basis_reduction_tab.c: use isl_tab_product to construct product tableau

Before, we would manually construct a tableau for the Cartesian
product of a set with itself.  Now, we first create a tableau
for the set and then construct the product tableau.
This should be more efficient and allows us to refactor
the code to pass in a tableau instead of a set.

diff --git a/basis_reduction_tab.c b/basis_reduction_tab.c
index c4075a7..afe51fe 100644 (file)
--- a/basis_reduction_tab.c
+++ b/basis_reduction_tab.c
@@ -64,26 +64,20 @@ static struct isl_tab *gbr_tab(struct isl_basic_set *bset,
        int i, j;
        unsigned dim;
        struct isl_tab *tab;
+       struct isl_tab *prod;
 
        if (!bset || !row)
                return NULL;
 
        dim = isl_basic_set_total_dim(bset);
-       tab = isl_tab_alloc(bset->ctx, 2 * bset->n_ineq + 3 * dim + 1, 2 * dim, 0);
-
-       for (i = 0; i < 2; ++i) {
-               isl_seq_clr(row->el + 1 + (1 - i) * dim, dim);
-               for (j = 0; j < bset->n_ineq; ++j) {
-                       isl_int_set(row->el[0], bset->ineq[j][0]);
-                       isl_seq_cpy(row->el + 1 + i * dim,
-                                   bset->ineq[j] + 1, dim);
-                       tab = isl_tab_add_ineq(tab, row->el);
-                       if (!tab || tab->empty)
-                               return tab;
-               }
+       tab = isl_tab_from_basic_set(bset);
+       prod = isl_tab_product(tab, tab);
+       isl_tab_free(tab);
+       if (isl_tab_extend_cons(prod, 3 * dim + 1) < 0) {
+               isl_tab_free(prod);
+               return NULL;
        }
-
-       return tab;
+       return prod;
 }
 
 static struct tab_lp *init_lp(struct isl_basic_set *bset)