Comment author: administrator

I get the following behaviour in a custom toplevel with bigarray.cma
built in:

open Bigarray;;

let a = Array1.create float32 c_layout 4;;

val a : (float, Bigarray.float32_elt, Bigarray.c_layout)
Bigarray.Array1.t =

a.{0} <- 2.0;;

• : unit = ()

a.{0};;

The external function `bigarray_get_1' is not available

It looks as though bigarray.ml and bigarray.mli refer to
"%bigarray_ref_1", but the C library function is called
"bigarray_get_1". The same thing happens for Array2 and Array3 as well.

Is this a bug, or have I done something wrong?

It is a bug. I enclose a small patch that fixes it. (After applying it, go to
otherlibs/bigarrays, make all allopt, make install installopt.)

Also, why do some (but not all) references to external C functions begin
with a '%' sign? (apologies if this is in the documentation somewhere)

It's not documented. Those '%' primitives correspond to primitive operations
that are treated specially by the compiler: some of them are expanded
into machine instructions, without calling any C function; others are
either expanded into machine instructions or into a call to a generic
C function, depending on the amount of type information available.

This is the case for "%bigarray_ref_1": it may be turned into a call
to "bigarray_get_1", or expanded in-line if enough type information is
known. However, this confused the "ocamlmktop" command, which,
basically, didn't see the implicit reference to "bigarray_get_1".

Thanks for the bug report.

Best regards,

• Xavier Leroy

Index: csl/otherlibs/bigarray/bigarray.ml
diff -c csl/otherlibs/bigarray/bigarray.ml:1.5 csl/otherlibs/bigarray/bigarray.ml:1.6
*** csl/otherlibs/bigarray/bigarray.ml:1.5 Mon Feb 28 16:46:28 2000
--- csl/otherlibs/bigarray/bigarray.ml Fri Apr 28 13:32:07 2000

*** 10,16 ****
(* *)
(***********************************************************************)

! (* $Id: bigarray.ml,v 1.5 2000/02/28 15:46:28 xleroy Exp $ *)

(* Module [Bigarray]: large, multi-dimensional, numerical arrays *)

--- 10,16 ----
(* *)
(***********************************************************************)

! (* $Id: bigarray.ml,v 1.6 2000/04/28 11:32:07 xleroy Exp $ *)

(* Module [Bigarray]: large, multi-dimensional, numerical arrays *)

*** 187,190 ****
--- 187,200 ----
if Genarray.num_dims a = 2 then a else invalid_arg "Bigarray.array2_of_genarray"
let array3_of_genarray a =
if Genarray.num_dims a = 3 then a else invalid_arg "Bigarray.array3_of_genarray"
+

• (* Force bigarray_get_{1,2,3,N} to be linked in, since we don't refer
• to those primitives directly in this file *)
• let _ =
• let getN = Genarray.get in
• let get1 = Array1.get in
• let get2 = Array2.get in
• let get3 = Array3.get in
• ()

Comment author: administrator

Fixed on 2000-04-28 by Xavier.