112 #define COLAMD_EMPTY (-1)  macro
531     Col [col].shared3.prev = COLAMD_EMPTY ;  in init_rows_cols()
532     Col [col].shared4.degree_next = COLAMD_EMPTY ;  in init_rows_cols()
880     head [c] = COLAMD_EMPTY ;  in init_scoring()
901       COLAMD_ASSERT (head [score] >= COLAMD_EMPTY) ;  in init_scoring()
905       Col [c].shared3.prev = COLAMD_EMPTY ;  in init_scoring()
910       if (next_col != COLAMD_EMPTY)  in init_scoring()
1011     COLAMD_ASSERT (head [min_score] >= COLAMD_EMPTY) ;  in find_ordering()
1014     while (head [min_score] == COLAMD_EMPTY && min_score < n_col)  in find_ordering()
1022     if (next_col != COLAMD_EMPTY)  in find_ordering()
1024       Col [next_col].shared3.prev = COLAMD_EMPTY ;  in find_ordering()
1130       pivot_row = COLAMD_EMPTY ;  in find_ordering()
1182       COLAMD_ASSERT (cur_score >= COLAMD_EMPTY) ;  in find_ordering()
1183       if (prev_col == COLAMD_EMPTY)  in find_ordering()
1191       if (next_col != COLAMD_EMPTY)  in find_ordering()
1312 	if (head_column > COLAMD_EMPTY)  in find_ordering()
1401       COLAMD_ASSERT (head [cur_score] >= COLAMD_EMPTY) ;  in find_ordering()
1404       Col [col].shared3.prev = COLAMD_EMPTY ;  in find_ordering()
1405       if (next_col != COLAMD_EMPTY)  in find_ordering()
1475     if (!COL_IS_DEAD_PRINCIPAL (i) && Col [i].shared2.order == COLAMD_EMPTY)  in order_children()
1492 	COLAMD_ASSERT (Col [c].shared2.order == COLAMD_EMPTY) ;  in order_children()
1505       } while (Col [c].shared2.order == COLAMD_EMPTY) ;  in order_children()
1600     if (head_column > COLAMD_EMPTY)  in detect_super_cols()
1611     for (super_c = first_col ; super_c != COLAMD_EMPTY ;  in detect_super_cols()
1624 	   c != COLAMD_EMPTY ; c = Col [c].shared4.hash_next)  in detect_super_cols()
1670 	Col [c].shared2.order = COLAMD_EMPTY ;  in detect_super_cols()
1678     if (head_column > COLAMD_EMPTY)  in detect_super_cols()
1681       Col [head_column].shared3.headhash = COLAMD_EMPTY ;  in detect_super_cols()
1686       head [hash] = COLAMD_EMPTY ;  in detect_super_cols()