Initial checkin of Statistic class

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2599 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 69 insertions, 0 deletions

diff --git a/include/llvm/ADT/Statistic.h b/include/llvm/ADT/Statistic.h
new file mode 100644
index 0000000000..5c464865ed
--- /dev/null
+++ b/include/llvm/ADT/Statistic.h
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+//===-- Support/StatisticReporter.h - Easy way to expose stats ---*- C++ -*-==//
+//
+// This file defines the 'Statistic' class, which is designed to be an easy way
+// to expose various success metrics from passes.  These statistics are printed
+// at the end of a run, when the -stats command line option is enabled on the
+// command line.
+//
+// This is useful for reporting information like the number of instructions
+// simplified, optimized or removed by various transformations, like this:
+//
+// static Statistic<> NumInstEliminated("GCSE - Number of instructions killed");
+//
+// Later, in the code: ++NumInstEliminated;
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_STATISTIC_REPORTER_H
+#define SUPPORT_STATISTIC_REPORTER_H
+
+#include <iosfwd>
+
+// StatisticBase - Nontemplated base class for Statistic<> class...
+class StatisticBase {
+  const char *Name;
+protected:
+  StatisticBase(const char *name) : Name(name) {}
+  virtual ~StatisticBase() {}
+
+  // destroy - Called by subclass dtor so that we can still invoke virtual
+  // functions on the subclass.
+  void destroy() const;
+
+  // printValue - Overridden by template class to print out the value type...
+  virtual void printValue(ostream &o) const = 0;
+
+  // hasSomeData - Return true if some data has been aquired.  Avoid printing
+  // lots of zero counts.
+  //
+  virtual bool hasSomeData() const = 0;
+};
+
+// Statistic Class - templated on the data type we are monitoring...
+template <typename DataType=unsigned>
+class Statistic : private StatisticBase {
+  DataType Value;
+
+  virtual void printValue(ostream &o) const { o << Value; }
+  virtual bool hasSomeData() const { return Value != DataType(); }
+public:
+  // Normal constructor, default initialize data item...
+  Statistic(const char *name) : StatisticBase(name), Value(DataType()) {}
+
+  // Constructor to provide an initial value...
+  Statistic(const DataType &Val, const char *name)
+    : StatisticBase(name), Value(Val) {}
+
+  // Print information when destroyed, iff command line option is specified
+  ~Statistic() { destroy(); }
+
+  // Allow use of this class as the value itself...
+  inline operator DataType() const { return Value; }
+  inline const DataType &operator=(DataType Val) { Value = Val; return Value; }
+  inline const DataType &operator++() { return ++Value; }
+  inline DataType operator++(int) { return Value++; }
+  inline const DataType &operator+=(const DataType &V) { return Value += V; }
+  inline const DataType &operator-=(const DataType &V) { return Value -= V; }
+};
+
+#endif