isl_tab_pip.c: restore_lexmin: return int instead of isl_tab *

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>

diff --git a/isl_tab_pip.c b/isl_tab_pip.c
index f6e238a..cf1321d 100644 (file)
--- a/isl_tab_pip.c
+++ b/isl_tab_pip.c
@@ -1155,31 +1155,28 @@ static void check_lexpos(struct isl_tab *tab)
  * smallest increment in the sample point.  If there is no such column
  * then the tableau is infeasible.
  */
-static struct isl_tab *restore_lexmin(struct isl_tab *tab) WARN_UNUSED;
-static struct isl_tab *restore_lexmin(struct isl_tab *tab)
+static int restore_lexmin(struct isl_tab *tab) WARN_UNUSED;
+static int restore_lexmin(struct isl_tab *tab)
 {
        int row, col;
 
        if (!tab)
-               return NULL;
+               return -1;
        if (tab->empty)
-               return tab;
+               return 0;
        while ((row = first_neg(tab)) != -1) {
                col = lexmin_pivot_col(tab, row);
                if (col >= tab->n_col) {
                        if (isl_tab_mark_empty(tab) < 0)
-                               goto error;
-                       return tab;
+                               return -1;
+                       return 0;
                }
                if (col < 0)
-                       goto error;
+                       return -1;
                if (isl_tab_pivot(tab, row, col) < 0)
-                       goto error;
+                       return -1;
        }
-       return tab;
-error:
-       isl_tab_free(tab);
-       return NULL;
+       return 0;
 }
 
 /* Given a row that represents an equality, look for an appropriate
@@ -1320,8 +1317,9 @@ static struct isl_tab *add_lexmin_eq(struct isl_tab *tab, isl_int *eq)
                return tab;
        }
 
-       tab = restore_lexmin(tab);
-       if (!tab || tab->empty)
+       if (restore_lexmin(tab) < 0)
+               goto error;
+       if (tab->empty)
                return tab;
 
        isl_seq_neg(eq, eq, 1 + tab->n_var);
@@ -1333,8 +1331,9 @@ static struct isl_tab *add_lexmin_eq(struct isl_tab *tab, isl_int *eq)
        if (isl_tab_push_var(tab, isl_tab_undo_nonneg, &tab->con[r2]) < 0)
                goto error;
 
-       tab = restore_lexmin(tab);
-       if (!tab || tab->empty)
+       if (restore_lexmin(tab) < 0)
+               goto error;
+       if (tab->empty)
                return tab;
 
        if (!tab->con[r1].is_row) {
@@ -1392,8 +1391,9 @@ static struct isl_tab *add_lexmin_ineq(struct isl_tab *tab, isl_int *ineq)
                return tab;
        }
 
-       tab = restore_lexmin(tab);
-       if (tab && !tab->empty && tab->con[r].is_row &&
+       if (restore_lexmin(tab) < 0)
+               goto error;
+       if (!tab->empty && tab->con[r].is_row &&
                 isl_tab_row_is_redundant(tab, tab->con[r].index))
                if (isl_tab_mark_redundant(tab, tab->con[r].index) < 0)
                        goto error;
@@ -1604,8 +1604,9 @@ static struct isl_tab *cut_to_integer_lexmin(struct isl_tab *tab)
                        if (row < 0)
                                goto error;
                } while ((var = next_non_integer_var(tab, var, &flags)) != -1);
-               tab = restore_lexmin(tab);
-               if (!tab || tab->empty)
+               if (restore_lexmin(tab) < 0)
+                       goto error;
+               if (tab->empty)
                        break;
        }
        return tab;
@@ -2017,8 +2018,8 @@ static struct isl_tab *tab_for_lexmin(struct isl_basic_map *bmap,
                if (!tab || tab->empty)
                        return tab;
        }
-       if (bmap->n_eq)
-               tab = restore_lexmin(tab);
+       if (bmap->n_eq && restore_lexmin(tab) < 0)
+               goto error;
        for (i = 0; i < bmap->n_ineq; ++i) {
                if (max)
                        isl_seq_neg(bmap->ineq[i] + 1 + tab->n_param,
@@ -2514,7 +2515,8 @@ static struct isl_context *isl_context_lex_alloc(struct isl_basic_set *dom)
        clex->context.op = &isl_context_lex_op;
 
        clex->tab = context_tab_for_lexmin(isl_basic_set_copy(dom));
-       clex->tab = restore_lexmin(clex->tab);
+       if (restore_lexmin(clex->tab) < 0)
+               goto error;
        clex->tab = check_integer_feasible(clex->tab);
        if (!clex->tab)
                goto error;
@@ -2994,7 +2996,8 @@ static void propagate_equalities(struct isl_context_gbr *cgbr,
                if (isl_tab_kill_col(tab, j) < 0)
                        goto error;
 
-               tab = restore_lexmin(tab);
+               if (restore_lexmin(tab) < 0)
+                       goto error;
        }
 
        isl_vec_free(eq);
@@ -3640,6 +3643,7 @@ error:
 static void find_solutions(struct isl_sol *sol, struct isl_tab *tab)
 {
        struct isl_context *context;
+       int r;
 
        if (!tab || sol->error)
                goto error;
@@ -3651,7 +3655,7 @@ static void find_solutions(struct isl_sol *sol, struct isl_tab *tab)
        if (context->op->is_empty(context))
                goto done;
 
-       for (; tab && !tab->empty; tab = restore_lexmin(tab)) {
+       for (r = 0; r >= 0 && tab && !tab->empty; r = restore_lexmin(tab)) {
                int flags;
                int row;
                enum isl_tab_row_sign sgn;
@@ -3745,6 +3749,8 @@ static void find_solutions(struct isl_sol *sol, struct isl_tab *tab)
                if (row < 0)
                        goto error;
        }
+       if (r < 0)
+               goto error;
 done:
        sol_add(sol, tab);
        isl_tab_free(tab);