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Diffstat (limited to 'platform/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_shift_q15.c')
| -rw-r--r-- | platform/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_shift_q15.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/platform/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_shift_q15.c b/platform/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_shift_q15.c new file mode 100644 index 0000000..3ea0de9 --- /dev/null +++ b/platform/CMSIS/DSP_Lib/Source/BasicMathFunctions/arm_shift_q15.c @@ -0,0 +1,248 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2014 ARM Limited. All rights reserved. +* +* $Date: 12. March 2014 +* $Revision: V1.4.4 +* +* Project: CMSIS DSP Library +* Title: arm_shift_q15.c +* +* Description: Shifts the elements of a Q15 vector by a specified number of bits. +* +* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 +* +* Redistribution and use in source and binary forms, with or without +* modification, are permitted provided that the following conditions +* are met: +* - Redistributions of source code must retain the above copyright +* notice, this list of conditions and the following disclaimer. +* - Redistributions in binary form must reproduce the above copyright +* notice, this list of conditions and the following disclaimer in +* the documentation and/or other materials provided with the +* distribution. +* - Neither the name of ARM LIMITED nor the names of its contributors +* may be used to endorse or promote products derived from this +* software without specific prior written permission. +* +* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +* POSSIBILITY OF SUCH DAMAGE. +* -------------------------------------------------------------------- */ + +#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 */ + +#ifndef ARM_MATH_CM0_FAMILY + +/* 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 /* #ifndef ARM_MATH_CM0_FAMILY */ + +} + +/** + * @} end of shift group + */ |