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author | rihab kouki <rihab.kouki@st.com> | 2020-07-28 11:24:49 +0100 |
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committer | rihab kouki <rihab.kouki@st.com> | 2020-07-28 11:24:49 +0100 |
commit | 96d6da4e252b06dcfdc041e7df23e86161c33007 (patch) | |
tree | a262f59bb1db7ec7819acae435f5049cbe5e2354 /DSP/Source/BasicMathFunctions/arm_sub_q15.c | |
parent | 9f95ff5b6ba01db09552b84a0ab79607060a2666 (diff) | |
download | st-cmsis-core-lowfat-master.tar.gz st-cmsis-core-lowfat-master.tar.bz2 st-cmsis-core-lowfat-master.zip |
Diffstat (limited to 'DSP/Source/BasicMathFunctions/arm_sub_q15.c')
-rw-r--r-- | DSP/Source/BasicMathFunctions/arm_sub_q15.c | 110 |
1 files changed, 54 insertions, 56 deletions
diff --git a/DSP/Source/BasicMathFunctions/arm_sub_q15.c b/DSP/Source/BasicMathFunctions/arm_sub_q15.c index 17942eb..835917e 100644 --- a/DSP/Source/BasicMathFunctions/arm_sub_q15.c +++ b/DSP/Source/BasicMathFunctions/arm_sub_q15.c @@ -3,13 +3,13 @@ * Title: arm_sub_q15.c * Description: Q15 vector subtraction * - * $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 * @@ -29,100 +29,98 @@ #include "arm_math.h" /** - * @ingroup groupMath + @ingroup groupMath */ /** - * @addtogroup BasicSub - * @{ + @addtogroup BasicSub + @{ */ /** - * @brief Q15 vector subtraction. - * @param[in] *pSrcA points to the first input vector - * @param[in] *pSrcB points to the second input vector - * @param[out] *pDst points to the output vector - * @param[in] blockSize number of samples in each 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. + @brief Q15 vector subtraction. + @param[in] pSrcA points to the first input vector + @param[in] pSrcB points to the second input vector + @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 function uses saturating arithmetic. + Results outside of the allowable Q15 range [0x8000 0x7FFF] are saturated. */ void arm_sub_q15( - q15_t * pSrcA, - q15_t * pSrcB, - q15_t * pDst, - uint32_t blockSize) + const q15_t * pSrcA, + const q15_t * pSrcB, + q15_t * pDst, + uint32_t blockSize) { - uint32_t blkCnt; /* loop counter */ + uint32_t blkCnt; /* Loop counter */ +#if defined (ARM_MATH_LOOPUNROLL) #if defined (ARM_MATH_DSP) - -/* Run the below code for Cortex-M4 and Cortex-M3 */ q31_t inA1, inA2; q31_t inB1, inB2; +#endif - /*loop Unrolling */ + /* Loop unrolling: Compute 4 outputs at a time */ 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 - B */ - /* Subtract and then store the results in the destination buffer two samples at a time. */ - inA1 = *__SIMD32(pSrcA)++; - inA2 = *__SIMD32(pSrcA)++; - inB1 = *__SIMD32(pSrcB)++; - inB2 = *__SIMD32(pSrcB)++; - *__SIMD32(pDst)++ = __QSUB16(inA1, inB1); - *__SIMD32(pDst)++ = __QSUB16(inA2, inB2); +#if defined (ARM_MATH_DSP) + /* read 2 times 2 samples at a time from sourceA */ + inA1 = read_q15x2_ia ((q15_t **) &pSrcA); + inA2 = read_q15x2_ia ((q15_t **) &pSrcA); + /* read 2 times 2 samples at a time from sourceB */ + inB1 = read_q15x2_ia ((q15_t **) &pSrcB); + inB2 = read_q15x2_ia ((q15_t **) &pSrcB); + + /* Subtract and store 2 times 2 samples at a time */ + write_q15x2_ia (&pDst, __QSUB16(inA1, inB1)); + write_q15x2_ia (&pDst, __QSUB16(inA2, inB2)); +#else + *pDst++ = (q15_t) __SSAT(((q31_t) *pSrcA++ - *pSrcB++), 16); + *pDst++ = (q15_t) __SSAT(((q31_t) *pSrcA++ - *pSrcB++), 16); + *pDst++ = (q15_t) __SSAT(((q31_t) *pSrcA++ - *pSrcB++), 16); + *pDst++ = (q15_t) __SSAT(((q31_t) *pSrcA++ - *pSrcB++), 16); +#endif - /* Decrement the loop counter */ + /* 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; - while (blkCnt > 0U) - { - /* C = A - B */ - /* Subtract and then store the result in the destination buffer. */ - *pDst++ = (q15_t) __QSUB16(*pSrcA++, *pSrcB++); - - /* Decrement the loop counter */ - blkCnt--; - } - #else - /* Run the below code for Cortex-M0 */ - /* Initialize blkCnt with number of samples */ blkCnt = blockSize; +#endif /* #if defined (ARM_MATH_LOOPUNROLL) */ + while (blkCnt > 0U) { /* C = A - B */ - /* Subtract and then store the result in the destination buffer. */ - *pDst++ = (q15_t) __SSAT(((q31_t) * pSrcA++ - *pSrcB++), 16); - /* Decrement the loop counter */ + /* Subtract and store result in destination buffer. */ +#if defined (ARM_MATH_DSP) + *pDst++ = (q15_t) __QSUB16(*pSrcA++, *pSrcB++); +#else + *pDst++ = (q15_t) __SSAT(((q31_t) *pSrcA++ - *pSrcB++), 16); +#endif + + /* Decrement loop counter */ blkCnt--; } -#endif /* #if defined (ARM_MATH_DSP) */ - - } /** - * @} end of BasicSub group + @} end of BasicSub group */ |