Subzero: Add a few performance measurement tools.

src/IceTargetLowering.cpp

 //===- subzero/src/IceTargetLowering.cpp - Basic lowering 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 skeleton of the TargetLowering class,
@@ skipping 211 matching lines @@
 
   Context.advanceCur();
   Context.advanceNext();
 }
 
 // Drives register allocation, allowing all physical registers (except
 // perhaps for the frame pointer) to be allocated.  This set of
 // registers could potentially be parameterized if we want to restrict
 // registers e.g. for performance testing.
 void TargetLowering::regAlloc() {
-  static TimerIdT IDregAlloc = GlobalContext::getTimerID("regAlloc");
-  TimerMarker T(IDregAlloc, Ctx);
+  TimerMarker T(TimerStack::TT_regAlloc, Func);
   LinearScan LinearScan(Func);
   RegSetMask RegInclude = RegSet_None;
   RegSetMask RegExclude = RegSet_None;
   RegInclude |= RegSet_CallerSave;
   RegInclude |= RegSet_CalleeSave;
   if (hasFramePointer())
     RegExclude |= RegSet_FramePointer;
   llvm::SmallBitVector RegMask = getRegisterSet(RegInclude, RegExclude);
   LinearScan.scan(RegMask);
 }
@@ skipping 13 matching lines @@
   if (Target == Target_ARM64)
     return IceTargetGlobalInitARM64::create(Ctx);
 #endif
   llvm_unreachable("Unsupported target");
   return NULL;
 }
 
 TargetGlobalInitLowering::~TargetGlobalInitLowering() {}
 
 } // end of namespace Ice