diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_shift_q31.c')
| -rw-r--r-- | Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_shift_q31.c | 214 |
1 files changed, 102 insertions, 112 deletions
diff --git a/Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_shift_q31.c b/Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_shift_q31.c index 7e728d4ed..db6060adf 100644 --- a/Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_shift_q31.c +++ b/Drivers/CMSIS/DSP/Source/BasicMathFunctions/arm_shift_q31.c @@ -3,13 +3,13 @@ * Title: arm_shift_q31.c * Description: Shifts the elements of a Q31 vector by a specified number of bits * - * $Date: 27. January 2017 - * $Revision: V.1.5.1 + * $Date: 18. March 2019 + * $Revision: V1.6.0 * * Target Processor: Cortex-M cores * -------------------------------------------------------------------- */ /* - * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved. + * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved. * * SPDX-License-Identifier: Apache-2.0 * @@ -29,163 +29,153 @@ #include "arm_math.h" /** - * @ingroup groupMath + @ingroup groupMath */ /** - * @defgroup shift Vector Shift - * - * Shifts the elements of a fixed-point vector by a specified number of bits. - * There are separate functions for Q7, Q15, and Q31 data types. - * The underlying algorithm used is: - * - * <pre> - * pDst[n] = pSrc[n] << shift, 0 <= n < blockSize. - * </pre> - * - * If <code>shift</code> is positive then the elements of the vector are shifted to the left. - * If <code>shift</code> is negative then the elements of the vector are shifted to the right. - * - * The functions support in-place computation allowing the source and destination - * pointers to reference the same memory buffer. + @defgroup BasicShift Vector Shift + + Shifts the elements of a fixed-point vector by a specified number of bits. + There are separate functions for Q7, Q15, and Q31 data types. + The underlying algorithm used is: + + <pre> + pDst[n] = pSrc[n] << shift, 0 <= n < blockSize. + </pre> + + If <code>shift</code> is positive then the elements of the vector are shifted to the left. + If <code>shift</code> is negative then the elements of the vector are shifted to the right. + + The functions support in-place computation allowing the source and destination + pointers to reference the same memory buffer. */ /** - * @addtogroup shift - * @{ + @addtogroup BasicShift + @{ */ /** - * @brief Shifts the elements of a Q31 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 Q31 range [0x80000000 0x7FFFFFFF] will be saturated. + @brief Shifts the elements of a Q31 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 + + @par Scaling and Overflow Behavior + The function uses saturating arithmetic. + Results outside of the allowable Q31 range [0x80000000 0x7FFFFFFF] are saturated. */ void arm_shift_q31( - q31_t * pSrc, - int8_t shiftBits, - q31_t * pDst, - uint32_t blockSize) + const q31_t * pSrc, + int8_t shiftBits, + q31_t * pDst, + uint32_t blockSize) { - uint32_t blkCnt; /* loop counter */ - uint8_t sign = (shiftBits & 0x80); /* Sign of shiftBits */ + uint32_t blkCnt; /* Loop counter */ + uint8_t sign = (shiftBits & 0x80); /* Sign of shiftBits */ -#if defined (ARM_MATH_DSP) +#if defined (ARM_MATH_LOOPUNROLL) - q31_t in1, in2, in3, in4; /* Temporary input variables */ - q31_t out1, out2, out3, out4; /* Temporary output variables */ + q31_t in, out; /* Temporary variables */ - /*loop Unrolling */ + /* Loop unrolling: Compute 4 outputs at a time */ blkCnt = blockSize >> 2U; - + /* 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) { - /* C = A << shiftBits */ - /* Shift the input and then store the results in the destination buffer. */ - in1 = *pSrc; - in2 = *(pSrc + 1); - out1 = in1 << shiftBits; - in3 = *(pSrc + 2); - out2 = in2 << shiftBits; - in4 = *(pSrc + 3); - if (in1 != (out1 >> shiftBits)) - out1 = 0x7FFFFFFF ^ (in1 >> 31); - - if (in2 != (out2 >> shiftBits)) - out2 = 0x7FFFFFFF ^ (in2 >> 31); - - *pDst = out1; - out3 = in3 << shiftBits; - *(pDst + 1) = out2; - out4 = in4 << shiftBits; - - if (in3 != (out3 >> shiftBits)) - out3 = 0x7FFFFFFF ^ (in3 >> 31); - - if (in4 != (out4 >> shiftBits)) - out4 = 0x7FFFFFFF ^ (in4 >> 31); - - *(pDst + 2) = out3; - *(pDst + 3) = out4; - - /* Update destination pointer to process next sampels */ - pSrc += 4U; - pDst += 4U; - - /* Decrement the loop counter */ + /* C = A << shiftBits */ + + /* Shift input and store result in destination buffer. */ + in = *pSrc++; + out = in << shiftBits; + if (in != (out >> shiftBits)) + out = 0x7FFFFFFF ^ (in >> 31); + *pDst++ = out; + + in = *pSrc++; + out = in << shiftBits; + if (in != (out >> shiftBits)) + out = 0x7FFFFFFF ^ (in >> 31); + *pDst++ = out; + + in = *pSrc++; + out = in << shiftBits; + if (in != (out >> shiftBits)) + out = 0x7FFFFFFF ^ (in >> 31); + *pDst++ = out; + + in = *pSrc++; + out = in << shiftBits; + if (in != (out >> shiftBits)) + out = 0x7FFFFFFF ^ (in >> 31); + *pDst++ = out; + + /* Decrement 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) { - /* C = A >> shiftBits */ - /* Shift the input and then store the results in the destination buffer. */ - in1 = *pSrc; - in2 = *(pSrc + 1); - in3 = *(pSrc + 2); - in4 = *(pSrc + 3); + /* C = A >> shiftBits */ - *pDst = (in1 >> -shiftBits); - *(pDst + 1) = (in2 >> -shiftBits); - *(pDst + 2) = (in3 >> -shiftBits); - *(pDst + 3) = (in4 >> -shiftBits); - - - pSrc += 4U; - pDst += 4U; + /* Shift input and store results in destination buffer. */ + *pDst++ = (*pSrc++ >> -shiftBits); + *pDst++ = (*pSrc++ >> -shiftBits); + *pDst++ = (*pSrc++ >> -shiftBits); + *pDst++ = (*pSrc++ >> -shiftBits); + /* Decrement loop counter */ blkCnt--; } - } - /* If the blockSize is not a multiple of 4, compute any remaining output samples here. - ** No loop unrolling is used. */ + /* Loop unrolling: Compute remaining outputs */ 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) */ - +#endif /* #if defined (ARM_MATH_LOOPUNROLL) */ - while (blkCnt > 0U) + /* If the shift value is positive then do right shift else left shift */ + if (sign == 0U) { - /* C = A (>> or <<) shiftBits */ - /* Shift the input and then store the result in the destination buffer. */ - *pDst++ = (sign == 0U) ? clip_q63_to_q31((q63_t) * pSrc++ << shiftBits) : - (*pSrc++ >> -shiftBits); + while (blkCnt > 0U) + { + /* C = A << shiftBits */ + + /* Shift input and store result in destination buffer. */ + *pDst++ = clip_q63_to_q31((q63_t) *pSrc++ << shiftBits); - /* Decrement the loop counter */ - blkCnt--; + /* Decrement loop counter */ + blkCnt--; + } } + else + { + while (blkCnt > 0U) + { + /* C = A >> shiftBits */ + /* Shift input and store result in destination buffer. */ + *pDst++ = (*pSrc++ >> -shiftBits); + + /* Decrement loop counter */ + blkCnt--; + } + } } /** - * @} end of shift group + @} end of BasicShift group */ |