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Functions

Name
void plp_dot_prod_q8s_xpulpv2(const int8_t restrict pSrcA, const int8_t restrict pSrcB, uint32_t blockSize, uint32_t deciPoint, int32_t *restrict pRes)
Scalar dot product of 8-bit fixed point vectors singlecore kernel for XPULPV2 extension.

Functions Documentation

function plp_dot_prod_q8s_xpulpv2

void plp_dot_prod_q8s_xpulpv2(
    const int8_t *__restrict__ pSrcA,
    const int8_t *__restrict__ pSrcB,
    uint32_t blockSize,
    uint32_t deciPoint,
    int32_t *__restrict__ pRes
)

Scalar dot product of 8-bit fixed point vectors singlecore kernel for XPULPV2 extension.

Parameters:

  • pSrcA points to the first input vector [8 bit]
  • pSrcB points to the second input vector [8 bit]
  • blockSize number of samples in each vector
  • deciPoint decimal point for right shift
  • pRes output result returned here [32 bit]

Return: none

Par: Exploiting SIMD instructions

The 8 bit values are packed four by four into 32 bit vectors and then the four dot products are performed on 32 bit vectors, with 32 bit accumulator.

Source code

/* =====================================================================
 * Project:      PULP DSP Library
 * Title:        plp_dot_prod_q8s_xpulpv2.c
 * Description:  8-bit fixed point vectorized dot product for XPULPV2
 *
 * $Date:        28. May 2019
 * $Revision:    V0
 *
 * Target Processor: PULP cores
 * ===================================================================== */
/*
 * Copyright (C) 2019 ETH Zurich and University of Bologna.
 *
 * Author: Xiaying Wang, ETH Zurich
 *
 * 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.
 *
 * Notice: project inspired by ARM CMSIS DSP and parts of source code
 * ported and adopted for RISC-V PULP platform from ARM CMSIS DSP
 * released under Copyright (C) 2010-2019 ARM Limited or its affiliates
 * with Apache-2.0.
 */

#include "plp_math.h"

void plp_dot_prod_q8s_xpulpv2(const int8_t *__restrict__ pSrcA,
                              const int8_t *__restrict__ pSrcB,
                              uint32_t blockSize,
                              uint32_t deciPoint,
                              int32_t *__restrict__ pRes) {

    uint32_t blkCnt, tmpBS; /* Loop counter, temporal BlockSize */
    int32_t sum = 0;        /* Temporary return variable */

#if defined(PLP_MATH_LOOPUNROLL)

    tmpBS = (blockSize >> 3);

    for (blkCnt = 0; blkCnt < tmpBS; blkCnt++) {

        v4s a0 = *((v4s *)((void *)(pSrcA + 8 * blkCnt)));
        v4s b0 = *((v4s *)((void *)(pSrcB + 8 * blkCnt)));
        v4s a1 = *((v4s *)((void *)(pSrcA + 8 * blkCnt + 4)));
        v4s b1 = *((v4s *)((void *)(pSrcB + 8 * blkCnt + 4)));
        // sum = __SUMDOTP4(a0, b0, sum);
        // sum = sum >> deciPoint;
        // sum = __SUMDOTP4(a1, b1, sum);
        // sum = sum >> deciPoint;
        int32_t x0 = __DOTP4(a0, b0);
        int32_t x1 = __DOTP4(a1, b1);
        sum += __ADDROUNDNORM_REG(x0, x1, deciPoint);

        // sum = __MAC(sum, (*pSrcA++), (*pSrcB++));
        // sum = __MAC(sum, (*pSrcA++), (*pSrcB++));
    }

    tmpBS = (blockSize % 8U);

    for (blkCnt = 0; blkCnt < tmpBS; blkCnt++) {
        int8_t a = *((int8_t *)(pSrcA + 8 * (blockSize / 8) + blkCnt));
        int8_t b = *((int8_t *)(pSrcB + 8 * (blockSize / 8) + blkCnt));
        // sum += a*b;
        // sum = sum >> deciPoint;
        sum += __ROUNDNORM_REG(a * b, deciPoint);
        // sum = __MAC(sum, (*pSrcA++), (*pSrcB++));
    }

#else // PLP_MATH_LOOPUNROLL

    for (blkCnt = 0; blkCnt < blockSize; blkCnt++) {
        // sum = __MAC(sum, (*pSrcA++), (*pSrcB++));
        // sum = sum >> deciPoint;
        sum += __ROUNDNORM_REG((*pSrcA++) * (*pSrcB++), deciPoint);
    }

#endif // PLP_MATH_LOOPUNROLL

    *pRes = sum;
}

Updated on 2023-03-01 at 16:16:32 +0000