1 //===-- Support/Statistic.h - Easy way to expose stats ----------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
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.
8 //===----------------------------------------------------------------------===//
10 // This file defines the 'Statistic' class, which is designed to be an easy way
11 // to expose various success metrics from passes. These statistics are printed
12 // at the end of a run, when the -stats command line option is enabled on the
15 // This is useful for reporting information like the number of instructions
16 // simplified, optimized or removed by various transformations, like this:
18 // static Statistic<> NumInstEliminated("GCSE - Number of instructions killed");
20 // Later, in the code: ++NumInstEliminated;
22 //===----------------------------------------------------------------------===//
24 #ifndef SUPPORT_STATISTIC_H
25 #define SUPPORT_STATISTIC_H
29 // StatisticBase - Nontemplated base class for Statistic<> class...
33 static unsigned NumStats;
35 StatisticBase(const char *name, const char *desc) : Name(name), Desc(desc) {
36 ++NumStats; // Keep track of how many stats are created...
38 virtual ~StatisticBase() {}
40 // destroy - Called by subclass dtor so that we can still invoke virtual
41 // functions on the subclass.
44 // printValue - Overridden by template class to print out the value type...
45 virtual void printValue(std::ostream &o) const = 0;
47 // hasSomeData - Return true if some data has been aquired. Avoid printing
48 // lots of zero counts.
50 virtual bool hasSomeData() const = 0;
53 // Statistic Class - templated on the data type we are monitoring...
54 template <typename DataType=unsigned>
55 class Statistic : private StatisticBase {
58 virtual void printValue(std::ostream &o) const { o << Value; }
59 virtual bool hasSomeData() const { return Value != DataType(); }
61 // Normal constructor, default initialize data item...
62 Statistic(const char *name, const char *desc)
63 : StatisticBase(name, desc), Value(DataType()) {}
65 // Constructor to provide an initial value...
66 Statistic(const DataType &Val, const char *name, const char *desc)
67 : StatisticBase(name, desc), Value(Val) {}
69 // Print information when destroyed, iff command line option is specified
70 ~Statistic() { destroy(); }
72 // Allow use of this class as the value itself...
73 operator DataType() const { return Value; }
74 const Statistic &operator=(DataType Val) { Value = Val; return *this; }
75 const Statistic &operator++() { ++Value; return *this; }
76 DataType operator++(int) { return Value++; }
77 const Statistic &operator+=(const DataType &V) { Value += V; return *this; }
78 const Statistic &operator-=(const DataType &V) { Value -= V; return *this; }