armfly/Libraries/CMSIS/DSP_Lib/Source/SupportFunctions/arm_fill_q15.c

/* ----------------------------------------------------------------------    
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
*    
* $Date:        31. July 2014
* $Revision: 	V1.4.4  
*    
* Project: 	    CMSIS DSP Library    
* Title:		arm_fill_q15.c    
*    
* Description:	Fills a constant value into a Q15 vector.   
*    
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*  
* Redistribution and use in source and binary forms, with or without 
* modification, are permitted provided that the following conditions
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*   - Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*   - Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in
*     the documentation and/or other materials provided with the 
*     distribution.
*   - Neither the name of ARM LIMITED nor the names of its contributors
*     may be used to endorse or promote products derived from this
*     software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* -------------------------------------------------------------------- */

#include "arm_math.h"

/**    
 * @ingroup groupSupport    
 */

/**    
 * @addtogroup Fill    
 * @{    
 */

/**    
 * @brief Fills a constant value into a Q15 vector.    
 * @param[in]       value input value to be filled   
 * @param[out]      *pDst points to output vector    
 * @param[in]       blockSize length of the output vector   
 * @return none.    
 *    
 */

void arm_fill_q15(
  q15_t value,
  q15_t * pDst,
  uint32_t blockSize)
{
  uint32_t blkCnt;                               /* loop counter */

#ifndef ARM_MATH_CM0_FAMILY

  /* Run the below code for Cortex-M4 and Cortex-M3 */

  q31_t packedValue;                             /* value packed to 32 bits */


  /*loop Unrolling */
  blkCnt = blockSize >> 2u;

  /* Packing two 16 bit values to 32 bit value in order to use SIMD */
  packedValue = __PKHBT(value, value, 16u);

  /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.    
   ** a second loop below computes the remaining 1 to 3 samples. */
  while(blkCnt > 0u)
  {
    /* C = value */
    /* Fill the value in the destination buffer */
    *__SIMD32(pDst)++ = packedValue;
    *__SIMD32(pDst)++ = packedValue;

    /* Decrement the loop counter */
    blkCnt--;
  }

  /* If the blockSize is not a multiple of 4, compute any remaining output samples here.    
   ** No loop unrolling is used. */
  blkCnt = blockSize % 0x4u;

#else

  /* Run the below code for Cortex-M0 */

  /* Loop over blockSize number of values */
  blkCnt = blockSize;

#endif /* #ifndef ARM_MATH_CM0_FAMILY */

  while(blkCnt > 0u)
  {
    /* C = value */
    /* Fill the value in the destination buffer */
    *pDst++ = value;

    /* Decrement the loop counter */
    blkCnt--;
  }
}

/**    
 * @} end of Fill group    
 */