5] | 0
     ];
   }
   return result;
@@ -33,7 +33,7 @@ function new_engine(tbl, state, buf) {
       init[/* pos_fname */0],
       init[/* pos_lnum */1],
       init[/* pos_bol */2],
-      buf[/* lex_abs_pos */3] + buf[/* lex_curr_pos */5]
+      buf[/* lex_abs_pos */3] + buf[/* lex_curr_pos */5] | 0
     ];
   }
   return result;
@@ -55,13 +55,13 @@ function from_function(f) {
             var lexbuf = param;
             var read = Caml_curry.app2(read_fun, aux_buffer, aux_buffer.length);
             var n = read > 0 ? read : (lexbuf[/* lex_eof_reached */8] = /* true */1, 0);
-            if (lexbuf[/* lex_buffer_len */2] + n > lexbuf[/* lex_buffer */1].length) {
-              if (lexbuf[/* lex_buffer_len */2] - lexbuf[/* lex_start_pos */4] + n <= lexbuf[/* lex_buffer */1].length) {
+            if ((lexbuf[/* lex_buffer_len */2] + n | 0) > lexbuf[/* lex_buffer */1].length) {
+              if ((lexbuf[/* lex_buffer_len */2] - lexbuf[/* lex_start_pos */4] + n | 0) <= lexbuf[/* lex_buffer */1].length) {
                 Bytes.blit(lexbuf[/* lex_buffer */1], lexbuf[/* lex_start_pos */4], lexbuf[/* lex_buffer */1], 0, lexbuf[/* lex_buffer_len */2] - lexbuf[/* lex_start_pos */4]);
               }
               else {
-                var newlen = Pervasives.min(2 * lexbuf[/* lex_buffer */1].length, Sys.max_string_length);
-                if (lexbuf[/* lex_buffer_len */2] - lexbuf[/* lex_start_pos */4] + n > newlen) {
+                var newlen = Pervasives.min((lexbuf[/* lex_buffer */1].length << 1), Sys.max_string_length);
+                if ((lexbuf[/* lex_buffer_len */2] - lexbuf[/* lex_start_pos */4] + n | 0) > newlen) {
                   throw [
                         Caml_builtin_exceptions.failure,
                         "Lexing.lex_refill: cannot grow buffer"
@@ -72,7 +72,7 @@ function from_function(f) {
                 lexbuf[/* lex_buffer */1] = newbuf;
               }
               var s = lexbuf[/* lex_start_pos */4];
-              lexbuf[3] += s;
+              lexbuf[/* lex_abs_pos */3] = lexbuf[/* lex_abs_pos */3] + s | 0;
               lexbuf[5] -= s;
               lexbuf[/* lex_start_pos */4] = 0;
               lexbuf[6] -= s;
@@ -87,7 +87,7 @@ function from_function(f) {
               }
             }
             Bytes.blit(aux_buffer, 0, lexbuf[/* lex_buffer */1], lexbuf[/* lex_buffer_len */2], n);
-            lexbuf[2] += n;
+            lexbuf[/* lex_buffer_len */2] = lexbuf[/* lex_buffer_len */2] + n | 0;
             return /* () */0;
           },
           new Array(1024),
@@ -164,7 +164,7 @@ function sub_lexeme_char_opt(lexbuf, i) {
 }
 
 function lexeme_char(lexbuf, i) {
-  return lexbuf[/* lex_buffer */1][lexbuf[/* lex_start_pos */4] + i];
+  return lexbuf[/* lex_buffer */1][lexbuf[/* lex_start_pos */4] + i | 0];
 }
 
 function lexeme_start(lexbuf) {
@@ -187,7 +187,7 @@ function new_line(lexbuf) {
   var lcp = lexbuf[/* lex_curr_p */11];
   lexbuf[/* lex_curr_p */11] = /* record */[
     lcp[/* pos_fname */0],
-    lcp[/* pos_lnum */1] + 1,
+    lcp[/* pos_lnum */1] + 1 | 0,
     lcp[/* pos_cnum */3],
     lcp[/* pos_cnum */3]
   ];
diff --git a/jscomp/stdlib/list.js b/jscomp/stdlib/list.js
index 341dc56b75..4c223a068b 100644
--- a/jscomp/stdlib/list.js
+++ b/jscomp/stdlib/list.js
@@ -14,7 +14,7 @@ function length(l) {
     var len = _len;
     if (param) {
       _param = param[1];
-      _len = len + 1;
+      _len = len + 1 | 0;
       continue ;
       
     }
@@ -132,7 +132,7 @@ function mapi(i, f, param) {
     var r = Caml_curry.app2(f, i, param[0]);
     return /* :: */[
             r,
-            mapi(i + 1, f, param[1])
+            mapi(i + 1 | 0, f, param[1])
           ];
   }
   else {
@@ -190,7 +190,7 @@ function iteri(f, l) {
     if (param) {
       Caml_curry.app2(f$1, i, param[0]);
       _param = param[1];
-      _i = i + 1;
+      _i = i + 1 | 0;
       continue ;
       
     }
diff --git a/jscomp/stdlib/map.js b/jscomp/stdlib/map.js
index 78bdd1aa7f..b212de1fb7 100644
--- a/jscomp/stdlib/map.js
+++ b/jscomp/stdlib/map.js
@@ -21,7 +21,7 @@ function Make(funarg) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -40,7 +40,7 @@ function Make(funarg) {
   var bal = function (l, x, d, r) {
     var hl = l ? l[4] : 0;
     var hr = r ? r[4] : 0;
-    if (hl > hr + 2) {
+    if (hl > (hr + 2 | 0)) {
       if (l) {
         var lr = l[3];
         var ld = l[2];
@@ -66,7 +66,7 @@ function Make(funarg) {
             ];
       }
     }
-    else if (hr > hl + 2) {
+    else if (hr > (hl + 2 | 0)) {
       if (r) {
         var rr = r[3];
         var rd = r[2];
@@ -98,7 +98,7 @@ function Make(funarg) {
               1: x,
               2: d,
               3: r,
-              4: hl >= hr ? hl + 1 : hr + 1,
+              4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
               length: 5,
               tag: 0
             };
@@ -420,10 +420,10 @@ function Make(funarg) {
       if (r) {
         var rh = r[4];
         var lh = l[4];
-        if (lh > rh + 2) {
+        if (lh > (rh + 2 | 0)) {
           return bal(l[0], l[1], l[2], join(l[3], v, d, r));
         }
-        else if (rh > lh + 2) {
+        else if (rh > (lh + 2 | 0)) {
           return bal(join(l, v, d, r[0]), r[1], r[2], r[3]);
         }
         else {
@@ -681,7 +681,7 @@ function Make(funarg) {
   };
   var cardinal = function (param) {
     if (param) {
-      return cardinal(param[0]) + 1 + cardinal(param[3]);
+      return (cardinal(param[0]) + 1 | 0) + cardinal(param[3]) | 0;
     }
     else {
       return 0;
diff --git a/jscomp/stdlib/marshal.js b/jscomp/stdlib/marshal.js
index f78e4712f7..ef081bc762 100644
--- a/jscomp/stdlib/marshal.js
+++ b/jscomp/stdlib/marshal.js
@@ -30,7 +30,7 @@ function data_size(buff, ofs) {
 }
 
 function total_size(buff, ofs) {
-  return 20 + data_size(buff, ofs);
+  return 20 + data_size(buff, ofs) | 0;
 }
 
 function from_bytes(buff, ofs) {
@@ -42,7 +42,7 @@ function from_bytes(buff, ofs) {
   }
   else {
     var len = Caml_primitive.caml_marshal_data_size(buff, ofs);
-    if (ofs > buff.length - (20 + len)) {
+    if (ofs > buff.length - (20 + len | 0)) {
       throw [
             Caml_builtin_exceptions.invalid_argument,
             "Marshal.from_bytes"
diff --git a/jscomp/stdlib/obj.js b/jscomp/stdlib/obj.js
index 11aadb202f..1441d713f2 100644
--- a/jscomp/stdlib/obj.js
+++ b/jscomp/stdlib/obj.js
@@ -21,7 +21,7 @@ function marshal(obj) {
 function unmarshal(str, pos) {
   return /* tuple */[
           Marshal.from_bytes(str, pos),
-          pos + Marshal.total_size(str, pos)
+          pos + Marshal.total_size(str, pos) | 0
         ];
 }
 
diff --git a/jscomp/stdlib/parsing.js b/jscomp/stdlib/parsing.js
index 0a67abd5a5..a0758effff 100644
--- a/jscomp/stdlib/parsing.js
+++ b/jscomp/stdlib/parsing.js
@@ -44,7 +44,7 @@ var env = /* record */[
 
 function grow_stacks() {
   var oldsize = env[/* stacksize */4];
-  var newsize = oldsize * 2;
+  var newsize = (oldsize << 1);
   var new_s = Caml_array.caml_make_vect(newsize, 0);
   var new_v = Caml_array.caml_make_vect(newsize, /* () */0);
   var new_start = Caml_array.caml_make_vect(newsize, Lexing.dummy_pos);
@@ -79,7 +79,7 @@ function yyparse(tables, start, lexer, lexbuf) {
   var init_curr_char = env[/* curr_char */6];
   var init_lval = env[/* lval */7];
   var init_errflag = env[/* errflag */15];
-  env[/* stackbase */5] = env[/* sp */13] + 1;
+  env[/* stackbase */5] = env[/* sp */13] + 1 | 0;
   env[/* curr_char */6] = start;
   env[/* symb_end */9] = lexbuf[/* lex_curr_p */11];
   try {
@@ -178,8 +178,8 @@ function symbol_start_pos() {
       return env[/* symb_end_stack */3][env[/* asp */10]];
     }
     else {
-      var st = env[/* symb_start_stack */2][env[/* asp */10] - i + 1];
-      var en = env[/* symb_end_stack */3][env[/* asp */10] - i + 1];
+      var st = env[/* symb_start_stack */2][env[/* asp */10] - i + 1 | 0];
+      var en = env[/* symb_end_stack */3][env[/* asp */10] - i + 1 | 0];
       if (Caml_obj.caml_notequal(st, en)) {
         return st;
       }
diff --git a/jscomp/stdlib/pervasives.js b/jscomp/stdlib/pervasives.js
index b1adb8b92d..fe0d4f6db5 100644
--- a/jscomp/stdlib/pervasives.js
+++ b/jscomp/stdlib/pervasives.js
@@ -64,7 +64,7 @@ function lnot(x) {
 
 var max_int = 2147483647;
 
-var min_int = max_int + 1;
+var min_int = max_int + 1 | 0;
 
 function $caret(a, b) {
   return a + b;
@@ -124,7 +124,7 @@ function valid_float_lexem(s) {
           return s;
         }
         else {
-          _i = i + 1;
+          _i = i + 1 | 0;
           continue ;
           
         }
@@ -133,7 +133,7 @@ function valid_float_lexem(s) {
         return s;
       }
       else {
-        _i = i + 1;
+        _i = i + 1 | 0;
         continue ;
         
       }
@@ -323,7 +323,7 @@ function unsafe_really_input(ic, s, _ofs, _len) {
       var r = Caml_primitive.caml_ml_input(ic, s, ofs, len);
       if (r) {
         _len = len - r;
-        _ofs = ofs + r;
+        _ofs = ofs + r | 0;
         continue ;
         
       }
@@ -382,7 +382,7 @@ function input_line(chan) {
           Caml_primitive.caml_ml_input(chan, res, 0, n - 1);
           Caml_io.caml_ml_input_char(chan);
           if (accu) {
-            var len$1 = len + n - 1;
+            var len$1 = (len + n | 0) - 1;
             return build_result(Caml_string.caml_create_string(len$1), len$1, /* :: */[
                         res,
                         accu
diff --git a/jscomp/stdlib/printexc.js b/jscomp/stdlib/printexc.js
index 739a91d5f2..2230f01370 100644
--- a/jscomp/stdlib/printexc.js
+++ b/jscomp/stdlib/printexc.js
@@ -139,7 +139,7 @@ function other_fields(x, i) {
                     1: ", %s%s",
                     length: 2,
                     tag: 0
-                  }), field(x, i), other_fields(x, i + 1));
+                  }), field(x, i), other_fields(x, i + 1 | 0));
   }
 }
 
@@ -235,17 +235,17 @@ function to_string(x) {
     else if (x[0] === Caml_builtin_exceptions.match_failure) {
       var match$1 = x[1];
       var $$char = match$1[2];
-      return Caml_curry.app5(Printf.sprintf(locfmt), match$1[0], match$1[1], $$char, $$char + 5, "Pattern matching failed");
+      return Caml_curry.app5(Printf.sprintf(locfmt), match$1[0], match$1[1], $$char, $$char + 5 | 0, "Pattern matching failed");
     }
     else if (x[0] === Caml_builtin_exceptions.assert_failure) {
       var match$2 = x[1];
       var $$char$1 = match$2[2];
-      return Caml_curry.app5(Printf.sprintf(locfmt), match$2[0], match$2[1], $$char$1, $$char$1 + 6, "Assertion failed");
+      return Caml_curry.app5(Printf.sprintf(locfmt), match$2[0], match$2[1], $$char$1, $$char$1 + 6 | 0, "Assertion failed");
     }
     else if (x[0] === Caml_builtin_exceptions.undefined_recursive_module) {
       var match$3 = x[1];
       var $$char$2 = match$3[2];
-      return Caml_curry.app5(Printf.sprintf(locfmt), match$3[0], match$3[1], $$char$2, $$char$2 + 6, "Undefined recursive module");
+      return Caml_curry.app5(Printf.sprintf(locfmt), match$3[0], match$3[1], $$char$2, $$char$2 + 6 | 0, "Undefined recursive module");
     }
     else if ((x.tag | 0) !== 0) {
       return x[0];
diff --git a/jscomp/stdlib/queue.js b/jscomp/stdlib/queue.js
index c760af2176..6c0d990833 100644
--- a/jscomp/stdlib/queue.js
+++ b/jscomp/stdlib/queue.js
@@ -33,7 +33,7 @@ function add(x, q) {
       x,
       head
     ];
-    ++ q[0];
+    q[/* length */0] = q[/* length */0] + 1 | 0;
     tail[/* next */1] = cell;
     q[/* tail */1] = cell;
     return /* () */0;
@@ -188,7 +188,7 @@ function transfer(q1, q2) {
       tail1[/* next */1] = head2;
       tail2[/* next */1] = head1;
     }
-    q2[0] += length1;
+    q2[/* length */0] = q2[/* length */0] + length1 | 0;
     q2[/* tail */1] = tail1;
     return /* () */0;
   }
diff --git a/jscomp/stdlib/random.js b/jscomp/stdlib/random.js
index 948bb1b624..2b1a943533 100644
--- a/jscomp/stdlib/random.js
+++ b/jscomp/stdlib/random.js
@@ -31,7 +31,7 @@ function full_init(s, seed) {
     return Digest.string(accu + x);
   };
   var extract = function (d) {
-    return d.charCodeAt(0) + (d.charCodeAt(1) << 8) + (d.charCodeAt(2) << 16) + (d.charCodeAt(3) << 24);
+    return ((d.charCodeAt(0) + (d.charCodeAt(1) << 8) | 0) + (d.charCodeAt(2) << 16) | 0) + (d.charCodeAt(3) << 24) | 0;
   };
   var seed$1 = seed.length ? seed : /* int array */[0];
   var l = seed$1.length;
@@ -39,7 +39,7 @@ function full_init(s, seed) {
     s[/* st */0][i] = i;
   }
   var accu = "x";
-  for(var i$1 = 0 ,i_finish = 54 + Pervasives.max(55, l); i$1<= i_finish; ++i$1){
+  for(var i$1 = 0 ,i_finish = 54 + Pervasives.max(55, l) | 0; i$1<= i_finish; ++i$1){
     var j = i$1 % 55;
     var k = i$1 % l;
     accu = combine(accu, seed$1[k]);
@@ -66,9 +66,9 @@ function copy(s) {
 }
 
 function bits(s) {
-  s[/* idx */1] = (s[/* idx */1] + 1) % 55;
+  s[/* idx */1] = (s[/* idx */1] + 1 | 0) % 55;
   var curval = s[/* st */0][s[/* idx */1]];
-  var newval = s[/* st */0][(s[/* idx */1] + 24) % 55] + (curval ^ (curval >>> 25) & 31);
+  var newval = s[/* st */0][(s[/* idx */1] + 24 | 0) % 55] + (curval ^ (curval >>> 25) & 31) | 0;
   var newval30 = newval & 1073741823;
   s[/* st */0][s[/* idx */1]] = newval30;
   return newval30;
@@ -87,7 +87,7 @@ function $$int(s, bound) {
     while(true) {
       var r = bits(s$1);
       var v = r % n;
-      if (r - v > 1073741823 - n + 1) {
+      if (r - v > (1073741823 - n + 1 | 0)) {
         continue ;
         
       }
diff --git a/jscomp/stdlib/scanf.js b/jscomp/stdlib/scanf.js
index 7b6da04a0b..b7637faec1 100644
--- a/jscomp/stdlib/scanf.js
+++ b/jscomp/stdlib/scanf.js
@@ -20,9 +20,9 @@ function next_char(ib) {
     var c = Caml_curry.app1(ib[/* get_next_char */6], /* () */0);
     ib[/* current_char */1] = c;
     ib[/* current_char_is_valid */2] = /* true */1;
-    ++ ib[3];
+    ib[/* char_count */3] = ib[/* char_count */3] + 1 | 0;
     if (c === /* "\n" */10) {
-      ++ ib[4];
+      ib[/* line_count */4] = ib[/* line_count */4] + 1 | 0;
     }
     return c;
   }
@@ -96,7 +96,7 @@ function token(ib) {
   var tokbuf = ib[/* tokbuf */7];
   var tok = Buffer.contents(tokbuf);
   tokbuf[/* position */1] = 0;
-  ++ ib[5];
+  ib[/* token_count */5] = ib[/* token_count */5] + 1 | 0;
   return tok;
 }
 
@@ -134,7 +134,7 @@ function from_string(s) {
     }
     else {
       var c = s.charCodeAt(i[0]);
-      ++ i[0];
+      i[0] = i[0] + 1 | 0;
       return c;
     }
   };
@@ -165,7 +165,7 @@ function from_ic(scan_close_ic, iname, ic) {
   var next = function () {
     if (i[0] < lim[0]) {
       var c = buf[i[0]];
-      ++ i[0];
+      i[0] = i[0] + 1 | 0;
       return c;
     }
     else if (eof[0]) {
@@ -363,7 +363,7 @@ function check_char(ib, _c) {
           return 0;
         }
         else {
-          var switcher = c$1 - 9;
+          var switcher = c$1 - 9 | 0;
           if (switcher > 4 || switcher < 0) {
             if (switcher !== 23) {
               return /* () */0;
@@ -453,7 +453,7 @@ function token_bool(ib) {
 function token_int_literal(conv, ib) {
   var tok;
   var exit = 0;
-  var switcher = conv - 88;
+  var switcher = conv - 88 | 0;
   if (switcher > 32 || switcher < 0) {
     exit = 1;
   }
@@ -702,7 +702,7 @@ function scan_octal_int(param, param$1) {
 }
 
 function is_hexa_digit(param) {
-  var switcher = param - 48;
+  var switcher = param - 48 | 0;
   if (switcher > 22 || switcher < 0) {
     if (switcher > 54 || switcher < 49) {
       return /* false */0;
@@ -725,7 +725,7 @@ function scan_hexadecimal_int(param, param$1) {
 
 function scan_sign(width, ib) {
   var c = checked_peek_char(ib);
-  var switcher = c - 43;
+  var switcher = c - 43 | 0;
   if (switcher > 2 || switcher < 0) {
     return width;
   }
@@ -748,7 +748,7 @@ function scan_optionally_signed_decimal_int(width, ib) {
 
 function scan_int_conv(conv, width, ib) {
   var exit = 0;
-  var switcher = conv - 88;
+  var switcher = conv - 88 | 0;
   if (switcher > 32 || switcher < 0) {
     exit = 1;
   }
@@ -935,7 +935,7 @@ function scan_caml_float(width, precision, ib) {
           ];
     }
     else {
-      var switcher = c - 69;
+      var switcher = c - 69 | 0;
       if (switcher > 32 || switcher < 0) {
         if (switcher !== -23) {
           throw [
@@ -990,7 +990,7 @@ function scan_string(stp, width, ib) {
         }
       }
       else {
-        var switcher = c - 9;
+        var switcher = c - 9 | 0;
         if (switcher > 4 || switcher < 0) {
           if (switcher !== 23) {
             _width = store_char(width$1, ib, c);
@@ -1027,7 +1027,7 @@ function char_for_backslash(c) {
       return c;
     }
     else {
-      switch (c - 110) {
+      switch (c - 110 | 0) {
         case 0 : 
             return /* "\n" */10;
         case 4 : 
@@ -1052,7 +1052,7 @@ function char_for_backslash(c) {
 }
 
 function char_for_decimal_code(c0, c1, c2) {
-  var c = 100 * (c0 - /* "0" */48) + 10 * (c1 - /* "0" */48) + (c2 - /* "0" */48);
+  var c = (Caml_primitive.imul(100, c0 - /* "0" */48) + Caml_primitive.imul(10, c1 - /* "0" */48) | 0) + (c2 - /* "0" */48) | 0;
   if (c < 0 || c > 255) {
     var s = Caml_curry.app3(Printf.sprintf(/* Format */{
               0: /* String_literal */{
@@ -1100,7 +1100,7 @@ function hexadecimal_value_of_char(c) {
 }
 
 function char_for_hexadecimal_code(c1, c2) {
-  var c = 16 * hexadecimal_value_of_char(c1) + hexadecimal_value_of_char(c2);
+  var c = (hexadecimal_value_of_char(c1) << 4) + hexadecimal_value_of_char(c2) | 0;
   if (c < 0 || c > 255) {
     var s = Caml_curry.app2(Printf.sprintf(/* Format */{
               0: /* String_literal */{
@@ -1176,7 +1176,7 @@ function scan_backslash_char(width, ib) {
   var exit = 0;
   if (c >= 40) {
     if (c >= 58) {
-      var switcher = c - 92;
+      var switcher = c - 92 | 0;
       if (switcher > 28 || switcher < 0) {
         return bad_input_escape(c);
       }
@@ -1216,7 +1216,7 @@ function scan_backslash_char(width, ib) {
           case 28 : 
               var get_digit = function () {
                 var c = next_char(ib);
-                var switcher = c - 48;
+                var switcher = c - 48 | 0;
                 if (switcher > 22 || switcher < 0) {
                   if (switcher > 54 || switcher < 49) {
                     return bad_input_escape(c);
@@ -2281,7 +2281,7 @@ function sscanf_format(s, format, f) {
 
 function string_to_String(s) {
   var l = s.length;
-  var b = Buffer.create(l + 2);
+  var b = Buffer.create(l + 2 | 0);
   Buffer.add_char(b, /* "\"" */34);
   for(var i = 0 ,i_finish = l - 1; i<= i_finish; ++i){
     var c = s.charCodeAt(i);
diff --git a/jscomp/stdlib/set.js b/jscomp/stdlib/set.js
index 5f543a0c73..e5a133dc91 100644
--- a/jscomp/stdlib/set.js
+++ b/jscomp/stdlib/set.js
@@ -21,7 +21,7 @@ function Make(funarg) {
             0: l,
             1: v,
             2: r,
-            3: hl >= hr ? hl + 1 : hr + 1,
+            3: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 4,
             tag: 0
           };
@@ -29,7 +29,7 @@ function Make(funarg) {
   var bal = function (l, v, r) {
     var hl = l ? l[3] : 0;
     var hr = r ? r[3] : 0;
-    if (hl > hr + 2) {
+    if (hl > (hr + 2 | 0)) {
       if (l) {
         var lr = l[2];
         var lv = l[1];
@@ -54,7 +54,7 @@ function Make(funarg) {
             ];
       }
     }
-    else if (hr > hl + 2) {
+    else if (hr > (hl + 2 | 0)) {
       if (r) {
         var rr = r[2];
         var rv = r[1];
@@ -84,7 +84,7 @@ function Make(funarg) {
               0: l,
               1: v,
               2: r,
-              3: hl >= hr ? hl + 1 : hr + 1,
+              3: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
               length: 4,
               tag: 0
             };
@@ -150,10 +150,10 @@ function Make(funarg) {
       if (r) {
         var rh = r[3];
         var lh = l[3];
-        if (lh > rh + 2) {
+        if (lh > (rh + 2 | 0)) {
           return bal(l[0], l[1], join(l[2], v, r));
         }
-        else if (rh > lh + 2) {
+        else if (rh > (lh + 2 | 0)) {
           return bal(join(l, v, r[0]), r[1], r[2]);
         }
         else {
@@ -659,7 +659,7 @@ function Make(funarg) {
   };
   var cardinal = function (param) {
     if (param) {
-      return cardinal(param[0]) + 1 + cardinal(param[2]);
+      return (cardinal(param[0]) + 1 | 0) + cardinal(param[2]) | 0;
     }
     else {
       return 0;
diff --git a/jscomp/stdlib/sort.js b/jscomp/stdlib/sort.js
index 87be838a3d..401dd255b7 100644
--- a/jscomp/stdlib/sort.js
+++ b/jscomp/stdlib/sort.js
@@ -118,7 +118,7 @@ function array(cmp, arr) {
       var hi = _hi;
       var lo = _lo;
       if (hi - lo >= 6) {
-        var mid = (lo + hi >>> 1);
+        var mid = ((lo + hi | 0) >>> 1);
         if (Caml_curry.app2(cmp, arr[mid], arr[lo])) {
           swap(arr, mid, lo);
         }
@@ -130,7 +130,7 @@ function array(cmp, arr) {
           
         }
         var pivot = arr[mid];
-        var i = lo + 1;
+        var i = lo + 1 | 0;
         var j = hi - 1;
         if (!Caml_curry.app2(cmp, pivot, arr[hi]) || !Caml_curry.app2(cmp, arr[lo], pivot)) {
           throw [
@@ -140,16 +140,16 @@ function array(cmp, arr) {
         }
         while(i < j) {
           while(!Caml_curry.app2(cmp, pivot, arr[i])) {
-            ++ i;
+            i = i + 1 | 0;
           };
           while(!Caml_curry.app2(cmp, arr[j], pivot)) {
-            -- j;
+            j = j - 1 | 0;
           };
           if (i < j) {
             swap(arr, i, j);
           }
-          ++ i;
-          -- j;
+          i = i + 1 | 0;
+          j = j - 1 | 0;
         };
         if (j - lo <= hi - i) {
           qsort(lo, j);
@@ -177,7 +177,7 @@ function array(cmp, arr) {
       var j = i - 1;
       while(j >= 1 && !Caml_curry.app2(cmp, arr[j - 1], val_i)) {
         arr[j] = arr[j - 1];
-        -- j;
+        j = j - 1 | 0;
       };
       arr[j] = val_i;
     }
diff --git a/jscomp/stdlib/stream.js b/jscomp/stdlib/stream.js
index a5d9732392..ab0cbc9cab 100644
--- a/jscomp/stdlib/stream.js
+++ b/jscomp/stdlib/stream.js
@@ -129,7 +129,7 @@ function get_data(count, _d) {
             }
             if (b[/* len */2]) {
               var r = b[/* buff */1][b[/* ind */3]];
-              ++ b[3];
+              b[/* ind */3] = b[/* ind */3] + 1 | 0;
               return /* Scons */{
                       0: r,
                       1: d,
@@ -236,14 +236,14 @@ function junk(s) {
     else {
       switch (match.tag | 0) {
         case 0 : 
-            ++ s[0];
+            s[0] = s[/* count */0] + 1 | 0;
             s[1] = match[1];
             return /* () */0;
         case 3 : 
             var g = match[0];
             var match$1 = g[/* curr */0];
             if (match$1) {
-              ++ s[0];
+              s[0] = s[/* count */0] + 1 | 0;
               g[/* curr */0] = /* None */0;
               return /* () */0;
             }
@@ -253,8 +253,8 @@ function junk(s) {
             break;
         case 4 : 
             var b = match[0];
-            ++ s[0];
-            ++ b[3];
+            s[0] = s[/* count */0] + 1 | 0;
+            b[/* ind */3] = b[/* ind */3] + 1 | 0;
             return /* () */0;
         default:
           exit = 1;
@@ -287,7 +287,7 @@ function nget(n, s) {
     if (match) {
       var a = match[0];
       junk(s);
-      var match$1 = nget(n - 1, s);
+      var match$1 = nget(n - 1 | 0, s);
       return /* tuple */[
               /* :: */[
                 a,
@@ -299,7 +299,7 @@ function nget(n, s) {
                 length: 2,
                 tag: 0
               },
-              match$1[2] + 1
+              match$1[2] + 1 | 0
             ];
     }
     else {
@@ -390,7 +390,7 @@ function of_string(s) {
   return from(function () {
               var c = count[0];
               if (c < s.length) {
-                ++ count[0];
+                count[0] = count[0] + 1 | 0;
                 return /* Some */[s.charCodeAt(c)];
               }
               else {
@@ -404,7 +404,7 @@ function of_bytes(s) {
   return from(function () {
               var c = count[0];
               if (c < s.length) {
-                ++ count[0];
+                count[0] = count[0] + 1 | 0;
                 return /* Some */[s[c]];
               }
               else {
diff --git a/jscomp/stdlib/string.js b/jscomp/stdlib/string.js
index 3f4b10b849..74ab6520ba 100644
--- a/jscomp/stdlib/string.js
+++ b/jscomp/stdlib/string.js
@@ -1,9 +1,10 @@
 // Generated CODE, PLEASE EDIT WITH CARE
 'use strict';
 
-var Bytes       = require("./bytes");
-var Caml_string = require("../runtime/caml_string");
-var List        = require("./list");
+var Bytes          = require("./bytes");
+var Caml_primitive = require("../runtime/caml_primitive");
+var Caml_string    = require("../runtime/caml_string");
+var List           = require("./list");
 
 function make(n, c) {
   return Caml_string.bytes_to_string(Bytes.make(n, c));
@@ -27,18 +28,18 @@ function concat(sep, l) {
     var num = [0];
     var len = [0];
     List.iter(function (s) {
-          ++ num[0];
-          len[0] += s.length;
+          num[0] = num[0] + 1 | 0;
+          len[0] = len[0] + s.length | 0;
           return /* () */0;
         }, l);
-    var r = Caml_string.caml_create_string(len[0] + sep.length * (num[0] - 1));
+    var r = Caml_string.caml_create_string(len[0] + Caml_primitive.imul(sep.length, num[0] - 1) | 0);
     Caml_string.caml_blit_string(hd, 0, r, 0, hd.length);
     var pos = [hd.length];
     List.iter(function (s) {
           Caml_string.caml_blit_string(sep, 0, r, pos[0], sep.length);
-          pos[0] += sep.length;
+          pos[0] = pos[0] + sep.length | 0;
           Caml_string.caml_blit_string(s, 0, r, pos[0], s.length);
-          pos[0] += s.length;
+          pos[0] = pos[0] + s.length | 0;
           return /* () */0;
         }, l[1]);
     return Caml_string.bytes_to_string(r);
@@ -65,7 +66,7 @@ function mapi(f, s) {
 }
 
 function is_space(param) {
-  var switcher = param - 9;
+  var switcher = param - 9 | 0;
   if (switcher > 4 || switcher < 0) {
     if (switcher !== 23) {
       return /* false */0;
@@ -130,7 +131,7 @@ function escaped(s) {
         }
         if (exit === 1) {
           if (Caml_string.caml_is_printable(c)) {
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             
           }
diff --git a/jscomp/stdlib/weak.js b/jscomp/stdlib/weak.js
index fcf123ecf1..982c35c4e9 100644
--- a/jscomp/stdlib/weak.js
+++ b/jscomp/stdlib/weak.js
@@ -15,14 +15,14 @@ function length(x) {
 }
 
 function fill(ar, ofs, len, x) {
-  if (ofs < 0 || len < 0 || ofs + len > ar.length - 1) {
+  if (ofs < 0 || len < 0 || (ofs + len | 0) > ar.length - 1) {
     throw [
           Caml_builtin_exceptions.invalid_argument,
           "Weak.fill"
         ];
   }
   else {
-    for(var i = ofs ,i_finish = ofs + len - 1; i<= i_finish; ++i){
+    for(var i = ofs ,i_finish = (ofs + len | 0) - 1; i<= i_finish; ++i){
       Caml_primitive.caml_weak_set(ar, i, x);
     }
     return /* () */0;
@@ -69,12 +69,12 @@ function Make(H) {
                     var match = Caml_primitive.caml_weak_get(b, i);
                     if (match) {
                       _accu = Caml_curry.app2(f, match[0], accu);
-                      _i = i + 1;
+                      _i = i + 1 | 0;
                       continue ;
                       
                     }
                     else {
-                      _i = i + 1;
+                      _i = i + 1 | 0;
                       continue ;
                       
                     }
@@ -95,12 +95,12 @@ function Make(H) {
                     var match = Caml_primitive.caml_weak_get(b, i);
                     if (match) {
                       Caml_curry.app1(f, match[0]);
-                      _i = i + 1;
+                      _i = i + 1 | 0;
                       continue ;
                       
                     }
                     else {
-                      _i = i + 1;
+                      _i = i + 1 | 0;
                       continue ;
                       
                     }
@@ -122,12 +122,12 @@ function Make(H) {
                     var match = Caml_primitive.caml_weak_check(b, i);
                     if (match !== 0) {
                       Caml_curry.app3(f, b, t[/* hashes */1][j], i);
-                      _i = i + 1;
+                      _i = i + 1 | 0;
                       continue ;
                       
                     }
                     else {
-                      _i = i + 1;
+                      _i = i + 1 | 0;
                       continue ;
                       
                     }
@@ -145,8 +145,8 @@ function Make(H) {
       else {
         _accu = accu + (
           Caml_primitive.caml_weak_check(b, i) ? 1 : 0
-        );
-        _i = i + 1;
+        ) | 0;
+        _i = i + 1 | 0;
         continue ;
         
       }
@@ -158,10 +158,10 @@ function Make(H) {
               }, t[/* table */0], 0);
   };
   var next_sz = function (n) {
-    return Pervasives.min((3 * n / 2 | 0) + 3, Sys.max_array_length);
+    return Pervasives.min((Caml_primitive.imul(3, n) / 2 | 0) + 3 | 0, Sys.max_array_length);
   };
   var prev_sz = function (n) {
-    return ((n - 3) * 2 + 2) / 3 | 0;
+    return ((n - 3 << 1) + 2 | 0) / 3 | 0;
   };
   var test_shrink_bucket = function (t) {
     var bucket = t[/* table */0][t[/* rover */4]];
@@ -176,7 +176,7 @@ function Make(H) {
           var i = _i;
           if (j >= prev_len) {
             if (Caml_primitive.caml_weak_check(bucket, i)) {
-              _i = i + 1;
+              _i = i + 1 | 0;
               continue ;
               
             }
@@ -184,7 +184,7 @@ function Make(H) {
               Caml_primitive.caml_weak_blit(bucket, j, bucket, i, 1);
               hbucket[i] = hbucket[j];
               _j = j - 1;
-              _i = i + 1;
+              _i = i + 1 | 0;
               continue ;
               
             }
@@ -201,7 +201,7 @@ function Make(H) {
       };
       loop(0, bucket.length - 1 - 1);
       if (prev_len) {
-        Caml_obj.caml_obj_truncate(bucket, prev_len + 1);
+        Caml_obj.caml_obj_truncate(bucket, prev_len + 1 | 0);
         Caml_obj.caml_obj_truncate(hbucket, prev_len);
       }
       else {
@@ -213,7 +213,7 @@ function Make(H) {
       }
       
     }
-    t[/* rover */4] = (t[/* rover */4] + 1) % t[/* table */0].length;
+    t[/* rover */4] = (t[/* rover */4] + 1 | 0) % t[/* table */0].length;
     return /* () */0;
   };
   var add_aux = function (t, setter, d, h, index) {
@@ -224,7 +224,7 @@ function Make(H) {
     while(true) {
       var i = _i;
       if (i >= sz) {
-        var newsz = Pervasives.min((3 * sz / 2 | 0) + 3, Sys.max_array_length - 1);
+        var newsz = Pervasives.min((Caml_primitive.imul(3, sz) / 2 | 0) + 3 | 0, Sys.max_array_length - 1);
         if (newsz <= sz) {
           throw [
                 Caml_builtin_exceptions.failure,
@@ -240,7 +240,7 @@ function Make(H) {
         t[/* table */0][index] = newbucket;
         t[/* hashes */1][index] = newhashes;
         if (sz <= t[/* limit */2] && newsz > t[/* limit */2]) {
-          ++ t[3];
+          t[/* oversize */3] = t[/* oversize */3] + 1 | 0;
           for(var _i$1 = 0; _i$1<= 2; ++_i$1){
             test_shrink_bucket(t);
           }
@@ -279,7 +279,7 @@ function Make(H) {
         }
       }
       else if (Caml_primitive.caml_weak_check(bucket, i)) {
-        _i = i + 1;
+        _i = i + 1 | 0;
         continue ;
         
       }
@@ -317,25 +317,25 @@ function Make(H) {
               return match$1[0];
             }
             else {
-              _i = i + 1;
+              _i = i + 1 | 0;
               continue ;
               
             }
           }
           else {
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             
           }
         }
         else {
-          _i = i + 1;
+          _i = i + 1 | 0;
           continue ;
           
         }
       }
       else {
-        _i = i + 1;
+        _i = i + 1 | 0;
         continue ;
         
       }
@@ -373,19 +373,19 @@ function Make(H) {
             return Caml_curry.app2(iffound, bucket, i);
           }
           else {
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             
           }
         }
         else {
-          _i = i + 1;
+          _i = i + 1 | 0;
           continue ;
           
         }
       }
       else {
-        _i = i + 1;
+        _i = i + 1 | 0;
         continue ;
         
       }
@@ -425,30 +425,30 @@ function Make(H) {
                 match$1[0],
                 accu
               ];
-              _i = i + 1;
+              _i = i + 1 | 0;
               continue ;
               
             }
             else {
-              _i = i + 1;
+              _i = i + 1 | 0;
               continue ;
               
             }
           }
           else {
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             
           }
         }
         else {
-          _i = i + 1;
+          _i = i + 1 | 0;
           continue ;
           
         }
       }
       else {
-        _i = i + 1;
+        _i = i + 1 | 0;
         continue ;
         
       }
@@ -461,7 +461,7 @@ function Make(H) {
           return Caml_obj.caml_compare(prim, prim$1);
         }, lens);
     var totlen = $$Array.fold_left(function (prim, prim$1) {
-          return prim + prim$1;
+          return prim + prim$1 | 0;
         }, 0, lens);
     return /* tuple */[
             len,
diff --git a/jscomp/test/a_scope_bug.js b/jscomp/test/a_scope_bug.js
index 6b065057e2..1f8a9ed9b7 100644
--- a/jscomp/test/a_scope_bug.js
+++ b/jscomp/test/a_scope_bug.js
@@ -1,12 +1,13 @@
 // Generated CODE, PLEASE EDIT WITH CARE
 'use strict';
 
+var Caml_primitive = require("../runtime/caml_primitive");
 
 function odd(_z) {
   while(true) {
     var z = _z;
-    var even = z * z;
-    var a = even + 4 + even;
+    var even = Caml_primitive.imul(z, z);
+    var a = (even + 4 | 0) + even | 0;
     console.log("" + a);
     _z = 32;
     continue ;
diff --git a/jscomp/test/and_or_tailcall_test.js b/jscomp/test/and_or_tailcall_test.js
index 3de4d54b84..861c1baa5b 100644
--- a/jscomp/test/and_or_tailcall_test.js
+++ b/jscomp/test/and_or_tailcall_test.js
@@ -10,7 +10,7 @@ function f(b, _, _n) {
       return /* false */0;
     }
     else if (b) {
-      _n = n + 1;
+      _n = n + 1 | 0;
       continue ;
       
     }
@@ -30,7 +30,7 @@ function or_f(b, _, _n) {
       return /* true */1;
     }
     else {
-      _n = n + 1;
+      _n = n + 1 | 0;
       continue ;
       
     }
diff --git a/jscomp/test/ari_regress_test.js b/jscomp/test/ari_regress_test.js
index ef6c3aab27..0513b82e21 100644
--- a/jscomp/test/ari_regress_test.js
+++ b/jscomp/test/ari_regress_test.js
@@ -9,17 +9,17 @@ var g = 7;
 var h = [0];
 
 function gg(x, y) {
-  var u = x + y;
+  var u = x + y | 0;
   return function (z) {
-    return u + z;
+    return u + z | 0;
   };
 }
 
 function g1(x, y) {
-  var u = x + y;
-  ++ h[0];
+  var u = x + y | 0;
+  h[0] = h[0] + 1 | 0;
   return function (xx, yy) {
-    return xx + yy + u;
+    return (xx + yy | 0) + u | 0;
   };
 }
 
diff --git a/jscomp/test/array_test.js b/jscomp/test/array_test.js
index f770dc7e01..73cf835058 100644
--- a/jscomp/test/array_test.js
+++ b/jscomp/test/array_test.js
@@ -15,8 +15,8 @@ function is_sorted(x) {
     if (i >= len - 1) {
       return /* true */1;
     }
-    else if (Caml_obj.caml_lessthan(x[i], x[i + 1])) {
-      _i = i + 1;
+    else if (Caml_obj.caml_lessthan(x[i], x[i + 1 | 0])) {
+      _i = i + 1 | 0;
       continue ;
       
     }
@@ -159,7 +159,7 @@ var array_suites_001 = /* :: */[
                 0
               ];
               var v = $$Array.init(3, function (x) {
-                    return x * 2;
+                    return (x << 1);
                   });
               $$Array.blit(v, 1, u, 1, 2);
               return /* Eq */{
diff --git a/jscomp/test/bdd.js b/jscomp/test/bdd.js
index 7e29c7a6fc..5212d8644e 100644
--- a/jscomp/test/bdd.js
+++ b/jscomp/test/bdd.js
@@ -2,6 +2,7 @@
 'use strict';
 
 var Caml_builtin_exceptions = require("../runtime/caml_builtin_exceptions");
+var Caml_primitive          = require("../runtime/caml_primitive");
 var Caml_array              = require("../runtime/caml_array");
 
 function $$eval(_bdd, vars) {
@@ -48,12 +49,12 @@ var nodeC = [1];
 
 var sz_1 = [initSize_1];
 
-var htab = [Caml_array.caml_make_vect(sz_1[0] + 1, /* [] */0)];
+var htab = [Caml_array.caml_make_vect(sz_1[0] + 1 | 0, /* [] */0)];
 
 var n_items = [0];
 
 function hashVal(x, y, v) {
-  return (x << 1) + y + (v << 2);
+  return ((x << 1) + y | 0) + (v << 2) | 0;
 }
 
 function resize(newSize) {
@@ -105,10 +106,10 @@ function insert(idl, idh, v, ind, bucket, newNode) {
       newNode,
       bucket
     ];
-    return ++ n_items[0];
+    return n_items[0] = n_items[0] + 1 | 0;
   }
   else {
-    resize(sz_1[0] + sz_1[0] + 2);
+    resize((sz_1[0] + sz_1[0] | 0) + 2 | 0);
     var ind$1 = hashVal(idl, idh, v) & sz_1[0];
     htab[0][ind$1] = /* :: */[
       newNode,
@@ -120,7 +121,7 @@ function insert(idl, idh, v, ind, bucket, newNode) {
 
 function resetUnique() {
   sz_1[0] = initSize_1;
-  htab[0] = Caml_array.caml_make_vect(sz_1[0] + 1, /* [] */0);
+  htab[0] = Caml_array.caml_make_vect(sz_1[0] + 1 | 0, /* [] */0);
   n_items[0] = 0;
   nodeC[0] = 1;
   return /* () */0;
@@ -160,7 +161,7 @@ function mkNode(low, v, high) {
         }
       }
       else {
-        var n_002 = (++ nodeC[0], nodeC[0]);
+        var n_002 = (nodeC[0] = nodeC[0] + 1 | 0, nodeC[0]);
         var n$1 = /* Node */{
           0: low,
           1: v,
@@ -213,7 +214,7 @@ var notslot1 = Caml_array.caml_make_vect(1999, 0);
 var notslot2 = Caml_array.caml_make_vect(1999, one);
 
 function hash(x, y) {
-  return ((x << 1) + y) % 1999;
+  return ((x << 1) + y | 0) % 1999;
 }
 
 function not(n) {
@@ -364,7 +365,7 @@ function hwb(n) {
       return mkNode(zero, i, one);
     }
     else {
-      return xor(and2(not(mkNode(zero, i, one)), h(i + 1, j)), and2(mkNode(zero, i, one), g(i + 1, j)));
+      return xor(and2(not(mkNode(zero, i, one)), h(i + 1 | 0, j)), and2(mkNode(zero, i, one), g(i + 1 | 0, j)));
     }
   };
   return h(0, n - 1);
@@ -373,7 +374,7 @@ function hwb(n) {
 var seed = [0];
 
 function random() {
-  seed[0] = seed[0] * 25173 + 17431;
+  seed[0] = Caml_primitive.imul(seed[0], 25173) + 17431 | 0;
   return +((seed[0] & 1) > 0);
 }
 
@@ -406,7 +407,7 @@ function test_hwb(bdd, vars) {
   var ntrue = 0;
   for(var i = 0 ,i_finish = vars.length - 1; i<= i_finish; ++i){
     if (vars[i]) {
-      ++ ntrue;
+      ntrue = ntrue + 1 | 0;
     }
     
   }
diff --git a/jscomp/test/bigarray_test.js b/jscomp/test/bigarray_test.js
index c8fe7d36e2..690b742e5a 100644
--- a/jscomp/test/bigarray_test.js
+++ b/jscomp/test/bigarray_test.js
@@ -1,9 +1,10 @@
 // Generated CODE, PLEASE EDIT WITH CARE
 'use strict';
 
-var Caml_bigarray = require("../runtime/caml_bigarray");
-var Bigarray      = require("../stdlib/bigarray");
-var Caml_curry    = require("../runtime/caml_curry");
+var Caml_bigarray  = require("../runtime/caml_bigarray");
+var Bigarray       = require("../stdlib/bigarray");
+var Caml_primitive = require("../runtime/caml_primitive");
+var Caml_curry     = require("../runtime/caml_curry");
 
 var v = Caml_curry.app3(Bigarray.Array1[0], /* Int32 */6, /* C_layout */0, 20);
 
@@ -20,8 +21,8 @@ var vv = Caml_curry.app3(Bigarray.Array1[0], /* Int32 */6, /* Fortran_layout */1
 function init(v) {
   for(var i = 0 ,i_finish = Caml_bigarray.caml_ba_dim_1(v) - 1; i<= i_finish; ++i){
     v[i] = /* float array */[
-      i * i,
-      i * i * i
+      Caml_primitive.imul(i, i),
+      Caml_primitive.imul(Caml_primitive.imul(i, i), i)
     ];
   }
   return /* () */0;
diff --git a/jscomp/test/class_type_ffi_test.js b/jscomp/test/class_type_ffi_test.js
index 27cd188dc6..a52f340103 100644
--- a/jscomp/test/class_type_ffi_test.js
+++ b/jscomp/test/class_type_ffi_test.js
@@ -14,7 +14,7 @@ function sum_float_array(arr) {
 function sum_int_array(arr) {
   var v = 0;
   for(var i = 0 ,i_finish = arr.length - 1; i<= i_finish; ++i){
-    v += arr[i];
+    v = v + arr[i] | 0;
   }
   return v;
 }
diff --git a/jscomp/test/complex_if_test.js b/jscomp/test/complex_if_test.js
index 6737785a0f..28b3556d60 100644
--- a/jscomp/test/complex_if_test.js
+++ b/jscomp/test/complex_if_test.js
@@ -7,7 +7,7 @@ var Caml_string = require("../runtime/caml_string");
 
 function fib(n) {
   if (n !== 1 && n !== 23) {
-    return fib(n - 1) + fib(n - 2);
+    return fib(n - 1) + fib(n - 2) | 0;
   }
   else {
     return 11111123;
@@ -20,7 +20,7 @@ function escaped(s) {
     var match = s[i];
     var $js;
     if (match >= 32) {
-      var switcher = match - 34;
+      var switcher = match - 34 | 0;
       $js = switcher > 58 || switcher < 0 ? (
           switcher >= 93 ? 4 : 1
         ) : (
@@ -34,7 +34,7 @@ function escaped(s) {
           match >= 8 ? 2 : 4
         );
     }
-    n += $js;
+    n = n + $js | 0;
   }
   if (n === s.length) {
     return Bytes.copy(s);
@@ -73,17 +73,17 @@ function escaped(s) {
         switch (c) {
           case 8 : 
               s$prime[n] = /* "\\" */92;
-              ++ n;
+              n = n + 1 | 0;
               s$prime[n] = /* "b" */98;
               break;
           case 9 : 
               s$prime[n] = /* "\\" */92;
-              ++ n;
+              n = n + 1 | 0;
               s$prime[n] = /* "t" */116;
               break;
           case 10 : 
               s$prime[n] = /* "\\" */92;
-              ++ n;
+              n = n + 1 | 0;
               s$prime[n] = /* "n" */110;
               break;
           case 0 : 
@@ -100,7 +100,7 @@ function escaped(s) {
               break;
           case 13 : 
               s$prime[n] = /* "\\" */92;
-              ++ n;
+              n = n + 1 | 0;
               s$prime[n] = /* "r" */114;
               break;
           
@@ -109,21 +109,21 @@ function escaped(s) {
       switch (exit) {
         case 1 : 
             s$prime[n] = /* "\\" */92;
-            ++ n;
-            s$prime[n] = 48 + (c / 100 | 0);
-            ++ n;
-            s$prime[n] = 48 + (c / 10 | 0) % 10;
-            ++ n;
-            s$prime[n] = 48 + c % 10;
+            n = n + 1 | 0;
+            s$prime[n] = 48 + (c / 100 | 0) | 0;
+            n = n + 1 | 0;
+            s$prime[n] = 48 + (c / 10 | 0) % 10 | 0;
+            n = n + 1 | 0;
+            s$prime[n] = 48 + c % 10 | 0;
             break;
         case 2 : 
             s$prime[n] = /* "\\" */92;
-            ++ n;
+            n = n + 1 | 0;
             s$prime[n] = c;
             break;
         
       }
-      ++ n;
+      n = n + 1 | 0;
     }
     return s$prime;
   }
diff --git a/jscomp/test/complex_while_loop.js b/jscomp/test/complex_while_loop.js
index 86c1912f5e..bc7fdc491c 100644
--- a/jscomp/test/complex_while_loop.js
+++ b/jscomp/test/complex_while_loop.js
@@ -10,13 +10,13 @@ function f() {
             return 1;
           }
           else {
-            return fib(n - 1) + fib(n - 2);
+            return fib(n - 1) + fib(n - 2) | 0;
           }
         };
         return +(fib(n) > 10);
       }()) {
     console.log("" + n);
-    ++ n;
+    n = n + 1 | 0;
   };
   return /* () */0;
 }
@@ -24,7 +24,7 @@ function f() {
 function ff() {
   while(function () {
         var b = 9;
-        return +(3 + b > 10);
+        return +((3 + b | 0) > 10);
       }()) {
     
   };
diff --git a/jscomp/test/cont_int_fold_test.js b/jscomp/test/cont_int_fold_test.js
index 700c6c7e85..b9dea88c52 100644
--- a/jscomp/test/cont_int_fold_test.js
+++ b/jscomp/test/cont_int_fold_test.js
@@ -3,11 +3,11 @@
 
 
 function a(a0, a1, a2, a3, a4) {
-  return 1 + a0 + a1 + a2 + a3 + a4 + 2;
+  return (((((1 + a0 | 0) + a1 | 0) + a2 | 0) + a3 | 0) + a4 | 0) + 2 | 0;
 }
 
 function b(a0, a1, a2, a3, a4) {
-  return 1 + a0 + a1 + a2 + a3 + a4 + (1 + a0 + a1 + a2 + a3 + a4);
+  return (((((1 + a0 | 0) + a1 | 0) + a2 | 0) + a3 | 0) + a4 | 0) + (((((1 + a0 | 0) + a1 | 0) + a2 | 0) + a3 | 0) + a4 | 0) | 0;
 }
 
 exports.a = a;
diff --git a/jscomp/test/cps_test.js b/jscomp/test/cps_test.js
index 02beb9c676..ebe2f512c1 100644
--- a/jscomp/test/cps_test.js
+++ b/jscomp/test/cps_test.js
@@ -15,7 +15,7 @@ function test() {
       if (n) {
         _acc = (function(n,acc){
         return function () {
-          v[0] += n;
+          v[0] = v[0] + n | 0;
           return Caml_curry.app1(acc, /* () */0);
         }
         }(n,acc));
@@ -47,7 +47,7 @@ function test_closure() {
     }(i));
   }
   $$Array.iter(function (i) {
-        v[0] += Caml_curry.app1(i, 0);
+        v[0] = v[0] + Caml_curry.app1(i, 0) | 0;
         return /* () */0;
       }, arr);
   return v[0];
@@ -59,7 +59,7 @@ function test_closure2() {
         return x;
       });
   for(var i = 0; i<= 5; ++i){
-    var j = i + i;
+    var j = i + i | 0;
     arr[i] = (function(j){
     return function () {
       return j;
@@ -67,7 +67,7 @@ function test_closure2() {
     }(j));
   }
   $$Array.iter(function (i) {
-        v[0] += Caml_curry.app1(i, 0);
+        v[0] = v[0] + Caml_curry.app1(i, 0) | 0;
         return /* () */0;
       }, arr);
   return v[0];
diff --git a/jscomp/test/debugger_test.js b/jscomp/test/debugger_test.js
index 1734b55a43..09feaebfc0 100644
--- a/jscomp/test/debugger_test.js
+++ b/jscomp/test/debugger_test.js
@@ -7,7 +7,7 @@ function f(x, y) {
         x,
         y
       ]);
-  return x + y;
+  return x + y | 0;
 }
 
 function g() {
diff --git a/jscomp/test/demo_page.js b/jscomp/test/demo_page.js
index a2ce1b6217..dff0ad7b11 100644
--- a/jscomp/test/demo_page.js
+++ b/jscomp/test/demo_page.js
@@ -10,14 +10,14 @@ function fib(n) {
     return 1;
   }
   else {
-    return fib(n - 1) + fib(n - 2);
+    return fib(n - 1) + fib(n - 2) | 0;
   }
 }
 
 function sum(n) {
   var v = 0;
   for(var i = 0; i<= n; ++i){
-    v += i;
+    v = v + i | 0;
   }
   return v;
 }
@@ -37,11 +37,11 @@ function map(f, param) {
 }
 
 function test_curry(x, y) {
-  return x + y;
+  return x + y | 0;
 }
 
 function f(param) {
-  return 32 + param;
+  return 32 + param | 0;
 }
 
 ReactDom.render(React.createClass({
diff --git a/jscomp/test/ext_array.js b/jscomp/test/ext_array.js
index 75632b533b..af5bfbd715 100644
--- a/jscomp/test/ext_array.js
+++ b/jscomp/test/ext_array.js
@@ -13,9 +13,9 @@ function reverse_in_place(a) {
   var len = a.length;
   if (len) {
     for(var k = 0 ,k_finish = (len - 1) / 2 | 0; k<= k_finish; ++k){
-      var t = a$1[i + k];
-      a$1[i + k] = a$1[i + len - 1 - k];
-      a$1[i + len - 1 - k] = t;
+      var t = a$1[i + k | 0];
+      a$1[i + k | 0] = a$1[(i + len | 0) - 1 - k];
+      a$1[(i + len | 0) - 1 - k] = t;
     }
     return /* () */0;
   }
@@ -36,7 +36,7 @@ function reverse_of_list(l) {
       if (param) {
         a[len - i - 2] = param[0];
         _param = param[1];
-        _i = i + 1;
+        _i = i + 1 | 0;
         continue ;
         
       }
@@ -63,7 +63,7 @@ function filter(f, a) {
     else {
       var v = a[i];
       if (Caml_curry.app1(f, v)) {
-        _i = i + 1;
+        _i = i + 1 | 0;
         _acc = /* :: */[
           v,
           acc
@@ -72,7 +72,7 @@ function filter(f, a) {
         
       }
       else {
-        _i = i + 1;
+        _i = i + 1 | 0;
         continue ;
         
       }
@@ -93,7 +93,7 @@ function filter_map(f, a) {
     else {
       var v = a[i];
       var match = Caml_curry.app1(f, v);
-      _i = i + 1;
+      _i = i + 1 | 0;
       if (match) {
         _acc = /* :: */[
           match[0],
@@ -118,8 +118,8 @@ function range(from, to_) {
         ];
   }
   else {
-    return $$Array.init(to_ - from + 1, function (i) {
-                return i + from;
+    return $$Array.init(to_ - from + 1 | 0, function (i) {
+                return i + from | 0;
               });
   }
 }
diff --git a/jscomp/test/ext_bytes.js b/jscomp/test/ext_bytes.js
index 678eae03a4..fa2719387b 100644
--- a/jscomp/test/ext_bytes.js
+++ b/jscomp/test/ext_bytes.js
@@ -10,7 +10,7 @@ function escaped(s) {
     var match = s[i];
     var $js;
     if (match >= 32) {
-      var switcher = match - 34;
+      var switcher = match - 34 | 0;
       $js = switcher > 58 || switcher < 0 ? (
           switcher >= 93 ? 4 : 1
         ) : (
@@ -24,7 +24,7 @@ function escaped(s) {
           match >= 8 ? 2 : 4
         );
     }
-    n += $js;
+    n = n + $js | 0;
   }
   if (n === s.length) {
     return Bytes.copy(s);
@@ -63,17 +63,17 @@ function escaped(s) {
         switch (c) {
           case 8 : 
               s$prime[n] = /* "\\" */92;
-              ++ n;
+              n = n + 1 | 0;
               s$prime[n] = /* "b" */98;
               break;
           case 9 : 
               s$prime[n] = /* "\\" */92;
-              ++ n;
+              n = n + 1 | 0;
               s$prime[n] = /* "t" */116;
               break;
           case 10 : 
               s$prime[n] = /* "\\" */92;
-              ++ n;
+              n = n + 1 | 0;
               s$prime[n] = /* "n" */110;
               break;
           case 0 : 
@@ -90,7 +90,7 @@ function escaped(s) {
               break;
           case 13 : 
               s$prime[n] = /* "\\" */92;
-              ++ n;
+              n = n + 1 | 0;
               s$prime[n] = /* "r" */114;
               break;
           
@@ -99,21 +99,21 @@ function escaped(s) {
       switch (exit) {
         case 1 : 
             s$prime[n] = /* "\\" */92;
-            ++ n;
-            s$prime[n] = 48 + (c / 100 | 0);
-            ++ n;
-            s$prime[n] = 48 + (c / 10 | 0) % 10;
-            ++ n;
-            s$prime[n] = 48 + c % 10;
+            n = n + 1 | 0;
+            s$prime[n] = 48 + (c / 100 | 0) | 0;
+            n = n + 1 | 0;
+            s$prime[n] = 48 + (c / 10 | 0) % 10 | 0;
+            n = n + 1 | 0;
+            s$prime[n] = 48 + c % 10 | 0;
             break;
         case 2 : 
             s$prime[n] = /* "\\" */92;
-            ++ n;
+            n = n + 1 | 0;
             s$prime[n] = c;
             break;
         
       }
-      ++ n;
+      n = n + 1 | 0;
     }
     return s$prime;
   }
diff --git a/jscomp/test/ext_list.js b/jscomp/test/ext_list.js
index 0e5d150a82..dd7834d0b9 100644
--- a/jscomp/test/ext_list.js
+++ b/jscomp/test/ext_list.js
@@ -65,12 +65,12 @@ function filter_mapi(f, xs) {
         if (match) {
           return /* :: */[
                   match[0],
-                  aux(i + 1, ys)
+                  aux(i + 1 | 0, ys)
                 ];
         }
         else {
           _xs = ys;
-          _i = i + 1;
+          _i = i + 1 | 0;
           continue ;
           
         }
@@ -138,13 +138,13 @@ function filter_map2i(f, xs, ys) {
           if (match) {
             return /* :: */[
                     match[0],
-                    aux(i + 1, us, vs)
+                    aux(i + 1 | 0, us, vs)
                   ];
           }
           else {
             _ys = vs;
             _xs = us;
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             
           }
diff --git a/jscomp/test/ext_string.js b/jscomp/test/ext_string.js
index a509c210c8..d6511627c5 100644
--- a/jscomp/test/ext_string.js
+++ b/jscomp/test/ext_string.js
@@ -3,6 +3,7 @@
 
 var Bytes                   = require("../stdlib/bytes");
 var Caml_builtin_exceptions = require("../runtime/caml_builtin_exceptions");
+var Caml_primitive          = require("../runtime/caml_primitive");
 var Ext_bytes               = require("./ext_bytes");
 var $$String                = require("../stdlib/string");
 var Caml_curry              = require("../runtime/caml_curry");
@@ -27,7 +28,7 @@ function split_by($staropt$star, is_delim, str) {
     else if (Caml_curry.app1(is_delim, str.charCodeAt(pos))) {
       var new_len = last_pos - pos - 1;
       if (new_len !== 0 || keep_empty) {
-        var v = $$String.sub(str, pos + 1, new_len);
+        var v = $$String.sub(str, pos + 1 | 0, new_len);
         _pos = pos - 1;
         _last_pos = pos;
         _acc = /* :: */[
@@ -69,7 +70,7 @@ function starts_with(s, beg) {
   if (beg_len <= s_len) {
     var i = 0;
     while(i < beg_len && s[i] === beg[i]) {
-      ++ i;
+      i = i + 1 | 0;
     };
     return +(i === beg_len);
   }
@@ -116,13 +117,13 @@ function escaped(s) {
       else {
         var match = s.charCodeAt(i);
         if (match >= 32) {
-          var switcher = match - 34;
+          var switcher = match - 34 | 0;
           if (switcher > 58 || switcher < 0) {
             if (switcher >= 93) {
               return /* true */1;
             }
             else {
-              _i = i + 1;
+              _i = i + 1 | 0;
               continue ;
               
             }
@@ -131,7 +132,7 @@ function escaped(s) {
             return /* true */1;
           }
           else {
-            _i = i + 1;
+            _i = i + 1 | 0;
             continue ;
             
           }
@@ -159,7 +160,7 @@ function for_all(p, s) {
       return /* true */1;
     }
     else if (Caml_curry.app1(p, s.charCodeAt(i))) {
-      _i = i + 1;
+      _i = i + 1 | 0;
       continue ;
       
     }
@@ -175,9 +176,9 @@ function is_empty(s) {
 
 function repeat(n, s) {
   var len = s.length;
-  var res = Caml_string.caml_create_string(n * len);
-  for(var i = 0 ,i_finish = n - 1; i<= i_finish; ++i){
-    $$String.blit(s, 0, res, i * len, len);
+  var res = Caml_string.caml_create_string(Caml_primitive.imul(n, len));
+  for(var i = 0 ,i_finish = n - 1 | 0; i<= i_finish; ++i){
+    $$String.blit(s, 0, res, Caml_primitive.imul(i, len), len);
   }
   return Bytes.to_string(res);
 }
@@ -187,15 +188,15 @@ function equal(x, y) {
 }
 
 function _is_sub(sub, i, s, j, len) {
-  if (j + len <= s.length) {
+  if ((j + len | 0) <= s.length) {
     var _k = 0;
     while(true) {
       var k = _k;
       if (k === len) {
         return /* true */1;
       }
-      else if (sub[i + k] === s[j + k]) {
-        _k = k + 1;
+      else if (sub[i + k | 0] === s[j + k | 0]) {
+        _k = k + 1 | 0;
         continue ;
         
       }
@@ -220,11 +221,11 @@ function find($staropt$star, sub, s) {
     tag: 248
   };
   try {
-    while(i + n <= s.length) {
+    while((i + n | 0) <= s.length) {
       if (_is_sub(sub, 0, s, i, n)) {
         throw Exit;
       }
-      ++ i;
+      i = i + 1 | 0;
     };
     return -1;
   }
@@ -252,7 +253,7 @@ function rfind(sub, s) {
       if (_is_sub(sub, 0, s, i, n)) {
         throw Exit;
       }
-      -- i;
+      i = i - 1 | 0;
     };
     return -1;
   }
diff --git a/jscomp/test/fib.js b/jscomp/test/fib.js
index 901cfb9c30..657f9e1bdb 100644
--- a/jscomp/test/fib.js
+++ b/jscomp/test/fib.js
@@ -7,7 +7,7 @@ function fib(n) {
     return 1;
   }
   else {
-    return fib(n - 1) + fib(n - 2);
+    return fib(n - 1) + fib(n - 2) | 0;
   }
 }
 
@@ -23,8 +23,8 @@ function fib2(n) {
       return a;
     }
     else {
-      _i = i + 1;
-      _b = a + b;
+      _i = i + 1 | 0;
+      _b = a + b | 0;
       _a = b;
       continue ;
       
@@ -38,7 +38,7 @@ function fib3(n) {
   for(var i = 1; i<= n; ++i){
     var tmp = a;
     a = b;
-    b += tmp;
+    b = b + tmp | 0;
   }
   return a;
 }
diff --git a/jscomp/test/for_loop_test.js b/jscomp/test/for_loop_test.js
index d0f19f73b7..603fd7f1d2 100644
--- a/jscomp/test/for_loop_test.js
+++ b/jscomp/test/for_loop_test.js
@@ -1,10 +1,11 @@
 // Generated CODE, PLEASE EDIT WITH CARE
 'use strict';
 
-var Caml_array = require("../runtime/caml_array");
-var $$Array    = require("../stdlib/array");
-var Caml_curry = require("../runtime/caml_curry");
-var List       = require("../stdlib/list");
+var Caml_primitive = require("../runtime/caml_primitive");
+var Caml_array     = require("../runtime/caml_array");
+var $$Array        = require("../stdlib/array");
+var Caml_curry     = require("../runtime/caml_curry");
+var List           = require("../stdlib/list");
 
 function for_3(x) {
   var v = [0];
@@ -12,10 +13,10 @@ function for_3(x) {
         return /* () */0;
       }, x);
   for(var i = 0 ,i_finish = x.length - 1; i<= i_finish; ++i){
-    var j = i * 2;
+    var j = (i << 1);
     arr[i] = (function(j){
     return function () {
-      v[0] += j;
+      v[0] = v[0] + j | 0;
       return /* () */0;
     }
     }(j));
@@ -32,11 +33,11 @@ function for_4(x) {
         return /* () */0;
       }, x);
   for(var i = 0 ,i_finish = x.length - 1; i<= i_finish; ++i){
-    var j = i * 2;
-    var k = 2 * j;
+    var j = (i << 1);
+    var k = (j << 1);
     arr[i] = (function(k){
     return function () {
-      v[0] += k;
+      v[0] = v[0] + k | 0;
       return /* () */0;
     }
     }(k));
@@ -53,10 +54,10 @@ function for_5(x, u) {
         return /* () */0;
       }, x);
   for(var i = 0 ,i_finish = x.length - 1; i<= i_finish; ++i){
-    var k = 2 * u * u;
+    var k = Caml_primitive.imul((u << 1), u);
     arr[i] = (function(k){
     return function () {
-      v[0] += k;
+      v[0] = v[0] + k | 0;
       return /* () */0;
     }
     }(k));
@@ -75,18 +76,18 @@ function for_6(x, u) {
   var v4 = [0];
   var v5 = [0];
   var inspect_3 = -1;
-  ++ v4[0];
+  v4[0] = v4[0] + 1 | 0;
   for(var j = 0; j<= 1; ++j){
-    ++ v5[0];
+    v5[0] = v5[0] + 1 | 0;
     var v2 = [0];
     (function(v2){
     for(var i = 0 ,i_finish = x.length - 1; i<= i_finish; ++i){
-      var k = 2 * u * u;
-      var h = 2 * v5[0];
-      ++ v2[0];
+      var k = Caml_primitive.imul((u << 1), u);
+      var h = (v5[0] << 1);
+      v2[0] = v2[0] + 1 | 0;
       arr[i] = (function(k,h){
       return function () {
-        v[0] = v[0] + k + v2[0] + v4[0] + v5[0] + h + u;
+        v[0] = (((((v[0] + k | 0) + v2[0] | 0) + v4[0] | 0) + v5[0] | 0) + h | 0) + u | 0;
         return /* () */0;
       }
       }(k,h));
@@ -113,9 +114,9 @@ function for_7() {
   for(var i = 0; i<= 6; ++i){
     (function(i){
     for(var j = 0; j<= 2; ++j){
-      arr[i * 3 + j] = (function(j){
+      arr[Caml_primitive.imul(i, 3) + j | 0] = (function(j){
       return function () {
-        v[0] = v[0] + i + j;
+        v[0] = (v[0] + i | 0) + j | 0;
         return /* () */0;
       }
       }(j));
@@ -134,13 +135,13 @@ function for_8() {
         return /* () */0;
       });
   for(var i = 0; i<= 6; ++i){
-    var k = 2 * i;
+    var k = (i << 1);
     (function(i,k){
     for(var j = 0; j<= 2; ++j){
-      var h = i + j;
-      arr[i * 3 + j] = (function(j,h){
+      var h = i + j | 0;
+      arr[Caml_primitive.imul(i, 3) + j | 0] = (function(j,h){
       return function () {
-        v[0] = v[0] + i + j + h + k;
+        v[0] = (((v[0] + i | 0) + j | 0) + h | 0) + k | 0;
         return /* () */0;
       }
       }(j,h));
@@ -176,20 +177,20 @@ function for_9() {
       });
   for(var i = 0; i<= 1; ++i){
     var v$1 = [0];
-    v$1[0] += i;
+    v$1[0] = v$1[0] + i | 0;
     (function(v$1){
     for(var j = 0; j<= 1; ++j){
-      ++ v$1[0];
+      v$1[0] = v$1[0] + 1 | 0;
       Caml_curry.app1(collect, v$1[0]);
-      arr[i * 2 + j] = function () {
-        vv[0] += v$1[0];
+      arr[(i << 1) + j | 0] = function () {
+        vv[0] = vv[0] + v$1[0] | 0;
         return /* () */0;
       };
     }
     }(v$1));
     arr2[i] = (function(v$1){
     return function () {
-      vv2[0] += v$1[0];
+      vv2[0] = vv2[0] + v$1[0] | 0;
       return /* () */0;
     }
     }(v$1));
diff --git a/jscomp/test/format_regression.js b/jscomp/test/format_regression.js
index c7c3c875d2..69cd8aba9f 100644
--- a/jscomp/test/format_regression.js
+++ b/jscomp/test/format_regression.js
@@ -59,7 +59,7 @@ function advance_loop(state) {
     else {
       take_queue(state[/* pp_queue */3]);
       Caml_curry.app1(format_pp_token(state, size$1 < 0 ? 1000000010 : size$1), match[/* token */1]);
-      state[/* pp_left_total */1] = match[/* length */2] + state[/* pp_left_total */1];
+      state[/* pp_left_total */1] = match[/* length */2] + state[/* pp_left_total */1] | 0;
       continue ;
       
     }
diff --git a/jscomp/test/hashtbl_test.js b/jscomp/test/hashtbl_test.js
index 60839a40b0..218da761b9 100644
--- a/jscomp/test/hashtbl_test.js
+++ b/jscomp/test/hashtbl_test.js
@@ -31,10 +31,10 @@ function f() {
 function g(count) {
   var tbl = Hashtbl.create(/* None */0, 17);
   for(var i = 0; i<= count; ++i){
-    Hashtbl.replace(tbl, i * 2, "" + i);
+    Hashtbl.replace(tbl, (i << 1), "" + i);
   }
   for(var i$1 = 0; i$1<= count; ++i$1){
-    Hashtbl.replace(tbl, i$1 * 2, "" + i$1);
+    Hashtbl.replace(tbl, (i$1 << 1), "" + i$1);
   }
   var v = to_list(tbl);
   return $$Array.of_list(List.sort(function (param, param$1) {
@@ -73,7 +73,7 @@ var suites_001 = /* :: */[
       return /* Eq */{
               0: $$Array.init(1001, function (i) {
                     return /* tuple */[
-                            2 * i,
+                            (i << 1),
                             "" + i
                           ];
                   }),
diff --git a/jscomp/test/inline_edge_cases.js b/jscomp/test/inline_edge_cases.js
index 19a35df386..3815ba1130 100644
--- a/jscomp/test/inline_edge_cases.js
+++ b/jscomp/test/inline_edge_cases.js
@@ -11,7 +11,7 @@ function test3(_n) {
       
     }
     else {
-      return n + 9;
+      return (n + 5 | 0) + 4 | 0;
     }
   };
 }
@@ -25,7 +25,7 @@ function test2(_n) {
       
     }
     else {
-      return test3(n) + 3;
+      return test3(n) + 3 | 0;
     }
   };
 }
@@ -48,7 +48,7 @@ function test0(_n) {
           
         }
         else {
-          return test2(n$1) + 2;
+          return test2(n$1) + 2 | 0;
         }
       };
     }
@@ -57,7 +57,7 @@ function test0(_n) {
 
 var v = test0(10);
 
-test0(10) + 2;
+test0(10) + 2 | 0;
 
 exports.v = v;
 /* v Not a pure module */
diff --git a/jscomp/test/inline_map2_test.js b/jscomp/test/inline_map2_test.js
index 96d4d4a0ee..b14c737b73 100644
--- a/jscomp/test/inline_map2_test.js
+++ b/jscomp/test/inline_map2_test.js
@@ -25,7 +25,7 @@ function Make(Ord) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -44,7 +44,7 @@ function Make(Ord) {
   var bal = function (l, x, d, r) {
     var hl = l ? l[4] : 0;
     var hr = r ? r[4] : 0;
-    if (hl > hr + 2) {
+    if (hl > (hr + 2 | 0)) {
       if (l) {
         var lr = l[3];
         var ld = l[2];
@@ -70,7 +70,7 @@ function Make(Ord) {
             ];
       }
     }
-    else if (hr > hl + 2) {
+    else if (hr > (hl + 2 | 0)) {
       if (r) {
         var rr = r[3];
         var rd = r[2];
@@ -102,7 +102,7 @@ function Make(Ord) {
               1: x,
               2: d,
               3: r,
-              4: hl >= hr ? hl + 1 : hr + 1,
+              4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
               length: 5,
               tag: 0
             };
@@ -424,10 +424,10 @@ function Make(Ord) {
       if (r) {
         var rh = r[4];
         var lh = l[4];
-        if (lh > rh + 2) {
+        if (lh > (rh + 2 | 0)) {
           return bal(l[0], l[1], l[2], join(l[3], v, d, r));
         }
-        else if (rh > lh + 2) {
+        else if (rh > (lh + 2 | 0)) {
           return bal(join(l, v, d, r[0]), r[1], r[2], r[3]);
         }
         else {
@@ -685,7 +685,7 @@ function Make(Ord) {
   };
   var cardinal = function (param) {
     if (param) {
-      return cardinal(param[0]) + 1 + cardinal(param[3]);
+      return (cardinal(param[0]) + 1 | 0) + cardinal(param[3]) | 0;
     }
     else {
       return 0;
@@ -771,7 +771,7 @@ function create(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -792,7 +792,7 @@ function singleton(x, d) {
 function bal(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -818,7 +818,7 @@ function bal(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -850,7 +850,7 @@ function bal(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -1201,10 +1201,10 @@ function join(l, v, d, r) {
     if (r) {
       var rh = r[4];
       var lh = l[4];
-      if (lh > rh + 2) {
+      if (lh > (rh + 2 | 0)) {
         return bal(l[0], l[1], l[2], join(l[3], v, d, r));
       }
-      else if (rh > lh + 2) {
+      else if (rh > (lh + 2 | 0)) {
         return bal(join(l, v, d, r[0]), r[1], r[2], r[3]);
       }
       else {
@@ -1479,7 +1479,7 @@ function equal(cmp, m1, m2) {
 
 function cardinal(param) {
   if (param) {
-    return cardinal(param[0]) + 1 + cardinal(param[3]);
+    return (cardinal(param[0]) + 1 | 0) + cardinal(param[3]) | 0;
   }
   else {
     return 0;
@@ -1595,7 +1595,7 @@ function create$1(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -1616,7 +1616,7 @@ function singleton$1(x, d) {
 function bal$1(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -1642,7 +1642,7 @@ function bal$1(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -1674,7 +1674,7 @@ function bal$1(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -2025,10 +2025,10 @@ function join$1(l, v, d, r) {
     if (r) {
       var rh = r[4];
       var lh = l[4];
-      if (lh > rh + 2) {
+      if (lh > (rh + 2 | 0)) {
         return bal$1(l[0], l[1], l[2], join$1(l[3], v, d, r));
       }
-      else if (rh > lh + 2) {
+      else if (rh > (lh + 2 | 0)) {
         return bal$1(join$1(l, v, d, r[0]), r[1], r[2], r[3]);
       }
       else {
@@ -2301,7 +2301,7 @@ function equal$1(cmp, m1, m2) {
 
 function cardinal$1(param) {
   if (param) {
-    return cardinal$1(param[0]) + 1 + cardinal$1(param[3]);
+    return (cardinal$1(param[0]) + 1 | 0) + cardinal$1(param[3]) | 0;
   }
   else {
     return 0;
diff --git a/jscomp/test/inline_map_test.js b/jscomp/test/inline_map_test.js
index c744b46a29..f27fedc2a8 100644
--- a/jscomp/test/inline_map_test.js
+++ b/jscomp/test/inline_map_test.js
@@ -23,7 +23,7 @@ function create(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -32,7 +32,7 @@ function create(l, x, d, r) {
 function bal(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -58,7 +58,7 @@ function bal(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -90,7 +90,7 @@ function bal(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
diff --git a/jscomp/test/inline_regression_test.js b/jscomp/test/inline_regression_test.js
index 558c5cdad5..c2e06af824 100644
--- a/jscomp/test/inline_regression_test.js
+++ b/jscomp/test/inline_regression_test.js
@@ -24,14 +24,14 @@ function generic_basename(is_dir_sep, current_dir_name, name) {
       }
       else {
         var _n$1 = n;
-        var p = n + 1;
+        var p = n + 1 | 0;
         while(true) {
           var n$1 = _n$1;
           if (n$1 < 0) {
             return $$String.sub(name, 0, p);
           }
           else if (Caml_curry.app2(is_dir_sep, name, n$1)) {
-            return $$String.sub(name, n$1 + 1, p - n$1 - 1);
+            return $$String.sub(name, n$1 + 1 | 0, p - n$1 - 1);
           }
           else {
             _n$1 = n$1 - 1;
diff --git a/jscomp/test/int32_test.js b/jscomp/test/int32_test.js
index 5b4d2a5890..c512b7ae25 100644
--- a/jscomp/test/int32_test.js
+++ b/jscomp/test/int32_test.js
@@ -1,13 +1,14 @@
 // Generated CODE, PLEASE EDIT WITH CARE
 'use strict';
 
-var Pervasives = require("../stdlib/pervasives");
-var Mt         = require("./mt");
-var Int32      = require("../stdlib/int32");
-var $$Array    = require("../stdlib/array");
-var Caml_curry = require("../runtime/caml_curry");
-var Ext_array  = require("./ext_array");
-var Format     = require("../stdlib/format");
+var Pervasives     = require("../stdlib/pervasives");
+var Mt             = require("./mt");
+var Int32          = require("../stdlib/int32");
+var Caml_primitive = require("../runtime/caml_primitive");
+var $$Array        = require("../stdlib/array");
+var Caml_curry     = require("../runtime/caml_curry");
+var Ext_array      = require("./ext_array");
+var Format         = require("../stdlib/format");
 
 function f(x) {
   return /* tuple */[
@@ -151,7 +152,37 @@ var shift_left_tests = /* tuple */[
 
 var test_div = 30;
 
-Mt.from_pair_suites("int32_test.ml", Pervasives.$at(/* [] */0, Pervasives.$at($$Array.to_list(Ext_array.map2i(function (i, a, b) {
+function $star$tilde(prim, prim$1) {
+  return Caml_primitive.imul(prim, prim$1);
+}
+
+Mt.from_pair_suites("int32_test.ml", Pervasives.$at(/* :: */[
+          /* tuple */[
+            'File "int32_test.ml", line 32, characters 2-9',
+            function () {
+              return /* Eq */{
+                      0: 1,
+                      1: 1,
+                      length: 2,
+                      tag: 0
+                    };
+            }
+          ],
+          /* :: */[
+            /* tuple */[
+              'File "int32_test.ml", line 33, characters 2-9',
+              function () {
+                return /* Eq */{
+                        0: -2147483647,
+                        1: -2147483647,
+                        length: 2,
+                        tag: 0
+                      };
+              }
+            ],
+            /* [] */0
+          ]
+        ], Pervasives.$at($$Array.to_list(Ext_array.map2i(function (i, a, b) {
                       return /* tuple */[
                               Caml_curry.app1(Format.asprintf(/* Format */{
                                         0: /* String_literal */{
@@ -245,4 +276,5 @@ exports.shift_right_logical_tests = shift_right_logical_tests;
 exports.shift_right_tests         = shift_right_tests;
 exports.shift_left_tests          = shift_left_tests;
 exports.test_div                  = test_div;
+exports.$star$tilde               = $star$tilde;
 /* shift_right_logical_tests Not a pure module */
diff --git a/jscomp/test/int32_test.ml b/jscomp/test/int32_test.ml
index 5e11ab0410..b9fbdb3f5a 100644
--- a/jscomp/test/int32_test.ml
+++ b/jscomp/test/int32_test.ml
@@ -26,9 +26,11 @@ let shift_left_tests =
 
 let test_div = 61 / 2 
 
+let ( *~ ) = Int32.mul 
 
-;; Mt.from_pair_suites __FILE__ @@ [
-
+;; Mt.from_pair_suites __FILE__ @@ Mt.[
+  __LOC__, (fun _ -> Eq (0xffff_ffffl *~ 0xffff_ffffl, 1l));
+  __LOC__, (fun _ -> Eq (0xffff_ffffl *~ 0x7fff_ffffl, -2147483647l))
 ] @ ((let (a,b) = shift_right_logical_tests in    
                                    Ext_array.map2i (fun i a b -> Format.asprintf "shift_right_logical_cases %d" i, (fun _ -> Mt.Eq(a,b)) ) a b
                                    |>  Array.to_list))
diff --git a/jscomp/test/int_map.js b/jscomp/test/int_map.js
index 9fd623c797..b12217f322 100644
--- a/jscomp/test/int_map.js
+++ b/jscomp/test/int_map.js
@@ -22,7 +22,7 @@ function create(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -43,7 +43,7 @@ function singleton(x, d) {
 function bal(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -69,7 +69,7 @@ function bal(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -101,7 +101,7 @@ function bal(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -440,10 +440,10 @@ function join(l, v, d, r) {
     if (r) {
       var rh = r[4];
       var lh = l[4];
-      if (lh > rh + 2) {
+      if (lh > (rh + 2 | 0)) {
         return bal(l[0], l[1], l[2], join(l[3], v, d, r));
       }
-      else if (rh > lh + 2) {
+      else if (rh > (lh + 2 | 0)) {
         return bal(join(l, v, d, r[0]), r[1], r[2], r[3]);
       }
       else {
@@ -713,7 +713,7 @@ function equal(cmp, m1, m2) {
 
 function cardinal(param) {
   if (param) {
-    return cardinal(param[0]) + 1 + cardinal(param[3]);
+    return (cardinal(param[0]) + 1 | 0) + cardinal(param[3]) | 0;
   }
   else {
     return 0;
diff --git a/jscomp/test/int_overflow_test.js b/jscomp/test/int_overflow_test.js
index bfb2ed3621..353d5ea3cd 100644
--- a/jscomp/test/int_overflow_test.js
+++ b/jscomp/test/int_overflow_test.js
@@ -1,13 +1,14 @@
 // Generated CODE, PLEASE EDIT WITH CARE
 'use strict';
 
-var Mt    = require("./mt");
-var Int32 = require("../stdlib/int32");
+var Mt             = require("./mt");
+var Int32          = require("../stdlib/int32");
+var Caml_primitive = require("../runtime/caml_primitive");
 
 function hash_variant(s) {
   var accu = 0;
   for(var i = 0 ,i_finish = s.length - 1; i<= i_finish; ++i){
-    accu = 223 * accu + s.charCodeAt(i) & (1 << 31) - 1;
+    accu = Caml_primitive.imul(223, accu) + s.charCodeAt(i) & (1 << 31) - 1;
   }
   if (accu > 1073741823) {
     return accu - (1 << 31) | 0;
diff --git a/jscomp/test/js_obj_test.js b/jscomp/test/js_obj_test.js
index 208b558f73..ad8880fc1f 100644
--- a/jscomp/test/js_obj_test.js
+++ b/jscomp/test/js_obj_test.js
@@ -27,7 +27,7 @@ var suites_000 = /* tuple */[
       var $$class = CamlinternalOO.create_table(["say"]);
       var say = CamlinternalOO.get_method_label($$class, "say");
       CamlinternalOO.set_method($$class, say, function (_, x) {
-            return 1 + x;
+            return 1 + x | 0;
           });
       var env_init = function () {
         return CamlinternalOO.create_object_opt(0, $$class);
@@ -52,7 +52,7 @@ var suites_001 = /* :: */[
               0: 34,
               1: f({
                     "say": function (x) {
-                      return x + 2;
+                      return x + 2 | 0;
                     }
                   }),
               length: 2,
diff --git a/jscomp/test/lam_methname.js b/jscomp/test/lam_methname.js
index c2f7c06077..8c828a2419 100644
--- a/jscomp/test/lam_methname.js
+++ b/jscomp/test/lam_methname.js
@@ -44,7 +44,7 @@ function process(x) {
       }
       else {
         var len_sub = sub.length;
-        var indicator = Ext_string.tail_from(x, v + len_sub);
+        var indicator = Ext_string.tail_from(x, v + len_sub | 0);
         var normal_name = $$String.sub(x, 0, v);
         switch (indicator) {
           case "r" : 
diff --git a/jscomp/test/lazy_test.js b/jscomp/test/lazy_test.js
index 03a3f1e605..acd8fb7382 100644
--- a/jscomp/test/lazy_test.js
+++ b/jscomp/test/lazy_test.js
@@ -158,7 +158,7 @@ var l_from_fun = Lazy.from_fun(function () {
 var forward_test = {
   0: function () {
     var u = 3;
-    ++ u;
+    u = u + 1 | 0;
     return u;
   },
   length: 1,
diff --git a/jscomp/test/libqueue_test.js b/jscomp/test/libqueue_test.js
index 1b2d676145..01d0783fff 100644
--- a/jscomp/test/libqueue_test.js
+++ b/jscomp/test/libqueue_test.js
@@ -773,7 +773,7 @@ Queue.iter(function (j) {
               ]
             ];
       }
-      return ++ i$7[0];
+      return i$7[0] = i$7[0] + 1 | 0;
     }, q$5);
 
 var q1$1 = /* record */[
diff --git a/jscomp/test/loop_regression_test.js b/jscomp/test/loop_regression_test.js
index 4778c45828..b86ebe2f96 100644
--- a/jscomp/test/loop_regression_test.js
+++ b/jscomp/test/loop_regression_test.js
@@ -12,8 +12,8 @@ function f() {
       return acc[0];
     }
     else {
-      acc[0] += v[0];
-      ++ v[0];
+      acc[0] = acc[0] + v[0] | 0;
+      v[0] = v[0] + 1 | 0;
       continue ;
       
     }
diff --git a/jscomp/test/map_find_test.js b/jscomp/test/map_find_test.js
index ff812cb824..62e5641d44 100644
--- a/jscomp/test/map_find_test.js
+++ b/jscomp/test/map_find_test.js
@@ -24,7 +24,7 @@ function create(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -33,7 +33,7 @@ function create(l, x, d, r) {
 function bal(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -59,7 +59,7 @@ function bal(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -91,7 +91,7 @@ function bal(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -203,7 +203,7 @@ function create$1(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -212,7 +212,7 @@ function create$1(l, x, d, r) {
 function bal$1(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -238,7 +238,7 @@ function bal$1(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -270,7 +270,7 @@ function bal$1(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
diff --git a/jscomp/test/map_test.js b/jscomp/test/map_test.js
index c958103f0d..689b5ddd02 100644
--- a/jscomp/test/map_test.js
+++ b/jscomp/test/map_test.js
@@ -25,7 +25,7 @@ function create(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -34,7 +34,7 @@ function create(l, x, d, r) {
 function bal(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -60,7 +60,7 @@ function bal(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -92,7 +92,7 @@ function bal(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -238,7 +238,7 @@ function equal(cmp, m1, m2) {
 
 function cardinal(param) {
   if (param) {
-    return cardinal(param[0]) + 1 + cardinal(param[3]);
+    return (cardinal(param[0]) + 1 | 0) + cardinal(param[3]) | 0;
   }
   else {
     return 0;
@@ -262,7 +262,7 @@ function create$1(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -271,7 +271,7 @@ function create$1(l, x, d, r) {
 function bal$1(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -297,7 +297,7 @@ function bal$1(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -329,7 +329,7 @@ function bal$1(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
diff --git a/jscomp/test/obj_test.js b/jscomp/test/obj_test.js
index 93726a65c4..a1220b5850 100644
--- a/jscomp/test/obj_test.js
+++ b/jscomp/test/obj_test.js
@@ -26,7 +26,7 @@ var hello = ids[1];
 CamlinternalOO.set_methods($$class, /* array */[
       hi,
       function (_, x, y) {
-        return x + y;
+        return x + y | 0;
       },
       hello,
       function (self$neg1, z) {
@@ -92,7 +92,7 @@ var hello$1 = ids$2[3];
 CamlinternalOO.set_methods($$class$2, /* array */[
       hi$1,
       function (_, v, z) {
-        return v + z;
+        return v + z | 0;
       },
       id1,
       function () {
@@ -129,7 +129,7 @@ var $$class$4 = CamlinternalOO.create_table(["add"]);
 var add = CamlinternalOO.get_method_label($$class$4, "add");
 
 CamlinternalOO.set_method($$class$4, add, function (_, x, y) {
-      return x + y;
+      return x + y | 0;
     });
 
 CamlinternalOO.init_class($$class$4);
@@ -147,7 +147,7 @@ var add$1 = ids$3[1];
 CamlinternalOO.set_methods($$class$5, /* array */[
       add$1,
       function (_, x, y) {
-        return x + y;
+        return x + y | 0;
       },
       hi$2,
       function (self$neg6, x) {
diff --git a/jscomp/test/pr_regression_test.js b/jscomp/test/pr_regression_test.js
index 8bd3a495d4..f69ea6430b 100644
--- a/jscomp/test/pr_regression_test.js
+++ b/jscomp/test/pr_regression_test.js
@@ -7,7 +7,7 @@ var Caml_curry = require("../runtime/caml_curry");
 var v = [3];
 
 function f(h) {
-  ++ v[0];
+  v[0] = v[0] + 1 | 0;
   var partial_arg = 3;
   return function (param) {
     return Caml_curry.app2(h, partial_arg, param);
@@ -15,11 +15,11 @@ function f(h) {
 }
 
 f(function (prim, prim$1) {
-      return prim + prim$1;
+      return prim + prim$1 | 0;
     });
 
 f(function (prim, prim$1) {
-      return prim + prim$1;
+      return prim + prim$1 | 0;
     });
 
 var a = v[0];
@@ -27,7 +27,7 @@ var a = v[0];
 var v$1 = [3];
 
 function f$1(h) {
-  ++ v$1[0];
+  v$1[0] = v$1[0] + 1 | 0;
   var partial_arg = 3;
   return function (param) {
     return Caml_curry.app2(h, partial_arg, param);
@@ -35,11 +35,11 @@ function f$1(h) {
 }
 
 f$1(function (prim, prim$1) {
-      return prim + prim$1;
+      return prim + prim$1 | 0;
     });
 
 f$1(function (prim, prim$1) {
-      return prim + prim$1;
+      return prim + prim$1 | 0;
     });
 
 var b = v$1[0];
@@ -47,15 +47,15 @@ var b = v$1[0];
 var v$2 = [3];
 
 function f$2(h) {
-  return Caml_curry.app2(h, 2, (++ v$2[0], 3));
+  return Caml_curry.app2(h, 2, (v$2[0] = v$2[0] + 1 | 0, 3));
 }
 
 f$2(function (prim, prim$1) {
-      return prim + prim$1;
+      return prim + prim$1 | 0;
     });
 
 f$2(function (prim, prim$1) {
-      return prim + prim$1;
+      return prim + prim$1 | 0;
     });
 
 var c = v$2[0];
@@ -63,7 +63,7 @@ var c = v$2[0];
 var v$3 = [3];
 
 function f$3(h, _) {
-  ++ v$3[0];
+  v$3[0] = v$3[0] + 1 | 0;
   var partial_arg = 9;
   return function (param) {
     return Caml_curry.app2(h, partial_arg, param);
@@ -71,11 +71,11 @@ function f$3(h, _) {
 }
 
 f$3(function (prim, prim$1) {
-      return prim + prim$1;
+      return prim + prim$1 | 0;
     }, 3);
 
 f$3(function (prim, prim$1) {
-      return prim + prim$1;
+      return prim + prim$1 | 0;
     }, 3);
 
 var d = v$3[0];
diff --git a/jscomp/test/qcc.js b/jscomp/test/qcc.js
index 0fab3a6c05..44b70a7b4f 100644
--- a/jscomp/test/qcc.js
+++ b/jscomp/test/qcc.js
@@ -72,14 +72,14 @@ function find(s, _n) {
   while(true) {
     var n = _n;
     if (n >= syms[0]) {
-      ++ syms[0];
+      syms[0] = syms[0] + 1 | 0;
       return n;
     }
     else if (symtab[n] === s) {
       return n;
     }
     else {
-      _n = n + 1;
+      _n = n + 1 | 0;
       continue ;
       
     }
@@ -137,7 +137,7 @@ function getq() {
 }
 
 function isid(param) {
-  var switcher = param - 91;
+  var switcher = param - 91 | 0;
   if (switcher > 5 || switcher < 0) {
     if ((switcher + 26 >>> 0) > 57) {
       return /* false */0;
@@ -243,7 +243,7 @@ function next() {
                     };
             }
             else {
-              _n = 10 * n + Caml_curry.app1(getch, /* () */0) - 48;
+              _n = (Caml_primitive.imul(10, n) + Caml_curry.app1(getch, /* () */0) | 0) - 48;
               continue ;
               
             }
@@ -279,7 +279,7 @@ function next() {
         var match$2 = peekch(/* () */0);
         if (match$2 !== 34) {
           glo[e] = getq(/* () */0);
-          _e = e + 1;
+          _e = e + 1 | 0;
           continue ;
           
         }
@@ -287,7 +287,7 @@ function next() {
           Caml_curry.app1(getch, /* () */0);
           gpos[0] = e + 8 & -8;
           return /* SLit */{
-                  0: b + 4194536,
+                  0: (b + 232 | 0) + 4194304 | 0,
                   1: Bytes.to_string(Bytes.sub(glo, b, e - b)),
                   length: 2,
                   tag: 2
@@ -305,13 +305,13 @@ function next() {
           s[n$1] = ch$1;
           if (isid(peekch(/* () */0))) {
             _ch = Caml_curry.app1(getch, /* () */0);
-            _n$1 = n$1 + 1;
+            _n$1 = n$1 + 1 | 0;
             continue ;
             
           }
           else {
             return /* Sym */{
-                    0: Caml_curry.app1(addsym, Bytes.to_string(Bytes.sub(s, 0, n$1 + 1))),
+                    0: Caml_curry.app1(addsym, Bytes.to_string(Bytes.sub(s, 0, n$1 + 1 | 0))),
                     length: 1,
                     tag: 3
                   };
@@ -410,7 +410,7 @@ function out(x) {
   if (x !== 0) {
     out(x / 256 | 0);
     obuf[opos[0]] = Char.chr(x & 255);
-    return ++ opos[0];
+    return opos[0] = opos[0] + 1 | 0;
   }
   else {
     return 0;
@@ -419,15 +419,15 @@ function out(x) {
 
 function le(n, x) {
   for(var i = 0 ,i_finish = (n / 8 | 0) - 1; i<= i_finish; ++i){
-    var $$byte = (x >>> i * 8) & 255;
+    var $$byte = (x >>> (i << 3)) & 255;
     obuf[opos[0]] = Char.chr($$byte);
-    ++ opos[0];
+    opos[0] = opos[0] + 1 | 0;
   }
   return /* () */0;
 }
 
 function get32(l) {
-  return obuf[l] + obuf[l + 1] * 256 + obuf[l + 2] * 65536 + obuf[l + 3] * 16777216;
+  return ((obuf[l] + (obuf[l + 1 | 0] << 8) | 0) + (obuf[l + 2 | 0] << 16) | 0) + (obuf[l + 3 | 0] << 24) | 0;
 }
 
 function patch(rel, loc, n) {
@@ -444,7 +444,7 @@ function patch(rel, loc, n) {
   if (loc !== 0) {
     var i = opos[0];
     var loc$prime = get32(loc);
-    var x = rel ? n - (loc + 4) : n;
+    var x = rel ? n - (loc + 4 | 0) : n;
     if (dbg[0]) {
       Caml_curry.app3(Printf.eprintf(/* Format */{
                 0: /* String_literal */{
@@ -506,18 +506,18 @@ function patch(rel, loc, n) {
 }
 
 function load(r, n) {
-  out(184 + r);
+  out(184 + r | 0);
   return le(32, n);
 }
 
 function cmp(n) {
   load(0, 0);
-  return out(1020608 + (n << 8));
+  return out(1020608 + (n << 8) | 0);
 }
 
 function test(n, l) {
   out(4752832);
-  out(3972 + n);
+  out(3972 + n | 0);
   var loc = opos[0];
   le(32, l);
   return loc;
@@ -526,22 +526,22 @@ function test(n, l) {
 var align = [0];
 
 function push(r) {
-  ++ align[0];
+  align[0] = align[0] + 1 | 0;
   if (r < 8) {
-    return out(80 + r);
+    return out(80 + r | 0);
   }
   else {
-    return out(16720 + r - 8);
+    return out((16720 + r | 0) - 8);
   }
 }
 
 function pop(r) {
-  -- align[0];
+  align[0] = align[0] - 1 | 0;
   if (r < 8) {
-    return out(88 + r);
+    return out(88 + r | 0);
   }
   else {
-    return out(16728 + r - 8);
+    return out((16728 + r | 0) - 8);
   }
 }
 
@@ -1391,7 +1391,7 @@ function decl(g, _n, _stk) {
             var match = Caml_curry.app1(next$1, /* () */0);
             if (match.tag === 3) {
               var s = match[0];
-              var n$prime = n + 1;
+              var n$prime = n + 1 | 0;
               var stk$prime;
               if (g) {
                 var glo = globs[s];
@@ -1401,19 +1401,19 @@ function decl(g, _n, _stk) {
                         "symbol defined twice"
                       ];
                 }
-                var va = gpos[0] + 4194536;
+                var va = (gpos[0] + 232 | 0) + 4194304 | 0;
                 globs[s] = /* record */[
                   glo[/* loc */0],
                   va
                 ];
-                gpos[0] += 8;
+                gpos[0] = gpos[0] + 8 | 0;
                 stk$prime = stk;
               }
               else {
                 stk$prime = /* :: */[
                   /* tuple */[
                     s,
-                    top - 8 * n$prime
+                    top - (n$prime << 3)
                   ],
                   stk
                 ];
@@ -1474,14 +1474,14 @@ function decl(g, _n, _stk) {
                 }), n);
       }
       _stk = match[1];
-      _n = n + match[0];
+      _n = n + match[0] | 0;
       continue ;
       
     }
     else {
       Caml_curry.app1(unnext, t);
       if (!g && n !== 0) {
-        if (n * 8 >= 256) {
+        if ((n << 3) >= 256) {
           throw [
                 Caml_builtin_exceptions.assert_failure,
                 [
@@ -1492,8 +1492,8 @@ function decl(g, _n, _stk) {
               ];
         }
         out(4752364);
-        out(n * 8);
-        align[0] += n;
+        out((n << 3));
+        align[0] = align[0] + n | 0;
       }
       if (dbg[0] && !g) {
         console.error("end of blk decls");
@@ -1625,7 +1625,7 @@ function stmt(brk, stk) {
     }
     if (n !== 0) {
       out(4752324);
-      out(n * 8);
+      out((n << 3));
     }
     out(233);
     var loc$4 = opos[0];
@@ -1668,7 +1668,7 @@ function block(brk, stk) {
   Caml_curry.app1(next$1, /* () */0);
   if (n !== 0) {
     out(4752324);
-    out(n * 8);
+    out((n << 3));
     align[0] -= n;
     return /* () */0;
   }
@@ -1743,14 +1743,14 @@ function top(_param) {
                   }
                   var stk$prime_000 = /* tuple */[
                     match[0],
-                    -n * 8
+                    (-n << 3)
                   ];
                   var stk$prime = /* :: */[
                     stk$prime_000,
                     stk
                   ];
                   _stk = stk$prime;
-                  _n = n + 1;
+                  _n = n + 1 | 0;
                   _regs = List.tl(regs);
                   continue ;
                   
@@ -1882,8 +1882,8 @@ function elfphdr(ty, off, sz, align) {
   le(32, ty);
   le(32, 7);
   le(64, off);
-  le(64, off + 4194304);
-  le(64, off + 4194304);
+  le(64, off + 4194304 | 0);
+  le(64, off + 4194304 | 0);
   le(64, sz);
   le(64, sz);
   return le(64, align);
@@ -1905,7 +1905,7 @@ function elfgen(outf) {
   out(35271);
   load(0, 60);
   out(3845);
-  var off = 232 + gpos[0];
+  var off = 232 + gpos[0] | 0;
   var itr = function (f) {
     return Caml_curry.app1(symitr, function (i, s) {
                 var g = globs[i];
@@ -1918,7 +1918,7 @@ function elfgen(outf) {
               });
   };
   var va = function (x) {
-    return x + off + 4194304;
+    return (x + off | 0) + 4194304 | 0;
   };
   var patchloc = function (i, _) {
     var g = globs[i];
@@ -1934,25 +1934,25 @@ function elfgen(outf) {
   };
   Caml_curry.app1(symitr, patchloc);
   var strtab = opos[0];
-  ++ opos[0];
+  opos[0] = opos[0] + 1 | 0;
   var dllen = 37;
   $$String.blit("/lib64/ld-linux-x86-64.so.2\0libc.so.6", 0, obuf, opos[0], dllen);
-  opos[0] = opos[0] + dllen + 1;
+  opos[0] = (opos[0] + dllen | 0) + 1 | 0;
   itr(function (s, sl, _) {
         $$String.blit(s, 0, obuf, opos[0], sl);
-        opos[0] = opos[0] + sl + 1;
+        opos[0] = (opos[0] + sl | 0) + 1 | 0;
         return /* () */0;
       });
   opos[0] = opos[0] + 7 & -8;
   var symtab = opos[0];
-  var n = [dllen + 2];
-  opos[0] += 24;
+  var n = [dllen + 2 | 0];
+  opos[0] = opos[0] + 24 | 0;
   itr(function (_, sl, _$1) {
         le(32, n[0]);
         le(32, 16);
         le(64, 0);
         le(64, 0);
-        n[0] = n[0] + sl + 1;
+        n[0] = (n[0] + sl | 0) + 1 | 0;
         return /* () */0;
       });
   var rel = opos[0];
@@ -1963,7 +1963,7 @@ function elfgen(outf) {
             var l = _l;
             if (l !== 0) {
               le(64, va(l));
-              le(64, 1 + (n$1[0] << 32));
+              le(64, 1 + (n$1[0] << 32) | 0);
               le(64, 0);
               _l = get32(l);
               continue ;
@@ -1975,12 +1975,12 @@ function elfgen(outf) {
           };
         };
         genrel(l);
-        return ++ n$1[0];
+        return n$1[0] = n$1[0] + 1 | 0;
       });
   var hash = opos[0];
   var n$2 = ((rel - symtab) / 24 | 0) - 1;
   le(32, 1);
-  le(32, n$2 + 1);
+  le(32, n$2 + 1 | 0);
   le(32, n$2 > 0 ? 1 : 0);
   for(var i = 1; i<= n$2; ++i){
     le(32, i);
@@ -2052,9 +2052,9 @@ function elfgen(outf) {
   Bytes.blit(glo, 0, obuf, 232, gpos[0]);
   Bytes.blit(elfhdr, 0, obuf, 0, 64);
   opos[0] = 64;
-  elfphdr(3, strtab + 1 + off, 28, 1);
-  elfphdr(1, 0, tend + off, 2097152);
-  elfphdr(2, dyn + off, tend - dyn, 8);
+  elfphdr(3, (strtab + 1 | 0) + off | 0, 28, 1);
+  elfphdr(1, 0, tend + off | 0, 2097152);
+  elfphdr(2, dyn + off | 0, tend - dyn, 8);
   if (opos[0] !== 232) {
     throw [
           Caml_builtin_exceptions.assert_failure,
@@ -2066,7 +2066,7 @@ function elfgen(outf) {
         ];
   }
   patch(/* false */0, 24, va(entry));
-  return Pervasives.output_bytes(outf, Bytes.sub(obuf, 0, tend + off));
+  return Pervasives.output_bytes(outf, Bytes.sub(obuf, 0, tend + off | 0));
 }
 
 function main() {
diff --git a/jscomp/test/queue_test.js b/jscomp/test/queue_test.js
index 5b7fa88b77..5c12bdefa8 100644
--- a/jscomp/test/queue_test.js
+++ b/jscomp/test/queue_test.js
@@ -10,7 +10,7 @@ function to_array(q) {
   var v = Caml_array.caml_make_vect(q[/* length */0], 0);
   Queue.fold(function (i, e) {
         v[i] = e;
-        return i + 1;
+        return i + 1 | 0;
       }, 0, q);
   return v;
 }
diff --git a/jscomp/test/rec_module_test.js b/jscomp/test/rec_module_test.js
index 4f2454f666..00a17cd563 100644
--- a/jscomp/test/rec_module_test.js
+++ b/jscomp/test/rec_module_test.js
@@ -83,7 +83,7 @@ function even$1(n) {
 }
 
 function x() {
-  return Caml_curry.app1(BB[1], /* () */0) + 3;
+  return Caml_curry.app1(BB[1], /* () */0) + 3 | 0;
 }
 
 CamlinternalMod.update_mod([[
@@ -148,7 +148,7 @@ function create(l, v, r) {
           0: l,
           1: v,
           2: r,
-          3: hl >= hr ? hl + 1 : hr + 1,
+          3: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 4,
           tag: 0
         };
@@ -157,7 +157,7 @@ function create(l, v, r) {
 function bal(l, v, r) {
   var hl = l ? l[3] : 0;
   var hr = r ? r[3] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[2];
       var lv = l[1];
@@ -182,7 +182,7 @@ function bal(l, v, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[2];
       var rv = r[1];
@@ -212,7 +212,7 @@ function bal(l, v, r) {
             0: l,
             1: v,
             2: r,
-            3: hl >= hr ? hl + 1 : hr + 1,
+            3: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 4,
             tag: 0
           };
@@ -283,10 +283,10 @@ function join(l, v, r) {
     if (r) {
       var rh = r[3];
       var lh = l[3];
-      if (lh > rh + 2) {
+      if (lh > (rh + 2 | 0)) {
         return bal(l[0], l[1], join(l[2], v, r));
       }
-      else if (rh > lh + 2) {
+      else if (rh > (lh + 2 | 0)) {
         return bal(join(l, v, r[0]), r[1], r[2]);
       }
       else {
@@ -815,7 +815,7 @@ function partition(p, param) {
 
 function cardinal(param) {
   if (param) {
-    return cardinal(param[0]) + 1 + cardinal(param[2]);
+    return (cardinal(param[0]) + 1 | 0) + cardinal(param[2]) | 0;
   }
   else {
     return 0;
diff --git a/jscomp/test/rec_value_test.js b/jscomp/test/rec_value_test.js
index d2286252ba..4ed0122738 100644
--- a/jscomp/test/rec_value_test.js
+++ b/jscomp/test/rec_value_test.js
@@ -56,7 +56,7 @@ function naive(n) {
     return 1;
   }
   else {
-    return n + naive(n - 1) + naive(n - 2);
+    return (n + naive(n - 1) | 0) + naive(n - 2) | 0;
   }
 }
 
@@ -87,7 +87,7 @@ Caml_obj.caml_update_dummy(h, {
 
 function fib(n) {
   if (n > 3 || n < 0) {
-    return fib(n - 1) + fib(n - 2);
+    return fib(n - 1) + fib(n - 2) | 0;
   }
   else {
     switch (n) {
@@ -165,7 +165,7 @@ function fib2(n) {
     return 1;
   }
   else {
-    return fib2(n - 1) + fib2(n - 2);
+    return fib2(n - 1) + fib2(n - 2) | 0;
   }
 }
 
@@ -174,7 +174,7 @@ function fib3(n) {
     return 1;
   }
   else {
-    return fib3(n - 1) + fib3(n - 2);
+    return fib3(n - 1) + fib3(n - 2) | 0;
   }
 }
 
@@ -226,7 +226,7 @@ function sum(_acc, _n) {
     var acc = _acc;
     if (n > 0) {
       _n = n - 1;
-      _acc = acc + n;
+      _acc = acc + n | 0;
       continue ;
       
     }
diff --git a/jscomp/test/small_inline_test.js b/jscomp/test/small_inline_test.js
index f4520950f2..89a37fce15 100644
--- a/jscomp/test/small_inline_test.js
+++ b/jscomp/test/small_inline_test.js
@@ -30,7 +30,7 @@ function hello5(y, f) {
 function f(_x) {
   while(true) {
     var x = _x;
-    _x = x + 4;
+    _x = (((x + 1 | 0) + 1 | 0) + 1 | 0) + 1 | 0;
     continue ;
     
   };
@@ -40,7 +40,7 @@ function ff(_x, _y) {
   while(true) {
     var y = _y;
     var x = _x;
-    _y = x + 1;
+    _y = x + 1 | 0;
     _x = y;
     continue ;
     
diff --git a/jscomp/test/string_test.js b/jscomp/test/string_test.js
index 31e5bd6f0e..37fbfa4449 100644
--- a/jscomp/test/string_test.js
+++ b/jscomp/test/string_test.js
@@ -29,7 +29,7 @@ function ff(x) {
     default:
       a = 8;
   }
-  return a + 3;
+  return a + 3 | 0;
 }
 
 function gg(x) {
@@ -61,7 +61,7 @@ function gg(x) {
       
     }
   }
-  return a + 3;
+  return a + 3 | 0;
 }
 
 function rev_split_by_char(c, s) {
@@ -77,7 +77,7 @@ function rev_split_by_char(c, s) {
           s$prime,
           l
         ];
-      _i = i$prime + 1;
+      _i = i$prime + 1 | 0;
       continue ;
       
     }
@@ -122,7 +122,7 @@ function xsplit(delim, s) {
           }
         }
         if (exit === 1) {
-          var l_000 = $$String.sub(s, i$prime + 1, i - i$prime - 1);
+          var l_000 = $$String.sub(s, i$prime + 1 | 0, i - i$prime - 1);
           var l$1 = /* :: */[
             l_000,
             l
diff --git a/jscomp/test/tailcall_inline_test.js b/jscomp/test/tailcall_inline_test.js
index 05e23c53ea..f6d7bd8b7c 100644
--- a/jscomp/test/tailcall_inline_test.js
+++ b/jscomp/test/tailcall_inline_test.js
@@ -12,7 +12,7 @@ function f() {
       var acc = _acc;
       if (n > 0) {
         _n = n - 1;
-        _acc = acc + n;
+        _acc = acc + n | 0;
         continue ;
         
       }
diff --git a/jscomp/test/test_ari.js b/jscomp/test/test_ari.js
index 73253782d8..a078294d2f 100644
--- a/jscomp/test/test_ari.js
+++ b/jscomp/test/test_ari.js
@@ -8,12 +8,12 @@ var U          = require("U");
 
 function f(x) {
   return function (param) {
-    return x + param;
+    return x + param | 0;
   };
 }
 
 function f1(x, y) {
-  return x + y;
+  return x + y | 0;
 }
 
 function f3(g, x) {
@@ -21,7 +21,7 @@ function f3(g, x) {
 }
 
 function f2(param) {
-  return 3 + param;
+  return 3 + param | 0;
 }
 
 var g = 7;
@@ -38,7 +38,7 @@ function length_aux(_len, _param) {
     var len = _len;
     if (param) {
       _param = param[1];
-      _len = len + 1;
+      _len = len + 1 | 0;
       continue ;
       
     }
diff --git a/jscomp/test/test_array_primitive.js b/jscomp/test/test_array_primitive.js
index 2724e8c4c2..111564b5fe 100644
--- a/jscomp/test/test_array_primitive.js
+++ b/jscomp/test/test_array_primitive.js
@@ -6,7 +6,7 @@ var Caml_builtin_exceptions = require("../runtime/caml_builtin_exceptions");
 function caml_array_sub(x, offset, len) {
   var result = new Array(len);
   for(var j = 0 ,j_finish = len - 1; j<= j_finish; ++j){
-    result[j] = x[offset + j];
+    result[j] = x[offset + j | 0];
   }
   return result;
 }
diff --git a/jscomp/test/test_bug.js b/jscomp/test/test_bug.js
index f6943c9100..7d8fce621b 100644
--- a/jscomp/test/test_bug.js
+++ b/jscomp/test/test_bug.js
@@ -35,7 +35,7 @@ function escaped(s) {
     if (exit === 1) {
       $js = Caml_string.caml_is_printable(c) ? 1 : 4;
     }
-    n += $js;
+    n = n + $js | 0;
   }
   if (n === s.length) {
     return Bytes.copy(s);
@@ -46,26 +46,26 @@ function escaped(s) {
     for(var i$1 = 0 ,i_finish$1 = s.length - 1; i$1<= i_finish$1; ++i$1){
       var c$1 = s[i$1];
       var exit$1 = 0;
-      var switcher = c$1 - 34;
+      var switcher = c$1 - 34 | 0;
       if (switcher > 58 || switcher < 0) {
         if (switcher >= -20) {
           exit$1 = 1;
         }
         else {
-          switch (switcher + 34) {
+          switch (switcher + 34 | 0) {
             case 8 : 
                 s$prime[n] = /* "\\" */92;
-                ++ n;
+                n = n + 1 | 0;
                 s$prime[n] = /* "b" */98;
                 break;
             case 9 : 
                 s$prime[n] = /* "\\" */92;
-                ++ n;
+                n = n + 1 | 0;
                 s$prime[n] = /* "t" */116;
                 break;
             case 10 : 
                 s$prime[n] = /* "\\" */92;
-                ++ n;
+                n = n + 1 | 0;
                 s$prime[n] = /* "n" */110;
                 break;
             case 0 : 
@@ -82,7 +82,7 @@ function escaped(s) {
                 break;
             case 13 : 
                 s$prime[n] = /* "\\" */92;
-                ++ n;
+                n = n + 1 | 0;
                 s$prime[n] = /* "r" */114;
                 break;
             
@@ -91,7 +91,7 @@ function escaped(s) {
       }
       else if (switcher > 57 || switcher < 1) {
         s$prime[n] = /* "\\" */92;
-        ++ n;
+        n = n + 1 | 0;
         s$prime[n] = c$1;
       }
       else {
@@ -103,15 +103,15 @@ function escaped(s) {
         }
         else {
           s$prime[n] = /* "\\" */92;
-          ++ n;
-          s$prime[n] = 48 + (c$1 / 100 | 0);
-          ++ n;
-          s$prime[n] = 48 + (c$1 / 10 | 0) % 10;
-          ++ n;
-          s$prime[n] = 48 + c$1 % 10;
+          n = n + 1 | 0;
+          s$prime[n] = 48 + (c$1 / 100 | 0) | 0;
+          n = n + 1 | 0;
+          s$prime[n] = 48 + (c$1 / 10 | 0) % 10 | 0;
+          n = n + 1 | 0;
+          s$prime[n] = 48 + c$1 % 10 | 0;
         }
       }
-      ++ n;
+      n = n + 1 | 0;
     }
     return s$prime;
   }
diff --git a/jscomp/test/test_char.js b/jscomp/test/test_char.js
index 418595cda4..a7c8376d13 100644
--- a/jscomp/test/test_char.js
+++ b/jscomp/test/test_char.js
@@ -4,7 +4,7 @@
 var Caml_builtin_exceptions = require("../runtime/caml_builtin_exceptions");
 
 function f(x) {
-  return x + 1;
+  return x + 1 | 0;
 }
 
 function chr(n) {
@@ -21,7 +21,7 @@ function chr(n) {
 
 function lowercase(c) {
   if (c >= /* "A" */65 && c <= /* "Z" */90 || c >= /* "\192" */192 && c <= /* "\214" */214 || c >= /* "\216" */216 && c <= /* "\222" */222) {
-    return c + 32;
+    return c + 32 | 0;
   }
   else {
     return c;
diff --git a/jscomp/test/test_closure.js b/jscomp/test/test_closure.js
index 886b6a5e90..6d765953d9 100644
--- a/jscomp/test/test_closure.js
+++ b/jscomp/test/test_closure.js
@@ -15,7 +15,7 @@ function f() {
   for(var i = 0; i<= 9; ++i){
     arr[i] = (function(i){
     return function () {
-      v[0] += i;
+      v[0] = v[0] + i | 0;
       return /* () */0;
     }
     }(i));
diff --git a/jscomp/test/test_demo.js b/jscomp/test/test_demo.js
index eef42edd96..3a8832e76c 100644
--- a/jscomp/test/test_demo.js
+++ b/jscomp/test/test_demo.js
@@ -9,7 +9,7 @@ function fib(n) {
     return 1;
   }
   else {
-    return fib(n - 1) + fib(n - 2);
+    return fib(n - 1) + fib(n - 2) | 0;
   }
 }
 
@@ -39,26 +39,26 @@ function map(f, param) {
 function sum(n) {
   var v = 0;
   for(var i = 0; i<= n; ++i){
-    v += i;
+    v = v + i | 0;
   }
   return v;
 }
 
 function f(x, y, z) {
-  return x + y + z;
+  return (x + y | 0) + z | 0;
 }
 
 function g(x, y) {
-  var u = x + y;
+  var u = x + y | 0;
   return function (z) {
-    return u + z;
+    return u + z | 0;
   };
 }
 
 function g1(x, y) {
-  var u = x + y;
+  var u = x + y | 0;
   return function (xx, yy) {
-    return xx + yy + u;
+    return (xx + yy | 0) + u | 0;
   };
 }
 
diff --git a/jscomp/test/test_eq.js b/jscomp/test/test_eq.js
index f6ba2eebc9..31fad8ec71 100644
--- a/jscomp/test/test_eq.js
+++ b/jscomp/test/test_eq.js
@@ -3,7 +3,7 @@
 
 
 function f(x, y) {
-  return x + y;
+  return x + y | 0;
 }
 
 exports.f = f;
diff --git a/jscomp/test/test_export2.js b/jscomp/test/test_export2.js
index 92d95b7a63..01a75e3d6e 100644
--- a/jscomp/test/test_export2.js
+++ b/jscomp/test/test_export2.js
@@ -1,9 +1,10 @@
 // Generated CODE, PLEASE EDIT WITH CARE
 'use strict';
 
+var Caml_primitive = require("../runtime/caml_primitive");
 
 function f(x, y) {
-  return x * y;
+  return Caml_primitive.imul(x, y);
 }
 
 exports.f = f;
diff --git a/jscomp/test/test_fib.js b/jscomp/test/test_fib.js
index 166107a6c8..7986dc0174 100644
--- a/jscomp/test/test_fib.js
+++ b/jscomp/test/test_fib.js
@@ -8,7 +8,7 @@ function fib(n) {
     return 1;
   }
   else {
-    return fib(n - 1) + fib(n - 2);
+    return fib(n - 1) + fib(n - 2) | 0;
   }
 }
 
@@ -17,14 +17,14 @@ function fib2(n) {
     return 1;
   }
   else {
-    return fib2(n - 1) + fib2(n - 2);
+    return fib2(n - 1) + fib2(n - 2) | 0;
   }
 }
 
 var v = 0;
 
 for(var i = 0; i<= 10; ++i){
-  v += i;
+  v = v + i | 0;
 }
 
 var sum = v;
@@ -32,7 +32,7 @@ var sum = v;
 var v$1 = 0;
 
 for(var i$1 = 10; i$1>= 0; --i$1){
-  v$1 += i$1;
+  v$1 = v$1 + i$1 | 0;
 }
 
 var sumdown = v$1;
@@ -48,7 +48,7 @@ function cons(x, y) {
 
 function length(x) {
   if (x) {
-    return 1 + length(x[1]);
+    return 1 + length(x[1]) | 0;
   }
   else {
     return 0;
@@ -73,8 +73,8 @@ function f(x) {
   var v = x;
   var sum = 0;
   while(v > 0) {
-    sum += v;
-    -- v;
+    sum = sum + v | 0;
+    v = v - 1 | 0;
   };
   return sum;
 }
@@ -89,7 +89,7 @@ function fib3(n) {
     var a = _a;
     if (n$1 > 0) {
       _n = n$1 - 1;
-      _b = a + b;
+      _b = a + b | 0;
       _a = b;
       continue ;
       
diff --git a/jscomp/test/test_for_loop.js b/jscomp/test/test_for_loop.js
index 1498707450..e3c1285623 100644
--- a/jscomp/test/test_for_loop.js
+++ b/jscomp/test/test_for_loop.js
@@ -1,8 +1,9 @@
 // Generated CODE, PLEASE EDIT WITH CARE
 'use strict';
 
-var $$Array    = require("../stdlib/array");
-var Caml_curry = require("../runtime/caml_curry");
+var Caml_primitive = require("../runtime/caml_primitive");
+var $$Array        = require("../stdlib/array");
+var Caml_curry     = require("../runtime/caml_curry");
 
 function for_(x) {
   for(var i = 0 ,i_finish = (console.log("hi"), x.length); i<= i_finish; ++i){
@@ -24,10 +25,10 @@ function for_3(x) {
         return /* () */0;
       }, x);
   for(var i = 0 ,i_finish = x.length; i<= i_finish; ++i){
-    var j = i * 2;
+    var j = (i << 1);
     arr[i] = (function(j){
     return function () {
-      v[0] += j;
+      v[0] = v[0] + j | 0;
       return /* () */0;
     }
     }(j));
@@ -44,11 +45,11 @@ function for_4(x) {
         return /* () */0;
       }, x);
   for(var i = 0 ,i_finish = x.length; i<= i_finish; ++i){
-    var j = i * 2;
-    var k = 2 * j;
+    var j = (i << 1);
+    var k = (j << 1);
     arr[i] = (function(k){
     return function () {
-      v[0] += k;
+      v[0] = v[0] + k | 0;
       return /* () */0;
     }
     }(k));
@@ -65,10 +66,10 @@ function for_5(x, u) {
         return /* () */0;
       }, x);
   for(var i = 0 ,i_finish = x.length; i<= i_finish; ++i){
-    var k = 2 * u * u;
+    var k = Caml_primitive.imul((u << 1), u);
     arr[i] = (function(k){
     return function () {
-      v[0] += k;
+      v[0] = v[0] + k | 0;
       return /* () */0;
     }
     }(k));
@@ -86,18 +87,18 @@ function for_6(x, u) {
       }, x);
   var v4 = [0];
   var v5 = [0];
-  ++ v4[0];
+  v4[0] = v4[0] + 1 | 0;
   for(var j = 0; j<= 1; ++j){
-    ++ v5[0];
+    v5[0] = v5[0] + 1 | 0;
     var v2 = [0];
     (function(v2){
     for(var i = 0 ,i_finish = x.length; i<= i_finish; ++i){
-      var k = 2 * u * u;
-      var h = 2 * v5[0];
-      ++ v2[0];
+      var k = Caml_primitive.imul((u << 1), u);
+      var h = (v5[0] << 1);
+      v2[0] = v2[0] + 1 | 0;
       arr[i] = (function(k,h){
       return function () {
-        v[0] = v[0] + k + v2[0] + u + v4[0] + v5[0] + h;
+        v[0] = (((((v[0] + k | 0) + v2[0] | 0) + u | 0) + v4[0] | 0) + v5[0] | 0) + h | 0;
         return /* () */0;
       }
       }(k,h));
diff --git a/jscomp/test/test_for_map.js b/jscomp/test/test_for_map.js
index 5ba1591a57..171c755401 100644
--- a/jscomp/test/test_for_map.js
+++ b/jscomp/test/test_for_map.js
@@ -22,7 +22,7 @@ function create(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -43,7 +43,7 @@ function singleton(x, d) {
 function bal(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -69,7 +69,7 @@ function bal(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -101,7 +101,7 @@ function bal(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -440,10 +440,10 @@ function join(l, v, d, r) {
     if (r) {
       var rh = r[4];
       var lh = l[4];
-      if (lh > rh + 2) {
+      if (lh > (rh + 2 | 0)) {
         return bal(l[0], l[1], l[2], join(l[3], v, d, r));
       }
-      else if (rh > lh + 2) {
+      else if (rh > (lh + 2 | 0)) {
         return bal(join(l, v, d, r[0]), r[1], r[2], r[3]);
       }
       else {
@@ -713,7 +713,7 @@ function equal(cmp, m1, m2) {
 
 function cardinal(param) {
   if (param) {
-    return cardinal(param[0]) + 1 + cardinal(param[3]);
+    return (cardinal(param[0]) + 1 | 0) + cardinal(param[3]) | 0;
   }
   else {
     return 0;
diff --git a/jscomp/test/test_google_closure.js b/jscomp/test/test_google_closure.js
index dc227d879e..3c725b4425 100644
--- a/jscomp/test/test_google_closure.js
+++ b/jscomp/test/test_google_closure.js
@@ -4,12 +4,12 @@
 var $$Array = require("../stdlib/array");
 
 function f(a, b, _) {
-  return a + b;
+  return a + b | 0;
 }
 
 function f2(a) {
   return function () {
-    return a + 1;
+    return a + 1 | 0;
   };
 }
 
@@ -18,7 +18,7 @@ var arr = $$Array.init(2, function () {
     });
 
 for(var i = 0; i<= 2; ++i){
-  arr[i] = i + 1;
+  arr[i] = i + 1 | 0;
 }
 
 var match_000 = "" + 3;
diff --git a/jscomp/test/test_incomplete.js b/jscomp/test/test_incomplete.js
index 089b201ce7..4925092339 100644
--- a/jscomp/test/test_incomplete.js
+++ b/jscomp/test/test_incomplete.js
@@ -32,10 +32,10 @@ function f3(x) {
   switch (x.tag | 0) {
     case 0 : 
     case 2 : 
-        return x[0] + 1;
+        return x[0] + 1 | 0;
     case 1 : 
     case 3 : 
-        return x[0] + 2;
+        return x[0] + 2 | 0;
     
   }
 }
diff --git a/jscomp/test/test_incr_ref.js b/jscomp/test/test_incr_ref.js
index 2d22f5ff4b..349978bf77 100644
--- a/jscomp/test/test_incr_ref.js
+++ b/jscomp/test/test_incr_ref.js
@@ -4,7 +4,7 @@
 
 var u = 0;
 
-++ u;
+u = u + 1 | 0;
 
 var v = /* () */0;
 
diff --git a/jscomp/test/test_int_map_find.js b/jscomp/test/test_int_map_find.js
index ecdd775c9c..8eaea57496 100644
--- a/jscomp/test/test_int_map_find.js
+++ b/jscomp/test/test_int_map_find.js
@@ -22,7 +22,7 @@ function create(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -31,7 +31,7 @@ function create(l, x, d, r) {
 function bal(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -57,7 +57,7 @@ function bal(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -89,7 +89,7 @@ function bal(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
diff --git a/jscomp/test/test_internalOO.js b/jscomp/test/test_internalOO.js
index 77ef938219..adb6ded595 100644
--- a/jscomp/test/test_internalOO.js
+++ b/jscomp/test/test_internalOO.js
@@ -6,6 +6,7 @@ var Caml_obj                = require("../runtime/caml_obj");
 var Obj                     = require("../stdlib/obj");
 var Caml_oo                 = require("../runtime/caml_oo");
 var Sys                     = require("../stdlib/sys");
+var Caml_primitive          = require("../runtime/caml_primitive");
 var Caml_array              = require("../runtime/caml_array");
 var $$Array                 = require("../stdlib/array");
 var Caml_curry              = require("../runtime/caml_curry");
@@ -31,7 +32,7 @@ var dummy_item = /* () */0;
 function public_method_label(s) {
   var accu = 0;
   for(var i = 0 ,i_finish = s.length - 1; i<= i_finish; ++i){
-    accu = 223 * accu + s.charCodeAt(i);
+    accu = Caml_primitive.imul(223, accu) + s.charCodeAt(i) | 0;
   }
   accu = accu & (1 << 31) - 1;
   if (accu > 1073741823) {
@@ -59,7 +60,7 @@ function create(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -80,7 +81,7 @@ function singleton(x, d) {
 function bal(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -106,7 +107,7 @@ function bal(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -138,7 +139,7 @@ function bal(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -477,10 +478,10 @@ function join(l, v, d, r) {
     if (r) {
       var rh = r[4];
       var lh = l[4];
-      if (lh > rh + 2) {
+      if (lh > (rh + 2 | 0)) {
         return bal(l[0], l[1], l[2], join(l[3], v, d, r));
       }
-      else if (rh > lh + 2) {
+      else if (rh > (lh + 2 | 0)) {
         return bal(join(l, v, d, r[0]), r[1], r[2], r[3]);
       }
       else {
@@ -748,7 +749,7 @@ function equal(cmp, m1, m2) {
 
 function cardinal(param) {
   if (param) {
-    return cardinal(param[0]) + 1 + cardinal(param[3]);
+    return (cardinal(param[0]) + 1 | 0) + cardinal(param[3]) | 0;
   }
   else {
     return 0;
@@ -825,7 +826,7 @@ function create$1(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -846,7 +847,7 @@ function singleton$1(x, d) {
 function bal$1(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -872,7 +873,7 @@ function bal$1(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -904,7 +905,7 @@ function bal$1(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -1243,10 +1244,10 @@ function join$1(l, v, d, r) {
     if (r) {
       var rh = r[4];
       var lh = l[4];
-      if (lh > rh + 2) {
+      if (lh > (rh + 2 | 0)) {
         return bal$1(l[0], l[1], l[2], join$1(l[3], v, d, r));
       }
-      else if (rh > lh + 2) {
+      else if (rh > (lh + 2 | 0)) {
         return bal$1(join$1(l, v, d, r[0]), r[1], r[2], r[3]);
       }
       else {
@@ -1514,7 +1515,7 @@ function equal$1(cmp, m1, m2) {
 
 function cardinal$1(param) {
   if (param) {
-    return cardinal$1(param[0]) + 1 + cardinal$1(param[3]);
+    return (cardinal$1(param[0]) + 1 | 0) + cardinal$1(param[3]) | 0;
   }
   else {
     return 0;
@@ -1591,7 +1592,7 @@ function create$2(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -1612,7 +1613,7 @@ function singleton$2(x, d) {
 function bal$2(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -1638,7 +1639,7 @@ function bal$2(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -1670,7 +1671,7 @@ function bal$2(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -2009,10 +2010,10 @@ function join$2(l, v, d, r) {
     if (r) {
       var rh = r[4];
       var lh = l[4];
-      if (lh > rh + 2) {
+      if (lh > (rh + 2 | 0)) {
         return bal$2(l[0], l[1], l[2], join$2(l[3], v, d, r));
       }
-      else if (rh > lh + 2) {
+      else if (rh > (lh + 2 | 0)) {
         return bal$2(join$2(l, v, d, r[0]), r[1], r[2], r[3]);
       }
       else {
@@ -2282,7 +2283,7 @@ function equal$2(cmp, m1, m2) {
 
 function cardinal$2(param) {
   if (param) {
-    return cardinal$2(param[0]) + 1 + cardinal$2(param[3]);
+    return (cardinal$2(param[0]) + 1 | 0) + cardinal$2(param[3]) | 0;
   }
   else {
     return 0;
@@ -2362,18 +2363,18 @@ function fit_size(n) {
     return n;
   }
   else {
-    return fit_size((n + 1) / 2 | 0) * 2;
+    return (fit_size((n + 1 | 0) / 2 | 0) << 1);
   }
 }
 
 function new_table(pub_labels) {
-  ++ table_count[0];
+  table_count[0] = table_count[0] + 1 | 0;
   var len = pub_labels.length;
-  var methods = Caml_array.caml_make_vect(len * 2 + 2, dummy_met);
+  var methods = Caml_array.caml_make_vect((len << 1) + 2 | 0, dummy_met);
   methods[0] = len;
-  methods[1] = (fit_size(len) * Sys.word_size / 8 | 0) - 1;
+  methods[1] = (Caml_primitive.imul(fit_size(len), Sys.word_size) / 8 | 0) - 1;
   for(var i = 0 ,i_finish = len - 1; i<= i_finish; ++i){
-    methods[i * 2 + 3] = pub_labels[i];
+    methods[(i << 1) + 3 | 0] = pub_labels[i];
   }
   return /* record */[
           2,
@@ -2401,7 +2402,7 @@ function resize(array, new_size) {
 }
 
 function put(array, label, element) {
-  resize(array, label + 1);
+  resize(array, label + 1 | 0);
   array[/* methods */1][label] = element;
   return /* () */0;
 }
@@ -2412,7 +2413,7 @@ var inst_var_count = [0];
 
 function new_method(table) {
   var index = table[/* methods */1].length;
-  resize(table, index + 1);
+  resize(table, index + 1 | 0);
   return index;
 }
 
@@ -2440,7 +2441,7 @@ function get_method_labels(table, names) {
 }
 
 function set_method(table, label, element) {
-  ++ method_count[0];
+  method_count[0] = method_count[0] + 1 | 0;
   if (find$2(label, table[/* methods_by_label */3])) {
     return put(table, label, element);
   }
@@ -2573,7 +2574,7 @@ function widen(table) {
 
 function new_slot(table) {
   var index = table[/* size */0];
-  table[/* size */0] = index + 1;
+  table[/* size */0] = index + 1 | 0;
   return index;
 }
 
@@ -2608,12 +2609,12 @@ function new_methods_variables(table, meths, vals) {
   var meths$1 = to_array(meths);
   var nmeths = meths$1.length;
   var nvals = vals.length;
-  var res = Caml_array.caml_make_vect(nmeths + nvals, 0);
+  var res = Caml_array.caml_make_vect(nmeths + nvals | 0, 0);
   for(var i = 0 ,i_finish = nmeths - 1; i<= i_finish; ++i){
     res[i] = get_method_label(table, meths$1[i]);
   }
   for(var i$1 = 0 ,i_finish$1 = nvals - 1; i$1<= i_finish$1; ++i$1){
-    res[i$1 + nmeths] = new_variable(table, vals[i$1]);
+    res[i$1 + nmeths | 0] = new_variable(table, vals[i$1]);
   }
   return res;
 }
@@ -2658,7 +2659,7 @@ function create_table(public_methods) {
     var tags = $$Array.map(public_method_label, public_methods);
     var table = new_table(tags);
     $$Array.iteri(function (i, met) {
-          var lab = i * 2 + 2;
+          var lab = (i << 1) + 2 | 0;
           table[/* methods_by_name */2] = add$1(met, lab, table[/* methods_by_name */2]);
           table[/* methods_by_label */3] = add$2(lab, /* true */1, table[/* methods_by_label */3]);
           return /* () */0;
@@ -2671,9 +2672,9 @@ function create_table(public_methods) {
 }
 
 function init_class(table) {
-  inst_var_count[0] = inst_var_count[0] + table[/* size */0] - 1;
+  inst_var_count[0] = (inst_var_count[0] + table[/* size */0] | 0) - 1;
   table[/* initializers */7] = List.rev(table[/* initializers */7]);
-  return resize(table, 3 + (table[/* methods */1][1] * 16 / Sys.word_size | 0));
+  return resize(table, 3 + ((table[/* methods */1][1] << 4) / Sys.word_size | 0) | 0);
 }
 
 function inherits(cla, vals, virt_meths, concr_meths, param, top) {
@@ -3013,14 +3014,14 @@ function send_meth(m, n, _) {
 
 function new_cache(table) {
   var n = new_method(table);
-  var n$1 = n % 2 === 0 || n > 2 + (table[/* methods */1][1] * 16 / Sys.word_size | 0) ? n : new_method(table);
+  var n$1 = n % 2 === 0 || n > (2 + ((table[/* methods */1][1] << 4) / Sys.word_size | 0) | 0) ? n : new_method(table);
   table[/* methods */1][n$1] = 0;
   return n$1;
 }
 
 function method_impl(table, i, arr) {
   var next = function () {
-    ++ i[0];
+    i[0] = i[0] + 1 | 0;
     return arr[i[0]];
   };
   var clo = next(/* () */0);
@@ -3157,7 +3158,7 @@ function set_methods(table, methods) {
     var label = methods[i[0]];
     var clo = method_impl(table, i, methods);
     set_method(table, label, clo);
-    ++ i[0];
+    i[0] = i[0] + 1 | 0;
   };
   return /* () */0;
 }
diff --git a/jscomp/test/test_list.js b/jscomp/test/test_list.js
index 9e93b09910..2350efc5af 100644
--- a/jscomp/test/test_list.js
+++ b/jscomp/test/test_list.js
@@ -13,7 +13,7 @@ function length_aux(_len, _param) {
     var len = _len;
     if (param) {
       _param = param[1];
-      _len = len + 1;
+      _len = len + 1 | 0;
       continue ;
       
     }
@@ -135,7 +135,7 @@ function mapi(i, f, param) {
     var r = Caml_curry.app2(f, i, param[0]);
     return /* :: */[
             r,
-            mapi(i + 1, f, param[1])
+            mapi(i + 1 | 0, f, param[1])
           ];
   }
   else {
@@ -193,7 +193,7 @@ function iteri(f, l) {
     if (param) {
       Caml_curry.app2(f$1, i, param[0]);
       _param = param[1];
-      _i = i + 1;
+      _i = i + 1 | 0;
       continue ;
       
     }
diff --git a/jscomp/test/test_nested_print.js b/jscomp/test/test_nested_print.js
index f7ec2a130b..d9d0d4692e 100644
--- a/jscomp/test/test_nested_print.js
+++ b/jscomp/test/test_nested_print.js
@@ -4,12 +4,12 @@
 var Caml_curry = require("../runtime/caml_curry");
 
 function u(_, x) {
-  return x + x;
+  return x + x | 0;
 }
 
 function f(g, x) {
   var u = Caml_curry.app1(g, x);
-  return u + u;
+  return u + u | 0;
 }
 
 exports.u = u;
diff --git a/jscomp/test/test_order_tailcall.js b/jscomp/test/test_order_tailcall.js
index 366dd12318..8dc302ba2d 100644
--- a/jscomp/test/test_order_tailcall.js
+++ b/jscomp/test/test_order_tailcall.js
@@ -25,7 +25,7 @@ function f1(_x, _y, _z) {
 function f2(_, _y) {
   while(true) {
     var y = _y;
-    _y = y + 10;
+    _y = y + 10 | 0;
     continue ;
     
   };
@@ -35,7 +35,7 @@ function f3(_x, _y) {
   while(true) {
     var y = _y;
     var x = _x;
-    _y = x + 10;
+    _y = x + 10 | 0;
     _x = y;
     continue ;
     
@@ -46,8 +46,8 @@ function f4(_x, _y) {
   while(true) {
     var y = _y;
     var x = _x;
-    _y = y + x;
-    _x = x + 10;
+    _y = y + x | 0;
+    _x = x + 10 | 0;
     continue ;
     
   };
@@ -56,8 +56,8 @@ function f4(_x, _y) {
 function f5(_x, _y, z) {
   while(true) {
     var y = _y;
-    _y = z + 20;
-    _x = y + 10;
+    _y = z + 20 | 0;
+    _x = y + 10 | 0;
     continue ;
     
   };
@@ -116,7 +116,7 @@ function f8(_x, _y) {
     var y = _y;
     var x = _x;
     if (x > 10) {
-      _y = y + 1;
+      _y = y + 1 | 0;
       continue ;
       
     }
@@ -131,7 +131,7 @@ function f8(_x, _y) {
       
     }
     else {
-      return f8(x, y + 1) + f8(x - 1, y);
+      return f8(x, y + 1 | 0) + f8(x - 1, y) | 0;
     }
   };
 }
diff --git a/jscomp/test/test_per.js b/jscomp/test/test_per.js
index 2c6f49387b..2b23055fc9 100644
--- a/jscomp/test/test_per.js
+++ b/jscomp/test/test_per.js
@@ -64,12 +64,12 @@ function lnot(x) {
 
 var max_int = 2147483647;
 
-var min_int = max_int + 1;
+var min_int = max_int + 1 | 0;
 
 function $caret(s1, s2) {
   var l1 = s1.length;
   var l2 = s2.length;
-  var s = Caml_string.caml_create_string(l1 + l2);
+  var s = Caml_string.caml_create_string(l1 + l2 | 0);
   Caml_string.caml_blit_string(s1, 0, s, 0, l1);
   Caml_string.caml_blit_string(s2, 0, s, l1, l2);
   return s;
@@ -129,7 +129,7 @@ function valid_float_lexem(s) {
           return s;
         }
         else {
-          _i = i + 1;
+          _i = i + 1 | 0;
           continue ;
           
         }
@@ -138,7 +138,7 @@ function valid_float_lexem(s) {
         return s;
       }
       else {
-        _i = i + 1;
+        _i = i + 1 | 0;
         continue ;
         
       }
@@ -328,7 +328,7 @@ function unsafe_really_input(ic, s, _ofs, _len) {
       var r = Caml_primitive.caml_ml_input(ic, s, ofs, len);
       if (r) {
         _len = len - r;
-        _ofs = ofs + r;
+        _ofs = ofs + r | 0;
         continue ;
         
       }
@@ -388,7 +388,7 @@ function input_line(chan) {
         Caml_primitive.caml_ml_input(chan, res, 0, n - 1);
         Caml_io.caml_ml_input_char(chan);
         if (accu) {
-          var len$1 = len + n - 1;
+          var len$1 = (len + n | 0) - 1;
           return build_result(Caml_string.caml_create_string(len$1), len$1, /* :: */[
                       res,
                       accu
diff --git a/jscomp/test/test_primitive.js b/jscomp/test/test_primitive.js
index b9b3a4f148..6574239a5e 100644
--- a/jscomp/test/test_primitive.js
+++ b/jscomp/test/test_primitive.js
@@ -94,7 +94,7 @@ function fib(n) {
   else {
     var fib1 = fib(n - 1);
     var fib2 = fib(n - 2);
-    return fib1 + fib2 + 3;
+    return (fib1 + fib2 | 0) + 3 | 0;
   }
 }
 
diff --git a/jscomp/test/test_ramification.js b/jscomp/test/test_ramification.js
index 31851f01fc..d4204aae4f 100644
--- a/jscomp/test/test_ramification.js
+++ b/jscomp/test/test_ramification.js
@@ -22,13 +22,13 @@ function ff(x) {
     default:
       a = 8;
   }
-  return a + 3;
+  return a + 3 | 0;
 }
 
 function f(x) {
   var y;
   y = x.tag ? 4 : 3;
-  return y + 32;
+  return y + 32 | 0;
 }
 
 function f2(x) {
@@ -37,13 +37,13 @@ function f2(x) {
   v = 1;
   if (x.tag) {
     var z = 33;
-    y = z + 4;
+    y = z + 4 | 0;
   }
   else {
     var z$1 = 33;
-    y = z$1 + 3;
+    y = z$1 + 3 | 0;
   }
-  return y + 32;
+  return y + 32 | 0;
 }
 
 function f3(x) {
@@ -56,7 +56,7 @@ function f3(x) {
   else {
     y = 3;
   }
-  return y + 32;
+  return y + 32 | 0;
 }
 
 exports.ff = ff;
diff --git a/jscomp/test/test_set.js b/jscomp/test/test_set.js
index ca1ce86911..187fa69cda 100644
--- a/jscomp/test/test_set.js
+++ b/jscomp/test/test_set.js
@@ -21,7 +21,7 @@ function Make(Ord) {
             0: l,
             1: v,
             2: r,
-            3: hl >= hr ? hl + 1 : hr + 1,
+            3: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 4,
             tag: 0
           };
@@ -29,7 +29,7 @@ function Make(Ord) {
   var bal = function (l, v, r) {
     var hl = l ? l[3] : 0;
     var hr = r ? r[3] : 0;
-    if (hl > hr + 2) {
+    if (hl > (hr + 2 | 0)) {
       if (l) {
         var lr = l[2];
         var lv = l[1];
@@ -54,7 +54,7 @@ function Make(Ord) {
             ];
       }
     }
-    else if (hr > hl + 2) {
+    else if (hr > (hl + 2 | 0)) {
       if (r) {
         var rr = r[2];
         var rv = r[1];
@@ -84,7 +84,7 @@ function Make(Ord) {
               0: l,
               1: v,
               2: r,
-              3: hl >= hr ? hl + 1 : hr + 1,
+              3: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
               length: 4,
               tag: 0
             };
@@ -150,10 +150,10 @@ function Make(Ord) {
       if (r) {
         var rh = r[3];
         var lh = l[3];
-        if (lh > rh + 2) {
+        if (lh > (rh + 2 | 0)) {
           return bal(l[0], l[1], join(l[2], v, r));
         }
-        else if (rh > lh + 2) {
+        else if (rh > (lh + 2 | 0)) {
           return bal(join(l, v, r[0]), r[1], r[2]);
         }
         else {
@@ -661,7 +661,7 @@ function Make(Ord) {
   };
   var cardinal = function (param) {
     if (param) {
-      return cardinal(param[0]) + 1 + cardinal(param[2]);
+      return (cardinal(param[0]) + 1 | 0) + cardinal(param[2]) | 0;
     }
     else {
       return 0;
diff --git a/jscomp/test/test_side_effect_functor.js b/jscomp/test/test_side_effect_functor.js
index 0b21da3579..c2050b87de 100644
--- a/jscomp/test/test_side_effect_functor.js
+++ b/jscomp/test/test_side_effect_functor.js
@@ -4,7 +4,7 @@
 
 var v = 0;
 
-++ v;
+v = v + 1 | 0;
 
 console.log("" + v);
 
diff --git a/jscomp/test/test_simple_obj.js b/jscomp/test/test_simple_obj.js
index 5809b9208d..3a38096513 100644
--- a/jscomp/test/test_simple_obj.js
+++ b/jscomp/test/test_simple_obj.js
@@ -32,7 +32,7 @@ var hello = ids[3];
 CamlinternalOO.set_methods($$class, /* array */[
       hi,
       function (_, v, z) {
-        return v + z;
+        return v + z | 0;
       },
       id1,
       function () {
@@ -69,7 +69,7 @@ var $$class$2 = CamlinternalOO.create_table(shared);
 var add = CamlinternalOO.get_method_label($$class$2, "add");
 
 CamlinternalOO.set_method($$class$2, add, function (_, x, y) {
-      return x + y;
+      return x + y | 0;
     });
 
 CamlinternalOO.init_class($$class$2);
@@ -81,7 +81,7 @@ var $$class$3 = CamlinternalOO.create_table(shared);
 var add$1 = CamlinternalOO.get_method_label($$class$3, "add");
 
 CamlinternalOO.set_method($$class$3, add$1, function (_, x, y) {
-      return x + y;
+      return x + y | 0;
     });
 
 CamlinternalOO.init_class($$class$3);
diff --git a/jscomp/test/test_simple_ref.js b/jscomp/test/test_simple_ref.js
index b1cf383aaa..0a2dd2abb6 100644
--- a/jscomp/test/test_simple_ref.js
+++ b/jscomp/test/test_simple_ref.js
@@ -6,7 +6,7 @@ var Caml_curry = require("../runtime/caml_curry");
 var v = [0];
 
 function gen() {
-  ++ v[0];
+  v[0] = v[0] + 1 | 0;
   return v[0];
 }
 
diff --git a/jscomp/test/test_simple_tailcall.js b/jscomp/test/test_simple_tailcall.js
index 9fbce42541..3583466aee 100644
--- a/jscomp/test/test_simple_tailcall.js
+++ b/jscomp/test/test_simple_tailcall.js
@@ -11,7 +11,7 @@ function tailcall() {
 
 function non_length(x) {
   if (x) {
-    return 1 + non_length(x[1]);
+    return 1 + non_length(x[1]) | 0;
   }
   else {
     return 0;
@@ -25,11 +25,11 @@ function length(_acc, _x) {
     if (x) {
       var tl = x[1];
       if (tl) {
-        return 1 + length(acc + 1, tl[1]);
+        return 1 + length(acc + 1 | 0, tl[1]) | 0;
       }
       else {
         _x = tl;
-        _acc = acc + 1;
+        _acc = acc + 1 | 0;
         continue ;
         
       }
diff --git a/jscomp/test/test_string_map.js b/jscomp/test/test_string_map.js
index 0d8228e767..97c2dc23a4 100644
--- a/jscomp/test/test_string_map.js
+++ b/jscomp/test/test_string_map.js
@@ -22,7 +22,7 @@ function create(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -31,7 +31,7 @@ function create(l, x, d, r) {
 function bal(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -57,7 +57,7 @@ function bal(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -89,7 +89,7 @@ function bal(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
diff --git a/jscomp/test/test_tuple.js b/jscomp/test/test_tuple.js
index ca0c9f0f7f..258f38cc22 100644
--- a/jscomp/test/test_tuple.js
+++ b/jscomp/test/test_tuple.js
@@ -1,6 +1,7 @@
 // Generated CODE, PLEASE EDIT WITH CARE
 'use strict';
 
+var Caml_primitive = require("../runtime/caml_primitive");
 
 var r = 0;
 
@@ -8,12 +9,12 @@ for(var k = 1; k<= 10; ++k){
   for(var i = 1; i<= 10; ++i){
     var match = i % 2 ? /* tuple */[
         2,
-        i * 3
+        Caml_primitive.imul(i, 3)
       ] : /* tuple */[
         1,
-        i * 2
+        (i << 1)
       ];
-    r = r * match[0] + match[1];
+    r = Caml_primitive.imul(r, match[0]) + match[1] | 0;
   }
 }
 
diff --git a/jscomp/test/test_u.js b/jscomp/test/test_u.js
index f620d6b8d4..e0f1a6f459 100644
--- a/jscomp/test/test_u.js
+++ b/jscomp/test/test_u.js
@@ -6,8 +6,8 @@ function f(x) {
   var v = x;
   var sum = 0;
   while(v > 0) {
-    sum += v;
-    -- v;
+    sum = sum + v | 0;
+    v = v - 1 | 0;
   };
   return sum;
 }
diff --git a/jscomp/test/test_while_closure.js b/jscomp/test/test_while_closure.js
index 482ad1a2ef..a3d09da909 100644
--- a/jscomp/test/test_while_closure.js
+++ b/jscomp/test/test_while_closure.js
@@ -18,11 +18,11 @@ function f() {
     var j = n;
     arr[j] = (function(j){
     return function () {
-      v[0] += j;
+      v[0] = v[0] + j | 0;
       return /* () */0;
     }
     }(j));
-    ++ n;
+    n = n + 1 | 0;
   };
   return /* () */0;
 }
diff --git a/jscomp/test/test_while_side_effect.js b/jscomp/test/test_while_side_effect.js
index accc08ca90..a019b19cc9 100644
--- a/jscomp/test/test_while_side_effect.js
+++ b/jscomp/test/test_while_side_effect.js
@@ -4,7 +4,7 @@
 
 var v = [0];
 
-while(console.log("" + v[0]), ++ v[0], +(v[0] < 10)) {
+while(console.log("" + v[0]), v[0] = v[0] + 1 | 0, +(v[0] < 10)) {
   
 };
 
@@ -13,7 +13,7 @@ function fib(n) {
     return 1;
   }
   else {
-    return fib(n - 1) + fib(n - 2);
+    return fib(n - 1) + fib(n - 2) | 0;
   }
 }
 
@@ -22,9 +22,9 @@ var x = [3];
 while(function () {
       var y = 3;
       console.log("" + x[0]);
-      ++ y;
-      ++ x[0];
-      return +(fib(x[0]) + fib(x[0]) < 20);
+      y = y + 1 | 0;
+      x[0] = x[0] + 1 | 0;
+      return +((fib(x[0]) + fib(x[0]) | 0) < 20);
     }()) {
   console.log("" + 3);
 };
diff --git a/jscomp/test/test_zero_nullable.js b/jscomp/test/test_zero_nullable.js
index a6a2b9c435..49ae58e7d4 100644
--- a/jscomp/test/test_zero_nullable.js
+++ b/jscomp/test/test_zero_nullable.js
@@ -8,7 +8,7 @@ function f1(x) {
     return 3;
   }
   else {
-    return x + 1;
+    return x + 1 | 0;
   }
 }
 
@@ -17,7 +17,7 @@ function f2(x) {
     return 3;
   }
   else {
-    return x + 1;
+    return x + 1 | 0;
   }
 }
 
@@ -27,18 +27,18 @@ function f5(h, _) {
     return 3;
   }
   else {
-    return u + 1;
+    return u + 1 | 0;
   }
 }
 
 function f4(h, x) {
   var u = Caml_curry.app1(h, 32);
-  var v = 32 + x;
+  var v = 32 + x | 0;
   if (u === null) {
-    return 1 + v;
+    return 1 + v | 0;
   }
   else {
-    return u + 1;
+    return u + 1 | 0;
   }
 }
 
@@ -84,7 +84,7 @@ function f1$1(x) {
     return 3;
   }
   else {
-    return x + 1;
+    return x + 1 | 0;
   }
 }
 
@@ -93,7 +93,7 @@ function f2$1(x) {
     return 3;
   }
   else {
-    return x + 1;
+    return x + 1 | 0;
   }
 }
 
@@ -103,18 +103,18 @@ function f5$1(h, _) {
     return 3;
   }
   else {
-    return u + 1;
+    return u + 1 | 0;
   }
 }
 
 function f4$1(h, x) {
   var u = Caml_curry.app1(h, 32);
-  var v = 32 + x;
+  var v = 32 + x | 0;
   if (u === undefined) {
-    return 1 + v;
+    return 1 + v | 0;
   }
   else {
-    return u + 1;
+    return u + 1 | 0;
   }
 }
 
diff --git a/jscomp/test/ticker.js b/jscomp/test/ticker.js
index 807b98d64c..bfbaae862a 100644
--- a/jscomp/test/ticker.js
+++ b/jscomp/test/ticker.js
@@ -37,7 +37,7 @@ function split(delim, s) {
           }
         }
         if (exit === 1) {
-          var l_000 = $$String.sub(s, i$prime + 1, i - i$prime - 1);
+          var l_000 = $$String.sub(s, i$prime + 1 | 0, i - i$prime - 1);
           var l$1 = /* :: */[
             l_000,
             l
@@ -156,7 +156,7 @@ function create(l, x, d, r) {
           1: x,
           2: d,
           3: r,
-          4: hl >= hr ? hl + 1 : hr + 1,
+          4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
           length: 5,
           tag: 0
         };
@@ -177,7 +177,7 @@ function singleton(x, d) {
 function bal(l, x, d, r) {
   var hl = l ? l[4] : 0;
   var hr = r ? r[4] : 0;
-  if (hl > hr + 2) {
+  if (hl > (hr + 2 | 0)) {
     if (l) {
       var lr = l[3];
       var ld = l[2];
@@ -203,7 +203,7 @@ function bal(l, x, d, r) {
           ];
     }
   }
-  else if (hr > hl + 2) {
+  else if (hr > (hl + 2 | 0)) {
     if (r) {
       var rr = r[3];
       var rd = r[2];
@@ -235,7 +235,7 @@ function bal(l, x, d, r) {
             1: x,
             2: d,
             3: r,
-            4: hl >= hr ? hl + 1 : hr + 1,
+            4: hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
             length: 5,
             tag: 0
           };
@@ -574,10 +574,10 @@ function join(l, v, d, r) {
     if (r) {
       var rh = r[4];
       var lh = l[4];
-      if (lh > rh + 2) {
+      if (lh > (rh + 2 | 0)) {
         return bal(l[0], l[1], l[2], join(l[3], v, d, r));
       }
-      else if (rh > lh + 2) {
+      else if (rh > (lh + 2 | 0)) {
         return bal(join(l, v, d, r[0]), r[1], r[2], r[3]);
       }
       else {
@@ -845,7 +845,7 @@ function equal(cmp, m1, m2) {
 
 function cardinal(param) {
   if (param) {
-    return cardinal(param[0]) + 1 + cardinal(param[3]);
+    return (cardinal(param[0]) + 1 | 0) + cardinal(param[3]) | 0;
   }
   else {
     return 0;
@@ -920,7 +920,7 @@ function compute_update_sequences(all_tickers) {
                 var match$1 = match[0];
                 var counter$1 = loop(counter, match$1[/* lhs */2]);
                 var counter$2 = loop(counter$1, match$1[/* rhs */1]);
-                var counter$3 = counter$2 + 1;
+                var counter$3 = counter$2 + 1 | 0;
                 ticker[/* rank */1] = /* Ranked */{
                   0: counter$3,
                   length: 1,
@@ -929,7 +929,7 @@ function compute_update_sequences(all_tickers) {
                 return counter$3;
               }
               else {
-                var counter$4 = counter + 1;
+                var counter$4 = counter + 1 | 0;
                 ticker[/* rank */1] = /* Ranked */{
                   0: counter$4,
                   length: 1,