[CodeGen] Align rtti and vtable data

Previously the alignment on the newly created rtti/typeinfo data was largely
not set, meaning that DataLayout::getPreferredAlignment was free to overalign
it to 16 bytes. This causes unnecessary code bloat.

Differential Revision: https://reviews.llvm.org/D51416

llvm-svn: 342053

1 files changed, 5 insertions, 4 deletions

diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp
index 5fec6c7..6d42b3c 100644
--- a/clang/lib/CodeGen/CodeGenModule.cpp
+++ b/clang/lib/CodeGen/CodeGenModule.cpp
@@ -3099,10 +3099,9 @@ CodeGenModule::GetAddrOfGlobal(GlobalDecl GD,
                               IsForDefinition);
 }
 
-llvm::GlobalVariable *
-CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name,
-                                      llvm::Type *Ty,
-                                      llvm::GlobalValue::LinkageTypes Linkage) {
+llvm::GlobalVariable *CodeGenModule::CreateOrReplaceCXXRuntimeVariable(
+    StringRef Name, llvm::Type *Ty, llvm::GlobalValue::LinkageTypes Linkage,
+    unsigned Alignment) {
   llvm::GlobalVariable *GV = getModule().getNamedGlobal(Name);
   llvm::GlobalVariable *OldGV = nullptr;
 
@@ -3138,6 +3137,8 @@ CodeGenModule::CreateOrReplaceCXXRuntimeVariable(StringRef Name,
       !GV->hasAvailableExternallyLinkage())
     GV->setComdat(TheModule.getOrInsertComdat(GV->getName()));
 
+  GV->setAlignment(Alignment);
+
   return GV;
 }