.. _prngenrdrand:


PRNGenRDRAND
============


Generates a pseudorandom unsigned Big Number of the specified bit length
using the RDRAND instruction.


Syntax
------


IppStatus ippsPRNGenRDRAND(Ipp32u\* pRand, int nBits, void\* pCtx);


Include Files
-------------


``ippcp.h``


Parameters
----------


.. list-table:: 
   :header-rows: 0

   * -     pRand   
     -  Pointer to the output pseudorandom unsigned integer big number.
   * -     nBits   
     -  The number of generated pseudorandom bits.
   * -     pCtx   
     -  Pointer to the IppsPRNGState context. This pointer is unused and can be NULL.




Description
-----------


The function generates a pseudorandom unsigned integer big number of the
specified nBits length. The generation is based on the RDRAND
instruction available on latest Intel® processors
`[INTEL_ARCH] <bibliography.html>`__.


.. admonition:: Product and Performance Information 

   Performance varies by use, configuration and other factors. Learn more at `www.intel.com/PerformanceIndex <https://www.intel.com/PerformanceIndex>`_.
   Notice revision #20201201 



Return Values
-------------


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   :header-rows: 0

   * -     ippStsNoErr   
     -  Indicates no error. Any other value indicates an error or warning.
   * -     ippStsNullPtrErr   
     -  Indicates an error condition if any of the specified pointers is NULL.
   * -     ippStsContextMatchErr   
     -  Indicates an error condition if the context parameter does not match the operation.
   * -     ippStsLengthErr   
     -  Indicates an error condition if nBits is less than 1.
   * -     ippStsNotSupportedModeErr   
     -  Indicates an error condition if the RDRAND instruction is not available on the target processor.