vec_sum_15.c

dsp6713开发板的许多例程.对入门特别有用

void vec_sum(const short *restrict a, const short *restrict b,
             short *restrict c, int len)
{
    int i;
    unsigned a3_a2, a1_a0;
    unsigned b3_b2, b1_b0;
    unsigned c3_c2, c1_c0;

    for (i = 0; i < len; i += 4)
    {
        a3_a2 = _hi(_memd8((void*) &a[i]));
        a1_a0 = _lo(_memd8((void*) &a[i]));

        b3_b2 = _hi(_memd8((void*) &b[i]));
        b1_b0 = _lo(_memd8((void*) &b[i]));
    
        c3_c2 = _add2(b3_b2, a3_a2);
        c1_c0 = _add2(b1_b0, a1_a0);

        _memd8((void*) &c[i]) = _itod(c3_c2, c1_c0);
    }
}