Index: lib/Analysis/ScopInfo.cpp
===================================================================
--- lib/Analysis/ScopInfo.cpp
+++ lib/Analysis/ScopInfo.cpp
@@ -86,6 +86,11 @@
                                       cl::Hidden, cl::ZeroOrMore,
                                       cl::init(true), cl::cat(PollyCategory));
 
+static cl::opt<bool> AllowUnbounded("polly-allow-unbounded",
+                                    cl::desc("Allow unbounded loops"),
+                                    cl::Hidden, cl::ZeroOrMore, cl::init(false),
+                                    cl::cat(PollyCategory));
+
 // Create a sequence of two schedules. Either argument may be null and is
 // interpreted as the empty schedule. Can also return null if both schedules are
 // empty.
@@ -903,9 +908,15 @@
       isl_set *UpperBoundSet = isl_pw_aff_le_set(IV, UpperBound);
       Domain = isl_set_intersect(Domain, UpperBoundSet);
     } else {
-      // If SCEV cannot provide a loop trip count we compute it with ISL.
+      // If SCEV cannot provide a loop trip count, we compute it with ISL. If
+      // the domain remains unbounded, make the assumed context infeasible
+      // unless we explicitly allow unbounded loops. Code generation currently
+      // does not expect unbounded loops.
       addLoopTripCountToDomain(L);
       isl_pw_aff_free(IV);
+      if (!AllowUnbounded)
+        if (!isl_set_dim_has_upper_bound(Domain, isl_dim_set, i))
+          Parent.addAssumption(isl_set_empty(Parent.getParamSpace()));
     }
   }
 
Index: test/ScopInfo/isl_trip_count_02.ll
===================================================================
--- test/ScopInfo/isl_trip_count_02.ll
+++ test/ScopInfo/isl_trip_count_02.ll
@@ -1,4 +1,4 @@
-; RUN: opt %loadPolly -polly-detect-unprofitable -polly-allow-non-scev-backedge-taken-count -polly-scops -analyze < %s | FileCheck %s
+; RUN: opt %loadPolly -polly-detect-unprofitable -polly-allow-non-scev-backedge-taken-count -polly-allow-unbounded -polly-scops -analyze < %s | FileCheck %s
 ;
 ; CHECK: [M, N] -> { Stmt_for_body[i0] : i0 >= 0 and N <= -1 + M };
 ;