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/* ----------------------------------------------------------------------
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* Copyright (C) 2010 ARM Limited. All rights reserved.
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*
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* $Date: 15. July 2011
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* $Revision: V1.0.10
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*
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* Project: CMSIS DSP Library
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* Title: arm_conv_partial_fast_q31.c
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*
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* Description: Fast Q31 Partial convolution.
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*
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* Target Processor: Cortex-M4/Cortex-M3
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*
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* Version 1.0.10 2011/7/15
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* Big Endian support added and Merged M0 and M3/M4 Source code.
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*
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* Version 1.0.3 2010/11/29
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* Re-organized the CMSIS folders and updated documentation.
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*
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* Version 1.0.2 2010/11/11
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* Documentation updated.
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*
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* Version 1.0.1 2010/10/05
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* Production release and review comments incorporated.
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*
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* Version 1.0.0 2010/09/20
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* Production release and review comments incorporated.
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* -------------------------------------------------------------------- */
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#include "arm_math.h"
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/**
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* @ingroup groupFilters
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*/
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/**
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* @addtogroup PartialConv
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* @{
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*/
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/**
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* @brief Partial convolution of Q31 sequences (fast version) for Cortex-M3 and Cortex-M4.
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* @param[in] *pSrcA points to the first input sequence.
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* @param[in] srcALen length of the first input sequence.
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* @param[in] *pSrcB points to the second input sequence.
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* @param[in] srcBLen length of the second input sequence.
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* @param[out] *pDst points to the location where the output result is written.
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* @param[in] firstIndex is the first output sample to start with.
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* @param[in] numPoints is the number of output points to be computed.
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* @return Returns either ARM_MATH_SUCCESS if the function completed correctly or ARM_MATH_ARGUMENT_ERROR if the requested subset is not in the range [0 srcALen+srcBLen-2].
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*
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* \par
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* See <code>arm_conv_partial_q31()</code> for a slower implementation of this function which uses a 64-bit accumulator to provide higher precision.
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*/
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arm_status arm_conv_partial_fast_q31(
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q31_t * pSrcA,
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uint32_t srcALen,
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q31_t * pSrcB,
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uint32_t srcBLen,
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q31_t * pDst,
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uint32_t firstIndex,
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uint32_t numPoints)
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{
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q31_t *pIn1; /* inputA pointer */
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q31_t *pIn2; /* inputB pointer */
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q31_t *pOut = pDst; /* output pointer */
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q31_t *px; /* Intermediate inputA pointer */
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q31_t *py; /* Intermediate inputB pointer */
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q31_t *pSrc1, *pSrc2; /* Intermediate pointers */
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q31_t sum, acc0, acc1, acc2, acc3; /* Accumulators */
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q31_t x0, x1, x2, x3, c0;
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uint32_t j, k, count, check, blkCnt;
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int32_t blockSize1, blockSize2, blockSize3; /* loop counters */
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arm_status status; /* status of Partial convolution */
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/* Check for range of output samples to be calculated */
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if((firstIndex + numPoints) > ((srcALen + (srcBLen - 1u))))
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{
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/* Set status as ARM_MATH_ARGUMENT_ERROR */
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status = ARM_MATH_ARGUMENT_ERROR;
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}
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else
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{
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/* The algorithm implementation is based on the lengths of the inputs. */
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/* srcB is always made to slide across srcA. */
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/* So srcBLen is always considered as shorter or equal to srcALen */
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if(srcALen >= srcBLen)
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{
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/* Initialization of inputA pointer */
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pIn1 = pSrcA;
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/* Initialization of inputB pointer */
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pIn2 = pSrcB;
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}
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else
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{
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/* Initialization of inputA pointer */
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pIn1 = pSrcB;
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/* Initialization of inputB pointer */
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pIn2 = pSrcA;
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/* srcBLen is always considered as shorter or equal to srcALen */
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j = srcBLen;
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srcBLen = srcALen;
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srcALen = j;
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}
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/* Conditions to check which loopCounter holds
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* the first and last indices of the output samples to be calculated. */
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check = firstIndex + numPoints;
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blockSize3 = ((int32_t) check - (int32_t) srcALen);
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blockSize3 = (blockSize3 > 0) ? blockSize3 : 0;
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blockSize1 = (((int32_t) srcBLen - 1) - (int32_t) firstIndex);
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blockSize1 = (blockSize1 > 0) ? ((check > (srcBLen - 1u)) ? blockSize1 :
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(int32_t) numPoints) : 0;
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blockSize2 = (int32_t) check - ((blockSize3 + blockSize1) +
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(int32_t) firstIndex);
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blockSize2 = (blockSize2 > 0) ? blockSize2 : 0;
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/* conv(x,y) at n = x[n] * y[0] + x[n-1] * y[1] + x[n-2] * y[2] + ...+ x[n-N+1] * y[N -1] */
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/* The function is internally
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* divided into three stages according to the number of multiplications that has to be
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* taken place between inputA samples and inputB samples. In the first stage of the
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* algorithm, the multiplications increase by one for every iteration.
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* In the second stage of the algorithm, srcBLen number of multiplications are done.
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* In the third stage of the algorithm, the multiplications decrease by one
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* for every iteration. */
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/* Set the output pointer to point to the firstIndex
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* of the output sample to be calculated. */
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pOut = pDst + firstIndex;
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/* --------------------------
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* Initializations of stage1
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* -------------------------*/
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/* sum = x[0] * y[0]
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* sum = x[0] * y[1] + x[1] * y[0]
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* ....
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* sum = x[0] * y[srcBlen - 1] + x[1] * y[srcBlen - 2] +...+ x[srcBLen - 1] * y[0]
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*/
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/* In this stage the MAC operations are increased by 1 for every iteration.
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The count variable holds the number of MAC operations performed.
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Since the partial convolution starts from firstIndex
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Number of Macs to be performed is firstIndex + 1 */
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count = 1u + firstIndex;
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/* Working pointer of inputA */
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px = pIn1;
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/* Working pointer of inputB */
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pSrc2 = pIn2 + firstIndex;
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py = pSrc2;
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/* ------------------------
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* Stage1 process
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* ----------------------*/
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/* The first loop starts here */
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while(blockSize1 > 0)
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{
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/* Accumulator is made zero for every iteration */
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sum = 0;
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/* Apply loop unrolling and compute 4 MACs simultaneously. */
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k = count >> 2u;
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/* First part of the processing with loop unrolling. Compute 4 MACs at a time.
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** a second loop below computes MACs for the remaining 1 to 3 samples. */
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while(k > 0u)
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{
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/* x[0] * y[srcBLen - 1] */
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sum = (q31_t) ((((q63_t) sum << 32) +
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((q63_t) * px++ * (*py--))) >> 32);
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/* x[1] * y[srcBLen - 2] */
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sum = (q31_t) ((((q63_t) sum << 32) +
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((q63_t) * px++ * (*py--))) >> 32);
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/* x[2] * y[srcBLen - 3] */
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sum = (q31_t) ((((q63_t) sum << 32) +
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((q63_t) * px++ * (*py--))) >> 32);
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/* x[3] * y[srcBLen - 4] */
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sum = (q31_t) ((((q63_t) sum << 32) +
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((q63_t) * px++ * (*py--))) >> 32);
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/* Decrement the loop counter */
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k--;
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}
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/* If the count is not a multiple of 4, compute any remaining MACs here.
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** No loop unrolling is used. */
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k = count % 0x4u;
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while(k > 0u)
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{
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/* Perform the multiply-accumulates */
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sum = (q31_t) ((((q63_t) sum << 32) +
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((q63_t) * px++ * (*py--))) >> 32);
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/* Decrement the loop counter */
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k--;
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}
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/* Store the result in the accumulator in the destination buffer. */
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*pOut++ = sum << 1;
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/* Update the inputA and inputB pointers for next MAC calculation */
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py = ++pSrc2;
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px = pIn1;
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/* Increment the MAC count */
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count++;
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/* Decrement the loop counter */
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blockSize1--;
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}
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/* --------------------------
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* Initializations of stage2
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* ------------------------*/
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/* sum = x[0] * y[srcBLen-1] + x[1] * y[srcBLen-2] +...+ x[srcBLen-1] * y[0]
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* sum = x[1] * y[srcBLen-1] + x[2] * y[srcBLen-2] +...+ x[srcBLen] * y[0]
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* ....
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* sum = x[srcALen-srcBLen-2] * y[srcBLen-1] + x[srcALen] * y[srcBLen-2] +...+ x[srcALen-1] * y[0]
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*/
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/* Working pointer of inputA */
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px = pIn1;
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/* Working pointer of inputB */
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pSrc2 = pIn2 + (srcBLen - 1u);
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py = pSrc2;
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/* count is index by which the pointer pIn1 to be incremented */
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count = 1u;
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/* -------------------
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* Stage2 process
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* ------------------*/
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/* Stage2 depends on srcBLen as in this stage srcBLen number of MACS are performed.
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* So, to loop unroll over blockSize2,
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* srcBLen should be greater than or equal to 4 */
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if(srcBLen >= 4u)
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{
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/* Loop unroll over blockSize2 */
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blkCnt = ((uint32_t) blockSize2 >> 2u);
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while(blkCnt > 0u)
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{
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/* Set all accumulators to zero */
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acc0 = 0;
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acc1 = 0;
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acc2 = 0;
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acc3 = 0;
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/* read x[0], x[1], x[2] samples */
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x0 = *(px++);
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x1 = *(px++);
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x2 = *(px++);
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/* Apply loop unrolling and compute 4 MACs simultaneously. */
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k = srcBLen >> 2u;
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/* First part of the processing with loop unrolling. Compute 4 MACs at a time.
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** a second loop below computes MACs for the remaining 1 to 3 samples. */
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do
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{
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/* Read y[srcBLen - 1] sample */
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c0 = *(py--);
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/* Read x[3] sample */
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x3 = *(px++);
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/* Perform the multiply-accumulate */
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/* acc0 += x[0] * y[srcBLen - 1] */
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acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x0 * c0)) >> 32);
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/* acc1 += x[1] * y[srcBLen - 1] */
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acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x1 * c0)) >> 32);
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/* acc2 += x[2] * y[srcBLen - 1] */
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acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x2 * c0)) >> 32);
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/* acc3 += x[3] * y[srcBLen - 1] */
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acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x3 * c0)) >> 32);
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/* Read y[srcBLen - 2] sample */
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c0 = *(py--);
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/* Read x[4] sample */
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x0 = *(px++);
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/* Perform the multiply-accumulate */
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/* acc0 += x[1] * y[srcBLen - 2] */
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acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x1 * c0)) >> 32);
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/* acc1 += x[2] * y[srcBLen - 2] */
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acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x2 * c0)) >> 32);
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/* acc2 += x[3] * y[srcBLen - 2] */
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acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x3 * c0)) >> 32);
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/* acc3 += x[4] * y[srcBLen - 2] */
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acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x0 * c0)) >> 32);
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/* Read y[srcBLen - 3] sample */
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c0 = *(py--);
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/* Read x[5] sample */
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x1 = *(px++);
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/* Perform the multiply-accumulates */
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/* acc0 += x[2] * y[srcBLen - 3] */
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acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x2 * c0)) >> 32);
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/* acc1 += x[3] * y[srcBLen - 2] */
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acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x3 * c0)) >> 32);
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/* acc2 += x[4] * y[srcBLen - 2] */
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acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x0 * c0)) >> 32);
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/* acc3 += x[5] * y[srcBLen - 2] */
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acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x1 * c0)) >> 32);
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/* Read y[srcBLen - 4] sample */
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c0 = *(py--);
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/* Read x[6] sample */
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x2 = *(px++);
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/* Perform the multiply-accumulates */
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/* acc0 += x[3] * y[srcBLen - 4] */
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acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x3 * c0)) >> 32);
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/* acc1 += x[4] * y[srcBLen - 4] */
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acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x0 * c0)) >> 32);
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/* acc2 += x[5] * y[srcBLen - 4] */
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acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x1 * c0)) >> 32);
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/* acc3 += x[6] * y[srcBLen - 4] */
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acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x2 * c0)) >> 32);
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} while(--k);
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/* If the srcBLen is not a multiple of 4, compute any remaining MACs here.
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** No loop unrolling is used. */
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k = srcBLen % 0x4u;
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while(k > 0u)
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{
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/* Read y[srcBLen - 5] sample */
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c0 = *(py--);
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/* Read x[7] sample */
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x3 = *(px++);
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/* Perform the multiply-accumulates */
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/* acc0 += x[4] * y[srcBLen - 5] */
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acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x0 * c0)) >> 32);
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/* acc1 += x[5] * y[srcBLen - 5] */
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acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x1 * c0)) >> 32);
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/* acc2 += x[6] * y[srcBLen - 5] */
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acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x2 * c0)) >> 32);
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/* acc3 += x[7] * y[srcBLen - 5] */
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acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x3 * c0)) >> 32);
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/* Reuse the present samples for the next MAC */
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x0 = x1;
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x1 = x2;
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x2 = x3;
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/* Decrement the loop counter */
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k--;
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}
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/* Store the result in the accumulator in the destination buffer. */
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*pOut++ = (q31_t) (acc0 << 1);
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*pOut++ = (q31_t) (acc1 << 1);
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*pOut++ = (q31_t) (acc2 << 1);
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*pOut++ = (q31_t) (acc3 << 1);
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/* Update the inputA and inputB pointers for next MAC calculation */
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px = pIn1 + (count * 4u);
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py = pSrc2;
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/* Increment the pointer pIn1 index, count by 1 */
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count++;
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/* Decrement the loop counter */
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blkCnt--;
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}
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|
|
|
|
|
/* If the blockSize2 is not a multiple of 4, compute any remaining output samples here.
|
|
|
** No loop unrolling is used. */
|
|
|
blkCnt = (uint32_t) blockSize2 % 0x4u;
|
|
|
|
|
|
while(blkCnt > 0u)
|
|
|
{
|
|
|
/* Accumulator is made zero for every iteration */
|
|
|
sum = 0;
|
|
|
|
|
|
/* Apply loop unrolling and compute 4 MACs simultaneously. */
|
|
|
k = srcBLen >> 2u;
|
|
|
|
|
|
/* First part of the processing with loop unrolling. Compute 4 MACs at a time.
|
|
|
** a second loop below computes MACs for the remaining 1 to 3 samples. */
|
|
|
while(k > 0u)
|
|
|
{
|
|
|
/* Perform the multiply-accumulates */
|
|
|
sum = (q31_t) ((((q63_t) sum << 32) +
|
|
|
((q63_t) * px++ * (*py--))) >> 32);
|
|
|
sum = (q31_t) ((((q63_t) sum << 32) +
|
|
|
((q63_t) * px++ * (*py--))) >> 32);
|
|
|
sum = (q31_t) ((((q63_t) sum << 32) +
|
|
|
((q63_t) * px++ * (*py--))) >> 32);
|
|
|
sum = (q31_t) ((((q63_t) sum << 32) +
|
|
|
((q63_t) * px++ * (*py--))) >> 32);
|
|
|
|
|
|
/* Decrement the loop counter */
|
|
|
k--;
|
|
|
}
|
|
|
|
|
|
/* If the srcBLen is not a multiple of 4, compute any remaining MACs here.
|
|
|
** No loop unrolling is used. */
|
|
|
k = srcBLen % 0x4u;
|
|
|
|
|
|
while(k > 0u)
|
|
|
{
|
|
|
/* Perform the multiply-accumulate */
|
|
|
sum = (q31_t) ((((q63_t) sum << 32) +
|
|
|
((q63_t) * px++ * (*py--))) >> 32);
|
|
|
|
|
|
/* Decrement the loop counter */
|
|
|
k--;
|
|
|
}
|
|
|
|
|
|
/* Store the result in the accumulator in the destination buffer. */
|
|
|
*pOut++ = sum << 1;
|
|
|
|
|
|
/* Update the inputA and inputB pointers for next MAC calculation */
|
|
|
px = pIn1 + count;
|
|
|
py = pSrc2;
|
|
|
|
|
|
/* Increment the MAC count */
|
|
|
count++;
|
|
|
|
|
|
/* Decrement the loop counter */
|
|
|
blkCnt--;
|
|
|
}
|
|
|
}
|
|
|
else
|
|
|
{
|
|
|
/* If the srcBLen is not a multiple of 4,
|
|
|
* the blockSize2 loop cannot be unrolled by 4 */
|
|
|
blkCnt = (uint32_t) blockSize2;
|
|
|
|
|
|
while(blkCnt > 0u)
|
|
|
{
|
|
|
/* Accumulator is made zero for every iteration */
|
|
|
sum = 0;
|
|
|
|
|
|
/* srcBLen number of MACS should be performed */
|
|
|
k = srcBLen;
|
|
|
|
|
|
while(k > 0u)
|
|
|
{
|
|
|
/* Perform the multiply-accumulate */
|
|
|
sum = (q31_t) ((((q63_t) sum << 32) +
|
|
|
((q63_t) * px++ * (*py--))) >> 32);
|
|
|
|
|
|
/* Decrement the loop counter */
|
|
|
k--;
|
|
|
}
|
|
|
|
|
|
/* Store the result in the accumulator in the destination buffer. */
|
|
|
*pOut++ = sum << 1;
|
|
|
|
|
|
/* Update the inputA and inputB pointers for next MAC calculation */
|
|
|
px = pIn1 + count;
|
|
|
py = pSrc2;
|
|
|
|
|
|
/* Increment the MAC count */
|
|
|
count++;
|
|
|
|
|
|
/* Decrement the loop counter */
|
|
|
blkCnt--;
|
|
|
}
|
|
|
}
|
|
|
|
|
|
|
|
|
/* --------------------------
|
|
|
* Initializations of stage3
|
|
|
* -------------------------*/
|
|
|
|
|
|
/* sum += x[srcALen-srcBLen+1] * y[srcBLen-1] + x[srcALen-srcBLen+2] * y[srcBLen-2] +...+ x[srcALen-1] * y[1]
|
|
|
* sum += x[srcALen-srcBLen+2] * y[srcBLen-1] + x[srcALen-srcBLen+3] * y[srcBLen-2] +...+ x[srcALen-1] * y[2]
|
|
|
* ....
|
|
|
* sum += x[srcALen-2] * y[srcBLen-1] + x[srcALen-1] * y[srcBLen-2]
|
|
|
* sum += x[srcALen-1] * y[srcBLen-1]
|
|
|
*/
|
|
|
|
|
|
/* In this stage the MAC operations are decreased by 1 for every iteration.
|
|
|
The count variable holds the number of MAC operations performed */
|
|
|
count = srcBLen - 1u;
|
|
|
|
|
|
/* Working pointer of inputA */
|
|
|
pSrc1 = (pIn1 + srcALen) - (srcBLen - 1u);
|
|
|
px = pSrc1;
|
|
|
|
|
|
/* Working pointer of inputB */
|
|
|
pSrc2 = pIn2 + (srcBLen - 1u);
|
|
|
py = pSrc2;
|
|
|
|
|
|
/* -------------------
|
|
|
* Stage3 process
|
|
|
* ------------------*/
|
|
|
|
|
|
while(blockSize3 > 0)
|
|
|
{
|
|
|
/* Accumulator is made zero for every iteration */
|
|
|
sum = 0;
|
|
|
|
|
|
/* Apply loop unrolling and compute 4 MACs simultaneously. */
|
|
|
k = count >> 2u;
|
|
|
|
|
|
/* First part of the processing with loop unrolling. Compute 4 MACs at a time.
|
|
|
** a second loop below computes MACs for the remaining 1 to 3 samples. */
|
|
|
while(k > 0u)
|
|
|
{
|
|
|
/* sum += x[srcALen - srcBLen + 1] * y[srcBLen - 1] */
|
|
|
sum = (q31_t) ((((q63_t) sum << 32) +
|
|
|
((q63_t) * px++ * (*py--))) >> 32);
|
|
|
|
|
|
/* sum += x[srcALen - srcBLen + 2] * y[srcBLen - 2] */
|
|
|
sum = (q31_t) ((((q63_t) sum << 32) +
|
|
|
((q63_t) * px++ * (*py--))) >> 32);
|
|
|
|
|
|
/* sum += x[srcALen - srcBLen + 3] * y[srcBLen - 3] */
|
|
|
sum = (q31_t) ((((q63_t) sum << 32) +
|
|
|
((q63_t) * px++ * (*py--))) >> 32);
|
|
|
|
|
|
/* sum += x[srcALen - srcBLen + 4] * y[srcBLen - 4] */
|
|
|
sum = (q31_t) ((((q63_t) sum << 32) +
|
|
|
((q63_t) * px++ * (*py--))) >> 32);
|
|
|
|
|
|
/* Decrement the loop counter */
|
|
|
k--;
|
|
|
}
|
|
|
|
|
|
/* If the count is not a multiple of 4, compute any remaining MACs here.
|
|
|
** No loop unrolling is used. */
|
|
|
k = count % 0x4u;
|
|
|
|
|
|
while(k > 0u)
|
|
|
{
|
|
|
/* Perform the multiply-accumulates */
|
|
|
/* sum += x[srcALen-1] * y[srcBLen-1] */
|
|
|
sum = (q31_t) ((((q63_t) sum << 32) +
|
|
|
((q63_t) * px++ * (*py--))) >> 32);
|
|
|
|
|
|
/* Decrement the loop counter */
|
|
|
k--;
|
|
|
}
|
|
|
|
|
|
/* Store the result in the accumulator in the destination buffer. */
|
|
|
*pOut++ = sum << 1;
|
|
|
|
|
|
/* Update the inputA and inputB pointers for next MAC calculation */
|
|
|
px = ++pSrc1;
|
|
|
py = pSrc2;
|
|
|
|
|
|
/* Decrement the MAC count */
|
|
|
count--;
|
|
|
|
|
|
/* Decrement the loop counter */
|
|
|
blockSize3--;
|
|
|
|
|
|
}
|
|
|
|
|
|
/* set status as ARM_MATH_SUCCESS */
|
|
|
status = ARM_MATH_SUCCESS;
|
|
|
}
|
|
|
|
|
|
/* Return to application */
|
|
|
return (status);
|
|
|
|
|
|
}
|
|
|
|
|
|
/**
|
|
|
* @} end of PartialConv group
|
|
|
*/
|
|
|
|