hist_entry__cmp_compute
return hist_entry__cmp_compute(right, left, COMPUTE_DELTA, d->idx);
return hist_entry__cmp_compute(right, left, COMPUTE_DELTA_ABS, d->idx);
return hist_entry__cmp_compute(right, left, COMPUTE_RATIO, d->idx);
return hist_entry__cmp_compute(right, left, COMPUTE_WEIGHTED_DIFF, d->idx);