bl_mcu_sdk/examples/dsp/BasicMathFunctions_part1/mult.c

#include "ref.h"

void ref_mult_f32(float32_t *pSrcA, float32_t *pSrcB, float32_t *pDst,
                  uint32_t blockSize)
{
    uint32_t i;

    for (i = 0; i < blockSize; i++) {
        pDst[i] = pSrcA[i] * pSrcB[i];
    }
}

void ref_mult_q31(q31_t *pSrcA, q31_t *pSrcB, q31_t *pDst, uint32_t blockSize)
{
    uint32_t i;
    q63_t temp;

    for (i = 0; i < blockSize; i++) {
        temp = ((q63_t)pSrcA[i] * pSrcB[i]) >> 32;
        temp = temp << 1;
        pDst[i] = ref_sat_q31(temp);
    }
}

void ref_mult_q15(q15_t *pSrcA, q15_t *pSrcB, q15_t *pDst, uint32_t blockSize)
{
    uint32_t i;
    q31_t temp;

    for (i = 0; i < blockSize; i++) {
        temp = ((q31_t)pSrcA[i] * pSrcB[i]) >>
               15; // this comment is for JD, this is specifically 15 and not 16
                   // like the q31 case might imply.  This is because NMSIS DSP
                   // lib does it this way.  No other reason.
        pDst[i] = ref_sat_q15(temp);
    }
}

void ref_mult_q7(q7_t *pSrcA, q7_t *pSrcB, q7_t *pDst, uint32_t blockSize)
{
    uint32_t i;
    q15_t temp;

    for (i = 0; i < blockSize; i++) {
        temp = ((q15_t)pSrcA[i] * pSrcB[i]) >> 7;
        pDst[i] = ref_sat_q7(temp);
    }
}