text: /* ----------------------------------------------------------------------    
  * Copyright (C) 2010-2013 ARM Limited. All rights reserved.    
  *    
  * $Date:        17. January 2013
  * $Revision: 	V1.4.1  
  *    
  * Project: 	    CMSIS DSP Library    
  * Title:		arm_max_q31.c    
  *    
  * Description:	Maximum value of a Q31 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
  * 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 groupStats    
   */
  
  /**    
   * @addtogroup Max    
   * @{    
   */
  
  
  /**    
   * @brief Maximum value of a Q31 vector.    
   * @param[in]       *pSrc points to the input vector    
   * @param[in]       blockSize length of the input vector    
   * @param[out]      *pResult maximum value returned here    
   * @param[out]      *pIndex index of maximum value returned here    
   * @return none.    
   */
  
  void arm_max_q31(
    q31_t * pSrc,
    uint32_t blockSize,
    q31_t * pResult,
    uint32_t * pIndex)
  {
  #ifndef ARM_MATH_CM0_FAMILY
  
    /* Run the below code for Cortex-M4 and Cortex-M3 */
    q31_t maxVal1, maxVal2, out;                   /* Temporary variables to store the output value. */
    uint32_t blkCnt, outIndex, count;              /* loop counter */
  
    /* Initialise the count value. */
    count = 0u;
    /* Initialise the index value to zero. */
    outIndex = 0u;
    /* Load first input value that act as reference value for comparision */
    out = *pSrc++;
  
    /* Loop unrolling */
    blkCnt = (blockSize - 1u) >> 2u;
  
    /* Run the below code for Cortex-M4 and Cortex-M3 */
    while(blkCnt > 0u)
    {
      /* Initialize maxVal to the next consecutive values one by one */
      maxVal1 = *pSrc++;
  
      maxVal2 = *pSrc++;
  
      /* compare for the maximum value */
      if(out < maxVal1)
      {
        /* Update the maximum value and its index */
        out = maxVal1;
        outIndex = count + 1u;
      }
  
      maxVal1 = *pSrc++;
  
      /* compare for the maximum value */
      if(out < maxVal2)
      {
        /* Update the maximum value and its index */
        out = maxVal2;
        outIndex = count + 2u;
      }
  
      maxVal2 = *pSrc++;
  
      /* compare for the maximum value */
      if(out < maxVal1)
      {
        /* Update the maximum value and its index */
        out = maxVal1;
        outIndex = count + 3u;
      }
  
      /* compare for the maximum value */
      if(out < maxVal2)
      {
        /* Update the maximum value and its index */
        out = maxVal2;
        outIndex = count + 4u;
      }
  
      count += 4u;
  
      /* Decrement the loop counter */
      blkCnt--;
    }
  
    /* if (blockSize - 1u) is not multiple of 4 */
    blkCnt = (blockSize - 1u) % 4u;
  
  #else
  
    /* Run the below code for Cortex-M0 */
    q31_t maxVal1, out;                            /* Temporary variables to store the output value. */
    uint32_t blkCnt, outIndex;                     /* loop counter */
  
    /* Initialise the index value to zero. */
    outIndex = 0u;
    /* Load first input value that act as reference value for comparision */
    out = *pSrc++;
  
    blkCnt = (blockSize - 1u);
  
  #endif /* #ifndef ARM_MATH_CM0_FAMILY */
  
    while(blkCnt > 0u)
    {
      /* Initialize maxVal to the next consecutive values one by one */
      maxVal1 = *pSrc++;
  
      /* compare for the maximum value */
      if(out < maxVal1)
      {
        /* Update the maximum value and it's index */
        out = maxVal1;
        outIndex = blockSize - blkCnt;
      }
  
      /* Decrement the loop counter */
      blkCnt--;
  
    }
  
    /* Store the maximum value and its index into destination pointers */
    *pResult = out;
    *pIndex = outIndex;
  }
  
  /**    
   * @} end of Max group    
   */
  