Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)

[oota-llvm.git] / include / llvm / ADT / Statistic.h

diff --git a/include/llvm/ADT/Statistic.h b/include/llvm/ADT/Statistic.h
index 484ff5fbebc6ca5cc5f17cc3e62d3f13d4525bc7..d98abc375e8ac3a232a1b353dcfcb1d9b08b95cf 100644 (file)
--- a/include/llvm/ADT/Statistic.h
+++ b/include/llvm/ADT/Statistic.h
@@ -26,83 +26,134 @@
 #ifndef LLVM_ADT_STATISTIC_H
 #define LLVM_ADT_STATISTIC_H
 
-#include "llvm/System/Atomic.h"
+#include "llvm/Support/Atomic.h"
+#include "llvm/Support/Valgrind.h"
 
 namespace llvm {
+class raw_ostream;
 
 class Statistic {
 public:
   const char *Name;
   const char *Desc;
-  unsigned Value;
+  volatile llvm::sys::cas_flag Value;
   bool Initialized;
 
-  unsigned getValue() const { return Value; }
+  llvm::sys::cas_flag getValue() const { return Value; }
   const char *getName() const { return Name; }
   const char *getDesc() const { return Desc; }
 
   /// construct - This should only be called for non-global statistics.
   void construct(const char *name, const char *desc) {
     Name = name; Desc = desc;
-    Value = 0; Initialized = 0;
+    Value = 0; Initialized = false;
   }
 
   // Allow use of this class as the value itself.
   operator unsigned() const { return Value; }
-  const Statistic &operator=(unsigned Val) {
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_STATS)
+   const Statistic &operator=(unsigned Val) {
     Value = Val;
     return init();
   }
-  
+
   const Statistic &operator++() {
+    // FIXME: This function and all those that follow carefully use an
+    // atomic operation to update the value safely in the presence of
+    // concurrent accesses, but not to read the return value, so the
+    // return value is not thread safe.
     sys::AtomicIncrement(&Value);
     return init();
   }
-  
+
   unsigned operator++(int) {
     init();
     unsigned OldValue = Value;
     sys::AtomicIncrement(&Value);
     return OldValue;
   }
-  
+
   const Statistic &operator--() {
     sys::AtomicDecrement(&Value);
     return init();
   }
-  
+
   unsigned operator--(int) {
     init();
     unsigned OldValue = Value;
     sys::AtomicDecrement(&Value);
     return OldValue;
   }
-  
+
   const Statistic &operator+=(const unsigned &V) {
+    if (!V) return *this;
     sys::AtomicAdd(&Value, V);
     return init();
   }
-  
+
   const Statistic &operator-=(const unsigned &V) {
+    if (!V) return *this;
     sys::AtomicAdd(&Value, -V);
     return init();
   }
-  
+
   const Statistic &operator*=(const unsigned &V) {
     sys::AtomicMul(&Value, V);
     return init();
   }
-  
+
   const Statistic &operator/=(const unsigned &V) {
     sys::AtomicDiv(&Value, V);
     return init();
   }
 
+#else  // Statistics are disabled in release builds.
+
+  const Statistic &operator=(unsigned Val) {
+    return *this;
+  }
+
+  const Statistic &operator++() {
+    return *this;
+  }
+
+  unsigned operator++(int) {
+    return 0;
+  }
+
+  const Statistic &operator--() {
+    return *this;
+  }
+
+  unsigned operator--(int) {
+    return 0;
+  }
+
+  const Statistic &operator+=(const unsigned &V) {
+    return *this;
+  }
+
+  const Statistic &operator-=(const unsigned &V) {
+    return *this;
+  }
+
+  const Statistic &operator*=(const unsigned &V) {
+    return *this;
+  }
+
+  const Statistic &operator/=(const unsigned &V) {
+    return *this;
+  }
+
+#endif  // !defined(NDEBUG) || defined(LLVM_ENABLE_STATS)
+
 protected:
   Statistic &init() {
     bool tmp = Initialized;
     sys::MemoryFence();
     if (!tmp) RegisterStatistic();
+    TsanHappensAfter(this);
     return *this;
   }
   void RegisterStatistic();
@@ -113,6 +164,18 @@ protected:
 #define STATISTIC(VARNAME, DESC) \
   static llvm::Statistic VARNAME = { DEBUG_TYPE, DESC, 0, 0 }
 
+/// \brief Enable the collection and printing of statistics.
+void EnableStatistics();
+
+/// \brief Check if statistics are enabled.
+bool AreStatisticsEnabled();
+
+/// \brief Print statistics to the file returned by CreateInfoOutputFile().
+void PrintStatistics();
+
+/// \brief Print statistics to the given output stream.
+void PrintStatistics(raw_ostream &OS);
+
 } // End llvm namespace
 
 #endif