diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 10dcc09c8ec..c87e4bf716a 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -459,7 +459,8 @@ void SelectionDAGISel::ShrinkDemandedOps() {
     SDNode *N = Worklist.pop_back_val();
 
     if (N->use_empty() && N != CurDAG->getRoot().getNode()) {
-      CurDAG->DeleteNode(N);
+      if (N->getOpcode() != ISD::DELETED_NODE)
+        CurDAG->DeleteNode(N);
       continue;
     }
 
diff --git a/test/CodeGen/X86/2010-01-07-ISelBug.ll b/test/CodeGen/X86/2010-01-07-ISelBug.ll
new file mode 100644
index 00000000000..081fab7facf
--- /dev/null
+++ b/test/CodeGen/X86/2010-01-07-ISelBug.ll
@@ -0,0 +1,27 @@
+; RUN: llc < %s -mtriple=x86_64-apple-darwin10
+; rdar://r7519827
+
+define i32 @t() nounwind ssp {
+entry:
+  br label %if.end.i11
+
+if.end.i11:                                       ; preds = %lor.lhs.false.i10, %lor.lhs.false.i10, %lor.lhs.false.i10
+  br i1 undef, label %for.body161, label %for.end197
+
+for.body161:                                      ; preds = %if.end.i11
+  br label %for.end197
+
+for.end197:                                       ; preds = %for.body161, %if.end.i11
+  %mlucEntry.4 = phi i96 [ undef, %for.body161 ], [ undef, %if.end.i11 ] ; <i96> [#uses=2]
+  store i96 %mlucEntry.4, i96* undef, align 8
+  %tmp172 = lshr i96 %mlucEntry.4, 64             ; <i96> [#uses=1]
+  %tmp173 = trunc i96 %tmp172 to i32              ; <i32> [#uses=1]
+  %tmp1.i1.i = call i32 @llvm.bswap.i32(i32 %tmp173) nounwind ; <i32> [#uses=1]
+  store i32 %tmp1.i1.i, i32* undef, align 8
+  unreachable
+
+if.then283:                                       ; preds = %lor.lhs.false.i10, %do.end105, %for.end
+  ret i32 undef
+}
+
+declare i32 @llvm.bswap.i32(i32) nounwind readnone