src/llvm/include/llvm/Analysis/RegionPass.h

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