Subzero: Enhance the timer dump format.

src/IceTimerTree.cpp

 //===- subzero/src/IceTimerTree.cpp - Pass timer defs ---------------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines the TimerTree class, which tracks flat and
@@ skipping 27 matching lines @@
 TimerIdT TimerStack::getTimerID(const IceString &Name) {
   if (IDsIndex.find(Name) == IDsIndex.end()) {
     IDsIndex[Name] = IDs.size();
     IDs.push_back(Name);
   }
   return IDsIndex[Name];
 }
 
 // Pushes a new marker onto the timer stack.
 void TimerStack::push(TimerIdT ID) {
-  update();
+  const bool UpdateCounts = false;
+  update(UpdateCounts);
   if (Nodes[StackTop].Children.size() <= ID)
     Nodes[StackTop].Children.resize(ID + 1);
   if (Nodes[StackTop].Children[ID] == 0) {
     TTindex Size = Nodes.size();
     Nodes[StackTop].Children[ID] = Size;
     Nodes.resize(Size + 1);
     Nodes[Size].Parent = StackTop;
     Nodes[Size].Interior = ID;
   }
   StackTop = Nodes[StackTop].Children[ID];
 }
 
 // Pop the top marker from the timer stack.  Validates via assert()
 // that the expected marker is popped.
 void TimerStack::pop(TimerIdT ID) {
-  update();
+  const bool UpdateCounts = true;
+  update(UpdateCounts);
   assert(StackTop);
   assert(Nodes[StackTop].Parent < StackTop);
   // Verify that the expected ID is being popped.
   assert(Nodes[StackTop].Interior == ID);
   (void)ID;
   // Verify that the parent's child points to the current stack top.
   assert(Nodes[Nodes[StackTop].Parent].Children[ID] == StackTop);
   StackTop = Nodes[StackTop].Parent;
 }
 
 // At a state change (e.g. push or pop), updates the flat and
 // cumulative timings for everything on the timer stack.
-void TimerStack::update() {
+void TimerStack::update(bool UpdateCounts) {
   ++StateChangeCount;
   // Whenever the stack is about to change, we grab the time delta
   // since the last change and add it to all active cumulative
   // elements and to the flat element for the top of the stack.
   double Current = timestamp();
   double Delta = Current - LastTimestamp;
   if (StackTop) {
     TimerIdT Leaf = Nodes[StackTop].Interior;
-    if (Leaf >= LeafTimes.size())
+    if (Leaf >= LeafTimes.size()) {
       LeafTimes.resize(Leaf + 1);
+      LeafCounts.resize(Leaf + 1);
+    }
     LeafTimes[Leaf] += Delta;
+    if (UpdateCounts)
+      ++LeafCounts[Leaf];
   }
   TTindex Prefix = StackTop;
   while (Prefix) {
     Nodes[Prefix].Time += Delta;
+    // Only update a leaf node count, not the internal node counts.
+    if (UpdateCounts && Prefix == StackTop)
+      ++Nodes[Prefix].UpdateCount;
     TTindex Next = Nodes[Prefix].Parent;
     assert(Next < Prefix);
     Prefix = Next;
   }
   // Capture the next timestamp *after* the updates are finished.
   // This minimizes how much the timer can perturb the reported
   // timing.  The numbers may not sum to 100%, and the missing amount
   // is indicative of the overhead of timing.
   LastTimestamp = timestamp();
 }
 
 void TimerStack::reset() {
   StateChangeCount = 0;
   FirstTimestamp = LastTimestamp = timestamp();
   LeafTimes.assign(LeafTimes.size(), 0);
+  LeafCounts.assign(LeafCounts.size(), 0);
   for (TimerTreeNode &Node : Nodes) {
     Node.Time = 0;
+    Node.UpdateCount = 0;
   }
 }
 
 namespace {
 
 typedef std::multimap<double, IceString> DumpMapType;
 
 // Dump the Map items in reverse order of their time contribution.
 void dumpHelper(Ostream &Str, const DumpMapType &Map, double TotalTime) {
   // TODO(stichnot): Use llvm::make_range with LLVM 3.5.
   for (auto I = Map.rbegin(), E = Map.rend(); I != E; ++I) {
     char buf[80];
     snprintf(buf, llvm::array_lengthof(buf), "  %10.6f (%4.1f%%): ", I->first,
              I->first * 100 / TotalTime);
     Str << buf << I->second << "\n";
   }
 }
 
+// Write a printf() format string into Buf[], in the format "[%5lu] ",
+// where "5" is actually the number of digits in MaxVal.  E.g.,
+//   MaxVal=0     ==> "[%1lu] "
+//   MaxVal=5     ==> "[%1lu] "
+//   MaxVal=9876  ==> "[%4lu] "
+void makePrintfFormatString(char *Buf, size_t BufLen, size_t MaxVal) {
+  int NumDigits = 0;
+  do {
+    ++NumDigits;
+    MaxVal /= 10;
+  } while (MaxVal);
+  snprintf(Buf, BufLen, "[%%%dlu] ", NumDigits);
+}
+
 } // end of anonymous namespace
 
 void TimerStack::dump(Ostream &Str, bool DumpCumulative) {
-  update();
+  const bool UpdateCounts = true;
+  update(UpdateCounts);
   double TotalTime = LastTimestamp - FirstTimestamp;
   assert(TotalTime);
+  char FmtString[30], PrefixStr[30];
   if (DumpCumulative) {
     Str << Name << " - Cumulative times:\n";
+    size_t MaxInternalCount = 0;
+    for (TimerTreeNode &Node : Nodes)
+      MaxInternalCount = std::max(MaxInternalCount, Node.UpdateCount);
+    makePrintfFormatString(FmtString, llvm::array_lengthof(FmtString),
+                           MaxInternalCount);
+
     DumpMapType CumulativeMap;
     for (TTindex i = 1; i < Nodes.size(); ++i) {
       TTindex Prefix = i;
       IceString Suffix = "";
       while (Prefix) {
         if (Suffix.empty())
           Suffix = IDs[Nodes[Prefix].Interior];
         else
           Suffix = IDs[Nodes[Prefix].Interior] + "." + Suffix;
         assert(Nodes[Prefix].Parent < Prefix);
         Prefix = Nodes[Prefix].Parent;
       }
-      CumulativeMap.insert(std::make_pair(Nodes[i].Time, Suffix));
+      snprintf(PrefixStr, llvm::array_lengthof(PrefixStr), FmtString,
+               Nodes[i].UpdateCount);
+      CumulativeMap.insert(std::make_pair(Nodes[i].Time, PrefixStr + Suffix));
     }
     dumpHelper(Str, CumulativeMap, TotalTime);
   }
   Str << Name << " - Flat times:\n";
+  size_t MaxLeafCount = 0;
+  for (size_t Count : LeafCounts)
+    MaxLeafCount = std::max(MaxLeafCount, Count);
+  makePrintfFormatString(FmtString, llvm::array_lengthof(FmtString),
+                         MaxLeafCount);
   DumpMapType FlatMap;
   for (TimerIdT i = 0; i < LeafTimes.size(); ++i) {
-    FlatMap.insert(std::make_pair(LeafTimes[i], IDs[i]));
+    if (LeafCounts[i]) {
+      snprintf(PrefixStr, llvm::array_lengthof(PrefixStr), FmtString,
+               LeafCounts[i]);
+      FlatMap.insert(std::make_pair(LeafTimes[i], PrefixStr + IDs[i]));
+    }
   }
   dumpHelper(Str, FlatMap, TotalTime);
   Str << "Number of timer updates: " << StateChangeCount << "\n";
 }
 
 double TimerStack::timestamp() {
   // TODO: Implement in terms of std::chrono for C++11.
   return llvm::TimeRecord::getCurrentTime(false).getWallTime();
 }
 
 } // end of namespace Ice