Subzero: Add a few performance measurement tools.

src/IceRegAlloc.cpp

 //===- subzero/src/IceRegAlloc.cpp - Linear-scan implementation -----------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the LinearScan class, which performs the
@@ skipping 46 matching lines @@
 // Constraints" by Hanspeter Mössenböck and Michael Pfeiffer,
 // ftp://ftp.ssw.uni-linz.ac.at/pub/Papers/Moe02.PDF .  This
 // implementation is modified to take affinity into account and allow
 // two interfering variables to share the same register in certain
 // cases.
 //
 // Requires running Cfg::liveness(Liveness_Intervals) in
 // preparation.  Results are assigned to Variable::RegNum for each
 // Variable.
 void LinearScan::scan(const llvm::SmallBitVector &RegMaskFull) {
-  static TimerIdT IDscan = GlobalContext::getTimerID("linearScan");
-  TimerMarker T(IDscan, Func->getContext());
+  TimerMarker T(TimerStack::TT_linearScan, Func);
   assert(RegMaskFull.any()); // Sanity check
   Unhandled.clear();
   UnhandledPrecolored.clear();
   Handled.clear();
   Inactive.clear();
   Active.clear();
   Ostream &Str = Func->getContext()->getStrDump();
   bool Verbose = Func->getContext()->isVerbose(IceV_LinearScan);
   Func->resetCurrentNode();
   VariablesMetadata *VMetadata = Func->getVMetadata();
 
   // Gather the live ranges of all variables and add them to the
   // Unhandled set.  TODO: Unhandled is a set<> which is based on a
   // balanced binary tree, so inserting live ranges for N variables is
   // O(N log N) complexity.  N may be proportional to the number of
   // instructions, thanks to temporary generation during lowering.  As
   // a result, it may be useful to design a better data structure for
   // storing Func->getVariables().
   const VarList &Vars = Func->getVariables();
   {
-    static TimerIdT IDinitUnhandled =
-        GlobalContext::getTimerID("initUnhandled");
-    TimerMarker T(IDinitUnhandled, Func->getContext());
+    TimerMarker T(TimerStack::TT_initUnhandled, Func);
     for (Variable *Var : Vars) {
       // Explicitly don't consider zero-weight variables, which are
       // meant to be spill slots.
       if (Var->getWeight() == RegWeight::Zero)
         continue;
       // Don't bother if the variable has a null live range, which means
       // it was never referenced.
       if (Var->getLiveRange().isEmpty())
         continue;
       LiveRangeWrapper R(Var);
@@ skipping 448 matching lines @@
     Str << "\n";
   }
   Str << "++++++ Inactive:\n";
   for (const LiveRangeWrapper &Item : Inactive) {
     Item.dump(Func);
     Str << "\n";
   }
 }
 
 } // end of namespace Ice