1 //===-- llvm/ADT/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<> NumInstsKilled("gcse", "Number of instructions killed");
20 // Later, in the code: ++NumInstsKilled;
22 //===----------------------------------------------------------------------===//
24 #ifndef LLVM_ADT_STATISTIC_H
25 #define LLVM_ADT_STATISTIC_H
28 #include "llvm/Support/Compiler.h"
32 // StatisticBase - Nontemplated base class for Statistic<> class...
36 static unsigned NumStats;
38 StatisticBase(const char *name, const char *desc) : Name(name), Desc(desc) {
39 ++NumStats; // Keep track of how many stats are created...
41 // Out of line virtual dtor, to give the vtable etc a home.
42 virtual ~StatisticBase();
44 // destroy - Called by subclass dtor so that we can still invoke virtual
45 // functions on the subclass.
48 // printValue - Overridden by template class to print out the value type...
49 virtual void printValue(std::ostream &o) const = 0;
51 // hasSomeData - Return true if some data has been aquired. Avoid printing
52 // lots of zero counts.
54 virtual bool hasSomeData() const = 0;
57 // Statistic Class - templated on the data type we are monitoring...
58 template <typename DataType=unsigned>
59 class Statistic : private StatisticBase {
62 virtual void printValue(std::ostream &o) const { o << Value; }
63 virtual bool hasSomeData() const { return Value != DataType(); }
65 // Normal constructor, default initialize data item...
66 Statistic(const char *name, const char *desc)
67 : StatisticBase(name, desc), Value(DataType()) {}
69 // Constructor to provide an initial value...
70 Statistic(const DataType &Val, const char *name, const char *desc)
71 : StatisticBase(name, desc), Value(Val) {}
73 // Print information when destroyed, iff command line option is specified
74 ~Statistic() { destroy(); }
76 // Allow use of this class as the value itself...
77 operator DataType() const { return Value; }
78 const Statistic &operator=(DataType Val) { Value = Val; return *this; }
79 const Statistic &operator++() { ++Value; return *this; }
80 DataType operator++(int) { return Value++; }
81 const Statistic &operator--() { --Value; return *this; }
82 DataType operator--(int) { return Value--; }
83 const Statistic &operator+=(const DataType &V) { Value += V; return *this; }
84 const Statistic &operator-=(const DataType &V) { Value -= V; return *this; }
85 const Statistic &operator*=(const DataType &V) { Value *= V; return *this; }
86 const Statistic &operator/=(const DataType &V) { Value /= V; return *this; }
89 EXTERN_TEMPLATE_INSTANTIATION(class Statistic<unsigned>);
91 } // End llvm namespace