From e76ea1513fab485fb2faf189a2241bf0d4265386 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Sat, 21 Mar 2009 12:47:42 +0100
Subject: [PATCH] isl_map_simplify.c: uset_gist: break early if intersection is
 empty

---
 isl_map_simplify.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/isl_map_simplify.c b/isl_map_simplify.c
index bb48508..faa0b93 100644
--- a/isl_map_simplify.c
+++ b/isl_map_simplify.c
@@ -1409,6 +1409,8 @@ static struct isl_basic_set *uset_gist(struct isl_basic_set *bset,
 					isl_basic_set_copy(context));
 	if (!bset)
 		goto error;
+	if (isl_basic_set_fast_is_empty(bset))
+		goto done;
 
 	if (bset->n_eq > 0) {
 		struct isl_basic_set *affine_hull;
-- 
2.7.4