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Diffstat (limited to 'Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q7.c')
| -rw-r--r-- | Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q7.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q7.c b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q7.c new file mode 100644 index 0000000..f0701eb --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q7.c @@ -0,0 +1,153 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_mean_q7.c + * Description: Mean value of a Q7 vector + * + * $Date: 23 April 2021 + * $Revision: V1.9.0 + * + * Target Processor: Cortex-M and Cortex-A cores + * -------------------------------------------------------------------- */ +/* + * Copyright (C) 2010-2021 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 "dsp/statistics_functions.h" + +/** + @ingroup groupStats + */ + +/** + @addtogroup mean + @{ + */ + +/** + @brief Mean value of a Q7 vector. + @param[in] pSrc points to the input vector + @param[in] blockSize number of samples in input vector + @param[out] pResult mean value returned here + @return none + + @par Scaling and Overflow Behavior + The function is implemented using a 32-bit internal accumulator. + The input is represented in 1.7 format and is accumulated in a 32-bit + accumulator in 25.7 format. + There is no risk of internal overflow with this approach, and the + full precision of intermediate result is preserved. + Finally, the accumulator is truncated to yield a result of 1.7 format. + */ + +#if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE) + +void arm_mean_q7( + const q7_t * pSrc, + uint32_t blockSize, + q7_t * pResult) +{ + uint32_t blkCnt; /* loop counters */ + q7x16_t vecSrc; + q31_t sum = 0L; + + + blkCnt = blockSize >> 4; + while (blkCnt > 0U) + { + vecSrc = vldrbq_s8(pSrc); + /* + * sum lanes + */ + sum = vaddvaq(sum, vecSrc); + + blkCnt--; + pSrc += 16; + } + + blkCnt = blockSize & 0xF; + while (blkCnt > 0U) + { + /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */ + sum += *pSrc++; + + /* Decrement loop counter */ + blkCnt--; + } + + /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) / blockSize */ + /* Store the result to the destination */ + *pResult = (q7_t) (sum / (int32_t) blockSize); +} +#else +void arm_mean_q7( + const q7_t * pSrc, + uint32_t blockSize, + q7_t * pResult) +{ + uint32_t blkCnt; /* Loop counter */ + q31_t sum = 0; /* Temporary result storage */ + +#if defined (ARM_MATH_LOOPUNROLL) + q31_t in; +#endif + +#if defined (ARM_MATH_LOOPUNROLL) + + /* Loop unrolling: Compute 4 outputs at a time */ + blkCnt = blockSize >> 2U; + + while (blkCnt > 0U) + { + /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */ + in = read_q7x4_ia (&pSrc); + sum += ((in << 24U) >> 24U); + sum += ((in << 16U) >> 24U); + sum += ((in << 8U) >> 24U); + sum += (in >> 24U); + + /* Decrement the loop counter */ + blkCnt--; + } + + /* Loop unrolling: Compute remaining outputs */ + blkCnt = blockSize % 0x4U; + +#else + + /* Initialize blkCnt with number of samples */ + blkCnt = blockSize; + +#endif /* #if defined (ARM_MATH_LOOPUNROLL) */ + + while (blkCnt > 0U) + { + /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */ + sum += *pSrc++; + + /* Decrement loop counter */ + blkCnt--; + } + + /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) / blockSize */ + /* Store result to destination */ + *pResult = (q7_t) (sum / (int32_t) blockSize); +} +#endif /* defined(ARM_MATH_MVEI) */ + +/** + @} end of mean group + */ |