BlockFrequencyInfo.h revision e2058ff5bd4fa0397b57f6bdd84e5a5aa2343433 
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 FunctionT, class BranchProbInfoT>
25class BlockFrequencyImpl;
26
27/// BlockFrequencyInfo pass uses BlockFrequencyImpl implementation to estimate
28/// IR basic block frequencies.
29class BlockFrequencyInfo : public FunctionPass {
30
31  BlockFrequencyImpl<BasicBlock, Function, BranchProbabilityInfo> *BFI;
32
33public:
34  static char ID;
35
36  BlockFrequencyInfo();
37
38  ~BlockFrequencyInfo();
39
40  void getAnalysisUsage(AnalysisUsage &AU) const;
41
42  bool runOnFunction(Function &F);
43  void print(raw_ostream &O, const Module *M) const;
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
55}
56
57#endif
58