isl_basic_map_drop_redundant_divs: also investigate divs that have a definition

They may have become redundant after having been defined.

diff --git a/isl_map_simplify.c b/isl_map_simplify.c
index 65399ab..38981aa 100644 (file)
--- a/isl_map_simplify.c
+++ b/isl_map_simplify.c
@@ -2277,9 +2277,9 @@ struct isl_basic_map *isl_basic_map_drop_redundant_divs(
                int pos, neg;
                int last_pos, last_neg;
                int redundant;
+               int defined;
 
-               if (!isl_int_is_zero(bmap->div[i][0]))
-                       continue;
+               defined = !isl_int_is_zero(bmap->div[i][0]);
                for (j = 0; j < bmap->n_eq; ++j)
                        if (!isl_int_is_zero(bmap->eq[j][1 + off + i]))
                                break;
@@ -2324,7 +2324,8 @@ struct isl_basic_map *isl_basic_map_drop_redundant_divs(
                isl_int_sub(bmap->ineq[last_pos][0],
                            bmap->ineq[last_pos][0], bmap->ineq[last_neg][0]);
                if (!redundant) {
-                       if (!ok_to_set_div_from_bound(bmap, i, last_pos)) {
+                       if (defined ||
+                           !ok_to_set_div_from_bound(bmap, i, last_pos)) {
                                pairs[i] = 0;
                                --n;
                                continue;