llvm/include/llvm/Analysis/RegionPass.h

   1 //===- RegionPass.h - RegionPass class --------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file defines the RegionPass class. All region based analysis,
  10 // optimization and transformation passes are derived from RegionPass.
  11 // This class is implemented following the some ideas of the LoopPass.h class.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_ANALYSIS_REGIONPASS_H
  16 #define LLVM_ANALYSIS_REGIONPASS_H
  17
  18 #include "llvm/IR/LegacyPassManagers.h"
  19 #include "llvm/Pass.h"
  20 #include <deque>
  21
  22 namespace llvm {
  23 class Function;
  24 class RGPassManager;
  25 class Region;
  26 class RegionInfo;
  27
  28 //===----------------------------------------------------------------------===//
  29 /// A pass that runs on each Region in a function.
  30 ///
  31 /// RegionPass is managed by RGPassManager.
  32 class RegionPass : public Pass {
  33 public:
  34   explicit RegionPass(char &pid) : Pass(PT_Region, pid) {}
  35
  36   //===--------------------------------------------------------------------===//
  37   /// @name To be implemented by every RegionPass
  38   ///
  39   //@{
  40   /// Run the pass on a specific Region
  41   ///
  42   /// Accessing regions not contained in the current region is not allowed.
  43   ///
  44   /// @param R The region this pass is run on.
  45   /// @param RGM The RegionPassManager that manages this Pass.
  46   ///
  47   /// @return True if the pass modifies this Region.
  48   virtual bool runOnRegion(Region *R, RGPassManager &RGM) = 0;
  49
  50   /// Get a pass to print the LLVM IR in the region.
  51   ///
  52   /// @param O      The output stream to print the Region.
  53   /// @param Banner The banner to separate different printed passes.
  54   ///
  55   /// @return The pass to print the LLVM IR in the region.
  56   Pass *createPrinterPass(raw_ostream &O,
  57                           const std::string &Banner) const override;
  58
  59   using llvm::Pass::doInitialization;
  60   using llvm::Pass::doFinalization;
  61
  62   virtual bool doInitialization(Region *R, RGPassManager &RGM) { return false; }
  63   virtual bool doFinalization() { return false; }
  64   //@}
  65
  66   //===--------------------------------------------------------------------===//
  67   /// @name PassManager API
  68   ///
  69   //@{
  70   void preparePassManager(PMStack &PMS) override;
  71
  72   void assignPassManager(PMStack &PMS,
  73                          PassManagerType PMT = PMT_RegionPassManager) override;
  74
  75   PassManagerType getPotentialPassManagerType() const override {
  76     return PMT_RegionPassManager;
  77   }
  78   //@}
  79
  80 protected:
  81   /// Optional passes call this function to check whether the pass should be
  82   /// skipped. This is the case when optimization bisect is over the limit.
  83   bool skipRegion(Region &R) const;
  84 };
  85
  86 /// The pass manager to schedule RegionPasses.
  87 class RGPassManager : public FunctionPass, public PMDataManager {
  88   std::deque<Region*> RQ;
  89   RegionInfo *RI;
  90   Region *CurrentRegion;
  91
  92 public:
  93   static char ID;
  94   explicit RGPassManager();
  95
  96   /// Execute all of the passes scheduled for execution.
  97   ///
  98   /// @return True if any of the passes modifies the function.
  99   bool runOnFunction(Function &F) override;
 100
 101   /// Pass Manager itself does not invalidate any analysis info.
 102   /// RGPassManager needs RegionInfo.
 103   void getAnalysisUsage(AnalysisUsage &Info) const override;
 104
 105   StringRef getPassName() const override { return "Region Pass Manager"; }
 106
 107   PMDataManager *getAsPMDataManager() override { return this; }
 108   Pass *getAsPass() override { return this; }
 109
 110   /// Print passes managed by this manager.
 111   void dumpPassStructure(unsigned Offset) override;
 112
 113   /// Get passes contained by this manager.
 114   Pass *getContainedPass(unsigned N) {
 115     assert(N < PassVector.size() && "Pass number out of range!");
 116     Pass *FP = static_cast<Pass *>(PassVector[N]);
 117     return FP;
 118   }
 119
 120   PassManagerType getPassManagerType() const override {
 121     return PMT_RegionPassManager;
 122   }
 123 };
 124
 125 } // End llvm namespace
 126
 127 #endif