Revert "removed small int parts"

This moves commit e0b8691 into this PR.

Author: jvanburen

backend/arm64/cfg_selection.ml

@@ -171,7 +171,7 @@ class selector =
     method! insert_move_extcall_arg env ty_arg src dst =
       let ty_arg_is_int32 =
         match ty_arg with
-        | XInt32 -> true
+        | XInt8 | XInt16 | XInt32 -> true
         | XInt | XInt64 | XFloat32 | XFloat | XVec128 -> false
       in
       if macosx && ty_arg_is_int32 && is_stack_slot dst

backend/arm64/proc.ml

@@ -297,7 +297,7 @@ let external_calling_conventions
     begin match ty_arg with
     | XInt | XInt64 ->
         loc.(i) <- [| loc_int last_int make_stack int ofs |]
-    | XInt32 ->
+    | XInt32 | XInt16 | XInt8 ->
         loc.(i) <- [| loc_int32 last_int make_stack int ofs |]
     | XFloat ->
         loc.(i) <- [| loc_float last_float make_stack float ofs |]

backend/arm64/selection.ml

@@ -157,7 +157,12 @@ class selector =
       | _ -> super#select_operation op args dbg
 
     method! insert_move_extcall_arg env ty_arg src dst =
-      if macosx && ty_arg = XInt32 && is_stack_slot dst
+      let ty_arg_is_int32 =
+        match ty_arg with
+        | XInt8 | XInt16 | XInt32 -> true
+        | XInt | XInt64 | XFloat32 | XFloat | XVec128 -> false
+      in
+      if macosx && ty_arg_is_int32 && is_stack_slot dst
       then self#insert env (Iop (Ispecific Imove32)) src dst
       else self#insert_moves env src dst
   end

backend/cmm.ml

@@ -1,3 +1,4 @@
+# 1 "backend/cmm.ml"
 (**************************************************************************)
 (*                                                                        *)
 (*                                 OCaml                                  *)
@@ -107,6 +108,8 @@ let ge_component comp1 comp2 =
 
 type exttype =
   | XInt
+  | XInt8
+  | XInt16
   | XInt32
   | XInt64
   | XFloat32
@@ -115,6 +118,8 @@ type exttype =
 
 let machtype_of_exttype = function
   | XInt -> typ_int
+  | XInt8 -> typ_int
+  | XInt16 -> typ_int
   | XInt32 -> typ_int
   | XInt64 -> typ_int
   | XFloat -> typ_float
@@ -611,21 +616,19 @@ let equal_machtype_component (left : machtype_component) (right : machtype_compo
   | Float32, (Val | Addr | Int | Float | Vec128 | Valx2) ->
     false
 
-let equal_exttype left right =
-  match left, right with
-  | XInt, XInt -> true
-  | XInt32, XInt32 -> true
-  | XInt64, XInt64 -> true
-  | XFloat32, XFloat32 -> true
-  | XFloat, XFloat -> true
-  | XVec128, XVec128 -> true
-  | XInt, (XInt32 | XInt64 | XFloat | XFloat32 | XVec128)
-  | XInt32, (XInt | XInt64 | XFloat | XFloat32 | XVec128)
-  | XInt64, (XInt | XInt32 | XFloat | XFloat32 | XVec128)
-  | XFloat, (XInt | XInt32 | XFloat32 | XInt64 | XVec128)
-  | XVec128, (XInt | XInt32 | XInt64 | XFloat | XFloat32)
-  | XFloat32, (XInt | XInt32 | XInt64 | XFloat | XVec128) ->
-    false
+let equal_exttype
+      ((XInt
+       | XInt8
+       | XInt16
+       | XInt32
+       | XInt64
+       | XFloat32
+       | XFloat
+       | XVec128) as left)
+      right
+  =
+  (* we can use polymorphic compare as long as exttype is all constant constructors *)
+  left = right
 
 let equal_vec128_type v1 v2 =
   match v1, v2 with

backend/cmm.mli

@@ -75,6 +75,8 @@ val ge_component
 
 type exttype =
   | XInt                                (**r OCaml value, word-sized integer *)
+  | XInt8                               (**r 8-bit integer *)
+  | XInt16                              (**r 16-bit integer  *)
   | XInt32                              (**r 32-bit integer *)
   | XInt64                              (**r 64-bit integer  *)
   | XFloat32                            (**r single-precision FP number *)

backend/printcmm.ml

@@ -49,6 +49,8 @@ let machtype ppf mty =
 
 let exttype ppf = function
   | XInt -> fprintf ppf "int"
+  | XInt8 -> fprintf ppf "int8"
+  | XInt16 -> fprintf ppf "int16"
   | XInt32 -> fprintf ppf "int32"
   | XInt64 -> fprintf ppf "int64"
   | XFloat -> fprintf ppf "float"

middle_end/flambda2/to_cmm/to_cmm_shared.ml

@@ -306,6 +306,8 @@ module Update_kind = struct
   type kind =
     | Pointer
     | Immediate
+    | Naked_int8
+    | Naked_int16
     | Naked_int32
     | Naked_int64
     | Naked_float
@@ -329,8 +331,8 @@ module Update_kind = struct
 
   let field_size_in_words t =
     match t.kind with
-    | Pointer | Immediate | Naked_int32 | Naked_int64 | Naked_float
-    | Naked_float32 ->
+    | Pointer | Immediate | Naked_int8 | Naked_int16 | Naked_int32 | Naked_int64
+    | Naked_float | Naked_float32 ->
       1
     | Naked_vec128 -> 2
 
@@ -348,6 +350,10 @@ module Update_kind = struct
 
   let naked_vec128s = { kind = Naked_vec128; stride = 16 }
 
+  let naked_int8_fields = { kind = Naked_int8; stride = Arch.size_addr }
+
+  let naked_int16_fields = { kind = Naked_int16; stride = Arch.size_addr }
+
   let naked_int32_fields = { kind = Naked_int32; stride = Arch.size_addr }
 
   let naked_float32_fields = { kind = Naked_float32; stride = Arch.size_addr }
@@ -372,8 +378,8 @@ let make_update env res dbg ({ kind; stride } : Update_kind.t) ~symbol var
         | Immediate ->
           (* See [caml_initialize]; we can avoid this function in this case. *)
           None
-        | Naked_int32 | Naked_int64 | Naked_float | Naked_float32 | Naked_vec128
-          ->
+        | Naked_int8 | Naked_int16 | Naked_int32 | Naked_int64 | Naked_float
+        | Naked_float32 | Naked_vec128 ->
           (* The GC never sees these fields, so we can avoid using
              [caml_initialize]. This is important as it significantly reduces
              the complexity of the statically-allocated inconstant unboxed int32
@@ -389,6 +395,11 @@ let make_update env res dbg ({ kind; stride } : Update_kind.t) ~symbol var
         match kind with
         | Pointer -> Word_val
         | Immediate -> Word_int
+        | Naked_int8 | Naked_int16 ->
+          (* CR layouts v5.1: we only support small integers in being
+             sign-extended in word fields *)
+          assert (stride = Arch.size_addr);
+          Word_int
         | Naked_int32 ->
           (* Cmm expressions representing int32 values are always sign extended.
              By using [Word_int] in the "fields" cases (see [Update_kind],

middle_end/flambda2/to_cmm/to_cmm_shared.mli

@@ -113,6 +113,12 @@ module Update_kind : sig
 
   val tagged_immediates : t
 
+  (** Assumes each field is a word; the byte offset is [index * size_addr]. *)
+  val naked_int8_fields : t
+
+  (** Assumes each field is a word; the byte offset is [index * size_addr]. *)
+  val naked_int16_fields : t
+
   (** Tightly packed; the byte offset is [index * 4].  ([index] is as for
       [make_update], below.) *)
   val naked_int32s : t