When marking dependent code for deoptimization print the group that is being deoptimized.

Otherwise it is impossible to figure out from the --trace-deoptimization output what is going on.

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/467183002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23191 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap/mark-compact.cc

@@ -2724,7 +2724,8 @@ void MarkCompactCollector::ClearDependentCode(DependentCode* entries) {
     DCHECK(entries->is_code_at(i));
     Code* code = entries->code_at(i);
     if (IsMarked(code) && !code->marked_for_deoptimization()) {
-      code->set_marked_for_deoptimization(true);
+      DependentCode::SetMarkedForDeoptimization(
+          code, static_cast<DependentCode::DependencyGroup>(g));
       code->InvalidateEmbeddedObjects();
       have_code_to_deoptimize_ = true;
     }

src/objects.cc

@@ -11786,7 +11786,7 @@ bool DependentCode::MarkCodeForDeoptimization(
     if (is_code_at(i)) {
       Code* code = code_at(i);
       if (!code->marked_for_deoptimization()) {
-        code->set_marked_for_deoptimization(true);
+        SetMarkedForDeoptimization(code, group);
         marked = true;
       }
     } else {
@@ -11837,6 +11837,51 @@ void DependentCode::AddToDependentICList(Handle<Code> stub) {
 }
 
 
+void DependentCode::SetMarkedForDeoptimization(Code* code,
+                                               DependencyGroup group) {
+  code->set_marked_for_deoptimization(true);
+  if (FLAG_trace_deopt &&
+      (code->deoptimization_data() != code->GetHeap()->empty_fixed_array())) {
+    DeoptimizationInputData* deopt_data =
+        DeoptimizationInputData::cast(code->deoptimization_data());
+    CodeTracer::Scope scope(code->GetHeap()->isolate()->GetCodeTracer());
+    PrintF(scope.file(), "[marking dependent code 0x%08" V8PRIxPTR
+                         " (opt #%d) for deoptimization, reason: %s]\n",
+           reinterpret_cast<intptr_t>(code),
+           deopt_data->OptimizationId()->value(), DependencyGroupName(group));
+  }
+}
+
+
+const char* DependentCode::DependencyGroupName(DependencyGroup group) {
+  switch (group) {
+    case kWeakICGroup:
+      return "weak-ic";
+    case kWeakCodeGroup:
+      return "weak-code";
+    case kTransitionGroup:
+      return "transition";
+    case kPrototypeCheckGroup:
+      return "prototype-check";
+    case kElementsCantBeAddedGroup:
+      return "elements-cant-be-added";
+    case kPropertyCellChangedGroup:
+      return "property-cell-changed";
+    case kFieldTypeGroup:
+      return "field-type";
+    case kInitialMapChangedGroup:
+      return "initial-map-changed";
+    case kAllocationSiteTenuringChangedGroup:
+      return "allocation-site-tenuring-changed";
+    case kAllocationSiteTransitionChangedGroup:
+      return "allocation-site-transition-changed";
+    default:
+      UNREACHABLE();
+      return "?";
+  }
+}
+
+
 Handle<Map> Map::TransitionToPrototype(Handle<Map> map,
                                        Handle<Object> prototype) {
   Handle<Map> new_map = GetPrototypeTransition(map, prototype);

src/objects.h

@@ -6006,6 +6006,9 @@ class DependentCode: public FixedArray {
   static DependentCode* ForObject(Handle<HeapObject> object,
                                   DependencyGroup group);
 
+  static const char* DependencyGroupName(DependencyGroup group);
+  static void SetMarkedForDeoptimization(Code* code, DependencyGroup group);
+
  private:
   // Make a room at the end of the given group by moving out the first
   // code objects of the subsequent groups.