p = (P_)&((StgRetDyn *)p)->payload[0];
size = RET_DYN_BITMAP_SIZE;
p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
// skip over the non-ptr words
p = (P_)&((StgRetDyn *)p)->payload[0];
size = RET_DYN_BITMAP_SIZE;
p = retain_small_bitmap(p, size, bitmap, c, c_child_r);
// skip over the non-ptr words