avoid increasing "extra" without also extending the div array

[platform/upstream/isl.git] / isl_map.c

diff --git a/isl_map.c b/isl_map.c
index 07064a1..5ef0d1b 100644 (file)
--- a/isl_map.c
+++ b/isl_map.c
@@ -938,6 +938,13 @@ static void constraint_drop_vars(isl_int *c, unsigned n, unsigned rem)
        isl_seq_clr(c + rem, n);
 }
 
+/* Drop n dimensions starting at first.
+ *
+ * In principle, this frees up some extra variables as the number
+ * of columns remains constant, but we would have to extend
+ * the div array too as the number of rows in this array is assumed
+ * to be equal to extra.
+ */
 struct isl_basic_set *isl_basic_set_drop_dims(
                struct isl_basic_set *bset, unsigned first, unsigned n)
 {
@@ -970,7 +977,6 @@ struct isl_basic_set *isl_basic_set_drop_dims(
        bset->dim = isl_dim_drop_outputs(bset->dim, first, n);
        if (!bset->dim)
                goto error;
-       bset->extra += n;
 
        F_CLR(bset, ISL_BASIC_SET_NORMALIZED);
        bset = isl_basic_set_simplify(bset);
@@ -1012,6 +1018,13 @@ error:
        return NULL;
 }
 
+/* Drop n input dimensions starting at first.
+ *
+ * In principle, this frees up some extra variables as the number
+ * of columns remains constant, but we would have to extend
+ * the div array too as the number of rows in this array is assumed
+ * to be equal to extra.
+ */
 struct isl_basic_map *isl_basic_map_drop_inputs(
                struct isl_basic_map *bmap, unsigned first, unsigned n)
 {
@@ -1050,7 +1063,6 @@ struct isl_basic_map *isl_basic_map_drop_inputs(
        bmap->dim = isl_dim_drop_inputs(bmap->dim, first, n);
        if (!bmap->dim)
                goto error;
-       bmap->extra += n;
 
        F_CLR(bmap, ISL_BASIC_MAP_NORMALIZED);
        bmap = isl_basic_map_simplify(bmap);