1 //===-- Support/Statistic.h - Easy way to expose stats ----------*- C++ -*-===//
3 // This file defines the 'Statistic' class, which is designed to be an easy way
4 // to expose various success metrics from passes. These statistics are printed
5 // at the end of a run, when the -stats command line option is enabled on the
8 // This is useful for reporting information like the number of instructions
9 // simplified, optimized or removed by various transformations, like this:
11 // static Statistic<> NumInstEliminated("GCSE - Number of instructions killed");
13 // Later, in the code: ++NumInstEliminated;
15 //===----------------------------------------------------------------------===//
17 #ifndef SUPPORT_STATISTIC_H
18 #define SUPPORT_STATISTIC_H
22 // DebugFlag - This boolean is set to true if the '-debug' command line option
23 // is specified. This should probably not be referenced directly, instead, use
24 // the DEBUG macro below.
26 extern bool DebugFlag;
28 // DEBUG macro - This macro should be used by passes to emit debug information.
29 // In the '-debug' option is specified on the commandline, and if this is a
30 // debug build, then the code specified as the option to the macro will be
31 // executed. Otherwise it will not be. Example:
33 // DEBUG(cerr << "Bitset contains: " << Bitset << "\n");
39 do { if (DebugFlag) { X; } } while (0)
43 // StatisticBase - Nontemplated base class for Statistic<> class...
47 static unsigned NumStats;
49 StatisticBase(const char *name, const char *desc) : Name(name), Desc(desc) {
50 ++NumStats; // Keep track of how many stats are created...
52 virtual ~StatisticBase() {}
54 // destroy - Called by subclass dtor so that we can still invoke virtual
55 // functions on the subclass.
58 // printValue - Overridden by template class to print out the value type...
59 virtual void printValue(std::ostream &o) const = 0;
61 // hasSomeData - Return true if some data has been aquired. Avoid printing
62 // lots of zero counts.
64 virtual bool hasSomeData() const = 0;
67 // Statistic Class - templated on the data type we are monitoring...
68 template <typename DataType=unsigned>
69 class Statistic : private StatisticBase {
72 virtual void printValue(std::ostream &o) const { o << Value; }
73 virtual bool hasSomeData() const { return Value != DataType(); }
75 // Normal constructor, default initialize data item...
76 Statistic(const char *name, const char *desc)
77 : StatisticBase(name, desc), Value(DataType()) {}
79 // Constructor to provide an initial value...
80 Statistic(const DataType &Val, const char *name, const char *desc)
81 : StatisticBase(name, desc), Value(Val) {}
83 // Print information when destroyed, iff command line option is specified
84 ~Statistic() { destroy(); }
86 // Allow use of this class as the value itself...
87 operator DataType() const { return Value; }
88 const Statistic &operator=(DataType Val) { Value = Val; return *this; }
89 const Statistic &operator++() { ++Value; return *this; }
90 DataType operator++(int) { return Value++; }
91 const Statistic &operator+=(const DataType &V) { Value += V; return *this; }
92 const Statistic &operator-=(const DataType &V) { Value -= V; return *this; }