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_offset_q15.c    
  *    
  * Description:	Q15 vector offset.    
  *    
  * 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 offset    
   * @{    
   */
  
  /**    
   * @brief  Adds a constant offset to a Q15 vector.    
   * @param[in]  *pSrc points to the input vector    
   * @param[in]  offset is the offset to be added    
   * @param[out]  *pDst points to the output vector    
   * @param[in]  blockSize number of samples in the vector    
   * @return none.    
   *    
   * <b>Scaling and Overflow Behavior:</b>    
   * \par    
   * The function uses saturating arithmetic.    
   * Results outside of the allowable Q15 range [0x8000 0x7FFF] are saturated.    
   */
  
  void riscv_offset_q15(
    q15_t * pSrc,
    q15_t offset,
    q15_t * pDst,
    uint32_t blockSize)
  {
    uint32_t blkCnt;                               /* loop counter */
  
  #if defined (USE_DSP_RISCV)
    q31_t inA1, inA2, inB1, inB2;
  
    /*loop Unrolling */
    blkCnt = blockSize >> 1u;
    while (blkCnt > 0u)
    {
      /* C = A + B */
      /*read 2 elements from source buffer*/
      inA1 = *pSrc++;
      inA2 = *pSrc++;
      /*add the 2 elements to the offset value then saturate*/
      *pDst++ =(q15_t)clip((inA1 + offset),-32768,32767);
      *pDst++ =(q15_t)clip((inA2 + offset),-32768,32767);
      /* Decrement the loop counter */
      blkCnt--;
    }
  
    blkCnt = blockSize % 0x2u;
  
    while (blkCnt > 0u)
    {
      /* C = A + B */
      /* Add and then store the results in the destination buffer. */
      *pDst++ = (q15_t)clip((*pSrc++ + offset),-32768,32767);
      /* Decrement the loop counter */
      blkCnt--;
    }
  
  #else
  
    /* Initialize blkCnt with number of samples */
    blkCnt = blockSize;
  
    while(blkCnt > 0u)
    {
      /* C = A + offset */
      /* Add offset and then store the results in the destination buffer. */
      *pDst++ = (q15_t) __SSAT(((q31_t) * pSrc++ + offset), 16);
      /* Decrement the loop counter */
      blkCnt--;
    }
  #endif
  }
  
  /**    
   * @} end of offset group    
   */
  