diff options
Diffstat (limited to 'fw/hid-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_correlate_q7.c')
| -rw-r--r-- | fw/hid-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_correlate_q7.c | 778 |
1 files changed, 0 insertions, 778 deletions
diff --git a/fw/hid-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_correlate_q7.c b/fw/hid-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_correlate_q7.c deleted file mode 100644 index f8b1df5..0000000 --- a/fw/hid-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_correlate_q7.c +++ /dev/null @@ -1,778 +0,0 @@ -/* ----------------------------------------------------------------------
- * Project: CMSIS DSP Library
- * Title: arm_correlate_q7.c
- * Description: Correlation of Q7 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 Corr
- * @{
- */
-
-/**
- * @brief Correlation of Q7 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 2 * max(srcALen, srcBLen) - 1.
- * @return none.
- *
- * @details
- * <b>Scaling and Overflow Behavior:</b>
- *
- * \par
- * The function is implemented using a 32-bit internal accumulator.
- * Both the inputs are represented in 1.7 format and multiplications yield a 2.14 result.
- * The 2.14 intermediate results are accumulated in a 32-bit accumulator in 18.14 format.
- * This approach provides 17 guard bits and there is no risk of overflow as long as <code>max(srcALen, srcBLen)<131072</code>.
- * The 18.14 result is then truncated to 18.7 format by discarding the low 7 bits and saturated to 1.7 format.
- *
- * \par
- * Refer the function <code>arm_correlate_opt_q7()</code> for a faster implementation of this function.
- *
- */
-
-void arm_correlate_q7(
- q7_t * pSrcA,
- uint32_t srcALen,
- q7_t * pSrcB,
- uint32_t srcBLen,
- q7_t * pDst)
-{
-
-
-#if defined (ARM_MATH_DSP)
-
- /* Run the below code for Cortex-M4 and Cortex-M3 */
-
- q7_t *pIn1; /* inputA pointer */
- q7_t *pIn2; /* inputB pointer */
- q7_t *pOut = pDst; /* output pointer */
- q7_t *px; /* Intermediate inputA pointer */
- q7_t *py; /* Intermediate inputB pointer */
- q7_t *pSrc1; /* Intermediate pointers */
- q31_t sum, acc0, acc1, acc2, acc3; /* Accumulators */
- q31_t input1, input2; /* temporary variables */
- q15_t in1, in2; /* temporary variables */
- q7_t x0, x1, x2, x3, c0, c1; /* temporary variables for holding input and coefficient values */
- uint32_t j, k = 0U, count, blkCnt, outBlockSize, blockSize1, blockSize2, blockSize3; /* loop counter */
- int32_t inc = 1;
-
-
- /* 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 */
- /* But CORR(x, y) is reverse of CORR(y, x) */
- /* So, when srcBLen > srcALen, output pointer is made to point to the end of the output buffer */
- /* and the destination pointer modifier, inc is set to -1 */
- /* If srcALen > srcBLen, zero pad has to be done to srcB to make the two inputs of same length */
- /* But to improve the performance,
- * we include zeroes in the output instead of zero padding either of the the inputs*/
- /* If srcALen > srcBLen,
- * (srcALen - srcBLen) zeroes has to included in the starting of the output buffer */
- /* If srcALen < srcBLen,
- * (srcALen - srcBLen) zeroes has to included in the ending of the output buffer */
- if (srcALen >= srcBLen)
- {
- /* Initialization of inputA pointer */
- pIn1 = (pSrcA);
-
- /* Initialization of inputB pointer */
- pIn2 = (pSrcB);
-
- /* Number of output samples is calculated */
- outBlockSize = (2U * srcALen) - 1U;
-
- /* When srcALen > srcBLen, zero padding is done to srcB
- * to make their lengths equal.
- * Instead, (outBlockSize - (srcALen + srcBLen - 1))
- * number of output samples are made zero */
- j = outBlockSize - (srcALen + (srcBLen - 1U));
-
- /* Updating the pointer position to non zero value */
- pOut += j;
-
- }
- 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;
-
- /* CORR(x, y) = Reverse order(CORR(y, x)) */
- /* Hence set the destination pointer to point to the last output sample */
- pOut = pDst + ((srcALen + srcBLen) - 2U);
-
- /* Destination address modifier is set to -1 */
- inc = -1;
-
- }
-
- /* The function is internally
- * divided into three parts according to the number of multiplications that has to be
- * taken place between inputA samples and inputB samples. In the first part of the
- * algorithm, the multiplications increase by one for every iteration.
- * In the second part of the algorithm, srcBLen number of multiplications are done.
- * In the third part 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[srcBlen - 1]
- * sum = x[0] * y[srcBlen - 2] + x[1] * y[srcBlen - 1]
- * ....
- * sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen - 1] * y[srcBLen - 1]
- */
-
- /* 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 */
- pSrc1 = pIn2 + (srcBLen - 1U);
- py = pSrc1;
-
- /* ------------------------
- * 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 >> 2;
-
- /* 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] , x[1] */
- in1 = (q15_t) * px++;
- in2 = (q15_t) * px++;
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* y[srcBLen - 4] , y[srcBLen - 3] */
- in1 = (q15_t) * py++;
- in2 = (q15_t) * py++;
- input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* x[0] * y[srcBLen - 4] */
- /* x[1] * y[srcBLen - 3] */
- sum = __SMLAD(input1, input2, sum);
-
- /* x[2] , x[3] */
- in1 = (q15_t) * px++;
- in2 = (q15_t) * px++;
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* y[srcBLen - 2] , y[srcBLen - 1] */
- in1 = (q15_t) * py++;
- in2 = (q15_t) * py++;
- input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* x[2] * y[srcBLen - 2] */
- /* x[3] * y[srcBLen - 1] */
- sum = __SMLAD(input1, input2, sum);
-
-
- /* 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 */
- /* x[0] * y[srcBLen - 1] */
- sum += (q31_t) ((q15_t) * px++ * *py++);
-
- /* Decrement the loop counter */
- k--;
- }
-
- /* Store the result in the accumulator in the destination buffer. */
- *pOut = (q7_t) (__SSAT(sum >> 7, 8));
- /* Destination pointer is updated according to the address modifier, inc */
- pOut += inc;
-
- /* Update the inputA and inputB pointers for next MAC calculation */
- py = pSrc1 - count;
- px = pIn1;
-
- /* Increment the MAC count */
- count++;
-
- /* Decrement the loop counter */
- blockSize1--;
- }
-
- /* --------------------------
- * Initializations of stage2
- * ------------------------*/
-
- /* sum = x[0] * y[0] + x[1] * y[1] +...+ x[srcBLen-1] * y[srcBLen-1]
- * sum = x[1] * y[0] + x[2] * y[1] +...+ x[srcBLen] * y[srcBLen-1]
- * ....
- * sum = x[srcALen-srcBLen-2] * y[0] + x[srcALen-srcBLen-1] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
- */
-
- /* Working pointer of inputA */
- px = pIn1;
-
- /* Working pointer of inputB */
- py = pIn2;
-
- /* 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 blockSize2, by 4 */
- blkCnt = blockSize2 >> 2U;
-
- while (blkCnt > 0U)
- {
- /* Set all accumulators to zero */
- acc0 = 0;
- acc1 = 0;
- acc2 = 0;
- acc3 = 0;
-
- /* read x[0], x[1], x[2] samples */
- x0 = *px++;
- x1 = *px++;
- x2 = *px++;
-
- /* 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 y[0] sample */
- c0 = *py++;
- /* Read y[1] sample */
- c1 = *py++;
-
- /* Read x[3] sample */
- x3 = *px++;
-
- /* x[0] and x[1] are packed */
- in1 = (q15_t) x0;
- in2 = (q15_t) x1;
-
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* y[0] and y[1] are packed */
- in1 = (q15_t) c0;
- in2 = (q15_t) c1;
-
- input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* acc0 += x[0] * y[0] + x[1] * y[1] */
- acc0 = __SMLAD(input1, input2, acc0);
-
- /* x[1] and x[2] are packed */
- in1 = (q15_t) x1;
- in2 = (q15_t) x2;
-
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* acc1 += x[1] * y[0] + x[2] * y[1] */
- acc1 = __SMLAD(input1, input2, acc1);
-
- /* x[2] and x[3] are packed */
- in1 = (q15_t) x2;
- in2 = (q15_t) x3;
-
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* acc2 += x[2] * y[0] + x[3] * y[1] */
- acc2 = __SMLAD(input1, input2, acc2);
-
- /* Read x[4] sample */
- x0 = *(px++);
-
- /* x[3] and x[4] are packed */
- in1 = (q15_t) x3;
- in2 = (q15_t) x0;
-
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* acc3 += x[3] * y[0] + x[4] * y[1] */
- acc3 = __SMLAD(input1, input2, acc3);
-
- /* Read y[2] sample */
- c0 = *py++;
- /* Read y[3] sample */
- c1 = *py++;
-
- /* Read x[5] sample */
- x1 = *px++;
-
- /* x[2] and x[3] are packed */
- in1 = (q15_t) x2;
- in2 = (q15_t) x3;
-
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* y[2] and y[3] are packed */
- in1 = (q15_t) c0;
- in2 = (q15_t) c1;
-
- input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* acc0 += x[2] * y[2] + x[3] * y[3] */
- acc0 = __SMLAD(input1, input2, acc0);
-
- /* x[3] and x[4] are packed */
- in1 = (q15_t) x3;
- in2 = (q15_t) x0;
-
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* acc1 += x[3] * y[2] + x[4] * y[3] */
- acc1 = __SMLAD(input1, input2, acc1);
-
- /* x[4] and x[5] are packed */
- in1 = (q15_t) x0;
- in2 = (q15_t) x1;
-
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* acc2 += x[4] * y[2] + x[5] * y[3] */
- acc2 = __SMLAD(input1, input2, acc2);
-
- /* Read x[6] sample */
- x2 = *px++;
-
- /* x[5] and x[6] are packed */
- in1 = (q15_t) x1;
- in2 = (q15_t) x2;
-
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* acc3 += x[5] * y[2] + x[6] * y[3] */
- acc3 = __SMLAD(input1, input2, acc3);
-
- } while (--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)
- {
- /* Read y[4] sample */
- c0 = *py++;
-
- /* Read x[7] sample */
- x3 = *px++;
-
- /* Perform the multiply-accumulates */
- /* acc0 += x[4] * y[4] */
- acc0 += ((q15_t) x0 * c0);
- /* acc1 += x[5] * y[4] */
- acc1 += ((q15_t) x1 * c0);
- /* acc2 += x[6] * y[4] */
- acc2 += ((q15_t) x2 * c0);
- /* acc3 += x[7] * y[4] */
- acc3 += ((q15_t) x3 * c0);
-
- /* Reuse the present samples for the next MAC */
- x0 = x1;
- x1 = x2;
- x2 = x3;
-
- /* Decrement the loop counter */
- k--;
- }
-
- /* Store the result in the accumulator in the destination buffer. */
- *pOut = (q7_t) (__SSAT(acc0 >> 7, 8));
- /* Destination pointer is updated according to the address modifier, inc */
- pOut += inc;
-
- *pOut = (q7_t) (__SSAT(acc1 >> 7, 8));
- pOut += inc;
-
- *pOut = (q7_t) (__SSAT(acc2 >> 7, 8));
- pOut += inc;
-
- *pOut = (q7_t) (__SSAT(acc3 >> 7, 8));
- pOut += inc;
-
- count += 4U;
- /* Update the inputA and inputB pointers for next MAC calculation */
- px = pIn1 + count;
- py = pIn2;
-
- /* 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 = 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)
- {
- /* Reading two inputs of SrcA buffer and packing */
- in1 = (q15_t) * px++;
- in2 = (q15_t) * px++;
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* Reading two inputs of SrcB buffer and packing */
- in1 = (q15_t) * py++;
- in2 = (q15_t) * py++;
- input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* Perform the multiply-accumulates */
- sum = __SMLAD(input1, input2, sum);
-
- /* Reading two inputs of SrcA buffer and packing */
- in1 = (q15_t) * px++;
- in2 = (q15_t) * px++;
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* Reading two inputs of SrcB buffer and packing */
- in1 = (q15_t) * py++;
- in2 = (q15_t) * py++;
- input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* Perform the multiply-accumulates */
- sum = __SMLAD(input1, input2, sum);
-
- /* 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 += ((q15_t) * px++ * *py++);
-
- /* Decrement the loop counter */
- k--;
- }
-
- /* Store the result in the accumulator in the destination buffer. */
- *pOut = (q7_t) (__SSAT(sum >> 7, 8));
- /* Destination pointer is updated according to the address modifier, inc */
- pOut += inc;
-
- /* Increment the pointer pIn1 index, count by 1 */
- count++;
-
- /* Update the inputA and inputB pointers for next MAC calculation */
- px = pIn1 + count;
- py = pIn2;
-
- /* 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;
-
- /* Loop over srcBLen */
- k = srcBLen;
-
- while (k > 0U)
- {
- /* Perform the multiply-accumulate */
- sum += ((q15_t) * px++ * *py++);
-
- /* Decrement the loop counter */
- k--;
- }
-
- /* Store the result in the accumulator in the destination buffer. */
- *pOut = (q7_t) (__SSAT(sum >> 7, 8));
- /* Destination pointer is updated according to the address modifier, inc */
- pOut += inc;
-
- /* Increment the MAC count */
- count++;
-
- /* Update the inputA and inputB pointers for next MAC calculation */
- px = pIn1 + count;
- py = pIn2;
-
-
- /* Decrement the loop counter */
- blkCnt--;
- }
- }
-
- /* --------------------------
- * Initializations of stage3
- * -------------------------*/
-
- /* sum += x[srcALen-srcBLen+1] * y[0] + x[srcALen-srcBLen+2] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
- * sum += x[srcALen-srcBLen+2] * y[0] + x[srcALen-srcBLen+3] * y[1] +...+ x[srcALen-1] * y[srcBLen-1]
- * ....
- * sum += x[srcALen-2] * y[0] + x[srcALen-1] * y[1]
- * sum += x[srcALen-1] * y[0]
- */
-
- /* 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 */
- py = pIn2;
-
- /* -------------------
- * Stage3 process
- * ------------------*/
-
- while (blockSize3 > 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[srcALen - srcBLen + 1] , x[srcALen - srcBLen + 2] */
- in1 = (q15_t) * px++;
- in2 = (q15_t) * px++;
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* y[0] , y[1] */
- in1 = (q15_t) * py++;
- in2 = (q15_t) * py++;
- input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* sum += x[srcALen - srcBLen + 1] * y[0] */
- /* sum += x[srcALen - srcBLen + 2] * y[1] */
- sum = __SMLAD(input1, input2, sum);
-
- /* x[srcALen - srcBLen + 3] , x[srcALen - srcBLen + 4] */
- in1 = (q15_t) * px++;
- in2 = (q15_t) * px++;
- input1 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* y[2] , y[3] */
- in1 = (q15_t) * py++;
- in2 = (q15_t) * py++;
- input2 = ((q31_t) in1 & 0x0000FFFF) | ((q31_t) in2 << 16);
-
- /* sum += x[srcALen - srcBLen + 3] * y[2] */
- /* sum += x[srcALen - srcBLen + 4] * y[3] */
- sum = __SMLAD(input1, input2, sum);
-
- /* 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 += ((q15_t) * px++ * *py++);
-
- /* Decrement the loop counter */
- k--;
- }
-
- /* Store the result in the accumulator in the destination buffer. */
- *pOut = (q7_t) (__SSAT(sum >> 7, 8));
- /* Destination pointer is updated according to the address modifier, inc */
- pOut += inc;
-
- /* Update the inputA and inputB pointers for next MAC calculation */
- px = ++pSrc1;
- py = pIn2;
-
- /* Decrement the MAC count */
- count--;
-
- /* Decrement the loop counter */
- blockSize3--;
- }
-
-#else
-
-/* Run the below code for Cortex-M0 */
-
- q7_t *pIn1 = pSrcA; /* inputA pointer */
- q7_t *pIn2 = pSrcB + (srcBLen - 1U); /* inputB pointer */
- q31_t sum; /* Accumulator */
- uint32_t i = 0U, j; /* loop counters */
- uint32_t inv = 0U; /* Reverse order flag */
- uint32_t tot = 0U; /* Length */
-
- /* 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 */
- /* But CORR(x, y) is reverse of CORR(y, x) */
- /* So, when srcBLen > srcALen, output pointer is made to point to the end of the output buffer */
- /* and a varaible, inv is set to 1 */
- /* If lengths are not equal then zero pad has to be done to make the two
- * inputs of same length. But to improve the performance, we include zeroes
- * in the output instead of zero padding either of the the inputs*/
- /* If srcALen > srcBLen, (srcALen - srcBLen) zeroes has to included in the
- * starting of the output buffer */
- /* If srcALen < srcBLen, (srcALen - srcBLen) zeroes has to included in the
- * ending of the output buffer */
- /* Once the zero padding is done the remaining of the output is calcualted
- * using convolution but with the shorter signal time shifted. */
-
- /* Calculate the length of the remaining sequence */
- tot = ((srcALen + srcBLen) - 2U);
-
- if (srcALen > srcBLen)
- {
- /* Calculating the number of zeros to be padded to the output */
- j = srcALen - srcBLen;
-
- /* Initialise the pointer after zero padding */
- pDst += j;
- }
-
- else if (srcALen < srcBLen)
- {
- /* Initialization to inputB pointer */
- pIn1 = pSrcB;
-
- /* Initialization to the end of inputA pointer */
- pIn2 = pSrcA + (srcALen - 1U);
-
- /* Initialisation of the pointer after zero padding */
- pDst = pDst + tot;
-
- /* Swapping the lengths */
- j = srcALen;
- srcALen = srcBLen;
- srcBLen = j;
-
- /* Setting the reverse flag */
- inv = 1;
-
- }
-
- /* Loop to calculate convolution for output length number of times */
- for (i = 0U; i <= tot; i++)
- {
- /* Initialize sum with zero to carry on MAC operations */
- sum = 0;
-
- /* Loop to perform MAC operations according to convolution equation */
- for (j = 0U; j <= i; j++)
- {
- /* Check the array limitations */
- if ((((i - j) < srcBLen) && (j < srcALen)))
- {
- /* z[i] += x[i-j] * y[j] */
- sum += ((q15_t) pIn1[j] * pIn2[-((int32_t) i - j)]);
- }
- }
- /* Store the output in the destination buffer */
- if (inv == 1)
- *pDst-- = (q7_t) __SSAT((sum >> 7U), 8U);
- else
- *pDst++ = (q7_t) __SSAT((sum >> 7U), 8U);
- }
-
-#endif /* #if defined (ARM_MATH_DSP) */
-
-}
-
-/**
- * @} end of Corr group
- */
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