static void render_memory_region(FlatView *view,
                                 MemoryRegion *mr,
                                 Int128 base,
                                 AddrRange clip,
                                 bool readonly)
{
    MemoryRegion *subregion;
    unsigned i;
    hwaddr offset_in_region;
    Int128 remain;
    Int128 now;
    FlatRange fr;
    AddrRange tmp;

    if (!mr->enabled) {
        return;
    }

    int128_addto(&base, int128_make64(mr->addr));
    readonly |= mr->readonly;

    tmp = addrrange_make(base, mr->size);

    if (!addrrange_intersects(tmp, clip)) {
        return;
    }

    clip = addrrange_intersection(tmp, clip);

    /* Render subregions in priority order. */
    QTAILQ_FOREACH(subregion, &mr->subregions, subregions_link) {
        render_memory_region(view, subregion, base, clip, readonly);
    }

    if (!mr->terminates) {
        return;
    }

    offset_in_region = int128_get64(int128_sub(clip.start, base));
    base = clip.start;
    remain = clip.size;

    fr.mr = mr;
    fr.readonly = readonly;

    /* Render the region itself into any gaps left by the current view. */
    for (i = 0; i < view->nr && int128_nz(remain); ++i) {
        if (int128_ge(base, addrrange_end(view->ranges[i].addr))) {
            continue;
        }
        if (int128_lt(base, view->ranges[i].addr.start)) {
            now = int128_min(remain,
                             int128_sub(view->ranges[i].addr.start, base));
            fr.offset_in_region = offset_in_region;
            fr.addr = addrrange_make(base, now);
            flatview_insert(view, i, &fr);
            ++i;
            int128_addto(&base, now);
            offset_in_region += int128_get64(now);
            int128_subfrom(&remain, now);
        }
        now = int128_sub(int128_min(int128_add(base, remain),
                                    addrrange_end(view->ranges[i].addr)),
                         base);
        int128_addto(&base, now);
        offset_in_region += int128_get64(now);
        int128_subfrom(&remain, now);
    }
    if (int128_nz(remain)) {
        fr.offset_in_region = offset_in_region;
        fr.addr = addrrange_make(base, remain);
        flatview_insert(view, i, &fr);
    }
}