include/llvm/Analysis/BlockFrequencyInfo.h

   1 //===------- BlockFrequencyInfo.h - Block 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_ANALYSIS_BLOCKFREQUENCYINFO_H
  15 #define LLVM_ANALYSIS_BLOCKFREQUENCYINFO_H
  16
  17 #include "llvm/Pass.h"
  18 #include "llvm/Support/BlockFrequency.h"
  19 #include <climits>
  20
  21 namespace llvm {
  22
  23 class BranchProbabilityInfo;
  24 template<class BlockT, class FunctionT, class BranchProbInfoT>
  25 class BlockFrequencyImpl;
  26
  27 /// BlockFrequencyInfo pass uses BlockFrequencyImpl implementation to estimate
  28 /// IR basic block frequencies.
  29 class BlockFrequencyInfo : public FunctionPass {
  30   typedef BlockFrequencyImpl<BasicBlock, Function, BranchProbabilityInfo>
  31   ImplType;
  32   std::unique_ptr<ImplType> BFI;
  33
  34 public:
  35   static char ID;
  36
  37   BlockFrequencyInfo();
  38
  39   ~BlockFrequencyInfo();
  40
  41   void getAnalysisUsage(AnalysisUsage &AU) const override;
  42
  43   bool runOnFunction(Function &F) override;
  44   void releaseMemory() override;
  45   void print(raw_ostream &O, const Module *M) const override;
  46   const Function *getFunction() const;
  47   void view() const;
  48
  49   /// getblockFreq - Return block frequency. Return 0 if we don't have the
  50   /// information. Please note that initial frequency is equal to ENTRY_FREQ. It
  51   /// means that we should not rely on the value itself, but only on the
  52   /// comparison to the other block frequencies. We do this to avoid using of
  53   /// floating points.
  54   BlockFrequency getBlockFreq(const BasicBlock *BB) const;
  55
  56   // Print the block frequency Freq to OS using the current functions entry
  57   // frequency to convert freq into a relative decimal form.
  58   raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const;
  59
  60   // Convenience method that attempts to look up the frequency associated with
  61   // BB and print it to OS.
  62   raw_ostream &printBlockFreq(raw_ostream &OS, const BasicBlock *BB) const;
  63
  64   uint64_t getEntryFreq() const;
  65
  66 };
  67
  68 }
  69
  70 #endif