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Functions

Name
void plp_cmplx_conj_i16_rv32im(const int16_t restrict pSrc, int16_t restrict pDst, uint32_t numSamples)
16-bit integer complex conjugate.

Functions Documentation

function plp_cmplx_conj_i16_rv32im

void plp_cmplx_conj_i16_rv32im(
    const int16_t *__restrict__ pSrc,
    int16_t *__restrict__ pDst,
    uint32_t numSamples
)

16-bit integer complex conjugate.

Parameters:

  • pSrc points to the input vector
  • pDst points to the output vector
  • numSamples number of samples in each vector

Return: none

Source code

/* =====================================================================
 * Project:      PULP DSP Library
 * Title:        plp_cmplx_conj_i16_rv32im.c
 * Description:  32-bit float complex conjugate glue code
 *
 * $Date:        29. June 2020
 * $Revision:    V0
 *
 * Target Processor: PULP cores
 * ===================================================================== */
/*
 * Copyright (C) 2019 ETH Zurich and Ubiversity of Bologna.
 *
 * Author: Hanna Mueller, 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_cmplx_conj_i16_rv32im(const int16_t *__restrict__ pSrc,
                               int16_t *__restrict__ pDst,
                               uint32_t numSamples) {
    uint32_t blkCnt; /* Loop counter */

    /* Initialize blkCnt with number of samples */
    blkCnt = 2 * numSamples;
    int8_t sign = 1;
    while (blkCnt > 0U) {
        /* C[0] + jC[1] = A[0]+ j(-1)A[1] */

        /* Calculate Complex Conjugate and store result in destination buffer. */
        if (sign == 1) {
            *pDst++ = *pSrc++;
        } else {
            int16_t in = *pSrc++;
            *pDst++ = (in == INT16_MIN) ? INT16_MAX : -in;
        }
        sign *= -1;

        /* Decrement loop counter */
        blkCnt--;
    }
}

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