diff --git a/clang/lib/CodeGen/BackendUtil.cpp b/clang/lib/CodeGen/BackendUtil.cpp
index f01a6514f6eff..8c666e2cb463c 100644
--- a/clang/lib/CodeGen/BackendUtil.cpp
+++ b/clang/lib/CodeGen/BackendUtil.cpp
@@ -996,9 +996,8 @@ void EmitAssemblyHelper::RunOptimizationPipeline(
     }
 
     if (CodeGenOpts.FatLTO) {
-      MPM.addPass(PB.buildFatLTODefaultPipeline(
-          Level, PrepareForThinLTO,
-          PrepareForThinLTO || shouldEmitRegularLTOSummary()));
+      assert(CodeGenOpts.UnifiedLTO && "FatLTO requires UnifiedLTO");
+      MPM.addPass(PB.buildFatLTODefaultPipeline(Level));
     } else if (PrepareForThinLTO) {
       MPM.addPass(PB.buildThinLTOPreLinkDefaultPipeline(Level));
     } else if (PrepareForLTO) {
@@ -1042,7 +1041,6 @@ void EmitAssemblyHelper::RunOptimizationPipeline(
         MPM.addPass(PrintModulePass(*OS, "", CodeGenOpts.EmitLLVMUseLists,
                                     /*EmitLTOSummary=*/true));
       }
-
     } else {
       // Emit a module summary by default for Regular LTO except for ld64
       // targets
@@ -1073,7 +1071,8 @@ void EmitAssemblyHelper::RunOptimizationPipeline(
     if (!TheModule->getModuleFlag("EnableSplitLTOUnit"))
       TheModule->addModuleFlag(llvm::Module::Error, "EnableSplitLTOUnit",
                                uint32_t(CodeGenOpts.EnableSplitLTOUnit));
-    if (CodeGenOpts.UnifiedLTO && !TheModule->getModuleFlag("UnifiedLTO"))
+    // FatLTO always means UnifiedLTO
+    if (!TheModule->getModuleFlag("UnifiedLTO"))
       TheModule->addModuleFlag(llvm::Module::Error, "UnifiedLTO", uint32_t(1));
   }
 
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 3c8df8a9037d6..b1ce95be38f88 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -4862,7 +4862,9 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   bool UnifiedLTO = false;
   if (IsUsingLTO) {
     UnifiedLTO = Args.hasFlag(options::OPT_funified_lto,
-                              options::OPT_fno_unified_lto, Triple.isPS());
+                              options::OPT_fno_unified_lto, Triple.isPS()) ||
+                 Args.hasFlag(options::OPT_ffat_lto_objects,
+                              options::OPT_fno_fat_lto_objects, false);
     if (UnifiedLTO)
       CmdArgs.push_back("-funified-lto");
   }
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 5a8e4cf9843de..a6188cb45e178 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -1861,6 +1861,20 @@ bool CompilerInvocation::ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args,
     if (Args.hasArg(OPT_funified_lto))
       Opts.PrepareForThinLTO = true;
   }
+  if (Arg *A = Args.getLastArg(options::OPT_ffat_lto_objects,
+                               options::OPT_fno_fat_lto_objects)) {
+    if (A->getOption().matches(options::OPT_ffat_lto_objects)) {
+      if (Arg *Uni = Args.getLastArg(options::OPT_funified_lto,
+                                     options::OPT_fno_unified_lto)) {
+        if (Uni->getOption().matches(options::OPT_fno_unified_lto))
+          Diags.Report(diag::err_drv_incompatible_options)
+              << A->getAsString(Args) << "-fno-unified-lto";
+      } else
+        Diags.Report(diag::err_drv_argument_only_allowed_with)
+            << A->getAsString(Args) << "-funified-lto";
+    }
+  }
+
   if (Arg *A = Args.getLastArg(OPT_fthinlto_index_EQ)) {
     if (IK.getLanguage() != Language::LLVM_IR)
       Diags.Report(diag::err_drv_argument_only_allowed_with)
diff --git a/clang/test/CodeGen/fat-lto-objects.c b/clang/test/CodeGen/fat-lto-objects.c
index 2c3a4ef9c6155..95207e77c244c 100644
--- a/clang/test/CodeGen/fat-lto-objects.c
+++ b/clang/test/CodeGen/fat-lto-objects.c
@@ -1,49 +1,47 @@
 // REQUIRES: x86-registered-target
 
-// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=full -ffat-lto-objects -fsplit-lto-unit -emit-llvm < %s  | FileCheck %s --check-prefixes=FULL,SPLIT
-// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=full -ffat-lto-objects -emit-llvm < %s  | FileCheck %s --check-prefixes=FULL,SPLIT
+// RUN: not %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=full -ffat-lto-objects -fsplit-lto-unit -emit-llvm < %s 2>&1 | FileCheck %s --check-prefixes=NO-UNIFIED
 
-// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=thin -fsplit-lto-unit -ffat-lto-objects -emit-llvm < %s  | FileCheck %s --check-prefixes=THIN,SPLIT
-// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=thin -ffat-lto-objects -emit-llvm < %s  | FileCheck %s --check-prefixes=THIN,NOSPLIT
+// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=full -funified-lto -ffat-lto-objects -fsplit-lto-unit -emit-llvm < %s  | FileCheck %s --check-prefixes=FULL,SPLIT,UNIFIED
+// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=full -funified-lto -ffat-lto-objects -emit-llvm < %s  | FileCheck %s --check-prefixes=FULL,NOSPLIT,UNIFIED
 
-// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=full -ffat-lto-objects -fsplit-lto-unit -emit-obj < %s -o %t.full.split.o
+// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=thin -funified-lto -fsplit-lto-unit -ffat-lto-objects -emit-llvm < %s  | FileCheck %s --check-prefixes=THIN,SPLIT,UNIFIED
+// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=thin -funified-lto -ffat-lto-objects -emit-llvm < %s  | FileCheck %s --check-prefixes=THIN,NOSPLIT,UNIFIED
+
+// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=full -funified-lto -ffat-lto-objects -fsplit-lto-unit -emit-obj < %s -o %t.full.split.o
 // RUN: llvm-readelf -S %t.full.split.o | FileCheck %s --check-prefixes=ELF
 // RUN: llvm-objcopy --dump-section=.llvm.lto=%t.full.split.bc %t.full.split.o
-// RUN: llvm-dis %t.full.split.bc -o - | FileCheck %s --check-prefixes=FULL,SPLIT,NOUNIFIED
+// RUN: llvm-dis %t.full.split.bc -o - | FileCheck %s --check-prefixes=THIN,SPLIT,UNIFIED
 
-// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=full -ffat-lto-objects -emit-obj < %s -o %t.full.nosplit.o
+// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=full -funified-lto -ffat-lto-objects -emit-obj < %s -o %t.full.nosplit.o
 // RUN: llvm-readelf -S %t.full.nosplit.o | FileCheck %s --check-prefixes=ELF
 // RUN: llvm-objcopy --dump-section=.llvm.lto=%t.full.nosplit.bc %t.full.nosplit.o
-// RUN: llvm-dis %t.full.nosplit.bc -o - | FileCheck %s --check-prefixes=FULL,NOSPLIT,NOUNIFIED
+// RUN: llvm-dis %t.full.nosplit.bc -o - | FileCheck %s --check-prefixes=THIN,NOSPLIT,UNIFIED
 
-// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=thin -fsplit-lto-unit -ffat-lto-objects -emit-obj < %s -o %t.thin.split.o
+// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=thin -funified-lto -fsplit-lto-unit -ffat-lto-objects -emit-obj < %s -o %t.thin.split.o
 // RUN: llvm-readelf -S %t.thin.split.o | FileCheck %s --check-prefixes=ELF
 // RUN: llvm-objcopy --dump-section=.llvm.lto=%t.thin.split.bc %t.thin.split.o
-// RUN: llvm-dis %t.thin.split.bc -o - | FileCheck %s --check-prefixes=THIN,SPLIT,NOUNIFIED
+// RUN: llvm-dis %t.thin.split.bc -o - | FileCheck %s --check-prefixes=THIN,SPLIT,UNIFIED
 
-// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=thin -ffat-lto-objects -emit-obj < %s -o %t.thin.nosplit.o
+// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=thin -funified-lto -ffat-lto-objects -emit-obj < %s -o %t.thin.nosplit.o
 // RUN: llvm-readelf -S %t.thin.nosplit.o | FileCheck %s --check-prefixes=ELF
 // RUN: llvm-objcopy --dump-section=.llvm.lto=%t.thin.nosplit.bc %t.thin.nosplit.o
-// RUN: llvm-dis %t.thin.nosplit.bc -o -  | FileCheck %s --check-prefixes=THIN,NOSPLIT,NOUNIFIED
-
-// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=thin -funified-lto -ffat-lto-objects -emit-obj < %s -o %t.unified.o
-// RUN: llvm-readelf -S %t.unified.o | FileCheck %s --check-prefixes=ELF
-// RUN: llvm-objcopy --dump-section=.llvm.lto=%t.unified.bc %t.unified.o
-// RUN: llvm-dis %t.unified.bc -o - | FileCheck %s --check-prefixes=THIN,NOSPLIT,UNIFIED
+// RUN: llvm-dis %t.thin.nosplit.bc -o -  | FileCheck %s --check-prefixes=THIN,NOSPLIT,UNIFIED
 
-// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=full -ffat-lto-objects -fsplit-lto-unit -S < %s -o - \
+// RUN: %clang -cc1 -triple x86_64-unknown-linux-gnu -flto=full -funified-lto -ffat-lto-objects -fsplit-lto-unit -S < %s -o - \
 // RUN: | FileCheck %s --check-prefixes=ASM
 
-/// Check that the ThinLTO metadata is only set false for full LTO.
-// FULL: ![[#]] = !{i32 1, !"ThinLTO", i32 0}
-// THIN-NOT: ![[#]] = !{i32 1, !"ThinLTO", i32 0}
-
 /// Be sure we enable split LTO units correctly under -ffat-lto-objects.
-// SPLIT: ![[#]] = !{i32 1, !"EnableSplitLTOUnit", i32 1}
+//   SPLIT: ![[#]] = !{i32 1, !"EnableSplitLTOUnit", i32 1}
 // NOSPLIT: ![[#]] = !{i32 1, !"EnableSplitLTOUnit", i32 0}
 
-// UNIFIED: ![[#]] = !{i32 1, !"UnifiedLTO", i32 1}
-// NOUNIFIED-NOT: ![[#]] = !{i32 1, !"UnifiedLTO", i32 1}
+/// Check that the ThinLTO metadata is set true for both full and thin LTO, since FatLTO is based on UnifiedLTO.
+//     FULL: ![[#]] = !{i32 1, !"ThinLTO", i32 1}
+// THIN-NOT: ![[#]] = !{i32 1, !"ThinLTO", i32 0}
+
+/// FatLTO always uses UnifiedLTO. It's an error if they aren't set together
+//    UNIFIED: ![[#]] = !{i32 1, !"UnifiedLTO", i32 1}
+// NO-UNIFIED: error: invalid argument '-ffat-lto-objects' only allowed with '-funified-lto'
 
 // ELF: .llvm.lto
 
diff --git a/clang/test/Driver/fat-lto-objects.c b/clang/test/Driver/fat-lto-objects.c
index 887c33fa76d71..e02359db3f0ae 100644
--- a/clang/test/Driver/fat-lto-objects.c
+++ b/clang/test/Driver/fat-lto-objects.c
@@ -1,5 +1,6 @@
 // RUN: %clang --target=x86_64-unknown-linux-gnu -flto -ffat-lto-objects -### %s -c 2>&1 | FileCheck %s -check-prefix=CHECK-CC
 // CHECK-CC: -cc1
+// CHECK-CC-SAME: -funified-lto
 // CHECK-CC-SAME: -emit-obj
 // CHECK-CC-SAME: -ffat-lto-objects
 
@@ -15,6 +16,7 @@
 // RUN: %clang --target=x86_64-unknown-linux-gnu -flto -ffat-lto-objects -### %s -S 2>&1 | FileCheck %s -check-prefix=CHECK-CC-S-LTO
 // RUN: %clang --target=x86_64-unknown-linux-gnu -flto -ffat-lto-objects -### %s -S -emit-llvm 2>&1 | FileCheck %s -check-prefix=CHECK-CC-S-LTO
 // CHECK-CC-S-LTO: -cc1
+// CHECK-CC-S-LTO-SAME: -funified-lto
 // CHECK-CC-S-LTO-SAME: -emit-llvm
 // CHECK-CC-S-LTO-SAME: -ffat-lto-objects
 
@@ -32,3 +34,13 @@
 // RUN:   -fuse-ld=lld -fno-lto -ffat-lto-objects -### 2>&1 | FileCheck --check-prefix=NOLTO %s
 // LTO: "--fat-lto-objects"
 // NOLTO-NOT: "--fat-lto-objects"
+
+/// Make sure that incompatible options emit the correct diagnostics, since -ffat-lto-objects requires -funified-lto
+// RUN: %clang -cc1 -triple=x86_64-unknown-linux-gnu -flto -ffat-lto-objects -funified-lto -emit-llvm-only %s  2>&1 | FileCheck %s -check-prefix=UNIFIED --allow-empty
+// UNIFIED-NOT: error:
+
+// RUN: not %clang -cc1 -triple=x86_64-unknown-linux-gnu -flto -ffat-lto-objects -emit-llvm-only %s  2>&1 | FileCheck %s -check-prefix=MISSING_UNIFIED
+// MISSING_UNIFIED: error: invalid argument '-ffat-lto-objects' only allowed with '-funified-lto'
+
+// RUN: not %clang -cc1 -triple=x86_64-unknown-linux-gnu -flto -fno-unified-lto -ffat-lto-objects -emit-llvm-only %s  2>&1 | FileCheck %s -check-prefix=NO-UNIFIED
+// NO-UNIFIED: error: the combination of '-ffat-lto-objects' and '-fno-unified-lto' is incompatible
diff --git a/llvm/docs/FatLTO.rst b/llvm/docs/FatLTO.rst
index b505bb2a96fe1..21da24504bcdf 100644
--- a/llvm/docs/FatLTO.rst
+++ b/llvm/docs/FatLTO.rst
@@ -29,30 +29,31 @@ Overview
 Within LLVM, FatLTO is supported by choosing the ``FatLTODefaultPipeline``.
 This pipeline will:
 
-#) Clone the IR module.
-#) Run the pre-link (Thin)LTO pipeline using the cloned module.
+#) Run the pre-link UnifiedLTO pipeline on the current module.
 #) Embed the pre-link bitcode in a special ``.llvm.lto`` section.
-#) Optimize the unmodified copy of the module using the normal compilation pipeline.
+#) Finish optimizing the module using the post-link ThinLTO pipeline.
 #) Emit the object file, including the new ``.llvm.lto`` section.
 
 .. NOTE
 
-   At the time of writing, we conservatively run independent pipelines to
-   generate the bitcode section and the object code, which happen to be
-   identical to those used outside of FatLTO. This results in  compiled
-   artifacts that are identical to those produced by the default and (Thin)LTO
-   pipelines. However, this is not a guarantee, and we reserve the right to
-   change this at any time. Explicitly, users should not rely on the produced
-   bitcode or object code to mach their non-LTO counterparts precisely. They
-   will exhibit similar performance characteristics, but may not be bit-for-bit
-   the same.
+   Previously, we conservatively ran independent pipelines on separate copies
+   of the LLVM module to generate the bitcode section and the object code,
+   which happen to be identical to those used outside of FatLTO. While that
+   resulted in  compiled artifacts that were identical to those produced by the
+   default and (Thin)LTO pipelines, module cloning led to some cases of
+   miscompilation, and we have moved away from trying to keep bitcode
+   generation and optimization completely disjoint.
+
+   Bit-for-bit compatibility is not (and never was) a guarantee, and we reserve
+   the right to change this at any time. Explicitly, users should not rely on
+   the produced bitcode or object code to match their non-LTO counterparts
+   precisely. They will exhibit similar performance characteristics, but may
+   not be bit-for-bit the same.
 
 Internally, the ``.llvm.lto`` section is created by running the
-``EmbedBitcodePass`` at the start of the ``PerModuleDefaultPipeline``. This
-pass is responsible for cloning and optimizing the module with the appropriate
-LTO pipeline and emitting the ``.llvm.lto`` section. Afterwards, the
-``PerModuleDefaultPipeline`` runs normally and the compiler can emit the fat
-object file.
+``EmbedBitcodePass`` after the ``ThinLTOPreLinkDefaultPipeline``. This pass is
+responsible for emitting the ``.llvm.lto`` section. Afterwards, the
+``ThinLTODefaultPipeline`` runs and the compiler can emit the fat object file.
 
 Limitations
 ===========
diff --git a/llvm/include/llvm/Passes/PassBuilder.h b/llvm/include/llvm/Passes/PassBuilder.h
index 23bc891a8f1e9..19ac90842bcb0 100644
--- a/llvm/include/llvm/Passes/PassBuilder.h
+++ b/llvm/include/llvm/Passes/PassBuilder.h
@@ -246,8 +246,7 @@ class PassBuilder {
   /// separately to avoid any inconsistencies with an ad-hoc pipeline that tries
   /// to approximate the PerModuleDefaultPipeline from the pre-link LTO
   /// pipelines.
-  ModulePassManager buildFatLTODefaultPipeline(OptimizationLevel Level,
-                                               bool ThinLTO, bool EmitSummary);
+  ModulePassManager buildFatLTODefaultPipeline(OptimizationLevel Level);
 
   /// Build a pre-link, ThinLTO-targeting default optimization pipeline to
   /// a pass manager.
diff --git a/llvm/include/llvm/Transforms/IPO/EmbedBitcodePass.h b/llvm/include/llvm/Transforms/IPO/EmbedBitcodePass.h
index f323c61483fd3..c35048c91aba2 100644
--- a/llvm/include/llvm/Transforms/IPO/EmbedBitcodePass.h
+++ b/llvm/include/llvm/Transforms/IPO/EmbedBitcodePass.h
@@ -25,28 +25,13 @@ class Module;
 class ModulePass;
 class Pass;
 
-struct EmbedBitcodeOptions {
-  EmbedBitcodeOptions() : EmbedBitcodeOptions(false, false) {}
-  EmbedBitcodeOptions(bool IsThinLTO, bool EmitLTOSummary)
-      : IsThinLTO(IsThinLTO), EmitLTOSummary(EmitLTOSummary) {}
-  bool IsThinLTO;
-  bool EmitLTOSummary;
-};
-
 /// Pass embeds a copy of the module optimized with the provided pass pipeline
 /// into a global variable.
 class EmbedBitcodePass : public PassInfoMixin<EmbedBitcodePass> {
-  bool IsThinLTO;
-  bool EmitLTOSummary;
   ModulePassManager MPM;
 
 public:
-  EmbedBitcodePass(EmbedBitcodeOptions Opts)
-      : EmbedBitcodePass(Opts.IsThinLTO, Opts.EmitLTOSummary,
-                         ModulePassManager()) {}
-  EmbedBitcodePass(bool IsThinLTO, bool EmitLTOSummary, ModulePassManager &&MPM)
-      : IsThinLTO(IsThinLTO), EmitLTOSummary(EmitLTOSummary),
-        MPM(std::move(MPM)) {}
+  EmbedBitcodePass() {}
 
   PreservedAnalyses run(Module &M, ModuleAnalysisManager &);
 
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index aeb9726a186b5..98a679177c23d 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -759,26 +759,6 @@ Expected<HWAddressSanitizerOptions> parseHWASanPassOptions(StringRef Params) {
   return Result;
 }
 
-Expected<EmbedBitcodeOptions> parseEmbedBitcodePassOptions(StringRef Params) {
-  EmbedBitcodeOptions Result;
-  while (!Params.empty()) {
-    StringRef ParamName;
-    std::tie(ParamName, Params) = Params.split(';');
-
-    if (ParamName == "thinlto") {
-      Result.IsThinLTO = true;
-    } else if (ParamName == "emit-summary") {
-      Result.EmitLTOSummary = true;
-    } else {
-      return make_error<StringError>(
-          formatv("invalid EmbedBitcode pass parameter '{0}' ", ParamName)
-              .str(),
-          inconvertibleErrorCode());
-    }
-  }
-  return Result;
-}
-
 Expected<MemorySanitizerOptions> parseMSanPassOptions(StringRef Params) {
   MemorySanitizerOptions Result;
   while (!Params.empty()) {
diff --git a/llvm/lib/Passes/PassBuilderPipelines.cpp b/llvm/lib/Passes/PassBuilderPipelines.cpp
index f3d280316e040..e7f88680655c1 100644
--- a/llvm/lib/Passes/PassBuilderPipelines.cpp
+++ b/llvm/lib/Passes/PassBuilderPipelines.cpp
@@ -1530,14 +1530,22 @@ PassBuilder::buildPerModuleDefaultPipeline(OptimizationLevel Level,
 }
 
 ModulePassManager
-PassBuilder::buildFatLTODefaultPipeline(OptimizationLevel Level, bool ThinLTO,
-                                        bool EmitSummary) {
+PassBuilder::buildFatLTODefaultPipeline(OptimizationLevel Level) {
   ModulePassManager MPM;
-  MPM.addPass(EmbedBitcodePass(ThinLTO, EmitSummary,
-                               ThinLTO
-                                   ? buildThinLTOPreLinkDefaultPipeline(Level)
-                                   : buildLTOPreLinkDefaultPipeline(Level)));
-  MPM.addPass(buildPerModuleDefaultPipeline(Level));
+  // FatLTO always uses UnifiedLTO, so use the ThinLTOPreLink pipeline
+  MPM.addPass(buildThinLTOPreLinkDefaultPipeline(Level));
+  MPM.addPass(EmbedBitcodePass());
+
+  // Use the ThinLTO post-link pipeline with sample profiling, other
+  if (PGOOpt && PGOOpt->Action == PGOOptions::SampleUse)
+    MPM.addPass(buildThinLTODefaultPipeline(Level, /*ImportSummary=*/nullptr));
+  else {
+    // otherwise, just use module optimization
+    MPM.addPass(
+        buildModuleOptimizationPipeline(Level, ThinOrFullLTOPhase::None));
+    // Emit annotation remarks.
+    addAnnotationRemarksPass(MPM);
+  }
   return MPM;
 }
 
diff --git a/llvm/lib/Passes/PassRegistry.def b/llvm/lib/Passes/PassRegistry.def
index 1f1bc3222468b..2abc2920264a6 100644
--- a/llvm/lib/Passes/PassRegistry.def
+++ b/llvm/lib/Passes/PassRegistry.def
@@ -58,6 +58,7 @@ MODULE_PASS("dfsan", DataFlowSanitizerPass())
 MODULE_PASS("dot-callgraph", CallGraphDOTPrinterPass())
 MODULE_PASS("dxil-upgrade", DXILUpgradePass())
 MODULE_PASS("elim-avail-extern", EliminateAvailableExternallyPass())
+MODULE_PASS("embed-bitcode", EmbedBitcodePass())
 MODULE_PASS("extract-blocks", BlockExtractorPass({}, false))
 MODULE_PASS("forceattrs", ForceFunctionAttrsPass())
 MODULE_PASS("function-import", FunctionImportPass())
@@ -145,10 +146,6 @@ MODULE_PASS_WITH_PARAMS(
     "asan", "AddressSanitizerPass",
     [](AddressSanitizerOptions Opts) { return AddressSanitizerPass(Opts); },
     parseASanPassOptions, "kernel")
-MODULE_PASS_WITH_PARAMS(
-    "embed-bitcode", "EmbedBitcodePass",
-    [](EmbedBitcodeOptions Opts) { return EmbedBitcodePass(Opts); },
-    parseEmbedBitcodePassOptions, "thinlto;emit-summary")
 MODULE_PASS_WITH_PARAMS(
     "globaldce", "GlobalDCEPass",
     [](bool InLTOPostLink) { return GlobalDCEPass(InLTOPostLink); },
diff --git a/llvm/lib/Transforms/IPO/EmbedBitcodePass.cpp b/llvm/lib/Transforms/IPO/EmbedBitcodePass.cpp
index fa56a5b564ae6..48ef0772e800e 100644
--- a/llvm/lib/Transforms/IPO/EmbedBitcodePass.cpp
+++ b/llvm/lib/Transforms/IPO/EmbedBitcodePass.cpp
@@ -7,8 +7,6 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/IPO/EmbedBitcodePass.h"
-#include "llvm/Bitcode/BitcodeWriter.h"
-#include "llvm/Bitcode/BitcodeWriterPass.h"
 #include "llvm/IR/PassManager.h"
 #include "llvm/Pass.h"
 #include "llvm/Support/ErrorHandling.h"
@@ -16,10 +14,8 @@
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/TargetParser/Triple.h"
 #include "llvm/Transforms/IPO/ThinLTOBitcodeWriter.h"
-#include "llvm/Transforms/Utils/Cloning.h"
 #include "llvm/Transforms/Utils/ModuleUtils.h"
 
-#include <memory>
 #include <string>
 
 using namespace llvm;
@@ -34,19 +30,9 @@ PreservedAnalyses EmbedBitcodePass::run(Module &M, ModuleAnalysisManager &AM) {
     report_fatal_error(
         "EmbedBitcode pass currently only supports ELF object format",
         /*gen_crash_diag=*/false);
-
-  std::unique_ptr<Module> NewModule = CloneModule(M);
-  MPM.run(*NewModule, AM);
-
   std::string Data;
   raw_string_ostream OS(Data);
-  if (IsThinLTO)
-    ThinLTOBitcodeWriterPass(OS, /*ThinLinkOS=*/nullptr).run(*NewModule, AM);
-  else
-    BitcodeWriterPass(OS, /*ShouldPreserveUseListOrder=*/false, EmitLTOSummary)
-        .run(*NewModule, AM);
-
+  ThinLTOBitcodeWriterPass(OS, /*ThinLinkOS=*/nullptr).run(M, AM);
   embedBufferInModule(M, MemoryBufferRef(Data, "ModuleData"), ".llvm.lto");
-
   return PreservedAnalyses::all();
 }
diff --git a/llvm/test/CodeGen/X86/fat-lto-section.ll b/llvm/test/CodeGen/X86/fat-lto-section.ll
index 30c56229a0e2a..9a4359bab6b5d 100644
--- a/llvm/test/CodeGen/X86/fat-lto-section.ll
+++ b/llvm/test/CodeGen/X86/fat-lto-section.ll
@@ -1,5 +1,5 @@
 ;; Ensure that the .llvm.lto section has SHT_EXCLUDE set.
-; RUN: opt --mtriple x86_64-unknown-linux-gnu < %s -passes="embed-bitcode<thinlto;emit-summary>" -S \
+; RUN: opt --mtriple x86_64-unknown-linux-gnu < %s -passes="embed-bitcode" -S \
 ; RUN:   | llc --mtriple x86_64-unknown-linux-gnu -filetype=obj \
 ; RUN:   | llvm-readelf - --sections \
 ; RUN:   | FileCheck %s --check-prefix=EXCLUDE
diff --git a/llvm/test/Transforms/EmbedBitcode/embed.ll b/llvm/test/Transforms/EmbedBitcode/embed.ll
index dffb5cf755477..734bf5274a5f2 100644
--- a/llvm/test/Transforms/EmbedBitcode/embed.ll
+++ b/llvm/test/Transforms/EmbedBitcode/embed.ll
@@ -1,7 +1,4 @@
 ; RUN: opt --mtriple x86_64-unknown-linux-gnu < %s -passes="embed-bitcode" -S | FileCheck %s
-; RUN: opt --mtriple x86_64-unknown-linux-gnu < %s -passes="embed-bitcode<thinlto>" -S | FileCheck %s
-; RUN: opt --mtriple x86_64-unknown-linux-gnu < %s -passes="embed-bitcode<emit-summary>" -S | FileCheck %s
-; RUN: opt --mtriple x86_64-unknown-linux-gnu < %s -passes="embed-bitcode<thinlto;emit-summary>" -S | FileCheck %s
 
 @a = global i32 1