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/CodeGen/MachineFunctionPass.h"
  18 #include "llvm/Support/BlockFrequency.h"
  19 #include <climits>
  20
  21 namespace llvm {
  22
  23 class MachineBasicBlock;
  24 class MachineBranchProbabilityInfo;
  25 template <class BlockT, class FunctionT, class BranchProbInfoT>
  26 class BlockFrequencyInfoImpl;
  27
  28 /// MachineBlockFrequencyInfo pass uses BlockFrequencyInfoImpl implementation
  29 /// to estimate machine basic block frequencies.
  30 class MachineBlockFrequencyInfo : public MachineFunctionPass {
  31   typedef BlockFrequencyInfoImpl<MachineBasicBlock, MachineFunction,
  32                                  MachineBranchProbabilityInfo> ImplType;
  33   std::unique_ptr<ImplType> MBFI;
  34
  35 public:
  36   static char ID;
  37
  38   MachineBlockFrequencyInfo();
  39
  40   ~MachineBlockFrequencyInfo();
  41
  42   void getAnalysisUsage(AnalysisUsage &AU) const override;
  43
  44   bool runOnMachineFunction(MachineFunction &F) override;
  45
  46   void releaseMemory() override;
  47
  48   /// getblockFreq - Return block frequency. Return 0 if we don't have the
  49   /// information. Please note that initial frequency is equal to 1024. It means
  50   /// that we should not rely on the value itself, but only on the comparison to
  51   /// the other block frequencies. We do this to avoid using of floating points.
  52   ///
  53   BlockFrequency getBlockFreq(const MachineBasicBlock *MBB) const;
  54
  55   const MachineFunction *getFunction() const;
  56   void view() const;
  57
  58   // Print the block frequency Freq to OS using the current functions entry
  59   // frequency to convert freq into a relative decimal form.
  60   raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const;
  61
  62   // Convenience method that attempts to look up the frequency associated with
  63   // BB and print it to OS.
  64   raw_ostream &printBlockFreq(raw_ostream &OS,
  65                               const MachineBasicBlock *MBB) const;
  66
  67   uint64_t getEntryFreq() const;
  68
  69 };
  70
  71 }
  72
  73 #endif