summaryrefslogtreecommitdiff
path: root/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_max_q31.c
diff options
context:
space:
mode:
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_max_q31.c')
-rw-r--r--Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_max_q31.c148
1 files changed, 148 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_max_q31.c b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_max_q31.c
new file mode 100644
index 0000000..5c6badf
--- /dev/null
+++ b/Drivers/CMSIS/DSP/Source/StatisticsFunctions/arm_max_q31.c
@@ -0,0 +1,148 @@
+/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_max_q31.c
+ * Description: Maximum value of a Q31 vector
+ *
+ * $Date: 18. March 2019
+ * $Revision: V1.6.0
+ *
+ * Target Processor: Cortex-M cores
+ * -------------------------------------------------------------------- */
+/*
+ * Copyright (C) 2010-2019 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 Max
+ @{
+ */
+
+/**
+ @brief Maximum value of a Q31 vector.
+ @param[in] pSrc points to the input vector
+ @param[in] blockSize number of samples in input vector
+ @param[out] pResult maximum value returned here
+ @param[out] pIndex index of maximum value returned here
+ @return none
+ */
+
+void arm_max_q31(
+ const q31_t * pSrc,
+ uint32_t blockSize,
+ q31_t * pResult,
+ uint32_t * pIndex)
+{
+ q31_t maxVal, out; /* Temporary variables to store the output value. */
+ uint32_t blkCnt, outIndex; /* Loop counter */
+
+#if defined (ARM_MATH_LOOPUNROLL)
+ uint32_t index; /* index of maximum value */
+#endif
+
+ /* Initialise index value to zero. */
+ outIndex = 0U;
+ /* Load first input value that act as reference value for comparision */
+ out = *pSrc++;
+
+#if defined (ARM_MATH_LOOPUNROLL)
+ /* Initialise index of maximum value. */
+ index = 0U;
+
+ /* Loop unrolling: Compute 4 outputs at a time */
+ blkCnt = (blockSize - 1U) >> 2U;
+
+ while (blkCnt > 0U)
+ {
+ /* Initialize maxVal to next consecutive values one by one */
+ maxVal = *pSrc++;
+
+ /* compare for the maximum value */
+ if (out < maxVal)
+ {
+ /* Update the maximum value and it's index */
+ out = maxVal;
+ outIndex = index + 1U;
+ }
+
+ maxVal = *pSrc++;
+ if (out < maxVal)
+ {
+ out = maxVal;
+ outIndex = index + 2U;
+ }
+
+ maxVal = *pSrc++;
+ if (out < maxVal)
+ {
+ out = maxVal;
+ outIndex = index + 3U;
+ }
+
+ maxVal = *pSrc++;
+ if (out < maxVal)
+ {
+ out = maxVal;
+ outIndex = index + 4U;
+ }
+
+ index += 4U;
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+ /* Loop unrolling: Compute remaining outputs */
+ blkCnt = (blockSize - 1U) % 4U;
+
+#else
+
+ /* Initialize blkCnt with number of samples */
+ blkCnt = (blockSize - 1U);
+
+#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
+
+ while (blkCnt > 0U)
+ {
+ /* Initialize maxVal to the next consecutive values one by one */
+ maxVal = *pSrc++;
+
+ /* compare for the maximum value */
+ if (out < maxVal)
+ {
+ /* Update the maximum value and it's index */
+ out = maxVal;
+ outIndex = blockSize - blkCnt;
+ }
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+ /* Store the maximum value and it's index into destination pointers */
+ *pResult = out;
+ *pIndex = outIndex;
+}
+
+/**
+ @} end of Max group
+ */