diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q15.c')
| -rw-r--r-- | Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q15.c | 84 |
1 files changed, 39 insertions, 45 deletions
diff --git a/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q15.c b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q15.c index 7bf55c2ff..463aa84ec 100644 --- a/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q15.c +++ b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q15.c @@ -3,13 +3,13 @@ * Title: arm_mean_q15.c * Description: Mean value of a Q15 vector * - * $Date: 27. January 2017 - * $Revision: V.1.5.1 + * $Date: 18. March 2019 + * $Revision: V1.6.0 * * Target Processor: Cortex-M cores * -------------------------------------------------------------------- */ /* - * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved. + * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved. * * SPDX-License-Identifier: Apache-2.0 * @@ -29,59 +29,55 @@ #include "arm_math.h" /** - * @ingroup groupStats + @ingroup groupStats */ /** - * @addtogroup mean - * @{ + @addtogroup mean + @{ */ - /** - * @brief Mean value of a Q15 vector. - * @param[in] *pSrc points to the input vector - * @param[in] blockSize length of the input vector - * @param[out] *pResult mean value returned here - * @return none. - * - * @details - * <b>Scaling and Overflow Behavior:</b> - * \par - * The function is implemented using a 32-bit internal accumulator. - * The input is represented in 1.15 format and is accumulated in a 32-bit - * accumulator in 17.15 format. - * There is no risk of internal overflow with this approach, and the - * full precision of intermediate result is preserved. - * Finally, the accumulator is saturated and truncated to yield a result of 1.15 format. - * + @brief Mean value of a Q15 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 1.15 format and is accumulated in a 32-bit + accumulator in 17.15 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 1.15 format. */ void arm_mean_q15( - q15_t * pSrc, - uint32_t blockSize, - q15_t * pResult) + const q15_t * pSrc, + uint32_t blockSize, + q15_t * pResult) { - q31_t sum = 0; /* Temporary result storage */ - uint32_t blkCnt; /* loop counter */ + uint32_t blkCnt; /* Loop counter */ + q31_t sum = 0; /* Temporary result storage */ -#if defined (ARM_MATH_DSP) - /* Run the below code for Cortex-M4 and Cortex-M3 */ +#if defined (ARM_MATH_LOOPUNROLL) + q31_t in; +#endif - q31_t in; +#if defined (ARM_MATH_LOOPUNROLL) - /*loop Unrolling */ + /* Loop unrolling: Compute 4 outputs at a time */ 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 = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */ - in = *__SIMD32(pSrc)++; + in = read_q15x2_ia ((q15_t **) &pSrc); sum += ((in << 16U) >> 16U); sum += (in >> 16U); - in = *__SIMD32(pSrc)++; + + in = read_q15x2_ia ((q15_t **) &pSrc); sum += ((in << 16U) >> 16U); sum += (in >> 16U); @@ -89,32 +85,30 @@ void arm_mean_q15( blkCnt--; } - /* If the blockSize is not a multiple of 4, compute any remaining output samples here. - ** No loop unrolling is used. */ + /* Loop unrolling: Compute remaining outputs */ blkCnt = blockSize % 0x4U; #else - /* Run the below code for Cortex-M0 */ - /* Loop over blockSize number of values */ + /* Initialize blkCnt with number of samples */ blkCnt = blockSize; -#endif /* #if defined (ARM_MATH_DSP) */ +#endif /* #if defined (ARM_MATH_LOOPUNROLL) */ while (blkCnt > 0U) { /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */ sum += *pSrc++; - /* Decrement the loop counter */ + /* Decrement loop counter */ blkCnt--; } /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) / blockSize */ - /* Store the result to the destination */ - *pResult = (q15_t) (sum / (q31_t)blockSize); + /* Store result to destination */ + *pResult = (q15_t) (sum / (int32_t) blockSize); } /** - * @} end of mean group + @} end of mean group */ |