[PGO] Eliminate prof data register calls on FreeBSD platform

[oota-llvm.git] / lib / Transforms / Instrumentation / InstrProfiling.cpp

diff --git a/lib/Transforms/Instrumentation/InstrProfiling.cpp b/lib/Transforms/Instrumentation/InstrProfiling.cpp
index 2a3d15421de9dec58b646bbc0377a7449c541ae6..a68fd3db6c2e9238ae04bec683a68c38b73f6d1a 100644 (file)
--- a/lib/Transforms/Instrumentation/InstrProfiling.cpp
+++ b/lib/Transforms/Instrumentation/InstrProfiling.cpp
@@ -97,7 +97,8 @@ private:
   /// Add uses of our data variables and runtime hook.
   void emitUses();
 
-  /// Create a static initializer for our data, on platforms that need it.
+  /// Create a static initializer for our data, on platforms that need it,
+  /// and for any profile output file that was specified.
   void emitInitialization();
 };
 
@@ -143,10 +144,10 @@ bool InstrProfiling::runOnModule(Module &M) {
 void InstrProfiling::lowerIncrement(InstrProfIncrementInst *Inc) {
   GlobalVariable *Counters = getOrCreateRegionCounters(Inc);
 
-  IRBuilder<> Builder(Inc->getParent(), *Inc);
+  IRBuilder<> Builder(Inc);
   uint64_t Index = Inc->getIndex()->getZExtValue();
-  llvm::Value *Addr = Builder.CreateConstInBoundsGEP2_64(Counters, 0, Index);
-  llvm::Value *Count = Builder.CreateLoad(Addr, "pgocount");
+  Value *Addr = Builder.CreateConstInBoundsGEP2_64(Counters, 0, Index);
+  Value *Count = Builder.CreateLoad(Addr, "pgocount");
   Count = Builder.CreateAdd(Count, Builder.getInt64(1));
   Inc->replaceAllUsesWith(Builder.CreateStore(Count, Addr));
   Inc->eraseFromParent();
@@ -195,9 +196,17 @@ InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
   if (It != RegionCounters.end())
     return It->second;
 
-  // Move the name variable to the right section.
+  // Move the name variable to the right section. Place them in a COMDAT group
+  // if the associated function is a COMDAT. This will make sure that
+  // only one copy of counters of the COMDAT function will be emitted after
+  // linking.
+  Function *Fn = Inc->getParent()->getParent();
+  Comdat *ProfileVarsComdat = nullptr;
+  if (Fn->hasComdat())
+    ProfileVarsComdat = M->getOrInsertComdat(StringRef(getVarName(Inc, "vars")));
   Name->setSection(getNameSection());
   Name->setAlignment(1);
+  Name->setComdat(ProfileVarsComdat);
 
   uint64_t NumCounters = Inc->getNumCounters()->getZExtValue();
   LLVMContext &Ctx = M->getContext();
@@ -210,6 +219,7 @@ InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
   Counters->setVisibility(Name->getVisibility());
   Counters->setSection(getCountersSection());
   Counters->setAlignment(8);
+  Counters->setComdat(ProfileVarsComdat);
 
   RegionCounters[Inc->getName()] = Counters;
 
@@ -234,6 +244,7 @@ InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
   Data->setVisibility(Name->getVisibility());
   Data->setSection(getDataSection());
   Data->setAlignment(8);
+  Data->setComdat(ProfileVarsComdat);
 
   // Mark the data variable as used so that it isn't stripped out.
   UsedVars.push_back(Data);
@@ -246,6 +257,11 @@ void InstrProfiling::emitRegistration() {
   if (Triple(M->getTargetTriple()).isOSDarwin())
     return;
 
+  // Use linker script magic to get data/cnts/name start/end.
+  if (Triple(M->getTargetTriple()).isOSLinux() ||
+      Triple(M->getTargetTriple()).isOSFreeBSD())
+    return;
+
   // Construct the function.
   auto *VoidTy = Type::getVoidTy(M->getContext());
   auto *VoidPtrTy = Type::getInt8PtrTy(M->getContext());
@@ -256,7 +272,7 @@ void InstrProfiling::emitRegistration() {
   if (Options.NoRedZone)
     RegisterF->addFnAttr(Attribute::NoRedZone);
 
-  auto *RuntimeRegisterTy = llvm::FunctionType::get(VoidTy, VoidPtrTy, false);
+  auto *RuntimeRegisterTy = FunctionType::get(VoidTy, VoidPtrTy, false);
   auto *RuntimeRegisterF =
       Function::Create(RuntimeRegisterTy, GlobalVariable::ExternalLinkage,
                        "__llvm_profile_register_function", M);
@@ -288,6 +304,7 @@ void InstrProfiling::emitRuntimeHook() {
   User->addFnAttr(Attribute::NoInline);
   if (Options.NoRedZone)
     User->addFnAttr(Attribute::NoRedZone);
+  User->setVisibility(GlobalValue::HiddenVisibility);
 
   IRBuilder<> IRB(BasicBlock::Create(M->getContext(), "", User));
   auto *Load = IRB.CreateLoad(Var);
@@ -302,7 +319,7 @@ void InstrProfiling::emitUses() {
     return;
 
   GlobalVariable *LLVMUsed = M->getGlobalVariable("llvm.used");
-  std::vector<Constant*> MergedVars;
+  std::vector<Constant *> MergedVars;
   if (LLVMUsed) {
     // Collect the existing members of llvm.used.
     ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
@@ -315,20 +332,22 @@ void InstrProfiling::emitUses() {
   // Add uses for our data.
   for (auto *Value : UsedVars)
     MergedVars.push_back(
-        ConstantExpr::getBitCast(cast<llvm::Constant>(Value), i8PTy));
+        ConstantExpr::getBitCast(cast<Constant>(Value), i8PTy));
 
   // Recreate llvm.used.
   ArrayType *ATy = ArrayType::get(i8PTy, MergedVars.size());
-  LLVMUsed = new llvm::GlobalVariable(
-      *M, ATy, false, llvm::GlobalValue::AppendingLinkage,
-      llvm::ConstantArray::get(ATy, MergedVars), "llvm.used");
+  LLVMUsed =
+      new GlobalVariable(*M, ATy, false, GlobalValue::AppendingLinkage,
+                         ConstantArray::get(ATy, MergedVars), "llvm.used");
 
   LLVMUsed->setSection("llvm.metadata");
 }
 
 void InstrProfiling::emitInitialization() {
+  std::string InstrProfileOutput = Options.InstrProfileOutput;
+
   Constant *RegisterF = M->getFunction("__llvm_profile_register_functions");
-  if (!RegisterF)
+  if (!RegisterF && InstrProfileOutput.empty())
     return;
 
   // Create the initialization function.
@@ -343,7 +362,24 @@ void InstrProfiling::emitInitialization() {
 
   // Add the basic block and the necessary calls.
   IRBuilder<> IRB(BasicBlock::Create(M->getContext(), "", F));
-  IRB.CreateCall(RegisterF);
+  if (RegisterF)
+    IRB.CreateCall(RegisterF, {});
+  if (!InstrProfileOutput.empty()) {
+    auto *Int8PtrTy = Type::getInt8PtrTy(M->getContext());
+    auto *SetNameTy = FunctionType::get(VoidTy, Int8PtrTy, false);
+    auto *SetNameF =
+        Function::Create(SetNameTy, GlobalValue::ExternalLinkage,
+                         "__llvm_profile_override_default_filename", M);
+
+    // Create variable for profile name.
+    Constant *ProfileNameConst =
+        ConstantDataArray::getString(M->getContext(), InstrProfileOutput, true);
+    GlobalVariable *ProfileName =
+        new GlobalVariable(*M, ProfileNameConst->getType(), true,
+                           GlobalValue::PrivateLinkage, ProfileNameConst);
+
+    IRB.CreateCall(SetNameF, IRB.CreatePointerCast(ProfileName, Int8PtrTy));
+  }
   IRB.CreateRetVoid();
 
   appendToGlobalCtors(*M, F, 0);