Move the state bits in DeclRefExpr out of the pointer union and into

a bitfield in the base class. DREs weren't using any bits here past the
normal Expr bits, so we have plenty of room. This makes the common case
of getting a Decl out of a DRE no longer need to do any masking etc.

Also, while here, clean up code to use the accessor methods rather than
directly poking these bits, and provide a nice comment for DREs that
includes the information previously attached to the bits going into the
pointer union.

No functionality changed here, but DREs should be a tad faster now.

llvm-svn: 130666

2 files changed, 15 insertions, 19 deletions

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 2a5917c4594..cd5a63aab51 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -279,17 +279,18 @@ DeclRefExpr::DeclRefExpr(NestedNameSpecifierLoc QualifierLoc,
                          const TemplateArgumentListInfo *TemplateArgs,
                          QualType T, ExprValueKind VK)
   : Expr(DeclRefExprClass, T, VK, OK_Ordinary, false, false, false),
-    DecoratedD(D,
-               (QualifierLoc? HasQualifierFlag : 0) |
-               (TemplateArgs ? HasExplicitTemplateArgumentListFlag : 0)),
-    Loc(NameLoc) {
+    D(D), Loc(NameLoc) {
+  DeclRefExprBits.HasQualifier = QualifierLoc ? 1 : 0;
   if (QualifierLoc) {
+    DeclRefExprBits.HasQualifier = 1;
     NameQualifier *NQ = getNameQualifier();
     NQ->QualifierLoc = QualifierLoc;
   }
-      
-  if (TemplateArgs)
+
+  DeclRefExprBits.HasExplicitTemplateArgs = TemplateArgs ? 1 : 0;
+  if (TemplateArgs) {
     getExplicitTemplateArgs().initializeFrom(*TemplateArgs);
+  }
 
   computeDependence();
 }
@@ -299,15 +300,14 @@ DeclRefExpr::DeclRefExpr(NestedNameSpecifierLoc QualifierLoc,
                          const TemplateArgumentListInfo *TemplateArgs,
                          QualType T, ExprValueKind VK)
   : Expr(DeclRefExprClass, T, VK, OK_Ordinary, false, false, false),
-    DecoratedD(D,
-               (QualifierLoc? HasQualifierFlag : 0) |
-               (TemplateArgs ? HasExplicitTemplateArgumentListFlag : 0)),
-    Loc(NameInfo.getLoc()), DNLoc(NameInfo.getInfo()) {
+    D(D), Loc(NameInfo.getLoc()), DNLoc(NameInfo.getInfo()) {
+  DeclRefExprBits.HasQualifier = QualifierLoc ? 1 : 0;
   if (QualifierLoc) {
     NameQualifier *NQ = getNameQualifier();
     NQ->QualifierLoc = QualifierLoc;
   }
 
+  DeclRefExprBits.HasExplicitTemplateArgs = TemplateArgs ? 1 : 0;
   if (TemplateArgs)
     getExplicitTemplateArgs().initializeFrom(*TemplateArgs);
 
diff --git a/clang/lib/Serialization/ASTReaderStmt.cpp b/clang/lib/Serialization/ASTReaderStmt.cpp
index 83b3907f581..f0b5abaf3bf 100644
--- a/clang/lib/Serialization/ASTReaderStmt.cpp
+++ b/clang/lib/Serialization/ASTReaderStmt.cpp
@@ -425,21 +425,17 @@ void ASTStmtReader::VisitPredefinedExpr(PredefinedExpr *E) {
 void ASTStmtReader::VisitDeclRefExpr(DeclRefExpr *E) {
   VisitExpr(E);
 
-  bool HasQualifier = Record[Idx++];
-  bool HasExplicitTemplateArgs = Record[Idx++];
+  E->DeclRefExprBits.HasQualifier = Record[Idx++];
+  E->DeclRefExprBits.HasExplicitTemplateArgs = Record[Idx++];
   unsigned NumTemplateArgs = 0;
-  if (HasExplicitTemplateArgs)
+  if (E->hasExplicitTemplateArgs())
     NumTemplateArgs = Record[Idx++];
 
-  E->DecoratedD.setInt((HasQualifier? DeclRefExpr::HasQualifierFlag : 0) |
-      (HasExplicitTemplateArgs 
-         ? DeclRefExpr::HasExplicitTemplateArgumentListFlag : 0));
-  
-  if (HasQualifier)
+  if (E->hasQualifier())
     E->getNameQualifier()->QualifierLoc
       = Reader.ReadNestedNameSpecifierLoc(F, Record, Idx);
 
-  if (HasExplicitTemplateArgs)
+  if (E->hasExplicitTemplateArgs())
     ReadExplicitTemplateArgumentList(E->getExplicitTemplateArgs(),
                                      NumTemplateArgs);