From c7619f4cd7c7cbd9c7fe5688c6cd7c7853a52dec Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Wed, 12 Sep 2012 12:30:46 +0200
Subject: [PATCH] add isl_set_is_disjoint

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 doc/user.pod       |  4 ++++
 include/isl/map.h  |  2 ++
 include/isl/set.h  |  2 ++
 isl_map_simplify.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+)

diff --git a/doc/user.pod b/doc/user.pod
index b637d82e..a2892a9a 100644
--- a/doc/user.pod
+++ b/doc/user.pod
@@ -1903,6 +1903,10 @@ Check whether the range of the (basic) relation is a wrapped relation.
 
 	int isl_set_plain_is_disjoint(__isl_keep isl_set *set1,
 		__isl_keep isl_set *set2);
+	int isl_set_is_disjoint(__isl_keep isl_set *set1,
+		__isl_keep isl_set *set2);
+	int isl_map_is_disjoint(__isl_keep isl_map *map1,
+		__isl_keep isl_map *map2);
 
 =item * Subset
 
diff --git a/include/isl/map.h b/include/isl/map.h
index 5aee7b2f..1b7d413d 100644
--- a/include/isl/map.h
+++ b/include/isl/map.h
@@ -515,6 +515,8 @@ __isl_export
 int isl_map_is_strict_subset(__isl_keep isl_map *map1, __isl_keep isl_map *map2);
 __isl_export
 int isl_map_is_equal(__isl_keep isl_map *map1, __isl_keep isl_map *map2);
+__isl_export
+int isl_map_is_disjoint(__isl_keep isl_map *map1, __isl_keep isl_map *map2);
 int isl_basic_map_is_single_valued(__isl_keep isl_basic_map *bmap);
 int isl_map_plain_is_single_valued(__isl_keep isl_map *map);
 __isl_export
diff --git a/include/isl/set.h b/include/isl/set.h
index 64d502e0..bf2440ea 100644
--- a/include/isl/set.h
+++ b/include/isl/set.h
@@ -366,6 +366,8 @@ __isl_export
 int isl_set_is_strict_subset(__isl_keep isl_set *set1, __isl_keep isl_set *set2);
 __isl_export
 int isl_set_is_equal(__isl_keep isl_set *set1, __isl_keep isl_set *set2);
+__isl_export
+int isl_set_is_disjoint(__isl_keep isl_set *set1, __isl_keep isl_set *set2);
 int isl_set_is_singleton(__isl_keep isl_set *set);
 int isl_set_is_box(__isl_keep isl_set *set);
 int isl_set_has_equal_space(__isl_keep isl_set *set1, __isl_keep isl_set *set2);
diff --git a/isl_map_simplify.c b/isl_map_simplify.c
index 2582d08f..2a366529 100644
--- a/isl_map_simplify.c
+++ b/isl_map_simplify.c
@@ -2199,6 +2199,46 @@ int isl_map_plain_is_disjoint(__isl_keep isl_map *map1,
 	return 1;
 }
 
+/* Are "map1" and "map2" disjoint?
+ *
+ * They are disjoint if they are "obviously disjoint" or if one of them
+ * is empty.  Otherwise, they are not disjoint if one of them is universal.
+ * If none of these cases apply, we compute the intersection and see if
+ * the result is empty.
+ */
+int isl_map_is_disjoint(__isl_keep isl_map *map1, __isl_keep isl_map *map2)
+{
+	int disjoint;
+	int intersect;
+	isl_map *test;
+
+	disjoint = isl_map_plain_is_disjoint(map1, map2);
+	if (disjoint < 0 || disjoint)
+		return disjoint;
+
+	disjoint = isl_map_is_empty(map1);
+	if (disjoint < 0 || disjoint)
+		return disjoint;
+
+	disjoint = isl_map_is_empty(map2);
+	if (disjoint < 0 || disjoint)
+		return disjoint;
+
+	intersect = isl_map_plain_is_universe(map1);
+	if (intersect < 0 || intersect)
+		return intersect < 0 ? -1 : 0;
+
+	intersect = isl_map_plain_is_universe(map2);
+	if (intersect < 0 || intersect)
+		return intersect < 0 ? -1 : 0;
+
+	test = isl_map_intersect(isl_map_copy(map1), isl_map_copy(map2));
+	disjoint = isl_map_is_empty(test);
+	isl_map_free(test);
+
+	return disjoint;
+}
+
 int isl_set_plain_is_disjoint(__isl_keep isl_set *set1,
 	__isl_keep isl_set *set2)
 {
@@ -2206,6 +2246,13 @@ int isl_set_plain_is_disjoint(__isl_keep isl_set *set1,
 					(struct isl_map *)set2);
 }
 
+/* Are "set1" and "set2" disjoint?
+ */
+int isl_set_is_disjoint(__isl_keep isl_set *set1, __isl_keep isl_set *set2)
+{
+	return isl_map_is_disjoint(set1, set2);
+}
+
 int isl_set_fast_is_disjoint(__isl_keep isl_set *set1, __isl_keep isl_set *set2)
 {
 	return isl_set_plain_is_disjoint(set1, set2);
-- 
2.11.4.GIT