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author | Ali Labbene <ali.labbene@st.com> | 2019-12-11 08:59:21 +0100 |
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committer | Ali Labbene <ali.labbene@st.com> | 2019-12-16 16:35:24 +0100 |
commit | 9f95ff5b6ba01db09552b84a0ab79607060a2666 (patch) | |
tree | 8a6e0dda832555c692307869aed49d07ee7facfe /DSP/Source/BasicMathFunctions/arm_scale_f32.c | |
parent | 76177aa280494bb36d7a0bcbda1078d4db717020 (diff) | |
download | st-cmsis-core-lowfat-9f95ff5b6ba01db09552b84a0ab79607060a2666.tar.gz st-cmsis-core-lowfat-9f95ff5b6ba01db09552b84a0ab79607060a2666.tar.bz2 st-cmsis-core-lowfat-9f95ff5b6ba01db09552b84a0ab79607060a2666.zip |
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
Diffstat (limited to 'DSP/Source/BasicMathFunctions/arm_scale_f32.c')
-rw-r--r-- | DSP/Source/BasicMathFunctions/arm_scale_f32.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/DSP/Source/BasicMathFunctions/arm_scale_f32.c b/DSP/Source/BasicMathFunctions/arm_scale_f32.c new file mode 100644 index 0000000..c90c037 --- /dev/null +++ b/DSP/Source/BasicMathFunctions/arm_scale_f32.c @@ -0,0 +1,157 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_scale_f32.c + * Description: Multiplies a floating-point vector by a scalar + * + * $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 groupMath + */ + +/** + * @defgroup scale 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 scale + * @{ + */ + +/** + * @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 the vector + * @return none. + */ + + +void arm_scale_f32( + float32_t * pSrc, + float32_t scale, + float32_t * pDst, + uint32_t blockSize) +{ + uint32_t blkCnt; /* loop counter */ +#if defined (ARM_MATH_DSP) + +/* Run the below code for Cortex-M4 and Cortex-M3 */ + float32_t in1, in2, in3, in4; /* temporary variabels */ + + /*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 * scale */ + /* Scale the input and then store the results in the destination buffer. */ + /* read input samples from source */ + in1 = *pSrc; + in2 = *(pSrc + 1); + + /* multiply with scaling factor */ + in1 = in1 * scale; + + /* read input sample from source */ + in3 = *(pSrc + 2); + + /* multiply with scaling factor */ + in2 = in2 * scale; + + /* read input sample from source */ + in4 = *(pSrc + 3); + + /* multiply with scaling factor */ + in3 = in3 * scale; + in4 = in4 * scale; + /* store the result to destination */ + *pDst = in1; + *(pDst + 1) = in2; + *(pDst + 2) = in3; + *(pDst + 3) = in4; + + /* update pointers to process next samples */ + pSrc += 4U; + pDst += 4U; + + /* 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 */ + + /* Initialize blkCnt with number of samples */ + blkCnt = blockSize; + +#endif /* #if defined (ARM_MATH_DSP) */ + + while (blkCnt > 0U) + { + /* C = A * scale */ + /* Scale the input and then store the result in the destination buffer. */ + *pDst++ = (*pSrc++) * scale; + + /* Decrement the loop counter */ + blkCnt--; + } +} + +/** + * @} end of scale group + */ |