#6180: efficient creation of uninitialized float arrays.

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@14156 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

Changes

@@ -27,6 +27,7 @@ Standard library:
 - PR#4986: add List.sort_uniq and Set.of_list
 - PR#6148: speed improvement for Buffer (patch by John Whitington)
 - PR#6146: support "Unix.kill pid Sys.sigkill" under Windows
+- PR#6180: efficient creation of uninitialized float arrays
 
 Features wishes:
 - PR#4243: make the Makefiles parallelizable

byterun/array.c

@@ -135,6 +135,16 @@ CAMLprim value caml_array_unsafe_set(value array, value index, value newval)
     return caml_array_unsafe_set_addr(array, index, newval);
 }
 
+CAMLprim value caml_make_float_vect(value len)
+{
+  mlsize_t wsize = Long_val(len) * Double_wosize;
+  if (wsize == 0)
+    return Atom(0);
+  if (wsize > Max_wosize)
+    caml_invalid_argument("Array.make");
+  return caml_alloc(wsize, Double_array_tag);
+}
+
 CAMLprim value caml_make_vect(value len, value init)
 {
   CAMLparam2 (len, init);

stdlib/array.ml

@@ -25,6 +25,7 @@ external append_prim : 'a array -> 'a array -> 'a array = "caml_array_append"
 external concat : 'a array list -> 'a array = "caml_array_concat"
 external unsafe_blit :
   'a array -> int -> 'a array -> int -> int -> unit = "caml_array_blit"
+external make_float: int -> float array = "caml_make_float_vect"
 
 let init l f =
   if l = 0 then [||] else

stdlib/array.mli

@@ -150,6 +150,9 @@ val fold_right : ('b -> 'a -> 'a) -> 'b array -> 'a -> 'a
    [f a.(0) (f a.(1) ( ... (f a.(n-1) x) ...))],
    where [n] is the length of the array [a]. *)
 
+external make_float: int -> float array = "caml_make_float_vect"
+(** [Array.make_float n] returns a fresh float array of length [n],
+    with uninitialized data. *)
 
 (** {6 Sorting} *)