[NewPM][CodeGen] Introduce machine pass and machine pass manager

Yuanfang Chen · Yuanfang Chen · commit 911565d1085d · 2020-08-07T11:00:31.000-07:00
machine pass could define four methods: - `PreservedAnalyses run(MachineFunction &, MachineFunctionAnalysisManager &)` - `Error doInitialization(Module &, MachineFunctionAnalysisManager &)` - `Error doFinalization(Module &, MachineFunctionAnalysisManager &)` - `Error run(Module &, MachineFunctionAnalysisManager &)` machine pass manger: - MachineFunctionAnalysisManager: Basically an AnalysisManager<MachineFunction> augmented with the ability to register and query IR analyses - MachineFunctionPassManager: support only two methods, `addPass` and `run` Reviewed By: arsenm, asbirlea, aeubanks Differential Revision: https://reviews.llvm.org/D67687
diff --git a/llvm/include/llvm/CodeGen/MachinePassManager.h b/llvm/include/llvm/CodeGen/MachinePassManager.h
@@ -0,0 +1,252 @@
+//===- PassManager.h --- Pass management for CodeGen ------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This header defines the pass manager interface for codegen. The codegen
+// pipeline consists of only machine function passes. There is no container
+// relationship between IR module/function and machine function in terms of pass
+// manager organization. So there is no need for adaptor classes (for example
+// ModuleToMachineFunctionAdaptor). Since invalidation could only happen among
+// machine function passes, there is no proxy classes to handle cross-IR-unit
+// invalidation. IR analysis results are provided for machine function passes by
+// their respective analysis managers such as ModuleAnalysisManager and
+// FunctionAnalysisManager.
+//
+// TODO: Add MachineFunctionProperties support.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CODEGEN_MACHINEPASSMANAGER_H
+#define LLVM_CODEGEN_MACHINEPASSMANAGER_H
+
+#include "llvm/ADT/FunctionExtras.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/type_traits.h"
+
+namespace llvm {
+class Module;
+
+extern template class AnalysisManager<MachineFunction>;
+
+/// An AnalysisManager<MachineFunction> that also exposes IR analysis results.
+class MachineFunctionAnalysisManager : public AnalysisManager<MachineFunction> {
+public:
+  using Base = AnalysisManager<MachineFunction>;
+
+  MachineFunctionAnalysisManager() : Base(false), FAM(nullptr), MAM(nullptr) {}
+  MachineFunctionAnalysisManager(FunctionAnalysisManager &FAM,
+                                 ModuleAnalysisManager &MAM,
+                                 bool DebugLogging = false)
+      : Base(DebugLogging), FAM(&FAM), MAM(&MAM) {}
+  MachineFunctionAnalysisManager(MachineFunctionAnalysisManager &&) = default;
+  MachineFunctionAnalysisManager &
+  operator=(MachineFunctionAnalysisManager &&) = default;
+
+  /// Get the result of an analysis pass for a Function.
+  ///
+  /// Runs the analysis if a cached result is not available.
+  template <typename PassT> typename PassT::Result &getResult(Function &F) {
+    return FAM->getResult<PassT>(F);
+  }
+
+  /// Get the cached result of an analysis pass for a Function.
+  ///
+  /// This method never runs the analysis.
+  ///
+  /// \returns null if there is no cached result.
+  template <typename PassT>
+  typename PassT::Result *getCachedResult(Function &F) {
+    return FAM->getCachedResult<PassT>(F);
+  }
+
+  /// Get the result of an analysis pass for a Module.
+  ///
+  /// Runs the analysis if a cached result is not available.
+  template <typename PassT> typename PassT::Result &getResult(Module &M) {
+    return MAM->getResult<PassT>(M);
+  }
+
+  /// Get the cached result of an analysis pass for a Module.
+  ///
+  /// This method never runs the analysis.
+  ///
+  /// \returns null if there is no cached result.
+  template <typename PassT> typename PassT::Result *getCachedResult(Module &M) {
+    return MAM->getCachedResult<PassT>(M);
+  }
+
+  /// Get the result of an analysis pass for a MachineFunction.
+  ///
+  /// Runs the analysis if a cached result is not available.
+  using Base::getResult;
+
+  /// Get the cached result of an analysis pass for a MachineFunction.
+  ///
+  /// This method never runs the analysis.
+  ///
+  /// \returns null if there is no cached result.
+  using Base::getCachedResult;
+
+  // FIXME: Add LoopAnalysisManager or CGSCCAnalysisManager if needed.
+  FunctionAnalysisManager *FAM;
+  ModuleAnalysisManager *MAM;
+};
+
+extern template class PassManager<MachineFunction>;
+
+/// MachineFunctionPassManager adds/removes below features to/from the base
+/// PassManager template instantiation.
+///
+/// - Support passes that implement doInitialization/doFinalization. This is for
+///   machine function passes to work on module level constructs. One such pass
+///   is AsmPrinter.
+///
+/// - Support machine module pass which runs over the module (for example,
+///   MachineOutliner). A machine module pass needs to define the method:
+///
+///   ```Error run(Module &, MachineFunctionAnalysisManager &)```
+///
+///   FIXME: machine module passes still need to define the usual machine
+///          function pass interface, namely,
+///          `PreservedAnalyses run(MachineFunction &,
+///                                 MachineFunctionAnalysisManager &)`
+///          But this interface wouldn't be executed. It is just a placeholder
+///          to satisfy the pass manager type-erased inteface. This
+///          special-casing of machine module pass is due to its limited use
+///          cases and the unnecessary complexity it may bring to the machine
+///          pass manager.
+///
+/// - The base class `run` method is replaced by an alternative `run` method.
+///   See details below.
+///
+/// - Support codegening in the SCC order. Users include interprocedural
+///   register allocation (IPRA).
+class MachineFunctionPassManager
+    : public PassManager<MachineFunction, MachineFunctionAnalysisManager> {
+  using Base = PassManager<MachineFunction, MachineFunctionAnalysisManager>;
+
+public:
+  MachineFunctionPassManager(bool DebugLogging = false,
+                             bool RequireCodeGenSCCOrder = false)
+      : Base(DebugLogging), RequireCodeGenSCCOrder(RequireCodeGenSCCOrder) {}
+  MachineFunctionPassManager(MachineFunctionPassManager &&) = default;
+  MachineFunctionPassManager &
+  operator=(MachineFunctionPassManager &&) = default;
+
+  /// Run machine passes for a Module.
+  ///
+  /// The intended use is to start the codegen pipeline for a Module. The base
+  /// class's `run` method is deliberately hidden by this due to the observation
+  /// that we don't yet have the use cases of compositing two instances of
+  /// machine pass managers, or compositing machine pass managers with other
+  /// types of pass managers.
+  Error run(Module &M, MachineFunctionAnalysisManager &MFAM);
+
+  template <typename PassT> void addPass(PassT &&Pass) {
+    Base::addPass(std::forward<PassT>(Pass));
+    PassConceptT *P = Passes.back().get();
+    addDoInitialization<PassT>(P);
+    addDoFinalization<PassT>(P);
+
+    // Add machine module pass.
+    addRunOnModule<PassT>(P);
+  }
+
+private:
+  template <typename PassT>
+  using has_init_t = decltype(std::declval<PassT &>().doInitialization(
+      std::declval<Module &>(),
+      std::declval<MachineFunctionAnalysisManager &>()));
+
+  template <typename PassT>
+  std::enable_if_t<!is_detected<has_init_t, PassT>::value>
+  addDoInitialization(PassConceptT *Pass) {}
+
+  template <typename PassT>
+  std::enable_if_t<is_detected<has_init_t, PassT>::value>
+  addDoInitialization(PassConceptT *Pass) {
+    using PassModelT =
+        detail::PassModel<MachineFunction, PassT, PreservedAnalyses,
+                          MachineFunctionAnalysisManager>;
+    auto *P = static_cast<PassModelT *>(Pass);
+    InitializationFuncs.emplace_back(
+        [=](Module &M, MachineFunctionAnalysisManager &MFAM) {
+          return P->Pass.doInitialization(M, MFAM);
+        });
+  }
+
+  template <typename PassT>
+  using has_fini_t = decltype(std::declval<PassT &>().doFinalization(
+      std::declval<Module &>(),
+      std::declval<MachineFunctionAnalysisManager &>()));
+
+  template <typename PassT>
+  std::enable_if_t<!is_detected<has_fini_t, PassT>::value>
+  addDoFinalization(PassConceptT *Pass) {}
+
+  template <typename PassT>
+  std::enable_if_t<is_detected<has_fini_t, PassT>::value>
+  addDoFinalization(PassConceptT *Pass) {
+    using PassModelT =
+        detail::PassModel<MachineFunction, PassT, PreservedAnalyses,
+                          MachineFunctionAnalysisManager>;
+    auto *P = static_cast<PassModelT *>(Pass);
+    FinalizationFuncs.emplace_back(
+        [=](Module &M, MachineFunctionAnalysisManager &MFAM) {
+          return P->Pass.doFinalization(M, MFAM);
+        });
+  }
+
+  template <typename PassT>
+  using is_machine_module_pass_t = decltype(std::declval<PassT &>().run(
+      std::declval<Module &>(),
+      std::declval<MachineFunctionAnalysisManager &>()));
+
+  template <typename PassT>
+  using is_machine_function_pass_t = decltype(std::declval<PassT &>().run(
+      std::declval<MachineFunction &>(),
+      std::declval<MachineFunctionAnalysisManager &>()));
+
+  template <typename PassT>
+  std::enable_if_t<!is_detected<is_machine_module_pass_t, PassT>::value>
+  addRunOnModule(PassConceptT *Pass) {}
+
+  template <typename PassT>
+  std::enable_if_t<is_detected<is_machine_module_pass_t, PassT>::value>
+  addRunOnModule(PassConceptT *Pass) {
+    static_assert(is_detected<is_machine_function_pass_t, PassT>::value,
+                  "machine module pass needs to define machine function pass "
+                  "api. sorry.");
+
+    using PassModelT =
+        detail::PassModel<MachineFunction, PassT, PreservedAnalyses,
+                          MachineFunctionAnalysisManager>;
+    auto *P = static_cast<PassModelT *>(Pass);
+    MachineModulePasses.emplace(
+        Passes.size() - 1,
+        [=](Module &M, MachineFunctionAnalysisManager &MFAM) {
+          return P->Pass.run(M, MFAM);
+        });
+  }
+
+  using FuncTy = Error(Module &, MachineFunctionAnalysisManager &);
+  SmallVector<llvm::unique_function<FuncTy>, 4> InitializationFuncs;
+  SmallVector<llvm::unique_function<FuncTy>, 4> FinalizationFuncs;
+
+  using PassIndex = decltype(Passes)::size_type;
+  std::map<PassIndex, llvm::unique_function<FuncTy>> MachineModulePasses;
+
+  // Run codegen in the SCC order.
+  bool RequireCodeGenSCCOrder;
+};
+
+} // end namespace llvm
+
+#endif // LLVM_CODEGEN_MACHINEPASSMANAGER_H
diff --git a/llvm/include/llvm/IR/PassManager.h b/llvm/include/llvm/IR/PassManager.h
@@ -558,7 +558,7 @@ class PassManager : public PassInfoMixin<
 
   static bool isRequired() { return true; }
 
-private:
+protected:
   using PassConceptT =
       detail::PassConcept<IRUnitT, AnalysisManagerT, ExtraArgTs...>;
 
diff --git a/llvm/lib/CodeGen/CMakeLists.txt b/llvm/lib/CodeGen/CMakeLists.txt
@@ -92,6 +92,7 @@ add_llvm_component_library(LLVMCodeGen
   MachineOperand.cpp
   MachineOptimizationRemarkEmitter.cpp
   MachineOutliner.cpp
+  MachinePassManager.cpp
   MachinePipeliner.cpp
   MachinePostDominators.cpp
   MachineRegionInfo.cpp
diff --git a/llvm/lib/CodeGen/LLVMBuild.txt b/llvm/lib/CodeGen/LLVMBuild.txt
@@ -21,4 +21,4 @@ subdirectories = AsmPrinter SelectionDAG MIRParser GlobalISel
 type = Library
 name = CodeGen
 parent = Libraries
-required_libraries = Analysis BitReader BitWriter Core MC ProfileData Scalar Support Target TransformUtils
+required_libraries = Analysis BitReader BitWriter Core MC Passes ProfileData Scalar Support Target TransformUtils
diff --git a/llvm/lib/CodeGen/MachinePassManager.cpp b/llvm/lib/CodeGen/MachinePassManager.cpp
@@ -0,0 +1,103 @@
+//===---------- MachinePassManager.cpp ------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the pass management machinery for machine functions.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/MachinePassManager.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/IR/PassManagerImpl.h"
+
+using namespace llvm;
+
+namespace llvm {
+template class AllAnalysesOn<MachineFunction>;
+template class AnalysisManager<MachineFunction>;
+template class PassManager<MachineFunction>;
+
+Error MachineFunctionPassManager::run(Module &M,
+                                      MachineFunctionAnalysisManager &MFAM) {
+  // MachineModuleAnalysis is a module analysis pass that is never invalidated
+  // because we don't run any module pass in codegen pipeline. This is very
+  // important because the codegen state is stored in MMI which is the analysis
+  // result of MachineModuleAnalysis. MMI should not be recomputed.
+  auto &MMI = MFAM.getResult<MachineModuleAnalysis>(M);
+
+  assert(!RequireCodeGenSCCOrder && "not implemented");
+
+  if (DebugLogging) {
+    dbgs() << "Starting " << getTypeName<MachineFunction>()
+           << " pass manager run.\n";
+  }
+
+  for (auto &F : InitializationFuncs) {
+    if (auto Err = F(M, MFAM))
+      return Err;
+  }
+
+  unsigned Idx = 0;
+  size_t Size = Passes.size();
+  do {
+    // Run machine module passes
+    for (; MachineModulePasses.count(Idx) && Idx != Size; ++Idx) {
+      if (DebugLogging)
+        dbgs() << "Running pass: " << Passes[Idx]->name() << " on "
+               << M.getName() << '\n';
+      if (auto Err = MachineModulePasses.at(Idx)(M, MFAM))
+        return Err;
+    }
+
+    // Finish running all passes.
+    if (Idx == Size)
+      break;
+
+    // Run machine function passes
+
+    // Get index range of machine function passes.
+    unsigned Begin = Idx;
+    for (; !MachineModulePasses.count(Idx) && Idx != Size; ++Idx)
+      ;
+
+    for (Function &F : M) {
+      // Do not codegen any 'available_externally' functions at all, they have
+      // definitions outside the translation unit.
+      if (F.hasAvailableExternallyLinkage())
+        continue;
+
+      MachineFunction &MF = MMI.getOrCreateMachineFunction(F);
+      PassInstrumentation PI = MFAM.getResult<PassInstrumentationAnalysis>(MF);
+
+      for (unsigned I = Begin, E = Idx; I != E; ++I) {
+        auto *P = Passes[I].get();
+
+        if (!PI.runBeforePass<MachineFunction>(*P, MF))
+          continue;
+
+        // TODO: EmitSizeRemarks
+        PreservedAnalyses PassPA = P->run(MF, MFAM);
+        PI.runAfterPass(*P, MF);
+        MFAM.invalidate(MF, PassPA);
+      }
+    }
+  } while (true);
+
+  for (auto &F : FinalizationFuncs) {
+    if (auto Err = F(M, MFAM))
+      return Err;
+  }
+
+  if (DebugLogging) {
+    dbgs() << "Finished " << getTypeName<MachineFunction>()
+           << " pass manager run.\n";
+  }
+
+  return Error::success();
+}
+
+} // namespace llvm
diff --git a/llvm/unittests/CodeGen/CMakeLists.txt b/llvm/unittests/CodeGen/CMakeLists.txt
@@ -7,6 +7,7 @@ set(LLVM_LINK_COMPONENTS
   Core
   MC
   MIRParser
+  Passes
   SelectionDAG
   Support
   Target
@@ -20,6 +21,7 @@ add_llvm_unittest(CodeGenTests
   MachineInstrBundleIteratorTest.cpp
   MachineInstrTest.cpp
   MachineOperandTest.cpp
+  PassManagerTest.cpp
   ScalableVectorMVTsTest.cpp
   TypeTraitsTest.cpp
   TargetOptionsTest.cpp
diff --git a/llvm/unittests/CodeGen/PassManagerTest.cpp b/llvm/unittests/CodeGen/PassManagerTest.cpp
