diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_scale_f32.c')
-rw-r--r-- | Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_scale_f32.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_scale_f32.c b/Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_scale_f32.c new file mode 100644 index 0000000..38327cc --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_scale_f32.c @@ -0,0 +1,159 @@ +/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_scale_f32.c
+ * Description: Multiplies a floating-point vector by a scalar
+ *
+ * $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 groupMath
+ */
+
+/**
+ @defgroup BasicScale Vector Scale
+
+ Multiply a vector by a scalar value. For floating-point data, the algorithm used is:
+
+ <pre>
+ pDst[n] = pSrc[n] * scale, 0 <= n < blockSize.
+ </pre>
+
+ In the fixed-point Q7, Q15, and Q31 functions, <code>scale</code> is represented by
+ a fractional multiplication <code>scaleFract</code> and an arithmetic shift <code>shift</code>.
+ The shift allows the gain of the scaling operation to exceed 1.0.
+ The algorithm used with fixed-point data is:
+
+ <pre>
+ pDst[n] = (pSrc[n] * scaleFract) << shift, 0 <= n < blockSize.
+ </pre>
+
+ The overall scale factor applied to the fixed-point data is
+ <pre>
+ scale = scaleFract * 2^shift.
+ </pre>
+
+ The functions support in-place computation allowing the source and destination
+ pointers to reference the same memory buffer.
+ */
+
+/**
+ @addtogroup BasicScale
+ @{
+ */
+
+/**
+ @brief Multiplies a floating-point vector by a scalar.
+ @param[in] pSrc points to the input vector
+ @param[in] scale scale factor to be applied
+ @param[out] pDst points to the output vector
+ @param[in] blockSize number of samples in each vector
+ @return none
+ */
+
+void arm_scale_f32(
+ const float32_t *pSrc,
+ float32_t scale,
+ float32_t *pDst,
+ uint32_t blockSize)
+{
+ uint32_t blkCnt; /* Loop counter */
+#if defined(ARM_MATH_NEON_EXPERIMENTAL)
+ float32x4_t vec1;
+ float32x4_t res;
+
+ /* Compute 4 outputs at a time */
+ blkCnt = blockSize >> 2U;
+
+ while (blkCnt > 0U)
+ {
+ /* C = A * scale */
+
+ /* Scale the input and then store the results in the destination buffer. */
+ vec1 = vld1q_f32(pSrc);
+ res = vmulq_f32(vec1, vdupq_n_f32(scale));
+ vst1q_f32(pDst, res);
+
+ /* Increment pointers */
+ pSrc += 4;
+ pDst += 4;
+
+ /* Decrement the loop counter */
+ blkCnt--;
+ }
+
+ /* Tail */
+ blkCnt = blockSize & 0x3;
+
+#else
+#if defined (ARM_MATH_LOOPUNROLL)
+
+ /* Loop unrolling: Compute 4 outputs at a time */
+ blkCnt = blockSize >> 2U;
+
+ while (blkCnt > 0U)
+ {
+ /* C = A * scale */
+
+ /* Scale input and store result in destination buffer. */
+ *pDst++ = (*pSrc++) * scale;
+
+ *pDst++ = (*pSrc++) * scale;
+
+ *pDst++ = (*pSrc++) * scale;
+
+ *pDst++ = (*pSrc++) * scale;
+
+ /* Decrement 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) */
+#endif /* #if defined(ARM_MATH_NEON_EXPERIMENTAL) */
+
+ while (blkCnt > 0U)
+ {
+ /* C = A * scale */
+
+ /* Scale input and store result in destination buffer. */
+ *pDst++ = (*pSrc++) * scale;
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+}
+
+/**
+ @} end of BasicScale group
+ */
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