Remove compile time PreserveName switch based on NDEBUG

Summary:
Following r263086, we are now relying on a flag on the Context to
discard Value names in release builds.

Reviewers: chandlerc

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D18024

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 263257

clang/lib/CodeGen/CGBuilder.h

@@ -23,9 +23,7 @@ class CodeGenFunction;
 /// \brief This is an IRBuilder insertion helper that forwards to
 /// CodeGenFunction::InsertHelper, which adds necessary metadata to
 /// instructions.
-template <bool PreserveNames>
+class CGBuilderInserter : protected llvm::IRBuilderDefaultInserter {
-class CGBuilderInserter
-    : protected llvm::IRBuilderDefaultInserter<PreserveNames> {
 public:
   CGBuilderInserter() = default;
   explicit CGBuilderInserter(CodeGenFunction *CGF) : CGF(CGF) {}
@@ -39,17 +37,10 @@ private:
   CodeGenFunction *CGF = nullptr;
 };
 
-// Don't preserve names on values in an optimized build.
+typedef CGBuilderInserter CGBuilderInserterTy;
-#ifdef NDEBUG
-#define PreserveNames false
-#else
-#define PreserveNames true
-#endif
 
-typedef CGBuilderInserter<PreserveNames> CGBuilderInserterTy;
+typedef llvm::IRBuilder<llvm::ConstantFolder, CGBuilderInserterTy>
-
+    CGBuilderBaseTy;
-typedef llvm::IRBuilder<PreserveNames, llvm::ConstantFolder,
-                        CGBuilderInserterTy> CGBuilderBaseTy;
 
 class CGBuilderTy : public CGBuilderBaseTy {
   /// Storing a reference to the type cache here makes it a lot easier
@@ -305,8 +296,6 @@ public:
   }
 };
 
-#undef PreserveNames
-
 }  // end namespace CodeGen
 }  // end namespace clang
 

clang/lib/CodeGen/CGCall.cpp

@@ -3840,7 +3840,7 @@ RValue CodeGenFunction::EmitCall(const CGFunctionInfo &CallInfo,
   }
 
   llvm::Instruction *CI = CS.getInstruction();
-  if (Builder.isNamePreserving() && !CI->getType()->isVoidTy())
+  if (!CI->getType()->isVoidTy())
     CI->setName("call");
 
   // Emit any writebacks immediately.  Arguably this should happen

clang/lib/CodeGen/CGExpr.cpp

@@ -66,8 +66,6 @@ Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
 /// block.
 llvm::AllocaInst *CodeGenFunction::CreateTempAlloca(llvm::Type *Ty,
                                                     const Twine &Name) {
-  if (!Builder.isNamePreserving())
-    return new llvm::AllocaInst(Ty, nullptr, "", AllocaInsertPt);
   return new llvm::AllocaInst(Ty, nullptr, Name, AllocaInsertPt);
 }
 

clang/lib/CodeGen/CodeGenAction.cpp

@@ -656,7 +656,13 @@ void BackendConsumer::DiagnosticHandlerImpl(const DiagnosticInfo &DI) {
 
 CodeGenAction::CodeGenAction(unsigned _Act, LLVMContext *_VMContext)
     : Act(_Act), VMContext(_VMContext ? _VMContext : new LLVMContext),
-      OwnsVMContext(!_VMContext) {}
+      OwnsVMContext(!_VMContext) {
+#ifdef NDEBUG
+  // FIXME: change this to be controlled by a cc1 flag that the driver passes,
+  // on the model of --disable-free
+  _VMContext.setDiscardValueNames(true);
+#endif
+}
 
 CodeGenAction::~CodeGenAction() {
   TheModule.reset();

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -747,9 +747,7 @@ void CodeGenFunction::StartFunction(GlobalDecl GD,
   // later.  Don't create this with the builder, because we don't want it
   // folded.
   llvm::Value *Undef = llvm::UndefValue::get(Int32Ty);
-  AllocaInsertPt = new llvm::BitCastInst(Undef, Int32Ty, "", EntryBB);
+  AllocaInsertPt = new llvm::BitCastInst(Undef, Int32Ty, "allocapt", EntryBB);
-  if (Builder.isNamePreserving())
-    AllocaInsertPt->setName("allocapt");
 
   ReturnBlock = getJumpDestInCurrentScope("return");
 
@@ -1862,26 +1860,14 @@ void CodeGenFunction::InsertHelper(llvm::Instruction *I,
     CGM.getSanitizerMetadata()->disableSanitizerForInstruction(I);
 }
 
-template <bool PreserveNames>
+void CGBuilderInserter::InsertHelper(
-void CGBuilderInserter<PreserveNames>::InsertHelper(
     llvm::Instruction *I, const llvm::Twine &Name, llvm::BasicBlock *BB,
     llvm::BasicBlock::iterator InsertPt) const {
-  llvm::IRBuilderDefaultInserter<PreserveNames>::InsertHelper(I, Name, BB,
+  llvm::IRBuilderDefaultInserter::InsertHelper(I, Name, BB, InsertPt);
-                                                              InsertPt);
   if (CGF)
     CGF->InsertHelper(I, Name, BB, InsertPt);
 }
 
-#ifdef NDEBUG
-#define PreserveNames false
-#else
-#define PreserveNames true
-#endif
-template void CGBuilderInserter<PreserveNames>::InsertHelper(
-    llvm::Instruction *I, const llvm::Twine &Name, llvm::BasicBlock *BB,
-    llvm::BasicBlock::iterator InsertPt) const;
-#undef PreserveNames
-
 static bool hasRequiredFeatures(const SmallVectorImpl<StringRef> &ReqFeatures,
                                 CodeGenModule &CGM, const FunctionDecl *FD,
                                 std::string &FirstMissing) {