From f871d0cc377a1367b519a6cce26be74607566eba Mon Sep 17 00:00:00 2001
From: John McCall <rjmccall@apple.com>
Date: Sat, 7 Aug 2010 06:22:56 +0000
Subject: Store inheritance paths after CastExprs instead of inside them. This
 takes some trickery since CastExpr has subclasses (and indeed, is abstract).

Also, smoosh the CastKind into the bitfield from Expr.

Drops two words of storage from Expr in the common case of expressions
which don't need inheritance paths.  Avoids a separate allocation and
another word of overhead in cases needing inheritance paths.  Also has
the advantage of not leaking memory, since destructors for AST nodes are
never run.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@110507 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CGExpr.cpp | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

(limited to 'lib/CodeGen/CGExpr.cpp')

diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 173aadc91a..9424776898 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -142,7 +142,7 @@ struct SubobjectAdjustment {
   
   union {
     struct {
-      const CXXBaseSpecifierArray *BasePath;
+      const CastExpr *BasePath;
       const CXXRecordDecl *DerivedClass;
     } DerivedToBase;
     
@@ -152,7 +152,7 @@ struct SubobjectAdjustment {
     } Field;
   };
   
-  SubobjectAdjustment(const CXXBaseSpecifierArray *BasePath, 
+  SubobjectAdjustment(const CastExpr *BasePath, 
                       const CXXRecordDecl *DerivedClass)
     : Kind(DerivedToBaseAdjustment) 
   {
@@ -236,8 +236,7 @@ EmitExprForReferenceBinding(CodeGenFunction& CGF, const Expr* E,
           E = CE->getSubExpr();
           CXXRecordDecl *Derived 
             = cast<CXXRecordDecl>(E->getType()->getAs<RecordType>()->getDecl());
-          Adjustments.push_back(SubobjectAdjustment(&CE->getBasePath(), 
-                                                    Derived));
+          Adjustments.push_back(SubobjectAdjustment(CE, Derived));
           continue;
         }
 
@@ -291,7 +290,8 @@ EmitExprForReferenceBinding(CodeGenFunction& CGF, const Expr* E,
           Object = 
               CGF.GetAddressOfBaseClass(Object, 
                                         Adjustment.DerivedToBase.DerivedClass, 
-                                        *Adjustment.DerivedToBase.BasePath, 
+                              Adjustment.DerivedToBase.BasePath->path_begin(),
+                              Adjustment.DerivedToBase.BasePath->path_end(),
                                         /*NullCheckValue=*/false);
           break;
             
@@ -1820,7 +1820,8 @@ LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
     // Perform the derived-to-base conversion
     llvm::Value *Base = 
       GetAddressOfBaseClass(This, DerivedClassDecl, 
-                            E->getBasePath(), /*NullCheckValue=*/false);
+                            E->path_begin(), E->path_end(),
+                            /*NullCheckValue=*/false);
     
     return LValue::MakeAddr(Base, MakeQualifiers(E->getType()));
   }
@@ -1836,7 +1837,8 @@ LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
     // Perform the base-to-derived conversion
     llvm::Value *Derived = 
       GetAddressOfDerivedClass(LV.getAddress(), DerivedClassDecl, 
-                               E->getBasePath(),/*NullCheckValue=*/false);
+                               E->path_begin(), E->path_end(),
+                               /*NullCheckValue=*/false);
     
     return LValue::MakeAddr(Derived, MakeQualifiers(E->getType()));
   }
-- 
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