Subzero: Add a few performance measurement tools.

src/IceGlobalContext.cpp

Index: src/IceGlobalContext.cpp
diff --git a/src/IceGlobalContext.cpp b/src/IceGlobalContext.cpp
index 7ea7e5dd02d10eaa64310926fb54b3cc9d3d4efc..4a7b6b576a37616050be0cb0f5793598aa6f90ff 100644
--- a/src/IceGlobalContext.cpp
+++ b/src/IceGlobalContext.cpp
@@ -119,7 +119,7 @@ GlobalContext::GlobalContext(llvm::raw_ostream *OsDump,
     : StrDump(OsDump), StrEmit(OsEmit), VMask(Mask),
       ConstPool(new ConstantPool()), Arch(Arch), Opt(Opt),
       TestPrefix(TestPrefix), Flags(Flags), HasEmittedFirstMethod(false),
-      RNG(""), Timers(new TimerStack("main")) {}
+      RNG("") {}
 
 // Scan a string for S[0-9A-Z]*_ patterns and replace them with
 // S<num>_ where <num> is the next base-36 value.  If a type name
@@ -385,9 +385,20 @@ TimerIdT GlobalContext::getTimerID(const IceString &Name) {
   return TimerStack::getTimerID(Name);
 }
 
-void GlobalContext::pushTimer(TimerIdT ID) { Timers->push(ID); }
+TimerStackIdT GlobalContext::NumTimerStacks = GlobalContext::TSK_Num;
 
-void GlobalContext::popTimer(TimerIdT ID) { Timers->pop(ID); }
+TimerStackIdT GlobalContext::getTimerStackID() { return NumTimerStacks++; }
+
+void GlobalContext::pushTimer(TimerIdT ID, TimerStackIdT StackID) {
+  if (Timers.size() <= StackID)
+    Timers.resize(StackID + 1);
+  Timers[StackID].push(ID);
+}
+
+void GlobalContext::popTimer(TimerIdT ID, TimerStackIdT StackID) {
+  assert(Timers.size() > StackID);
+  Timers[StackID].pop(ID);
+}
 
 void GlobalContext::dumpStats(const IceString &Name, bool Final) {
   if (Flags.DumpStats) {
@@ -400,6 +411,16 @@ void GlobalContext::dumpStats(const IceString &Name, bool Final) {
   }
 }
 
-void GlobalContext::dumpTimers() { Timers->dump(getStrDump()); }
+void GlobalContext::dumpTimers(TimerStackIdT StackID, bool DumpCumulative) {
+  assert(Timers.size() > StackID);
+  Timers[StackID].dump(getStrDump(), DumpCumulative);
+}
+
+TimerMarker::TimerMarker(TimerIdT ID, const Cfg *Func)
+    : ID(ID), Ctx(Func->getContext()),
+      Active(Func->getFocusedTiming() || Ctx->getFlags().SubzeroTimingEnabled) {
+  if (Active)
+    Ctx->pushTimer(ID);
+}
 
 } // end of namespace Ice