diff --git a/lib/External/isl/GIT_HEAD_ID b/lib/External/isl/GIT_HEAD_ID
index 56d7f75..60beb8f 100644
--- a/lib/External/isl/GIT_HEAD_ID
+++ b/lib/External/isl/GIT_HEAD_ID
@@ -1 +1 @@
-isl-0.24-52-gd7be01f7
+isl-0.24-69-g54aac5ac
diff --git a/lib/External/isl/Makefile.am b/lib/External/isl/Makefile.am
index d403e26..3e7d7b1 100644
--- a/lib/External/isl/Makefile.am
+++ b/lib/External/isl/Makefile.am
@@ -498,6 +498,7 @@
 	bset_to_bmap.c \
 	bset_from_bmap.c \
 	isl_check_named_params_templ.c \
+	check_parse_fail_test_templ.c \
 	check_reparse_templ.c \
 	check_reparse_test_templ.c \
 	check_single_reference_templ.c \
diff --git a/lib/External/isl/Makefile.in b/lib/External/isl/Makefile.in
index 0abf9f2..a2e96d6 100644
--- a/lib/External/isl/Makefile.in
+++ b/lib/External/isl/Makefile.in
@@ -1398,6 +1398,7 @@
 	bset_to_bmap.c \
 	bset_from_bmap.c \
 	isl_check_named_params_templ.c \
+	check_parse_fail_test_templ.c \
 	check_reparse_templ.c \
 	check_reparse_test_templ.c \
 	check_single_reference_templ.c \
diff --git a/lib/External/isl/check_parse_fail_test_templ.c b/lib/External/isl/check_parse_fail_test_templ.c
new file mode 100644
index 0000000..6fba085
--- /dev/null
+++ b/lib/External/isl/check_parse_fail_test_templ.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2021      Cerebras Systems
+ *
+ * Use of this software is governed by the MIT license
+ *
+ * Written by Sven Verdoolaege,
+ * Cerebras Systems, 1237 E Arques Ave, Sunnyvale, CA, USA
+ */
+
+#define xCAT(A,B) A ## B
+#define CAT(A,B) xCAT(A,B)
+#undef TYPE
+#define TYPE CAT(isl_,BASE)
+#define xFN(TYPE,NAME) TYPE ## _ ## NAME
+#define FN(TYPE,NAME) xFN(TYPE,NAME)
+
+#undef TESTS
+#define TESTS CAT(parse_,CAT(BASE,_fail_tests))
+
+/* Test parsing of objects of type TYPE
+ * that are expected to fail.
+ */
+static isl_stat FN(check,TESTS)(isl_ctx *ctx)
+{
+	int i, n;
+	int on_error;
+
+	on_error = isl_options_get_on_error(ctx);
+	isl_options_set_on_error(ctx, ISL_ON_ERROR_CONTINUE);
+	n = ARRAY_SIZE(TESTS);
+	for (i = 0; i < n; ++i) {
+		TYPE *obj;
+
+		obj = FN(TYPE,read_from_str)(ctx, TESTS[i]);
+		FN(TYPE,free)(obj);
+		if (obj)
+			break;
+	}
+	isl_options_set_on_error(ctx, on_error);
+	if (i < n)
+		isl_die(ctx, isl_error_unknown,
+			"parsing not expected to succeed",
+			return isl_stat_error);
+
+	return isl_stat_ok;
+}
diff --git a/lib/External/isl/check_reparse_test_templ.c b/lib/External/isl/check_reparse_test_templ.c
index 58c194c..0a0740a 100644
--- a/lib/External/isl/check_reparse_test_templ.c
+++ b/lib/External/isl/check_reparse_test_templ.c
@@ -5,6 +5,7 @@
 #define xFN(TYPE,NAME) TYPE ## _ ## NAME
 #define FN(TYPE,NAME) xFN(TYPE,NAME)
 
+#undef TESTS
 #define TESTS CAT(reparse_,CAT(BASE,_tests))
 
 /* Test parsing of objects of type TYPE by printing
diff --git a/lib/External/isl/include/isl/aff.h b/lib/External/isl/include/isl/aff.h
index cfa0851..c417be1 100644
--- a/lib/External/isl/include/isl/aff.h
+++ b/lib/External/isl/include/isl/aff.h
@@ -212,6 +212,7 @@
 isl_ctx *isl_pw_aff_get_ctx(__isl_keep isl_pw_aff *pwaff);
 uint32_t isl_pw_aff_get_hash(__isl_keep isl_pw_aff *pa);
 __isl_give isl_space *isl_pw_aff_get_domain_space(__isl_keep isl_pw_aff *pwaff);
+__isl_export
 __isl_give isl_space *isl_pw_aff_get_space(__isl_keep isl_pw_aff *pwaff);
 
 __isl_constructor
diff --git a/lib/External/isl/include/isl/cpp-checked.h b/lib/External/isl/include/isl/cpp-checked.h
index 54417e0..bde60ad 100644
--- a/lib/External/isl/include/isl/cpp-checked.h
+++ b/lib/External/isl/include/isl/cpp-checked.h
@@ -1490,6 +1490,7 @@
   inline isl::checked::map_list map_list() const;
   inline isl::checked::multi_pw_aff max_multi_pw_aff() const;
   inline isl::checked::multi_pw_aff min_multi_pw_aff() const;
+  inline class size n_basic_map() const;
   inline isl::checked::basic_map polyhedral_hull() const;
   inline isl::checked::map preimage_domain(const isl::checked::multi_aff &ma) const;
   inline isl::checked::map preimage_domain(const isl::checked::multi_pw_aff &mpa) const;
@@ -1623,6 +1624,7 @@
   inline isl::checked::val max_val(const isl::checked::aff &obj) const;
   inline isl::checked::multi_pw_aff min_multi_pw_aff() const;
   inline isl::checked::val min_val(const isl::checked::aff &obj) const;
+  inline class size n_basic_set() const;
   inline isl::checked::basic_set params() const;
   inline isl::checked::multi_val plain_multi_val_if_fixed() const;
   inline isl::checked::basic_set polyhedral_hull() const;
@@ -1908,6 +1910,7 @@
   inline isl::checked::map_list map_list() const;
   inline isl::checked::multi_pw_aff max_multi_pw_aff() const;
   inline isl::checked::multi_pw_aff min_multi_pw_aff() const;
+  inline class size n_basic_map() const;
   inline isl::checked::basic_map polyhedral_hull() const;
   inline isl::checked::map preimage_domain(isl::checked::multi_aff ma) const;
   inline isl::checked::map preimage_domain(isl::checked::multi_pw_aff mpa) const;
@@ -2542,6 +2545,7 @@
   inline isl::checked::val min_val(const isl::checked::aff &obj) const;
   inline isl::checked::multi_val multi_val() const;
   inline isl::checked::multi_val get_multi_val() const;
+  inline class size n_basic_set() const;
   inline isl::checked::basic_set params() const;
   inline isl::checked::multi_val plain_multi_val_if_fixed() const;
   inline isl::checked::basic_set polyhedral_hull() const;
@@ -2719,6 +2723,7 @@
   inline isl::checked::pw_multi_aff set_range_tuple(const std::string &id) const;
   inline class size size() const;
   inline isl::checked::space space() const;
+  inline isl::checked::space get_space() const;
   inline isl::checked::multi_pw_aff sub(const isl::checked::multi_pw_aff &multi2) const;
   inline isl::checked::multi_union_pw_aff sub(const isl::checked::multi_union_pw_aff &multi2) const;
   inline isl::checked::pw_aff sub(isl::checked::pw_aff pwaff2) const;
@@ -3488,6 +3493,7 @@
   inline isl::checked::val max_val(const isl::checked::aff &obj) const;
   inline isl::checked::multi_pw_aff min_multi_pw_aff() const;
   inline isl::checked::val min_val(const isl::checked::aff &obj) const;
+  inline class size n_basic_set() const;
   inline isl::checked::set params() const;
   inline isl::checked::multi_val plain_multi_val_if_fixed() const;
   inline isl::checked::multi_val get_plain_multi_val_if_fixed() const;
@@ -4993,7 +4999,7 @@
 
 isl::checked::space aff::space() const
 {
-  return isl::checked::multi_aff(*this).space();
+  return isl::checked::pw_aff(*this).space();
 }
 
 isl::checked::aff aff::sub(isl::checked::aff aff2) const
@@ -7677,6 +7683,11 @@
   return isl::checked::map(*this).min_multi_pw_aff();
 }
 
+class size basic_map::n_basic_map() const
+{
+  return isl::checked::map(*this).n_basic_map();
+}
+
 isl::checked::basic_map basic_map::polyhedral_hull() const
 {
   return isl::checked::map(*this).polyhedral_hull();
@@ -8291,6 +8302,11 @@
   return isl::checked::set(*this).min_val(obj);
 }
 
+class size basic_set::n_basic_set() const
+{
+  return isl::checked::set(*this).n_basic_set();
+}
+
 isl::checked::basic_set basic_set::params() const
 {
   auto res = isl_basic_set_params(copy());
@@ -9534,6 +9550,12 @@
   return manage(res);
 }
 
+class size map::n_basic_map() const
+{
+  auto res = isl_map_n_basic_map(get());
+  return manage(res);
+}
+
 isl::checked::basic_map map::polyhedral_hull() const
 {
   auto res = isl_map_polyhedral_hull(copy());
@@ -12439,6 +12461,11 @@
   return multi_val();
 }
 
+class size point::n_basic_set() const
+{
+  return isl::checked::basic_set(*this).n_basic_set();
+}
+
 isl::checked::basic_set point::params() const
 {
   return isl::checked::basic_set(*this).params();
@@ -13290,7 +13317,13 @@
 
 isl::checked::space pw_aff::space() const
 {
-  return isl::checked::union_pw_aff(*this).space();
+  auto res = isl_pw_aff_get_space(get());
+  return manage(res);
+}
+
+isl::checked::space pw_aff::get_space() const
+{
+  return space();
 }
 
 isl::checked::multi_pw_aff pw_aff::sub(const isl::checked::multi_pw_aff &multi2) const
@@ -16217,6 +16250,12 @@
   return manage(res);
 }
 
+class size set::n_basic_set() const
+{
+  auto res = isl_set_n_basic_set(get());
+  return manage(res);
+}
+
 isl::checked::set set::params() const
 {
   auto res = isl_set_params(copy());
diff --git a/lib/External/isl/include/isl/cpp.h b/lib/External/isl/include/isl/cpp.h
index 0e7c6b9..42b5cb6 100644
--- a/lib/External/isl/include/isl/cpp.h
+++ b/lib/External/isl/include/isl/cpp.h
@@ -1555,6 +1555,7 @@
   inline isl::map_list map_list() const;
   inline isl::multi_pw_aff max_multi_pw_aff() const;
   inline isl::multi_pw_aff min_multi_pw_aff() const;
+  inline unsigned n_basic_map() const;
   inline isl::basic_map polyhedral_hull() const;
   inline isl::map preimage_domain(const isl::multi_aff &ma) const;
   inline isl::map preimage_domain(const isl::multi_pw_aff &mpa) const;
@@ -1688,6 +1689,7 @@
   inline isl::val max_val(const isl::aff &obj) const;
   inline isl::multi_pw_aff min_multi_pw_aff() const;
   inline isl::val min_val(const isl::aff &obj) const;
+  inline unsigned n_basic_set() const;
   inline isl::basic_set params() const;
   inline isl::multi_val plain_multi_val_if_fixed() const;
   inline isl::basic_set polyhedral_hull() const;
@@ -1973,6 +1975,7 @@
   inline isl::map_list map_list() const;
   inline isl::multi_pw_aff max_multi_pw_aff() const;
   inline isl::multi_pw_aff min_multi_pw_aff() const;
+  inline unsigned n_basic_map() const;
   inline isl::basic_map polyhedral_hull() const;
   inline isl::map preimage_domain(isl::multi_aff ma) const;
   inline isl::map preimage_domain(isl::multi_pw_aff mpa) const;
@@ -2607,6 +2610,7 @@
   inline isl::val min_val(const isl::aff &obj) const;
   inline isl::multi_val multi_val() const;
   inline isl::multi_val get_multi_val() const;
+  inline unsigned n_basic_set() const;
   inline isl::basic_set params() const;
   inline isl::multi_val plain_multi_val_if_fixed() const;
   inline isl::basic_set polyhedral_hull() const;
@@ -2784,6 +2788,7 @@
   inline isl::pw_multi_aff set_range_tuple(const std::string &id) const;
   inline unsigned size() const;
   inline isl::space space() const;
+  inline isl::space get_space() const;
   inline isl::multi_pw_aff sub(const isl::multi_pw_aff &multi2) const;
   inline isl::multi_union_pw_aff sub(const isl::multi_union_pw_aff &multi2) const;
   inline isl::pw_aff sub(isl::pw_aff pwaff2) const;
@@ -3553,6 +3558,7 @@
   inline isl::val max_val(const isl::aff &obj) const;
   inline isl::multi_pw_aff min_multi_pw_aff() const;
   inline isl::val min_val(const isl::aff &obj) const;
+  inline unsigned n_basic_set() const;
   inline isl::set params() const;
   inline isl::multi_val plain_multi_val_if_fixed() const;
   inline isl::multi_val get_plain_multi_val_if_fixed() const;
@@ -5416,7 +5422,7 @@
 {
   if (!ptr)
     exception::throw_invalid("NULL input", __FILE__, __LINE__);
-  return isl::multi_aff(*this).space();
+  return isl::pw_aff(*this).space();
 }
 
 isl::aff aff::sub(isl::aff aff2) const
@@ -8980,6 +8986,13 @@
   return isl::map(*this).min_multi_pw_aff();
 }
 
+unsigned basic_map::n_basic_map() const
+{
+  if (!ptr)
+    exception::throw_invalid("NULL input", __FILE__, __LINE__);
+  return isl::map(*this).n_basic_map();
+}
+
 isl::basic_map basic_map::polyhedral_hull() const
 {
   if (!ptr)
@@ -9896,6 +9909,13 @@
   return isl::set(*this).min_val(obj);
 }
 
+unsigned basic_set::n_basic_set() const
+{
+  if (!ptr)
+    exception::throw_invalid("NULL input", __FILE__, __LINE__);
+  return isl::set(*this).n_basic_set();
+}
+
 isl::basic_set basic_set::params() const
 {
   if (!ptr)
@@ -11875,6 +11895,18 @@
   return manage(res);
 }
 
+unsigned map::n_basic_map() const
+{
+  if (!ptr)
+    exception::throw_invalid("NULL input", __FILE__, __LINE__);
+  auto saved_ctx = ctx();
+  options_scoped_set_on_error saved_on_error(saved_ctx, exception::on_error);
+  auto res = isl_map_n_basic_map(get());
+  if (res < 0)
+    exception::throw_last_error(saved_ctx);
+  return res;
+}
+
 isl::basic_map map::polyhedral_hull() const
 {
   if (!ptr)
@@ -16592,6 +16624,13 @@
   return multi_val();
 }
 
+unsigned point::n_basic_set() const
+{
+  if (!ptr)
+    exception::throw_invalid("NULL input", __FILE__, __LINE__);
+  return isl::basic_set(*this).n_basic_set();
+}
+
 isl::basic_set point::params() const
 {
   if (!ptr)
@@ -17913,7 +17952,17 @@
 {
   if (!ptr)
     exception::throw_invalid("NULL input", __FILE__, __LINE__);
-  return isl::union_pw_aff(*this).space();
+  auto saved_ctx = ctx();
+  options_scoped_set_on_error saved_on_error(saved_ctx, exception::on_error);
+  auto res = isl_pw_aff_get_space(get());
+  if (!res)
+    exception::throw_last_error(saved_ctx);
+  return manage(res);
+}
+
+isl::space pw_aff::get_space() const
+{
+  return space();
 }
 
 isl::multi_pw_aff pw_aff::sub(const isl::multi_pw_aff &multi2) const
@@ -22502,6 +22551,18 @@
   return manage(res);
 }
 
+unsigned set::n_basic_set() const
+{
+  if (!ptr)
+    exception::throw_invalid("NULL input", __FILE__, __LINE__);
+  auto saved_ctx = ctx();
+  options_scoped_set_on_error saved_on_error(saved_ctx, exception::on_error);
+  auto res = isl_set_n_basic_set(get());
+  if (res < 0)
+    exception::throw_last_error(saved_ctx);
+  return res;
+}
+
 isl::set set::params() const
 {
   if (!ptr)
diff --git a/lib/External/isl/include/isl/map.h b/lib/External/isl/include/isl/map.h
index ede0463..55feb9b 100644
--- a/lib/External/isl/include/isl/map.h
+++ b/lib/External/isl/include/isl/map.h
@@ -698,6 +698,7 @@
 
 uint32_t isl_map_get_hash(__isl_keep isl_map *map);
 
+__isl_export
 isl_size isl_map_n_basic_map(__isl_keep isl_map *map);
 __isl_export
 isl_stat isl_map_foreach_basic_map(__isl_keep isl_map *map,
diff --git a/lib/External/isl/include/isl/set.h b/lib/External/isl/include/isl/set.h
index 4b66b82..3e9b224 100644
--- a/lib/External/isl/include/isl/set.h
+++ b/lib/External/isl/include/isl/set.h
@@ -512,6 +512,7 @@
 
 uint32_t isl_set_get_hash(__isl_keep isl_set *set);
 
+__isl_export
 isl_size isl_set_n_basic_set(__isl_keep isl_set *set);
 __isl_export
 isl_stat isl_set_foreach_basic_set(__isl_keep isl_set *set,
diff --git a/lib/External/isl/include/isl/typed_cpp.h b/lib/External/isl/include/isl/typed_cpp.h
index 165a61b..30c47eb 100644
--- a/lib/External/isl/include/isl/typed_cpp.h
+++ b/lib/External/isl/include/isl/typed_cpp.h
@@ -7235,6 +7235,7 @@
   template <typename Domain2>
   inline typed::pw_multi_aff<Domain2> set_range_tuple(const std::string &id) const;
   inline typed::space<Anonymous> space() const;
+  inline typed::space<Anonymous> get_space() const = delete;
   inline typed::multi_pw_aff<Anonymous> sub(const typed::multi_pw_aff<Anonymous> &multi2) const;
   inline typed::multi_union_pw_aff<Anonymous> sub(const typed::multi_union_pw_aff<Anonymous> &multi2) const;
   inline typed::pw_aff<Anonymous> sub(const typed::pw_aff<Anonymous> &pwaff2) const;
@@ -7448,6 +7449,7 @@
   template <typename Range2>
   inline typed::pw_multi_aff<Domain, Range2> set_range_tuple(const std::string &id) const;
   inline typed::space<Domain, Anonymous> space() const;
+  inline typed::space<Domain, Anonymous> get_space() const = delete;
   inline typed::multi_pw_aff<Domain, Anonymous> sub(const typed::multi_pw_aff<Domain, Anonymous> &multi2) const;
   inline typed::multi_union_pw_aff<Domain, Anonymous> sub(const typed::multi_union_pw_aff<Domain, Anonymous> &multi2) const;
   inline typed::pw_aff<Domain, Anonymous> sub(const typed::pw_aff<Domain, Anonymous> &pwaff2) const;
@@ -7663,6 +7665,7 @@
   template <typename Arg1>
   inline typed::pw_multi_aff<pair<Domain2, Range2>, Arg1> set_range_tuple(const std::string &id) const;
   inline typed::space<pair<Domain2, Range2>, Anonymous> space() const;
+  inline typed::space<pair<Domain2, Range2>, Anonymous> get_space() const = delete;
   inline typed::multi_pw_aff<pair<Domain2, Range2>, Anonymous> sub(const typed::multi_pw_aff<pair<Domain2, Range2>, Anonymous> &multi2) const;
   inline typed::multi_union_pw_aff<pair<Domain2, Range2>, Anonymous> sub(const typed::multi_union_pw_aff<pair<Domain2, Range2>, Anonymous> &multi2) const;
   inline typed::pw_aff<pair<Domain2, Range2>, Anonymous> sub(const typed::pw_aff<pair<Domain2, Range2>, Anonymous> &pwaff2) const;
diff --git a/lib/External/isl/interface/isl.py b/lib/External/isl/interface/isl.py
index 13a9514..f2249cb 100644
--- a/lib/External/isl/interface/isl.py
+++ b/lib/External/isl/interface/isl.py
@@ -3163,6 +3163,18 @@
             obj = pw_aff(ctx=ctx, ptr=res)
             return obj
         raise Error
+    def space(arg0):
+        try:
+            if not arg0.__class__ is pw_aff:
+                arg0 = pw_aff(arg0)
+        except:
+            raise
+        ctx = arg0.ctx
+        res = isl.isl_pw_aff_get_space(arg0.ptr)
+        obj = space(ctx=ctx, ptr=res)
+        return obj
+    def get_space(arg0):
+        return arg0.space()
     def sub(arg0, arg1):
         try:
             if not arg0.__class__ is pw_aff:
@@ -3334,6 +3346,8 @@
 isl.isl_pw_aff_scale_val.argtypes = [c_void_p, c_void_p]
 isl.isl_pw_aff_scale_down_val.restype = c_void_p
 isl.isl_pw_aff_scale_down_val.argtypes = [c_void_p, c_void_p]
+isl.isl_pw_aff_get_space.restype = c_void_p
+isl.isl_pw_aff_get_space.argtypes = [c_void_p]
 isl.isl_pw_aff_sub.restype = c_void_p
 isl.isl_pw_aff_sub.argtypes = [c_void_p, c_void_p]
 isl.isl_pw_aff_subtract_domain.restype = c_void_p
@@ -8635,6 +8649,17 @@
         res = isl.isl_map_min_multi_pw_aff(isl.isl_map_copy(arg0.ptr))
         obj = multi_pw_aff(ctx=ctx, ptr=res)
         return obj
+    def n_basic_map(arg0):
+        try:
+            if not arg0.__class__ is map:
+                arg0 = map(arg0)
+        except:
+            raise
+        ctx = arg0.ctx
+        res = isl.isl_map_n_basic_map(arg0.ptr)
+        if res < 0:
+            raise
+        return int(res)
     def polyhedral_hull(arg0):
         try:
             if not arg0.__class__ is map:
@@ -9072,6 +9097,7 @@
 isl.isl_map_max_multi_pw_aff.argtypes = [c_void_p]
 isl.isl_map_min_multi_pw_aff.restype = c_void_p
 isl.isl_map_min_multi_pw_aff.argtypes = [c_void_p]
+isl.isl_map_n_basic_map.argtypes = [c_void_p]
 isl.isl_map_polyhedral_hull.restype = c_void_p
 isl.isl_map_polyhedral_hull.argtypes = [c_void_p]
 isl.isl_map_preimage_domain_multi_aff.restype = c_void_p
@@ -10538,6 +10564,17 @@
         res = isl.isl_set_min_val(arg0.ptr, arg1.ptr)
         obj = val(ctx=ctx, ptr=res)
         return obj
+    def n_basic_set(arg0):
+        try:
+            if not arg0.__class__ is set:
+                arg0 = set(arg0)
+        except:
+            raise
+        ctx = arg0.ctx
+        res = isl.isl_set_n_basic_set(arg0.ptr)
+        if res < 0:
+            raise
+        return int(res)
     def params(arg0):
         try:
             if not arg0.__class__ is set:
@@ -10908,6 +10945,7 @@
 isl.isl_set_min_multi_pw_aff.argtypes = [c_void_p]
 isl.isl_set_min_val.restype = c_void_p
 isl.isl_set_min_val.argtypes = [c_void_p, c_void_p]
+isl.isl_set_n_basic_set.argtypes = [c_void_p]
 isl.isl_set_params.restype = c_void_p
 isl.isl_set_params.argtypes = [c_void_p]
 isl.isl_set_get_plain_multi_val_if_fixed.restype = c_void_p
diff --git a/lib/External/isl/interface/template_cpp.cc b/lib/External/isl/interface/template_cpp.cc
index bf13803..debbfcd 100644
--- a/lib/External/isl/interface/template_cpp.cc
+++ b/lib/External/isl/interface/template_cpp.cc
@@ -541,7 +541,7 @@
 static Signature map_from_domain_and_range =
 	{ { Domain, Range }, { { Domain }, { Range } } };
 
-/* Signatures for creating an anonymous set from a parameter set.
+/* Signatures for creating an anonymous set from a parameter set
  * or a map from a domain, where the range is anonymous.
  */
 static Signature anonymous_set_from_params = { { Anonymous }, { { } } };
@@ -592,7 +592,7 @@
  */
 static Signature map_reverse = { { Range, Domain }, { { Domain, Range } } };
 static Signature map_range_reverse =
-	{ { Domain, { Range, Range2} }, { { Domain, { Range2, Range} } } };
+	{ { Domain, { Range2, Range } }, { { Domain, { Range, Range2 } } } };
 
 /* Signatures for constructing products.
  */
@@ -850,10 +850,10 @@
 	{ "range_lattice_tile",	{ un_map } },
 	{ "range_map",		{ range_map } },
 	{ "range_product",	{ range_product } },
+	{ "range_reverse",	{ map_range_reverse } },
 	{ "range_simple_fixed_box_hull",
 				{ un_map } },
 	{ "reverse",		{ map_reverse } },
-	{ "range_reverse",	{ map_range_reverse } },
 	{ "scale",		bin_val },
 	{ "scale_down",		bin_val },
 	{ "set_at",		set_at },
diff --git a/lib/External/isl/isl_coalesce.c b/lib/External/isl/isl_coalesce.c
index e7cefa0..910c214 100644
--- a/lib/External/isl/isl_coalesce.c
+++ b/lib/External/isl/isl_coalesce.c
@@ -1526,6 +1526,9 @@
  * If "add_valid" is set, then the offending constraints are
  * simply removed.
  *
+ * If the facet turns out to be empty, then no wrapping can be performed.
+ * This is considered a failure, unless "add_valid" is set.
+ *
  * If any of the cut constraints of info->bmap turn out
  * to be redundant with respect to other constraints
  * then these will neither be wrapped nor added directly to the result.
@@ -1550,6 +1553,11 @@
 		return isl_stat_error;
 	if (isl_tab_detect_redundant(info->tab) < 0)
 		return isl_stat_error;
+	if (info->tab->empty) {
+		if (!add_valid)
+			return wraps_mark_failed(wraps);
+		return isl_stat_ok;
+	}
 	nowrap = has_redundant_cuts(info);
 	if (nowrap < 0)
 		return isl_stat_error;
diff --git a/lib/External/isl/isl_ctx_private.h b/lib/External/isl/isl_ctx_private.h
index 7c66f36..5083a96 100644
--- a/lib/External/isl/isl_ctx_private.h
+++ b/lib/External/isl/isl_ctx_private.h
@@ -42,3 +42,6 @@
 };
 
 int isl_ctx_next_operation(isl_ctx *ctx);
+
+void isl_ctx_set_full_error(isl_ctx *ctx, enum isl_error error, const char *msg,
+	const char *file, int line);
diff --git a/lib/External/isl/isl_input.c b/lib/External/isl/isl_input.c
index 4ac2bdd..4c6839d 100644
--- a/lib/External/isl/isl_input.c
+++ b/lib/External/isl/isl_input.c
@@ -509,7 +509,9 @@
 		aff = isl_aff_zero_on_domain(isl_local_space_from_space(isl_space_copy(space)));
 		if (!aff)
 			goto error;
-		isl_int_set_si(aff->v->el[2 + pos], 1);
+		aff->v = isl_vec_set_element_si(aff->v, 2 + pos, 1);
+		if (!aff->v)
+			aff = isl_aff_free(aff);
 		res = isl_pw_aff_from_aff(aff);
 		isl_token_free(tok);
 	} else if (tok->type == ISL_TOKEN_VALUE) {
@@ -3679,6 +3681,9 @@
  * through a call to extract_mpa_from_tuple.
  * The result is converted to an isl_pw_multi_aff and
  * its domain is intersected with the domain.
+ *
+ * Note that the last tuple may introduce new identifiers,
+ * but these cannot be referenced in the description of the domain.
  */
 static __isl_give isl_pw_multi_aff *read_conditional_multi_aff(
 	__isl_keep isl_stream *s, __isl_take isl_set *dom, struct vars *v)
@@ -3687,13 +3692,16 @@
 	isl_multi_pw_aff *mpa;
 	isl_pw_multi_aff *pma;
 	int n = v->n;
+	int n_dom;
 
+	n_dom = v->n;
 	tuple = read_tuple(s, v, 0, 0);
 	if (!tuple)
 		goto error;
 	if (isl_stream_eat_if_available(s, ISL_TOKEN_TO)) {
 		isl_map *map = map_from_tuple(tuple, dom, isl_dim_in, v, 0);
 		dom = isl_map_domain(map);
+		n_dom = v->n;
 		tuple = read_tuple(s, v, 0, 0);
 		if (!tuple)
 			goto error;
@@ -3703,6 +3711,7 @@
 	if (!mpa)
 		dom = isl_set_free(dom);
 
+	vars_drop(v, v->n - n_dom);
 	dom = read_optional_formula(s, dom, v, 0);
 
 	vars_drop(v, v->n - n);
@@ -3987,10 +3996,14 @@
  * is then converted into the isl_multi_pw_aff through a call
  * to extract_mpa_from_tuple and the domain of the result
  * is intersected with the domain.
+ *
+ * Note that the last tuple may introduce new identifiers,
+ * but these cannot be referenced in the description of the domain.
  */
 __isl_give isl_multi_pw_aff *isl_stream_read_multi_pw_aff(
 	__isl_keep isl_stream *s)
 {
+	int n_dom;
 	struct vars *v;
 	isl_set *dom = NULL;
 	isl_multi_pw_aff *tuple = NULL;
@@ -4009,17 +4022,20 @@
 	if (isl_stream_eat(s, '{'))
 		goto error;
 
+	n_dom = v->n;
 	tuple = read_tuple(s, v, 0, 0);
 	if (!tuple)
 		goto error;
 	if (isl_stream_eat_if_available(s, ISL_TOKEN_TO)) {
 		isl_map *map = map_from_tuple(tuple, dom, isl_dim_in, v, 0);
 		dom = isl_map_domain(map);
+		n_dom = v->n;
 		tuple = read_tuple(s, v, 0, 0);
 		if (!tuple)
 			goto error;
 	}
 
+	vars_drop(v, v->n - n_dom);
 	if (isl_stream_eat_if_available(s, ':'))
 		dom = read_formula(s, v, dom, 0);
 
diff --git a/lib/External/isl/isl_scheduler.c b/lib/External/isl/isl_scheduler.c
index 0108811..5ab65d2 100644
--- a/lib/External/isl/isl_scheduler.c
+++ b/lib/External/isl/isl_scheduler.c
@@ -1106,7 +1106,7 @@
  * If any of the sizes turns out to be zero, then this means
  * that this dimension has a fixed value in terms of
  * the other dimensions.  Perform an (extra) compression
- * to remove this dimensions.
+ * to remove this dimension.
  */
 static isl_stat compute_sizes(struct isl_sched_node *node,
 	__isl_keep isl_set *uncompressed)
diff --git a/lib/External/isl/isl_stream.c b/lib/External/isl/isl_stream.c
index 5f2732b..1052360 100644
--- a/lib/External/isl/isl_stream.c
+++ b/lib/External/isl/isl_stream.c
@@ -9,11 +9,12 @@
 
 #include <ctype.h>
 #include <string.h>
-#include <isl/ctx.h>
+#include <isl_ctx_private.h>
 #include <isl_stream_private.h>
 #include <isl/map.h>
 #include <isl/aff.h>
 #include <isl_val_private.h>
+#include <isl_options_private.h>
 
 struct isl_keyword {
 	char			*name;
@@ -134,6 +135,12 @@
 {
 	int line = tok ? tok->line : s->line;
 	int col = tok ? tok->col : s->col;
+
+	isl_ctx_set_full_error(s->ctx, isl_error_invalid, "syntax error",
+				__FILE__, __LINE__);
+
+	if (s->ctx->opt->on_error == ISL_ON_ERROR_CONTINUE)
+		return;
 	fprintf(stderr, "syntax error (%d, %d): %s\n", line, col, msg);
 	if (tok) {
 		if (tok->type < 256)
@@ -165,6 +172,8 @@
 		else
 			fprintf(stderr, "got token type %d\n", tok->type);
 	}
+	if (s->ctx->opt->on_error == ISL_ON_ERROR_ABORT)
+		abort();
 }
 
 static __isl_give isl_stream* isl_stream_new(struct isl_ctx *ctx)
diff --git a/lib/External/isl/isl_test.c b/lib/External/isl/isl_test.c
index 4d82f1e..2d09650 100644
--- a/lib/External/isl/isl_test.c
+++ b/lib/External/isl/isl_test.c
@@ -135,6 +135,8 @@
 	"[N] -> { [N] : N >= 0 }",
 	"[N] -> { [N, N + 1] : N >= 0 }",
 	"[N, M] -> { [(N : N >= 0), (M : M >= 0)] : N + M >= 0 }",
+	"{ [a] -> [b = a] }",
+	"{ [a] -> [b = a] : a >= 0 }",
 };
 
 #undef BASE
@@ -143,6 +145,16 @@
 #include "check_reparse_templ.c"
 #include "check_reparse_test_templ.c"
 
+/* String descriptions that cannot be parsed
+ * as multi piecewise affine expressions.
+ */
+static const char *parse_multi_pw_aff_fail_tests[] = {
+	"{ [a] -> [b] : b = a }",
+	"{ [a] -> [b = a] : b >= 0 }",
+};
+
+#include "check_parse_fail_test_templ.c"
+
 /* String descriptions of piecewise multi affine expressions
  * that are used for testing printing and parsing.
  */
@@ -184,6 +196,31 @@
 	return isl_stat_ok;
 }
 
+/* String descriptions that cannot be parsed
+ * as union piecewise multi affine expressions.
+ */
+static const char *parse_union_pw_multi_aff_fail_tests[] = {
+	"{ [a] -> [b] : b = a }",
+	"{ [a] -> [b = a] : b >= 0 }",
+};
+
+#undef BASE
+#define BASE union_pw_multi_aff
+
+#include "check_parse_fail_test_templ.c"
+
+/* Test parsing of union piecewise multi affine expressions.
+ *
+ * In particular, check some cases where parsing is supposed to fail.
+ */
+static isl_stat test_parse_upma(isl_ctx *ctx)
+{
+	if (check_parse_union_pw_multi_aff_fail_tests(ctx) < 0)
+		return isl_stat_error;
+
+	return isl_stat_ok;
+}
+
 /* Test parsing of multi piecewise affine expressions by printing
  * the expressions and checking that parsing the output results
  * in the same expression.
@@ -191,6 +228,8 @@
  * an expression converted from a map with an output dimension name
  * that is equal to an automatically generated name, and
  * a set of expressions parsed from strings.
+ *
+ * Additionally, check some cases where parsing is supposed to fail.
  */
 static int test_parse_mpa(isl_ctx *ctx)
 {
@@ -227,6 +266,8 @@
 
 	if (check_reparse_multi_pw_aff_tests(ctx) < 0)
 		return -1;
+	if (check_parse_multi_pw_aff_fail_tests(ctx) < 0)
+		return -1;
 
 	return 0;
 }
@@ -418,6 +459,8 @@
 		return -1;
 	if (test_parse_pma(ctx) < 0)
 		return -1;
+	if (test_parse_upma(ctx) < 0)
+		return -1;
 
 	str = "{ [i] -> [-i] }";
 	map = isl_map_read_from_str(ctx, str);
@@ -2375,30 +2418,43 @@
 	return 0;
 }
 
-/* A specialized coalescing test case that would result in an assertion
- * in an earlier version of isl.
+/* Check that the union of the basic sets described by "str1" and "str2"
+ * can be coalesced.
  * The explicit call to isl_basic_set_union prevents the implicit
- * equality constraints in the first basic map from being detected prior
+ * equality constraints in the basic maps from being detected prior
  * to the call to isl_set_coalesce, at least at the point
- * where this test case was introduced.
+ * where this function was introduced.
  */
-static int test_coalesce_special2(struct isl_ctx *ctx)
+static isl_stat test_coalesce_union(isl_ctx *ctx, const char *str1,
+	const char *str2)
 {
-	const char *str;
 	isl_basic_set *bset1, *bset2;
 	isl_set *set;
 
-	str = "{ [x, y] : x, y >= 0 and x + 2y <= 1 and 2x + y <= 1 }";
-	bset1 = isl_basic_set_read_from_str(ctx, str);
-	str = "{ [x,0] : -1 <= x <= 1 and x mod 2 = 1 }" ;
-	bset2 = isl_basic_set_read_from_str(ctx, str);
+	bset1 = isl_basic_set_read_from_str(ctx, str1);
+	bset2 = isl_basic_set_read_from_str(ctx, str2);
 	set = isl_basic_set_union(bset1, bset2);
 	set = isl_set_coalesce(set);
 	isl_set_free(set);
 
-	if (!set)
-		return -1;
-	return 0;
+	return isl_stat_non_null(set);
+}
+
+/* A specialized coalescing test case that would result in an assertion
+ * in an earlier version of isl.  Use test_coalesce_union with
+ * an explicit call to isl_basic_set_union to prevent the implicit
+ * equality constraints in the first basic map from being detected prior
+ * to the call to isl_set_coalesce, at least at the point
+ * where this test case was introduced.
+ */
+static isl_stat test_coalesce_special2(struct isl_ctx *ctx)
+{
+	const char *str1;
+	const char *str2;
+
+	str1 = "{ [x, y] : x, y >= 0 and x + 2y <= 1 and 2x + y <= 1 }";
+	str2 = "{ [x,0] : -1 <= x <= 1 and x mod 2 = 1 }";
+	return test_coalesce_union(ctx, str1, str2);
 }
 
 /* Check that calling isl_set_coalesce does not leave other sets
@@ -2510,6 +2566,25 @@
 	return test_coalesce_intersection(ctx, s1, s2);
 }
 
+/* A specialized coalescing test case that would result in an assertion failure
+ * in an earlier version of isl.  Use test_coalesce_union with
+ * an explicit call to isl_basic_set_union to prevent the implicit
+ * equality constraints in the basic maps from being detected prior
+ * to the call to isl_set_coalesce, at least at the point
+ * where this test case was introduced.
+ */
+static isl_stat test_coalesce_special7(isl_ctx *ctx)
+{
+	const char *str1;
+	const char *str2;
+
+	str1 = "{ [a, b, c=0:17] : a <= 7 and 2b <= 11 - a and "
+			"c <= -7 + 2a and 2c >= - 3 + 3a - 2b }";
+	str2 = "{ [a, b, c] : c > -15a and c >= -7 + 2a and c < 0 and "
+			"3c <= -5 + 5a - 3b and 2b >= 11 - a }";
+	return test_coalesce_union(ctx, str1, str2);
+}
+
 /* Test the functionality of isl_set_coalesce.
  * That is, check that the output is always equal to the input
  * and in some cases that the result consists of a single disjunct.
@@ -2539,6 +2614,8 @@
 		return -1;
 	if (test_coalesce_special6(ctx) < 0)
 		return -1;
+	if (test_coalesce_special7(ctx) < 0)
+		return -1;
 
 
 	return 0;
diff --git a/lib/External/isl/test_inputs/schedule/niewang.sc b/lib/External/isl/test_inputs/schedule/niewang.sc
index 776f2e8..816cd23 100644
--- a/lib/External/isl/test_inputs/schedule/niewang.sc
+++ b/lib/External/isl/test_inputs/schedule/niewang.sc
@@ -1,4 +1,4 @@
-# In earlier version of isl, this test case would take an inordinate
+# In earlier versions of isl, this test case would take an inordinate
 # amount of time (in the order of 30s versus 0.1s in later versions)
 # due to a call to isl_basic_set_coefficients.
 # Check that this no longer happens in the sense that this test case
diff --git a/test/JSONExporter/ImportAccesses/ImportAccesses-Bad-relation.ll b/test/JSONExporter/ImportAccesses/ImportAccesses-Bad-relation.ll
index 1d4fdbd..005564c 100644
--- a/test/JSONExporter/ImportAccesses/ImportAccesses-Bad-relation.ll
+++ b/test/JSONExporter/ImportAccesses/ImportAccesses-Bad-relation.ll
@@ -1,6 +1,6 @@
 ; RUN: not --crash opt %loadPolly -polly-import-jscop -polly-ast -polly-ast-detect-parallel  < %s 2>&1 >/dev/null | FileCheck %s
 ;
-; CHECK: The access was not parsed successfully by ISL.
+; CHECK: expecting other token
 ;
 ; Verify that the JSONImporter checks if the relation is valid.
 ;
diff --git a/test/JSONExporter/ImportContext/ImportContext-Unvalid-Context.ll b/test/JSONExporter/ImportContext/ImportContext-Unvalid-Context.ll
index 9dd481d..6f36326 100644
--- a/test/JSONExporter/ImportContext/ImportContext-Unvalid-Context.ll
+++ b/test/JSONExporter/ImportContext/ImportContext-Unvalid-Context.ll
@@ -1,6 +1,6 @@
 ; RUN: not --crash opt %loadPolly -polly-import-jscop -polly-ast -polly-ast-detect-parallel < %s 2>&1 >/dev/null | FileCheck %s
 ;
-; CHECK: The context was not parsed successfully by ISL.
+; CHECK: unexpected isl_token
 ;
 ; Verify if the JSONImporter check if the context is parsed successfully.
 ;
diff --git a/test/JSONExporter/ImportSchedule/ImportSchedule-Schedule-not-valid.ll b/test/JSONExporter/ImportSchedule/ImportSchedule-Schedule-not-valid.ll
index 8071808..76cfd10 100644
--- a/test/JSONExporter/ImportSchedule/ImportSchedule-Schedule-not-valid.ll
+++ b/test/JSONExporter/ImportSchedule/ImportSchedule-Schedule-not-valid.ll
@@ -1,6 +1,6 @@
 ; RUN: not --crash opt %loadPolly -polly-import-jscop -polly-ast -polly-ast-detect-parallel < %s 2>&1 >/dev/null | FileCheck %s
 ;
-; CHECK: The schedule was not parsed successfully (index = 1).
+; CHECK: expecting other token
 ;
 ; Verify if the JSONImporter check if the parsed schedule is valid.
 ;