[PGO] Passmanagerbuilder change that enable IR level PGO instrumentation

This patch includes the passmanagerbuilder change that enables IR level PGO instrumentation. It adds two passmanagerbuilder options: -profile-generate=<profile_filename> and -profile-use=<profile_filename>. The new options are primarily for debug purpose.

Reviewers: davidxl, silvas

Differential Revision: http://reviews.llvm.org/D15828

llvm-svn: 258420

llvm/include/llvm/Transforms/IPO/PassManagerBuilder.h

@@ -133,6 +133,11 @@ class PassManagerBuilder {
   bool MergeFunctions;
   bool PrepareForLTO;
 
+  /// Profile data file name that the instrumentation will be written to.
+  std::string PGOInstrGen;
+  /// Path of the profile data file.
+  std::string PGOInstrUse;
+
 private:
   /// ExtensionList - This is list of all of the extensions that are registered.
   std::vector<std::pair<ExtensionPointTy, ExtensionFn> > Extensions;
@@ -152,6 +157,7 @@ class PassManagerBuilder {
   void addInitialAliasAnalysisPasses(legacy::PassManagerBase &PM) const;
   void addLTOOptimizationPasses(legacy::PassManagerBase &PM);
   void addLateLTOOptimizationPasses(legacy::PassManagerBase &PM);
+  void addPGOInstrPasses(legacy::PassManagerBase &MPM);
 
 public:
   /// populateFunctionPassManager - This fills in the function pass manager,

llvm/lib/Transforms/IPO/LLVMBuild.txt

@@ -20,4 +20,4 @@ type = Library
 name = IPO
 parent = Transforms
 library_name = ipo
-required_libraries = Analysis Core InstCombine IRReader Linker Object ProfileData Scalar Support TransformUtils Vectorize
+required_libraries = Analysis Core InstCombine IRReader Linker Object ProfileData Scalar Support TransformUtils Vectorize Instrumentation

llvm/lib/Transforms/IPO/PassManagerBuilder.cpp

@@ -34,6 +34,7 @@
 #include "llvm/Transforms/IPO/InferFunctionAttrs.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Vectorize.h"
+#include "llvm/Transforms/Instrumentation.h"
 
 using namespace llvm;
 
@@ -105,6 +106,16 @@ static cl::opt<bool> EnableLoopLoadElim(
     "enable-loop-load-elim", cl::init(false), cl::Hidden,
     cl::desc("Enable the new, experimental LoopLoadElimination Pass"));
 
+static cl::opt<std::string> RunPGOInstrGen(
+    "profile-generate", cl::init(""), cl::Hidden,
+    cl::desc("Enable generation phase of PGO instrumentation and specify the "
+             "path of profile data file"));
+
+static cl::opt<std::string> RunPGOInstrUse(
+    "profile-use", cl::init(""), cl::Hidden, cl::value_desc("filename"),
+    cl::desc("Enable use phase of PGO instrumentation and specify the path "
+             "of profile data file"));
+
 PassManagerBuilder::PassManagerBuilder() {
     OptLevel = 2;
     SizeLevel = 0;
@@ -123,6 +134,8 @@ PassManagerBuilder::PassManagerBuilder() {
     VerifyOutput = false;
     MergeFunctions = false;
     PrepareForLTO = false;
+    PGOInstrGen = RunPGOInstrGen;
+    PGOInstrUse = RunPGOInstrUse;
 }
 
 PassManagerBuilder::~PassManagerBuilder() {
@@ -186,6 +199,19 @@ void PassManagerBuilder::populateFunctionPassManager(
   FPM.add(createLowerExpectIntrinsicPass());
 }
 
+// Do PGO instrumentation generation or use pass as the option specified.
+void PassManagerBuilder::addPGOInstrPasses(legacy::PassManagerBase &MPM) {
+  if (!PGOInstrGen.empty()) {
+    MPM.add(createPGOInstrumentationGenPass());
+    // Add the profile lowering pass.
+    InstrProfOptions Options;
+    Options.InstrProfileOutput = PGOInstrGen;
+    MPM.add(createInstrProfilingPass(Options));
+  }
+  if (!PGOInstrUse.empty())
+    MPM.add(createPGOInstrumentationUsePass(PGOInstrUse));
+}
+
 void PassManagerBuilder::populateModulePassManager(
     legacy::PassManagerBase &MPM) {
   // Allow forcing function attributes as a debugging and tuning aid.
@@ -194,6 +220,7 @@ void PassManagerBuilder::populateModulePassManager(
   // If all optimizations are disabled, just run the always-inline pass and,
   // if enabled, the function merging pass.
   if (OptLevel == 0) {
+    addPGOInstrPasses(MPM);
     if (Inliner) {
       MPM.add(Inliner);
       Inliner = nullptr;
@@ -237,6 +264,8 @@ void PassManagerBuilder::populateModulePassManager(
     MPM.add(createCFGSimplificationPass());   // Clean up after IPCP & DAE
   }
 
+  addPGOInstrPasses(MPM);
+
   if (EnableNonLTOGlobalsModRef)
     // We add a module alias analysis pass here. In part due to bugs in the
     // analysis infrastructure this "works" in that the analysis stays alive