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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_shift_q15.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_shift_q15.c')
-rw-r--r-- | DSP/Source/BasicMathFunctions/arm_shift_q15.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/DSP/Source/BasicMathFunctions/arm_shift_q15.c b/DSP/Source/BasicMathFunctions/arm_shift_q15.c new file mode 100644 index 0000000..d2cd037 --- /dev/null +++ b/DSP/Source/BasicMathFunctions/arm_shift_q15.c @@ -0,0 +1,236 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_shift_q15.c + * Description: Shifts the elements of a Q15 vector by a specified number of bits + * + * $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 + */ + +/** + * @addtogroup shift + * @{ + */ + +/** + * @brief Shifts the elements of a Q15 vector a specified number of bits. + * @param[in] *pSrc points to the input vector + * @param[in] shiftBits number of bits to shift. A positive value shifts left; a negative value shifts right. + * @param[out] *pDst points to the output vector + * @param[in] blockSize number of samples in the vector + * @return none. + * + * <b>Scaling and Overflow Behavior:</b> + * \par + * The function uses saturating arithmetic. + * Results outside of the allowable Q15 range [0x8000 0x7FFF] will be saturated. + */ + +void arm_shift_q15( + q15_t * pSrc, + int8_t shiftBits, + q15_t * pDst, + uint32_t blockSize) +{ + uint32_t blkCnt; /* loop counter */ + uint8_t sign; /* Sign of shiftBits */ + +#if defined (ARM_MATH_DSP) + +/* Run the below code for Cortex-M4 and Cortex-M3 */ + + q15_t in1, in2; /* Temporary variables */ + + + /*loop Unrolling */ + blkCnt = blockSize >> 2U; + + /* Getting the sign of shiftBits */ + sign = (shiftBits & 0x80); + + /* If the shift value is positive then do right shift else left shift */ + if (sign == 0U) + { + /* 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) + { + /* Read 2 inputs */ + in1 = *pSrc++; + in2 = *pSrc++; + /* C = A << shiftBits */ + /* Shift the inputs and then store the results in the destination buffer. */ +#ifndef ARM_MATH_BIG_ENDIAN + + *__SIMD32(pDst)++ = __PKHBT(__SSAT((in1 << shiftBits), 16), + __SSAT((in2 << shiftBits), 16), 16); + +#else + + *__SIMD32(pDst)++ = __PKHBT(__SSAT((in2 << shiftBits), 16), + __SSAT((in1 << shiftBits), 16), 16); + +#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ + + in1 = *pSrc++; + in2 = *pSrc++; + +#ifndef ARM_MATH_BIG_ENDIAN + + *__SIMD32(pDst)++ = __PKHBT(__SSAT((in1 << shiftBits), 16), + __SSAT((in2 << shiftBits), 16), 16); + +#else + + *__SIMD32(pDst)++ = __PKHBT(__SSAT((in2 << shiftBits), 16), + __SSAT((in1 << shiftBits), 16), 16); + +#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ + + /* 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; + + while (blkCnt > 0U) + { + /* C = A << shiftBits */ + /* Shift and then store the results in the destination buffer. */ + *pDst++ = __SSAT((*pSrc++ << shiftBits), 16); + + /* Decrement the loop counter */ + blkCnt--; + } + } + else + { + /* 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) + { + /* Read 2 inputs */ + in1 = *pSrc++; + in2 = *pSrc++; + + /* C = A >> shiftBits */ + /* Shift the inputs and then store the results in the destination buffer. */ +#ifndef ARM_MATH_BIG_ENDIAN + + *__SIMD32(pDst)++ = __PKHBT((in1 >> -shiftBits), + (in2 >> -shiftBits), 16); + +#else + + *__SIMD32(pDst)++ = __PKHBT((in2 >> -shiftBits), + (in1 >> -shiftBits), 16); + +#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ + + in1 = *pSrc++; + in2 = *pSrc++; + +#ifndef ARM_MATH_BIG_ENDIAN + + *__SIMD32(pDst)++ = __PKHBT((in1 >> -shiftBits), + (in2 >> -shiftBits), 16); + +#else + + *__SIMD32(pDst)++ = __PKHBT((in2 >> -shiftBits), + (in1 >> -shiftBits), 16); + +#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ + + /* 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; + + while (blkCnt > 0U) + { + /* C = A >> shiftBits */ + /* Shift the inputs and then store the results in the destination buffer. */ + *pDst++ = (*pSrc++ >> -shiftBits); + + /* Decrement the loop counter */ + blkCnt--; + } + } + +#else + + /* Run the below code for Cortex-M0 */ + + /* Getting the sign of shiftBits */ + sign = (shiftBits & 0x80); + + /* If the shift value is positive then do right shift else left shift */ + if (sign == 0U) + { + /* Initialize blkCnt with number of samples */ + blkCnt = blockSize; + + while (blkCnt > 0U) + { + /* C = A << shiftBits */ + /* Shift and then store the results in the destination buffer. */ + *pDst++ = __SSAT(((q31_t) * pSrc++ << shiftBits), 16); + + /* Decrement the loop counter */ + blkCnt--; + } + } + else + { + /* Initialize blkCnt with number of samples */ + blkCnt = blockSize; + + while (blkCnt > 0U) + { + /* C = A >> shiftBits */ + /* Shift the inputs and then store the results in the destination buffer. */ + *pDst++ = (*pSrc++ >> -shiftBits); + + /* Decrement the loop counter */ + blkCnt--; + } + } + +#endif /* #if defined (ARM_MATH_DSP) */ + +} + +/** + * @} end of shift group + */ |