Revert [ThinLTO] Optimize writeonly globals out

This reverts r365040 (git commit 5cacb914758c7f436b47c8362100f10cef14bbc4)

Speculatively reverting, since this appears to have broken check-lld on
Linux. Partial analysis in https://crbug.com/981168.

llvm-svn: 365097

1 files changed, 15 insertions, 42 deletions

diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
index ab645348c53..51fc5b6e1d2 100644
--- a/llvm/lib/AsmParser/LLParser.cpp
+++ b/llvm/lib/AsmParser/LLParser.cpp
@@ -7849,13 +7849,9 @@ static const auto FwdVIRef = (GlobalValueSummaryMapTy::value_type *)-8;
 
 static void resolveFwdRef(ValueInfo *Fwd, ValueInfo &Resolved) {
   bool ReadOnly = Fwd->isReadOnly();
-  bool WriteOnly = Fwd->isWriteOnly();
-  assert(!(ReadOnly && WriteOnly));
   *Fwd = Resolved;
   if (ReadOnly)
     Fwd->setReadOnly();
-  if (WriteOnly)
-    Fwd->setWriteOnly();
 }
 
 /// Stores the given Name/GUID and associated summary into the Index.
@@ -8085,8 +8081,7 @@ bool LLParser::ParseVariableSummary(std::string Name, GlobalValue::GUID GUID,
   GlobalValueSummary::GVFlags GVFlags = GlobalValueSummary::GVFlags(
       /*Linkage=*/GlobalValue::ExternalLinkage, /*NotEligibleToImport=*/false,
       /*Live=*/false, /*IsLocal=*/false, /*CanAutoHide=*/false);
-  GlobalVarSummary::GVarFlags GVarFlags(/*ReadOnly*/ false,
-                                        /* WriteOnly */ false);
+  GlobalVarSummary::GVarFlags GVarFlags(/*ReadOnly*/ false);
   std::vector<ValueInfo> Refs;
   VTableFuncList VTableFuncs;
   if (ParseToken(lltok::colon, "expected ':' here") ||
@@ -8427,11 +8422,10 @@ bool LLParser::ParseOptionalRefs(std::vector<ValueInfo> &Refs) {
     VContexts.push_back(VC);
   } while (EatIfPresent(lltok::comma));
 
-  // Sort value contexts so that ones with writeonly
-  // and readonly ValueInfo  are at the end of VContexts vector.
-  // See FunctionSummary::specialRefCounts()
+  // Sort value contexts so that ones with readonly ValueInfo are at the end
+  // of VContexts vector. This is needed to match immutableRefCount() behavior.
   llvm::sort(VContexts, [](const ValueContext &VC1, const ValueContext &VC2) {
-    return VC1.VI.getAccessSpecifier() < VC2.VI.getAccessSpecifier();
+    return VC1.VI.isReadOnly() < VC2.VI.isReadOnly();
   });
 
   IdToIndexMapType IdToIndexMap;
@@ -8749,41 +8743,24 @@ bool LLParser::ParseGVFlags(GlobalValueSummary::GVFlags &GVFlags) {
 }
 
 /// GVarFlags
-///   ::= 'varFlags' ':' '(' 'readonly' ':' Flag
-///                      ',' 'writeonly' ':' Flag ')'
+///   ::= 'varFlags' ':' '(' 'readonly' ':' Flag ')'
 bool LLParser::ParseGVarFlags(GlobalVarSummary::GVarFlags &GVarFlags) {
   assert(Lex.getKind() == lltok::kw_varFlags);
   Lex.Lex();
 
+  unsigned Flag = 0;
   if (ParseToken(lltok::colon, "expected ':' here") ||
-      ParseToken(lltok::lparen, "expected '(' here"))
+      ParseToken(lltok::lparen, "expected '(' here") ||
+      ParseToken(lltok::kw_readonly, "expected 'readonly' here") ||
+      ParseToken(lltok::colon, "expected ':' here"))
     return true;
 
-  auto ParseRest = [this](unsigned int &Val) {
-    Lex.Lex();
-    if (ParseToken(lltok::colon, "expected ':'"))
-      return true;
-    return ParseFlag(Val);
-  };
+  ParseFlag(Flag);
+  GVarFlags.ReadOnly = Flag;
 
-  do {
-    unsigned Flag = 0;
-    switch (Lex.getKind()) {
-    case lltok::kw_readonly:
-      if (ParseRest(Flag))
-        return true;
-      GVarFlags.MaybeReadOnly = Flag;
-      break;
-    case lltok::kw_writeonly:
-      if (ParseRest(Flag))
-        return true;
-      GVarFlags.MaybeWriteOnly = Flag;
-      break;
-    default:
-      return Error(Lex.getLoc(), "expected gvar flag type");
-    }
-  } while (EatIfPresent(lltok::comma));
-  return ParseToken(lltok::rparen, "expected ')' here");
+  if (ParseToken(lltok::rparen, "expected ')' here"))
+    return true;
+  return false;
 }
 
 /// ModuleReference
@@ -8806,9 +8783,7 @@ bool LLParser::ParseModuleReference(StringRef &ModulePath) {
 /// GVReference
 ///   ::= SummaryID
 bool LLParser::ParseGVReference(ValueInfo &VI, unsigned &GVId) {
-  bool WriteOnly = false, ReadOnly = EatIfPresent(lltok::kw_readonly);
-  if (!ReadOnly)
-    WriteOnly = EatIfPresent(lltok::kw_writeonly);
+  bool ReadOnly = EatIfPresent(lltok::kw_readonly);
   if (ParseToken(lltok::SummaryID, "expected GV ID"))
     return true;
 
@@ -8823,7 +8798,5 @@ bool LLParser::ParseGVReference(ValueInfo &VI, unsigned &GVId) {
 
   if (ReadOnly)
     VI.setReadOnly();
-  if (WriteOnly)
-    VI.setWriteOnly();
   return false;
 }