Subzero: Add a few performance measurement tools.

src/IceGlobalContext.h

Index: src/IceGlobalContext.h
diff --git a/src/IceGlobalContext.h b/src/IceGlobalContext.h
index 0ffff1c3d9013979f8f18cc0cacd0b05bd7d919b..5b0baef4d93eabe02c7e694000464cdd29115413 100644
--- a/src/IceGlobalContext.h
+++ b/src/IceGlobalContext.h
@@ -23,6 +23,7 @@
 #include "IceDefs.h"
 #include "IceIntrinsics.h"
 #include "IceRNG.h"
+#include "IceTimerTree.h"
 #include "IceTypes.h"
 
 namespace Ice {
@@ -71,6 +72,7 @@ public:
   // Returns true if any of the specified options in the verbose mask
   // are set.  If the argument is omitted, it checks if any verbose
   // options at all are set.
+  VerboseMask getVerbose() const { return VMask; }
   bool isVerbose(VerboseMask Mask = IceV_All) const { return VMask & Mask; }
   void setVerbose(VerboseMask Mask) { VMask = Mask; }
   void addVerbose(VerboseMask Mask) { VMask |= Mask; }
@@ -151,10 +153,19 @@ public:
     StatsCumulative.updateFills();
   }
 
+  // These are predefined TimerStackIdT values.
+  enum TimerStackKind {
+    TSK_Default = 0,
+    TSK_Funcs,
+    TSK_Num
+  };
+
   static TimerIdT getTimerID(const IceString &Name);
-  void pushTimer(TimerIdT ID);
-  void popTimer(TimerIdT ID);
-  void dumpTimers();
+  static TimerStackIdT getTimerStackID();

[jvoung (off chromium), 2014/10/06 16:30:56]

How is getTimerStackID() planned to be used? (I don't see a user in this patch
set)

At first I thought there was a new timerstackid per function, but it looks like
it's a separate timer ID instead (using the function name).

[Jim Stichnoth, 2014/10/06 21:29:57]

The thought is that some component, e.g. the bitcode parser, could use this
along with instrumenting its own code.  The advantage is that it's easily
accessible through the GlobalContext object.

BTW, I changed this to be non-static, and the GlobalContext ctor uses it to
pre-allocate the two predefined timer stacks.

+  void pushTimer(TimerIdT ID, TimerStackIdT StackID = TSK_Default);
+  void popTimer(TimerIdT ID, TimerStackIdT StackID = TSK_Default);
+  void dumpTimers(TimerStackIdT StackID = TSK_Default,
+                  bool DumpCumulative = true);
 
 private:
   Ostream *StrDump; // Stream for dumping / diagnostics
@@ -172,7 +183,8 @@ private:
   RandomNumberGenerator RNG;
   CodeStats StatsFunction;
   CodeStats StatsCumulative;
-  std::unique_ptr<class TimerStack> Timers;
+  std::vector<TimerStack> Timers;
+  static TimerStackIdT NumTimerStackIds;
   GlobalContext(const GlobalContext &) = delete;
   GlobalContext &operator=(const GlobalContext &) = delete;
 
@@ -194,6 +206,8 @@ public:
     if (Active)
       Ctx->pushTimer(ID);
   }
+  TimerMarker(TimerIdT ID, const Cfg *Func);
+
   ~TimerMarker() {
     if (Active)
       Ctx->popTimer(ID);