text: /* ----------------------------------------------------------------------    
  * Copyright (C) 2010-2014 ARM Limited. All rights reserved.    
  *    
  * $Date:        19. March 2015
  * $Revision: 	V.1.4.5
  *    
  * Project: 	    CMSIS DSP Library    
  * Title:		arm_dot_prod_q15.c    
  *    
  * Description:	Q15 dot product.    
  *    
  * 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
  * are met:
  *   - 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
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * 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,
  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  
   Modifications 2017  Mostafa Saleh       (Ported to RISC-V PULPino)
  * -------------------------------------------------------------------- */
  
  #include <riscv_dsp/riscv_math.h>
  
  /**    
   * @ingroup groupMath    
   */
  
  /**    
   * @addtogroup dot_prod    
   * @{    
   */
  
  /**    
   * @brief Dot product of Q15 vectors.    
   * @param[in]       *pSrcA points to the first input vector    
   * @param[in]       *pSrcB points to the second input vector    
   * @param[in]       blockSize number of samples in each vector    
   * @param[out]      *result output result returned here    
   * @return none.    
   *    
   * <b>Scaling and Overflow Behavior:</b>    
   * \par    
   * The intermediate multiplications are in 1.15 x 1.15 = 2.30 format and these    
   * results are added to a 64-bit accumulator in 34.30 format.    
   * Nonsaturating additions are used and given that there are 33 guard bits in the accumulator    
   * there is no risk of overflow.    
   * The return result is in 34.30 format.    
   */
  
  void riscv_dot_prod_q15(
    q15_t * pSrcA,
    q15_t * pSrcB,
    uint32_t blockSize,
    q63_t * result)
  {
    q63_t sum = 0;                                 /* Temporary result storage */
    uint32_t blkCnt;                               /* loop counter */
  
  #if defined (USE_DSP_RISCV)
  
    shortV *VectInA;
    shortV *VectInB;
  
    /*loop Unrolling */
    blkCnt = blockSize >> 1u;
  
    while (blkCnt > 0u)
    {
      /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
      /*read 2 elements from each buffer */
      VectInA =  (shortV*)pSrcA;
      VectInB =  (shortV*)pSrcB;
      /*increment source buffers */
      pSrcA+=2;
      pSrcB+=2;
      /*dotpv2 to perform dot product, then accumulate the sum*/
      sum += dotpv2(*VectInA, *VectInB);
  
      /* Decrement the loop counter */
      blkCnt--;
    }
  
    blkCnt = blockSize % 0x2u;
   /*the remaning sample if vector size is odd*/
    while (blkCnt > 0u) 
    {
      sum +=  (q63_t) ((q31_t) * pSrcA++ * *pSrcB++);
      /* Decrement the loop counter */
      blkCnt--;
    }
  
  
  #else
    /* Initialize blkCnt with number of samples */
    blkCnt = blockSize;
  
    while(blkCnt > 0u)
    {
      /* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
      /* Calculate dot product and then store the results in a temporary buffer. */
      sum += (q63_t) ((q31_t) * pSrcA++ * *pSrcB++);
  
      /* Decrement the loop counter */
      blkCnt--;
    }
  #endif
  
    /* Store the result in the destination buffer in 34.30 format */
    *result = sum;
  
  }
  
  /**    
   * @} end of dot_prod group    
   */
  