only in patch2:
unchanged:
--- ocaml-3.11.1.orig/byterun/compatibility.h
+++ ocaml-3.11.1/byterun/compatibility.h
@@ -324,6 +324,7 @@
 #define BIGARRAY_NATIVE_INT CAML_BA_NATIVE_INT
 #define BIGARRAY_COMPLEX32 CAML_BA_COMPLEX32
 #define BIGARRAY_COMPLEX64 CAML_BA_COMPLEX64
+#define BIGARRAY_INT31 CAML_BA_INT31
 #define BIGARRAY_KIND_MASK CAML_BA_KIND_MASK
 #define caml_bigarray_layout caml_ba_layout
 #define BIGARRAY_C_LAYOUT CAML_BA_C_LAYOUT
only in patch2:
unchanged:
--- ocaml-3.11.1.orig/bytecomp/typeopt.ml
+++ ocaml-3.11.1/bytecomp/typeopt.ml
@@ -118,7 +118,8 @@
    "int_elt", Pbigarray_caml_int;
    "nativeint_elt", Pbigarray_native_int;
    "complex32_elt", Pbigarray_complex32;
-   "complex64_elt", Pbigarray_complex64]
+   "complex64_elt", Pbigarray_complex64;
+   "int31_elt", Pbigarray_int31]
 
 let layout_table =
   ["c_layout", Pbigarray_c_layout;
only in patch2:
unchanged:
--- ocaml-3.11.1.orig/bytecomp/printlambda.ml
+++ ocaml-3.11.1/bytecomp/printlambda.ml
@@ -72,6 +72,7 @@
      | Pbigarray_uint8 -> "uint8"
      | Pbigarray_sint16 -> "sint16"
      | Pbigarray_uint16 -> "uint16"
+     | Pbigarray_int31 -> "int31"
      | Pbigarray_int32 -> "int32"
      | Pbigarray_int64 -> "int64"
      | Pbigarray_caml_int -> "camlint"
only in patch2:
unchanged:
--- ocaml-3.11.1.orig/bytecomp/lambda.mli
+++ ocaml-3.11.1/bytecomp/lambda.mli
@@ -102,6 +102,7 @@
   | Pbigarray_int32 | Pbigarray_int64
   | Pbigarray_caml_int | Pbigarray_native_int
   | Pbigarray_complex32 | Pbigarray_complex64
+  | Pbigarray_int31
 
 and bigarray_layout =
     Pbigarray_unknown_layout
only in patch2:
unchanged:
--- ocaml-3.11.1.orig/bytecomp/lambda.ml
+++ ocaml-3.11.1/bytecomp/lambda.ml
@@ -102,6 +102,7 @@
   | Pbigarray_int32 | Pbigarray_int64
   | Pbigarray_caml_int | Pbigarray_native_int
   | Pbigarray_complex32 | Pbigarray_complex64
+  | Pbigarray_int31
 
 and bigarray_layout =
     Pbigarray_unknown_layout
only in patch2:
unchanged:
--- ocaml-3.11.1.orig/asmcomp/cmmgen.ml
+++ ocaml-3.11.1/asmcomp/cmmgen.ml
@@ -520,6 +520,7 @@
   | Pbigarray_native_int -> size_int
   | Pbigarray_complex32 -> 8
   | Pbigarray_complex64 -> 16
+  | Pbigarray_int31 -> 4
 
 let bigarray_indexing unsafe elt_kind layout b args dbg =
   let check_bound a1 a2 k =
@@ -561,6 +562,7 @@
   | Pbigarray_uint8 -> Byte_unsigned
   | Pbigarray_sint16 -> Sixteen_signed
   | Pbigarray_uint16 -> Sixteen_unsigned
+  | Pbigarray_int31 -> Thirtytwo_signed
   | Pbigarray_int32 -> Thirtytwo_signed
   | Pbigarray_int64 -> Word
   | Pbigarray_caml_int -> Word
@@ -908,6 +910,7 @@
           | Pbigarray_int32 -> box_int Pint32 elt
           | Pbigarray_int64 -> box_int Pint64 elt
           | Pbigarray_native_int -> box_int Pnativeint elt
+          | Pbigarray_int31 -> force_tag_int elt
           | Pbigarray_caml_int -> force_tag_int elt
           | _ -> tag_int elt
           end
only in patch2:
unchanged:
--- ocaml-3.11.1.orig/otherlibs/bigarray/bigarray.h
+++ ocaml-3.11.1/otherlibs/bigarray/bigarray.h
@@ -46,6 +46,7 @@
   CAML_BA_NATIVE_INT,       /* Platform-native long integers (32 or 64 bits) */
   CAML_BA_COMPLEX32,           /* Single-precision complex */
   CAML_BA_COMPLEX64,           /* Double-precision complex */
+  CAML_BA_INT31,               /* Small Caml-style integers (signed 31 bits) */
   CAML_BA_KIND_MASK = 0xFF     /* Mask for kind in flags field */
 };
 
only in patch2:
unchanged:
--- ocaml-3.11.1.orig/otherlibs/bigarray/bigarray_stubs.c
+++ ocaml-3.11.1/otherlibs/bigarray/bigarray_stubs.c
@@ -51,7 +51,8 @@
   2 /*SINT16*/, 2 /*UINT16*/,
   4 /*INT32*/, 8 /*INT64*/,
   sizeof(value) /*CAML_INT*/, sizeof(value) /*NATIVE_INT*/,
-  8 /*COMPLEX32*/, 16 /*COMPLEX64*/
+  8 /*COMPLEX32*/, 16 /*COMPLEX64*/,
+  4 /*INT31*/
 };
 
 /* Compute the number of bytes for the elements of a big array */
@@ -278,6 +279,8 @@
     return Val_int(((int16 *) b->data)[offset]);
   case CAML_BA_UINT16:
     return Val_int(((uint16 *) b->data)[offset]);
+  case CAML_BA_INT31:
+    return Val_int(((int32 *) b->data)[offset]);
   case CAML_BA_INT32:
     return caml_copy_int32(((int32 *) b->data)[offset]);
   case CAML_BA_INT64:
@@ -377,6 +380,8 @@
   case CAML_BA_SINT16:
   case CAML_BA_UINT16:
     ((int16 *) b->data)[offset] = Int_val(newval); break;
+  case CAML_BA_INT31:
+    ((int32 *) b->data)[offset] = Int_val(newval); break;
   case CAML_BA_INT32:
     ((int32 *) b->data)[offset] = Int32_val(newval); break;
   case CAML_BA_INT64:
@@ -583,6 +588,8 @@
     DO_INTEGER_COMPARISON(int16);
   case CAML_BA_UINT16:
     DO_INTEGER_COMPARISON(uint16);
+  case CAML_BA_INT31:
+    DO_INTEGER_COMPARISON(int32);
   case CAML_BA_INT32:
     DO_INTEGER_COMPARISON(int32);
   case CAML_BA_INT64:
@@ -641,6 +648,7 @@
   }
   case CAML_BA_FLOAT32:
   case CAML_BA_COMPLEX32:
+  case CAML_BA_INT31:
   case CAML_BA_INT32:
 #ifndef ARCH_SIXTYFOUR
   case CAML_BA_CAML_INT:
@@ -734,6 +742,7 @@
   case CAML_BA_UINT16:
     caml_serialize_block_2(b->data, num_elts); break;
   case CAML_BA_FLOAT32:
+  case CAML_BA_INT31:
   case CAML_BA_INT32:
     caml_serialize_block_4(b->data, num_elts); break;
   case CAML_BA_COMPLEX32:
@@ -806,6 +815,7 @@
   case CAML_BA_UINT16:
     caml_deserialize_block_2(b->data, num_elts); break;
   case CAML_BA_FLOAT32:
+  case CAML_BA_INT31:
   case CAML_BA_INT32:
     caml_deserialize_block_4(b->data, num_elts); break;
   case CAML_BA_COMPLEX32:
@@ -996,6 +1006,12 @@
     for (p = b->data; num_elts > 0; p++, num_elts--) *p = init;
     break;
   }
+  case CAML_BA_INT31: {
+    int32 init = Int_val(vinit);
+    int32 * p;
+    for (p = b->data; num_elts > 0; p++, num_elts--) *p = init;
+    break;
+  }
   case CAML_BA_INT32: {
     int32 init = Int32_val(vinit);
     int32 * p;
only in patch2:
unchanged:
--- ocaml-3.11.1.orig/otherlibs/bigarray/bigarray.ml
+++ ocaml-3.11.1/otherlibs/bigarray/bigarray.ml
@@ -33,6 +33,7 @@
 type float64_elt
 type complex32_elt
 type complex64_elt
+type int31_elt
 
 (* Keep those constants in sync with the caml_ba_kind enumeration
    in bigarray.h *)
@@ -50,6 +51,7 @@
 let char = int8_unsigned
 let complex32 = 10
 let complex64 = 11
+let int31 = 12
 
 type 'a layout = int
 
only in patch2:
unchanged:
--- ocaml-3.11.1.orig/otherlibs/bigarray/bigarray.mli
+++ ocaml-3.11.1/otherlibs/bigarray/bigarray.mli
@@ -49,6 +49,8 @@
    ({!Bigarray.int16_signed_elt} or {!Bigarray.int16_unsigned_elt}),
 - Caml integers (signed, 31 bits on 32-bit architectures,
    63 bits on 64-bit architectures) ({!Bigarray.int_elt}),
+- Small Caml integers (signed, 31 bits on 32-bit architectures,
+    32 bits on 64-bit architectures) ({!Bigarray.int31_elt}),
 - 32-bit signed integer ({!Bigarray.int32_elt}),
 - 64-bit signed integers ({!Bigarray.int64_elt}),
 - platform-native signed integers (32 bits on 32-bit architectures,
@@ -70,6 +72,7 @@
 type int32_elt
 type int64_elt
 type nativeint_elt
+type int31_elt
 
 type ('a, 'b) kind
 (** To each element kind is associated a Caml type, which is
@@ -115,6 +118,9 @@
 val int : (int, int_elt) kind
 (** See {!Bigarray.char}. *)
 
+val int31 : (int, int31_elt) kind
+(** See {!Bigarray.char}. *)
+
 val int32 : (int32, int32_elt) kind
 (** See {!Bigarray.char}. *)
 
@@ -132,7 +138,7 @@
    {!Complex.t}.  Big arrays of
    integer kinds are accessed using the smallest Caml integer
    type large enough to represent the array elements:
-   [int] for 8- and 16-bit integer bigarrays, as well as Caml-integer
+    [int] for 8-, 16- and 31-bit integer bigarrays, as well as Caml-integer
    bigarrays; [int32] for 32-bit integer bigarrays; [int64]
    for 64-bit integer bigarrays; and [nativeint] for
    platform-native integer bigarrays.  Finally, big arrays of