diff --git a/CHANGELOG.md b/CHANGELOG.md
index e6d250c84c..128fcf744d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -39,6 +39,7 @@
 
 #### :house: Internal
 
+- Remove dead compiler code: warning 24, the `J.String_index` JS IR node, the `Pisint` and `Parraysets` Lambda primitives with their unused `%` primitive names (`%obj_is_int`, `%obj_dup`, `%obj_field`, `%array_safe_set`, `%null_to_opt`, `%nullable_to_opt`), the no-op `-pp` bsc flag and unread `Clflags` fields (`-unsafe` stays accepted as an explicit no-op), and the unused `unit` slot of `Pexp_coerce`. https://github.com/rescript-lang/rescript/pull/8731
 - Represent inline record definitions with an explicit parsetree origin while retaining the existing PPX wire representation. https://github.com/rescript-lang/rescript/pull/8686
 - Make expression attributes immutable in the current parsetree, now that editor refactors construct new expression nodes. https://github.com/rescript-lang/rescript/pull/8685
 - Remove the unused `pat_record_label` alias from the current parsetree. https://github.com/rescript-lang/rescript/pull/8684
diff --git a/compiler/bsc/rescript_compiler_main.ml b/compiler/bsc/rescript_compiler_main.ml
index b3d51c1e98..949d42f6c5 100644
--- a/compiler/bsc/rescript_compiler_main.ml
+++ b/compiler/bsc/rescript_compiler_main.ml
@@ -437,7 +437,6 @@ let command_line_flags : (string * Bsc_args.spec * string) array =
     ("-only-parse", set Clflags.only_parse, "*internal* stop after parsing");
     ( "-editor-mode",
       unit_call (fun () ->
-          Clflags.editor_mode := true;
           Clflags.ignore_parse_errors := true;
           Js_config.cmi_only := true),
       "*internal* Enable editor mode." );
@@ -458,9 +457,6 @@ let command_line_flags : (string * Bsc_args.spec * string) array =
       unit_call print_version_string,
       "Print compiler version and location of standard library and exit" );
     ("-version", unit_call print_version_string, "Print version and exit");
-    ( "-pp",
-      string_optional_set Clflags.preprocessor,
-      "*internal* <command>  Pipe sources through preprocessor <command>" );
     ( "-absname",
       set absname,
       "*internal* Show absolute filenames in error messages" );
@@ -475,9 +471,7 @@ let command_line_flags : (string * Bsc_args.spec * string) array =
     ( "-short-paths",
       clear Clflags.real_paths,
       "*internal* Shorten paths in types" );
-    ( "-unsafe",
-      set Clflags.fast,
-      "*internal* Do not compile bounds checking on array and string access" );
+    ("-unsafe", Unit_dummy, "*internal* No longer used and is a no-op.");
     ( "-runtime-path",
       string_call setup_runtime_path,
       "*internal* Set the path of the runtime package (@rescript/runtime)" );
diff --git a/compiler/core/j.ml b/compiler/core/j.ml
index bae9a7886a..1424757f02 100644
--- a/compiler/core/j.ml
+++ b/compiler/core/j.ml
@@ -99,8 +99,6 @@ and expression_desc =
       some primitive  call is translated
       into a plain call, it's better to keep them
   *)
-  | String_index of expression * expression
-  (* str.[i])*)
   | Array_index of expression * expression
   (* arr.(i)
      Invariant:
diff --git a/compiler/core/js_analyzer.ml b/compiler/core/js_analyzer.ml
index a920b1750c..9b084de23d 100644
--- a/compiler/core/js_analyzer.ml
+++ b/compiler/core/js_analyzer.ml
@@ -110,8 +110,7 @@ let rec no_side_effect_expression_desc (x : J.expression_desc) =
   | Json_literal _ -> true
   | Static_index (obj, (_name : string), (_pos : int32 option)) ->
     no_side_effect obj
-  | String_index (a, b) | Array_index (a, b) ->
-    no_side_effect a && no_side_effect b
+  | Array_index (a, b) -> no_side_effect a && no_side_effect b
   | Is_null_or_undefined b -> no_side_effect b
   | Str _ | Template_literal _ -> true
   | Interpolated_template {values} -> Ext_list.for_all values no_side_effect
@@ -217,10 +216,6 @@ let rec eq_expression ({expression_desc = x0} : J.expression)
       false (* conservative *)
      | _ -> false
      end *)
-  | String_index (a0, a1) -> (
-    match y0 with
-    | String_index (b0, b1) -> eq_expression a0 b0 && eq_expression a1 b1
-    | _ -> false)
   | Array_index (a0, a1) -> (
     match y0 with
     | Array_index (b0, b1) -> eq_expression a0 b0 && eq_expression a1 b1
diff --git a/compiler/core/js_dump.ml b/compiler/core/js_dump.ml
index a23255c8c2..46889b6cb5 100644
--- a/compiler/core/js_dump.ml
+++ b/compiler/core/js_dump.ml
@@ -142,10 +142,9 @@ let rec exp_need_paren ?(arrow = false) (e : J.expression) =
   | Json_literal _ -> true
   | Raw_js_code {code_info = Stmt _}
   | Length _ | Call _ | Caml_block_tag _ | Seq _ | Static_index _ | Cond _
-  | Bin _ | Is_null_or_undefined _ | String_index _ | Array_index _
-  | String_append _ | Var _ | Undefined _ | Null | Str _ | Template_literal _
-  | Array _ | Caml_block _ | Typeof _ | Number _ | Js_not _ | Js_bnot _ | In _
-  | Bool _ | New _ ->
+  | Bin _ | Is_null_or_undefined _ | Array_index _ | String_append _ | Var _
+  | Undefined _ | Null | Str _ | Template_literal _ | Array _ | Caml_block _
+  | Typeof _ | Number _ | Js_not _ | Js_bnot _ | In _ | Bool _ | New _ ->
     false
   | Await _ -> false
   | Spread _ -> false
@@ -715,13 +714,6 @@ and expression_desc cxt ~(level : int) f x : cxt =
     let cxt = print_segments cxt segments values in
     P.string f "`";
     cxt
-  | String_index (a, b) ->
-    P.group f 1 (fun _ ->
-        let cxt = expression ~level:15 cxt f a in
-        P.string f L.dot;
-        P.string f L.code_point_at;
-        (* FIXME: use code_point_at *)
-        P.paren_group f 1 (fun _ -> expression ~level:0 cxt f b))
   | Str txt ->
     Js_dump_string.pp_string f txt;
     cxt
diff --git a/compiler/core/js_dump_lit.ml b/compiler/core/js_dump_lit.ml
index b43b2d4591..52869920cc 100644
--- a/compiler/core/js_dump_lit.ml
+++ b/compiler/core/js_dump_lit.ml
@@ -70,8 +70,6 @@ let default = "default"
 
 let length = "length"
 
-let code_point_at = "codePointAt"
-
 let new_ = "new"
 
 let question = "?"
diff --git a/compiler/core/js_exp_make.ml b/compiler/core/js_exp_make.ml
index 2e15b1a20f..5ddd6ce935 100644
--- a/compiler/core/js_exp_make.ml
+++ b/compiler/core/js_exp_make.ml
@@ -1491,9 +1491,6 @@ let string_comp (cmp : Lambda.comparison) ?comment (e0 : t) (e1 : t) =
 
 let string_equal ?comment (e0 : t) (e1 : t) : t = string_comp Ceq ?comment e0 e1
 
-let is_type_number ?comment (e : t) : t =
-  string_equal ?comment (typeof e) (str "number")
-
 let is_type_object (e : t) : t = string_equal (typeof e) (str "object")
 
 let obj_length ?comment e : t =
diff --git a/compiler/core/js_exp_make.mli b/compiler/core/js_exp_make.mli
index 9f2e6681a6..a534a21200 100644
--- a/compiler/core/js_exp_make.mli
+++ b/compiler/core/js_exp_make.mli
@@ -179,8 +179,6 @@ val eq_null_undefined_boolean : ?comment:string -> t -> t -> t
 
 val neq_null_undefined_boolean : ?comment:string -> t -> t -> t
 
-val is_type_number : ?comment:string -> t -> t
-
 val is_int_tag : ?has_null_undefined_other:bool * bool * bool -> t -> t
 
 val is_a_literal_case :
diff --git a/compiler/core/js_record_fold.ml b/compiler/core/js_record_fold.ml
index dd98db728a..e4b79a519e 100644
--- a/compiler/core/js_record_fold.ml
+++ b/compiler/core/js_record_fold.ml
@@ -130,10 +130,6 @@ let expression_desc : 'a. ('a, expression_desc) fn =
     let st = list _self.expression _self st _x2 in
     st
   | Interpolated_template {values} -> list _self.expression _self st values
-  | String_index (_x0, _x1) ->
-    let st = _self.expression _self st _x0 in
-    let st = _self.expression _self st _x1 in
-    st
   | Array_index (_x0, _x1) ->
     let st = _self.expression _self st _x0 in
     let st = _self.expression _self st _x1 in
diff --git a/compiler/core/js_record_iter.ml b/compiler/core/js_record_iter.ml
index d532ad3f96..6f6e89cfec 100644
--- a/compiler/core/js_record_iter.ml
+++ b/compiler/core/js_record_iter.ml
@@ -105,9 +105,6 @@ let expression_desc : expression_desc fn =
     _self.expression _self _x0;
     list _self.expression _self _x2
   | Interpolated_template {values} -> list _self.expression _self values
-  | String_index (_x0, _x1) ->
-    _self.expression _self _x0;
-    _self.expression _self _x1
   | Array_index (_x0, _x1) ->
     _self.expression _self _x0;
     _self.expression _self _x1
diff --git a/compiler/core/js_record_map.ml b/compiler/core/js_record_map.ml
index 198d4b39d5..68ba6f5e5b 100644
--- a/compiler/core/js_record_map.ml
+++ b/compiler/core/js_record_map.ml
@@ -134,10 +134,6 @@ let expression_desc : expression_desc fn =
   | Interpolated_template ({values} as template) ->
     let values = list _self.expression _self values in
     Interpolated_template {template with values}
-  | String_index (_x0, _x1) ->
-    let _x0 = _self.expression _self _x0 in
-    let _x1 = _self.expression _self _x1 in
-    String_index (_x0, _x1)
   | Array_index (_x0, _x1) ->
     let _x0 = _self.expression _self _x0 in
     let _x1 = _self.expression _self _x1 in
diff --git a/compiler/core/lam_analysis.ml b/compiler/core/lam_analysis.ml
index a53290427f..1b90637c48 100644
--- a/compiler/core/lam_analysis.ml
+++ b/compiler/core/lam_analysis.ml
@@ -85,7 +85,7 @@ let rec no_side_effects (lam : Lambda.t) : bool =
     (* dict primitives *)
     | Pmakedict | Pdict_has
     (* Test if the argument is a block or an immediate integer *)
-    | Pisint | Pis_poly_var_block
+    | Pis_poly_var_block
     (* Test if the (integer) argument is outside an interval *)
     (* Operations on big arrays: (unsafe, #dimensions, kind, layout) *)
     (* Compile time constants *)
@@ -104,7 +104,7 @@ let rec no_side_effects (lam : Lambda.t) : bool =
     (* TODO *)
     | Praw_js_code _
     (* byte swap *)
-    | Parraysets | Parraysetu | Praise | Psetfield _
+    | Parraysetu | Praise | Psetfield _
     (* bounds-checked reads throw when the index is out of range *)
     | Parrayrefs | Pstringrefs | Pstringrefu ->
       false)
diff --git a/compiler/core/lam_compile_primitive.ml b/compiler/core/lam_compile_primitive.ml
index a6f3c4eb49..c1d859b02d 100644
--- a/compiler/core/lam_compile_primitive.ml
+++ b/compiler/core/lam_compile_primitive.ml
@@ -558,7 +558,6 @@ let translate output_prefix loc (cxt : Lam_compile_context.t)
     | [e; e1] -> Js_of_lam_array.ref_array e e1 (* Todo: Constant Folding *)
     | _ -> assert false)
   | Parrayrefs -> E.runtime_call Primitive_modules.array "get" args
-  | Parraysets -> E.runtime_call Primitive_modules.array "set" args
   | Pmakearray -> Js_of_lam_array.make_array args
   | Pmakelist ->
     Js_of_lam_block.make_block
@@ -604,7 +603,6 @@ let translate output_prefix loc (cxt : Lam_compile_context.t)
     Lam_compile_external_call.translate_ffi cxt arg_types ~prim_name ffi args
       ~transformed_jsx
   (* FIXME, this can be removed later *)
-  | Pisint -> E.is_type_number (Ext_list.singleton_exn args)
   | Pis_poly_var_block -> E.is_type_object (Ext_list.singleton_exn args)
   | Pduprecord -> (
     match args with
diff --git a/compiler/ext/warnings.ml b/compiler/ext/warnings.ml
index 9e09285b5b..0dfa7fe440 100644
--- a/compiler/ext/warnings.ml
+++ b/compiler/ext/warnings.ml
@@ -40,7 +40,6 @@ type t =
   | Nonreturning_statement (* 21 *)
   | Preprocessor of string (* 22 *)
   | Useless_record_with (* 23 *)
-  | Bad_module_name of string (* 24 *)
   | All_clauses_guarded (* 8, used to be 25 *)
   | Unused_var of string (* 26 *)
   | Unused_var_strict of string (* 27 *)
@@ -95,7 +94,6 @@ let number = function
   | Nonreturning_statement -> 21
   | Preprocessor _ -> 22
   | Useless_record_with -> 23
-  | Bad_module_name _ -> 24
   | All_clauses_guarded -> 8 (* used to be 25 *)
   | Unused_var _ -> 26
   | Unused_var_strict _ -> 27
@@ -299,12 +297,6 @@ let message = function
   | Useless_record_with ->
     "All the fields are already explicitly listed in this record. You can \
      remove the `...` spread."
-  | Bad_module_name modname ->
-    "This file's name is potentially invalid. The build systems conventionally \
-     turn a file name into a module name by upper-casing the first letter. "
-    ^ modname ^ " isn't a valid module name.\n"
-    ^ "Note: some build systems might e.g. turn kebab-case into CamelCase \
-       module, which is why this isn't a hard error."
   | All_clauses_guarded ->
     "this pattern-matching is not exhaustive.\n\
      All clauses in this pattern-matching are guarded."
@@ -523,9 +515,6 @@ let descriptions =
     (21, "Non-returning statement.");
     (22, "Preprocessor warning.");
     (23, "Useless record \"with\" clause.");
-    ( 24,
-      "Bad module name: the source file name is not a valid ReScript module \
-       name." );
     (25, "Deprecated: now part of warning 8.");
     ( 26,
       "Suspicious unused variable: unused variable that is bound\n\
diff --git a/compiler/ext/warnings.mli b/compiler/ext/warnings.mli
index 0d71b855b5..3e5529b66c 100644
--- a/compiler/ext/warnings.mli
+++ b/compiler/ext/warnings.mli
@@ -33,7 +33,6 @@ type t =
   | Nonreturning_statement (* 21 *)
   | Preprocessor of string (* 22 *)
   | Useless_record_with (* 23 *)
-  | Bad_module_name of string (* 24 *)
   | All_clauses_guarded (* 8, used to be 25 *)
   | Unused_var of string (* 26 *)
   | Unused_var_strict of string (* 27 *)
diff --git a/compiler/ml/ast_helper.ml b/compiler/ml/ast_helper.ml
index 5aebf79cf2..e6f6d82dea 100644
--- a/compiler/ml/ast_helper.ml
+++ b/compiler/ml/ast_helper.ml
@@ -187,7 +187,7 @@ module Exp = struct
   let for_await_of ?loc ?attrs a b c =
     mk ?loc ?attrs (Pexp_for_await_of (a, b, c))
   let constraint_ ?loc ?attrs a b = mk ?loc ?attrs (Pexp_constraint (a, b))
-  let coerce ?loc ?attrs a c = mk ?loc ?attrs (Pexp_coerce (a, (), c))
+  let coerce ?loc ?attrs a c = mk ?loc ?attrs (Pexp_coerce (a, c))
   let object_get ?loc ?attrs a b = mk ?loc ?attrs (Pexp_object_get (a, b))
   let object_set ?loc ?attrs a b c = mk ?loc ?attrs (Pexp_object_set (a, b, c))
   let object_literal ?loc ?attrs a = mk ?loc ?attrs (Pexp_object_literal a)
diff --git a/compiler/ml/ast_iterator.ml b/compiler/ml/ast_iterator.ml
index f05bab284d..301d38efe5 100644
--- a/compiler/ml/ast_iterator.ml
+++ b/compiler/ml/ast_iterator.ml
@@ -368,7 +368,7 @@ module E = struct
       sub.pat sub p;
       sub.expr sub e1;
       sub.expr sub e2
-    | Pexp_coerce (e, (), t2) ->
+    | Pexp_coerce (e, t2) ->
       sub.expr sub e;
       sub.typ sub t2
     | Pexp_constraint (e, t) ->
diff --git a/compiler/ml/ast_mapper.ml b/compiler/ml/ast_mapper.ml
index a8b4da96b8..52117a481b 100644
--- a/compiler/ml/ast_mapper.ml
+++ b/compiler/ml/ast_mapper.ml
@@ -369,7 +369,7 @@ module E = struct
       Exp.tagged_template ~loc ~attrs (sub.expr sub tag)
         (List.map (map_loc sub) raw_sources)
         (List.map (sub.expr sub) values)
-    | Pexp_coerce (e, (), t2) ->
+    | Pexp_coerce (e, t2) ->
       coerce ~loc ~attrs (sub.expr sub e) (sub.typ sub t2)
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
diff --git a/compiler/ml/ast_mapper_to0.ml b/compiler/ml/ast_mapper_to0.ml
index c1bf3b8855..980c358755 100644
--- a/compiler/ml/ast_mapper_to0.ml
+++ b/compiler/ml/ast_mapper_to0.ml
@@ -721,7 +721,7 @@ module E = struct
           ( Asttypes.Noloc.Nolabel,
             Ast_helper0.Exp.array ~loc (List.map (sub.expr sub) values) );
         ]
-    | Pexp_coerce (e, (), t2) ->
+    | Pexp_coerce (e, t2) ->
       coerce ~loc ~attrs (sub.expr sub e) (sub.typ sub t2)
     | Pexp_constraint (e, t) ->
       constraint_ ~loc ~attrs (sub.expr sub e) (sub.typ sub t)
diff --git a/compiler/ml/clflags.ml b/compiler/ml/clflags.ml
index f4db4c370f..a21c3626b8 100644
--- a/compiler/ml/clflags.ml
+++ b/compiler/ml/clflags.ml
@@ -4,12 +4,8 @@ and include_dirs = ref ([] : string list) (* -I *)
 
 and debug = ref false (* -g *)
 
-and fast = ref false (* -unsafe *)
-
 and nopervasives = ref false (* -nopervasives *)
 
-and preprocessor = ref (None : string option) (* -pp *)
-
 and all_ppx = ref ([] : string list)
 
 (* -ppx *)
@@ -23,8 +19,6 @@ and open_modules = ref [] (* -open *)
 
 and real_paths = ref true (* -short-paths *)
 
-and applicative_functors = ref true (* -no-app-funct *)
-
 and error_size = ref 400 (* -error-size, in heap words *)
 
 and transparent_modules = ref false (* -trans-mod *)
@@ -39,8 +33,6 @@ and dump_coercions = ref false (* -draw-coercions *)
 
 and only_parse = ref false (* -only-parse *)
 
-and editor_mode = ref false (* -editor-mode *)
-
 and ignore_parse_errors = ref false (* -ignore-parse-errors *)
 
 let dont_write_files = ref false (* set to true under ocamldoc *)
diff --git a/compiler/ml/clflags.mli b/compiler/ml/clflags.mli
index 79ecb6ecff..587857714f 100644
--- a/compiler/ml/clflags.mli
+++ b/compiler/ml/clflags.mli
@@ -2,17 +2,14 @@ val output_name : string option ref
 val include_dirs : string list ref
 
 val debug : bool ref
-val fast : bool ref
 
 val nopervasives : bool ref
 val open_modules : string list ref
-val preprocessor : string option ref
 val all_ppx : string list ref
 val binary_annotations : bool ref
 val noassert : bool ref
 val verbose : bool ref
 val real_paths : bool ref
-val applicative_functors : bool ref
 val error_size : int ref
 val transparent_modules : bool ref
 val dump_source : bool ref
@@ -24,7 +21,6 @@ val dont_write_files : bool ref
 val keep_locs : bool ref
 val only_parse : bool ref
 val ignore_parse_errors : bool ref
-val editor_mode : bool ref
 
 val parse_color_setting : string -> Misc.Color.setting option
 val color : Misc.Color.setting option ref
diff --git a/compiler/ml/depend.ml b/compiler/ml/depend.ml
index 50a4b5aee2..e18d5040cc 100644
--- a/compiler/ml/depend.ml
+++ b/compiler/ml/depend.ml
@@ -277,7 +277,7 @@ let rec add_expr bv exp =
     add_pattern bv pat |> ignore;
     add_expr bv e1;
     add_expr bv e2
-  | Pexp_coerce (e1, (), ty3) ->
+  | Pexp_coerce (e1, ty3) ->
     add_expr bv e1;
     add_type bv ty3
   | Pexp_constraint (e1, ty2) ->
diff --git a/compiler/ml/lambda.ml b/compiler/ml/lambda.ml
index 7988f06da6..20f8202156 100644
--- a/compiler/ml/lambda.ml
+++ b/compiler/ml/lambda.ml
@@ -227,7 +227,6 @@ type primitive =
   | Parrayrefu
   | Parraysetu
   | Parrayrefs
-  | Parraysets
   (* List primitives *)
   | Pmakelist
   (* dict primitives *)
@@ -245,7 +244,6 @@ type primitive =
   | Phash_mixstring
   | Phash_finalmix
   (* Test if the argument is a block or an immediate integer *)
-  | Pisint
   (* Test if the (integer) argument is outside an interval *)
   (* Test if the argument is null or undefined *)
   | Pis_null_undefined
@@ -464,7 +462,7 @@ let eq_primitive_approx (lhs : primitive) (rhs : primitive) =
   (* bool primitives *)
   | Psequand | Psequor | Pnot | Pboolcomp _ | Pboolorder | Pboolmin | Pboolmax
   (* int primitives *)
-  | Pisint | Pnegint | Paddint | Psubint | Pmulint | Pdivint | Pmodint | Ppowint
+  | Pnegint | Paddint | Psubint | Pmulint | Pdivint | Pmodint | Ppowint
   | Pnotint | Pandint | Porint | Pxorint | Plslint | Plsrint | Pasrint
   | Pintorder | Pintmin | Pintmax
   (* float primitives *)
@@ -488,7 +486,7 @@ let eq_primitive_approx (lhs : primitive) (rhs : primitive) =
   | Pnull_undefined_to_opt | Pis_null | Pis_not_none | Psome | Psome_not_nest
   | Pis_undefined | Pis_null_undefined | Ptypeof | Pis_poly_var_block
   | Pdebugger | Pinit_mod | Pupdate_mod | Pduprecord | Pmakearray | Parraylength
-  | Parrayrefu | Parraysetu | Parrayrefs | Parraysets | Pjs_fn_method | Phash
+  | Parrayrefu | Parraysetu | Parrayrefs | Pjs_fn_method | Phash
   | Phash_mixstring | Phash_mixint | Phash_finalmix | Precord_rest _ ->
     rhs = lhs
   (* Reachable only via the optimizer's term-equality comparison, which the
@@ -1194,44 +1192,7 @@ let if_ (a : t) (b : t) (c : t) : t =
        matching's own exit bookkeeping inspects after the term is assembled,
        and doing it here leaves static raises without their catch. It is
        {!Lam_pass_guard_raises} instead. *)
-    | _ -> (
-      match a with
-      | Lprim {primitive = Pisint; args = [Lvar i]; _} -> (
-        match b with
-        | Lifthenelse
-            (Lprim {primitive = Pintcomp Ceq; args = [Lvar j; Lconst _]}, _, b_f)
-          when Ident.same i j && eq_approx b_f c ->
-          b
-        | Lprim {primitive = Pintcomp Ceq; args = [Lvar j; Lconst _]}
-          when Ident.same i j && eq_approx lambda_false c ->
-          b
-        | Lifthenelse
-            ( Lprim
-                ({primitive = Pintcomp Cneq; args = [Lvar j; Lconst _]} as
-                 b_pred),
-              b_t,
-              b_f )
-          when Ident.same i j && eq_approx b_t c ->
-          Lifthenelse (Lprim {b_pred with primitive = Pintcomp Ceq}, b_f, b_t)
-        | Lprim
-            {primitive = Pintcomp Cneq; args = [Lvar j; Lconst _] as args; loc}
-        | Lprim
-            {
-              primitive = Pnot;
-              args =
-                [
-                  Lprim
-                    {
-                      primitive = Pintcomp Ceq;
-                      args = [Lvar j; Lconst _] as args;
-                      loc;
-                    };
-                ];
-            }
-          when Ident.same i j && eq_approx lambda_true c ->
-          Lprim {primitive = Pintcomp Cneq; args; loc}
-        | _ -> Lifthenelse (a, b, c))
-      | _ -> Lifthenelse (a, b, c)))
+    | _ -> Lifthenelse (a, b, c))
 
 let sequor l r = if_ l lambda_true r
 
diff --git a/compiler/ml/lambda.mli b/compiler/ml/lambda.mli
index 03b9ecdafe..e39c9bb11c 100644
--- a/compiler/ml/lambda.mli
+++ b/compiler/ml/lambda.mli
@@ -228,7 +228,6 @@ type primitive =
   | Parrayrefu
   | Parraysetu
   | Parrayrefs
-  | Parraysets
   (* List primitives *)
   | Pmakelist
   (* dict primitives *)
@@ -245,8 +244,6 @@ type primitive =
   | Phash_mixint
   | Phash_mixstring
   | Phash_finalmix
-  (* Test if the argument is a block or an immediate integer *)
-  | Pisint
   (* Test if the (integer) argument is outside an interval *)
   (* Test if the argument is null or undefined *)
   | Pis_null_undefined
@@ -444,8 +441,7 @@ val const_is_allocating : structured_constant -> bool
      collapses a module record rebuilt field-by-field from another module
      back to that module.
    - [if_] resolves a constant condition, collapses a branch that asserts
-     false, turns boolean branches into the condition or its negation, and
-     recognizes a few [Pisint] shapes.
+     false, turns boolean branches into the condition or its negation.
    - [switch] and [stringswitch] pick the matching case when the scrutinee
      is constant.
    - [not_] rewrites a negated inequality into an equality.
diff --git a/compiler/ml/mtype.ml b/compiler/ml/mtype.ml
index 8fb04fdc84..dddeb68223 100644
--- a/compiler/ml/mtype.ml
+++ b/compiler/ml/mtype.ml
@@ -30,8 +30,7 @@ let freshen mty = Subst.modtype Subst.identity mty
 let rec strengthen ~aliasable env mty p =
   match scrape env mty with
   | Mty_signature sg -> Mty_signature (strengthen_sig ~aliasable env sg p 0)
-  | Mty_functor (param, arg, res)
-    when !Clflags.applicative_functors && Ident.name param <> "*" ->
+  | Mty_functor (param, arg, res) when Ident.name param <> "*" ->
     Mty_functor
       ( param,
         arg,
diff --git a/compiler/ml/parsetree.ml b/compiler/ml/parsetree.ml
index ece42423b0..752ad78fe0 100644
--- a/compiler/ml/parsetree.ml
+++ b/compiler/ml/parsetree.ml
@@ -356,9 +356,7 @@ and expression_desc =
        for i = E1 downto E2 do E3 done  (flag = Downto)
     *)
   | Pexp_constraint of expression * core_type (* (E : T) *)
-  | Pexp_coerce of expression * unit * core_type
-    (* (E :> T)        (None, T)
-         *)
+  | Pexp_coerce of expression * core_type (* (E :> T) *)
   | Pexp_object_get of expression * label loc (* obj["x"] *)
   | Pexp_object_set of expression * label loc * expression (* obj["x"] = v *)
   | Pexp_object_literal of (label loc * expression) list
diff --git a/compiler/ml/pprintast.ml b/compiler/ml/pprintast.ml
index 358bd50a88..626797d3f9 100644
--- a/compiler/ml/pprintast.ml
+++ b/compiler/ml/pprintast.ml
@@ -841,7 +841,7 @@ and simple_expr ctxt f x =
       pp f "@[<hov2>(%a)@]" (list (simple_expr ctxt) ~sep:",@;") l
     | Pexp_constraint (e, ct) ->
       pp f "(%a :@ %a)" (expression ctxt) e (core_type ctxt) ct
-    | Pexp_coerce (e, (), ct) ->
+    | Pexp_coerce (e, ct) ->
       pp f "(%a :> %a)" (expression ctxt) e (core_type ctxt) ct
     | Pexp_variant (l, {txt = []}) -> pp f "`%s" l
     | Pexp_record (l, eo) ->
diff --git a/compiler/ml/printast.ml b/compiler/ml/printast.ml
index 549ede858b..c4767e7b3d 100644
--- a/compiler/ml/printast.ml
+++ b/compiler/ml/printast.ml
@@ -357,7 +357,7 @@ and expression i ppf x =
     line i ppf "Pexp_constraint\n";
     expression i ppf e;
     core_type i ppf ct
-  | Pexp_coerce (e, (), cto2) ->
+  | Pexp_coerce (e, cto2) ->
     line i ppf "Pexp_coerce\n";
     expression i ppf e;
     core_type i ppf cto2
diff --git a/compiler/ml/printlambda.ml b/compiler/ml/printlambda.ml
index 95499f5c20..123bc4c1b9 100644
--- a/compiler/ml/printlambda.ml
+++ b/compiler/ml/printlambda.ml
@@ -192,11 +192,9 @@ let primitive ppf = function
   | Parrayrefu -> fprintf ppf "array.unsafe_get"
   | Parraysetu -> fprintf ppf "array.unsafe_set"
   | Parrayrefs -> fprintf ppf "array.get"
-  | Parraysets -> fprintf ppf "array.set"
   | Pmakelist -> fprintf ppf "makelist"
   | Pmakedict -> fprintf ppf "makedict"
   | Pdict_has -> fprintf ppf "dict.has"
-  | Pisint -> fprintf ppf "isint"
   | Pis_null -> fprintf ppf "is_null"
   | Pis_undefined -> fprintf ppf "is_undefined"
   | Pis_null_undefined -> fprintf ppf "isnullable"
diff --git a/compiler/ml/translcore.ml b/compiler/ml/translcore.ml
index ac0c4bac27..0079a7e351 100644
--- a/compiler/ml/translcore.ml
+++ b/compiler/ml/translcore.ml
@@ -269,7 +269,6 @@ let primitive_builtins : (string * Lambda.builtin) array =
       (* Finish Triples for  ref data type *)
       ("%field0", Pfield (0, Fld_tuple));
       ("%field1", Pfield (1, Fld_tuple));
-      ("%obj_dup", Pduprecord);
       ("%obj_tag", Pobjtag);
       ("%obj_size", Pobjsize);
       ("%obj_get_field", Parrayrefu);
@@ -283,7 +282,6 @@ let primitive_builtins : (string * Lambda.builtin) array =
       ("%boolmin", Pboolmin);
       ("%boolmax", Pboolmax);
       (* int primitives *)
-      ("%obj_is_int", Pisint);
       ("%negint", Pnegint);
       ("%addint", Paddint);
       ("%subint", Psubint);
@@ -356,7 +354,6 @@ let primitive_builtins : (string * Lambda.builtin) array =
       (* array primitives *)
       ("%array_length", Parraylength);
       ("%array_safe_get", Parrayrefs);
-      ("%array_safe_set", Parraysets);
       ("%array_unsafe_get", Parrayrefu);
       ("%array_unsafe_set", Parraysetu);
       (* dict primitives *)
@@ -382,8 +379,6 @@ let primitive_builtins : (string * Lambda.builtin) array =
       ("%unsafe_gt", Pjscomp Cgt);
       ("%unsafe_ge", Pjscomp Cge);
       ("%is_nullable", Pis_null_undefined);
-      ("%null_to_opt", Pnull_to_opt);
-      ("%nullable_to_opt", Pnull_undefined_to_opt);
       ("%makemutablelist", Pmakelist);
       ("%unsafe_to_method", Pjs_fn_method);
       (* Compiler internals, never expose to ReScript files *)
@@ -393,8 +388,6 @@ let primitive_builtins : (string * Lambda.builtin) array =
       ("#null_to_opt", Pnull_to_opt);
       ("#nullable_to_opt", Pnull_undefined_to_opt);
       ("#makemutablelist", Pmakelist);
-      (* FIXME: Deprecated *)
-      ("%obj_field", Parrayrefu);
     |]
 
 let builtins_table : (string, Lambda.builtin) Hashtbl.t =
diff --git a/compiler/ml/typecore.ml b/compiler/ml/typecore.ml
index 234803b3a6..9f4f96a845 100644
--- a/compiler/ml/typecore.ml
+++ b/compiler/ml/typecore.ml
@@ -195,7 +195,7 @@ let iter_expression f e =
     | Pexp_open (_, _, e)
     | Pexp_assert e
     | Pexp_constraint (e, _)
-    | Pexp_coerce (e, _, _)
+    | Pexp_coerce (e, _)
     | Pexp_letexception (_, e)
     | Pexp_object_get (e, _)
     | Pexp_field (e, _) ->
@@ -2057,7 +2057,7 @@ let rec type_approx env sexp =
        raise
          (Error (sexp.pexp_loc, env, Expr_type_clash {trace; context = None})));
     ty1
-  | Pexp_coerce (e, (), sty2) ->
+  | Pexp_coerce (e, sty2) ->
     let approx_ty_opt = function
       | None -> newvar ()
       | Some sty -> approx_type env sty
@@ -3294,7 +3294,7 @@ and type_expect_ ?deprecated_context ~context ?(recarg = Rejected) env sexp
         exp_extra =
           (Texp_constraint cty, loc, sexp.pexp_attributes) :: arg.exp_extra;
       }
-  | Pexp_coerce (sarg, (), sty') ->
+  | Pexp_coerce (sarg, sty') ->
     let separate = true in
     (* always separate, 1% slowdown for lablgtk *)
     (* Also see PR#7199 for a problem with the following:
diff --git a/compiler/ml/typemod.ml b/compiler/ml/typemod.ml
index e8fae41c9b..b472ea5262 100644
--- a/compiler/ml/typemod.ml
+++ b/compiler/ml/typemod.ml
@@ -982,7 +982,7 @@ exception Not_a_path
 let rec path_of_module mexp =
   match mexp.mod_desc with
   | Tmod_ident (p, _) -> p
-  | Tmod_apply (funct, arg, _coercion) when !Clflags.applicative_functors ->
+  | Tmod_apply (funct, arg, _coercion) ->
     Papply (path_of_module funct, path_of_module arg)
   | Tmod_constraint (mexp, _, _, _) -> path_of_module mexp
   | _ -> raise Not_a_path
diff --git a/compiler/syntax/src/res_ast_debugger.ml b/compiler/syntax/src/res_ast_debugger.ml
index c3b58b1b6c..5f041e7d85 100644
--- a/compiler/syntax/src/res_ast_debugger.ml
+++ b/compiler/syntax/src/res_ast_debugger.ml
@@ -742,7 +742,7 @@ module Sexp_ast = struct
       | Pexp_constraint (expr, typexpr) ->
         Sexp.list
           [Sexp.atom "Pexp_constraint"; expression expr; core_type typexpr]
-      | Pexp_coerce (expr, (), typexpr) ->
+      | Pexp_coerce (expr, typexpr) ->
         Sexp.list [Sexp.atom "Pexp_coerce"; expression expr; core_type typexpr]
       | Pexp_object_get _ -> Sexp.list [Sexp.atom "Pexp_object_get"]
       | Pexp_object_set (e1, _, e2) ->
diff --git a/compiler/syntax/src/res_comments_table.ml b/compiler/syntax/src/res_comments_table.ml
index 6591522507..ec01a935a7 100644
--- a/compiler/syntax/src/res_comments_table.ml
+++ b/compiler/syntax/src/res_comments_table.ml
@@ -1151,7 +1151,7 @@ and walk_expression expr t comments =
       attach t.leading expr.pexp_loc leading;
       walk_expression expr t inside;
       attach t.trailing expr.pexp_loc trailing
-  | Pexp_coerce (expr, (), typexpr) ->
+  | Pexp_coerce (expr, typexpr) ->
     let leading, inside, trailing = partition_by_loc comments expr.pexp_loc in
     attach t.leading expr.pexp_loc leading;
     walk_expression expr t inside;
diff --git a/compiler/syntax/src/res_printer.ml b/compiler/syntax/src/res_printer.ml
index 7ffe10d8fb..1701bd2ef5 100644
--- a/compiler/syntax/src/res_printer.ml
+++ b/compiler/syntax/src/res_printer.ml
@@ -3745,7 +3745,7 @@ and print_expression ~state (e : Parsetree.expression) cmt_tbl =
           Doc.space;
           print_cases ~state cases cmt_tbl;
         ]
-    | Pexp_coerce (expr, (), typ) ->
+    | Pexp_coerce (expr, typ) ->
       let doc_expr =
         print_expression_with_comments_and_parens ~state expr cmt_tbl
       in
diff --git a/packages/@rescript/belt/rescript.json b/packages/@rescript/belt/rescript.json
index 791e43cd34..5fb8388b9a 100644
--- a/packages/@rescript/belt/rescript.json
+++ b/packages/@rescript/belt/rescript.json
@@ -23,7 +23,6 @@
     "-bs-no-version-header",
     "-bs-no-check-div-by-zero",
     "-bs-cross-module-opt",
-    "-unsafe",
     "-w -3+50",
     "-warn-error A"
   ]
diff --git a/packages/@rescript/runtime/Primitive_array.res b/packages/@rescript/runtime/Primitive_array.res
index 7bfef9b575..b1be572549 100644
--- a/packages/@rescript/runtime/Primitive_array.res
+++ b/packages/@rescript/runtime/Primitive_array.res
@@ -7,13 +7,6 @@ let get = (xs, index) =>
     xs->Primitive_array_extern.getUnsafe(index)
   }
 
-let set = (xs, index, newval) =>
-  if index < 0 || index >= length(xs) {
-    throw(Invalid_argument("index out of bounds"))
-  } else {
-    xs->Primitive_array_extern.setUnsafe(index, newval)
-  }
-
 // Note: this is exposed to support syntax
 @new external makeUninitializedUnsafe: int => array<'a> = "Array"
 
diff --git a/packages/@rescript/runtime/lib/es6/Primitive_array.mjs b/packages/@rescript/runtime/lib/es6/Primitive_array.mjs
index b85c60c323..26c89564be 100644
--- a/packages/@rescript/runtime/lib/es6/Primitive_array.mjs
+++ b/packages/@rescript/runtime/lib/es6/Primitive_array.mjs
@@ -16,17 +16,6 @@ function get(xs, index) {
   return xs[index];
 }
 
-function set(xs, index, newval) {
-  if (index < 0 || index >= xs.length) {
-    throw {
-      RE_EXN_ID: "Invalid_argument",
-      _1: "index out of bounds",
-      Error: new Error()
-    };
-  }
-  xs[index] = newval;
-}
-
 function spread(arrays) {
   let arraysLength = arrays.length;
   let resultLength = 0;
@@ -48,7 +37,6 @@ function spread(arrays) {
 export {
   length,
   get,
-  set,
   spread,
 }
 /* No side effect */
diff --git a/packages/@rescript/runtime/lib/js/Primitive_array.cjs b/packages/@rescript/runtime/lib/js/Primitive_array.cjs
index d4eeabe9f7..97e51f5a2a 100644
--- a/packages/@rescript/runtime/lib/js/Primitive_array.cjs
+++ b/packages/@rescript/runtime/lib/js/Primitive_array.cjs
@@ -16,17 +16,6 @@ function get(xs, index) {
   return xs[index];
 }
 
-function set(xs, index, newval) {
-  if (index < 0 || index >= xs.length) {
-    throw {
-      RE_EXN_ID: "Invalid_argument",
-      _1: "index out of bounds",
-      Error: new Error()
-    };
-  }
-  xs[index] = newval;
-}
-
 function spread(arrays) {
   let arraysLength = arrays.length;
   let resultLength = 0;
@@ -47,6 +36,5 @@ function spread(arrays) {
 
 exports.length = length;
 exports.get = get;
-exports.set = set;
 exports.spread = spread;
 /* No side effect */
diff --git a/packages/@rescript/runtime/rescript.json b/packages/@rescript/runtime/rescript.json
index 1f2d69fd12..61a19dbf0f 100644
--- a/packages/@rescript/runtime/rescript.json
+++ b/packages/@rescript/runtime/rescript.json
@@ -30,7 +30,6 @@
     "-bs-no-version-header",
     "-bs-no-check-div-by-zero",
     "-bs-cross-module-opt",
-    "-unsafe",
     "-w -3+50",
     "-warn-error A"
   ]
diff --git a/tests/ERROR_VARIANTS.md b/tests/ERROR_VARIANTS.md
index 3901ef2c98..f6d6e471f2 100644
--- a/tests/ERROR_VARIANTS.md
+++ b/tests/ERROR_VARIANTS.md
@@ -564,6 +564,9 @@ The warning constructors listed in **Removed in `jono/remove-dead-errors`**
 were deleted. Their numeric warning slots remain holes; no warning number
 was reused.
 
+Warning 24 (`Bad_module_name`) was removed later for the same reason: it
+had no raise site. Its slot is likewise left unused.
+
 ### Live but no fixture yet
 
 These warnings have `prerr_warning` raise sites in `compiler/` and are
diff --git a/tools/src/migrate.ml b/tools/src/migrate.ml
index 6505c78be7..892d81ee76 100644
--- a/tools/src/migrate.ml
+++ b/tools/src/migrate.ml
@@ -56,7 +56,7 @@ module Expr_utils = struct
       true
     | Pexp_construct (_, {txt = [e]})
     | Pexp_constraint (e, _)
-    | Pexp_coerce (e, _, _)
+    | Pexp_coerce (e, _)
     | Pexp_let (_, _, e)
     | Pexp_sequence (e, _)
     | Pexp_letmodule (_, _, e)