Statistic.h revision 975f05852d15c98540b50de7df704d67e5a794cd 
1//===-- llvm/ADT/Statistic.h - Easy way to expose stats ---------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the 'Statistic' class, which is designed to be an easy way
11// to expose various metrics from passes.  These statistics are printed at the
12// end of a run (from llvm_shutdown), when the -stats command line option is
13// passed on the command line.
14//
15// This is useful for reporting information like the number of instructions
16// simplified, optimized or removed by various transformations, like this:
17//
18// static Statistic NumInstsKilled("gcse", "Number of instructions killed");
19//
20// Later, in the code: ++NumInstsKilled;
21//
22// NOTE: Statistics *must* be declared as global variables.
23//
24//===----------------------------------------------------------------------===//
25
26#ifndef LLVM_ADT_STATISTIC_H
27#define LLVM_ADT_STATISTIC_H
28
29namespace llvm {
30
31class Statistic {
32  const char *Name;
33  const char *Desc;
34  unsigned Value : 31;
35  bool Initialized : 1;
36public:
37  // Normal constructor, default initialize data item...
38  Statistic(const char *name, const char *desc)
39    : Name(name), Desc(desc), Value(0), Initialized(0) {
40  }
41
42  unsigned getValue() const { return Value; }
43  const char *getName() const { return Name; }
44  const char *getDesc() const { return Desc; }
45
46  // Allow use of this class as the value itself.
47  operator unsigned() const { return Value; }
48  const Statistic &operator=(unsigned Val) { Value = Val; return init(); }
49  const Statistic &operator++() { ++Value; return init(); }
50  unsigned operator++(int) { init(); return Value++; }
51  const Statistic &operator--() { --Value; return init(); }
52  unsigned operator--(int) { init(); return Value--; }
53  const Statistic &operator+=(const unsigned &V) { Value += V; return init(); }
54  const Statistic &operator-=(const unsigned &V) { Value -= V; return init(); }
55  const Statistic &operator*=(const unsigned &V) { Value *= V; return init(); }
56  const Statistic &operator/=(const unsigned &V) { Value /= V; return init(); }
57
58private:
59  Statistic &init() {
60    if (!Initialized) RegisterStatistic();
61    return *this;
62  }
63  void RegisterStatistic();
64};
65
66} // End llvm namespace
67
68#endif
69