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  1. /* ----------------------------------------------------------------------
  2.  * Project:      CMSIS DSP Library
  3.  * Title:        arm_q7_to_q31.c
  4.  * Description:  Converts the elements of the Q7 vector to Q31 vector
  5.  *
  6.  * $Date:        27. January 2017
  7.  * $Revision:    V.1.5.1
  8.  *
  9.  * Target Processor: Cortex-M cores
  10.  * -------------------------------------------------------------------- */
  11. /*
  12.  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
  13.  *
  14.  * SPDX-License-Identifier: Apache-2.0
  15.  *
  16.  * Licensed under the Apache License, Version 2.0 (the License); you may
  17.  * not use this file except in compliance with the License.
  18.  * You may obtain a copy of the License at
  19.  *
  20.  * www.apache.org/licenses/LICENSE-2.0
  21.  *
  22.  * Unless required by applicable law or agreed to in writing, software
  23.  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
  24.  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  25.  * See the License for the specific language governing permissions and
  26.  * limitations under the License.
  27.  */
  28.  
  29. #include "arm_math.h"
  30.  
  31. /**
  32.  * @ingroup groupSupport
  33.  */
  34.  
  35. /**
  36.  * @addtogroup q7_to_x
  37.  * @{
  38.  */
  39.  
  40. /**
  41.  * @brief Converts the elements of the Q7 vector to Q31 vector.
  42.  * @param[in]       *pSrc points to the Q7 input vector
  43.  * @param[out]      *pDst points to the Q31 output vector
  44.  * @param[in]       blockSize length of the input vector
  45.  * @return none.
  46.  *
  47.  * \par Description:
  48.  *
  49.  * The equation used for the conversion process is:
  50.  *
  51.  * <pre>
  52.  *      pDst[n] = (q31_t) pSrc[n] << 24;   0 <= n < blockSize.
  53.  * </pre>
  54.  *
  55.  */
  56.  
  57.  
  58. void arm_q7_to_q31(
  59.   q7_t * pSrc,
  60.   q31_t * pDst,
  61.   uint32_t blockSize)
  62. {
  63.   q7_t *pIn = pSrc;                              /* Src pointer */
  64.   uint32_t blkCnt;                               /* loop counter */
  65.  
  66. #if defined (ARM_MATH_DSP)
  67.  
  68.   q31_t in;
  69.  
  70.   /* Run the below code for Cortex-M4 and Cortex-M3 */
  71.  
  72.   /*loop Unrolling */
  73.   blkCnt = blockSize >> 2U;
  74.  
  75.   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
  76.    ** a second loop below computes the remaining 1 to 3 samples. */
  77.   while (blkCnt > 0U)
  78.   {
  79.     /* C = (q31_t) A << 24 */
  80.     /* convert from q7 to q31 and then store the results in the destination buffer */
  81.     in = *__SIMD32(pIn)++;
  82.  
  83. #ifndef ARM_MATH_BIG_ENDIAN
  84.  
  85.     *pDst++ = (__ROR(in, 8)) & 0xFF000000;
  86.     *pDst++ = (__ROR(in, 16)) & 0xFF000000;
  87.     *pDst++ = (__ROR(in, 24)) & 0xFF000000;
  88.     *pDst++ = (in & 0xFF000000);
  89.  
  90. #else
  91.  
  92.     *pDst++ = (in & 0xFF000000);
  93.     *pDst++ = (__ROR(in, 24)) & 0xFF000000;
  94.     *pDst++ = (__ROR(in, 16)) & 0xFF000000;
  95.     *pDst++ = (__ROR(in, 8)) & 0xFF000000;
  96.  
  97. #endif //              #ifndef ARM_MATH_BIG_ENDIAN
  98.  
  99.     /* Decrement the loop counter */
  100.     blkCnt--;
  101.   }
  102.  
  103.   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
  104.    ** No loop unrolling is used. */
  105.   blkCnt = blockSize % 0x4U;
  106.  
  107. #else
  108.  
  109.   /* Run the below code for Cortex-M0 */
  110.  
  111.   /* Loop over blockSize number of values */
  112.   blkCnt = blockSize;
  113.  
  114. #endif /* #if defined (ARM_MATH_DSP) */
  115.  
  116.   while (blkCnt > 0U)
  117.   {
  118.     /* C = (q31_t) A << 24 */
  119.     /* convert from q7 to q31 and then store the results in the destination buffer */
  120.     *pDst++ = (q31_t) * pIn++ << 24;
  121.  
  122.     /* Decrement the loop counter */
  123.     blkCnt--;
  124.   }
  125.  
  126. }
  127.  
  128. /**
  129.  * @} end of q7_to_x group
  130.  */
  131.