arm_q7_to_q31.c

00001 /* ----------------------------------------------------------------------
00002  * Project:      CMSIS DSP Library
00003  * Title:        arm_q7_to_q31.c
00004  * Description:  Converts the elements of the Q7 vector to Q31 vector
00005  *
00006  * $Date:        27. January 2017
00007  * $Revision:    V.1.5.1
00008  *
00009  * Target Processor: Cortex-M cores
00010  * -------------------------------------------------------------------- */
00011 /*
00012  * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
00013  *
00014  * SPDX-License-Identifier: Apache-2.0
00015  *
00016  * Licensed under the Apache License, Version 2.0 (the License); you may
00017  * not use this file except in compliance with the License.
00018  * You may obtain a copy of the License at
00019  *
00020  * www.apache.org/licenses/LICENSE-2.0
00021  *
00022  * Unless required by applicable law or agreed to in writing, software
00023  * distributed under the License is distributed on an AS IS BASIS, WITHOUT
00024  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00025  * See the License for the specific language governing permissions and
00026  * limitations under the License.
00027  */
00028 
00029 #include "arm_math.h"
00030 
00031 /**
00032  * @ingroup groupSupport
00033  */
00034 
00035 /**
00036  * @addtogroup q7_to_x
00037  * @{
00038  */
00039 
00040 /**
00041  * @brief Converts the elements of the Q7 vector to Q31 vector.
00042  * @param[in]       *pSrc points to the Q7 input vector
00043  * @param[out]      *pDst points to the Q31 output vector
00044  * @param[in]       blockSize length of the input vector
00045  * @return none.
00046  *
00047  * \par Description:
00048  *
00049  * The equation used for the conversion process is:
00050  *
00051  * <pre>
00052  *  pDst[n] = (q31_t) pSrc[n] << 24;   0 <= n < blockSize.
00053  * </pre>
00054  *
00055  */
00056 
00057 
00058 void arm_q7_to_q31(
00059   q7_t * pSrc,
00060   q31_t * pDst,
00061   uint32_t blockSize)
00062 {
00063   q7_t *pIn = pSrc;                              /* Src pointer */
00064   uint32_t blkCnt;                               /* loop counter */
00065 
00066 #if defined (ARM_MATH_DSP)
00067 
00068   q31_t in;
00069 
00070   /* Run the below code for Cortex-M4 and Cortex-M3 */
00071 
00072   /*loop Unrolling */
00073   blkCnt = blockSize >> 2U;
00074 
00075   /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
00076    ** a second loop below computes the remaining 1 to 3 samples. */
00077   while (blkCnt > 0U)
00078   {
00079     /* C = (q31_t) A << 24 */
00080     /* convert from q7 to q31 and then store the results in the destination buffer */
00081     in = *__SIMD32(pIn)++;
00082 
00083 #ifndef ARM_MATH_BIG_ENDIAN
00084 
00085     *pDst++ = (__ROR(in, 8)) & 0xFF000000;
00086     *pDst++ = (__ROR(in, 16)) & 0xFF000000;
00087     *pDst++ = (__ROR(in, 24)) & 0xFF000000;
00088     *pDst++ = (in & 0xFF000000);
00089 
00090 #else
00091 
00092     *pDst++ = (in & 0xFF000000);
00093     *pDst++ = (__ROR(in, 24)) & 0xFF000000;
00094     *pDst++ = (__ROR(in, 16)) & 0xFF000000;
00095     *pDst++ = (__ROR(in, 8)) & 0xFF000000;
00096 
00097 #endif //              #ifndef ARM_MATH_BIG_ENDIAN
00098 
00099     /* Decrement the loop counter */
00100     blkCnt--;
00101   }
00102 
00103   /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
00104    ** No loop unrolling is used. */
00105   blkCnt = blockSize % 0x4U;
00106 
00107 #else
00108 
00109   /* Run the below code for Cortex-M0 */
00110 
00111   /* Loop over blockSize number of values */
00112   blkCnt = blockSize;
00113 
00114 #endif /* #if defined (ARM_MATH_DSP) */
00115 
00116   while (blkCnt > 0U)
00117   {
00118     /* C = (q31_t) A << 24 */
00119     /* convert from q7 to q31 and then store the results in the destination buffer */
00120     *pDst++ = (q31_t) * pIn++ << 24;
00121 
00122     /* Decrement the loop counter */
00123     blkCnt--;
00124   }
00125 
00126 }
00127 
00128 /**
00129  * @} end of q7_to_x group
00130  */
00131