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authorAli Labbene <ali.labbene@st.com>2019-12-11 08:59:21 +0100
committerAli Labbene <ali.labbene@st.com>2019-12-16 16:35:24 +0100
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Official ARM version: v5.4.0
Add CMSIS V5.4.0, please refer to index.html available under \docs folder. Note: content of \CMSIS\Core\Include has been copied under \Include to keep the same structure used in existing projects, and thus avoid projects mass update Note: the following components have been removed from ARM original delivery (as not used in ST packages) - CMSIS_EW2018.pdf - .gitattributes - .gitignore - \Device - \CMSIS - \CoreValidation - \DAP - \Documentation - \DoxyGen - \Driver - \Pack - \RTOS\CMSIS_RTOS_Tutorial.pdf - \RTOS\RTX - \RTOS\Template - \RTOS2\RTX - \Utilities - All ARM/GCC projects files are deleted from \DSP, \RTOS and \RTOS2 Change-Id: Ia026c3f0f0d016627a4fb5a9032852c33d24b4d3
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+/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_power_q7.c
+ * Description: Sum of the squares of the elements of a Q7 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 power
+ * @{
+ */
+
+/**
+ * @brief Sum of the squares of the elements of a Q7 vector.
+ * @param[in] *pSrc points to the input vector
+ * @param[in] blockSize length of the input vector
+ * @param[out] *pResult sum of the squares 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 1.7 format.
+ * Intermediate multiplication yields a 2.14 format, and this
+ * result is added without saturation to an accumulator in 18.14 format.
+ * With 17 guard bits in the accumulator, there is no risk of overflow, and the
+ * full precision of the intermediate multiplication is preserved.
+ * Finally, the return result is in 18.14 format.
+ *
+ */
+
+void arm_power_q7(
+ q7_t * pSrc,
+ uint32_t blockSize,
+ q31_t * pResult)
+{
+ q31_t sum = 0; /* Temporary result storage */
+ q7_t in; /* Temporary variable to store input */
+ uint32_t blkCnt; /* loop counter */
+
+#if defined (ARM_MATH_DSP)
+ /* Run the below code for Cortex-M4 and Cortex-M3 */
+
+ q31_t input1; /* Temporary variable to store packed input */
+ q31_t in1, in2; /* Temporary variables to store input */
+
+ /*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)
+ {
+ /* Reading two inputs of pSrc vector and packing */
+ input1 = *__SIMD32(pSrc)++;
+
+ in1 = __SXTB16(__ROR(input1, 8));
+ in2 = __SXTB16(input1);
+
+ /* C = A[0] * A[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
+ /* calculate power and accumulate to accumulator */
+ sum = __SMLAD(in1, in1, sum);
+ sum = __SMLAD(in2, in2, sum);
+
+ /* 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[0] + A[1] * A[1] + A[2] * A[2] + ... + A[blockSize-1] * A[blockSize-1] */
+ /* Compute Power and then store the result in a temporary variable, sum. */
+ in = *pSrc++;
+ sum += ((q15_t) in * in);
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+ /* Store the result in 18.14 format */
+ *pResult = sum;
+}
+
+/**
+ * @} end of power group
+ */