add isl_pw_qpolynomial_fold_covers

diff --git a/isl_fold.c b/isl_fold.c
index 036c296..a0bdab3 100644 (file)
--- a/isl_fold.c
+++ b/isl_fold.c
@@ -629,3 +629,92 @@ error:
        isl_qpolynomial_fold_free(fold);
        return NULL;
 }
+
+/* Check whether for each quasi-polynomial in "fold2" there is
+ * a quasi-polynomial in "fold1" that dominates it on "set".
+ */
+static int qpolynomial_fold_covers_on_domain(__isl_keep isl_set *set,
+       __isl_keep isl_qpolynomial_fold *fold1,
+       __isl_keep isl_qpolynomial_fold *fold2)
+{
+       int i, j;
+       int covers;
+
+       if (!set || !fold1 || !fold2)
+               return -1;
+
+       covers = fold1->type == isl_fold_max ? 1 : -1;
+
+       for (i = 0; i < fold2->n; ++i) {
+               for (j = 0; j < fold1->n; ++j) {
+                       isl_qpolynomial *d;
+                       int sgn;
+
+                       d = isl_qpolynomial_sub(
+                               isl_qpolynomial_copy(fold1->qp[j]),
+                               isl_qpolynomial_copy(fold2->qp[i]));
+                       sgn = isl_qpolynomial_sign(set, d);
+                       isl_qpolynomial_free(d);
+                       if (sgn == covers)
+                               break;
+               }
+               if (j >= fold1->n)
+                       return 0;
+       }
+
+       return 1;
+}
+
+/* Check whether "pwf1" dominated "pwf2", i.e., the domain of "pwf1" contains
+ * that of "pwf2" and on each cell, the corresponding fold from pwf1 dominates
+ * that of pwf2.
+ */
+int isl_pw_qpolynomial_fold_covers(__isl_keep isl_pw_qpolynomial_fold *pwf1,
+       __isl_keep isl_pw_qpolynomial_fold *pwf2)
+{
+       int i, j;
+       isl_set *dom1, *dom2;
+       int is_subset;
+
+       if (!pwf1 || !pwf2)
+               return -1;
+
+       if (pwf2->n == 0)
+               return 1;
+       if (pwf1->n == 0)
+               return 0;
+
+       dom1 = isl_pw_qpolynomial_fold_domain(isl_pw_qpolynomial_fold_copy(pwf1));
+       dom2 = isl_pw_qpolynomial_fold_domain(isl_pw_qpolynomial_fold_copy(pwf2));
+       is_subset = isl_set_is_subset(dom2, dom1);
+       isl_set_free(dom1);
+       isl_set_free(dom2);
+
+       if (is_subset < 0 || !is_subset)
+               return is_subset;
+
+       for (i = 0; i < pwf2->n; ++i) {
+               for (j = 0; j < pwf1->n; ++j) {
+                       int is_empty;
+                       isl_set *common;
+                       int covers;
+
+                       common = isl_set_intersect(isl_set_copy(pwf1->p[j].set),
+                                                  isl_set_copy(pwf2->p[i].set));
+                       is_empty = isl_set_is_empty(common);
+                       if (is_empty < 0 || is_empty) {
+                               isl_set_free(common);
+                               if (is_empty < 0)
+                                       return -1;
+                               continue;
+                       }
+                       covers = qpolynomial_fold_covers_on_domain(common,
+                                       pwf1->p[j].fold, pwf2->p[i].fold);
+                       isl_set_free(common);
+                       if (covers < 0 || !covers)
+                               return covers;
+               }
+       }
+
+       return 1;
+}

diff --git a/isl_polynomial_private.h b/isl_polynomial_private.h
index f9ddaf3..c68a94f 100644 (file)
--- a/isl_polynomial_private.h
+++ b/isl_polynomial_private.h
@@ -154,3 +154,6 @@ __isl_give isl_pw_qpolynomial_fold *isl_pw_qpolynomial_fold_cow(
 
 __isl_give isl_qpolynomial *isl_qpolynomial_fold_opt_on_domain(
        __isl_take isl_qpolynomial_fold *fold, __isl_take isl_set *set, int max);
+
+int isl_pw_qpolynomial_fold_covers(__isl_keep isl_pw_qpolynomial_fold *pwf1,
+       __isl_keep isl_pw_qpolynomial_fold *pwf2);