Statistic.h revision cf84504d7a86808117f67264ad5cfab8f5a139bc 
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;
35  static unsigned NumStats;
36public:
37  // Normal constructor, default initialize data item...
38  Statistic(const char *name, const char *desc)
39    : Name(name), Desc(desc), Value(0) {
40    ++NumStats;  // Keep track of how many stats are created...
41  }
42
43  // Print information when destroyed, iff command line option is specified
44  ~Statistic();
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 *this; }
49  const Statistic &operator++() { ++Value; return *this; }
50  unsigned operator++(int) { return Value++; }
51  const Statistic &operator--() { --Value; return *this; }
52  unsigned operator--(int) { return Value--; }
53  const Statistic &operator+=(const unsigned &V) { Value += V; return *this; }
54  const Statistic &operator-=(const unsigned &V) { Value -= V; return *this; }
55  const Statistic &operator*=(const unsigned &V) { Value *= V; return *this; }
56  const Statistic &operator/=(const unsigned &V) { Value /= V; return *this; }
57};
58
59} // End llvm namespace
60
61#endif
62