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author | JanHenrik <janhenrik@janhenrik.org> | 2020-04-01 00:40:03 +0200 |
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committer | JanHenrik <janhenrik@janhenrik.org> | 2020-04-01 00:40:03 +0200 |
commit | f7de54fc6fa6b40dfa2dfbe4c2a8ee933affa126 (patch) | |
tree | 78465e38a01011dc9f17eb73416011310532017f /cdc-dials/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q31.c | |
parent | 3ec13d81e70e52246545c720abe756ccf09fb231 (diff) | |
download | minikbd-f7de54fc6fa6b40dfa2dfbe4c2a8ee933affa126.tar.gz minikbd-f7de54fc6fa6b40dfa2dfbe4c2a8ee933affa126.tar.bz2 minikbd-f7de54fc6fa6b40dfa2dfbe4c2a8ee933affa126.zip |
added files
Diffstat (limited to 'cdc-dials/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q31.c')
-rw-r--r-- | cdc-dials/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q31.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/cdc-dials/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q31.c b/cdc-dials/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q31.c new file mode 100644 index 0000000..def314a --- /dev/null +++ b/cdc-dials/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_mean_q31.c @@ -0,0 +1,123 @@ +/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_mean_q31.c
+ * Description: Mean value of a Q31 vector
+ *
+ * $Date: 27. January 2017
+ * $Revision: V.1.5.1
+ *
+ * Target Processor: Cortex-M cores
+ * -------------------------------------------------------------------- */
+/*
+ * Copyright (C) 2010-2017 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 "arm_math.h"
+
+/**
+ * @ingroup groupStats
+ */
+
+/**
+ * @addtogroup mean
+ * @{
+ */
+
+
+/**
+ * @brief Mean value of a Q31 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 64-bit internal accumulator.
+ * The input is represented in 1.31 format and is accumulated in a 64-bit
+ * accumulator in 33.31 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 1.31 format.
+ *
+ */
+
+void arm_mean_q31(
+ q31_t * pSrc,
+ uint32_t blockSize,
+ q31_t * pResult)
+{
+ q63_t sum = 0; /* Temporary result storage */
+ uint32_t blkCnt; /* loop counter */
+
+#if defined (ARM_MATH_DSP)
+ /* Run the below code for Cortex-M4 and Cortex-M3 */
+
+ q31_t in1, in2, in3, in4;
+
+ /*loop Unrolling */
+ 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]) */
+ in1 = *pSrc++;
+ in2 = *pSrc++;
+ in3 = *pSrc++;
+ in4 = *pSrc++;
+
+ sum += in1;
+ sum += in2;
+ sum += in3;
+ sum += in4;
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+ /* If the blockSize is not a multiple of 4, compute any remaining output samples here.
+ ** No loop unrolling is used. */
+ blkCnt = blockSize % 0x4U;
+
+#else
+ /* Run the below code for Cortex-M0 */
+
+ /* Loop over blockSize number of values */
+ blkCnt = blockSize;
+
+#endif /* #if defined (ARM_MATH_DSP) */
+
+ while (blkCnt > 0U)
+ {
+ /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) */
+ sum += *pSrc++;
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+ /* C = (A[0] + A[1] + A[2] + ... + A[blockSize-1]) / blockSize */
+ /* Store the result to the destination */
+ *pResult = (q31_t) (sum / (int32_t) blockSize);
+}
+
+/**
+ * @} end of mean group
+ */
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