InstrProf: An intrinsic and lowering for instrumentation based profiling
authorJustin Bogner <mail@justinbogner.com>
Mon, 8 Dec 2014 18:02:35 +0000 (18:02 +0000)
committerJustin Bogner <mail@justinbogner.com>
Mon, 8 Dec 2014 18:02:35 +0000 (18:02 +0000)
Introduce the ``llvm.instrprof_increment`` intrinsic and the
``-instrprof`` pass. These provide the infrastructure for writing
counters for profiling, as in clang's ``-fprofile-instr-generate``.

The implementation of the instrprof pass is ported directly out of the
CodeGenPGO classes in clang, and with the followup in clang that rips
that code out to use these new intrinsics this ends up being NFC.

Doing the instrumentation this way opens some doors in terms of
improving the counter performance. For example, this will make it
simple to experiment with alternate lowering strategies, and allows us
to try handling profiling specially in some optimizations if we want
to.

Finally, this drastically simplifies the frontend and puts all of the
lowering logic in one place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223672 91177308-0d34-0410-b5e6-96231b3b80d8

14 files changed:
docs/LangRef.rst
include/llvm/IR/IntrinsicInst.h
include/llvm/IR/Intrinsics.td
include/llvm/InitializePasses.h
include/llvm/LinkAllPasses.h
include/llvm/Transforms/Instrumentation.h
lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
lib/Transforms/Instrumentation/CMakeLists.txt
lib/Transforms/Instrumentation/InstrProfiling.cpp [new file with mode: 0644]
lib/Transforms/Instrumentation/Instrumentation.cpp
test/Instrumentation/InstrProfiling/no-counters.ll [new file with mode: 0644]
test/Instrumentation/InstrProfiling/noruntime.ll [new file with mode: 0644]
test/Instrumentation/InstrProfiling/platform.ll [new file with mode: 0644]
test/Instrumentation/InstrProfiling/profiling.ll [new file with mode: 0644]

index 3412ed31015003202baa98d008b3794959085629..181514962c90fd87a45f6da48e920e9efa9ff601 100644 (file)
@@ -7492,6 +7492,50 @@ time library.
 This instrinsic does *not* empty the instruction pipeline. Modifications
 of the current function are outside the scope of the intrinsic.
 
+'``llvm.instrprof_increment``' Intrinsic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+      declare void @llvm.instrprof_increment(i8* <name>, i64 <hash>,
+                                             i32 <num-counters>, i32 <index>)
+
+Overview:
+"""""""""
+
+The '``llvm.instrprof_increment``' intrinsic can be emitted by a
+frontend for use with instrumentation based profiling. These will be
+lowered by the ``-instrprof`` pass to generate execution counts of a
+program at runtime.
+
+Arguments:
+""""""""""
+
+The first argument is a pointer to a global variable containing the
+name of the entity being instrumented. This should generally be the
+(mangled) function name for a set of counters.
+
+The second argument is a hash value that can be used by the consumer
+of the profile data to detect changes to the instrumented source, and
+the third is the number of counters associated with ``name``. It is an
+error if ``hash`` or ``num-counters`` differ between two instances of
+``instrprof_increment`` that refer to the same name.
+
+The last argument refers to which of the counters for ``name`` should
+be incremented. It should be a value between 0 and ``num-counters``.
+
+Semantics:
+""""""""""
+
+This intrinsic represents an increment of a profiling counter. It will
+cause the ``-instrprof`` pass to generate the appropriate data
+structures and the code to increment the appropriate value, in a
+format that can be written out by a compiler runtime and consumed via
+the ``llvm-profdata`` tool.
+
 Standard C Library Intrinsics
 -----------------------------
 
index e3d799984542f47d5b1e974a743d4b868113a580..d4cb67af7285c71b49e853dec81f7e71a95effaa 100644 (file)
@@ -322,6 +322,33 @@ namespace llvm {
     Value *getSrc() const { return const_cast<Value*>(getArgOperand(1)); }
   };
 
+  /// This represents the llvm.instrprof_increment intrinsic.
+  class InstrProfIncrementInst : public IntrinsicInst {
+  public:
+    static inline bool classof(const IntrinsicInst *I) {
+      return I->getIntrinsicID() == Intrinsic::instrprof_increment;
+    }
+    static inline bool classof(const Value *V) {
+      return isa<IntrinsicInst>(V) && classof(cast<IntrinsicInst>(V));
+    }
+
+    GlobalVariable *getName() const {
+      return cast<GlobalVariable>(
+          const_cast<Value *>(getArgOperand(0))->stripPointerCasts());
+    }
+
+    ConstantInt *getHash() const {
+      return cast<ConstantInt>(const_cast<Value *>(getArgOperand(1)));
+    }
+
+    ConstantInt *getNumCounters() const {
+      return cast<ConstantInt>(const_cast<Value *>(getArgOperand(2)));
+    }
+
+    ConstantInt *getIndex() const {
+      return cast<ConstantInt>(const_cast<Value *>(getArgOperand(3)));
+    }
+  };
 }
 
 #endif
index 08bdf3a264218a7093f1ff44e31190b3e924dd24..902f3b3187a305937dae1c848c69f73e5ca4991c 100644 (file)
@@ -291,6 +291,12 @@ def int_stackprotector : Intrinsic<[], [llvm_ptr_ty, llvm_ptrptr_ty], []>;
 def int_stackprotectorcheck : Intrinsic<[], [llvm_ptrptr_ty],
                                         [IntrReadWriteArgMem]>;
 
+// A counter increment for instrumentation based profiling.
+def int_instrprof_increment : Intrinsic<[],
+                                        [llvm_ptr_ty, llvm_i64_ty,
+                                         llvm_i32_ty, llvm_i32_ty],
+                                        []>;
+
 //===------------------- Standard C Library Intrinsics --------------------===//
 //
 
index edce794c2865c5d7f828a9d6a0034dabbc53f2a4..2b99e1b288868c9909e247654e0f824715ecc87b 100644 (file)
@@ -121,6 +121,7 @@ void initializeEarlyIfConverterPass(PassRegistry&);
 void initializeEdgeBundlesPass(PassRegistry&);
 void initializeExpandPostRAPass(PassRegistry&);
 void initializeGCOVProfilerPass(PassRegistry&);
+void initializeInstrProfilingPass(PassRegistry&);
 void initializeAddressSanitizerPass(PassRegistry&);
 void initializeAddressSanitizerModulePass(PassRegistry&);
 void initializeMemorySanitizerPass(PassRegistry&);
index 2c16c8ca4d944ba0f6478b40232ebecc89783900..fad38654b48b9c2e236dae0c790c827a76a5ec00 100644 (file)
@@ -78,6 +78,7 @@ namespace {
       (void) llvm::createDomOnlyViewerPass();
       (void) llvm::createDomViewerPass();
       (void) llvm::createGCOVProfilerPass();
+      (void) llvm::createInstrProfilingPass();
       (void) llvm::createFunctionInliningPass();
       (void) llvm::createAlwaysInlinerPass();
       (void) llvm::createGlobalDCEPass();
index 4737cb3b0beb94cdbf3853fc93f20cf1f067ab62..24e3ef783ee62e6951d8db1f599c6a0212e42ed9 100644 (file)
@@ -63,6 +63,18 @@ struct GCOVOptions {
 ModulePass *createGCOVProfilerPass(const GCOVOptions &Options =
                                    GCOVOptions::getDefault());
 
+/// Options for the frontend instrumentation based profiling pass.
+struct InstrProfOptions {
+  InstrProfOptions() : NoRedZone(false) {}
+
+  // Add the 'noredzone' attribute to added runtime library calls.
+  bool NoRedZone;
+};
+
+/// Insert frontend instrumentation based profiling.
+ModulePass *createInstrProfilingPass(
+    const InstrProfOptions &Options = InstrProfOptions());
+
 // Insert AddressSanitizer (address sanity checking) instrumentation
 FunctionPass *createAddressSanitizerFunctionPass();
 ModulePass *createAddressSanitizerModulePass();
index a5fdfc55487763274d2d393d67d0e6c106665043..cab3cbf8ab56a99498e00d7f3151c092d2c0815c 100644 (file)
@@ -5570,6 +5570,8 @@ SelectionDAGBuilder::visitIntrinsicCall(const CallInst &I, unsigned Intrinsic) {
     visitGCRelocate(I);
     return nullptr;
   }
+  case Intrinsic::instrprof_increment:
+    llvm_unreachable("instrprof failed to lower an increment");
   }
 }
 
index a6a3106041ff52b9db9abe748250c0bc23a8d21b..92e1091aa3b1a8bc8a4c5602986632bece60eb12 100644 (file)
@@ -5,6 +5,7 @@ add_llvm_library(LLVMInstrumentation
   GCOVProfiling.cpp
   MemorySanitizer.cpp
   Instrumentation.cpp
+  InstrProfiling.cpp
   SanitizerCoverage.cpp
   ThreadSanitizer.cpp
   )
diff --git a/lib/Transforms/Instrumentation/InstrProfiling.cpp b/lib/Transforms/Instrumentation/InstrProfiling.cpp
new file mode 100644 (file)
index 0000000..5f73b89
--- /dev/null
@@ -0,0 +1,309 @@
+//===-- InstrProfiling.cpp - Frontend instrumentation based profiling -----===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass lowers instrprof_increment intrinsics emitted by a frontend for
+// profiling. It also builds the data structures and initialization code needed
+// for updating execution counts and emitting the profile at runtime.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/Instrumentation.h"
+
+#include "llvm/ADT/Triple.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Transforms/Utils/ModuleUtils.h"
+
+using namespace llvm;
+
+#define DEBUG_TYPE "instrprof"
+
+namespace {
+
+class InstrProfiling : public ModulePass {
+public:
+  static char ID;
+
+  InstrProfiling() : ModulePass(ID) {}
+
+  InstrProfiling(const InstrProfOptions &Options)
+      : ModulePass(ID), Options(Options) {}
+
+  const char *getPassName() const override {
+    return "Frontend instrumentation-based coverage lowering";
+  }
+
+  bool runOnModule(Module &M) override;
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.setPreservesCFG();
+  }
+
+private:
+  InstrProfOptions Options;
+  Module *M;
+  DenseMap<GlobalVariable *, GlobalVariable *> RegionCounters;
+  std::vector<Value *> UsedVars;
+
+  bool isMachO() const {
+    return Triple(M->getTargetTriple()).isOSBinFormatMachO();
+  }
+
+  /// Get the section name for the counter variables.
+  StringRef getCountersSection() const {
+    return isMachO() ? "__DATA,__llvm_prf_cnts" : "__llvm_prf_cnts";
+  }
+
+  /// Get the section name for the name variables.
+  StringRef getNameSection() const {
+    return isMachO() ? "__DATA,__llvm_prf_names" : "__llvm_prf_names";
+  }
+
+  /// Get the section name for the profile data variables.
+  StringRef getDataSection() const {
+    return isMachO() ? "__DATA,__llvm_prf_data" : "__llvm_prf_data";
+  }
+
+  /// Replace instrprof_increment with an increment of the appropriate value.
+  void lowerIncrement(InstrProfIncrementInst *Inc);
+
+  /// Get the region counters for an increment, creating them if necessary.
+  ///
+  /// If the counter array doesn't yet exist, the profile data variables
+  /// referring to them will also be created.
+  GlobalVariable *getOrCreateRegionCounters(InstrProfIncrementInst *Inc);
+
+  /// Emit runtime registration functions for each profile data variable.
+  void emitRegistration();
+
+  /// Emit the necessary plumbing to pull in the runtime initialization.
+  void emitRuntimeHook();
+
+  /// Add uses of our data variables and runtime hook.
+  void emitUses();
+
+  /// Create a static initializer for our data, on platforms that need it.
+  void emitInitialization();
+};
+
+} // anonymous namespace
+
+char InstrProfiling::ID = 0;
+INITIALIZE_PASS(InstrProfiling, "instrprof",
+                "Frontend instrumentation-based coverage lowering.", false,
+                false)
+
+ModulePass *llvm::createInstrProfilingPass(const InstrProfOptions &Options) {
+  return new InstrProfiling(Options);
+}
+
+bool InstrProfiling::runOnModule(Module &M) {
+  bool MadeChange = false;
+
+  this->M = &M;
+  RegionCounters.clear();
+  UsedVars.clear();
+
+  for (Function &F : M)
+    for (BasicBlock &BB : F)
+      for (auto I = BB.begin(), E = BB.end(); I != E;)
+        if (auto *Inc = dyn_cast<InstrProfIncrementInst>(I++)) {
+          lowerIncrement(Inc);
+          MadeChange = true;
+        }
+  if (!MadeChange)
+    return false;
+
+  emitRegistration();
+  emitRuntimeHook();
+  emitUses();
+  emitInitialization();
+  return true;
+}
+
+void InstrProfiling::lowerIncrement(InstrProfIncrementInst *Inc) {
+  GlobalVariable *Counters = getOrCreateRegionCounters(Inc);
+
+  IRBuilder<> Builder(Inc->getParent(), *Inc);
+  uint64_t Index = Inc->getIndex()->getZExtValue();
+  llvm::Value *Addr = Builder.CreateConstInBoundsGEP2_64(Counters, 0, Index);
+  llvm::Value *Count = Builder.CreateLoad(Addr, "pgocount");
+  Count = Builder.CreateAdd(Count, Builder.getInt64(1));
+  Inc->replaceAllUsesWith(Builder.CreateStore(Count, Addr));
+  Inc->eraseFromParent();
+}
+
+/// Get the name of a profiling variable for a particular function.
+static std::string getVarName(InstrProfIncrementInst *Inc, StringRef VarName) {
+  auto *Arr = cast<ConstantDataArray>(Inc->getName()->getInitializer());
+  StringRef Name = Arr->isCString() ? Arr->getAsCString() : Arr->getAsString();
+  return ("__llvm_profile_" + VarName + "_" + Name).str();
+}
+
+GlobalVariable *
+InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
+  GlobalVariable *Name = Inc->getName();
+  auto It = RegionCounters.find(Name);
+  if (It != RegionCounters.end())
+    return It->second;
+
+  // Move the name variable to the right section.
+  Name->setSection(getNameSection());
+  Name->setAlignment(1);
+
+  uint64_t NumCounters = Inc->getNumCounters()->getZExtValue();
+  LLVMContext &Ctx = M->getContext();
+  ArrayType *CounterTy = ArrayType::get(Type::getInt64Ty(Ctx), NumCounters);
+
+  // Create the counters variable.
+  auto *Counters = new GlobalVariable(*M, CounterTy, false, Name->getLinkage(),
+                                      Constant::getNullValue(CounterTy),
+                                      getVarName(Inc, "counters"));
+  Counters->setVisibility(Name->getVisibility());
+  Counters->setSection(getCountersSection());
+  Counters->setAlignment(8);
+
+  RegionCounters[Inc->getName()] = Counters;
+
+  // Create data variable.
+  auto *NameArrayTy = Name->getType()->getPointerElementType();
+  auto *Int32Ty = Type::getInt32Ty(Ctx);
+  auto *Int64Ty = Type::getInt64Ty(Ctx);
+  auto *Int8PtrTy = Type::getInt8PtrTy(Ctx);
+  auto *Int64PtrTy = Type::getInt64PtrTy(Ctx);
+
+  Type *DataTypes[] = {Int32Ty, Int32Ty, Int64Ty, Int8PtrTy, Int64PtrTy};
+  auto *DataTy = StructType::get(Ctx, makeArrayRef(DataTypes));
+  Constant *DataVals[] = {
+      ConstantInt::get(Int32Ty, NameArrayTy->getArrayNumElements()),
+      ConstantInt::get(Int32Ty, NumCounters),
+      ConstantInt::get(Int64Ty, Inc->getHash()->getZExtValue()),
+      ConstantExpr::getBitCast(Name, Int8PtrTy),
+      ConstantExpr::getBitCast(Counters, Int64PtrTy)};
+  auto *Data = new GlobalVariable(*M, DataTy, true, Name->getLinkage(),
+                                  ConstantStruct::get(DataTy, DataVals),
+                                  getVarName(Inc, "data"));
+  Data->setVisibility(Name->getVisibility());
+  Data->setSection(getDataSection());
+  Data->setAlignment(8);
+
+  // Mark the data variable as used so that it isn't stripped out.
+  UsedVars.push_back(Data);
+
+  return Counters;
+}
+
+void InstrProfiling::emitRegistration() {
+  // Don't do this for Darwin.  compiler-rt uses linker magic.
+  if (Triple(M->getTargetTriple()).isOSDarwin())
+    return;
+
+  // Construct the function.
+  auto *VoidTy = Type::getVoidTy(M->getContext());
+  auto *VoidPtrTy = Type::getInt8PtrTy(M->getContext());
+  auto *RegisterFTy = FunctionType::get(VoidTy, false);
+  auto *RegisterF = Function::Create(RegisterFTy, GlobalValue::InternalLinkage,
+                                     "__llvm_profile_register_functions", M);
+  RegisterF->setUnnamedAddr(true);
+  if (Options.NoRedZone)
+    RegisterF->addFnAttr(Attribute::NoRedZone);
+
+  auto *RuntimeRegisterTy = llvm::FunctionType::get(VoidTy, VoidPtrTy, false);
+  auto *RuntimeRegisterF =
+      Function::Create(RuntimeRegisterTy, GlobalVariable::ExternalLinkage,
+                       "__llvm_profile_register_function", M);
+
+  IRBuilder<> IRB(BasicBlock::Create(M->getContext(), "", RegisterF));
+  for (Value *Data : UsedVars)
+    IRB.CreateCall(RuntimeRegisterF, IRB.CreateBitCast(Data, VoidPtrTy));
+  IRB.CreateRetVoid();
+}
+
+void InstrProfiling::emitRuntimeHook() {
+  const char *const RuntimeVarName = "__llvm_profile_runtime";
+  const char *const RuntimeUserName = "__llvm_profile_runtime_user";
+
+  // If the module's provided its own runtime, we don't need to do anything.
+  if (M->getGlobalVariable(RuntimeVarName))
+    return;
+
+  // Declare an external variable that will pull in the runtime initialization.
+  auto *Int32Ty = Type::getInt32Ty(M->getContext());
+  auto *Var =
+      new GlobalVariable(*M, Int32Ty, false, GlobalValue::ExternalLinkage,
+                         nullptr, RuntimeVarName);
+
+  // Make a function that uses it.
+  auto *User =
+      Function::Create(FunctionType::get(Int32Ty, false),
+                       GlobalValue::LinkOnceODRLinkage, RuntimeUserName, M);
+  User->addFnAttr(Attribute::NoInline);
+  if (Options.NoRedZone)
+    User->addFnAttr(Attribute::NoRedZone);
+
+  IRBuilder<> IRB(BasicBlock::Create(M->getContext(), "", User));
+  auto *Load = IRB.CreateLoad(Var);
+  IRB.CreateRet(Load);
+
+  // Mark the user variable as used so that it isn't stripped out.
+  UsedVars.push_back(User);
+}
+
+void InstrProfiling::emitUses() {
+  if (UsedVars.empty())
+    return;
+
+  GlobalVariable *LLVMUsed = M->getGlobalVariable("llvm.used");
+  std::vector<Constant*> MergedVars;
+  if (LLVMUsed) {
+    // Collect the existing members of llvm.used.
+    ConstantArray *Inits = cast<ConstantArray>(LLVMUsed->getInitializer());
+    for (unsigned I = 0, E = Inits->getNumOperands(); I != E; ++I)
+      MergedVars.push_back(Inits->getOperand(I));
+    LLVMUsed->eraseFromParent();
+  }
+
+  Type *i8PTy = Type::getInt8PtrTy(M->getContext());
+  // Add uses for our data.
+  for (auto *Value : UsedVars)
+    MergedVars.push_back(
+        ConstantExpr::getBitCast(cast<llvm::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->setSection("llvm.metadata");
+}
+
+void InstrProfiling::emitInitialization() {
+  Constant *RegisterF = M->getFunction("__llvm_profile_register_functions");
+  if (!RegisterF)
+    return;
+
+  // Create the initialization function.
+  auto *VoidTy = Type::getVoidTy(M->getContext());
+  auto *F =
+      Function::Create(FunctionType::get(VoidTy, false),
+                       GlobalValue::InternalLinkage, "__llvm_profile_init", M);
+  F->setUnnamedAddr(true);
+  F->addFnAttr(Attribute::NoInline);
+  if (Options.NoRedZone)
+    F->addFnAttr(Attribute::NoRedZone);
+
+  // Add the basic block and the necessary calls.
+  IRBuilder<> IRB(BasicBlock::Create(M->getContext(), "", F));
+  IRB.CreateCall(RegisterF);
+  IRB.CreateRetVoid();
+
+  appendToGlobalCtors(*M, F, 0);
+}
index 8e9536715725c71c7c634cf9f6f266f8a878ced9..a91fc0ec2a489d4a08abb4f155ca7ad43b835a4a 100644 (file)
@@ -25,6 +25,7 @@ void llvm::initializeInstrumentation(PassRegistry &Registry) {
   initializeAddressSanitizerModulePass(Registry);
   initializeBoundsCheckingPass(Registry);
   initializeGCOVProfilerPass(Registry);
+  initializeInstrProfilingPass(Registry);
   initializeMemorySanitizerPass(Registry);
   initializeThreadSanitizerPass(Registry);
   initializeSanitizerCoverageModulePass(Registry);
diff --git a/test/Instrumentation/InstrProfiling/no-counters.ll b/test/Instrumentation/InstrProfiling/no-counters.ll
new file mode 100644 (file)
index 0000000..0716b0d
--- /dev/null
@@ -0,0 +1,10 @@
+;; No instrumentation should be emitted if there are no counter increments.
+
+; RUN: opt < %s -instrprof -S | FileCheck %s
+; CHECK-NOT: @__llvm_profile_counters
+; CHECK-NOT: @__llvm_profile_data
+; CHECK-NOT: @__llvm_profile_runtime
+
+define void @foo() {
+  ret void
+}
diff --git a/test/Instrumentation/InstrProfiling/noruntime.ll b/test/Instrumentation/InstrProfiling/noruntime.ll
new file mode 100644 (file)
index 0000000..e69445d
--- /dev/null
@@ -0,0 +1,16 @@
+;; Check that we don't emit the runtime hooks if the user provided them.
+
+; RUN: opt < %s -instrprof -S | FileCheck %s
+; CHECK-NOT: define {{.*}} @__llvm_profile_runtime_user()
+; CHECK-NOT: load i32* @__llvm_profile_runtime
+
+@__llvm_profile_runtime = global i32 0, align 4
+
+@__llvm_profile_name_foo = hidden constant [3 x i8] c"foo"
+
+define void @foo() {
+  call void @llvm.instrprof.increment(i8* getelementptr inbounds ([3 x i8]* @__llvm_profile_name_foo, i32 0, i32 0), i64 0, i32 1, i32 0)
+  ret void
+}
+
+declare void @llvm.instrprof.increment(i8*, i64, i32, i32)
diff --git a/test/Instrumentation/InstrProfiling/platform.ll b/test/Instrumentation/InstrProfiling/platform.ll
new file mode 100644 (file)
index 0000000..e032768
--- /dev/null
@@ -0,0 +1,29 @@
+;; Checks for platform specific section names and initialization code.
+
+; RUN: opt < %s -mtriple=x86_64-apple-macosx10.10.0 -instrprof -S | FileCheck %s -check-prefix=MACHO
+; RUN: opt < %s -mtriple=x86_64-unknown-linux -instrprof -S | FileCheck %s -check-prefix=ELF
+
+@__llvm_profile_name_foo = hidden constant [3 x i8] c"foo"
+; MACHO: @__llvm_profile_name_foo = hidden constant [3 x i8] c"foo", section "__DATA,__llvm_prf_names", align 1
+; ELF: @__llvm_profile_name_foo = hidden constant [3 x i8] c"foo", section "__llvm_prf_names", align 1
+
+; MACHO: @__llvm_profile_counters_foo = hidden global [1 x i64] zeroinitializer, section "__DATA,__llvm_prf_cnts", align 8
+; ELF: @__llvm_profile_counters_foo = hidden global [1 x i64] zeroinitializer, section "__llvm_prf_cnts", align 8
+
+; MACHO: @__llvm_profile_data_foo = hidden constant {{.*}}, section "__DATA,__llvm_prf_data", align 8
+; ELF: @__llvm_profile_data_foo = hidden constant {{.*}}, section "__llvm_prf_data", align 8
+define void @foo() {
+  call void @llvm.instrprof.increment(i8* getelementptr inbounds ([3 x i8]* @__llvm_profile_name_foo, i32 0, i32 0), i64 0, i32 1, i32 0)
+  ret void
+}
+
+declare void @llvm.instrprof.increment(i8*, i64, i32, i32)
+
+;; Emit registration functions for platforms that don't find the
+;; symbols by their sections.
+
+; MACHO-NOT: define internal void @__llvm_profile_register_functions
+; ELF: define internal void @__llvm_profile_register_functions
+
+; MACHO-NOT: define internal void @__llvm_profile_init
+; ELF: define internal void @__llvm_profile_init
diff --git a/test/Instrumentation/InstrProfiling/profiling.ll b/test/Instrumentation/InstrProfiling/profiling.ll
new file mode 100644 (file)
index 0000000..246bf6b
--- /dev/null
@@ -0,0 +1,38 @@
+; RUN: opt < %s -instrprof -S | FileCheck %s
+
+target triple = "x86_64-apple-macosx10.10.0"
+
+@__llvm_profile_name_foo = hidden constant [3 x i8] c"foo"
+; CHECK: @__llvm_profile_name_foo = hidden constant [3 x i8] c"foo", section "__DATA,__llvm_prf_names", align 1
+@__llvm_profile_name_bar = hidden constant [4 x i8] c"bar\00"
+; CHECK: @__llvm_profile_name_bar = hidden constant [4 x i8] c"bar\00", section "__DATA,__llvm_prf_names", align 1
+@baz_prof_name = hidden constant [3 x i8] c"baz"
+; CHECK: @baz_prof_name = hidden constant [3 x i8] c"baz", section "__DATA,__llvm_prf_names", align 1
+
+; CHECK: @__llvm_profile_counters_foo = hidden global [1 x i64] zeroinitializer, section "__DATA,__llvm_prf_cnts", align 8
+; CHECK: @__llvm_profile_data_foo = hidden constant {{.*}}, section "__DATA,__llvm_prf_data", align 8
+define void @foo() {
+  call void @llvm.instrprof.increment(i8* getelementptr inbounds ([3 x i8]* @__llvm_profile_name_foo, i32 0, i32 0), i64 0, i32 1, i32 0)
+  ret void
+}
+
+; CHECK: @__llvm_profile_counters_bar = hidden global [1 x i64] zeroinitializer, section "__DATA,__llvm_prf_cnts", align 8
+; CHECK: @__llvm_profile_data_bar = hidden constant {{.*}}, section "__DATA,__llvm_prf_data", align 8
+define void @bar() {
+  call void @llvm.instrprof.increment(i8* getelementptr inbounds ([4 x i8]* @__llvm_profile_name_bar, i32 0, i32 0), i64 0, i32 1, i32 0)
+  ret void
+}
+
+; CHECK: @__llvm_profile_counters_baz = hidden global [3 x i64] zeroinitializer, section "__DATA,__llvm_prf_cnts", align 8
+; CHECK: @__llvm_profile_data_baz = hidden constant {{.*}}, section "__DATA,__llvm_prf_data", align 8
+define void @baz() {
+  call void @llvm.instrprof.increment(i8* getelementptr inbounds ([3 x i8]* @baz_prof_name, i32 0, i32 0), i64 0, i32 3, i32 0)
+  call void @llvm.instrprof.increment(i8* getelementptr inbounds ([3 x i8]* @baz_prof_name, i32 0, i32 0), i64 0, i32 3, i32 1)
+  call void @llvm.instrprof.increment(i8* getelementptr inbounds ([3 x i8]* @baz_prof_name, i32 0, i32 0), i64 0, i32 3, i32 2)
+  ret void
+}
+
+declare void @llvm.instrprof.increment(i8*, i64, i32, i32)
+
+; CHECK: @__llvm_profile_runtime = external global i32
+; CHECK: @llvm.used = appending global {{.*}} @__llvm_profile_data_foo {{.*}} @__llvm_profile_data_bar {{.*}} @__llvm_profile_data_baz {{.*}} section "llvm.metadata"