bl_mcu_sdk/examples/dsp/StatisticsFunctions_part1/absmax.c

#include "ref.h"

void ref_absmax_f32(
  const float32_t * pSrc,
        uint32_t blockSize,
        float32_t * pResult,
        uint32_t * pIndex)
{
        float32_t maxVal, out;                         /* Temporary variables to store the output value. */
        uint32_t blkCnt, outIndex;                     /* Loop counter */

  /* Initialise index value to zero. */
  outIndex = 0U;

  /* Load first input value that act as reference value for comparision */
  out = fabsf(*pSrc++);

  /* Initialize blkCnt with number of samples */
  blkCnt = (blockSize - 1U);


  while (blkCnt > 0U)
  {
    /* Initialize maxVal to the next consecutive values one by one */
    maxVal = fabsf(*pSrc++);

    /* compare for the maximum value */
    if (out < maxVal)
    {
      /* Update the maximum value and it's index */
      out = maxVal;
      outIndex = blockSize - blkCnt;
    }

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

  /* Store the maximum value and it's index into destination pointers */
  *pResult = out;
  *pIndex = outIndex;
}

void ref_absmax_q7(
  const q7_t * pSrc,
        uint32_t blockSize,
        q7_t * pResult,
        uint32_t * pIndex)
{
       q7_t maxVal, out;                              /* Temporary variables to store the output value. */
        uint32_t blkCnt, outIndex;                     /* Loop counter */


  /* Initialise index value to zero. */
  outIndex = 0U;
  /* Load first input value that act as reference value for comparision */
  out = (*pSrc > 0) ? *pSrc : ((*pSrc == (q7_t) 0x80) ? (q7_t) 0x7f : -*pSrc);
  pSrc++;

  /* Initialize blkCnt with number of samples */
  blkCnt = (blockSize - 1U);

  while (blkCnt > 0U)
  {
    /* Initialize maxVal to the next consecutive values one by one */
    maxVal = (*pSrc > 0) ? *pSrc : ((*pSrc == (q7_t) 0x80) ? (q7_t) 0x7f : -*pSrc);
    pSrc++;

    /* compare for the maximum value */
    if (out < maxVal)
    {
      /* Update the maximum value and it's index */
      out = maxVal;
      outIndex = blockSize - blkCnt;
    }

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

  /* Store the maximum value and it's index into destination pointers */
  *pResult = out;
  *pIndex = outIndex;
}

void ref_absmax_q15(
  const q15_t * pSrc,
        uint32_t blockSize,
        q15_t * pResult,
        uint32_t * pIndex)
{
       q15_t maxVal, out;                             /* Temporary variables to store the output value. */
        uint32_t blkCnt, outIndex;                     /* Loop counter */

  /* Initialise index value to zero. */
  outIndex = 0U;
  /* Load first input value that act as reference value for comparision */
  out = (*pSrc > 0) ? *pSrc : ((*pSrc == (q15_t) 0x8000) ? 0x7fff : -*pSrc);
  pSrc++;

  /* Initialize blkCnt with number of samples */
  blkCnt = (blockSize - 1U);

  while (blkCnt > 0U)
  {
    /* Initialize maxVal to the next consecutive values one by one */
    maxVal = (*pSrc > 0) ? *pSrc : ((*pSrc == (q15_t) 0x8000) ? 0x7fff : -*pSrc);
    pSrc++;

    /* compare for the maximum value */
    if (out < maxVal)
    {
      /* Update the maximum value and it's index */
      out = maxVal;
      outIndex = blockSize - blkCnt;
    }

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

  /* Store the maximum value and it's index into destination pointers */
  *pResult = out;
  *pIndex = outIndex;
}

void ref_absmax_q31(
  const q31_t * pSrc,
        uint32_t blockSize,
        q31_t * pResult,
        uint32_t * pIndex)
{
        q31_t maxVal, out;                             /* Temporary variables to store the output value. */
        uint32_t blkCnt, outIndex;                     /* Loop counter */


  /* Initialise index value to zero. */
  outIndex = 0U;
  /* Load first input value that act as reference value for comparision */
  out = (*pSrc > 0) ? *pSrc : ((*pSrc == INT32_MIN) ? INT32_MAX : -*pSrc);
  pSrc++;

  /* Initialize blkCnt with number of samples */
  blkCnt = (blockSize - 1U);

  while (blkCnt > 0U)
  {
    /* Initialize maxVal to the next consecutive values one by one */
    maxVal = (*pSrc > 0) ? *pSrc : ((*pSrc == INT32_MIN) ? INT32_MAX : -*pSrc);
    pSrc++;

    /* compare for the maximum value */
    if (out < maxVal)
    {
      /* Update the maximum value and it's index */
      out = maxVal;
      outIndex = blockSize - blkCnt;
    }

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

  /* Store the maximum value and it's index into destination pointers */
  *pResult = out;
  *pIndex = outIndex;
}