contrib/llvm/include/llvm/CodeGen/MachineBlockFrequencyInfo.h

   1 //===- MachineBlockFrequencyInfo.h - MBB Frequency Analysis -----*- 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 // Loops should be simplified before this analysis.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H
  15 #define LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H
  16
  17 #include "llvm/ADT/Optional.h"
  18 #include "llvm/CodeGen/MachineFunctionPass.h"
  19 #include "llvm/Support/BlockFrequency.h"
  20 #include <cstdint>
  21 #include <memory>
  22
  23 namespace llvm {
  24
  25 template <class BlockT> class BlockFrequencyInfoImpl;
  26 class MachineBasicBlock;
  27 class MachineBranchProbabilityInfo;
  28 class MachineFunction;
  29 class MachineLoopInfo;
  30 class raw_ostream;
  31
  32 /// MachineBlockFrequencyInfo pass uses BlockFrequencyInfoImpl implementation
  33 /// to estimate machine basic block frequencies.
  34 class MachineBlockFrequencyInfo : public MachineFunctionPass {
  35   using ImplType = BlockFrequencyInfoImpl<MachineBasicBlock>;
  36   std::unique_ptr<ImplType> MBFI;
  37
  38 public:
  39   static char ID;
  40
  41   MachineBlockFrequencyInfo();
  42   ~MachineBlockFrequencyInfo() override;
  43
  44   void getAnalysisUsage(AnalysisUsage &AU) const override;
  45
  46   bool runOnMachineFunction(MachineFunction &F) override;
  47
  48   /// calculate - compute block frequency info for the given function.
  49   void calculate(const MachineFunction &F,
  50                  const MachineBranchProbabilityInfo &MBPI,
  51                  const MachineLoopInfo &MLI);
  52
  53   void releaseMemory() override;
  54
  55   /// getblockFreq - Return block frequency. Return 0 if we don't have the
  56   /// information. Please note that initial frequency is equal to 1024. It means
  57   /// that we should not rely on the value itself, but only on the comparison to
  58   /// the other block frequencies. We do this to avoid using of floating points.
  59   ///
  60   BlockFrequency getBlockFreq(const MachineBasicBlock *MBB) const;
  61
  62   Optional<uint64_t> getBlockProfileCount(const MachineBasicBlock *MBB) const;
  63   Optional<uint64_t> getProfileCountFromFreq(uint64_t Freq) const;
  64
  65   const MachineFunction *getFunction() const;
  66   const MachineBranchProbabilityInfo *getMBPI() const;
  67   void view(const Twine &Name, bool isSimple = true) const;
  68
  69   // Print the block frequency Freq to OS using the current functions entry
  70   // frequency to convert freq into a relative decimal form.
  71   raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const;
  72
  73   // Convenience method that attempts to look up the frequency associated with
  74   // BB and print it to OS.
  75   raw_ostream &printBlockFreq(raw_ostream &OS,
  76                               const MachineBasicBlock *MBB) const;
  77
  78   uint64_t getEntryFreq() const;
  79 };
  80
  81 } // end namespace llvm
  82
  83 #endif // LLVM_CODEGEN_MACHINEBLOCKFREQUENCYINFO_H