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/* ----------------------------------------------------------------------
* 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_partial_fast_q15.c
*
* Description: Fast Q15 Partial convolution.
*
* Target Processor: Cortex-M4/Cortex-M3
*
* 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 PartialConv
* @{
*/
/**
* @brief Partial convolution of Q15 sequences (fast version) for Cortex-M3 and Cortex-M4.
* @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_q15()</code> for a slower implementation of this function which uses a 64-bit accumulator to avoid wrap around distortion.
*/
arm_status arm_conv_partial_fast_q15(
q15_t * pSrcA,
uint32_t srcALen,
q15_t * pSrcB,
uint32_t srcBLen,
q15_t * pDst,
uint32_t firstIndex,
uint32_t numPoints)
{
#ifndef UNALIGNED_SUPPORT_DISABLE
q15_t *pIn1; /* inputA pointer */
q15_t *pIn2; /* inputB pointer */
q15_t *pOut = pDst; /* output pointer */
q31_t sum, acc0, acc1, acc2, acc3; /* Accumulator */
q15_t *px; /* Intermediate inputA pointer */
q15_t *py; /* Intermediate inputB pointer */
q15_t *pSrc1, *pSrc2; /* Intermediate pointers */
q31_t x0, x1, x2, x3, c0;
uint32_t j, k, count, check, blkCnt;
int32_t blockSize1, blockSize2, blockSize3; /* 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_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
* ----------------------*/
/* For loop unrolling by 4, this stage is divided into two. */
/* First part of this stage computes the MAC operations less than 4 */
/* Second part of this stage computes the MAC operations greater than or equal to 4 */
/* The first part of the stage starts here */
while((count < 4u) && (blockSize1 > 0))
{
/* Accumulator is made zero for every iteration */
sum = 0;
/* Loop over number of MAC operations between
* inputA samples and inputB samples */
k = count;
while(k > 0u)
{
/* Perform the multiply-accumulates */
sum = __SMLAD(*px++, *py--, sum);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* Update the inputA and inputB pointers for next MAC calculation */
py = ++pSrc2;
px = pIn1;
/* Increment the MAC count */
count++;
/* Decrement the loop counter */
blockSize1--;
}
/* The second part of the stage starts here */
/* The internal loop, over count, is unrolled by 4 */
/* To, read the last two inputB samples using SIMD:
* y[srcBLen] and y[srcBLen-1] coefficients, py is decremented by 1 */
py = py - 1;
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)
{
/* Perform the multiply-accumulates */
/* x[0], x[1] are multiplied with y[srcBLen - 1], y[srcBLen - 2] respectively */
sum = __SMLADX(*__SIMD32(px)++, *__SIMD32(py)--, sum);
/* x[2], x[3] are multiplied with y[srcBLen - 3], y[srcBLen - 4] respectively */
sum = __SMLADX(*__SIMD32(px)++, *__SIMD32(py)--, sum);
/* Decrement the loop counter */
k--;
}
/* For the next MAC operations, the pointer py is used without SIMD
* So, py is incremented by 1 */
py = py + 1u;
/* 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 = __SMLAD(*px++, *py--, sum);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* Update the inputA and inputB pointers for next MAC calculation */
py = ++pSrc2 - 1u;
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 the 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 blockSize2, by 4 */
blkCnt = ((uint32_t) blockSize2 >> 2u);
while(blkCnt > 0u)
{
py = py - 1u;
/* Set all accumulators to zero */
acc0 = 0;
acc1 = 0;
acc2 = 0;
acc3 = 0;
/* read x[0], x[1] samples */
x0 = *__SIMD32(px);
/* read x[1], x[2] samples */
x1 = _SIMD32_OFFSET(px+1);
px+= 2u;
/* 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. */
do
{
/* Read the last two inputB samples using SIMD:
* y[srcBLen - 1] and y[srcBLen - 2] */
c0 = *__SIMD32(py)--;
/* acc0 += x[0] * y[srcBLen - 1] + x[1] * y[srcBLen - 2] */
acc0 = __SMLADX(x0, c0, acc0);
/* acc1 += x[1] * y[srcBLen - 1] + x[2] * y[srcBLen - 2] */
acc1 = __SMLADX(x1, c0, acc1);
/* Read x[2], x[3] */
x2 = *__SIMD32(px);
/* Read x[3], x[4] */
x3 = _SIMD32_OFFSET(px+1);
/* acc2 += x[2] * y[srcBLen - 1] + x[3] * y[srcBLen - 2] */
acc2 = __SMLADX(x2, c0, acc2);
/* acc3 += x[3] * y[srcBLen - 1] + x[4] * y[srcBLen - 2] */
acc3 = __SMLADX(x3, c0, acc3);
/* Read y[srcBLen - 3] and y[srcBLen - 4] */
c0 = *__SIMD32(py)--;
/* acc0 += x[2] * y[srcBLen - 3] + x[3] * y[srcBLen - 4] */
acc0 = __SMLADX(x2, c0, acc0);
/* acc1 += x[3] * y[srcBLen - 3] + x[4] * y[srcBLen - 4] */
acc1 = __SMLADX(x3, c0, acc1);
/* Read x[4], x[5] */
x0 = _SIMD32_OFFSET(px+2);
/* Read x[5], x[6] */
x1 = _SIMD32_OFFSET(px+3);
px += 4u;
/* acc2 += x[4] * y[srcBLen - 3] + x[5] * y[srcBLen - 4] */
acc2 = __SMLADX(x0, c0, acc2);
/* acc3 += x[5] * y[srcBLen - 3] + x[6] * y[srcBLen - 4] */
acc3 = __SMLADX(x1, c0, acc3);
} while(--k);
/* For the next MAC operations, SIMD is not used
* So, the 16 bit pointer if inputB, py is updated */
/* If the srcBLen is not a multiple of 4, compute any remaining MACs here.
** No loop unrolling is used. */
k = srcBLen % 0x4u;
if(k == 1u)
{
/* Read y[srcBLen - 5] */
c0 = *(py+1);
#ifdef ARM_MATH_BIG_ENDIAN
c0 = c0 << 16u;
#else
c0 = c0 & 0x0000FFFF;
#endif /* #ifdef ARM_MATH_BIG_ENDIAN */
/* Read x[7] */
x3 = *__SIMD32(px);
px++;
/* Perform the multiply-accumulates */
acc0 = __SMLAD(x0, c0, acc0);
acc1 = __SMLAD(x1, c0, acc1);
acc2 = __SMLADX(x1, c0, acc2);
acc3 = __SMLADX(x3, c0, acc3);
}
if(k == 2u)
{
/* Read y[srcBLen - 5], y[srcBLen - 6] */
c0 = _SIMD32_OFFSET(py);
/* Read x[7], x[8] */
x3 = *__SIMD32(px);
/* Read x[9] */
x2 = _SIMD32_OFFSET(px+1);
px += 2u;
/* Perform the multiply-accumulates */
acc0 = __SMLADX(x0, c0, acc0);
acc1 = __SMLADX(x1, c0, acc1);
acc2 = __SMLADX(x3, c0, acc2);
acc3 = __SMLADX(x2, c0, acc3);
}
if(k == 3u)
{
/* Read y[srcBLen - 5], y[srcBLen - 6] */
c0 = _SIMD32_OFFSET(py);
/* Read x[7], x[8] */
x3 = *__SIMD32(px);
/* Read x[9] */
x2 = _SIMD32_OFFSET(px+1);
/* Perform the multiply-accumulates */
acc0 = __SMLADX(x0, c0, acc0);
acc1 = __SMLADX(x1, c0, acc1);
acc2 = __SMLADX(x3, c0, acc2);
acc3 = __SMLADX(x2, c0, acc3);
c0 = *(py-1);
#ifdef ARM_MATH_BIG_ENDIAN
c0 = c0 << 16u;
#else
c0 = c0 & 0x0000FFFF;
#endif /* #ifdef ARM_MATH_BIG_ENDIAN */
/* Read x[10] */
x3 = _SIMD32_OFFSET(px+2);
px += 3u;
/* Perform the multiply-accumulates */
acc0 = __SMLADX(x1, c0, acc0);
acc1 = __SMLAD(x2, c0, acc1);
acc2 = __SMLADX(x2, c0, acc2);
acc3 = __SMLADX(x3, c0, acc3);
}
/* Store the results in the accumulators in the destination buffer. */
#ifndef ARM_MATH_BIG_ENDIAN
*__SIMD32(pOut)++ = __PKHBT(acc0 >> 15, acc1 >> 15, 16);
*__SIMD32(pOut)++ = __PKHBT(acc2 >> 15, acc3 >> 15, 16);
#else
*__SIMD32(pOut)++ = __PKHBT(acc1 >> 15, acc0 >> 15, 16);
*__SIMD32(pOut)++ = __PKHBT(acc3 >> 15, acc2 >> 15, 16);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* Increment the pointer pIn1 index, count by 4 */
count += 4u;
/* 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 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) * px++ * *py--);
sum += ((q31_t) * px++ * *py--);
sum += ((q31_t) * px++ * *py--);
sum += ((q31_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-accumulates */
sum += ((q31_t) * px++ * *py--);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* Increment the pointer pIn1 index, count by 1 */
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 = (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) * px++ * *py--);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* 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 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);
pIn2 = pSrc2 - 1u;
py = pIn2;
/* -------------------
* Stage3 process
* ------------------*/
/* For loop unrolling by 4, this stage is divided into two. */
/* First part of this stage computes the MAC operations greater than 4 */
/* Second part of this stage computes the MAC operations less than or equal to 4 */
/* The first part of the stage starts here */
j = count >> 2u;
while((j > 0u) && (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)
{
/* x[srcALen - srcBLen + 1], x[srcALen - srcBLen + 2] are multiplied
* with y[srcBLen - 1], y[srcBLen - 2] respectively */
sum = __SMLADX(*__SIMD32(px)++, *__SIMD32(py)--, sum);
/* x[srcALen - srcBLen + 3], x[srcALen - srcBLen + 4] are multiplied
* with y[srcBLen - 3], y[srcBLen - 4] respectively */
sum = __SMLADX(*__SIMD32(px)++, *__SIMD32(py)--, sum);
/* Decrement the loop counter */
k--;
}
/* For the next MAC operations, the pointer py is used without SIMD
* So, py is incremented by 1 */
py = py + 1u;
/* 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)
{
/* sum += x[srcALen - srcBLen + 5] * y[srcBLen - 5] */
sum = __SMLAD(*px++, *py--, sum);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* Update the inputA and inputB pointers for next MAC calculation */
px = ++pSrc1;
py = pIn2;
/* Decrement the MAC count */
count--;
/* Decrement the loop counter */
blockSize3--;
j--;
}
/* The second part of the stage starts here */
/* SIMD is not used for the next MAC operations,
* so pointer py is updated to read only one sample at a time */
py = py + 1u;
while(blockSize3 > 0)
{
/* Accumulator is made zero for every iteration */
sum = 0;
/* Apply loop unrolling and compute 4 MACs simultaneously. */
k = count;
while(k > 0u)
{
/* Perform the multiply-accumulates */
/* sum += x[srcALen-1] * y[srcBLen-1] */
sum = __SMLAD(*px++, *py--, sum);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* 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
q15_t *pIn1; /* inputA pointer */
q15_t *pIn2; /* inputB pointer */
q15_t *pOut = pDst; /* output pointer */
q31_t sum, acc0, acc1, acc2, acc3; /* Accumulator */
q15_t *px; /* Intermediate inputA pointer */
q15_t *py; /* Intermediate inputB pointer */
q15_t *pSrc1, *pSrc2; /* Intermediate pointers */
q31_t x0, x1, x2, x3, c0;
uint32_t j, k, count, check, blkCnt;
int32_t blockSize1, blockSize2, blockSize3; /* loop counters */
arm_status status; /* status of Partial convolution */
q15_t a, b;
/* 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
* ----------------------*/
/* For loop unrolling by 4, this stage is divided into two. */
/* First part of this stage computes the MAC operations less than 4 */
/* Second part of this stage computes the MAC operations greater than or equal to 4 */
/* The first part of the stage starts here */
while((count < 4u) && (blockSize1 > 0))
{
/* Accumulator is made zero for every iteration */
sum = 0;
/* Loop over number of MAC operations between
* inputA samples and inputB samples */
k = count;
while(k > 0u)
{
/* Perform the multiply-accumulates */
sum += ((q31_t) * px++ * *py--);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* Update the inputA and inputB pointers for next MAC calculation */
py = ++pSrc2;
px = pIn1;
/* Increment the MAC count */
count++;
/* Decrement the loop counter */
blockSize1--;
}
/* The second part of the stage starts here */
/* The internal loop, over count, is unrolled by 4 */
/* To, read the last two inputB samples using SIMD:
* y[srcBLen] and y[srcBLen-1] coefficients, py is decremented by 1 */
py = py - 1;
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. */
py++;
while(k > 0u)
{
/* Perform the multiply-accumulates */
sum += ((q31_t) * px++ * *py--);
sum += ((q31_t) * px++ * *py--);
sum += ((q31_t) * px++ * *py--);
sum += ((q31_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-accumulates */
sum += ((q31_t) * px++ * *py--);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* Update the inputA and inputB pointers for next MAC calculation */
py = ++pSrc2 - 1u;
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 the 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 blockSize2, by 4 */
blkCnt = ((uint32_t) blockSize2 >> 2u);
while(blkCnt > 0u)
{
py = py - 1u;
/* Set all accumulators to zero */
acc0 = 0;
acc1 = 0;
acc2 = 0;
acc3 = 0;
/* read x[0], x[1] samples */
a = *px++;
b = *px++;
#ifndef ARM_MATH_BIG_ENDIAN
x0 = __PKHBT(a, b, 16);
a = *px;
x1 = __PKHBT(b, a, 16);
#else
x0 = __PKHBT(b, a, 16);
a = *px;
x1 = __PKHBT(a, b, 16);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* 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. */
do
{
/* Read the last two inputB samples using SIMD:
* y[srcBLen - 1] and y[srcBLen - 2] */
a = *py;
b = *(py+1);
py -= 2;
#ifndef ARM_MATH_BIG_ENDIAN
c0 = __PKHBT(a, b, 16);
#else
c0 = __PKHBT(b, a, 16);;
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* acc0 += x[0] * y[srcBLen - 1] + x[1] * y[srcBLen - 2] */
acc0 = __SMLADX(x0, c0, acc0);
/* acc1 += x[1] * y[srcBLen - 1] + x[2] * y[srcBLen - 2] */
acc1 = __SMLADX(x1, c0, acc1);
a = *px;
b = *(px + 1);
#ifndef ARM_MATH_BIG_ENDIAN
x2 = __PKHBT(a, b, 16);
a = *(px + 2);
x3 = __PKHBT(b, a, 16);
#else
x2 = __PKHBT(b, a, 16);
a = *(px + 2);
x3 = __PKHBT(a, b, 16);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* acc2 += x[2] * y[srcBLen - 1] + x[3] * y[srcBLen - 2] */
acc2 = __SMLADX(x2, c0, acc2);
/* acc3 += x[3] * y[srcBLen - 1] + x[4] * y[srcBLen - 2] */
acc3 = __SMLADX(x3, c0, acc3);
/* Read y[srcBLen - 3] and y[srcBLen - 4] */
a = *py;
b = *(py+1);
py -= 2;
#ifndef ARM_MATH_BIG_ENDIAN
c0 = __PKHBT(a, b, 16);
#else
c0 = __PKHBT(b, a, 16);;
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* acc0 += x[2] * y[srcBLen - 3] + x[3] * y[srcBLen - 4] */
acc0 = __SMLADX(x2, c0, acc0);
/* acc1 += x[3] * y[srcBLen - 3] + x[4] * y[srcBLen - 4] */
acc1 = __SMLADX(x3, c0, acc1);
/* Read x[4], x[5], x[6] */
a = *(px + 2);
b = *(px + 3);
#ifndef ARM_MATH_BIG_ENDIAN
x0 = __PKHBT(a, b, 16);
a = *(px + 4);
x1 = __PKHBT(b, a, 16);
#else
x0 = __PKHBT(b, a, 16);
a = *(px + 4);
x1 = __PKHBT(a, b, 16);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
px += 4u;
/* acc2 += x[4] * y[srcBLen - 3] + x[5] * y[srcBLen - 4] */
acc2 = __SMLADX(x0, c0, acc2);
/* acc3 += x[5] * y[srcBLen - 3] + x[6] * y[srcBLen - 4] */
acc3 = __SMLADX(x1, c0, acc3);
} while(--k);
/* For the next MAC operations, SIMD is not used
* So, the 16 bit pointer if inputB, py is updated */
/* If the srcBLen is not a multiple of 4, compute any remaining MACs here.
** No loop unrolling is used. */
k = srcBLen % 0x4u;
if(k == 1u)
{
/* Read y[srcBLen - 5] */
c0 = *(py+1);
#ifdef ARM_MATH_BIG_ENDIAN
c0 = c0 << 16u;
#else
c0 = c0 & 0x0000FFFF;
#endif /* #ifdef ARM_MATH_BIG_ENDIAN */
/* Read x[7] */
a = *px;
b = *(px+1);
px++;
#ifndef ARM_MATH_BIG_ENDIAN
x3 = __PKHBT(a, b, 16);
#else
x3 = __PKHBT(b, a, 16);;
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* Perform the multiply-accumulates */
acc0 = __SMLAD(x0, c0, acc0);
acc1 = __SMLAD(x1, c0, acc1);
acc2 = __SMLADX(x1, c0, acc2);
acc3 = __SMLADX(x3, c0, acc3);
}
if(k == 2u)
{
/* Read y[srcBLen - 5], y[srcBLen - 6] */
a = *py;
b = *(py+1);
#ifndef ARM_MATH_BIG_ENDIAN
c0 = __PKHBT(a, b, 16);
#else
c0 = __PKHBT(b, a, 16);;
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* Read x[7], x[8], x[9] */
a = *px;
b = *(px + 1);
#ifndef ARM_MATH_BIG_ENDIAN
x3 = __PKHBT(a, b, 16);
a = *(px + 2);
x2 = __PKHBT(b, a, 16);
#else
x3 = __PKHBT(b, a, 16);
a = *(px + 2);
x2 = __PKHBT(a, b, 16);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
px += 2u;
/* Perform the multiply-accumulates */
acc0 = __SMLADX(x0, c0, acc0);
acc1 = __SMLADX(x1, c0, acc1);
acc2 = __SMLADX(x3, c0, acc2);
acc3 = __SMLADX(x2, c0, acc3);
}
if(k == 3u)
{
/* Read y[srcBLen - 5], y[srcBLen - 6] */
a = *py;
b = *(py+1);
#ifndef ARM_MATH_BIG_ENDIAN
c0 = __PKHBT(a, b, 16);
#else
c0 = __PKHBT(b, a, 16);;
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* Read x[7], x[8], x[9] */
a = *px;
b = *(px + 1);
#ifndef ARM_MATH_BIG_ENDIAN
x3 = __PKHBT(a, b, 16);
a = *(px + 2);
x2 = __PKHBT(b, a, 16);
#else
x3 = __PKHBT(b, a, 16);
a = *(px + 2);
x2 = __PKHBT(a, b, 16);
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
/* Perform the multiply-accumulates */
acc0 = __SMLADX(x0, c0, acc0);
acc1 = __SMLADX(x1, c0, acc1);
acc2 = __SMLADX(x3, c0, acc2);
acc3 = __SMLADX(x2, c0, acc3);
/* Read y[srcBLen - 7] */
c0 = *(py-1);
#ifdef ARM_MATH_BIG_ENDIAN
c0 = c0 << 16u;
#else
c0 = c0 & 0x0000FFFF;
#endif /* #ifdef ARM_MATH_BIG_ENDIAN */
/* Read x[10] */
a = *(px+2);
b = *(px+3);
#ifndef ARM_MATH_BIG_ENDIAN
x3 = __PKHBT(a, b, 16);
#else
x3 = __PKHBT(b, a, 16);;
#endif /* #ifndef ARM_MATH_BIG_ENDIAN */
px += 3u;
/* Perform the multiply-accumulates */
acc0 = __SMLADX(x1, c0, acc0);
acc1 = __SMLAD(x2, c0, acc1);
acc2 = __SMLADX(x2, c0, acc2);
acc3 = __SMLADX(x3, c0, acc3);
}
/* Store the results in the accumulators in the destination buffer. */
*pOut++ = (q15_t)(acc0 >> 15);
*pOut++ = (q15_t)(acc1 >> 15);
*pOut++ = (q15_t)(acc2 >> 15);
*pOut++ = (q15_t)(acc3 >> 15);
/* Increment the pointer pIn1 index, count by 4 */
count += 4u;
/* 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 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) * px++ * *py--);
sum += ((q31_t) * px++ * *py--);
sum += ((q31_t) * px++ * *py--);
sum += ((q31_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-accumulates */
sum += ((q31_t) * px++ * *py--);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* Increment the pointer pIn1 index, count by 1 */
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 = (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) * px++ * *py--);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* 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 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);
pIn2 = pSrc2 - 1u;
py = pIn2;
/* -------------------
* Stage3 process
* ------------------*/
/* For loop unrolling by 4, this stage is divided into two. */
/* First part of this stage computes the MAC operations greater than 4 */
/* Second part of this stage computes the MAC operations less than or equal to 4 */
/* The first part of the stage starts here */
j = count >> 2u;
while((j > 0u) && (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. */
py++;
while(k > 0u)
{
/* Perform the multiply-accumulates */
sum += ((q31_t) * px++ * *py--);
sum += ((q31_t) * px++ * *py--);
sum += ((q31_t) * px++ * *py--);
sum += ((q31_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-accumulates */
sum += ((q31_t) * px++ * *py--);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* Update the inputA and inputB pointers for next MAC calculation */
px = ++pSrc1;
py = pIn2;
/* Decrement the MAC count */
count--;
/* Decrement the loop counter */
blockSize3--;
j--;
}
/* The second part of the stage starts here */
/* SIMD is not used for the next MAC operations,
* so pointer py is updated to read only one sample at a time */
py = py + 1u;
while(blockSize3 > 0)
{
/* Accumulator is made zero for every iteration */
sum = 0;
/* Apply loop unrolling and compute 4 MACs simultaneously. */
k = count;
while(k > 0u)
{
/* Perform the multiply-accumulates */
/* sum += x[srcALen-1] * y[srcBLen-1] */
sum += ((q31_t) * px++ * *py--);
/* Decrement the loop counter */
k--;
}
/* Store the result in the accumulator in the destination buffer. */
*pOut++ = (q15_t) (sum >> 15);
/* 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);
#endif /* #ifndef UNALIGNED_SUPPORT_DISABLE */
}
/**
* @} end of PartialConv group
*/