| /* ---------------------------------------------------------------------- |
| * Project: CMSIS DSP Library |
| * Title: arm_conv_partial_fast_q31.c |
| * Description: Fast Q31 Partial convolution |
| * |
| * $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 (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]. |
| * |
| * \par |
| * See <code>arm_conv_partial_q31()</code> for a slower implementation of this function which uses a 64-bit accumulator to provide higher precision. |
| */ |
| |
| arm_status arm_conv_partial_fast_q31( |
| q31_t * pSrcA, |
| uint32_t srcALen, |
| q31_t * pSrcB, |
| uint32_t srcBLen, |
| q31_t * pDst, |
| uint32_t firstIndex, |
| uint32_t numPoints) |
| { |
| 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 */ |
| q31_t sum, acc0, acc1, acc2, acc3; /* Accumulators */ |
| 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 |
| * ----------------------*/ |
| |
| /* 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 = (q31_t) ((((q63_t) sum << 32) + |
| ((q63_t) * px++ * (*py--))) >> 32); |
| |
| /* x[1] * y[srcBLen - 2] */ |
| sum = (q31_t) ((((q63_t) sum << 32) + |
| ((q63_t) * px++ * (*py--))) >> 32); |
| |
| /* x[2] * y[srcBLen - 3] */ |
| sum = (q31_t) ((((q63_t) sum << 32) + |
| ((q63_t) * px++ * (*py--))) >> 32); |
| |
| /* x[3] * 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 = (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 */ |
| 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 blockSize2 */ |
| blkCnt = ((uint32_t) 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[srcBLen - 1] sample */ |
| c0 = *(py--); |
| |
| /* Read x[3] sample */ |
| x3 = *(px++); |
| |
| /* Perform the multiply-accumulate */ |
| /* acc0 += x[0] * y[srcBLen - 1] */ |
| acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x0 * c0)) >> 32); |
| |
| /* acc1 += x[1] * y[srcBLen - 1] */ |
| acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x1 * c0)) >> 32); |
| |
| /* acc2 += x[2] * y[srcBLen - 1] */ |
| acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x2 * c0)) >> 32); |
| |
| /* acc3 += x[3] * y[srcBLen - 1] */ |
| acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x3 * c0)) >> 32); |
| |
| /* Read y[srcBLen - 2] sample */ |
| c0 = *(py--); |
| |
| /* Read x[4] sample */ |
| x0 = *(px++); |
| |
| /* Perform the multiply-accumulate */ |
| /* acc0 += x[1] * y[srcBLen - 2] */ |
| acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x1 * c0)) >> 32); |
| /* acc1 += x[2] * y[srcBLen - 2] */ |
| acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x2 * c0)) >> 32); |
| /* acc2 += x[3] * y[srcBLen - 2] */ |
| acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x3 * c0)) >> 32); |
| /* acc3 += x[4] * y[srcBLen - 2] */ |
| acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x0 * c0)) >> 32); |
| |
| /* Read y[srcBLen - 3] sample */ |
| c0 = *(py--); |
| |
| /* Read x[5] sample */ |
| x1 = *(px++); |
| |
| /* Perform the multiply-accumulates */ |
| /* acc0 += x[2] * y[srcBLen - 3] */ |
| acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x2 * c0)) >> 32); |
| /* acc1 += x[3] * y[srcBLen - 2] */ |
| acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x3 * c0)) >> 32); |
| /* acc2 += x[4] * y[srcBLen - 2] */ |
| acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x0 * c0)) >> 32); |
| /* acc3 += x[5] * y[srcBLen - 2] */ |
| acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x1 * c0)) >> 32); |
| |
| /* Read y[srcBLen - 4] sample */ |
| c0 = *(py--); |
| |
| /* Read x[6] sample */ |
| x2 = *(px++); |
| |
| /* Perform the multiply-accumulates */ |
| /* acc0 += x[3] * y[srcBLen - 4] */ |
| acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x3 * c0)) >> 32); |
| /* acc1 += x[4] * y[srcBLen - 4] */ |
| acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x0 * c0)) >> 32); |
| /* acc2 += x[5] * y[srcBLen - 4] */ |
| acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x1 * c0)) >> 32); |
| /* acc3 += x[6] * y[srcBLen - 4] */ |
| acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x2 * c0)) >> 32); |
| |
| |
| } 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[srcBLen - 5] sample */ |
| c0 = *(py--); |
| |
| /* Read x[7] sample */ |
| x3 = *(px++); |
| |
| /* Perform the multiply-accumulates */ |
| /* acc0 += x[4] * y[srcBLen - 5] */ |
| acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x0 * c0)) >> 32); |
| /* acc1 += x[5] * y[srcBLen - 5] */ |
| acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x1 * c0)) >> 32); |
| /* acc2 += x[6] * y[srcBLen - 5] */ |
| acc2 = (q31_t) ((((q63_t) acc2 << 32) + ((q63_t) x2 * c0)) >> 32); |
| /* acc3 += x[7] * y[srcBLen - 5] */ |
| acc3 = (q31_t) ((((q63_t) acc3 << 32) + ((q63_t) x3 * c0)) >> 32); |
| |
| /* 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++ = (q31_t) (acc0 << 1); |
| *pOut++ = (q31_t) (acc1 << 1); |
| *pOut++ = (q31_t) (acc2 << 1); |
| *pOut++ = (q31_t) (acc3 << 1); |
| |
| /* Increment the pointer pIn1 index, count by 4 */ |
| count += 4U; |
| |
| /* 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 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; |
| |
| /* 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 = (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; |
| |
| /* 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 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 |
| */ |
