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Date: -- (:)
From: Jean-Christophe Filliatre <Jean-Christophe.Filliatre@l...>
Subject: Re: [Caml-list] Gripes with array

Jon Harrop writes:
 > 
 > Does anyone have any pointers to information about the origin of the size 
 > limit for arrays? I assume it is something to do with the garbage collector 
 > using a fixed-size tag instead of a variable-size one but I'd be interested 
 > in the details.

In ocaml sources, the  file byterun/mlvalues.h gives all details about
the  block  header structure.  There  you can  see  that,  on 32  bits
architecture,  the block size  (in words)  is stored  on 22  bits. And
indeed Sys.max_array_length is equal to 2^22-1.

But I must  agree with you: this is definitely too  small and we could
imagine  that, when the  tag says  a block  is an  array, the  size is
stored within the first (or the last) field instead.

-- 
Jean-Christophe Filliātre


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