diff --git a/llvm/include/llvm/LTO/LTO.h b/llvm/include/llvm/LTO/LTO.h
--- a/llvm/include/llvm/LTO/LTO.h
+++ b/llvm/include/llvm/LTO/LTO.h
@@ -191,8 +191,13 @@
 /// destructor.
 class NativeObjectStream {
 public:
-  NativeObjectStream(std::unique_ptr<raw_pwrite_stream> OS) : OS(std::move(OS)) {}
-  std::unique_ptr<raw_pwrite_stream> OS;
+  NativeObjectStream(std::unique_ptr<raw_pwrite_stream> OS)
+      : OS_(std::move(OS)) {
+    this->OS = &*this->OS_;
+  }
+  NativeObjectStream(raw_pwrite_stream *OS) : OS(OS) {}
+  std::unique_ptr<raw_pwrite_stream> OS_;
+  raw_pwrite_stream *OS;
   virtual ~NativeObjectStream() = default;
 };
 
diff --git a/llvm/lib/LTO/Caching.cpp b/llvm/lib/LTO/Caching.cpp
--- a/llvm/lib/LTO/Caching.cpp
+++ b/llvm/lib/LTO/Caching.cpp
@@ -85,7 +85,8 @@
 
       ~CacheStream() {
         // Make sure the stream is closed before committing it.
-        OS.reset();
+        OS_.reset();
+        OS = nullptr;
 
         // Open the file first to avoid racing with a cache pruner.
         ErrorOr<std::unique_ptr<MemoryBuffer>> MBOrErr =
diff --git a/llvm/lib/LTO/LTOCodeGenerator.cpp b/llvm/lib/LTO/LTOCodeGenerator.cpp
--- a/llvm/lib/LTO/LTOCodeGenerator.cpp
+++ b/llvm/lib/LTO/LTOCodeGenerator.cpp
@@ -37,6 +37,7 @@
 #include "llvm/IR/Verifier.h"
 #include "llvm/InitializePasses.h"
 #include "llvm/LTO/LTO.h"
+#include "llvm/LTO/LTOBackend.h"
 #include "llvm/LTO/legacy/LTOModule.h"
 #include "llvm/LTO/legacy/UpdateCompilerUsed.h"
 #include "llvm/Linker/Linker.h"
@@ -123,43 +124,10 @@
       TheLinker(new Linker(*MergedModule)) {
   Context.setDiscardValueNames(LTODiscardValueNames);
   Context.enableDebugTypeODRUniquing();
-  initializeLTOPasses();
 }
 
 LTOCodeGenerator::~LTOCodeGenerator() {}
 
-// Initialize LTO passes. Please keep this function in sync with
-// PassManagerBuilder::populateLTOPassManager(), and make sure all LTO
-// passes are initialized.
-void LTOCodeGenerator::initializeLTOPasses() {
-  PassRegistry &R = *PassRegistry::getPassRegistry();
-
-  initializeInternalizeLegacyPassPass(R);
-  initializeIPSCCPLegacyPassPass(R);
-  initializeGlobalOptLegacyPassPass(R);
-  initializeConstantMergeLegacyPassPass(R);
-  initializeDAHPass(R);
-  initializeInstructionCombiningPassPass(R);
-  initializeSimpleInlinerPass(R);
-  initializePruneEHPass(R);
-  initializeGlobalDCELegacyPassPass(R);
-  initializeOpenMPOptLegacyPassPass(R);
-  initializeArgPromotionPass(R);
-  initializeJumpThreadingPass(R);
-  initializeSROALegacyPassPass(R);
-  initializeAttributorLegacyPassPass(R);
-  initializeAttributorCGSCCLegacyPassPass(R);
-  initializePostOrderFunctionAttrsLegacyPassPass(R);
-  initializeReversePostOrderFunctionAttrsLegacyPassPass(R);
-  initializeGlobalsAAWrapperPassPass(R);
-  initializeLegacyLICMPassPass(R);
-  initializeMergedLoadStoreMotionLegacyPassPass(R);
-  initializeGVNLegacyPassPass(R);
-  initializeMemCpyOptLegacyPassPass(R);
-  initializeDCELegacyPassPass(R);
-  initializeCFGSimplifyPassPass(R);
-}
-
 void LTOCodeGenerator::setAsmUndefinedRefs(LTOModule *Mod) {
   const std::vector<StringRef> &undefs = Mod->getAsmUndefinedRefs();
   for (int i = 0, e = undefs.size(); i != e; ++i)
@@ -283,7 +251,24 @@
   // generate object file
   ToolOutputFile objFile(Filename, FD);
 
-  bool genResult = compileOptimized(&objFile.os());
+  lto::Config Conf;
+  Conf.CodeGenOnly = true;
+  Conf.OptLevel = OptLevel;
+  Conf.CGOptLevel = CGOptLevel;
+  Conf.Freestanding = Freestanding;
+
+  ModuleSummaryIndex CombinedIndex(false);
+  auto AddStream =
+      [&](size_t Task) -> std::unique_ptr<lto::NativeObjectStream> {
+    auto X = std::make_unique<lto::NativeObjectStream>(&objFile.os());
+    return X;
+  };
+
+  bool genResult = true;
+
+  if (Error Err =
+          backend(Conf, AddStream, 1, std::move(MergedModule), CombinedIndex))
+    genResult = false;
   objFile.os().close();
   if (objFile.os().has_error()) {
     emitError((Twine("could not write object file: ") + Filename + ": " +
@@ -574,34 +559,37 @@
   // Write LTOPostLink flag for passes that require all the modules.
   MergedModule->addModuleFlag(Module::Error, "LTOPostLink", 1);
 
-  // Instantiate the pass manager to organize the passes.
-  legacy::PassManager passes;
-
   // Add an appropriate DataLayout instance for this module...
   MergedModule->setDataLayout(TargetMach->createDataLayout());
 
-  passes.add(
-      createTargetTransformInfoWrapperPass(TargetMach->getTargetIRAnalysis()));
+  // TODO
+  // PMB.DisableGVNLoadPRE = DisableGVNLoadPRE;
 
-  Triple TargetTriple(TargetMach->getTargetTriple());
-  PassManagerBuilder PMB;
-  PMB.DisableGVNLoadPRE = DisableGVNLoadPRE;
-  PMB.LoopVectorize = !DisableVectorization;
-  PMB.SLPVectorize = !DisableVectorization;
-  if (!DisableInline)
-    PMB.Inliner = createFunctionInliningPass();
-  PMB.LibraryInfo = new TargetLibraryInfoImpl(TargetTriple);
-  if (Freestanding)
-    PMB.LibraryInfo->disableAllFunctions();
-  PMB.OptLevel = OptLevel;
-  PMB.VerifyInput = !DisableVerify;
-  PMB.VerifyOutput = !DisableVerify;
+  // TODO: Disable inlining
+  //  if (!DisableInline)
+  // PMB.Inliner = createFunctionInliningPass();
 
-  PMB.populateLTOPassManager(passes);
+  lto::Config Conf;
+  Conf.StatsFile = LTOStatsFile;
+  Conf.OptLevel = OptLevel;
+  Conf.Freestanding = Freestanding;
+  Conf.PTO.LoopVectorization = OptLevel > 1 && !DisableVectorization;
+  Conf.PTO.SLPVectorization = OptLevel > 1 && !DisableVectorization;
+  Conf.DisableVerify = DisableVerify;
 
-  // Run our queue of passes all at once now, efficiently.
-  passes.run(*MergedModule);
+  ModuleSummaryIndex CombinedIndex(false);
+  TargetMach = createTargetMachine();
+  if (!opt(Conf, TargetMach.get(), 0, *MergedModule, /*IsThinLTO=*/false,
+           /*ExportSummary=*/&CombinedIndex, /*ImportSummary=*/nullptr,
+           /*CmdArgs*/ std::vector<uint8_t>())) {
+    return false;
+  }
+
+  if (StatsFile) {
+    PrintStatisticsJSON(StatsFile->os());
+  }
 
+  // TODO: report error
   return true;
 }
 
diff --git a/llvm/test/LTO/X86/disable-verify.ll b/llvm/test/LTO/X86/disable-verify.ll
--- a/llvm/test/LTO/X86/disable-verify.ll
+++ b/llvm/test/LTO/X86/disable-verify.ll
@@ -7,7 +7,7 @@
 
 ; -disable-verify should disable verification from the optimization pipeline.
 ; CHECK: Pass Arguments:
-; CHECK-NOT: -verify
+; CHECK-NOT: -verify {{.*}} -verify
 
 ; VERIFY: Pass Arguments: {{.*}} -verify {{.*}} -verify
 
diff --git a/llvm/test/tools/lto/print-stats.ll b/llvm/test/tools/lto/print-stats.ll
--- a/llvm/test/tools/lto/print-stats.ll
+++ b/llvm/test/tools/lto/print-stats.ll
@@ -5,5 +5,12 @@
 
 target triple = "x86_64-apple-macosx10.8.0"
 
+define i32 @test(i32 %a) {
+  %r = add i32 %a, 1
+  %r.1 = add i32 1, %a
+  %r.2 = add i32 %r, %r.1
+  ret i32 %r.2
+}
+
 ; STATS: Statistics Collected
 ; NO_STATS-NOT: Statistics Collected