diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_scale_q15.c')
| -rw-r--r-- | Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_scale_q15.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_scale_q15.c b/Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_scale_q15.c new file mode 100644 index 0000000..fc3f2ee --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_scale_q15.c @@ -0,0 +1,144 @@ +/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_scale_q15.c
+ * Description: Multiplies a Q15 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
+ */
+
+/**
+ @addtogroup BasicScale
+ @{
+ */
+
+/**
+ @brief Multiplies a Q15 vector by a scalar.
+ @param[in] pSrc points to the input vector
+ @param[in] scaleFract fractional portion of the scale value
+ @param[in] shift number of bits to shift the result by
+ @param[out] pDst points to the output vector
+ @param[in] blockSize number of samples in each vector
+ @return none
+
+ @par Scaling and Overflow Behavior
+ The input data <code>*pSrc</code> and <code>scaleFract</code> are in 1.15 format.
+ These are multiplied to yield a 2.30 intermediate result and this is shifted with saturation to 1.15 format.
+ */
+
+void arm_scale_q15(
+ const q15_t *pSrc,
+ q15_t scaleFract,
+ int8_t shift,
+ q15_t *pDst,
+ uint32_t blockSize)
+{
+ uint32_t blkCnt; /* Loop counter */
+ int8_t kShift = 15 - shift; /* Shift to apply after scaling */
+
+#if defined (ARM_MATH_LOOPUNROLL)
+#if defined (ARM_MATH_DSP)
+ q31_t inA1, inA2;
+ q31_t out1, out2, out3, out4; /* Temporary output variables */
+ q15_t in1, in2, in3, in4; /* Temporary input variables */
+#endif
+#endif
+
+#if defined (ARM_MATH_LOOPUNROLL)
+
+ /* Loop unrolling: Compute 4 outputs at a time */
+ blkCnt = blockSize >> 2U;
+
+ while (blkCnt > 0U)
+ {
+ /* C = A * scale */
+
+#if defined (ARM_MATH_DSP)
+ /* read 2 times 2 samples at a time from source */
+ inA1 = read_q15x2_ia ((q15_t **) &pSrc);
+ inA2 = read_q15x2_ia ((q15_t **) &pSrc);
+
+ /* Scale inputs and store result in temporary variables
+ * in single cycle by packing the outputs */
+ out1 = (q31_t) ((q15_t) (inA1 >> 16) * scaleFract);
+ out2 = (q31_t) ((q15_t) (inA1 ) * scaleFract);
+ out3 = (q31_t) ((q15_t) (inA2 >> 16) * scaleFract);
+ out4 = (q31_t) ((q15_t) (inA2 ) * scaleFract);
+
+ /* apply shifting */
+ out1 = out1 >> kShift;
+ out2 = out2 >> kShift;
+ out3 = out3 >> kShift;
+ out4 = out4 >> kShift;
+
+ /* saturate the output */
+ in1 = (q15_t) (__SSAT(out1, 16));
+ in2 = (q15_t) (__SSAT(out2, 16));
+ in3 = (q15_t) (__SSAT(out3, 16));
+ in4 = (q15_t) (__SSAT(out4, 16));
+
+ /* store result to destination */
+ write_q15x2_ia (&pDst, __PKHBT(in2, in1, 16));
+ write_q15x2_ia (&pDst, __PKHBT(in4, in3, 16));
+#else
+ *pDst++ = (q15_t) (__SSAT(((q31_t) *pSrc++ * scaleFract) >> kShift, 16));
+ *pDst++ = (q15_t) (__SSAT(((q31_t) *pSrc++ * scaleFract) >> kShift, 16));
+ *pDst++ = (q15_t) (__SSAT(((q31_t) *pSrc++ * scaleFract) >> kShift, 16));
+ *pDst++ = (q15_t) (__SSAT(((q31_t) *pSrc++ * scaleFract) >> kShift, 16));
+#endif
+
+ /* 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) */
+
+ while (blkCnt > 0U)
+ {
+ /* C = A * scale */
+
+ /* Scale input and store result in destination buffer. */
+ *pDst++ = (q15_t) (__SSAT(((q31_t) *pSrc++ * scaleFract) >> kShift, 16));
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+}
+
+/**
+ @} end of BasicScale group
+ */
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