1 files changed, 15 insertions, 50 deletions

diff --git a/llvm/include/llvm/IR/ModuleSummaryIndex.h b/llvm/include/llvm/IR/ModuleSummaryIndex.h
index a81338e576a..c931842fd46 100644
--- a/llvm/include/llvm/IR/ModuleSummaryIndex.h
+++ b/llvm/include/llvm/IR/ModuleSummaryIndex.h
@@ -162,8 +162,7 @@ using GlobalValueSummaryMapTy =
 /// Struct that holds a reference to a particular GUID in a global value
 /// summary.
 struct ValueInfo {
-  enum Flags { HaveGV = 1, ReadOnly = 2, WriteOnly = 4 };
-  PointerIntPair<const GlobalValueSummaryMapTy::value_type *, 3, int>
+  PointerIntPair<const GlobalValueSummaryMapTy::value_type *, 2, int>
       RefAndFlags;
 
   ValueInfo() = default;
@@ -189,33 +188,9 @@ struct ValueInfo {
                      : getRef()->second.U.Name;
   }
 
-  bool haveGVs() const { return RefAndFlags.getInt() & HaveGV; }
-  bool isReadOnly() const {
-    assert(isValidAccessSpecifier());
-    return RefAndFlags.getInt() & ReadOnly;
-  }
-  bool isWriteOnly() const {
-    assert(isValidAccessSpecifier());
-    return RefAndFlags.getInt() & WriteOnly;
-  }
-  unsigned getAccessSpecifier() const {
-    assert(isValidAccessSpecifier());
-    return RefAndFlags.getInt() & (ReadOnly | WriteOnly);
-  }
-  bool isValidAccessSpecifier() const {
-    unsigned BadAccessMask = ReadOnly | WriteOnly;
-    return (RefAndFlags.getInt() & BadAccessMask) != BadAccessMask;
-  }
-  void setReadOnly() {
-    // We expect ro/wo attribute to set only once during
-    // ValueInfo lifetime.
-    assert(getAccessSpecifier() == 0);
-    RefAndFlags.setInt(RefAndFlags.getInt() | ReadOnly);
-  }
-  void setWriteOnly() {
-    assert(getAccessSpecifier() == 0);
-    RefAndFlags.setInt(RefAndFlags.getInt() | WriteOnly);
-  }
+  bool haveGVs() const { return RefAndFlags.getInt() & 0x1; }
+  bool isReadOnly() const { return RefAndFlags.getInt() & 0x2; }
+  void setReadOnly() { RefAndFlags.setInt(RefAndFlags.getInt() | 0x2); }
 
   const GlobalValueSummaryMapTy::value_type *getRef() const {
     return RefAndFlags.getPointer();
@@ -609,8 +584,8 @@ public:
           std::move(TypeTestAssumeConstVCalls),
           std::move(TypeCheckedLoadConstVCalls)});
   }
-  // Gets the number of readonly and writeonly refs in RefEdgeList
-  std::pair<unsigned, unsigned> specialRefCounts() const;
+  // Gets the number of immutable refs in RefEdgeList
+  unsigned immutableRefCount() const;
 
   /// Check if this is a function summary.
   static bool classof(const GlobalValueSummary *GVS) {
@@ -738,12 +713,9 @@ using VTableFuncList = std::vector<VirtFuncOffset>;
 /// Global variable summary information to aid decisions and
 /// implementation of importing.
 ///
-/// Global variable summary has two extra flag, telling if it is
-/// readonly or writeonly. Both readonly and writeonly variables
-/// can be optimized in the backed: readonly variables can be
-/// const-folded, while writeonly vars can be completely eliminated
-/// together with corresponding stores. We let both things happen
-/// by means of internalizing such variables after ThinLTO import.
+/// Global variable summary has extra flag, telling if it is
+/// modified during the program run or not. This affects ThinLTO
+/// internalization
 class GlobalVarSummary : public GlobalValueSummary {
 private:
   /// For vtable definitions this holds the list of functions and
@@ -752,14 +724,9 @@ private:
 
 public:
   struct GVarFlags {
-    GVarFlags(bool ReadOnly, bool WriteOnly)
-        : MaybeReadOnly(ReadOnly), MaybeWriteOnly(WriteOnly) {}
-
-    // In permodule summaries both MaybeReadOnly and MaybeWriteOnly
-    // bits are set, because attribute propagation occurs later on
-    // thin link phase.
-    unsigned MaybeReadOnly : 1;
-    unsigned MaybeWriteOnly : 1;
+    GVarFlags(bool ReadOnly = false) : ReadOnly(ReadOnly) {}
+
+    unsigned ReadOnly : 1;
   } VarFlags;
 
   GlobalVarSummary(GVFlags Flags, GVarFlags VarFlags,
@@ -773,10 +740,8 @@ public:
   }
 
   GVarFlags varflags() const { return VarFlags; }
-  void setReadOnly(bool RO) { VarFlags.MaybeReadOnly = RO; }
-  void setWriteOnly(bool WO) { VarFlags.MaybeWriteOnly = WO; }
-  bool maybeReadOnly() const { return VarFlags.MaybeReadOnly; }
-  bool maybeWriteOnly() const { return VarFlags.MaybeWriteOnly; }
+  void setReadOnly(bool RO) { VarFlags.ReadOnly = RO; }
+  bool isReadOnly() const { return VarFlags.ReadOnly; }
 
   void setVTableFuncs(VTableFuncList Funcs) {
     assert(!VTableFuncs);
@@ -1347,7 +1312,7 @@ public:
   void dumpSCCs(raw_ostream &OS);
 
   /// Analyze index and detect unmodified globals
-  void propagateAttributes(const DenseSet<GlobalValue::GUID> &PreservedSymbols);
+  void propagateConstants(const DenseSet<GlobalValue::GUID> &PreservedSymbols);
 };
 
 /// GraphTraits definition to build SCC for the index