Revert "Make aliases explicit in the summary"

Inadvertently commited...

This reverts commit e618ec93786d99df2ddf280ad2d5e02f5516cecf.

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266215

2 files changed, 3 insertions, 118 deletions

diff --git a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
index e5fb51b1bed..321c775531e 100644
--- a/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/llvm/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -5848,35 +5848,6 @@ std::error_code ModuleSummaryIndexBitcodeReader::parseEntireSummary() {
       Info->setSummary(std::move(FS));
       break;
     }
-    // FS_ALIAS: [valueid, linkage, valueid]
-    // Aliases must be emitted (and parsed) after all FS_PERMODULE entries, as
-    // they expect all aliasee summaries to be available.
-    case bitc::FS_ALIAS: {
-      unsigned ValueID = Record[0];
-      uint64_t RawLinkage = Record[1];
-      unsigned AliaseeID = Record[2];
-      std::unique_ptr<AliasSummary> AS =
-          llvm::make_unique<AliasSummary>(getDecodedLinkage(RawLinkage));
-      // The module path string ref set in the summary must be owned by the
-      // index's module string table. Since we don't have a module path
-      // string table section in the per-module index, we create a single
-      // module path string table entry with an empty (0) ID to take
-      // ownership.
-      AS->setModulePath(
-          TheIndex->addModulePath(Buffer->getBufferIdentifier(), 0)->first());
-
-      GlobalValue::GUID AliaseeGUID = getGUIDFromValueId(AliaseeID);
-      auto *AliaseeInfo = TheIndex->getGlobalValueInfo(AliaseeGUID);
-      if (!AliaseeInfo->summary())
-        return error("Alias expects aliasee summary to be parsed");
-      AS->setAliasee(AliaseeInfo->summary());
-
-      GlobalValue::GUID GUID = getGUIDFromValueId(ValueID);
-      auto *Info = TheIndex->getGlobalValueInfo(GUID);
-      assert(!Info->summary() && "Expected a single summary per VST entry");
-      Info->setSummary(std::move(AS));
-      break;
-    }
     // FS_PERMODULE_GLOBALVAR_INIT_REFS: [valueid, linkage, n x valueid]
     case bitc::FS_PERMODULE_GLOBALVAR_INIT_REFS: {
       unsigned ValueID = Record[0];
@@ -5935,28 +5906,6 @@ std::error_code ModuleSummaryIndexBitcodeReader::parseEntireSummary() {
       Combined = true;
       break;
     }
-    // FS_COMBINED_ALIAS: [modid, linkage, offset]
-    // Aliases must be emitted (and parsed) after all FS_PERMODULE entries, as
-    // they expect all aliasee summaries to be available.
-    case bitc::FS_COMBINED_ALIAS: {
-      uint64_t ModuleId = Record[0];
-      uint64_t RawLinkage = Record[1];
-      uint64_t AliaseeSummaryOffset = Record[2];
-      std::unique_ptr<AliasSummary> AS =
-          llvm::make_unique<AliasSummary>(getDecodedLinkage(RawLinkage));
-      AS->setModulePath(ModuleIdMap[ModuleId]);
-
-      auto *AliaseeInfo = getInfoFromSummaryOffset(AliaseeSummaryOffset);
-      if (!AliaseeInfo->summary())
-        return error("Alias expects aliasee summary to be parsed");
-      AS->setAliasee(AliaseeInfo->summary());
-
-      auto *Info = getInfoFromSummaryOffset(CurRecordBit);
-      assert(!Info->summary() && "Expected a single summary per VST entry");
-      Info->setSummary(std::move(AS));
-      Combined = true;
-      break;
-    }
     // FS_COMBINED_GLOBALVAR_INIT_REFS: [modid, linkage, n x valueid]
     case bitc::FS_COMBINED_GLOBALVAR_INIT_REFS: {
       uint64_t ModuleId = Record[0];
diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
index a55f4954b45..1b90c885a9b 100644
--- a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -2924,24 +2924,16 @@ static void WritePerModuleGlobalValueSummary(const Module *M,
   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(Abbv);
 
-  // Abbrev for FS_ALIAS.
-  Abbv = new BitCodeAbbrev();
-  Abbv->Add(BitCodeAbbrevOp(bitc::FS_ALIAS));
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // linkage
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
-  unsigned FSAliasAbbrev = Stream.EmitAbbrev(Abbv);
-
   SmallVector<uint64_t, 64> NameVals;
   // Iterate over the list of functions instead of the Index to
   // ensure the ordering is stable.
   for (const Function &F : *M) {
     if (F.isDeclaration())
       continue;
-    // We shouldn't have any anonymous functions as they are not supported in
-    // ThinLTO and should be renamed.
+    // Skip anonymous functions. We will emit a function summary for
+    // any aliases below.
     if (!F.hasName())
-      report_fatal_error("Unexpected anonymous function when writing summary");
+      continue;
 
     auto *Info = Index.getGlobalValueInfo(F);
     WritePerModuleFunctionSummaryRecord(
@@ -2955,20 +2947,6 @@ static void WritePerModuleGlobalValueSummary(const Module *M,
   for (const GlobalVariable &G : M->globals())
     WriteModuleLevelReferences(G, Index, VE, NameVals, FSModRefsAbbrev, Stream);
 
-  for (const GlobalAlias &A : M->aliases()) {
-    auto *Aliasee = A.getBaseObject();
-    if (!Aliasee->hasName())
-      // Nameless function don't have an entry in the summary, skip it.
-      continue;
-    auto AliasId = VE.getValueID(&A);
-    auto AliaseeId = VE.getValueID(Aliasee);
-    NameVals.push_back(AliasId);
-    NameVals.push_back(getEncodedLinkage(A.getLinkage()));
-    NameVals.push_back(AliaseeId);
-    Stream.EmitRecord(bitc::FS_ALIAS, NameVals, FSAliasAbbrev);
-    NameVals.clear();
-  }
-
   Stream.ExitBlock();
 }
 
@@ -3012,31 +2990,11 @@ static void WriteCombinedGlobalValueSummary(
   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
   unsigned FSModRefsAbbrev = Stream.EmitAbbrev(Abbv);
 
-  // Abbrev for FS_COMBINED_ALIAS.
-  Abbv = new BitCodeAbbrev();
-  Abbv->Add(BitCodeAbbrevOp(bitc::FS_COMBINED_ALIAS));
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // modid
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // linkage
-  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // offset
-  unsigned FSAliasAbbrev = Stream.EmitAbbrev(Abbv);
-
-  // The aliases are emitted as a post-pass, and will point to the summary
-  // offset id of the aliasee. For this purpose we need to be able to get back
-  // from the summary to the offset
-  SmallVector<GlobalValueInfo *, 64> Aliases;
-  DenseMap<const GlobalValueSummary *, uint64_t> SummaryToOffsetMap;
-
   SmallVector<uint64_t, 64> NameVals;
   for (const auto &FII : Index) {
     for (auto &FI : FII.second) {
       GlobalValueSummary *S = FI->summary();
       assert(S);
-      if (isa<AliasSummary>(S)) {
-        // Will process aliases as a post-pass because the reader wants all
-        // global to be loaded first.
-        Aliases.push_back(FI.get());
-        continue;
-      }
 
       if (auto *VS = dyn_cast<GlobalVarSummary>(S)) {
         NameVals.push_back(Index.getModuleId(VS->modulePath()));
@@ -3059,8 +3017,6 @@ static void WriteCombinedGlobalValueSummary(
         // reader will invoke readRecord after the abbrev id read.
         FI->setBitcodeIndex(Stream.GetCurrentBitNo() +
                             Stream.GetAbbrevIDWidth());
-        // Store temporarily the offset in the map for a possible alias.
-        SummaryToOffsetMap[S] = FI->bitcodeIndex();
 
         // Emit the finished record.
         Stream.EmitRecord(bitc::FS_COMBINED_GLOBALVAR_INIT_REFS, NameVals,
@@ -3112,8 +3068,6 @@ static void WriteCombinedGlobalValueSummary(
       // in the VST entry. Add the current code size since the
       // reader will invoke readRecord after the abbrev id read.
       FI->setBitcodeIndex(Stream.GetCurrentBitNo() + Stream.GetAbbrevIDWidth());
-      // Store temporarily the offset in the map for a possible alias.
-      SummaryToOffsetMap[S] = FI->bitcodeIndex();
 
       unsigned FSAbbrev =
           (HasProfileData ? FSCallsProfileAbbrev : FSCallsAbbrev);
@@ -3126,24 +3080,6 @@ static void WriteCombinedGlobalValueSummary(
     }
   }
 
-  for (auto GVI : Aliases) {
-    AliasSummary *AS = cast<AliasSummary>(GVI->summary());
-    NameVals.push_back(Index.getModuleId(AS->modulePath()));
-    NameVals.push_back(getEncodedLinkage(AS->linkage()));
-    auto AliaseeOffset = SummaryToOffsetMap[&AS->getAliasee()];
-    assert(AliaseeOffset);
-    NameVals.push_back(AliaseeOffset);
-
-    // Record the starting offset of this summary entry for use
-    // in the VST entry. Add the current code size since the
-    // reader will invoke readRecord after the abbrev id read.
-    GVI->setBitcodeIndex(Stream.GetCurrentBitNo() + Stream.GetAbbrevIDWidth());
-
-    // Emit the finished record.
-    Stream.EmitRecord(bitc::FS_COMBINED_ALIAS, NameVals, FSAliasAbbrev);
-    NameVals.clear();
-  }
-
   Stream.ExitBlock();
 }