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create 32 bit mex files from 64 bit matlab?

Sriram Swaminarayan — Fri, 02 Oct 2009 13:49:04 -0400

platform: osx, intel
matlab: 7.9.0.529 (R2009b), 64-bit (maci64), August 12, 2009

I want to create .mexmaci files using mex, but it looks like I have no way to create them using the mex that ships with this version of matlab.

Even if I use 'mex -arch maci ', it still only creates '.mexmaci64' files.

Is there a simple way around this, or do I have to keep a 32 bit version of matlab around to create the '.mexmaci' files?

Regards,
Sriram

Re: create 32 bit mex files from 64 bit matlab?

Dan Hensley — Tue, 06 Oct 2009 15:52:41 -0400

Sriram Swaminarayan wrote, On 10/2/2009 7:49 AM:
> platform: osx, intel
> matlab: 7.9.0.529 (R2009b), 64-bit (maci64), August 12, 2009
>
> I want to create .mexmaci files using mex, but it looks like I have no way to create them using the mex that ships with this version of matlab.
>
> Even if I use 'mex -arch maci ', it still only creates '.mexmaci64' files.
>
> Is there a simple way around this, or do I have to keep a 32 bit version of matlab around to create the '.mexmaci' files?

The latter. The mex file needs to link against the appropriate 32bit
Matlab libraries, which are only available with the 32bit installation.

Dan

Re: create 32 bit mex files from 64 bit matlab?

Rune Allnor — Tue, 06 Oct 2009 16:06:42 -0400

On 2 Okt, 15:49, "Sriram Swaminarayan" <sri...@lanl.gov> wrote:
> platform: osx, intel
> matlab: 7.9.0.529 (R2009b), 64-bit (maci64), August 12, 2009
>
> I want to create .mexmaci files using mex, but it looks like I have no way to create them using the mex that ships with this version of matlab.
>
> Even if I use 'mex -arch maci ', it still only creates '.mexmaci64' files.
>
> Is there a simple way around this, or do I have to keep a 32 bit version of matlab around to create the '.mexmaci' files?

It depends on the compiler, which needs to be able to
produce both 32-bit and 64-bit dlls and executables.
Once you have such a compiler (not all compilers can
do this), you will need to trick matlab/MEX to call the
compiler in 32-bit mode instead of 64-bit mode. Which
may or may not be possible.

Last, you might need to use matlab in 32-bit mode in
order to test the MEX file.

It might be most convenient to install a 32-bit
version of matlab on your 64-bit system, and do all
the 32-bit mex stuff under this version.

Provided, of course, that a 64-bit and a 32-bit matlab
can coexist on your system. Which may or may ot be the case.

Rune

Re: create 32 bit mex files from 64 bit matlab?

Bruno Luong — Tue, 06 Oct 2009 16:36:20 -0400

Dan Hensley <somewhere@over.there.invalid> wrote in message <hafp2q$dj4$1@news.eternal-september.org>...

> >
> > Is there a simple way around this, or do I have to keep a 32 bit version of matlab around to create the '.mexmaci' files?

I echo Dan here: you need to keep the 32-bit version of Matlab and compile with it.

Bruno

Re: create 32 bit mex files from 64 bit matlab?

Brian Arnold — Tue, 06 Oct 2009 18:36:52 -0400

Hi,

Installing both maci and maci64 together on a Mac is supported, but
cross-compiling a different architecture is not supported, and not
advised. You should always run the same architecture that you compile,
so that you can test that what you compiled works.

If you have both architectures installed, you can control the MATLAB
architecture to run using the "Open in 32-bit Mode" checkbox in the Get
Info window for the MATLAB_R2009b application in the Finder. To specify
the architecture from Terminal or xterm, use 'matlab -maci' or 'matlab
-maci64'.

With that said, it is actually possible to cross-compile :-). You only
need both maci and maci64 installed, and 64-bit hardware.

The environment variable MACI64 can be used to control the architecture
that the mex, mcc and matlab shell scripts default to. To change MEX to
compile 32-bit mexmaci from 64-bit MATLAB, set the MACI64 environment
variable to 0 before compiling with MEX. To change it back to compiling
64-bit mexmaci64, set it to something other than 0.

Doing this has many hazards associated with it, so it's not supported,
and my advice is that you always run the architecture you intend to
compile, so that you can test your compiled code.

Good luck,

- Brian

Rune Allnor wrote:
> On 2 Okt, 15:49, "Sriram Swaminarayan" <sri...@lanl.gov> wrote:
>> platform: osx, intel
>> matlab: 7.9.0.529 (R2009b), 64-bit (maci64), August 12, 2009
>>
>> I want to create .mexmaci files using mex, but it looks like I have no way to create them using the mex that ships with this version of matlab.
>>
>> Even if I use 'mex -arch maci ', it still only creates '.mexmaci64' files.
>>
>> Is there a simple way around this, or do I have to keep a 32 bit version of matlab around to create the '.mexmaci' files?
>
> It depends on the compiler, which needs to be able to
> produce both 32-bit and 64-bit dlls and executables.
> Once you have such a compiler (not all compilers can
> do this), you will need to trick matlab/MEX to call the
> compiler in 32-bit mode instead of 64-bit mode. Which
> may or may not be possible.
>
> Last, you might need to use matlab in 32-bit mode in
> order to test the MEX file.
>
> It might be most convenient to install a 32-bit
> version of matlab on your 64-bit system, and do all
> the 32-bit mex stuff under this version.
>
> Provided, of course, that a 64-bit and a 32-bit matlab
> can coexist on your system. Which may or may ot be the case.
>
> Rune