You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
566 lines
18 KiB
C
566 lines
18 KiB
C
/* ----------------------------------------------------------------------
|
|
* Copyright (C) 2010-2014 ARM Limited. All rights reserved.
|
|
*
|
|
* $Date: 19. March 2015
|
|
* $Revision: V.1.4.5
|
|
*
|
|
* Project: CMSIS DSP Library
|
|
* Title: arm_conv_q31.c
|
|
*
|
|
* Description: Convolution of Q31 sequences.
|
|
*
|
|
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* - Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* - Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* - Neither the name of ARM LIMITED nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this
|
|
* software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
|
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
* -------------------------------------------------------------------- */
|
|
|
|
#include "arm_math.h"
|
|
|
|
/**
|
|
* @ingroup groupFilters
|
|
*/
|
|
|
|
/**
|
|
* @addtogroup Conv
|
|
* @{
|
|
*/
|
|
|
|
/**
|
|
* @brief 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. Length srcALen+srcBLen-1.
|
|
* @return none.
|
|
*
|
|
* @details
|
|
* <b>Scaling and Overflow Behavior:</b>
|
|
*
|
|
* \par
|
|
* The function is implemented using an internal 64-bit accumulator.
|
|
* The accumulator has a 2.62 format and maintains full precision of the intermediate multiplication results but provides only a single guard bit.
|
|
* There is no saturation on intermediate additions.
|
|
* Thus, if the accumulator overflows it wraps around and distorts the result.
|
|
* The input signals should be scaled down to avoid intermediate overflows.
|
|
* Scale down the inputs by log2(min(srcALen, srcBLen)) (log2 is read as log to the base 2) times to avoid overflows,
|
|
* as maximum of min(srcALen, srcBLen) number of additions are carried internally.
|
|
* The 2.62 accumulator is right shifted by 31 bits and saturated to 1.31 format to yield the final result.
|
|
*
|
|
* \par
|
|
* See <code>arm_conv_fast_q31()</code> for a faster but less precise implementation of this function for Cortex-M3 and Cortex-M4.
|
|
*/
|
|
|
|
void arm_conv_q31(
|
|
q31_t * pSrcA,
|
|
uint32_t srcALen,
|
|
q31_t * pSrcB,
|
|
uint32_t srcBLen,
|
|
q31_t * pDst)
|
|
{
|
|
|
|
|
|
#ifndef ARM_MATH_CM0_FAMILY
|
|
|
|
/* 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; /* Accumulator */
|
|
q63_t acc0, acc1, acc2; /* Accumulator */
|
|
q31_t x0, x1, x2, c0; /* Temporary variables to hold state and coefficient values */
|
|
uint32_t j, k, count, blkCnt, blockSize1, blockSize2, blockSize3; /* loop counter */
|
|
|
|
/* 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 = (q31_t *) pSrcB;
|
|
|
|
/* Initialization of inputB pointer */
|
|
pIn2 = (q31_t *) pSrcA;
|
|
|
|
/* srcBLen is always considered as shorter or equal to srcALen */
|
|
j = srcBLen;
|
|
srcBLen = srcALen;
|
|
srcALen = j;
|
|
}
|
|
|
|
/* 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. */
|
|
|
|
/* The algorithm is implemented in three stages.
|
|
The loop counters of each stage is initiated here. */
|
|
blockSize1 = srcBLen - 1u;
|
|
blockSize2 = srcALen - (srcBLen - 1u);
|
|
blockSize3 = blockSize1;
|
|
|
|
/* --------------------------
|
|
* 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 */
|
|
count = 1u;
|
|
|
|
/* Working pointer of inputA */
|
|
px = pIn1;
|
|
|
|
/* Working pointer of inputB */
|
|
py = pIn2;
|
|
|
|
|
|
/* ------------------------
|
|
* Stage1 process
|
|
* ----------------------*/
|
|
|
|
/* The first stage starts here */
|
|
while(blockSize1 > 0u)
|
|
{
|
|
/* 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 = pIn2 + count;
|
|
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 */
|
|
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 by 3 */
|
|
blkCnt = blockSize2 / 3;
|
|
|
|
while(blkCnt > 0u)
|
|
{
|
|
/* Set all accumulators to zero */
|
|
acc0 = 0;
|
|
acc1 = 0;
|
|
acc2 = 0;
|
|
|
|
/* read x[0], x[1], x[2] 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[3] 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[4] 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[5] 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);
|
|
|
|
/* update scratch pointers */
|
|
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 results in the accumulators 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 */
|
|
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 */
|
|
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 = 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 */
|
|
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 */
|
|
|
|
/* 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 > 0u)
|
|
{
|
|
/* Accumulator is made zero for every iteration */
|
|
sum = 0;
|
|
|
|
/* Apply loop unrolling and compute 4 MACs simultaneously. */
|
|
k = blockSize3 >> 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 += (q63_t) * px++ * (*py--);
|
|
/* sum += x[srcALen - srcBLen + 2] * y[srcBLen - 2] */
|
|
sum += (q63_t) * px++ * (*py--);
|
|
/* sum += x[srcALen - srcBLen + 3] * y[srcBLen - 3] */
|
|
sum += (q63_t) * px++ * (*py--);
|
|
/* sum += x[srcALen - srcBLen + 4] * y[srcBLen - 4] */
|
|
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 = blockSize3 % 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 loop counter */
|
|
blockSize3--;
|
|
}
|
|
|
|
#else
|
|
|
|
/* Run the below code for Cortex-M0 */
|
|
|
|
q31_t *pIn1 = pSrcA; /* input pointer */
|
|
q31_t *pIn2 = pSrcB; /* coefficient pointer */
|
|
q63_t sum; /* Accumulator */
|
|
uint32_t i, j; /* loop counter */
|
|
|
|
/* Loop to calculate output of convolution for output length number of times */
|
|
for (i = 0; i < (srcALen + srcBLen - 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);
|
|
}
|
|
|
|
#endif /* #ifndef ARM_MATH_CM0_FAMILY */
|
|
|
|
}
|
|
|
|
/**
|
|
* @} end of Conv group
|
|
*/
|