148 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			148 lines
		
	
	
		
			4.1 KiB
		
	
	
	
		
			C
		
	
	
	
/* ----------------------------------------------------------------------
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 * Project:      CMSIS DSP Library
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 * Title:        arm_dot_prod_q7.c
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 * Description:  Q7 dot product
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 *
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 * $Date:        27. January 2017
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 * $Revision:    V.1.5.1
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 *
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 * Target Processor: Cortex-M cores
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 * -------------------------------------------------------------------- */
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/*
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 * Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
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 *
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 * SPDX-License-Identifier: Apache-2.0
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 *
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 * Licensed under the Apache License, Version 2.0 (the License); you may
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 * not use this file except in compliance with the License.
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 * You may obtain a copy of the License at
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 *
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 * www.apache.org/licenses/LICENSE-2.0
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 *
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 * Unless required by applicable law or agreed to in writing, software
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 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
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 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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 * See the License for the specific language governing permissions and
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 * limitations under the License.
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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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#if defined (ARM_MATH_DSP)
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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 /* #if defined (ARM_MATH_DSP) */
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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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