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Array Size Restrictions for Code Generation

For code generation, the maximum number of elements of an array is constrained by the code generator and the target hardware.

For fixed-size arrays and variable-size arrays that use static memory allocation, the maximum number of elements is the smaller of:

  • intmax('int32').

  • The largest integer that fits in the C int data type on the target hardware.

For variable-size arrays that use dynamic memory allocation, the maximum number of elements is the smaller of:

  • intmax('int32').

  • The largest power of 2 that fits in the C int data type on the target hardware.

These restrictions apply even on a 64-bit platform.

For a fixed-size array, if the number of elements exceeds the maximum, the code generator reports an error at compile time.

For a variable-size array, if the number of elements exceeds the maximum at run time, the error checking behavior depends on the code generation target:

  • While running the code generated by using the codegen (MATLAB Coder) command, the fiaccel (Fixed-Point Designer) command, or the MATLAB® Coder™ app, if run-time error checks are enabled, the generated code reports an error. By default, run-time error checks are enabled for MEX code and disabled for standalone C/C++ code.

  • During simulation of a MATLAB Function block, the software reports an error. Generated standalone code for MATLAB Function blocks cannot report array size violations.