isl_pw_templ.c: extract out isl_pw_*_exploit_equalities_and_remove_if_empty

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

diff --git a/isl_pw_templ.c b/isl_pw_templ.c
index fb60651..bb8d70e 100644 (file)
--- a/isl_pw_templ.c
+++ b/isl_pw_templ.c
@@ -696,6 +696,37 @@ __isl_give isl_set *FN(PW,domain)(__isl_take PW *pw)
        return dom;
 }
 
+/* Exploit the equalities in the domain of piece "i" of "pw"
+ * to simplify the associated function.
+ * If the domain of piece "i" is empty, then remove it entirely,
+ * replacing it with the final piece.
+ */
+static int FN(PW,exploit_equalities_and_remove_if_empty)(__isl_keep PW *pw,
+       int i)
+{
+       isl_basic_set *aff;
+       int empty = isl_set_plain_is_empty(pw->p[i].set);
+
+       if (empty < 0)
+               return -1;
+       if (empty) {
+               isl_set_free(pw->p[i].set);
+               FN(EL,free)(pw->p[i].FIELD);
+               if (i != pw->n - 1)
+                       pw->p[i] = pw->p[pw->n - 1];
+               pw->n--;
+
+               return 0;
+       }
+
+       aff = isl_set_affine_hull(isl_set_copy(pw->p[i].set));
+       pw->p[i].FIELD = FN(EL,substitute_equalities)(pw->p[i].FIELD, aff);
+       if (!pw->p[i].FIELD)
+               return -1;
+
+       return 0;
+}
+
 /* Restrict the domain of "pw" by combining each cell
  * with "set" through a call to "fn", where "fn" may be
  * isl_set_intersect or isl_set_intersect_params.
@@ -720,22 +751,9 @@ static __isl_give PW *FN(PW,intersect_aligned)(__isl_take PW *pw,
                goto error;
 
        for (i = pw->n - 1; i >= 0; --i) {
-               isl_basic_set *aff;
                pw->p[i].set = fn(pw->p[i].set, isl_set_copy(set));
-               if (!pw->p[i].set)
-                       goto error;
-               aff = isl_set_affine_hull(isl_set_copy(pw->p[i].set));
-               pw->p[i].FIELD = FN(EL,substitute_equalities)(pw->p[i].FIELD,
-                                                               aff);
-               if (!pw->p[i].FIELD)
+               if (FN(PW,exploit_equalities_and_remove_if_empty)(pw, i) < 0)
                        goto error;
-               if (isl_set_plain_is_empty(pw->p[i].set)) {
-                       isl_set_free(pw->p[i].set);
-                       FN(EL,free)(pw->p[i].FIELD);
-                       if (i != pw->n - 1)
-                               pw->p[i] = pw->p[pw->n - 1];
-                       pw->n--;
-               }
        }
        
        isl_set_free(set);