Index: include/llvm/Analysis/VectorUtils.h
===================================================================
--- include/llvm/Analysis/VectorUtils.h
+++ include/llvm/Analysis/VectorUtils.h
@@ -262,7 +262,13 @@
   bool insertMember(InstTy *Instr, int Index, unsigned NewAlign) {
     assert(NewAlign && "The new member's alignment should be non-zero");
 
-    int Key = Index + SmallestKey;
+    // Make sure the key fits in an int.
+    long long KeyLong =
+        static_cast<long long>(Index) + static_cast<long long>(SmallestKey);
+    if (KeyLong > std::numeric_limits<int>::max() ||
+        KeyLong < std::numeric_limits<int>::min())
+      return false;
+    int Key = KeyLong;
 
     // Skip if there is already a member with the same index.
     if (Members.find(Key) != Members.end())
Index: test/Transforms/LoopVectorize/X86/interleaved-accesses-large-gap.ll
===================================================================
--- /dev/null
+++ test/Transforms/LoopVectorize/X86/interleaved-accesses-large-gap.ll
@@ -0,0 +1,38 @@
+; RUN: opt < %s  -loop-vectorize -mtriple x86_64 -S | FileCheck %s
+
+%struct.ST4 = type { i32, i32, i32, i32 }
+
+; The gaps between the memory access in this function are too large for
+; interleaving.
+; CHECK-LABEL: @test
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label %for.body
+
+; CHECK-LABEL: for.body:
+; CHECK: store i32
+; CHECK: store i32
+; CHECK: store i32
+; CHECK: store i32
+; CHECK-NOT: store
+define void @test(%struct.ST4* noalias %B) {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %for.body, %entry
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
+  %p1 = getelementptr inbounds %struct.ST4, %struct.ST4* %B, i64 %indvars.iv, i32 0
+  store i32 65536, i32* %p1, align 4
+  %p2 = getelementptr i32, i32* %p1, i32 -2147483648
+  store i32 65536, i32* %p2, align 4
+  %p3 = getelementptr inbounds %struct.ST4, %struct.ST4* %B, i64 %indvars.iv, i32 2
+  store i32 10, i32* %p3, align 4
+  %p4 = getelementptr inbounds %struct.ST4, %struct.ST4* %B, i64 %indvars.iv, i32 3
+  store i32 12, i32* %p4, align 4
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
+  %exitcond = icmp eq i64 %indvars.iv.next, 1024
+  br i1 %exitcond, label %for.cond.cleanup, label %for.body
+
+for.cond.cleanup:                                 ; preds = %for.body
+  ret void
+
+}