= MEX files on 64-bits architectures =

Since Matlab 7.3, the following types are defined for MEX-files:
 * {{{mwSize}}}: represents size values, such as array dimensions and number of elements
 * {{{mwIndex}}}: represents index values, such as indices into arrays

On 32-bits machines, these types are simply aliases for {{{int}}}.

On 64-bits machines, it depends on whether one gives the {{{-largeArrayDims}}} for the MEX command:
 * without {{{-largeArrayDims}}}, these types are {{{int}}} (and therefore 32 bits)
 * with {{{-largeArrayDims}}}, these types are {{{size_t}}}, which is an alias for {{{unsigned long}}} (and therefore 64 bits)

See [[http://www.mathworks.fr/access/helpdesk/help/techdoc/rn/bqt6wtq.html|Matlab 7.3 release notes]] for more details.

Since it is mandatory to use the {{{-largeArrayDims}}} when using sparse arrays on 64-bits architectures (and since this option will probably be the default in future versions of Matlab), Dynare's MEX-files are compiled with this option on 64-bits architectures.

This implies that, when coding MEX-files for Dynare, one should not expect that {{{mwSize}}}, {{{mwIndex}}} and {{{int}}} are synonymous.

In particular, appropriate type conversions should be made, especially when pointers are concerned. Such conversions are, for example, used in {{{A_times_B_kronecker_C}}}.