BlockFrequencyInfo.h revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
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
21namespace llvm {
22
23class BranchProbabilityInfo;
24template <class BlockT> class BlockFrequencyInfoImpl;
25
26/// BlockFrequencyInfo pass uses BlockFrequencyInfoImpl implementation to
27/// estimate IR basic block frequencies.
28class BlockFrequencyInfo : public FunctionPass {
29  typedef BlockFrequencyInfoImpl<BasicBlock> ImplType;
30  std::unique_ptr<ImplType> BFI;
31
32public:
33  static char ID;
34
35  BlockFrequencyInfo();
36
37  ~BlockFrequencyInfo();
38
39  void getAnalysisUsage(AnalysisUsage &AU) const override;
40
41  bool runOnFunction(Function &F) override;
42  void releaseMemory() override;
43  void print(raw_ostream &O, const Module *M) const override;
44  const Function *getFunction() const;
45  void view() const;
46
47  /// getblockFreq - Return block frequency. Return 0 if we don't have the
48  /// information. Please note that initial frequency is equal to ENTRY_FREQ. It
49  /// means that we should not rely on the value itself, but only on the
50  /// comparison to the other block frequencies. We do this to avoid using of
51  /// floating points.
52  BlockFrequency getBlockFreq(const BasicBlock *BB) const;
53
54  // Print the block frequency Freq to OS using the current functions entry
55  // frequency to convert freq into a relative decimal form.
56  raw_ostream &printBlockFreq(raw_ostream &OS, const BlockFrequency Freq) const;
57
58  // Convenience method that attempts to look up the frequency associated with
59  // BB and print it to OS.
60  raw_ostream &printBlockFreq(raw_ostream &OS, const BasicBlock *BB) const;
61
62  uint64_t getEntryFreq() const;
63
64};
65
66}
67
68#endif
69