k60-keil

K60-Keil版本（下载安装MDK4.23）

        acc2 += x2 * c0;

        /* acc3 +=  x[3] * y[srcBLen - 1] */
        acc3 += x3 * c0;

        /* Read y[srcBLen - 2] sample */
        c0 = *(py--);

        /* Read x[4] sample */
        x0 = *(px++);

        /* Perform the multiply-accumulate */
        /* acc0 +=  x[1] * y[srcBLen - 2] */
        acc0 += x1 * c0;
        /* acc1 +=  x[2] * y[srcBLen - 2] */
        acc1 += x2 * c0;
        /* acc2 +=  x[3] * y[srcBLen - 2] */
        acc2 += x3 * c0;
        /* acc3 +=  x[4] * y[srcBLen - 2] */
        acc3 += x0 * c0;

        /* Read y[srcBLen - 3] sample */
        c0 = *(py--);

        /* Read x[5] sample */
        x1 = *(px++);

        /* Perform the multiply-accumulates */
        /* acc0 +=  x[2] * y[srcBLen - 3] */
        acc0 += x2 * c0;
        /* acc1 +=  x[3] * y[srcBLen - 2] */
        acc1 += x3 * c0;
        /* acc2 +=  x[4] * y[srcBLen - 2] */
        acc2 += x0 * c0;
        /* acc3 +=  x[5] * y[srcBLen - 2] */
        acc3 += x1 * c0;

        /* Read y[srcBLen - 4] sample */
        c0 = *(py--);

        /* Read x[6] sample */
        x2 = *(px++);

        /* Perform the multiply-accumulates */
        /* acc0 +=  x[3] * y[srcBLen - 4] */
        acc0 += x3 * c0;
        /* acc1 +=  x[4] * y[srcBLen - 4] */
        acc1 += x0 * c0;
        /* acc2 +=  x[5] * y[srcBLen - 4] */
        acc2 += x1 * c0;
        /* acc3 +=  x[6] * y[srcBLen - 4] */
        acc3 += x2 * c0;


      } while(--k);

      /* If the srcBLen is not a multiple of 4, compute any remaining MACs here.   
       ** No loop unrolling is used. */
      k = srcBLen % 0x4u;

      while(k > 0u)
      {
        /* Read y[srcBLen - 5] sample */
        c0 = *(py--);

        /* Read x[7] sample */
        x3 = *(px++);

        /* Perform the multiply-accumulates */
        /* acc0 +=  x[4] * y[srcBLen - 5] */
        acc0 += x0 * c0;
        /* acc1 +=  x[5] * y[srcBLen - 5] */
        acc1 += x1 * c0;
        /* acc2 +=  x[6] * y[srcBLen - 5] */
        acc2 += x2 * c0;
        /* acc3 +=  x[7] * y[srcBLen - 5] */
        acc3 += x3 * c0;

        /* Reuse the present samples for the next MAC */
        x0 = x1;
        x1 = x2;
        x2 = x3;

        /* Decrement the loop counter */
        k--;
      }

      /* Store the result in the accumulator in the destination buffer. */
      *pOut++ = acc0;
      *pOut++ = acc1;
      *pOut++ = acc2;
      *pOut++ = acc3;

      /* Update the inputA and inputB pointers for next MAC calculation */
      px = pIn1 + (count * 4u);
      py = pSrc2;

      /* Increment the pointer pIn1 index, count by 1 */
      count++;

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

    /* If the blockSize2 is not a multiple of 4, compute any remaining output samples here.   
     ** No loop unrolling is used. */
    blkCnt = blockSize2 % 0x4u;

    while(blkCnt > 0u)
    {
      /* Accumulator is made zero for every iteration */
      sum = 0.0f;

      /* Apply loop unrolling and compute 4 MACs simultaneously. */
      k = srcBLen >> 2u;

      /* First part of the processing with loop unrolling.  Compute 4 MACs at a time.   
       ** a second loop below computes MACs for the remaining 1 to 3 samples. */
      while(k > 0u)
      {
        /* Perform the multiply-accumulates */
        sum += *px++ * *py--;
        sum += *px++ * *py--;
        sum += *px++ * *py--;
        sum += *px++ * *py--;

        /* Decrement the loop counter */
        k--;
      }

      /* If the srcBLen is not a multiple of 4, compute any remaining MACs here.   
       ** No loop unrolling is used. */
      k = srcBLen % 0x4u;

      while(k > 0u)
      {
        /* Perform the multiply-accumulate */
        sum += *px++ * *py--;

        /* Decrement the loop counter */
        k--;
      }

      /* Store the result in the accumulator in the destination buffer. */
      *pOut++ = sum;

      /* Update the inputA and inputB pointers for next MAC calculation */
      px = pIn1 + count;
      py = pSrc2;

      /* Increment the MAC count */
      count++;

      /* Decrement the loop counter */
      blkCnt--;
    }
  }
  else
  {
    /* If the srcBLen is not a multiple of 4,   
     * the blockSize2 loop cannot be unrolled by 4 */
    blkCnt = blockSize2;

    while(blkCnt > 0u)
    {
      /* Accumulator is made zero for every iteration */
      sum = 0.0f;

      /* srcBLen number of MACS should be performed */
      k = srcBLen;

      while(k > 0u)
      {
        /* Perform the multiply-accumulate */
        sum += *px++ * *py--;

        /* Decrement the loop counter */
        k--;
      }

      /* Store the result in the accumulator in the destination buffer. */
      *pOut++ = sum;

      /* Update the inputA and inputB pointers for next MAC calculation */
      px = pIn1 + count;
      py = pSrc2;

      /* Increment the MAC count */
      count++;

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


  /* --------------------------   
   * Initializations of stage3   
   * -------------------------*/

  /* sum += x[srcALen-srcBLen+1] * y[srcBLen-1] + x[srcALen-srcBLen+2] * y[srcBLen-2] +...+ x[srcALen-1] * y[1]   
   * sum += x[srcALen-srcBLen+2] * y[srcBLen-1] + x[srcALen-srcBLen+3] * y[srcBLen-2] +...+ x[srcALen-1] * y[2]   
   * ....   
   * sum +=  x[srcALen-2] * y[srcBLen-1] + x[srcALen-1] * y[srcBLen-2]   
   * sum +=  x[srcALen-1] * y[srcBLen-1]   
   */

  /* In this stage the MAC operations are decreased by 1 for every iteration.   
     The blockSize3 variable holds the number of MAC operations performed */

  /* Working pointer of inputA */
  pSrc1 = (pIn1 + srcALen) - (srcBLen - 1u);
  px = pSrc1;

  /* Working pointer of inputB */
  pSrc2 = pIn2 + (srcBLen - 1u);
  py = pSrc2;

  /* -------------------   
   * Stage3 process   
   * ------------------*/

  while(blockSize3 > 0u)
  {
    /* Accumulator is made zero for every iteration */
    sum = 0.0f;

    /* Apply loop unrolling and compute 4 MACs simultaneously. */
    k = blockSize3 >> 2u;

    /* First part of the processing with loop unrolling.  Compute 4 MACs at a time.   
     ** a second loop below computes MACs for the remaining 1 to 3 samples. */
    while(k > 0u)
    {
      /* sum += x[srcALen - srcBLen + 1] * y[srcBLen - 1] */
      sum += *px++ * *py--;

      /* sum += x[srcALen - srcBLen + 2] * y[srcBLen - 2] */
      sum += *px++ * *py--;

      /* sum += x[srcALen - srcBLen + 3] * y[srcBLen - 3] */
      sum += *px++ * *py--;

      /* sum += x[srcALen - srcBLen + 4] * y[srcBLen - 4] */
      sum += *px++ * *py--;

      /* Decrement the loop counter */
      k--;
    }

    /* If the blockSize3 is not a multiple of 4, compute any remaining MACs here.   
     ** No loop unrolling is used. */
    k = blockSize3 % 0x4u;

    while(k > 0u)
    {
      /* Perform the multiply-accumulates */
      /* sum +=  x[srcALen-1] * y[srcBLen-1] */
      sum += *px++ * *py--;

      /* Decrement the loop counter */
      k--;
    }

    /* Store the result in the accumulator in the destination buffer. */
    *pOut++ = sum;

    /* Update the inputA and inputB pointers for next MAC calculation */
    px = ++pSrc1;
    py = pSrc2;

    /* Decrement the loop counter */
    blockSize3--;
  }

#else

  /* Run the below code for Cortex-M0 */

  float32_t *pIn1 = pSrcA;                       /* inputA pointer */
  float32_t *pIn2 = pSrcB;                       /* inputB pointer */
  float32_t sum;                                 /* Accumulator */
  uint32_t i, j;                                 /* loop counters */

  /* Loop to calculate convolution for output length number of times */
  for (i = 0u; i < ((srcALen + srcBLen) - 1u); i++)
  {
    /* Initialize sum with zero to carry out MAC operations */
    sum = 0.0f;

    /* Loop to perform MAC operations according to convolution equation */
    for (j = 0u; j <= i; j++)
    {
      /* Check the array limitations */
      if((((i - j) < srcBLen) && (j < srcALen)))
      {
        /* z[i] += x[i-j] * y[j] */
        sum += pIn1[j] * pIn2[i - j];
      }
    }
    /* Store the output in the destination buffer */
    pDst[i] = sum;
  }

#endif /*   #ifndef ARM_MATH_CM0        */

}

/**   
 * @} end of Conv group   
 */