Timer: Track Name and Description.

[MatzeB]

Summary

Currently the "names" of timers are something like "DAG Combining after legalize types", this is more of a description than a name and unwieldy when exporting into machine readable formats like JSON. Call the current timer names descriptions and add a new name field with a short programming language identifier like name.

[vsk]

This looks good! I only have nits. I assume clang will need some updates when you land this?

lib/IR/LegacyPassManager.cpp

452

Bikeshed: maybe "timing_info" for the name here? (I don't have a hard '-1' to just keeping "pass".)

lib/Support/Timer.cpp

214

getNamedRegionTimer has no coverage -- it looks safe to delete in a prep commit.

[MatzeB]

Thanks for the review, yes I have a clang patch as well.

lib/IR/LegacyPassManager.cpp

452

This will result in names like: time.pass.Loop Versioning which I find nicer than time.timing_info.Loop Versioning, don't you think?
(This also shows that unfortunately our pass "names" have the same problem that they are more like descriptions, but as far as I see it that problem will solve itself once the new pass manager has landed which will use the class names of the passes).

lib/Support/Timer.cpp

214

Yes that is https://reviews.llvm.org/D25582 (some bits of that are visible here as well).

[vsk]

Could you either delete Timer::getName(), or audit it / upgrade its uses? There is no coverage for it either, so it can probably go along with getNamedRegionTimer.

It looks like this patch is NFCI, but it might help to have some kind of test that ensures getName() and getDescription() return something reasonable. Maybe in unittests/Support/TimerTests?

lib/IR/LegacyPassManager.cpp

452

Sure. I had missed the 'time.' prefix.

[MatzeB]

In D25583#569843, @vsk wrote:

Could you either delete Timer::getName(), or audit it / upgrade its uses? There is no coverage for it either, so it can probably go along with getNamedRegionTimer.

Good point. Removing it produces no compile error here, so I think it is indeed unused. However being the only accessor function to this information I'd rather not delete it.

[vsk]

Lgtm.

[bruno]

This is great Matthias. Thank for working on this.

LGTM

[echristo]

LGTM.

-eric

docs/ReleaseNotes.rst

 
 .. NOTE
    For small 1-3 sentence descriptions, just add an entry at the end of
    this list. If your description won't fit comfortably in one bullet
    point (e.g. maybe you would like to give an example of the
    functionality, or simply have a lot to talk about), see the `NOTE` below
    for adding a new subsection.
 
-* ... next change ...
+* The Timer related APIs now expect a Name and Description. When upgrading code
+  the previously used names should become descriptions and a short name in the
+  style of a programming language identifier should be added.
 
 .. NOTE
    If you would like to document a larger change, then you can add a
    subsection about it right here. You can copy the following boilerplate
    and un-indent it (the indentation causes it to be inside this comment).
 
    Special New Feature
    -------------------

include/llvm/CodeGen/AsmPrinter.h

private:
   bool VerboseAsm;
   static char ID;
 
   /// If VerboseAsm is set, a pointer to the loop info for this function.
   MachineLoopInfo *LI;
 
   struct HandlerInfo {
     AsmPrinterHandler *Handler;
-    const char *TimerName, *TimerGroupName;
+    const char *TimerName;
+    const char *TimerDescription;
+    const char *TimerGroupName;
+    const char *TimerGroupDescription;
     HandlerInfo(AsmPrinterHandler *Handler, const char *TimerName,
-                const char *TimerGroupName)
+                const char *TimerDescription, const char *TimerGroupName,
+                const char *TimerGroupDescription)
         : Handler(Handler), TimerName(TimerName),
-          TimerGroupName(TimerGroupName) {}
+          TimerDescription(TimerDescription), TimerGroupName(TimerGroupName),
+          TimerGroupDescription(TimerGroupDescription) {}
   };
   /// A vector of all debug/EH info emitters we should use. This vector
   /// maintains ownership of the emitters.
   SmallVector<HandlerInfo, 1> Handlers;
 
   /// If the target supports dwarf debug info, this pointer is non-null.
   DwarfDebug *DD;
 

include/llvm/Support/Timer.h

 /// the Timer will print the amount of time it has captured to standard error
 /// when the last timer is destroyed, otherwise it is printed when its
 /// TimerGroup is destroyed.  Timers do not print their information if they are
 /// never started.
 class Timer {
   TimeRecord Time;          ///< The total time captured.
   TimeRecord StartTime;     ///< The time startTimer() was last called.
   std::string Name;         ///< The name of this time variable.
+  std::string Description;  ///< Description of this time variable.
   bool Running;             ///< Is the timer currently running?
   bool Triggered;           ///< Has the timer ever been triggered?
   TimerGroup *TG = nullptr; ///< The TimerGroup this Timer is in.
 
   Timer **Prev;             ///< Pointer to \p Next of previous timer in group.
   Timer *Next;              ///< Next timer in the group.
 public:
-  explicit Timer(StringRef N) { init(N); }
-  Timer(StringRef N, TimerGroup &tg) { init(N, tg); }
+  explicit Timer(StringRef Name, StringRef Description) {
+    init(Name, Description);
+  }
+  Timer(StringRef Name, StringRef Description, TimerGroup &tg) {
+    init(Name, Description, tg);
+  }
   Timer(const Timer &RHS) {
     assert(!RHS.TG && "Can only copy uninitialized timers");
   }
   const Timer &operator=(const Timer &T) {
     assert(!TG && !T.TG && "Can only assign uninit timers");
     return *this;
   }
   ~Timer();
 
   /// Create an uninitialized timer, client must use 'init'.
   explicit Timer() {}
-  void init(StringRef N);
-  void init(StringRef N, TimerGroup &tg);
+  void init(StringRef Name, StringRef Description);
+  void init(StringRef Name, StringRef Description, TimerGroup &tg);
 
   const std::string &getName() const { return Name; }
+  const std::string &getDescription() const { return Description; }
   bool isInitialized() const { return TG != nullptr; }
 
   /// Check if the timer is currently running.
   bool isRunning() const { return Running; }
 
   /// Check if startTimer() has ever been called on this timer.
   bool hasTriggered() const { return Triggered; }
 
public:
   }
 };
 
 /// This class is basically a combination of TimeRegion and Timer.  It allows
 /// you to declare a new timer, AND specify the region to time, all in one
 /// statement.  All timers with the same name are merged.  This is primarily
 /// used for debugging and for hunting performance problems.
 struct NamedRegionTimer : public TimeRegion {
-  explicit NamedRegionTimer(StringRef Name,
-                            bool Enabled = true);
-  explicit NamedRegionTimer(StringRef Name, StringRef GroupName,
-                            bool Enabled = true);
+  explicit NamedRegionTimer(StringRef Name, StringRef Description,
+                            StringRef GroupName,
+                            StringRef GroupDescription, bool Enabled = true);
 };
 
 /// The TimerGroup class is used to group together related timers into a single
 /// report that is printed when the TimerGroup is destroyed.  It is illegal to
 /// destroy a TimerGroup object before all of the Timers in it are gone.  A
 /// TimerGroup can be specified for a newly created timer in its constructor.
 class TimerGroup {
   std::string Name;
+  std::string Description;
   Timer *FirstTimer = nullptr; ///< First timer in the group.
   std::vector<std::pair<TimeRecord, std::string>> TimersToPrint;
 
   TimerGroup **Prev; ///< Pointer to Next field of previous timergroup in list.
   TimerGroup *Next;  ///< Pointer to next timergroup in list.
   TimerGroup(const TimerGroup &TG) = delete;
   void operator=(const TimerGroup &TG) = delete;
 
 public:
-  explicit TimerGroup(StringRef name);
+  explicit TimerGroup(StringRef Name, StringRef Description);
   ~TimerGroup();
 
-  void setName(StringRef name) { Name.assign(name.begin(), name.end()); }
+  void setName(StringRef NewName, StringRef NewDescription) {
+    Name.assign(NewName.begin(), NewName.end());
+    Description.assign(NewDescription.begin(), NewDescription.end());
+  }
 
   /// Print any started timers in this group and zero them.
   void print(raw_ostream &OS);
 
   /// This static method prints all timers and clears them all out.
   static void printAll(raw_ostream &OS);
 
 private:

lib/CodeGen/AsmPrinter/AsmPrinter.cpp

 #include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetLoweringObjectFile.h"
 #include "llvm/Target/TargetRegisterInfo.h"
 #include "llvm/Target/TargetSubtargetInfo.h"
 using namespace llvm;
 
 #define DEBUG_TYPE "asm-printer"
 
-static const char *const DWARFGroupName = "DWARF Emission";
-static const char *const DbgTimerName = "Debug Info Emission";
-static const char *const EHTimerName = "DWARF Exception Writer";
-static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables";
+static const char *const DWARFGroupName = "dwarf";
+static const char *const DWARFGroupDescription = "DWARF Emission";
+static const char *const DbgTimerName = "emit";
+static const char *const DbgTimerDescription = "Debug Info Emission";
+static const char *const EHTimerName = "write_exception";
+static const char *const EHTimerDescription = "DWARF Exception Writer";
+static const char *const CodeViewLineTablesGroupName = "linetables";
+static const char *const CodeViewLineTablesGroupDescription =
+  "CodeView Line Tables";
 
 STATISTIC(EmittedInsts, "Number of machine instrs printed");
 
 char AsmPrinter::ID = 0;
 
 typedef DenseMap<GCStrategy*, std::unique_ptr<GCMetadataPrinter>> gcp_map_type;
 static gcp_map_type &getGCMap(void *&P) {
   if (!P)
if (!M.getModuleInlineAsm().empty()) {
     OutStreamer->AddComment("End of file scope inline assembly");
     OutStreamer->AddBlankLine();
   }
 
   if (MAI->doesSupportDebugInformation()) {
     bool EmitCodeView = MMI->getModule()->getCodeViewFlag();
     if (EmitCodeView && TM.getTargetTriple().isKnownWindowsMSVCEnvironment()) {
       Handlers.push_back(HandlerInfo(new CodeViewDebug(this),
-                                     DbgTimerName,
-                                     CodeViewLineTablesGroupName));
+                                     DbgTimerName, DbgTimerDescription,
+                                     CodeViewLineTablesGroupName,
+                                     CodeViewLineTablesGroupDescription));
     }
     if (!EmitCodeView || MMI->getModule()->getDwarfVersion()) {
       DD = new DwarfDebug(this, &M);
       DD->beginModule();
-      Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName));
+      Handlers.push_back(HandlerInfo(DD, DbgTimerName, DbgTimerDescription,
+                                     DWARFGroupName, DWARFGroupDescription));
     }
   }
 
   EHStreamer *ES = nullptr;
   switch (MAI->getExceptionHandlingType()) {
   case ExceptionHandling::None:
     break;
   case ExceptionHandling::SjLj:
case ExceptionHandling::WinEH:
     case WinEH::EncodingType::X86:
     case WinEH::EncodingType::Itanium:
       ES = new WinException(this);
       break;
     }
     break;
   }
   if (ES)
-    Handlers.push_back(HandlerInfo(ES, EHTimerName, DWARFGroupName));
+    Handlers.push_back(HandlerInfo(ES, EHTimerName, EHTimerDescription,
+                                   DWARFGroupName, DWARFGroupDescription));
   return false;
 }
 
 static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
   if (!MAI.hasWeakDefCanBeHiddenDirective())
     return false;
 
   return canBeOmittedFromSymbolTable(GV);
void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
   uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
 
   // If the alignment is specified, we *must* obey it.  Overaligning a global
   // with a specified alignment is a prompt way to break globals emitted to
   // sections and expected to be contiguous (e.g. ObjC metadata).
   unsigned AlignLog = getGVAlignmentLog2(GV, DL);
 
   for (const HandlerInfo &HI : Handlers) {
-    NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
+    NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
+                       HI.TimerGroupName, HI.TimerGroupDescription,
+                       TimePassesIsEnabled);
     HI.Handler->setSymbolSize(GVSym, Size);
   }
 
   // Handle common symbols
   if (GVKind.isCommon()) {
     if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
     unsigned Align = 1 << AlignLog;
     if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
if (MAI->useAssignmentForEHBegin()) {
                                  MCSymbolRefExpr::create(CurPos, OutContext));
     } else {
       OutStreamer->EmitLabel(CurrentFnBegin);
     }
   }
 
   // Emit pre-function debug and/or EH information.
   for (const HandlerInfo &HI : Handlers) {
-    NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
+    NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
+                       HI.TimerGroupDescription, TimePassesIsEnabled);
     HI.Handler->beginFunction(MF);
   }
 
   // Emit the prologue data.
   if (F->hasPrologueData())
     EmitGlobalConstant(F->getParent()->getDataLayout(), F->getPrologueData());
 }
 
for (auto &MI : MBB) {
       if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
           !MI.isDebugValue()) {
         HasAnyRealCode = true;
         ++EmittedInsts;
       }
 
       if (ShouldPrintDebugScopes) {
         for (const HandlerInfo &HI : Handlers) {
-          NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
+          NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
+                             HI.TimerGroupName, HI.TimerGroupDescription,
                              TimePassesIsEnabled);
           HI.Handler->beginInstruction(&MI);
         }
       }
 
       if (isVerbose())
         emitComments(MI, OutStreamer->GetCommentOS());
 
for (auto &MI : MBB) {
         break;
       default:
         EmitInstruction(&MI);
         break;
       }
 
       if (ShouldPrintDebugScopes) {
         for (const HandlerInfo &HI : Handlers) {
-          NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
+          NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
+                             HI.TimerGroupName, HI.TimerGroupDescription,
                              TimePassesIsEnabled);
           HI.Handler->endInstruction();
         }
       }
     }
 
     EmitBasicBlockEnd(MBB);
   }
if (MAI->hasDotTypeDotSizeDirective()) {
     const MCExpr *SizeExp = MCBinaryExpr::createSub(
         MCSymbolRefExpr::create(CurrentFnEnd, OutContext),
         MCSymbolRefExpr::create(CurrentFnSymForSize, OutContext), OutContext);
     if (auto Sym = dyn_cast<MCSymbolELF>(CurrentFnSym))
       OutStreamer->emitELFSize(Sym, SizeExp);
   }
 
   for (const HandlerInfo &HI : Handlers) {
-    NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
+    NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
+                       HI.TimerGroupDescription, TimePassesIsEnabled);
     HI.Handler->markFunctionEnd();
   }
 
   // Print out jump tables referenced by the function.
   EmitJumpTableInfo();
 
   // Emit post-function debug and/or EH information.
   for (const HandlerInfo &HI : Handlers) {
-    NamedRegionTimer T(HI.TimerName, HI.TimerGroupName, TimePassesIsEnabled);
+    NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
+                       HI.TimerGroupDescription, TimePassesIsEnabled);
     HI.Handler->endFunction(MF);
   }
   MMI->EndFunction();
 
   OutStreamer->AddBlankLine();
 }
 
 /// \brief Compute the number of Global Variables that uses a Constant.
if (!Stubs.empty()) {
         OutStreamer->EmitSymbolValue(Stub.second.getPointer(),
                                      DL.getPointerSize());
       }
     }
   }
 
   // Finalize debug and EH information.
   for (const HandlerInfo &HI : Handlers) {
-    NamedRegionTimer T(HI.TimerName, HI.TimerGroupName,
-                       TimePassesIsEnabled);
+    NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
+                       HI.TimerGroupDescription, TimePassesIsEnabled);
     HI.Handler->endModule();
     delete HI.Handler;
   }
   Handlers.clear();
   DD = nullptr;
 
   // If the target wants to know about weak references, print them all.
   if (MAI->getWeakRefDirective()) {

lib/CodeGen/AsmPrinter/DwarfDebug.cpp

DwarfLinkageNames("dwarf-linkage-names", cl::Hidden,
                       cl::desc("Which DWARF linkage-name attributes to emit."),
                       cl::values(clEnumValN(DefaultLinkageNames, "Default",
                                             "Default for platform"),
                                  clEnumValN(AllLinkageNames, "All", "All"),
                                  clEnumValN(AbstractLinkageNames, "Abstract",
                                             "Abstract subprograms")),
                       cl::init(DefaultLinkageNames));
 
-static const char *const DWARFGroupName = "DWARF Emission";
-static const char *const DbgTimerName = "DWARF Debug Writer";
+static const char *const DWARFGroupName = "dwarf";
+static const char *const DWARFGroupDescription = "DWARF Emission";
+static const char *const DbgTimerName = "writer";
+static const char *const DbgTimerDescription = "DWARF Debug Writer";
 
 void DebugLocDwarfExpression::EmitOp(uint8_t Op, const char *Comment) {
   BS.EmitInt8(
       Op, Comment ? Twine(Comment) + " " + dwarf::OperationEncodingString(Op)
                   : dwarf::OperationEncodingString(Op));
 }
 
 void DebugLocDwarfExpression::EmitSigned(int64_t Value) {
void DwarfDebug::constructAndAddImportedEntityDIE(DwarfCompileUnit &TheCU,
   if (DIE *D = TheCU.getOrCreateContextDIE(N->getScope()))
     D->addChild(TheCU.constructImportedEntityDIE(N));
 }
 
 // Emit all Dwarf sections that should come prior to the content. Create
 // global DIEs and emit initial debug info sections. This is invoked by
 // the target AsmPrinter.
 void DwarfDebug::beginModule() {
-  NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled);
+  NamedRegionTimer T(DbgTimerName, DbgTimerDescription, DWARFGroupName,
+                     DWARFGroupDescription, TimePassesIsEnabled);
   if (DisableDebugInfoPrinting)
     return;
 
   const Module *M = MMI->getModule();
 
   unsigned NumDebugCUs = std::distance(M->debug_compile_units_begin(),
                                        M->debug_compile_units_end());
   // Tell MMI whether we have debug info.

lib/CodeGen/RegAllocBase.h

protected:
   // Each call must guarantee forward progess by returning an available PhysReg
   // or new set of split live virtual registers. It is up to the splitter to
   // converge quickly toward fully spilled live ranges.
   virtual unsigned selectOrSplit(LiveInterval &VirtReg,
                                  SmallVectorImpl<unsigned> &splitLVRs) = 0;
 
   // Use this group name for NamedRegionTimer.
   static const char TimerGroupName[];
+  static const char TimerGroupDescription[];
 
   /// Method called when the allocator is about to remove a LiveInterval.
   virtual void aboutToRemoveInterval(LiveInterval &LI) {}
 
 public:
   /// VerifyEnabled - True when -verify-regalloc is given.
   static bool VerifyEnabled;
 
 private:
   void seedLiveRegs();
 };
 
 } // end namespace llvm
 
 #endif

lib/CodeGen/RegAllocBase.cpp

 STATISTIC(NumNewQueued    , "Number of new live ranges queued");
 
 // Temporary verification option until we can put verification inside
 // MachineVerifier.
 static cl::opt<bool, true>
 VerifyRegAlloc("verify-regalloc", cl::location(RegAllocBase::VerifyEnabled),
                cl::desc("Verify during register allocation"));
 
-const char RegAllocBase::TimerGroupName[] = "Register Allocation";
+const char RegAllocBase::TimerGroupName[] = "regalloc";
+const char RegAllocBase::TimerGroupDescription[] = "Register Allocation";
 bool RegAllocBase::VerifyEnabled = false;
 
 //===----------------------------------------------------------------------===//
 //                         RegAllocBase Implementation
 //===----------------------------------------------------------------------===//
 
 // Pin the vtable to this file.
 void RegAllocBase::anchor() {}
void RegAllocBase::init(VirtRegMap &vrm,
   MRI->freezeReservedRegs(vrm.getMachineFunction());
   RegClassInfo.runOnMachineFunction(vrm.getMachineFunction());
 }
 
 // Visit all the live registers. If they are already assigned to a physical
 // register, unify them with the corresponding LiveIntervalUnion, otherwise push
 // them on the priority queue for later assignment.
 void RegAllocBase::seedLiveRegs() {
-  NamedRegionTimer T("Seed Live Regs", TimerGroupName, TimePassesIsEnabled);
+  NamedRegionTimer T("seed", "Seed Live Regs", TimerGroupName,
+                     TimerGroupDescription, TimePassesIsEnabled);
   for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
     unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
     if (MRI->reg_nodbg_empty(Reg))
       continue;
     enqueue(&LIS->getInterval(Reg));
   }
 }
 

lib/CodeGen/RegAllocGreedy.cpp

 /// tryEvict - Try to evict all interferences for a physreg.
 /// @param  VirtReg Currently unassigned virtual register.
 /// @param  Order   Physregs to try.
 /// @return         Physreg to assign VirtReg, or 0.
 unsigned RAGreedy::tryEvict(LiveInterval &VirtReg,
                             AllocationOrder &Order,
                             SmallVectorImpl<unsigned> &NewVRegs,
                             unsigned CostPerUseLimit) {
-  NamedRegionTimer T("Evict", TimerGroupName, TimePassesIsEnabled);
+  NamedRegionTimer T("evict", "Evict", TimerGroupName, TimerGroupDescription,
+                     TimePassesIsEnabled);
 
   // Keep track of the cheapest interference seen so far.
   EvictionCost BestCost;
   BestCost.setMax();
   unsigned BestPhys = 0;
   unsigned OrderLimit = Order.getOrder().size();
 
   // When we are just looking for a reduced cost per use, don't break any

 unsigned RAGreedy::trySplit(LiveInterval &VirtReg, AllocationOrder &Order,
                             SmallVectorImpl<unsigned>&NewVRegs) {
   // Ranges must be Split2 or less.
   if (getStage(VirtReg) >= RS_Spill)
     return 0;
 
   // Local intervals are handled separately.
   if (LIS->intervalIsInOneMBB(VirtReg)) {
-    NamedRegionTimer T("Local Splitting", TimerGroupName, TimePassesIsEnabled);
+    NamedRegionTimer T("local_split", "Local Splitting", TimerGroupName,
+                       TimerGroupDescription, TimePassesIsEnabled);
     SA->analyze(&VirtReg);
     unsigned PhysReg = tryLocalSplit(VirtReg, Order, NewVRegs);
     if (PhysReg || !NewVRegs.empty())
       return PhysReg;
     return tryInstructionSplit(VirtReg, Order, NewVRegs);
   }
 
-  NamedRegionTimer T("Global Splitting", TimerGroupName, TimePassesIsEnabled);
+  NamedRegionTimer T("global_split", "Global Splitting", TimerGroupName,
+                     TimerGroupDescription, TimePassesIsEnabled);
 
   SA->analyze(&VirtReg);
 
   // FIXME: SplitAnalysis may repair broken live ranges coming from the
   // coalescer. That may cause the range to become allocatable which means that
   // tryRegionSplit won't be making progress. This check should be replaced with
   // an assertion when the coalescer is fixed.
   if (SA->didRepairRange()) {
if (EnableDeferredSpilling && getStage(VirtReg) < RS_Memory) {
     // TODO: This is experimental and in particular, we do not model
     // the live range splitting done by spilling correctly.
     // We would need a deep integration with the spiller to do the
     // right thing here. Anyway, that is still good for early testing.
     setStage(VirtReg, RS_Memory);
     DEBUG(dbgs() << "Do as if this register is in memory\n");
     NewVRegs.push_back(VirtReg.reg);
   } else {
-    NamedRegionTimer T("Spiller", TimerGroupName, TimePassesIsEnabled);
+    NamedRegionTimer T("spill", "Spiller", TimerGroupName,
+                       TimerGroupDescription, TimePassesIsEnabled);
     LiveRangeEdit LRE(&VirtReg, NewVRegs, *MF, *LIS, VRM, this, &DeadRemats);
     spiller().spill(LRE);
     setStage(NewVRegs.begin(), NewVRegs.end(), RS_Done);
 
     if (VerifyEnabled)
       MF->verify(this, "After spilling");
   }
 

lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp

do {
 
     unsigned NumSignBits = CurDAG->ComputeNumSignBits(Src);
     CurDAG->computeKnownBits(Src, KnownZero, KnownOne);
     FuncInfo->AddLiveOutRegInfo(DestReg, NumSignBits, KnownZero, KnownOne);
   } while (!Worklist.empty());
 }
 
 void SelectionDAGISel::CodeGenAndEmitDAG() {
-  std::string GroupName;
-  if (TimePassesIsEnabled)
-    GroupName = "Instruction Selection and Scheduling";
+  StringRef GroupName = "sdag";
+  StringRef GroupDescription = "Instruction Selection and Scheduling";
   std::string BlockName;
   int BlockNumber = -1;
   (void)BlockNumber;
   bool MatchFilterBB = false; (void)MatchFilterBB;
 #ifndef NDEBUG
   MatchFilterBB = (FilterDAGBasicBlockName.empty() ||
                    FilterDAGBasicBlockName ==
                        FuncInfo->MBB->getBasicBlock()->getName().str());
#endif
   DEBUG(dbgs() << "Initial selection DAG: BB#" << BlockNumber
         << " '" << BlockName << "'\n"; CurDAG->dump());
 
   if (ViewDAGCombine1 && MatchFilterBB)
     CurDAG->viewGraph("dag-combine1 input for " + BlockName);
 
   // Run the DAG combiner in pre-legalize mode.
   {
-    NamedRegionTimer T("DAG Combining 1", GroupName, TimePassesIsEnabled);
+    NamedRegionTimer T("combine1", "DAG Combining 1", GroupName,
+                       GroupDescription, TimePassesIsEnabled);
     CurDAG->Combine(BeforeLegalizeTypes, *AA, OptLevel);
   }
 
   DEBUG(dbgs() << "Optimized lowered selection DAG: BB#" << BlockNumber
         << " '" << BlockName << "'\n"; CurDAG->dump());
 
   // Second step, hack on the DAG until it only uses operations and types that
   // the target supports.
   if (ViewLegalizeTypesDAGs && MatchFilterBB)
     CurDAG->viewGraph("legalize-types input for " + BlockName);
 
   bool Changed;
   {
-    NamedRegionTimer T("Type Legalization", GroupName, TimePassesIsEnabled);
+    NamedRegionTimer T("legalize_types", "Type Legalization", GroupName,
+                       GroupDescription, TimePassesIsEnabled);
     Changed = CurDAG->LegalizeTypes();
   }
 
   DEBUG(dbgs() << "Type-legalized selection DAG: BB#" << BlockNumber
         << " '" << BlockName << "'\n"; CurDAG->dump());
 
   CurDAG->NewNodesMustHaveLegalTypes = true;
 
   if (Changed) {
     if (ViewDAGCombineLT && MatchFilterBB)
       CurDAG->viewGraph("dag-combine-lt input for " + BlockName);
 
     // Run the DAG combiner in post-type-legalize mode.
     {
-      NamedRegionTimer T("DAG Combining after legalize types", GroupName,
-                         TimePassesIsEnabled);
+      NamedRegionTimer T("combine_lt", "DAG Combining after legalize types",
+                         GroupName, GroupDescription, TimePassesIsEnabled);
       CurDAG->Combine(AfterLegalizeTypes, *AA, OptLevel);
     }
 
     DEBUG(dbgs() << "Optimized type-legalized selection DAG: BB#" << BlockNumber
           << " '" << BlockName << "'\n"; CurDAG->dump());
 
   }
 
   {
-    NamedRegionTimer T("Vector Legalization", GroupName, TimePassesIsEnabled);
+    NamedRegionTimer T("legalize_vec", "Vector Legalization", GroupName,
+                       GroupDescription, TimePassesIsEnabled);
     Changed = CurDAG->LegalizeVectors();
   }
 
   if (Changed) {
     {
-      NamedRegionTimer T("Type Legalization 2", GroupName, TimePassesIsEnabled);
+      NamedRegionTimer T("legalize_types2", "Type Legalization 2", GroupName,
+                         GroupDescription, TimePassesIsEnabled);
       CurDAG->LegalizeTypes();
     }
 
     if (ViewDAGCombineLT && MatchFilterBB)
       CurDAG->viewGraph("dag-combine-lv input for " + BlockName);
 
     // Run the DAG combiner in post-type-legalize mode.
     {
-      NamedRegionTimer T("DAG Combining after legalize vectors", GroupName,
-                         TimePassesIsEnabled);
+      NamedRegionTimer T("combine_lv", "DAG Combining after legalize vectors",
+                         GroupName, GroupDescription, TimePassesIsEnabled);
       CurDAG->Combine(AfterLegalizeVectorOps, *AA, OptLevel);
     }
 
     DEBUG(dbgs() << "Optimized vector-legalized selection DAG: BB#"
           << BlockNumber << " '" << BlockName << "'\n"; CurDAG->dump());
   }
 
   if (ViewLegalizeDAGs && MatchFilterBB)
     CurDAG->viewGraph("legalize input for " + BlockName);
 
   {
-    NamedRegionTimer T("DAG Legalization", GroupName, TimePassesIsEnabled);
+    NamedRegionTimer T("legalize", "DAG Legalization", GroupName,
+                       GroupDescription, TimePassesIsEnabled);
     CurDAG->Legalize();
   }
 
   DEBUG(dbgs() << "Legalized selection DAG: BB#" << BlockNumber
         << " '" << BlockName << "'\n"; CurDAG->dump());
 
   if (ViewDAGCombine2 && MatchFilterBB)
     CurDAG->viewGraph("dag-combine2 input for " + BlockName);
 
   // Run the DAG combiner in post-legalize mode.
   {
-    NamedRegionTimer T("DAG Combining 2", GroupName, TimePassesIsEnabled);
+    NamedRegionTimer T("combine2", "DAG Combining 2", GroupName,
+                       GroupDescription, TimePassesIsEnabled);
     CurDAG->Combine(AfterLegalizeDAG, *AA, OptLevel);
   }
 
   DEBUG(dbgs() << "Optimized legalized selection DAG: BB#" << BlockNumber
         << " '" << BlockName << "'\n"; CurDAG->dump());
 
   if (OptLevel != CodeGenOpt::None)
     ComputeLiveOutVRegInfo();
 
   if (ViewISelDAGs && MatchFilterBB)
     CurDAG->viewGraph("isel input for " + BlockName);
 
   // Third, instruction select all of the operations to machine code, adding the
   // code to the MachineBasicBlock.
   {
-    NamedRegionTimer T("Instruction Selection", GroupName, TimePassesIsEnabled);
+    NamedRegionTimer T("isel", "Instruction Selection", GroupName,
+                       GroupDescription, TimePassesIsEnabled);
     DoInstructionSelection();
   }
 
   DEBUG(dbgs() << "Selected selection DAG: BB#" << BlockNumber
         << " '" << BlockName << "'\n"; CurDAG->dump());
 
   if (ViewSchedDAGs && MatchFilterBB)
     CurDAG->viewGraph("scheduler input for " + BlockName);
 
   // Schedule machine code.
   ScheduleDAGSDNodes *Scheduler = CreateScheduler();
   {
-    NamedRegionTimer T("Instruction Scheduling", GroupName,
-                       TimePassesIsEnabled);
+    NamedRegionTimer T("sched", "Instruction Scheduling", GroupName,
+                       GroupDescription, TimePassesIsEnabled);
     Scheduler->Run(CurDAG, FuncInfo->MBB);
   }
 
   if (ViewSUnitDAGs && MatchFilterBB)
     Scheduler->viewGraph();
 
   // Emit machine code to BB.  This can change 'BB' to the last block being
   // inserted into.
   MachineBasicBlock *FirstMBB = FuncInfo->MBB, *LastMBB;
   {
-    NamedRegionTimer T("Instruction Creation", GroupName, TimePassesIsEnabled);
+    NamedRegionTimer T("emit", "Instruction Creation", GroupName,
+                       GroupDescription, TimePassesIsEnabled);
 
     // FuncInfo->InsertPt is passed by reference and set to the end of the
     // scheduled instructions.
     LastMBB = FuncInfo->MBB = Scheduler->EmitSchedule(FuncInfo->InsertPt);
   }
 
   // If the block was split, make sure we update any references that are used to
   // update PHI nodes later on.
   if (FirstMBB != LastMBB)
     SDB->UpdateSplitBlock(FirstMBB, LastMBB);
 
   // Free the scheduler state.
   {
-    NamedRegionTimer T("Instruction Scheduling Cleanup", GroupName,
-                       TimePassesIsEnabled);
+    NamedRegionTimer T("cleanup", "Instruction Scheduling Cleanup", GroupName,
+                       GroupDescription, TimePassesIsEnabled);
     delete Scheduler;
   }
 
   // Free the SelectionDAG state, now that we're finished with it.
   CurDAG->clear();
 }
 
 namespace {

lib/IR/LegacyPassManager.cpp

 
 static ManagedStatic<sys::SmartMutex<true> > TimingInfoMutex;
 
 class TimingInfo {
   DenseMap<Pass*, Timer*> TimingData;
   TimerGroup TG;
 public:
   // Use 'create' member to get this.
-  TimingInfo() : TG("... Pass execution timing report ...") {}
+  TimingInfo() : TG("pass", "... Pass execution timing report ...") {}
 
   // TimingDtor - Print out information about timing information
   ~TimingInfo() {
     // Delete all of the timers, which accumulate their info into the
     // TimerGroup.
     for (auto &I : TimingData)
       delete I.second;
     // TimerGroup is deleted next, printing the report.
   }
 
   // createTheTimeInfo - This method either initializes the TheTimeInfo pointer
   // to a non-null value (if the -time-passes option is enabled) or it leaves it
   // null.  It may be called multiple times.
   static void createTheTimeInfo();
 
   /// getPassTimer - Return the timer for the specified pass if it exists.
   Timer *getPassTimer(Pass *P) {
     if (P->getAsPMDataManager())
       return nullptr;
 
     sys::SmartScopedLock<true> Lock(*TimingInfoMutex);
     Timer *&T = TimingData[P];
-    if (!T)
-      T = new Timer(P->getPassName(), TG);
+    if (!T) {
+      StringRef PassName = P->getPassName();
+      T = new Timer(PassName, PassName, TG);
+    }
     return T;
   }
 };
 
 } // End of anon namespace
 
 static TimingInfo *TheTimeInfo;
 

lib/IRReader/IRReader.cpp

 #include <system_error>
 
 using namespace llvm;
 
 namespace llvm {
   extern bool TimePassesIsEnabled;
 }
 
-static const char *const TimeIRParsingGroupName = "LLVM IR Parsing";
-static const char *const TimeIRParsingName = "Parse IR";
+static const char *const TimeIRParsingGroupName = "irparse";
+static const char *const TimeIRParsingGroupDescription = "LLVM IR Parsing";
+static const char *const TimeIRParsingName = "parse";
+static const char *const TimeIRParsingDescription = "Parse IR";
 
 static std::unique_ptr<Module>
 getLazyIRModule(std::unique_ptr<MemoryBuffer> Buffer, SMDiagnostic &Err,
                 LLVMContext &Context, bool ShouldLazyLoadMetadata) {
   if (isBitcode((const unsigned char *)Buffer->getBufferStart(),
                 (const unsigned char *)Buffer->getBufferEnd())) {
     ErrorOr<std::unique_ptr<Module>> ModuleOrErr = getLazyBitcodeModule(
         std::move(Buffer), Context, ShouldLazyLoadMetadata);
std::unique_ptr<Module> llvm::getLazyIRFileModule(StringRef Filename,
   }
 
   return getLazyIRModule(std::move(FileOrErr.get()), Err, Context,
                          ShouldLazyLoadMetadata);
 }
 
 std::unique_ptr<Module> llvm::parseIR(MemoryBufferRef Buffer, SMDiagnostic &Err,
                                       LLVMContext &Context) {
-  NamedRegionTimer T(TimeIRParsingName, TimeIRParsingGroupName,
+  NamedRegionTimer T(TimeIRParsingName, TimeIRParsingDescription,
+                     TimeIRParsingGroupName, TimeIRParsingGroupDescription,
                      TimePassesIsEnabled);
   if (isBitcode((const unsigned char *)Buffer.getBufferStart(),
                 (const unsigned char *)Buffer.getBufferEnd())) {
     ErrorOr<std::unique_ptr<Module>> ModuleOrErr =
         parseBitcodeFile(Buffer, Context);
     if (std::error_code EC = ModuleOrErr.getError()) {
       Err = SMDiagnostic(Buffer.getBufferIdentifier(), SourceMgr::DK_Error,
                          EC.message());

lib/Support/Timer.cpp

 static TimerGroup *getDefaultTimerGroup() {
   TimerGroup *tmp = DefaultTimerGroup;
   sys::MemoryFence();
   if (tmp) return tmp;
 
   sys::SmartScopedLock<true> Lock(*TimerLock);
   tmp = DefaultTimerGroup;
   if (!tmp) {
-    tmp = new TimerGroup("Miscellaneous Ungrouped Timers");
+    tmp = new TimerGroup("Misc", "Miscellaneous Ungrouped Timers");
     sys::MemoryFence();
     DefaultTimerGroup = tmp;
   }
 
   return tmp;
 }
 
 //===----------------------------------------------------------------------===//
 // Timer Implementation
 //===----------------------------------------------------------------------===//
 
-void Timer::init(StringRef N) {
-  init(N, *getDefaultTimerGroup());
+void Timer::init(StringRef Name, StringRef Description) {
+  init(Name, Description, *getDefaultTimerGroup());
 }
 
-void Timer::init(StringRef N, TimerGroup &tg) {
+void Timer::init(StringRef Name, StringRef Description, TimerGroup &tg) {
   assert(!TG && "Timer already initialized");
-  Name.assign(N.begin(), N.end());
+  this->Name.assign(Name.begin(), Name.end());
+  this->Description.assign(Description.begin(), Description.end());
   Running = Triggered = false;
   TG = &tg;
   TG->addTimer(*this);
 }
 
 Timer::~Timer() {
   if (!TG) return;  // Never initialized, or already cleared.
   TG->removeTimer(*this);
class Name2PairMap {
   StringMap<std::pair<TimerGroup*, Name2TimerMap> > Map;
 public:
   ~Name2PairMap() {
     for (StringMap<std::pair<TimerGroup*, Name2TimerMap> >::iterator
          I = Map.begin(), E = Map.end(); I != E; ++I)
       delete I->second.first;
   }
 
-  Timer &get(StringRef Name, StringRef GroupName) {
+  Timer &get(StringRef Name, StringRef Description, StringRef GroupName,
+             StringRef GroupDescription) {
     sys::SmartScopedLock<true> L(*TimerLock);
 
     std::pair<TimerGroup*, Name2TimerMap> &GroupEntry = Map[GroupName];
 
     if (!GroupEntry.first)
-      GroupEntry.first = new TimerGroup(GroupName);
+      GroupEntry.first = new TimerGroup(GroupName, GroupDescription);
 
     Timer &T = GroupEntry.second[Name];
     if (!T.isInitialized())
-      T.init(Name, *GroupEntry.first);
+      T.init(Name, Description, *GroupEntry.first);
     return T;
   }
 };
 
 }
 
-static ManagedStatic<Name2TimerMap> NamedTimers;
 static ManagedStatic<Name2PairMap> NamedGroupedTimers;
 
-static Timer &getNamedRegionTimer(StringRef Name) {
-  sys::SmartScopedLock<true> L(*TimerLock);
-
-  Timer &T = (*NamedTimers)[Name];
-  if (!T.isInitialized())
-    T.init(Name);
-  return T;
-}
-
-NamedRegionTimer::NamedRegionTimer(StringRef Name,
-                                   bool Enabled)
-  : TimeRegion(!Enabled ? nullptr : &getNamedRegionTimer(Name)) {}
-
-NamedRegionTimer::NamedRegionTimer(StringRef Name, StringRef GroupName,
-                                   bool Enabled)
-  : TimeRegion(!Enabled ? nullptr : &NamedGroupedTimers->get(Name, GroupName)){}
+NamedRegionTimer::NamedRegionTimer(StringRef Name, StringRef Description,
+                                   StringRef GroupName,
+                                   StringRef GroupDescription, bool Enabled)
+  : TimeRegion(!Enabled ? nullptr
+                 : &NamedGroupedTimers->get(Name, Description, GroupName,
+                                            GroupDescription)) {}
 
 //===----------------------------------------------------------------------===//
 //   TimerGroup Implementation
 //===----------------------------------------------------------------------===//
 
 /// This is the global list of TimerGroups, maintained by the TimerGroup
 /// ctor/dtor and is protected by the TimerLock lock.
 static TimerGroup *TimerGroupList = nullptr;
 
-TimerGroup::TimerGroup(StringRef name)
-  : Name(name.begin(), name.end()) {
-
+TimerGroup::TimerGroup(StringRef Name, StringRef Description)
+  : Name(Name.begin(), Name.end()),
+    Description(Description.begin(), Description.end()) {
   // Add the group to TimerGroupList.
   sys::SmartScopedLock<true> L(*TimerLock);
   if (TimerGroupList)
     TimerGroupList->Prev = &Next;
   Next = TimerGroupList;
   Prev = &TimerGroupList;
   TimerGroupList = this;
 }

 }
 
 
 void TimerGroup::removeTimer(Timer &T) {
   sys::SmartScopedLock<true> L(*TimerLock);
 
   // If the timer was started, move its data to TimersToPrint.
   if (T.hasTriggered())
-    TimersToPrint.emplace_back(T.Time, T.Name);
+    TimersToPrint.emplace_back(T.Time, T.Description);
 
   T.TG = nullptr;
 
   // Unlink the timer from our list.
   *T.Prev = T.Next;
   if (T.Next)
     T.Next->Prev = T.Prev;
 
void TimerGroup::PrintQueuedTimers(raw_ostream &OS) {
 
   TimeRecord Total;
   for (auto &RecordNamePair : TimersToPrint)
     Total += RecordNamePair.first;
 
   // Print out timing header.
   OS << "===" << std::string(73, '-') << "===\n";
   // Figure out how many spaces to indent TimerGroup name.
-  unsigned Padding = (80-Name.length())/2;
+  unsigned Padding = (80-Description.length())/2;
   if (Padding > 80) Padding = 0;         // Don't allow "negative" numbers
-  OS.indent(Padding) << Name << '\n';
+  OS.indent(Padding) << Description << '\n';
   OS << "===" << std::string(73, '-') << "===\n";
 
   // If this is not an collection of ungrouped times, print the total time.
   // Ungrouped timers don't really make sense to add up.  We still print the
   // TOTAL line to make the percentages make sense.
   if (this != DefaultTimerGroup)
     OS << format("  Total Execution Time: %5.4f seconds (%5.4f wall clock)\n",
                  Total.getProcessTime(), Total.getWallTime());

 
 void TimerGroup::print(raw_ostream &OS) {
   sys::SmartScopedLock<true> L(*TimerLock);
 
   // See if any of our timers were started, if so add them to TimersToPrint and
   // reset them.
   for (Timer *T = FirstTimer; T; T = T->Next) {
     if (!T->hasTriggered()) continue;
-    TimersToPrint.emplace_back(T->Time, T->Name);
+    TimersToPrint.emplace_back(T->Time, T->Description);
 
     // Clear out the time.
     T->clear();
   }
 
   // If any timers were started, print the group.
   if (!TimersToPrint.empty())
     PrintQueuedTimers(OS);
 }
 
 void TimerGroup::printAll(raw_ostream &OS) {
   sys::SmartScopedLock<true> L(*TimerLock);
 
   for (TimerGroup *TG = TimerGroupList; TG; TG = TG->Next)
     TG->print(OS);
 }

utils/yaml-bench/YAMLBench.cpp

for (yaml::document_iterator di = stream.begin(), de = stream.end(); di != de;
     if (n)
       dumpNode(n);
     else
       break;
     outs() << "\n...\n";
   }
 }
 
-static void benchmark( llvm::TimerGroup &Group
-                     , llvm::StringRef Name
-                     , llvm::StringRef JSONText) {
-  llvm::Timer BaseLine((Name + ": Loop").str(), Group);
+static void benchmark(llvm::TimerGroup &Group, llvm::StringRef Name,
+                      llvm::StringRef Description, llvm::StringRef JSONText) {
+  llvm::Timer BaseLine((Name + ".loop").str(), (Description + ": Loop").str(),
+                       Group);
   BaseLine.startTimer();
   char C = 0;
   for (llvm::StringRef::iterator I = JSONText.begin(),
                                  E = JSONText.end();
        I != E; ++I) { C += *I; }
   BaseLine.stopTimer();
   volatile char DontOptimizeOut = C; (void)DontOptimizeOut;
 
-  llvm::Timer Tokenizing((Name + ": Tokenizing").str(), Group);
+  llvm::Timer Tokenizing((Name + ".tokenizing").str(),
+                         (Description + ": Tokenizing").str(), Group);
   Tokenizing.startTimer();
   {
     yaml::scanTokens(JSONText);
   }
   Tokenizing.stopTimer();
 
-  llvm::Timer Parsing((Name + ": Parsing").str(), Group);
+  llvm::Timer Parsing((Name + ".parsing").str(),
+                      (Description + ": Parsing").str(), Group);
   Parsing.startTimer();
   {
     llvm::SourceMgr SM;
     llvm::yaml::Stream stream(JSONText, SM);
     stream.skip();
   }
   Parsing.stopTimer();
 }
if (DumpCanonical) {
       yaml::Stream stream(Buf.getBuffer(), sm, ShowColors);
       dumpStream(stream);
       if (stream.failed())
         return 1;
     }
   }
 
   if (Verify) {
-    llvm::TimerGroup Group("YAML parser benchmark");
-    benchmark(Group, "Fast", createJSONText(10, 500));
+    llvm::TimerGroup Group("yaml", "YAML parser benchmark");
+    benchmark(Group, "Fast", "Fast", createJSONText(10, 500));
   } else if (!DumpCanonical && !DumpTokens) {
-    llvm::TimerGroup Group("YAML parser benchmark");
-    benchmark(Group, "Small Values", createJSONText(MemoryLimitMB, 5));
-    benchmark(Group, "Medium Values", createJSONText(MemoryLimitMB, 500));
-    benchmark(Group, "Large Values", createJSONText(MemoryLimitMB, 50000));
+    llvm::TimerGroup Group("yaml", "YAML parser benchmark");
+    benchmark(Group, "Small", "Small Values", createJSONText(MemoryLimitMB, 5));
+    benchmark(Group, "Medium", "Medium Values",
+              createJSONText(MemoryLimitMB, 500));
+    benchmark(Group, "Large", "Large Values",
+              createJSONText(MemoryLimitMB, 50000));
   }
 
   return 0;
 }