91 files changed, 142 insertions, 20 deletions

diff --git a/include/llvm/ADT/Statistic.h b/include/llvm/ADT/Statistic.h
index b54d10b9dd..26aac7bea6 100644
--- a/include/llvm/ADT/Statistic.h
+++ b/include/llvm/ADT/Statistic.h
@@ -51,7 +51,9 @@ public:
 
   // 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();
   }
@@ -106,6 +108,46 @@ public:
     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;
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 4fb9c5c8a0..aa45ac5958 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -63,13 +63,11 @@
 #include "llvm/Target/TargetMachine.h"
 using namespace llvm;
 
-#ifndef NDEBUG
 STATISTIC(NumFastIselSuccessIndependent, "Number of insts selected by "
           "target-independent selector");
 STATISTIC(NumFastIselSuccessTarget, "Number of insts selected by "
           "target-specific selector");
 STATISTIC(NumFastIselDead, "Number of dead insts removed on failure");
-#endif // NDEBUG
 
 /// startNewBlock - Set the current block to which generated machine
 /// instructions will be appended, and clear the local CSE map.
@@ -334,7 +332,7 @@ void FastISel::removeDeadCode(MachineBasicBlock::iterator I,
     MachineInstr *Dead = &*I;
     ++I;
     Dead->eraseFromParent();
-    DEBUG(++NumFastIselDead);
+    ++NumFastIselDead;
   }
   recomputeInsertPt();
 }
@@ -830,7 +828,7 @@ FastISel::SelectInstruction(const Instruction *I) {
 
   // First, try doing target-independent selection.
   if (SelectOperator(I, I->getOpcode())) {
-    DEBUG(++NumFastIselSuccessIndependent);
+    ++NumFastIselSuccessIndependent;
     DL = DebugLoc();
     return true;
   }
@@ -845,7 +843,7 @@ FastISel::SelectInstruction(const Instruction *I) {
   // Next, try calling the target to attempt to handle the instruction.
   SavedInsertPt = FuncInfo.InsertPt;
   if (TargetSelectInstruction(I)) {
-    DEBUG(++NumFastIselSuccessTarget);
+    ++NumFastIselSuccessTarget;
     DL = DebugLoc();
     return true;
   }
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 285625ef04..39a1f8a3d0 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -58,14 +58,13 @@
 #include <algorithm>
 using namespace llvm;
 
+STATISTIC(NumFastIselFailures, "Number of instructions fast isel failed on");
+STATISTIC(NumFastIselSuccess, "Number of instructions fast isel selected");
 STATISTIC(NumFastIselBlocks, "Number of blocks selected entirely by fast isel");
 STATISTIC(NumDAGBlocks, "Number of blocks selected using DAG");
-
-#ifndef NDEBUG
 STATISTIC(NumDAGIselRetries,"Number of times dag isel has to try another path");
-STATISTIC(NumFastIselFailures, "Number of instructions fast isel failed on");
-STATISTIC(NumFastIselSuccess, "Number of instructions fast isel selected");
 
+#ifndef NDEBUG
 static cl::opt<bool>
 EnableFastISelVerbose2("fast-isel-verbose2", cl::Hidden,
           cl::desc("Enable extra verbose messages in the \"fast\" "
@@ -1090,7 +1089,7 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
         // Try to select the instruction with FastISel.
         if (FastIS->SelectInstruction(Inst)) {
           --NumFastIselRemaining;
-          DEBUG(++NumFastIselSuccess);
+          ++NumFastIselSuccess;
           // If fast isel succeeded, skip over all the folded instructions, and
           // then see if there is a load right before the selected instructions.
           // Try to fold the load if so.
@@ -1106,7 +1105,7 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
             // If we succeeded, don't re-select the load.
             BI = llvm::next(BasicBlock::const_iterator(BeforeInst));
             --NumFastIselRemaining;
-            DEBUG(++NumFastIselSuccess);
+            ++NumFastIselSuccess;
           }
           continue;
         }
@@ -1145,21 +1144,20 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
           // Recompute NumFastIselRemaining as Selection DAG instruction
           // selection may have handled the call, input args, etc.
           unsigned RemainingNow = std::distance(Begin, BI);
-          (void) RemainingNow;
-          DEBUG(NumFastIselFailures += NumFastIselRemaining - RemainingNow);
-          DEBUG(NumFastIselRemaining = RemainingNow);
+          NumFastIselFailures += NumFastIselRemaining - RemainingNow;
+          NumFastIselRemaining = RemainingNow;
           continue;
         }
 
         if (isa<TerminatorInst>(Inst) && !isa<BranchInst>(Inst)) {
           // Don't abort, and use a different message for terminator misses.
-          DEBUG(NumFastIselFailures += NumFastIselRemaining);
+          NumFastIselFailures += NumFastIselRemaining;
           if (EnableFastISelVerbose || EnableFastISelAbort) {
             dbgs() << "FastISel missed terminator: ";
             Inst->dump();
           }
         } else {
-          DEBUG(NumFastIselFailures += NumFastIselRemaining);
+          NumFastIselFailures += NumFastIselRemaining;
           if (EnableFastISelVerbose || EnableFastISelAbort) {
             dbgs() << "FastISel miss: ";
             Inst->dump();
@@ -2357,7 +2355,7 @@ SelectCodeCommon(SDNode *NodeToMatch, const unsigned char *MatcherTable,
         DEBUG(errs() << "  Skipped scope entry (due to false predicate) at "
                      << "index " << MatcherIndexOfPredicate
                      << ", continuing at " << FailIndex << "\n");
-        DEBUG(++NumDAGIselRetries);
+        ++NumDAGIselRetries;
 
         // Otherwise, we know that this case of the Scope is guaranteed to fail,
         // move to the next case.
@@ -2938,7 +2936,7 @@ SelectCodeCommon(SDNode *NodeToMatch, const unsigned char *MatcherTable,
     // another child to try in the current 'Scope', otherwise pop it until we
     // find a case to check.
     DEBUG(errs() << "  Match failed at index " << CurrentOpcodeIndex << "\n");
-    DEBUG(++NumDAGIselRetries);
+    ++NumDAGIselRetries;
     while (1) {
       if (MatchScopes.empty()) {
         CannotYetSelect(NodeToMatch);
diff --git a/lib/Support/Statistic.cpp b/lib/Support/Statistic.cpp
index 3a6522101d..9c28176b73 100644
--- a/lib/Support/Statistic.cpp
+++ b/lib/Support/Statistic.cpp
@@ -40,7 +40,9 @@ namespace llvm { extern raw_ostream *CreateInfoOutputFile(); }
 /// what they did.
 ///
 static cl::opt<bool>
-Enabled("stats", cl::desc("Enable statistics output from program"));
+Enabled(
+    "stats",
+    cl::desc("Enable statistics output from program (available with Asserts)"));
 
 
 namespace {
@@ -142,6 +144,7 @@ void llvm::PrintStatistics(raw_ostream &OS) {
 }
 
 void llvm::PrintStatistics() {
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_STATS)
   StatisticInfo &Stats = *StatInfo;
 
   // Statistics not enabled?
@@ -151,4 +154,17 @@ void llvm::PrintStatistics() {
   raw_ostream &OutStream = *CreateInfoOutputFile();
   PrintStatistics(OutStream);
   delete &OutStream;   // Close the file.
+#else
+  // Check if the -stats option is set instead of checking
+  // !Stats.Stats.empty().  In release builds, Statistics operators
+  // do nothing, so stats are never Registered.
+  if (Enabled) {
+    // Get the stream to write to.
+    raw_ostream &OutStream = *CreateInfoOutputFile();
+    OutStream << "Statistics are disabled.  "
+            << "Build with asserts or with -DLLVM_ENABLE_STATS\n";
+    OutStream.flush();
+    delete &OutStream;   // Close the file.
+  }
+#endif
 }
diff --git a/test/Analysis/RegionInfo/block_sort.ll b/test/Analysis/RegionInfo/Stats/block_sort.ll
index ac77ab36e6..ac77ab36e6 100644
--- a/test/Analysis/RegionInfo/block_sort.ll
+++ b/