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 <climits>
  21
  22 namespace llvm {
  23
  24 class MachineBasicBlock;
  25 class MachineBranchProbabilityInfo;
  26 template <class BlockT> 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> ImplType;
  32   std::unique_ptr<ImplType> MBFI;
  33
  34 public:
  35   static char ID;
  36
  37   MachineBlockFrequencyInfo();
  38
  39   ~MachineBlockFrequencyInfo() override;
  40
  41   void getAnalysisUsage(AnalysisUsage &AU) const override;
  42
  43   bool runOnMachineFunction(MachineFunction &F) override;
  44
  45   void releaseMemory() override;
  46
  47   /// getblockFreq - Return block frequency. Return 0 if we don't have the
  48   /// information. Please note that initial frequency is equal to 1024. It means
  49   /// that we should not rely on the value itself, but only on the comparison to
  50   /// the other block frequencies. We do this to avoid using of floating points.
  51   ///
  52   BlockFrequency getBlockFreq(const MachineBasicBlock *MBB) const;
  53
  54   Optional<uint64_t> getBlockProfileCount(const MachineBasicBlock *MBB) const;
  55
  56   const MachineFunction *getFunction() const;
  57   const MachineBranchProbabilityInfo *getMBPI() const;
  58   void view() const;
  59
  60   // Print the block frequency Freq to OS using the current functions entry
  61   // frequency to convert freq into a relative decimal form.
  62   raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const;
  63
  64   // Convenience method that attempts to look up the frequency associated with
  65   // BB and print it to OS.
  66   raw_ostream &printBlockFreq(raw_ostream &OS,
  67                               const MachineBasicBlock *MBB) const;
  68
  69   uint64_t getEntryFreq() const;
  70
  71 };
  72
  73 }
  74
  75 #endif