text: /* ----------------------------------------------------------------------
   * Project:      CMSIS DSP Library
   * Title:        arm_q7_to_q31.c
   * Description:  Converts the elements of the Q7 vector to Q31 vector
   *
   * $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 groupSupport
   */
  
  /**
   * @addtogroup q7_to_x
   * @{
   */
  
  /**
   * @brief Converts the elements of the Q7 vector to Q31 vector.
   * @param[in]       *pSrc points to the Q7 input vector
   * @param[out]      *pDst points to the Q31 output vector
   * @param[in]       blockSize length of the input vector
   * @return none.
   *
   * \par Description:
   *
   * The equation used for the conversion process is:
   *
   * <pre>
   * 	pDst[n] = (q31_t) pSrc[n] << 24;   0 <= n < blockSize.
   * </pre>
   *
   */
  
  
  void arm_q7_to_q31(
    const q7_t * pSrc,
    q31_t * pDst,
    uint32_t blockSize)
  {
    const q7_t *pIn = pSrc;                        /* Src pointer */
    uint32_t blkCnt;                               /* loop counter */
  
  #if defined (ARM_MATH_DSP)
  
    q31_t in;
  
    /* 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 = (q31_t) A << 24 */
      /* convert from q7 to q31 and then store the results in the destination buffer */
      in = *__SIMD32(pIn)++;
  
  #ifndef ARM_MATH_BIG_ENDIAN
  
      *pDst++ = (__ROR(in, 8)) & 0xFF000000;
      *pDst++ = (__ROR(in, 16)) & 0xFF000000;
      *pDst++ = (__ROR(in, 24)) & 0xFF000000;
      *pDst++ = (in & 0xFF000000);
  
  #else
  
      *pDst++ = (in & 0xFF000000);
      *pDst++ = (__ROR(in, 24)) & 0xFF000000;
      *pDst++ = (__ROR(in, 16)) & 0xFF000000;
      *pDst++ = (__ROR(in, 8)) & 0xFF000000;
  
  #endif //              #ifndef ARM_MATH_BIG_ENDIAN
  
      /* 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 /* #if defined (ARM_MATH_DSP) */
  
    while (blkCnt > 0U)
    {
      /* C = (q31_t) A << 24 */
      /* convert from q7 to q31 and then store the results in the destination buffer */
      *pDst++ = (q31_t) * pIn++ << 24;
  
      /* Decrement the loop counter */
      blkCnt--;
    }
  
  }
  
  /**
   * @} end of q7_to_x group
   */
  