isl_tab_add_ineq and isl_tab_mark_empty: return status instead of isl_tab *

isl_tabs are not reference counted, so it's easier to deal with a status
than to have to keep track of whether the isl_tab may have been destroyed.

diff --git a/isl_affine_hull.c b/isl_affine_hull.c
index a133598..17dd7d8 100644 (file)
--- a/isl_affine_hull.c
+++ b/isl_affine_hull.c
@@ -239,7 +239,7 @@ error:
 static struct isl_vec *outside_point(struct isl_tab *tab, isl_int *eq, int up)
 {
        struct isl_ctx *ctx;
-       struct isl_vec *sample;
+       struct isl_vec *sample = NULL;
        struct isl_tab_undo *snap;
        unsigned dim;
        int k;
@@ -269,7 +269,8 @@ static struct isl_vec *outside_point(struct isl_tab *tab, isl_int *eq, int up)
 
        if (isl_tab_extend_cons(tab, 1) < 0)
                goto error;
-       tab = isl_tab_add_ineq(tab, eq);
+       if (isl_tab_add_ineq(tab, eq) < 0)
+               goto error;
 
        sample = isl_tab_sample(tab);
 

diff --git a/isl_map_simplify.c b/isl_map_simplify.c
index ed9e033..354de11 100644 (file)
--- a/isl_map_simplify.c
+++ b/isl_map_simplify.c
@@ -1581,7 +1581,8 @@ static struct isl_basic_set *uset_gist(struct isl_basic_set *bset,
        if (!tab)
                goto error;
        for (i = 0; i < bset->n_ineq; ++i)
-               tab = isl_tab_add_ineq(tab, bset->ineq[i]);
+               if (isl_tab_add_ineq(tab, bset->ineq[i]) < 0)
+                       goto error;
        bset = isl_basic_set_add_constraints(combined, bset, 0);
        tab = isl_tab_detect_implicit_equalities(tab);
        tab = isl_tab_detect_redundant(tab);

diff --git a/isl_sample.c b/isl_sample.c
index 4e2cdd6..83fbf4e 100644 (file)
--- a/isl_sample.c
+++ b/isl_sample.c
@@ -957,6 +957,7 @@ static int tab_shift_cone(struct isl_tab *tab,
        bset = tab_cone->bset;
        U = isl_mat_drop_cols(U, 0, tab->n_var - tab->n_unbounded);
        for (i = 0; i < bset->n_ineq; ++i) {
+               int ok;
                struct isl_vec *row = NULL;
                if (isl_tab_is_equality(tab_cone, tab_cone->n_eq + i))
                        continue;
@@ -973,9 +974,9 @@ static int tab_shift_cone(struct isl_tab *tab,
                        continue;
                tab = isl_tab_extend(tab, 1);
                isl_int_add(bset->ineq[i][0], bset->ineq[i][0], v);
-               tab = isl_tab_add_ineq(tab, bset->ineq[i]);
+               ok = isl_tab_add_ineq(tab, bset->ineq[i]) >= 0;
                isl_int_sub(bset->ineq[i][0], bset->ineq[i][0], v);
-               if (!tab)
+               if (!ok)
                        goto error;
        }
 

diff --git a/isl_tab.c b/isl_tab.c
index 348fd09..38a3aef 100644 (file)
--- a/isl_tab.c
+++ b/isl_tab.c
@@ -925,17 +925,15 @@ int isl_tab_mark_redundant(struct isl_tab *tab, int row)
        }
 }
 
-struct isl_tab *isl_tab_mark_empty(struct isl_tab *tab)
+int isl_tab_mark_empty(struct isl_tab *tab)
 {
        if (!tab)
-               return NULL;
+               return -1;
        if (!tab->empty && tab->need_undo)
-               if (isl_tab_push(tab, isl_tab_undo_empty) < 0) {
-                       isl_tab_free(tab);
-                       return NULL;
-               }
+               if (isl_tab_push(tab, isl_tab_undo_empty) < 0)
+                       return -1;
        tab->empty = 1;
-       return tab;
+       return 0;
 }
 
 /* Update the rows signs after a pivot of "row" and "col", with "row_sgn"
@@ -1633,25 +1631,25 @@ static int drop_col(struct isl_tab *tab, int col)
 /* Add inequality "ineq" and check if it conflicts with the
  * previously added constraints or if it is obviously redundant.
  */
-struct isl_tab *isl_tab_add_ineq(struct isl_tab *tab, isl_int *ineq)
+int isl_tab_add_ineq(struct isl_tab *tab, isl_int *ineq)
 {
        int r;
        int sgn;
        isl_int cst;
 
        if (!tab)
-               return NULL;
+               return -1;
        if (tab->bset) {
                struct isl_basic_set *bset = tab->bset;
 
-               isl_assert(tab->mat->ctx, tab->n_eq == bset->n_eq, goto error);
+               isl_assert(tab->mat->ctx, tab->n_eq == bset->n_eq, return -1);
                isl_assert(tab->mat->ctx,
-                           tab->n_con == bset->n_eq + bset->n_ineq, goto error);
+                           tab->n_con == bset->n_eq + bset->n_ineq, return -1);
                tab->bset = isl_basic_set_add_ineq(tab->bset, ineq);
                if (isl_tab_push(tab, isl_tab_undo_bset_ineq) < 0)
-                       goto error;
+                       return -1;
                if (!tab->bset)
-                       goto error;
+                       return -1;
        }
        if (tab->cone) {
                isl_int_init(cst);
@@ -1663,28 +1661,25 @@ struct isl_tab *isl_tab_add_ineq(struct isl_tab *tab, isl_int *ineq)
                isl_int_clear(cst);
        }
        if (r < 0)
-               goto error;
+               return -1;
        tab->con[r].is_nonneg = 1;
        if (isl_tab_push_var(tab, isl_tab_undo_nonneg, &tab->con[r]) < 0)
-               goto error;
+               return -1;
        if (isl_tab_row_is_redundant(tab, tab->con[r].index)) {
                if (isl_tab_mark_redundant(tab, tab->con[r].index) < 0)
-                       goto error;
-               return tab;
+                       return -1;
+               return 0;
        }
 
        sgn = restore_row(tab, &tab->con[r]);
        if (sgn < -1)
-               goto error;
+               return -1;
        if (sgn < 0)
                return isl_tab_mark_empty(tab);
        if (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;
-       return tab;
-error:
-       isl_tab_free(tab);
-       return NULL;
+                       return -1;
+       return 0;
 }
 
 /* Pivot a non-negative variable down until it reaches the value zero
@@ -1891,8 +1886,11 @@ struct isl_tab *isl_tab_add_eq(struct isl_tab *tab, isl_int *eq)
                sgn = sign_of_max(tab, var);
                if (sgn < -1)
                        goto error;
-               if (sgn < 0)
-                       return isl_tab_mark_empty(tab);
+               if (sgn < 0) {
+                       if (isl_tab_mark_empty(tab) < 0)
+                               goto error;
+                       return tab;
+               }
        }
 
        var->is_nonneg = 1;
@@ -1921,19 +1919,26 @@ struct isl_tab *isl_tab_from_basic_map(struct isl_basic_map *bmap)
        if (!tab)
                return NULL;
        tab->rational = ISL_F_ISSET(bmap, ISL_BASIC_MAP_RATIONAL);
-       if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY))
-               return isl_tab_mark_empty(tab);
+       if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY)) {
+               if (isl_tab_mark_empty(tab) < 0)
+                       goto error;
+               return tab;
+       }
        for (i = 0; i < bmap->n_eq; ++i) {
                tab = add_eq(tab, bmap->eq[i]);
                if (!tab)
                        return tab;
        }
        for (i = 0; i < bmap->n_ineq; ++i) {
-               tab = isl_tab_add_ineq(tab, bmap->ineq[i]);
-               if (!tab || tab->empty)
+               if (isl_tab_add_ineq(tab, bmap->ineq[i]) < 0)
+                       goto error;
+               if (tab->empty)
                        return tab;
        }
        return tab;
+error:
+       isl_tab_free(tab);
+       return NULL;
 }
 
 struct isl_tab *isl_tab_from_basic_set(struct isl_basic_set *bset)
@@ -2195,8 +2200,11 @@ static struct isl_tab *cut_to_hyperplane(struct isl_tab *tab,
        sgn = sign_of_max(tab, &tab->con[r]);
        if (sgn < -1)
                goto error;
-       if (sgn < 0)
-               return isl_tab_mark_empty(tab);
+       if (sgn < 0) {
+               if (isl_tab_mark_empty(tab) < 0)
+                       goto error;
+               return tab;
+       }
        tab->con[r].is_nonneg = 1;
        if (isl_tab_push_var(tab, isl_tab_undo_nonneg, &tab->con[r]) < 0)
                goto error;

diff --git a/isl_tab.h b/isl_tab.h
index 13919cf..9f55e0c 100644 (file)
--- a/isl_tab.h
+++ b/isl_tab.h
@@ -179,7 +179,7 @@ enum isl_lp_result isl_tab_min(struct isl_tab *tab,
        unsigned flags) WARN_UNUSED;
 
 struct isl_tab *isl_tab_extend(struct isl_tab *tab, unsigned n_new) WARN_UNUSED;
-struct isl_tab *isl_tab_add_ineq(struct isl_tab *tab, isl_int *ineq) WARN_UNUSED;
+int isl_tab_add_ineq(struct isl_tab *tab, isl_int *ineq) WARN_UNUSED;
 struct isl_tab *isl_tab_add_eq(struct isl_tab *tab, isl_int *eq) WARN_UNUSED;
 struct isl_tab *isl_tab_add_valid_eq(struct isl_tab *tab, isl_int *eq) WARN_UNUSED;
 
@@ -216,7 +216,7 @@ struct isl_map *isl_tab_basic_map_partial_lexopt(
 
 struct isl_tab_var *isl_tab_var_from_row(struct isl_tab *tab, int i);
 int isl_tab_mark_redundant(struct isl_tab *tab, int row) WARN_UNUSED;
-struct isl_tab *isl_tab_mark_empty(struct isl_tab *tab);
+int isl_tab_mark_empty(struct isl_tab *tab) WARN_UNUSED;
 struct isl_tab *isl_tab_dup(struct isl_tab *tab);
 struct isl_tab *isl_tab_product(struct isl_tab *tab1, struct isl_tab *tab2);
 int isl_tab_extend_cons(struct isl_tab *tab, unsigned n_new) WARN_UNUSED;

diff --git a/isl_tab_pip.c b/isl_tab_pip.c
index 4758106..8f3311c 100644 (file)
--- a/isl_tab_pip.c
+++ b/isl_tab_pip.c
@@ -1100,8 +1100,11 @@ static struct isl_tab *restore_lexmin(struct isl_tab *tab)
                return tab;
        while ((row = first_neg(tab)) != -1) {
                col = lexmin_pivot_col(tab, row);
-               if (col >= tab->n_col)
-                       return isl_tab_mark_empty(tab);
+               if (col >= tab->n_col) {
+                       if (isl_tab_mark_empty(tab) < 0)
+                               goto error;
+                       return tab;
+               }
                if (col < 0)
                        goto error;
                if (isl_tab_pivot(tab, row, col) < 0)
@@ -1243,8 +1246,11 @@ static struct isl_tab *add_lexmin_eq(struct isl_tab *tab, isl_int *eq)
        row = tab->con[r1].index;
        if (is_constant(tab, row)) {
                if (!isl_int_is_zero(tab->mat->row[row][1]) ||
-                   (tab->M && !isl_int_is_zero(tab->mat->row[row][2])))
-                       return isl_tab_mark_empty(tab);
+                   (tab->M && !isl_int_is_zero(tab->mat->row[row][2]))) {
+                       if (isl_tab_mark_empty(tab) < 0)
+                               goto error;
+                       return tab;
+               }
                if (isl_tab_rollback(tab, snap) < 0)
                        goto error;
                return tab;
@@ -1515,8 +1521,11 @@ static struct isl_tab *cut_to_integer_lexmin(struct isl_tab *tab)
                return tab;
 
        while ((row = first_non_integer(tab, &flags)) != -1) {
-               if (ISL_FL_ISSET(flags, I_VAR))
-                       return isl_tab_mark_empty(tab);
+               if (ISL_FL_ISSET(flags, I_VAR)) {
+                       if (isl_tab_mark_empty(tab) < 0)
+                               goto error;
+                       return tab;
+               }
                row = add_cut(tab, row);
                if (row < 0)
                        goto error;
@@ -1979,8 +1988,11 @@ static struct isl_tab *tab_for_lexmin(struct isl_basic_map *bmap,
                if (!tab->row_sign)
                        goto error;
        }
-       if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY))
-               return isl_tab_mark_empty(tab);
+       if (ISL_F_ISSET(bmap, ISL_BASIC_MAP_EMPTY)) {
+               if (isl_tab_mark_empty(tab) < 0)
+                       goto error;
+               return tab;
+       }
 
        for (i = tab->n_param; i < tab->n_var - tab->n_div; ++i) {
                tab->var[i].is_nonneg = 1;
@@ -2051,6 +2063,7 @@ static int best_split(struct isl_tab *tab, struct isl_tab *context_tab)
                struct isl_tab_undo *snap2;
                struct isl_vec *ineq = NULL;
                int r = 0;
+               int ok;
 
                if (!isl_tab_var_from_row(tab, split)->is_nonneg)
                        continue;
@@ -2060,8 +2073,10 @@ static int best_split(struct isl_tab *tab, struct isl_tab *context_tab)
                ineq = get_row_parameter_ineq(tab, split);
                if (!ineq)
                        return -1;
-               context_tab = isl_tab_add_ineq(context_tab, ineq->el);
+               ok = isl_tab_add_ineq(context_tab, ineq->el) >= 0;
                isl_vec_free(ineq);
+               if (!ok)
+                       return -1;
 
                snap2 = isl_tab_snap(context_tab);
 
@@ -2078,8 +2093,10 @@ static int best_split(struct isl_tab *tab, struct isl_tab *context_tab)
                        ineq = get_row_parameter_ineq(tab, row);
                        if (!ineq)
                                return -1;
-                       context_tab = isl_tab_add_ineq(context_tab, ineq->el);
+                       ok = isl_tab_add_ineq(context_tab, ineq->el) >= 0;
                        isl_vec_free(ineq);
+                       if (!ok)
+                               return -1;
                        var = &context_tab->con[context_tab->n_con - 1];
                        if (!context_tab->empty &&
                            !isl_tab_min_at_most_neg_one(context_tab, var))
@@ -2347,7 +2364,8 @@ static struct isl_tab *tab_detect_nonnegative_parameters(struct isl_tab *tab,
        isl_seq_clr(ineq->el, ineq->size);
        for (i = 0; i < context_tab->n_var; ++i) {
                isl_int_set_si(ineq->el[1 + i], 1);
-               context_tab = isl_tab_add_ineq(context_tab, ineq->el);
+               if (isl_tab_add_ineq(context_tab, ineq->el) < 0)
+                       goto error;
                var = &context_tab->con[context_tab->n_con - 1];
                if (!context_tab->empty &&
                    !isl_tab_min_at_most_neg_one(context_tab, var)) {
@@ -2663,7 +2681,8 @@ static void check_gbr_integer_feasible(struct isl_context_gbr *cgbr)
 
        if (sample->size == 0) {
                isl_vec_free(sample);
-               cgbr->tab = isl_tab_mark_empty(cgbr->tab);
+               if (isl_tab_mark_empty(cgbr->tab) < 0)
+                       goto error;
                return;
        }
 
@@ -2729,7 +2748,8 @@ static void add_gbr_ineq(struct isl_context_gbr *cgbr, isl_int *ineq)
        if (isl_tab_extend_cons(cgbr->tab, 1) < 0)
                goto error;
 
-       cgbr->tab = isl_tab_add_ineq(cgbr->tab, ineq);
+       if (isl_tab_add_ineq(cgbr->tab, ineq) < 0)
+               goto error;
 
        if (cgbr->shifted && !cgbr->shifted->empty && use_shifted(cgbr)) {
                int i;
@@ -2745,7 +2765,8 @@ static void add_gbr_ineq(struct isl_context_gbr *cgbr, isl_int *ineq)
                        isl_int_add(ineq[0], ineq[0], ineq[1 + i]);
                }
 
-               cgbr->shifted = isl_tab_add_ineq(cgbr->shifted, ineq);
+               if (isl_tab_add_ineq(cgbr->shifted, ineq) < 0)
+                       goto error;
 
                for (i = 0; i < dim; ++i) {
                        if (!isl_int_is_neg(ineq[1 + i]))
@@ -2757,7 +2778,8 @@ static void add_gbr_ineq(struct isl_context_gbr *cgbr, isl_int *ineq)
        if (cgbr->cone && cgbr->cone->n_col != cgbr->cone->n_dead) {
                if (isl_tab_extend_cons(cgbr->cone, 1) < 0)
                        goto error;
-               cgbr->cone = isl_tab_add_ineq(cgbr->cone, ineq);
+               if (isl_tab_add_ineq(cgbr->cone, ineq) < 0)
+                       goto error;
        }
 
        return;
@@ -3636,7 +3658,8 @@ static void find_solutions(struct isl_sol *sol, struct isl_tab *tab)
                        break;
                if (ISL_FL_ISSET(flags, I_PAR)) {
                        if (ISL_FL_ISSET(flags, I_VAR)) {
-                               tab = isl_tab_mark_empty(tab);
+                               if (isl_tab_mark_empty(tab) < 0)
+                                       goto error;
                                break;
                        }
                        row = add_cut(tab, row);