/* ----------------------------------------------------------------------
|
* Project: CMSIS DSP Library
|
* Title: arm_conv_partial_q31.c
|
* Description: Partial convolution of Q31 sequences
|
*
|
* $Date: 27. January 2017
|
* $Revision: V.1.5.1
|
*
|
* Target Processor: Cortex-M cores
|
* -------------------------------------------------------------------- */
|
/*
|
* Copyright (C) 2010-2017 ARM Limited or its affiliates. All rights reserved.
|
*
|
* SPDX-License-Identifier: Apache-2.0
|
*
|
* Licensed under the Apache License, Version 2.0 (the License); you may
|
* not use this file except in compliance with the License.
|
* You may obtain a copy of the License at
|
*
|
* www.apache.org/licenses/LICENSE-2.0
|
*
|
* Unless required by applicable law or agreed to in writing, software
|
* distributed under the License is distributed on an AS IS BASIS, WITHOUT
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
* See the License for the specific language governing permissions and
|
* limitations under the License.
|
*/
|
|
#include "arm_math.h"
|
|
/**
|
* @ingroup groupFilters
|
*/
|
|
/**
|
* @addtogroup PartialConv
|
* @{
|
*/
|
|
/**
|
* @brief Partial convolution of Q31 sequences.
|
* @param[in] *pSrcA points to the first input sequence.
|
* @param[in] srcALen length of the first input sequence.
|
* @param[in] *pSrcB points to the second input sequence.
|
* @param[in] srcBLen length of the second input sequence.
|
* @param[out] *pDst points to the location where the output result is written.
|
* @param[in] firstIndex is the first output sample to start with.
|
* @param[in] numPoints is the number of output points to be computed.
|
* @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].
|
*
|
* See <code>arm_conv_partial_fast_q31()</code> for a faster but less precise implementation of this function for Cortex-M3 and Cortex-M4.
|
*/
|
|
arm_status arm_conv_partial_q31(
|
q31_t * pSrcA,
|
uint32_t srcALen,
|
q31_t * pSrcB,
|
uint32_t srcBLen,
|
q31_t * pDst,
|
uint32_t firstIndex,
|
uint32_t numPoints)
|
{
|
|
|
#if defined (ARM_MATH_DSP)
|
|
/* Run the below code for Cortex-M4 and Cortex-M3 */
|
|
q31_t *pIn1; /* inputA pointer */
|
q31_t *pIn2; /* inputB pointer */
|
q31_t *pOut = pDst; /* output pointer */
|
q31_t *px; /* Intermediate inputA pointer */
|
q31_t *py; /* Intermediate inputB pointer */
|
q31_t *pSrc1, *pSrc2; /* Intermediate pointers */
|
q63_t sum, acc0, acc1, acc2; /* Accumulator */
|
q31_t x0, x1, x2, c0;
|
uint32_t j, k, count, check, blkCnt;
|
int32_t blockSize1, blockSize2, blockSize3; /* loop counter */
|
arm_status status; /* status of Partial convolution */
|
|
|
/* Check for range of output samples to be calculated */
|
if ((firstIndex + numPoints) > ((srcALen + (srcBLen - 1U))))
|
{
|
/* Set status as ARM_MATH_ARGUMENT_ERROR */
|
status = ARM_MATH_ARGUMENT_ERROR;
|
}
|
else
|
{
|
|
/* The algorithm implementation is based on the lengths of the inputs. */
|
/* srcB is always made to slide across srcA. */
|
/* So srcBLen is always considered as shorter or equal to srcALen */
|
if (srcALen >= srcBLen)
|
{
|
/* Initialization of inputA pointer */
|
pIn1 = pSrcA;
|
|
/* Initialization of inputB pointer */
|
pIn2 = pSrcB;
|
}
|
else
|
{
|
/* Initialization of inputA pointer */
|
pIn1 = pSrcB;
|
|
/* Initialization of inputB pointer */
|
pIn2 = pSrcA;
|
|
/* srcBLen is always considered as shorter or equal to srcALen */
|
j = srcBLen;
|
srcBLen = srcALen;
|
srcALen = j;
|
}
|
|
/* Conditions to check which loopCounter holds
|
* the first and last indices of the output samples to be calculated. */
|
check = firstIndex + numPoints;
|
blockSize3 = ((int32_t)check > (int32_t)srcALen) ? (int32_t)check - (int32_t)srcALen : 0;
|
blockSize3 = ((int32_t)firstIndex > (int32_t)srcALen - 1) ? blockSize3 - (int32_t)firstIndex + (int32_t)srcALen : blockSize3;
|
blockSize1 = (((int32_t) srcBLen - 1) - (int32_t) firstIndex);
|
blockSize1 = (blockSize1 > 0) ? ((check > (srcBLen - 1U)) ? blockSize1 :
|
(int32_t) numPoints) : 0;
|
blockSize2 = (int32_t) check - ((blockSize3 + blockSize1) +
|
(int32_t) firstIndex);
|
blockSize2 = (blockSize2 > 0) ? blockSize2 : 0;
|
|
/* 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] */
|
/* The function is internally
|
* divided into three stages according to the number of multiplications that has to be
|
* taken place between inputA samples and inputB samples. In the first stage of the
|
* algorithm, the multiplications increase by one for every iteration.
|
* In the second stage of the algorithm, srcBLen number of multiplications are done.
|
* In the third stage of the algorithm, the multiplications decrease by one
|
* for every iteration. */
|
|
/* Set the output pointer to point to the firstIndex
|
* of the output sample to be calculated. */
|
pOut = pDst + firstIndex;
|
|
/* --------------------------
|
* Initializations of stage1
|
* -------------------------*/
|
|
/* sum = x[0] * y[0]
|
* sum = x[0] * y[1] + x[1] * y[0]
|
* ....
|
* sum = x[0] * y[srcBlen - 1] + x[1] * y[srcBlen - 2] +...+ x[srcBLen - 1] * y[0]
|
*/
|
|
/* In this stage the MAC operations are increased by 1 for every iteration.
|
The count variable holds the number of MAC operations performed.
|
Since the partial convolution starts from firstIndex
|
Number of Macs to be performed is firstIndex + 1 */
|
count = 1U + firstIndex;
|
|
/* Working pointer of inputA */
|
px = pIn1;
|
|
/* Working pointer of inputB */
|
pSrc2 = pIn2 + firstIndex;
|
py = pSrc2;
|
|
/* ------------------------
|
* Stage1 process
|
* ----------------------*/
|
|
/* The first loop starts here */
|
while (blockSize1 > 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)
|
{
|
/* x[0] * y[srcBLen - 1] */
|
sum += (q63_t) * px++ * (*py--);
|
/* x[1] * y[srcBLen - 2] */
|
sum += (q63_t) * px++ * (*py--);
|
/* x[2] * y[srcBLen - 3] */
|
sum += (q63_t) * px++ * (*py--);
|
/* x[3] * y[srcBLen - 4] */
|
sum += (q63_t) * px++ * (*py--);
|
|
/* 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-accumulate */
|
sum += (q63_t) * px++ * (*py--);
|
|
/* Decrement the loop counter */
|
k--;
|
}
|
|
/* Store the result in the accumulator in the destination buffer. */
|
*pOut++ = (q31_t) (sum >> 31);
|
|
/* Update the inputA and inputB pointers for next MAC calculation */
|
py = ++pSrc2;
|
px = pIn1;
|
|
/* Increment the MAC count */
|
count++;
|
|
/* Decrement the loop counter */
|
blockSize1--;
|
}
|
|
/* --------------------------
|
* Initializations of stage2
|
* ------------------------*/
|
|
/* sum = x[0] * y[srcBLen-1] + x[1] * y[srcBLen-2] +...+ x[srcBLen-1] * y[0]
|
* sum = x[1] * y[srcBLen-1] + x[2] * y[srcBLen-2] +...+ x[srcBLen] * y[0]
|
* ....
|
* sum = x[srcALen-srcBLen-2] * y[srcBLen-1] + x[srcALen] * y[srcBLen-2] +...+ x[srcALen-1] * y[0]
|
*/
|
|
/* Working pointer of inputA */
|
if ((int32_t)firstIndex - (int32_t)srcBLen + 1 > 0)
|
{
|
px = pIn1 + firstIndex - srcBLen + 1;
|
}
|
else
|
{
|
px = pIn1;
|
}
|
|
/* Working pointer of inputB */
|
pSrc2 = pIn2 + (srcBLen - 1U);
|
py = pSrc2;
|
|
/* count is index by which the pointer pIn1 to be incremented */
|
count = 0U;
|
|
/* -------------------
|
* Stage2 process
|
* ------------------*/
|
|
/* Stage2 depends on srcBLen as in this stage srcBLen number of MACS are performed.
|
* So, to loop unroll over blockSize2,
|
* srcBLen should be greater than or equal to 4 */
|
if (srcBLen >= 4U)
|
{
|
/* Loop unroll over blkCnt */
|
|
blkCnt = blockSize2 / 3;
|
while (blkCnt > 0U)
|
{
|
/* Set all accumulators to zero */
|
acc0 = 0;
|
acc1 = 0;
|
acc2 = 0;
|
|
/* read x[0], x[1] samples */
|
x0 = *(px++);
|
x1 = *(px++);
|
|
/* Apply loop unrolling and compute 3 MACs simultaneously. */
|
k = srcBLen / 3;
|
|
/* First part of the processing with loop unrolling. Compute 3 MACs at a time.
|
** a second loop below computes MACs for the remaining 1 to 2 samples. */
|
do
|
{
|
/* Read y[srcBLen - 1] sample */
|
c0 = *(py);
|
|
/* Read x[2] sample */
|
x2 = *(px);
|
|
/* Perform the multiply-accumulates */
|
/* acc0 += x[0] * y[srcBLen - 1] */
|
acc0 += (q63_t) x0 *c0;
|
/* acc1 += x[1] * y[srcBLen - 1] */
|
acc1 += (q63_t) x1 *c0;
|
/* acc2 += x[2] * y[srcBLen - 1] */
|
acc2 += (q63_t) x2 *c0;
|
|
/* Read y[srcBLen - 2] sample */
|
c0 = *(py - 1U);
|
|
/* Read x[3] sample */
|
x0 = *(px + 1U);
|
|
/* Perform the multiply-accumulate */
|
/* acc0 += x[1] * y[srcBLen - 2] */
|
acc0 += (q63_t) x1 *c0;
|
/* acc1 += x[2] * y[srcBLen - 2] */
|
acc1 += (q63_t) x2 *c0;
|
/* acc2 += x[3] * y[srcBLen - 2] */
|
acc2 += (q63_t) x0 *c0;
|
|
/* Read y[srcBLen - 3] sample */
|
c0 = *(py - 2U);
|
|
/* Read x[4] sample */
|
x1 = *(px + 2U);
|
|
/* Perform the multiply-accumulates */
|
/* acc0 += x[2] * y[srcBLen - 3] */
|
acc0 += (q63_t) x2 *c0;
|
/* acc1 += x[3] * y[srcBLen - 2] */
|
acc1 += (q63_t) x0 *c0;
|
/* acc2 += x[4] * y[srcBLen - 2] */
|
acc2 += (q63_t) x1 *c0;
|
|
|
px += 3U;
|
|
py -= 3U;
|
|
} while (--k);
|
|
/* If the srcBLen is not a multiple of 3, compute any remaining MACs here.
|
** No loop unrolling is used. */
|
k = srcBLen - (3 * (srcBLen / 3));
|
|
while (k > 0U)
|
{
|
/* Read y[srcBLen - 5] sample */
|
c0 = *(py--);
|
|
/* Read x[7] sample */
|
x2 = *(px++);
|
|
/* Perform the multiply-accumulates */
|
/* acc0 += x[4] * y[srcBLen - 5] */
|
acc0 += (q63_t) x0 *c0;
|
/* acc1 += x[5] * y[srcBLen - 5] */
|
acc1 += (q63_t) x1 *c0;
|
/* acc2 += x[6] * y[srcBLen - 5] */
|
acc2 += (q63_t) x2 *c0;
|
|
/* Reuse the present samples for the next MAC */
|
x0 = x1;
|
x1 = x2;
|
|
/* Decrement the loop counter */
|
k--;
|
}
|
|
/* Store the result in the accumulator in the destination buffer. */
|
*pOut++ = (q31_t) (acc0 >> 31);
|
*pOut++ = (q31_t) (acc1 >> 31);
|
*pOut++ = (q31_t) (acc2 >> 31);
|
|
/* Increment the pointer pIn1 index, count by 3 */
|
count += 3U;
|
|
/* Update the inputA and inputB pointers for next MAC calculation */
|
if ((int32_t)firstIndex - (int32_t)srcBLen + 1 > 0)
|
{
|
px = pIn1 + firstIndex - srcBLen + 1 + count;
|
}
|
else
|
{
|
px = pIn1 + count;
|
}
|
py = pSrc2;
|
|
/* Decrement the loop counter */
|
blkCnt--;
|
}
|
|
/* If the blockSize2 is not a multiple of 3, compute any remaining output samples here.
|
** No loop unrolling is used. */
|
blkCnt = blockSize2 - 3 * (blockSize2 / 3);
|
|
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 += (q63_t) * px++ * (*py--);
|
sum += (q63_t) * px++ * (*py--);
|
sum += (q63_t) * px++ * (*py--);
|
sum += (q63_t) * px++ * (*py--);
|
|
/* 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 += (q63_t) * px++ * (*py--);
|
|
/* Decrement the loop counter */
|
k--;
|
}
|
|
/* Store the result in the accumulator in the destination buffer. */
|
*pOut++ = (q31_t) (sum >> 31);
|
|
/* Increment the MAC count */
|
count++;
|
|
/* Update the inputA and inputB pointers for next MAC calculation */
|
if ((int32_t)firstIndex - (int32_t)srcBLen + 1 > 0)
|
{
|
px = pIn1 + firstIndex - srcBLen + 1 + count;
|
}
|
else
|
{
|
px = pIn1 + count;
|
}
|
py = pSrc2;
|
|
/* 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 += (q63_t) * px++ * (*py--);
|
|
/* Decrement the loop counter */
|
k--;
|
}
|
|
/* Store the result in the accumulator in the destination buffer. */
|
*pOut++ = (q31_t) (sum >> 31);
|
|
/* Increment the MAC count */
|
count++;
|
|
/* Update the inputA and inputB pointers for next MAC calculation */
|
if ((int32_t)firstIndex - (int32_t)srcBLen + 1 > 0)
|
{
|
px = pIn1 + firstIndex - srcBLen + 1 + count;
|
}
|
else
|
{
|
px = pIn1 + count;
|
}
|
py = pSrc2;
|
|
/* 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 blockSize3 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 += (q63_t) * px++ * (*py--);
|
sum += (q63_t) * px++ * (*py--);
|
sum += (q63_t) * px++ * (*py--);
|
sum += (q63_t) * px++ * (*py--);
|
|
/* Decrement the loop counter */
|
k--;
|
}
|
|
/* If the blockSize3 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-accumulate */
|
sum += (q63_t) * px++ * (*py--);
|
|
/* Decrement the loop counter */
|
k--;
|
}
|
|
/* Store the result in the accumulator in the destination buffer. */
|
*pOut++ = (q31_t) (sum >> 31);
|
|
/* 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);
|
|
#else
|
|
/* Run the below code for Cortex-M0 */
|
|
q31_t *pIn1 = pSrcA; /* inputA pointer */
|
q31_t *pIn2 = pSrcB; /* inputB pointer */
|
q63_t sum; /* Accumulator */
|
uint32_t i, j; /* loop counters */
|
arm_status status; /* status of Partial convolution */
|
|
/* Check for range of output samples to be calculated */
|
if ((firstIndex + numPoints) > ((srcALen + (srcBLen - 1U))))
|
{
|
/* Set status as ARM_ARGUMENT_ERROR */
|
status = ARM_MATH_ARGUMENT_ERROR;
|
}
|
else
|
{
|
/* Loop to calculate convolution for output length number of values */
|
for (i = firstIndex; i <= (firstIndex + numPoints - 1); i++)
|
{
|
/* Initialize sum with zero to carry on MAC operations */
|
sum = 0;
|
|
/* Loop to perform MAC operations according to convolution equation */
|
for (j = 0; j <= i; j++)
|
{
|
/* Check the array limitations */
|
if (((i - j) < srcBLen) && (j < srcALen))
|
{
|
/* z[i] += x[i-j] * y[j] */
|
sum += ((q63_t) pIn1[j] * (pIn2[i - j]));
|
}
|
}
|
|
/* Store the output in the destination buffer */
|
pDst[i] = (q31_t) (sum >> 31U);
|
}
|
/* set status as ARM_SUCCESS as there are no argument errors */
|
status = ARM_MATH_SUCCESS;
|
}
|
return (status);
|
|
#endif /* #if defined (ARM_MATH_DSP) */
|
|
}
|
|
/**
|
* @} end of PartialConv group
|
*/
|
