Decorating vptr load & stores with !invariant.group

Adding !invariant.group to vptr load/stores for devirtualization purposes.
For more goto:
http://lists.llvm.org/pipermail/cfe-dev/2015-July/044227.html

http://reviews.llvm.org/D12026

llvm-svn: 247725

1 files changed, 13 insertions, 3 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index d9bb24e..bb3bbf2 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -507,9 +507,9 @@ llvm::MDNode *CodeGenModule::getTBAAStructTagInfo(QualType BaseTy,
 /// and struct-path aware TBAA, the tag has the same format:
 /// base type, access type and offset.
 /// When ConvertTypeToTag is true, we create a tag based on the scalar type.
-void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst,
-                                        llvm::MDNode *TBAAInfo,
-                                        bool ConvertTypeToTag) {
+void CodeGenModule::DecorateInstructionWithTBAA(llvm::Instruction *Inst,
+                                                llvm::MDNode *TBAAInfo,
+                                                bool ConvertTypeToTag) {
   if (ConvertTypeToTag && TBAA)
     Inst->setMetadata(llvm::LLVMContext::MD_tbaa,
                       TBAA->getTBAAScalarTagInfo(TBAAInfo));
@@ -517,6 +517,16 @@ void CodeGenModule::DecorateInstruction(llvm::Instruction *Inst,
     Inst->setMetadata(llvm::LLVMContext::MD_tbaa, TBAAInfo);
 }
 
+void CodeGenModule::DecorateInstructionWithInvariantGroup(
+    llvm::Instruction *I, const CXXRecordDecl *RD) {
+  llvm::Metadata *MD = CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0));
+  auto *MetaDataNode = dyn_cast<llvm::MDNode>(MD);
+  // Check if we have to wrap MDString in MDNode.
+  if (!MetaDataNode)
+    MetaDataNode = llvm::MDNode::get(getLLVMContext(), MD);
+  I->setMetadata("invariant.group", MetaDataNode);
+}
+
 void CodeGenModule::Error(SourceLocation loc, StringRef message) {
   unsigned diagID = getDiags().getCustomDiagID(DiagnosticsEngine::Error, "%0");
   getDiags().Report(Context.getFullLoc(loc), diagID) << message;