Subzero: Rewrite the pass timing infrastructure.

src/IceOperand.cpp

Index: src/IceOperand.cpp
diff --git a/src/IceOperand.cpp b/src/IceOperand.cpp
index d1854f4f0f0a6d4e48306b87acef22f227f2b84b..361472595e7e22734b318a9cec62c84b2ac02f77 100644
--- a/src/IceOperand.cpp
+++ b/src/IceOperand.cpp
@@ -122,9 +122,26 @@ bool LiveRange::overlaps(const LiveRange &Other) const {
 }
 
 bool LiveRange::overlaps(InstNumberT OtherBegin) const {
+  bool Result = false;
+  for (RangeType::const_iterator I = Range.begin(), E = Range.end(); I != E;
+       ++I) {
+    if (OtherBegin < I->first) {
+      Result = false;
+      break;
+    }
+    if (OtherBegin < I->second) {
+      Result = true;
+      break;
+    }
+  }
+#if 0
+  // An equivalent but less inefficient implementation:

[Jim Stichnoth, 2014/09/30 22:46:00]

Actual comparisons indicated this was a lie.

The optimized implementation was completely broken.

For now, I'd like to keep this validation code around and paranoically enable it
at the first sign of suspicion.

   LiveRange Temp;
   Temp.addSegment(OtherBegin, OtherBegin + 1);
-  return overlaps(Temp);
+  bool Validation = overlaps(Temp);
+  assert(Result == Validation);
+#endif
+  return Result;
 }
 
 // Returns true if the live range contains the given instruction
@@ -259,6 +276,8 @@ const Inst *VariableTracking::getSingleDefinition() const {
 }
 
 void VariablesMetadata::init() {
+  static TimerIdT IDvmetadata = GlobalContext::getTimerID("vmetadata");
+  TimerMarker T(IDvmetadata, Func->getContext());
   Metadata.clear();
   Metadata.resize(Func->getNumVariables());