diff --git a/lib/CodeGen/MachineFunctionPass.cpp b/lib/CodeGen/MachineFunctionPass.cpp
new file mode 100644
index 0000000..09f156a
--- /dev/null
+++ b/lib/CodeGen/MachineFunctionPass.cpp
@@ -0,0 +1,52 @@
+//===-- MachineFunctionPass.cpp -------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the definitions of the MachineFunctionPass members.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/ScalarEvolution.h"
+#include "llvm/Analysis/IVUsers.h"
+#include "llvm/Analysis/LiveValues.h"
+#include "llvm/Analysis/LoopDependenceAnalysis.h"
+#include "llvm/Analysis/MemoryDependenceAnalysis.h"
+#include "llvm/CodeGen/MachineFunctionAnalysis.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+using namespace llvm;
+
+bool MachineFunctionPass::runOnFunction(Function &F) {
+  // Do not codegen any 'available_externally' functions at all, they have
+  // definitions outside the translation unit.
+  if (F.hasAvailableExternallyLinkage())
+    return false;
+
+  MachineFunction &MF = getAnalysis<MachineFunctionAnalysis>().getMF();
+  return runOnMachineFunction(MF);
+}
+
+void MachineFunctionPass::getAnalysisUsage(AnalysisUsage &AU) const {
+  AU.addRequired<MachineFunctionAnalysis>();
+  AU.addPreserved<MachineFunctionAnalysis>();
+
+  // MachineFunctionPass preserves all LLVM IR passes, but there's no
+  // high-level way to express this. Instead, just list a bunch of
+  // passes explicitly.
+  AU.addPreserved<AliasAnalysis>();
+  AU.addPreserved<ScalarEvolution>();
+  AU.addPreserved<IVUsers>();
+  AU.addPreserved<LoopDependenceAnalysis>();
+  AU.addPreserved<MemoryDependenceAnalysis>();
+  AU.addPreserved<LiveValues>();
+  AU.addPreserved<DominatorTree>();
+  AU.addPreserved<DominanceFrontier>();
+  AU.addPreserved<LoopInfo>();
+
+  FunctionPass::getAnalysisUsage(AU);
+}