[Caml-list] detecting 32/64 bit from C

[Caml-list] detecting 32/64 bit from C

[Markus Weißmann]

Hello,

is there some "official" way to detect -- from C -- if OCaml was 
compiled for 32 or 64 bit?
I'd love to have something like a #define that either says 32 or 64 
bit;
I need to know at compile time if the OCaml system uses 31 or 63 bit 
sized integers (in the C code).
I don't care what the underlying OS or hardware does, but just what 
OCaml is using.

Btw.: Is [Sys.word_size = 32] for 32 bit OCaml compilers on 64 bit 
machines?

Regards
-Markus

-- 
Markus Weißmann, M.Sc.
Technische Universität München
Institut für Informatik
Boltzmannstr. 3
D-85748 Garching
Germany
http://wwwknoll.in.tum.de/

Re: [Caml-list] detecting 32/64 bit from C

[Adrien Nader]

On Tue, Oct 13, 2015, Markus Weißmann wrote:
> Hello,
> 
> is there some "official" way to detect -- from C -- if OCaml was
> compiled for 32 or 64 bit?
> I'd love to have something like a #define that either says 32 or 64
> bit;
> I need to know at compile time if the OCaml system uses 31 or 63 bit
> sized integers (in the C code).
> I don't care what the underlying OS or hardware does, but just what
> OCaml is using.
> 
> Btw.: Is [Sys.word_size = 32] for 32 bit OCaml compilers on 64 bit
> machines?

Hi,

I believe config.h has the info you want:
  #define ARCH_SIXTYFOUR // for instance

Note how it's installed under $(libdir) and not $(includedir): its
content is set at configure-time and depends on the architecture that
ocaml has been configured for.

-- 
Adrien Nader

Re: [Caml-list] detecting 32/64 bit from C

[Gerd Stolpmann]

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Am Dienstag, den 13.10.2015, 14:24 +0200 schrieb Adrien Nader:
> On Tue, Oct 13, 2015, Markus Weißmann wrote:
> > Hello,
> > 
> > is there some "official" way to detect -- from C -- if OCaml was
> > compiled for 32 or 64 bit?
> > I'd love to have something like a #define that either says 32 or 64
> > bit;
> > I need to know at compile time if the OCaml system uses 31 or 63 bit
> > sized integers (in the C code).
> > I don't care what the underlying OS or hardware does, but just what
> > OCaml is using.
> > 
> > Btw.: Is [Sys.word_size = 32] for 32 bit OCaml compilers on 64 bit
> > machines?

Yes.

> 
> Hi,
> 
> I believe config.h has the info you want:
>   #define ARCH_SIXTYFOUR // for instance

Exactly.

> Note how it's installed under $(libdir) and not $(includedir): its
> content is set at configure-time and depends on the architecture that
> ocaml has been configured for.

config.h should be available in $stdlib/caml. It is included from the
other header files.

Gerd

> -- 
> Adrien Nader
> 

-- 
------------------------------------------------------------
Gerd Stolpmann, Darmstadt, Germany    gerd@gerd-stolpmann.de
My OCaml site:          http://www.camlcity.org
Contact details:        http://www.camlcity.org/contact.html
Company homepage:       http://www.gerd-stolpmann.de
------------------------------------------------------------


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Re: [Caml-list] detecting 32/64 bit from C

[Markus Weißmann]

Perfect -- thanks a lot!

-Markus

On 2015-10-13 16:07, Gerd Stolpmann wrote:
> Am Dienstag, den 13.10.2015, 14:24 +0200 schrieb Adrien Nader:
>> On Tue, Oct 13, 2015, Markus Weißmann wrote:
>> > Hello,
>> >
>> > is there some "official" way to detect -- from C -- if OCaml was
>> > compiled for 32 or 64 bit?
>> > I'd love to have something like a #define that either says 32 or 
>> 64
>> > bit;
>> > I need to know at compile time if the OCaml system uses 31 or 63 
>> bit
>> > sized integers (in the C code).
>> > I don't care what the underlying OS or hardware does, but just 
>> what
>> > OCaml is using.
>> >
>> > Btw.: Is [Sys.word_size = 32] for 32 bit OCaml compilers on 64 bit
>> > machines?
>
> Yes.
>
>>
>> Hi,
>>
>> I believe config.h has the info you want:
>>   #define ARCH_SIXTYFOUR // for instance
>
> Exactly.
>
>> Note how it's installed under $(libdir) and not $(includedir): its
>> content is set at configure-time and depends on the architecture 
>> that
>> ocaml has been configured for.
>
> config.h should be available in $stdlib/caml. It is included from the
> other header files.
>
> Gerd
>
>> --
>> Adrien Nader
>>

-- 
Markus Weißmann, M.Sc.
Technische Universität München
Institut für Informatik
Boltzmannstr. 3
D-85748 Garching
Germany
http://wwwknoll.in.tum.de/