FORCE_INLINE __m128d _mm_round_pd()

in common/checksum/sse2neon.h [7550:7613]

• 55 lines of code
• 23 McCabe index (conditional complexity)

FORCE_INLINE __m128d _mm_round_pd(__m128d a, int rounding)
{
#if defined(__aarch64__) || defined(_M_ARM64)
    switch (rounding) {
    case (_MM_FROUND_TO_NEAREST_INT | _MM_FROUND_NO_EXC):
        return vreinterpretq_m128d_f64(vrndnq_f64(vreinterpretq_f64_m128d(a)));
    case (_MM_FROUND_TO_NEG_INF | _MM_FROUND_NO_EXC):
        return _mm_floor_pd(a);
    case (_MM_FROUND_TO_POS_INF | _MM_FROUND_NO_EXC):
        return _mm_ceil_pd(a);
    case (_MM_FROUND_TO_ZERO | _MM_FROUND_NO_EXC):
        return vreinterpretq_m128d_f64(vrndq_f64(vreinterpretq_f64_m128d(a)));
    default:  //_MM_FROUND_CUR_DIRECTION
        return vreinterpretq_m128d_f64(vrndiq_f64(vreinterpretq_f64_m128d(a)));
    }
#else
    double *v_double = (double *) &a;

    if (rounding == (_MM_FROUND_TO_NEAREST_INT | _MM_FROUND_NO_EXC) ||
        (rounding == _MM_FROUND_CUR_DIRECTION &&
         _MM_GET_ROUNDING_MODE() == _MM_ROUND_NEAREST)) {
        double res[2], tmp;
        for (int i = 0; i < 2; i++) {
            tmp = (v_double[i] < 0) ? -v_double[i] : v_double[i];
            double roundDown = floor(tmp);  // Round down value
            double roundUp = ceil(tmp);     // Round up value
            double diffDown = tmp - roundDown;
            double diffUp = roundUp - tmp;
            if (diffDown < diffUp) {
                /* If it's closer to the round down value, then use it */
                res[i] = roundDown;
            } else if (diffDown > diffUp) {
                /* If it's closer to the round up value, then use it */
                res[i] = roundUp;
            } else {
                /* If it's equidistant between round up and round down value,
                 * pick the one which is an even number */
                double half = roundDown / 2;
                if (half != floor(half)) {
                    /* If the round down value is odd, return the round up value
                     */
                    res[i] = roundUp;
                } else {
                    /* If the round up value is odd, return the round down value
                     */
                    res[i] = roundDown;
                }
            }
            res[i] = (v_double[i] < 0) ? -res[i] : res[i];
        }
        return _mm_set_pd(res[1], res[0]);
    } else if (rounding == (_MM_FROUND_TO_NEG_INF | _MM_FROUND_NO_EXC) ||
               (rounding == _MM_FROUND_CUR_DIRECTION &&
                _MM_GET_ROUNDING_MODE() == _MM_ROUND_DOWN)) {
        return _mm_floor_pd(a);
    } else if (rounding == (_MM_FROUND_TO_POS_INF | _MM_FROUND_NO_EXC) ||
               (rounding == _MM_FROUND_CUR_DIRECTION &&
                _MM_GET_ROUNDING_MODE() == _MM_ROUND_UP)) {
        return _mm_ceil_pd(a);
    }
    return _mm_set_pd(v_double[1] > 0 ? floor(v_double[1]) : ceil(v_double[1]),
                      v_double[0] > 0 ? floor(v_double[0]) : ceil(v_double[0]));
#endif
}