ProfileInfo.h revision 96135b617a5c752ea98388d0ed4a289c47c147b3 
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. (This is not implemented yet.)
18//
19//===----------------------------------------------------------------------===//
20
21#ifndef LLVM_ANALYSIS_PROFILEINFO_H
22#define LLVM_ANALYSIS_PROFILEINFO_H
23
24#include "llvm/BasicBlock.h"
25#include <cassert>
26#include <string>
27#include <map>
28
29namespace llvm {
30  class Function;
31  class Pass;
32
33  /// ProfileInfo Class - This class holds and maintains profiling
34  /// information for some unit of code.
35  class ProfileInfo {
36  public:
37    // Types for handling profiling information.
38    typedef std::pair<const BasicBlock*, const BasicBlock*> Edge;
39    typedef std::pair<Edge, double> EdgeWeight;
40    typedef std::map<Edge, double> EdgeWeights;
41    typedef std::map<const BasicBlock*, double> BlockCounts;
42
43  protected:
44    // EdgeInformation - Count the number of times a transition between two
45    // blocks is executed. As a special case, we also hold an edge from the
46    // null BasicBlock to the entry block to indicate how many times the
47    // function was entered.
48    std::map<const Function*, EdgeWeights> EdgeInformation;
49
50    // BlockInformation - Count the number of times a block is executed.
51    std::map<const Function*, BlockCounts> BlockInformation;
52
53    // FunctionInformation - Count the number of times a function is executed.
54    std::map<const Function*, double> FunctionInformation;
55  public:
56    static char ID; // Class identification, replacement for typeinfo
57    virtual ~ProfileInfo();  // We want to be subclassed
58
59    // MissingValue - The value that is returned for execution counts in case
60    // no value is available.
61    static const double MissingValue;
62
63    // getFunction() - Returns the Function for an Edge, checking for validity.
64    static const Function* getFunction(Edge e) {
65      assert(e.second && "Invalid ProfileInfo::Edge");
66      return e.second->getParent();
67    }
68
69    // getEdge() - Creates an Edge from two BasicBlocks.
70    static Edge getEdge(const BasicBlock *Src, const BasicBlock *Dest) {
71      return std::make_pair(Src, Dest);
72    }
73
74    //===------------------------------------------------------------------===//
75    /// Profile Information Queries
76    ///
77    double getExecutionCount(const Function *F);
78
79    double getExecutionCount(const BasicBlock *BB);
80
81    double getEdgeWeight(Edge e) const {
82      std::map<const Function*, EdgeWeights>::const_iterator J =
83        EdgeInformation.find(getFunction(e));
84      if (J == EdgeInformation.end()) return MissingValue;
85
86      EdgeWeights::const_iterator I = J->second.find(e);
87      if (I == J->second.end()) return MissingValue;
88
89      return I->second;
90    }
91
92    EdgeWeights &getEdgeWeights (const Function *F) {
93      return EdgeInformation[F];
94    }
95
96    //===------------------------------------------------------------------===//
97    /// Analysis Update Methods
98    ///
99
100  };
101
102  /// createProfileLoaderPass - This function returns a Pass that loads the
103  /// profiling information for the module from the specified filename, making
104  /// it available to the optimizers.
105  Pass *createProfileLoaderPass(const std::string &Filename);
106} // End llvm namespace
107
108#endif
109