Index: llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
===================================================================
--- llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
+++ llvm/lib/Transforms/Utils/LoopUnrollAndJam.cpp
@@ -831,6 +831,22 @@
     if (SubLoopsSize != 1)
       return false;
 
+    // If the Loop has multiple exit blocks OR does not have an exit block,
+    // cannot perform unroll and jam
+    if (!L->getExitBlock()) {
+      LLVM_DEBUG(dbgs() << "Won't unroll-and-jam; Loop has multiple exit "
+                           "blocks OR does not have an exit block\n");
+      return false;
+    }
+
+    // If the Loop has multiple exiting blocks OR does not have an exiting
+    // blocks, cannot perform unroll and jam
+    if (!L->getExitingBlock()) {
+      LLVM_DEBUG(dbgs() << "Won't unroll-and-jam; Loop has multiple exiting "
+                           "blocks OR does not have an exiting block\n");
+      return false;
+    }
+
     L = L->getSubLoops()[0];
   } while (L);
 
Index: llvm/test/Transforms/LoopUnrollAndJam/multiple_exit_blocks.ll
===================================================================
--- /dev/null
+++ llvm/test/Transforms/LoopUnrollAndJam/multiple_exit_blocks.ll
@@ -0,0 +1,58 @@
+; REQUIRES: asserts
+; RUN: opt -debug-only=loop-unroll-and-jam -passes="loop-unroll-and-jam" -enable-unroll-and-jam -allow-unroll-and-jam -unroll-and-jam-count=8 -disable-output %s 2>&1 | FileCheck %s
+
+; CHECK: Loop Unroll and Jam: F[h] Loop %bb8
+; CHECK: Won't unroll-and-jam; Loop has multiple exit blocks OR does not have an exit block
+
+@a = external global i16, align 2
+@e = external global i32, align 4
+@f = external global i16, align 2
+@b = external global i16, align 2
+@c = external global i64, align 8
+
+define i16 @g() {
+bb:
+  %i = load i16, i16* @a, align 2
+  ret i16 %i
+}
+
+define void @h() {
+bb:
+  store i32 4, i32* @e, align 4
+  %i15 = load i16, i16* @b, align 2
+  %i17 = icmp slt i16 %i15, 1
+  br label %bb8
+
+bb8:                                              ; preds = %bb, %bb47
+  %storemerge15 = phi i32 [ 4, %bb ], [ %i49, %bb47 ]
+  br label %bb24
+
+bb24:                                             ; preds = %bb43, %bb8
+  %storemerge312 = phi i16 [ 0, %bb8 ], [ %i45, %bb43 ]
+  br i1 %i17, label %bb46.preheader, label %bb43
+
+bb46.preheader:                                   ; preds = %bb24
+  store i16 %storemerge312, i16* @f, align 2
+  br label %bb46
+
+bb43:                                             ; preds = %bb24
+  %i45 = add nuw nsw i16 %storemerge312, 1
+  %i13 = icmp ult i16 %storemerge312, 7
+  br i1 %i13, label %bb24, label %bb47
+
+bb46:                                             ; preds = %bb46.preheader, %bb46
+  br label %bb46
+
+bb47:                                             ; preds = %bb43
+  %i49 = add nsw i32 %storemerge15, -1
+  store i32 %i49, i32* @e, align 4
+  %i7.not = icmp eq i32 %i49, 0
+  br i1 %i7.not, label %bb50, label %bb8
+
+bb50:                                             ; preds = %bb47
+  store i16 %i45, i16* @f, align 2
+  ret void
+}
+
+; Function Attrs: argmemonly nofree nosync nounwind willreturn
+declare void @llvm.lifetime.start.p0i8(i64 immarg, i8* nocapture)