text: /* ----------------------------------------------------------------------    
  * Copyright (C) 2010-2013 ARM Limited. All rights reserved.    
  *    
  * $Date:        17. January 2013 
  * $Revision: 	V1.4.1
  *    
  * Project: 	    CMSIS DSP Library    
  * Title:	    arm_mat_add_q15.c    
  *    
  * Description:	Q15 matrix addition    
  *    
  * 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.    
  * -------------------------------------------------------------------- */
  
  #include "arm_math.h"
  
  /**    
   * @ingroup groupMatrix    
   */
  
  /**    
   * @addtogroup MatrixAdd    
   * @{    
   */
  
  /**    
   * @brief Q15 matrix addition.    
   * @param[in]       *pSrcA points to the first input matrix structure    
   * @param[in]       *pSrcB points to the second input matrix structure    
   * @param[out]      *pDst points to output matrix structure    
   * @return     		The function returns either    
   * <code>ARM_MATH_SIZE_MISMATCH</code> or <code>ARM_MATH_SUCCESS</code> based on the outcome of size checking.    
   *    
   * <b>Scaling and Overflow Behavior:</b>    
   * \par    
   * The function uses saturating arithmetic.    
   * Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated.    
   */
  
  arm_status arm_mat_add_q15(
    const arm_matrix_instance_q15 * pSrcA,
    const arm_matrix_instance_q15 * pSrcB,
    arm_matrix_instance_q15 * pDst)
  {
    q15_t *pInA = pSrcA->pData;                    /* input data matrix pointer A  */
    q15_t *pInB = pSrcB->pData;                    /* input data matrix pointer B */
    q15_t *pOut = pDst->pData;                     /* output data matrix pointer */
    uint16_t numSamples;                           /* total number of elements in the matrix  */
    uint32_t blkCnt;                               /* loop counters  */
    arm_status status;                             /* status of matrix addition  */
  
  #ifdef ARM_MATH_MATRIX_CHECK
  
  
    /* Check for matrix mismatch condition */
    if((pSrcA->numRows != pSrcB->numRows) ||
       (pSrcA->numCols != pSrcB->numCols) ||
       (pSrcA->numRows != pDst->numRows) || (pSrcA->numCols != pDst->numCols))
    {
      /* Set status as ARM_MATH_SIZE_MISMATCH */
      status = ARM_MATH_SIZE_MISMATCH;
    }
    else
  #endif /*    #ifdef ARM_MATH_MATRIX_CHECK    */
  
    {
      /* Total number of samples in the input matrix */
      numSamples = (uint16_t) (pSrcA->numRows * pSrcA->numCols);
  
  #ifndef ARM_MATH_CM0_FAMILY
  
      /* Run the below code for Cortex-M4 and Cortex-M3 */
  
      /* Loop unrolling */
      blkCnt = (uint32_t) numSamples >> 2u;
  
      /* 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(m,n) = A(m,n) + B(m,n) */
        /* Add, Saturate and then store the results in the destination buffer. */
        *__SIMD32(pOut)++ = __QADD16(*__SIMD32(pInA)++, *__SIMD32(pInB)++);
        *__SIMD32(pOut)++ = __QADD16(*__SIMD32(pInA)++, *__SIMD32(pInB)++);
  
        /* 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 = (uint32_t) numSamples % 0x4u;
  
      /* q15 pointers of input and output are initialized */
  
      while(blkCnt > 0u)
      {
        /* C(m,n) = A(m,n) + B(m,n) */
        /* Add, Saturate and then store the results in the destination buffer. */
        *pOut++ = (q15_t) __QADD16(*pInA++, *pInB++);
  
        /* Decrement the loop counter */
        blkCnt--;
      }
  
  #else
  
      /* Run the below code for Cortex-M0 */
  
      /* Initialize blkCnt with number of samples */
      blkCnt = (uint32_t) numSamples;
  
  
      /* q15 pointers of input and output are initialized */
      while(blkCnt > 0u)
      {
        /* C(m,n) = A(m,n) + B(m,n) */
        /* Add, Saturate and then store the results in the destination buffer. */
        *pOut++ = (q15_t) __SSAT(((q31_t) * pInA++ + *pInB++), 16);
  
        /* Decrement the loop counter */
        blkCnt--;
      }
  
  #endif /* #ifndef ARM_MATH_CM0_FAMILY */
  
      /* set status as ARM_MATH_SUCCESS */
      status = ARM_MATH_SUCCESS;
    }
  
    /* Return to application */
    return (status);
  }
  
  /**    
   * @} end of MatrixAdd group    
   */
  