spv_new_row
sv->array = (alloc_new_rows ? spv_new_row(sv->os, SPV_ROWLEN) : NULL);
p[a] = (alloc_new_rows ? spv_new_row(sv->os, SPV_ROWLEN) : NULL);
p[b] = (alloc_new_rows ? spv_new_row(sv->os, SPV_ROWLEN) : NULL);