Hook the sample PGO machinery in the new PM

[danielcdh]

Summary

This patch hooks up SampleProfileLoaderPass with the new PM.

[davidxl]

One or more integration test (using clang driver with new PM) is probably needed.

[danielcdh]

In D34720#792993, @davidxl wrote:

One or more integration test (using clang driver with new PM) is probably needed.

The test is added in the clang side: https://reviews.llvm.org/D34721

[tejohnson]

LGTM

lib/Passes/PassBuilder.cpp

781

Looks like this line might need to be clang formatted (indention fix), but maybe it just looks funny in Phab?

[danielcdh]

lib/Passes/PassBuilder.cpp

781

This is actually the layout generated by clang-format. Yes, it indeed looks strange...

[danielcdh]

As https://reviews.llvm.org/D34728 has already landed, this patch is ready to land.

Chandler and David, let me know if you have further concerns. I will commit this patch and https://reviews.llvm.org/D34721 Friday morning if no more concerns have been raised.

Thanks,
Dehao

[davidxl]

No, I don't have other comments.

[chandlerc]

FWIW, I think this is fine to go in...

If we need more integration tests, they can be in follow-up patches?

You should (probably) be able to use the debug logging patch Tim just finished to test this I think? Anyways, very happy for those to be in follow-up commits. Let's get this in so folks can start using it. =D

include/llvm/Passes/PassBuilder.h

 class StringRef;
 class AAManager;
 class TargetMachine;
 
 /// A struct capturing PGO tunables.
 struct PGOOptions {
   std::string ProfileGenFile = "";
   std::string ProfileUseFile = "";
+  std::string SampleProfileFile = "";
   bool RunProfileGen = false;
-  bool SamplePGO = false;
 };
 
 /// \brief This class provides access to building LLVM's passes.
 ///
 /// It's members provide the baseline state available to passes during their
 /// construction. The \c PassRegistry.def file specifies how to construct all
 /// of the built-in passes, and those may reference these members during
 /// construction.

include/llvm/Transforms/SampleProfile.h

 #include "llvm/IR/PassManager.h"
 
 namespace llvm {
 
 /// The sample profiler data loader pass.
 class SampleProfileLoaderPass : public PassInfoMixin<SampleProfileLoaderPass> {
 public:
   PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
+  SampleProfileLoaderPass(std::string File = "") : ProfileFileName(File) {}
+
+private:
+  std::string ProfileFileName;
 };
 
 } // End llvm namespace
 #endif

lib/Passes/PassBuilder.cpp

PassBuilder::buildModuleSimplificationPipeline(OptimizationLevel Level,
   // optimizations.
   FunctionPassManager GlobalCleanupPM(DebugLogging);
   GlobalCleanupPM.addPass(InstCombinePass());
   GlobalCleanupPM.addPass(SimplifyCFGPass());
   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(GlobalCleanupPM)));
 
   // Add all the requested passes for PGO, if requested.
   if (PGOOpt) {
-    assert(PGOOpt->RunProfileGen || PGOOpt->SamplePGO ||
+    assert(PGOOpt->RunProfileGen || !PGOOpt->SampleProfileFile.empty() ||
            !PGOOpt->ProfileUseFile.empty());
+    if (PGOOpt->SampleProfileFile.empty())
       addPGOInstrPasses(MPM, DebugLogging, Level, PGOOpt->RunProfileGen,
                         PGOOpt->ProfileGenFile, PGOOpt->ProfileUseFile);
+    else
+      MPM.addPass(SampleProfileLoaderPass(PGOOpt->SampleProfileFile));
 
     // Indirect call promotion that promotes intra-module targes only.
-    MPM.addPass(PGOIndirectCallPromotion(false, PGOOpt && PGOOpt->SamplePGO));
+    MPM.addPass(PGOIndirectCallPromotion(
+        false, PGOOpt && !PGOOpt->SampleProfileFile.empty()));
   }
 
   // Require the GlobalsAA analysis for the module so we can query it within
   // the CGSCC pipeline.
   MPM.addPass(RequireAnalysisPass<GlobalsAA, Module>());
 
   // Require the ProfileSummaryAnalysis for the module so we can query it within
   // the inliner pass.
PassBuilder::buildThinLTODefaultPipeline(OptimizationLevel Level,
   ModulePassManager MPM(DebugLogging);
 
   // Force any function attributes we want the rest of the pipeline to observe.
   MPM.addPass(ForceFunctionAttrsPass());
 
   // During the ThinLTO backend phase we perform early indirect call promotion
   // here, before globalopt. Otherwise imported available_externally functions
   // look unreferenced and are removed.
-  MPM.addPass(PGOIndirectCallPromotion(true /* InLTO */,
-                                       PGOOpt && PGOOpt->SamplePGO &&
-                                           !PGOOpt->ProfileUseFile.empty()));
+  MPM.addPass(PGOIndirectCallPromotion(
+      true /* InLTO */, PGOOpt && !PGOOpt->SampleProfileFile.empty() &&
 
   // Add the core simplification pipeline.
   MPM.addPass(buildModuleSimplificationPipeline(Level, DebugLogging));
 
   // Now add the optimization pipeline.
   MPM.addPass(buildModuleOptimizationPipeline(Level, DebugLogging));
 
   return MPM;
ModulePassManager PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level,
   // libraries and other oracles.
   MPM.addPass(InferFunctionAttrsPass());
 
   if (Level > 1) {
     // Indirect call promotion. This should promote all the targets that are
     // left by the earlier promotion pass that promotes intra-module targets.
     // This two-step promotion is to save the compile time. For LTO, it should
     // produce the same result as if we only do promotion here.
-    MPM.addPass(PGOIndirectCallPromotion(true /* InLTO */,
-                                         PGOOpt && PGOOpt->SamplePGO));
+    MPM.addPass(PGOIndirectCallPromotion(
+        true /* InLTO */, PGOOpt && !PGOOpt->SampleProfileFile.empty()));
 
     // Propagate constants at call sites into the functions they call.  This
     // opens opportunities for globalopt (and inlining) by substituting function
     // pointers passed as arguments to direct uses of functions.
    MPM.addPass(IPSCCPPass());
   }
 
   // Now deduce any function attributes based in the current code.

lib/Transforms/IPO/SampleProfile.cpp

bool SampleProfileLoader::runOnFunction(Function &F) {
   if (Samples && !Samples->empty())
     return emitAnnotations(F);
   return false;
 }
 
 PreservedAnalyses SampleProfileLoaderPass::run(Module &M,
                                                ModuleAnalysisManager &AM) {
 
-  SampleProfileLoader SampleLoader(SampleProfileFile);
+  SampleProfileLoader SampleLoader(
+      ProfileFileName.empty() ? SampleProfileFile : ProfileFileName);
 
   SampleLoader.doInitialization(M);
 
   if (!SampleLoader.runOnModule(M))
     return PreservedAnalyses::all();
 
   return PreservedAnalyses::none();
 }