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 BlockFrequencyInfoImpl;
25 
26 /// BlockFrequencyInfo pass uses BlockFrequencyInfoImpl implementation to
27 /// estimate IR basic block frequencies.
28 class BlockFrequencyInfo : public FunctionPass {
29   typedef BlockFrequencyInfoImpl<BasicBlock> ImplType;
30   std::unique_ptr<ImplType> BFI;
31 
32 public:
33   static char ID;
34 
35   BlockFrequencyInfo();
36 
37   ~BlockFrequencyInfo() override;
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