/* ----------------------------------------------------------------------
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* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
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*
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* $Date: 19. March 2015
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* $Revision: V.1.4.5
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*
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* Project: CMSIS DSP Library
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* Title: arm_dot_prod_q7.c
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*
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* Description: Q7 dot product.
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*
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* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* - Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* - Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* - Neither the name of ARM LIMITED nor the names of its contributors
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* may be used to endorse or promote products derived from this
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* software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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* -------------------------------------------------------------------- */
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#include "arm_math.h"
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/**
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* @ingroup groupMath
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*/
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/**
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* @addtogroup dot_prod
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* @{
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*/
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/**
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* @brief Dot product of Q7 vectors.
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* @param[in] *pSrcA points to the first input vector
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* @param[in] *pSrcB points to the second input vector
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* @param[in] blockSize number of samples in each vector
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* @param[out] *result output result returned here
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* @return none.
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*
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* <b>Scaling and Overflow Behavior:</b>
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* \par
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* The intermediate multiplications are in 1.7 x 1.7 = 2.14 format and these
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* results are added to an accumulator in 18.14 format.
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* Nonsaturating additions are used and there is no danger of wrap around as long as
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* the vectors are less than 2^18 elements long.
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* The return result is in 18.14 format.
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*/
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void arm_dot_prod_q7(
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q7_t * pSrcA,
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q7_t * pSrcB,
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uint32_t blockSize,
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q31_t * result)
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{
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uint32_t blkCnt; /* loop counter */
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q31_t sum = 0; /* Temporary variables to store output */
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#ifndef ARM_MATH_CM0_FAMILY
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/* Run the below code for Cortex-M4 and Cortex-M3 */
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q31_t input1, input2; /* Temporary variables to store input */
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q31_t inA1, inA2, inB1, inB2; /* Temporary variables to store input */
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/*loop Unrolling */
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blkCnt = blockSize >> 2u;
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/* First part of the processing with loop unrolling. Compute 4 outputs at a time.
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** a second loop below computes the remaining 1 to 3 samples. */
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while(blkCnt > 0u)
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{
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/* read 4 samples at a time from sourceA */
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input1 = *__SIMD32(pSrcA)++;
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/* read 4 samples at a time from sourceB */
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input2 = *__SIMD32(pSrcB)++;
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/* extract two q7_t samples to q15_t samples */
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inA1 = __SXTB16(__ROR(input1, 8));
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/* extract reminaing two samples */
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inA2 = __SXTB16(input1);
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/* extract two q7_t samples to q15_t samples */
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inB1 = __SXTB16(__ROR(input2, 8));
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/* extract reminaing two samples */
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inB2 = __SXTB16(input2);
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/* multiply and accumulate two samples at a time */
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sum = __SMLAD(inA1, inB1, sum);
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sum = __SMLAD(inA2, inB2, sum);
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/* Decrement the loop counter */
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blkCnt--;
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}
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/* If the blockSize is not a multiple of 4, compute any remaining output samples here.
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** No loop unrolling is used. */
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blkCnt = blockSize % 0x4u;
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while(blkCnt > 0u)
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{
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/* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
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/* Dot product and then store the results in a temporary buffer. */
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sum = __SMLAD(*pSrcA++, *pSrcB++, sum);
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/* Decrement the loop counter */
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blkCnt--;
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}
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#else
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/* Run the below code for Cortex-M0 */
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/* Initialize blkCnt with number of samples */
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blkCnt = blockSize;
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while(blkCnt > 0u)
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{
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/* C = A[0]* B[0] + A[1]* B[1] + A[2]* B[2] + .....+ A[blockSize-1]* B[blockSize-1] */
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/* Dot product and then store the results in a temporary buffer. */
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sum += (q31_t) ((q15_t) * pSrcA++ * *pSrcB++);
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/* Decrement the loop counter */
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blkCnt--;
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}
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#endif /* #ifndef ARM_MATH_CM0_FAMILY */
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/* Store the result in the destination buffer in 18.14 format */
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*result = sum;
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}
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/**
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* @} end of dot_prod group
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*/
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