text: /*
   * Copyright (C) 2010-2020 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.
   */
  
  /* ----------------------------------------------------------------------
   * Project:      CMSIS NN Library
   * Title:        arm_q7_to_q15_reordered_no_shift.c
   * Description:  Converts the elements of the Q7 vector to reordered Q15 vector without left-shift
   *
   * $Date:        May 29, 2020
   * $Revision:    V.1.0.1
   *
   * Target Processor:  Cortex-M cores
   *
   * -------------------------------------------------------------------- */
  
  #include "edge-impulse-sdk/CMSIS/NN/Include/arm_nnsupportfunctions.h"
  
  /**
   * @ingroup groupSupport
   */
  
  /**
   * @addtogroup nndata_convert
   * @{
   */
  
  /**
   * @brief Converts the elements of the Q7 vector to reordered Q15 vector without left-shift
   * @param[in]       *pSrc points to the Q7 input vector
   * @param[out]      *pDst points to the Q15 output vector
   * @param[in]       blockSize length of the input vector
   *
   * @details
   *
   * This function does the q7 to q15 expansion with re-ordering
   *
   * <pre>
   *                          |   A1   |   A2   |   A3   |   A4   |
   *
   *                           0      7 8     15 16    23 24    31
   * </pre>
   *
   * is converted into:
   *
   * <pre>
   *  |       A1       |       A3       |   and  |       A2       |       A4       |
   *
   *   0             15 16            31          0             15 16            31
   * </pre>
   *
   *
   * This looks strange but is natural considering how sign-extension is done at
   * assembly level.
   *
   * The expansion of other other oprand will follow the same rule so that the end
   * results are the same.
   *
   * The tail (i.e., last (N % 4) elements) will still be in original order.
   *
   */
  
  void arm_q7_to_q15_reordered_no_shift(const q7_t *pSrc, q15_t *pDst, uint32_t blockSize)
  {
      const q7_t *pIn = pSrc; /* Src pointer */
      uint32_t blkCnt;        /* loop counter */
  
  #ifndef ARM_MATH_CM0_FAMILY
      q31_t in;
      q31_t in1, in2;
  
      /* Run the below code for Cortex-M4 and Cortex-M3 */
  
      /*loop Unrolling */
      blkCnt = blockSize >> 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 = (q15_t) A << 8 */
          /* convert from q7 to q15 and then store the results in the destination buffer */
          in = arm_nn_read_q7x4_ia(&pIn);
  
          /* rotatate in by 8 and extend two q7_t values to q15_t values */
          in1 = __SXTB16(__ROR((uint32_t)in, 8));
  
          /* extend remainig two q7_t values to q15_t values */
          in2 = __SXTB16(in);
  
  #ifndef ARM_MATH_BIG_ENDIAN
          *__SIMD32(pDst)++ = in2;
          *__SIMD32(pDst)++ = in1;
  #else
          *__SIMD32(pDst)++ = in1;
          *__SIMD32(pDst)++ = in2;
  #endif
  
          /* 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 = blockSize % 0x4u;
  
  #else
  
      /* Run the below code for Cortex-M0 */
  
      /* Loop over blockSize number of values */
      blkCnt = blockSize;
  
  #endif /* #ifndef ARM_MATH_CM0_FAMILY */
  
      while (blkCnt > 0u)
      {
          /* C = (q15_t) A << 8 */
          /* convert from q7 to q15 and then store the results in the destination buffer */
          *pDst++ = (q15_t)*pIn++;
  
          /* Decrement the loop counter */
          blkCnt--;
      }
  }
  
  /**
   * @} end of q7_to_x group
   */
  