lib/main/CMSIS/DSP/Source/SupportFunctions/arm_q7_to_q31.c

   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  */