From a7911fa3d75a564356bdb3dae96f6c295f521b74 Mon Sep 17 00:00:00 2001 From: Anders Carlsson Date: Wed, 27 Oct 2010 13:28:46 +0000 Subject: If a virtual member function has the 'final' attribute, we can devirtualize calls to it. llvm-svn: 117444 --- clang/lib/CodeGen/CGExprCXX.cpp | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'clang/lib/CodeGen') diff --git a/clang/lib/CodeGen/CGExprCXX.cpp b/clang/lib/CodeGen/CGExprCXX.cpp index 750e609c855..e3b5f71b271 100644 --- a/clang/lib/CodeGen/CGExprCXX.cpp +++ b/clang/lib/CodeGen/CGExprCXX.cpp @@ -55,7 +55,14 @@ RValue CodeGenFunction::EmitCXXMemberCall(const CXXMethodDecl *MD, /// canDevirtualizeMemberFunctionCalls - Checks whether virtual calls on given /// expr can be devirtualized. -static bool canDevirtualizeMemberFunctionCalls(const Expr *Base) { +static bool canDevirtualizeMemberFunctionCalls(const Expr *Base, + const CXXMethodDecl *MD) { + + // If the member function has the "final" attribute, we know that it can't be + // overridden and can therefor devirtualize it. + if (MD->hasAttr()) + return true; + if (const DeclRefExpr *DRE = dyn_cast(Base)) { if (const VarDecl *VD = dyn_cast(DRE->getDecl())) { // This is a record decl. We know the type and can devirtualize it. @@ -76,7 +83,7 @@ static bool canDevirtualizeMemberFunctionCalls(const Expr *Base) { // Check if this is a call expr that returns a record type. if (const CallExpr *CE = dyn_cast(Base)) return CE->getCallReturnType()->isRecordType(); - + // We can't devirtualize the call. return false; } @@ -152,7 +159,7 @@ RValue CodeGenFunction::EmitCXXMemberCallExpr(const CXXMemberCallExpr *CE, // We also don't emit a virtual call if the base expression has a record type // because then we know what the type is. bool UseVirtualCall = MD->isVirtual() && !ME->hasQualifier() - && !canDevirtualizeMemberFunctionCalls(ME->getBase()); + && !canDevirtualizeMemberFunctionCalls(ME->getBase(), MD); llvm::Value *Callee; if (const CXXDestructorDecl *Dtor = dyn_cast(MD)) { @@ -267,7 +274,7 @@ CodeGenFunction::EmitCXXOperatorMemberCallExpr(const CXXOperatorCallExpr *E, This = LV.getAddress(); llvm::Value *Callee; - if (MD->isVirtual() && !canDevirtualizeMemberFunctionCalls(E->getArg(0))) + if (MD->isVirtual() && !canDevirtualizeMemberFunctionCalls(E->getArg(0), MD)) Callee = BuildVirtualCall(MD, This, Ty); else Callee = CGM.GetAddrOfFunction(MD, Ty); -- cgit v1.2.3