89  * We basically perform a depth first search, where in each level i
94  * in turn and then continue to the next level.
96  * The search is implemented iteratively.  "level" identifies the current
98  * level and false if we want the next value.
111 	int level;  in isl_basic_set_scan()  local
146 	level = 0;  in isl_basic_set_scan()
149 	while (level >= 0) {  in isl_basic_set_scan()
152 			res = isl_tab_min(tab, B->row[1 + level],  in isl_basic_set_scan()
153 				    bset->ctx->one, &min->el[level], NULL, 0);  in isl_basic_set_scan()
158 			isl_seq_neg(B->row[1 + level] + 1,  in isl_basic_set_scan()
159 				    B->row[1 + level] + 1, dim);  in isl_basic_set_scan()
160 			res = isl_tab_min(tab, B->row[1 + level],  in isl_basic_set_scan()
161 				    bset->ctx->one, &max->el[level], NULL, 0);  in isl_basic_set_scan()
162 			isl_seq_neg(B->row[1 + level] + 1,  in isl_basic_set_scan()
163 				    B->row[1 + level] + 1, dim);  in isl_basic_set_scan()
164 			isl_int_neg(max->el[level], max->el[level]);  in isl_basic_set_scan()
169 			snap[level] = isl_tab_snap(tab);  in isl_basic_set_scan()
171 			isl_int_add_ui(min->el[level], min->el[level], 1);  in isl_basic_set_scan()
173 		if (empty || isl_int_gt(min->el[level], max->el[level])) {  in isl_basic_set_scan()
174 			level--;  in isl_basic_set_scan()
176 			if (level >= 0)  in isl_basic_set_scan()
177 				if (isl_tab_rollback(tab, snap[level]) < 0)  in isl_basic_set_scan()
181 		if (level == dim - 1 && callback->add == increment_counter) {  in isl_basic_set_scan()
183 					    min->el[level], max->el[level]))  in isl_basic_set_scan()
185 			level--;  in isl_basic_set_scan()
187 			if (level >= 0)  in isl_basic_set_scan()
188 				if (isl_tab_rollback(tab, snap[level]) < 0)  in isl_basic_set_scan()
192 		isl_int_neg(B->row[1 + level][0], min->el[level]);  in isl_basic_set_scan()
193 		if (isl_tab_add_valid_eq(tab, B->row[1 + level]) < 0)  in isl_basic_set_scan()
195 		isl_int_set_si(B->row[1 + level][0], 0);  in isl_basic_set_scan()
196 		if (level < dim - 1) {  in isl_basic_set_scan()
197 			++level;  in isl_basic_set_scan()
204 		if (isl_tab_rollback(tab, snap[level]) < 0)  in isl_basic_set_scan()