1 files changed, 42 insertions, 13 deletions

diff --git a/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp b/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
index 670097010085..fc1e70b1b3d3 100644
--- a/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
+++ b/llvm/lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
@@ -18,9 +18,7 @@
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/Module.h"
 #include "llvm/IR/PassManager.h"
-#include "llvm/InitializePasses.h"
 #include "llvm/Object/ModuleSymbolTable.h"
-#include "llvm/Pass.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/IPO.h"
 #include "llvm/Transforms/IPO/FunctionAttrs.h"
@@ -148,6 +146,14 @@ void promoteTypeIds(Module &M, StringRef ModuleId) {
     }
   }
 
+  if (Function *TypeCheckedLoadRelativeFunc = M.getFunction(
+          Intrinsic::getName(Intrinsic::type_checked_load_relative))) {
+    for (const Use &U : TypeCheckedLoadRelativeFunc->uses()) {
+      auto CI = cast<CallInst>(U.getUser());
+      ExternalizeTypeId(CI, 2);
+    }
+  }
+
   for (GlobalObject &GO : M.global_objects()) {
     SmallVector<MDNode *, 1> MDs;
     GO.getMetadata(LLVMContext::MD_type, MDs);
@@ -196,6 +202,13 @@ void simplifyExternals(Module &M) {
     F.eraseFromParent();
   }
 
+  for (GlobalIFunc &I : llvm::make_early_inc_range(M.ifuncs())) {
+    if (I.use_empty())
+      I.eraseFromParent();
+    else
+      assert(I.getResolverFunction() && "ifunc misses its resolver function");
+  }
+
   for (GlobalVariable &GV : llvm::make_early_inc_range(M.globals())) {
     if (GV.isDeclaration() && GV.use_empty()) {
       GV.eraseFromParent();
@@ -246,6 +259,16 @@ static void cloneUsedGlobalVariables(const Module &SrcM, Module &DestM,
     appendToUsed(DestM, NewUsed);
 }
 
+#ifndef NDEBUG
+static bool enableUnifiedLTO(Module &M) {
+  bool UnifiedLTO = false;
+  if (auto *MD =
+          mdconst::extract_or_null<ConstantInt>(M.getModuleFlag("UnifiedLTO")))
+    UnifiedLTO = MD->getZExtValue();
+  return UnifiedLTO;
+}
+#endif
+
 // If it's possible to split M into regular and thin LTO parts, do so and write
 // a multi-module bitcode file with the two parts to OS. Otherwise, write only a
 // regular LTO bitcode file to OS.
@@ -254,18 +277,20 @@ void splitAndWriteThinLTOBitcode(
     function_ref<AAResults &(Function &)> AARGetter, Module &M) {
   std::string ModuleId = getUniqueModuleId(&M);
   if (ModuleId.empty()) {
+    assert(!enableUnifiedLTO(M));
     // We couldn't generate a module ID for this module, write it out as a
     // regular LTO module with an index for summary-based dead stripping.
     ProfileSummaryInfo PSI(M);
     M.addModuleFlag(Module::Error, "ThinLTO", uint32_t(0));
     ModuleSummaryIndex Index = buildModuleSummaryIndex(M, nullptr, &PSI);
-    WriteBitcodeToFile(M, OS, /*ShouldPreserveUseListOrder=*/false, &Index);
+    WriteBitcodeToFile(M, OS, /*ShouldPreserveUseListOrder=*/false, &Index,
+                       /*UnifiedLTO=*/false);
 
     if (ThinLinkOS)
       // We don't have a ThinLTO part, but still write the module to the
       // ThinLinkOS if requested so that the expected output file is produced.
       WriteBitcodeToFile(M, *ThinLinkOS, /*ShouldPreserveUseListOrder=*/false,
-                         &Index);
+                         &Index, /*UnifiedLTO=*/false);
 
     return;
   }
@@ -503,15 +528,17 @@ bool hasTypeMetadata(Module &M) {
   return false;
 }
 
-void writeThinLTOBitcode(raw_ostream &OS, raw_ostream *ThinLinkOS,
+bool writeThinLTOBitcode(raw_ostream &OS, raw_ostream *ThinLinkOS,
                          function_ref<AAResults &(Function &)> AARGetter,
                          Module &M, const ModuleSummaryIndex *Index) {
   std::unique_ptr<ModuleSummaryIndex> NewIndex = nullptr;
   // See if this module has any type metadata. If so, we try to split it
   // or at least promote type ids to enable WPD.
   if (hasTypeMetadata(M)) {
-    if (enableSplitLTOUnit(M))
-      return splitAndWriteThinLTOBitcode(OS, ThinLinkOS, AARGetter, M);
+    if (enableSplitLTOUnit(M)) {
+      splitAndWriteThinLTOBitcode(OS, ThinLinkOS, AARGetter, M);
+      return true;
+    }
     // Promote type ids as needed for index-based WPD.
     std::string ModuleId = getUniqueModuleId(&M);
     if (!ModuleId.empty()) {
@@ -544,6 +571,7 @@ void writeThinLTOBitcode(raw_ostream &OS, raw_ostream *ThinLinkOS,
   // given OS.
   if (ThinLinkOS && Index)
     writeThinLinkBitcodeToFile(M, *ThinLinkOS, *Index, ModHash);
+  return false;
 }
 
 } // anonymous namespace
@@ -552,10 +580,11 @@ PreservedAnalyses
 llvm::ThinLTOBitcodeWriterPass::run(Module &M, ModuleAnalysisManager &AM) {
   FunctionAnalysisManager &FAM =
       AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
-  writeThinLTOBitcode(OS, ThinLinkOS,
-                      [&FAM](Function &F) -> AAResults & {
-                        return FAM.getResult<AAManager>(F);
-                      },
-                      M, &AM.getResult<ModuleSummaryIndexAnalysis>(M));
-  return PreservedAnalyses::all();
+  bool Changed = writeThinLTOBitcode(
+      OS, ThinLinkOS,
+      [&FAM](Function &F) -> AAResults & {
+        return FAM.getResult<AAManager>(F);
+      },
+      M, &AM.getResult<ModuleSummaryIndexAnalysis>(M));
+  return Changed ? PreservedAnalyses::none() : PreservedAnalyses::all();
 }