text: /* ----------------------------------------------------------------------
   * Project:      CMSIS DSP Library
   * Title:        arm_conv_partial_opt_q7.c
   * Description:  Partial convolution of Q7 sequences
   *
   * $Date:        27. January 2017
   * $Revision:    V.1.5.1
   *
   * Target Processor: Cortex-M cores
   * -------------------------------------------------------------------- */
  /*
   * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
   *
   * SPDX-License-Identifier: Apache-2.0
   *
   * Licensed under the Apache License, Version 2.0 (the License); you may
   * not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an AS IS BASIS, WITHOUT
   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include "arm_math.h"
  
  /**
   * @ingroup groupFilters
   */
  
  /**
   * @addtogroup PartialConv
   * @{
   */
  
  /**
   * @brief Partial convolution of Q7 sequences.
   * @param[in]       *pSrcA points to the first input sequence.
   * @param[in]       srcALen length of the first input sequence.
   * @param[in]       *pSrcB points to the second input sequence.
   * @param[in]       srcBLen length of the second input sequence.
   * @param[out]      *pDst points to the location where the output result is written.
   * @param[in]       firstIndex is the first output sample to start with.
   * @param[in]       numPoints is the number of output points to be computed.
   * @param[in]      *pScratch1 points to scratch buffer(of type q15_t) of size max(srcALen, srcBLen) + 2*min(srcALen, srcBLen) - 2.
   * @param[in]      *pScratch2 points to scratch buffer (of type q15_t) of size min(srcALen, srcBLen).
   * @return  Returns either ARM_MATH_SUCCESS if the function completed correctly or ARM_MATH_ARGUMENT_ERROR if the requested subset is not in the range [0 srcALen+srcBLen-2].
   *
   * \par Restrictions
   *  If the silicon does not support unaligned memory access enable the macro UNALIGNED_SUPPORT_DISABLE
   *	In this case input, output, scratch1 and scratch2 buffers should be aligned by 32-bit
   *
   *
   *
   */
  
  
  #ifndef UNALIGNED_SUPPORT_DISABLE
  
  arm_status arm_conv_partial_opt_q7(
    q7_t * pSrcA,
    uint32_t srcALen,
    q7_t * pSrcB,
    uint32_t srcBLen,
    q7_t * pDst,
    uint32_t firstIndex,
    uint32_t numPoints,
    q15_t * pScratch1,
    q15_t * pScratch2)
  {
  
    q15_t *pScr2, *pScr1;                          /* Intermediate pointers for scratch pointers */
    q15_t x4;                                      /* Temporary input variable */
    q7_t *pIn1, *pIn2;                             /* inputA and inputB pointer */
    uint32_t j, k, blkCnt, tapCnt;                 /* loop counter */
    q7_t *px;                                      /* Temporary input1 pointer */
    q15_t *py;                                     /* Temporary input2 pointer */
    q31_t acc0, acc1, acc2, acc3;                  /* Accumulator */
    q31_t x1, x2, x3, y1;                          /* Temporary input variables */
    arm_status status;
    q7_t *pOut = pDst;                             /* output pointer */
    q7_t out0, out1, out2, out3;                   /* temporary variables */
  
    /* Check for range of output samples to be calculated */
    if ((firstIndex + numPoints) > ((srcALen + (srcBLen - 1U))))
    {
      /* Set status as ARM_MATH_ARGUMENT_ERROR */
      status = ARM_MATH_ARGUMENT_ERROR;
    }
    else
    {
  
      /* The algorithm implementation is based on the lengths of the inputs. */
      /* srcB is always made to slide across srcA. */
      /* So srcBLen is always considered as shorter or equal to srcALen */
      if (srcALen >= srcBLen)
      {
        /* Initialization of inputA pointer */
        pIn1 = pSrcA;
  
        /* Initialization of inputB pointer */
        pIn2 = pSrcB;
      }
      else
      {
        /* Initialization of inputA pointer */
        pIn1 = pSrcB;
  
        /* Initialization of inputB pointer */
        pIn2 = pSrcA;
  
        /* srcBLen is always considered as shorter or equal to srcALen */
        j = srcBLen;
        srcBLen = srcALen;
        srcALen = j;
      }
  
      /* pointer to take end of scratch2 buffer */
      pScr2 = pScratch2;
  
      /* points to smaller length sequence */
      px = pIn2 + srcBLen - 1;
  
      /* Apply loop unrolling and do 4 Copies simultaneously. */
      k = srcBLen >> 2U;
  
      /* First part of the processing with loop unrolling copies 4 data points at a time.
       ** a second loop below copies for the remaining 1 to 3 samples. */
      while (k > 0U)
      {
        /* copy second buffer in reversal manner */
        x4 = (q15_t) * px--;
        *pScr2++ = x4;
        x4 = (q15_t) * px--;
        *pScr2++ = x4;
        x4 = (q15_t) * px--;
        *pScr2++ = x4;
        x4 = (q15_t) * px--;
        *pScr2++ = x4;
  
        /* Decrement the loop counter */
        k--;
      }
  
      /* If the count is not a multiple of 4, copy remaining samples here.
       ** No loop unrolling is used. */
      k = srcBLen % 0x4U;
  
      while (k > 0U)
      {
        /* copy second buffer in reversal manner for remaining samples */
        x4 = (q15_t) * px--;
        *pScr2++ = x4;
  
        /* Decrement the loop counter */
        k--;
      }
  
      /* Initialze temporary scratch pointer */
      pScr1 = pScratch1;
  
      /* Fill (srcBLen - 1U) zeros in scratch buffer */
      arm_fill_q15(0, pScr1, (srcBLen - 1U));
  
      /* Update temporary scratch pointer */
      pScr1 += (srcBLen - 1U);
  
      /* Copy (srcALen) samples in scratch buffer */
      /* Apply loop unrolling and do 4 Copies simultaneously. */
      k = srcALen >> 2U;
  
      /* First part of the processing with loop unrolling copies 4 data points at a time.
       ** a second loop below copies for the remaining 1 to 3 samples. */
      while (k > 0U)
      {
        /* copy second buffer in reversal manner */
        x4 = (q15_t) * pIn1++;
        *pScr1++ = x4;
        x4 = (q15_t) * pIn1++;
        *pScr1++ = x4;
        x4 = (q15_t) * pIn1++;
        *pScr1++ = x4;
        x4 = (q15_t) * pIn1++;
        *pScr1++ = x4;
  
        /* Decrement the loop counter */
        k--;
      }
  
      /* If the count is not a multiple of 4, copy remaining samples here.
       ** No loop unrolling is used. */
      k = srcALen % 0x4U;
  
      while (k > 0U)
      {
        /* copy second buffer in reversal manner for remaining samples */
        x4 = (q15_t) * pIn1++;
        *pScr1++ = x4;
  
        /* Decrement the loop counter */
        k--;
      }
  
      /* Fill (srcBLen - 1U) zeros at end of scratch buffer */
      arm_fill_q15(0, pScr1, (srcBLen - 1U));
  
      /* Update pointer */
      pScr1 += (srcBLen - 1U);
  
  
      /* Temporary pointer for scratch2 */
      py = pScratch2;
  
      /* Initialization of pIn2 pointer */
      pIn2 = (q7_t *) py;
  
      pScr2 = py;
  
      pOut = pDst + firstIndex;
  
      pScratch1 += firstIndex;
  
      /* Actual convolution process starts here */
      blkCnt = (numPoints) >> 2;
  
  
      while (blkCnt > 0)
      {
        /* Initialze temporary scratch pointer as scratch1 */
        pScr1 = pScratch1;
  
        /* Clear Accumlators */
        acc0 = 0;
        acc1 = 0;
        acc2 = 0;
        acc3 = 0;
  
        /* Read two samples from scratch1 buffer */
        x1 = *__SIMD32(pScr1)++;
  
        /* Read next two samples from scratch1 buffer */
        x2 = *__SIMD32(pScr1)++;
  
        tapCnt = (srcBLen) >> 2U;
  
        while (tapCnt > 0U)
        {
  
          /* Read four samples from smaller buffer */
          y1 = _SIMD32_OFFSET(pScr2);
  
          /* multiply and accumlate */
          acc0 = __SMLAD(x1, y1, acc0);
          acc2 = __SMLAD(x2, y1, acc2);
  
          /* pack input data */
  #ifndef ARM_MATH_BIG_ENDIAN
          x3 = __PKHBT(x2, x1, 0);
  #else
          x3 = __PKHBT(x1, x2, 0);
  #endif
  
          /* multiply and accumlate */
          acc1 = __SMLADX(x3, y1, acc1);
  
          /* Read next two samples from scratch1 buffer */
          x1 = *__SIMD32(pScr1)++;
  
          /* pack input data */
  #ifndef ARM_MATH_BIG_ENDIAN
          x3 = __PKHBT(x1, x2, 0);
  #else
          x3 = __PKHBT(x2, x1, 0);
  #endif
  
          acc3 = __SMLADX(x3, y1, acc3);
  
          /* Read four samples from smaller buffer */
          y1 = _SIMD32_OFFSET(pScr2 + 2U);
  
          acc0 = __SMLAD(x2, y1, acc0);
  
          acc2 = __SMLAD(x1, y1, acc2);
  
          acc1 = __SMLADX(x3, y1, acc1);
  
          x2 = *__SIMD32(pScr1)++;
  
  #ifndef ARM_MATH_BIG_ENDIAN
          x3 = __PKHBT(x2, x1, 0);
  #else
          x3 = __PKHBT(x1, x2, 0);
  #endif
  
          acc3 = __SMLADX(x3, y1, acc3);
  
          pScr2 += 4U;
  
  
          /* Decrement the loop counter */
          tapCnt--;
        }
  
  
  
        /* Update scratch pointer for remaining samples of smaller length sequence */
        pScr1 -= 4U;
  
  
        /* apply same above for remaining samples of smaller length sequence */
        tapCnt = (srcBLen) & 3U;
  
        while (tapCnt > 0U)
        {
  
          /* accumlate the results */
          acc0 += (*pScr1++ * *pScr2);
          acc1 += (*pScr1++ * *pScr2);
          acc2 += (*pScr1++ * *pScr2);
          acc3 += (*pScr1++ * *pScr2++);
  
          pScr1 -= 3U;
  
          /* Decrement the loop counter */
          tapCnt--;
        }
  
        blkCnt--;
  
        /* Store the result in the accumulator in the destination buffer. */
        out0 = (q7_t) (__SSAT(acc0 >> 7U, 8));
        out1 = (q7_t) (__SSAT(acc1 >> 7U, 8));
        out2 = (q7_t) (__SSAT(acc2 >> 7U, 8));
        out3 = (q7_t) (__SSAT(acc3 >> 7U, 8));
  
        *__SIMD32(pOut)++ = __PACKq7(out0, out1, out2, out3);
  
        /* Initialization of inputB pointer */
        pScr2 = py;
  
        pScratch1 += 4U;
  
      }
  
      blkCnt = (numPoints) & 0x3;
  
      /* Calculate convolution for remaining samples of Bigger length sequence */
      while (blkCnt > 0)
      {
        /* Initialze temporary scratch pointer as scratch1 */
        pScr1 = pScratch1;
  
        /* Clear Accumlators */
        acc0 = 0;
  
        tapCnt = (srcBLen) >> 1U;
  
        while (tapCnt > 0U)
        {
  
          /* Read next two samples from scratch1 buffer */
          x1 = *__SIMD32(pScr1)++;
  
          /* Read two samples from smaller buffer */
          y1 = *__SIMD32(pScr2)++;
  
          acc0 = __SMLAD(x1, y1, acc0);
  
          /* Decrement the loop counter */
          tapCnt--;
        }
  
        tapCnt = (srcBLen) & 1U;
  
        /* apply same above for remaining samples of smaller length sequence */
        while (tapCnt > 0U)
        {
  
          /* accumlate the results */
          acc0 += (*pScr1++ * *pScr2++);
  
          /* Decrement the loop counter */
          tapCnt--;
        }
  
        blkCnt--;
  
        /* Store the result in the accumulator in the destination buffer. */
        *pOut++ = (q7_t) (__SSAT(acc0 >> 7U, 8));
  
        /* Initialization of inputB pointer */
        pScr2 = py;
  
        pScratch1 += 1U;
  
      }
  
      /* set status as ARM_MATH_SUCCESS */
      status = ARM_MATH_SUCCESS;
  
  
    }
  
    return (status);
  
  }
  
  #else
  
  arm_status arm_conv_partial_opt_q7(
    q7_t * pSrcA,
    uint32_t srcALen,
    q7_t * pSrcB,
    uint32_t srcBLen,
    q7_t * pDst,
    uint32_t firstIndex,
    uint32_t numPoints,
    q15_t * pScratch1,
    q15_t * pScratch2)
  {
  
    q15_t *pScr2, *pScr1;                          /* Intermediate pointers for scratch pointers */
    q15_t x4;                                      /* Temporary input variable */
    q7_t *pIn1, *pIn2;                             /* inputA and inputB pointer */
    uint32_t j, k, blkCnt, tapCnt;                 /* loop counter */
    q7_t *px;                                      /* Temporary input1 pointer */
    q15_t *py;                                     /* Temporary input2 pointer */
    q31_t acc0, acc1, acc2, acc3;                  /* Accumulator */
    arm_status status;
    q7_t *pOut = pDst;                             /* output pointer */
    q15_t x10, x11, x20, x21;                      /* Temporary input variables */
    q15_t y10, y11;                                /* Temporary input variables */
  
    /* Check for range of output samples to be calculated */
    if ((firstIndex + numPoints) > ((srcALen + (srcBLen - 1U))))
    {
      /* Set status as ARM_MATH_ARGUMENT_ERROR */
      status = ARM_MATH_ARGUMENT_ERROR;
    }
    else
    {
  
      /* The algorithm implementation is based on the lengths of the inputs. */
      /* srcB is always made to slide across srcA. */
      /* So srcBLen is always considered as shorter or equal to srcALen */
      if (srcALen >= srcBLen)
      {
        /* Initialization of inputA pointer */
        pIn1 = pSrcA;
  
        /* Initialization of inputB pointer */
        pIn2 = pSrcB;
      }
      else
      {
        /* Initialization of inputA pointer */
        pIn1 = pSrcB;
  
        /* Initialization of inputB pointer */
        pIn2 = pSrcA;
  
        /* srcBLen is always considered as shorter or equal to srcALen */
        j = srcBLen;
        srcBLen = srcALen;
        srcALen = j;
      }
  
      /* pointer to take end of scratch2 buffer */
      pScr2 = pScratch2;
  
      /* points to smaller length sequence */
      px = pIn2 + srcBLen - 1;
  
      /* Apply loop unrolling and do 4 Copies simultaneously. */
      k = srcBLen >> 2U;
  
      /* First part of the processing with loop unrolling copies 4 data points at a time.
       ** a second loop below copies for the remaining 1 to 3 samples. */
      while (k > 0U)
      {
        /* copy second buffer in reversal manner */
        x4 = (q15_t) * px--;
        *pScr2++ = x4;
        x4 = (q15_t) * px--;
        *pScr2++ = x4;
        x4 = (q15_t) * px--;
        *pScr2++ = x4;
        x4 = (q15_t) * px--;
        *pScr2++ = x4;
  
        /* Decrement the loop counter */
        k--;
      }
  
      /* If the count is not a multiple of 4, copy remaining samples here.
       ** No loop unrolling is used. */
      k = srcBLen % 0x4U;
  
      while (k > 0U)
      {
        /* copy second buffer in reversal manner for remaining samples */
        x4 = (q15_t) * px--;
        *pScr2++ = x4;
  
        /* Decrement the loop counter */
        k--;
      }
  
      /* Initialze temporary scratch pointer */
      pScr1 = pScratch1;
  
      /* Fill (srcBLen - 1U) zeros in scratch buffer */
      arm_fill_q15(0, pScr1, (srcBLen - 1U));
  
      /* Update temporary scratch pointer */
      pScr1 += (srcBLen - 1U);
  
      /* Copy (srcALen) samples in scratch buffer */
      /* Apply loop unrolling and do 4 Copies simultaneously. */
      k = srcALen >> 2U;
  
      /* First part of the processing with loop unrolling copies 4 data points at a time.
       ** a second loop below copies for the remaining 1 to 3 samples. */
      while (k > 0U)
      {
        /* copy second buffer in reversal manner */
        x4 = (q15_t) * pIn1++;
        *pScr1++ = x4;
        x4 = (q15_t) * pIn1++;
        *pScr1++ = x4;
        x4 = (q15_t) * pIn1++;
        *pScr1++ = x4;
        x4 = (q15_t) * pIn1++;
        *pScr1++ = x4;
  
        /* Decrement the loop counter */
        k--;
      }
  
      /* If the count is not a multiple of 4, copy remaining samples here.
       ** No loop unrolling is used. */
      k = srcALen % 0x4U;
  
      while (k > 0U)
      {
        /* copy second buffer in reversal manner for remaining samples */
        x4 = (q15_t) * pIn1++;
        *pScr1++ = x4;
  
        /* Decrement the loop counter */
        k--;
      }
  
      /* Apply loop unrolling and do 4 Copies simultaneously. */
      k = (srcBLen - 1U) >> 2U;
  
      /* First part of the processing with loop unrolling copies 4 data points at a time.
       ** a second loop below copies for the remaining 1 to 3 samples. */
      while (k > 0U)
      {
        /* copy second buffer in reversal manner */
        *pScr1++ = 0;
        *pScr1++ = 0;
        *pScr1++ = 0;
        *pScr1++ = 0;
  
        /* Decrement the loop counter */
        k--;
      }
  
      /* If the count is not a multiple of 4, copy remaining samples here.
       ** No loop unrolling is used. */
      k = (srcBLen - 1U) % 0x4U;
  
      while (k > 0U)
      {
        /* copy second buffer in reversal manner for remaining samples */
        *pScr1++ = 0;
  
        /* Decrement the loop counter */
        k--;
      }
  
  
      /* Temporary pointer for scratch2 */
      py = pScratch2;
  
      /* Initialization of pIn2 pointer */
      pIn2 = (q7_t *) py;
  
      pScr2 = py;
  
      pOut = pDst + firstIndex;
  
      pScratch1 += firstIndex;
  
      /* Actual convolution process starts here */
      blkCnt = (numPoints) >> 2;
  
  
      while (blkCnt > 0)
      {
        /* Initialze temporary scratch pointer as scratch1 */
        pScr1 = pScratch1;
  
        /* Clear Accumlators */
        acc0 = 0;
        acc1 = 0;
        acc2 = 0;
        acc3 = 0;
  
        /* Read two samples from scratch1 buffer */
        x10 = *pScr1++;
        x11 = *pScr1++;
  
        /* Read next two samples from scratch1 buffer */
        x20 = *pScr1++;
        x21 = *pScr1++;
  
        tapCnt = (srcBLen) >> 2U;
  
        while (tapCnt > 0U)
        {
  
          /* Read four samples from smaller buffer */
          y10 = *pScr2;
          y11 = *(pScr2 + 1U);
  
          /* multiply and accumlate */
          acc0 += (q31_t) x10 *y10;
          acc0 += (q31_t) x11 *y11;
          acc2 += (q31_t) x20 *y10;
          acc2 += (q31_t) x21 *y11;
  
  
          acc1 += (q31_t) x11 *y10;
          acc1 += (q31_t) x20 *y11;
  
          /* Read next two samples from scratch1 buffer */
          x10 = *pScr1;
          x11 = *(pScr1 + 1U);
  
          /* multiply and accumlate */
          acc3 += (q31_t) x21 *y10;
          acc3 += (q31_t) x10 *y11;
  
          /* Read next two samples from scratch2 buffer */
          y10 = *(pScr2 + 2U);
          y11 = *(pScr2 + 3U);
  
          /* multiply and accumlate */
          acc0 += (q31_t) x20 *y10;
          acc0 += (q31_t) x21 *y11;
          acc2 += (q31_t) x10 *y10;
          acc2 += (q31_t) x11 *y11;
          acc1 += (q31_t) x21 *y10;
          acc1 += (q31_t) x10 *y11;
  
          /* Read next two samples from scratch1 buffer */
          x20 = *(pScr1 + 2);
          x21 = *(pScr1 + 3);
  
          /* multiply and accumlate */
          acc3 += (q31_t) x11 *y10;
          acc3 += (q31_t) x20 *y11;
  
          /* update scratch pointers */
  
          pScr1 += 4U;
          pScr2 += 4U;
  
          /* Decrement the loop counter */
          tapCnt--;
        }
  
  
  
        /* Update scratch pointer for remaining samples of smaller length sequence */
        pScr1 -= 4U;
  
  
        /* apply same above for remaining samples of smaller length sequence */
        tapCnt = (srcBLen) & 3U;
  
        while (tapCnt > 0U)
        {
  
          /* accumlate the results */
          acc0 += (*pScr1++ * *pScr2);
          acc1 += (*pScr1++ * *pScr2);
          acc2 += (*pScr1++ * *pScr2);
          acc3 += (*pScr1++ * *pScr2++);
  
          pScr1 -= 3U;
  
          /* Decrement the loop counter */
          tapCnt--;
        }
  
        blkCnt--;
  
        /* Store the result in the accumulator in the destination buffer. */
        *pOut++ = (q7_t) (__SSAT(acc0 >> 7U, 8));
        *pOut++ = (q7_t) (__SSAT(acc1 >> 7U, 8));
        *pOut++ = (q7_t) (__SSAT(acc2 >> 7U, 8));
        *pOut++ = (q7_t) (__SSAT(acc3 >> 7U, 8));
  
        /* Initialization of inputB pointer */
        pScr2 = py;
  
        pScratch1 += 4U;
  
      }
  
      blkCnt = (numPoints) & 0x3;
  
      /* Calculate convolution for remaining samples of Bigger length sequence */
      while (blkCnt > 0)
      {
        /* Initialze temporary scratch pointer as scratch1 */
        pScr1 = pScratch1;
  
        /* Clear Accumlators */
        acc0 = 0;
  
        tapCnt = (srcBLen) >> 1U;
  
        while (tapCnt > 0U)
        {
  
          /* Read next two samples from scratch1 buffer */
          x10 = *pScr1++;
          x11 = *pScr1++;
  
          /* Read two samples from smaller buffer */
          y10 = *pScr2++;
          y11 = *pScr2++;
  
          /* multiply and accumlate */
          acc0 += (q31_t) x10 *y10;
          acc0 += (q31_t) x11 *y11;
  
          /* Decrement the loop counter */
          tapCnt--;
        }
  
        tapCnt = (srcBLen) & 1U;
  
        /* apply same above for remaining samples of smaller length sequence */
        while (tapCnt > 0U)
        {
  
          /* accumlate the results */
          acc0 += (*pScr1++ * *pScr2++);
  
          /* Decrement the loop counter */
          tapCnt--;
        }
  
        blkCnt--;
  
        /* Store the result in the accumulator in the destination buffer. */
        *pOut++ = (q7_t) (__SSAT(acc0 >> 7U, 8));
  
        /* Initialization of inputB pointer */
        pScr2 = py;
  
        pScratch1 += 1U;
  
      }
  
      /* set status as ARM_MATH_SUCCESS */
      status = ARM_MATH_SUCCESS;
  
    }
  
    return (status);
  
  }
  
  #endif	/*	#ifndef UNALIGNED_SUPPORT_DISABLE	*/
  
  
  
  /**
   * @} end of PartialConv group
   */
  