ProfileInfo.h revision 858cb8a5e07d4fe4b516a99eef7e8c028516a679 
1//===- llvm/Analysis/ProfileInfo.h - Profile Info Interface -----*- 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// This file defines the generic ProfileInfo interface, which is used as the
11// common interface used by all clients of profiling information, and
12// implemented either by making static guestimations, or by actually reading in
13// profiling information gathered by running the program.
14//
15// Note that to be useful, all profile-based optimizations should preserve
16// ProfileInfo, which requires that they notify it when changes to the CFG are
17// made.
18//
19//===----------------------------------------------------------------------===//
20
21#ifndef LLVM_ANALYSIS_PROFILEINFO_H
22#define LLVM_ANALYSIS_PROFILEINFO_H
23
24#include <string>
25#include <map>
26
27namespace llvm {
28  class BasicBlock;
29  class Function;
30  class Pass;
31
32  /// ProfileInfo Class - This class holds and maintains edge profiling
33  /// information for some unit of code.
34  class ProfileInfo {
35  public:
36    // Types for handling profiling information.
37    typedef std::pair<const BasicBlock*, const BasicBlock*> Edge;
38
39  protected:
40    // EdgeCounts - Count the number of times a transition between two blocks is
41    // executed.  As a special case, we also hold an edge from the null
42    // BasicBlock to the entry block to indicate how many times the function was
43    // entered.
44    std::map<Edge, unsigned> EdgeCounts;
45  public:
46    static char ID; // Class identification, replacement for typeinfo
47    virtual ~ProfileInfo();  // We want to be subclassed
48
49    //===------------------------------------------------------------------===//
50    /// Profile Information Queries
51    ///
52    unsigned getExecutionCount(const Function *F) const;
53
54    unsigned getExecutionCount(const BasicBlock *BB) const;
55
56    unsigned getEdgeWeight(const BasicBlock *Src,
57                           const BasicBlock *Dest) const {
58      std::map<Edge, unsigned>::const_iterator I =
59        EdgeCounts.find(std::make_pair(Src, Dest));
60      return I != EdgeCounts.end() ? I->second : 0;
61    }
62
63    //===------------------------------------------------------------------===//
64    /// Analysis Update Methods
65    ///
66
67  };
68
69  /// createProfileLoaderPass - This function returns a Pass that loads the
70  /// profiling information for the module from the specified filename, making
71  /// it available to the optimizers.
72  Pass *createProfileLoaderPass(const std::string &Filename);
73} // End llvm namespace
74
75#endif
76