[Tracing] Implement IC statistics in tracing.

src/code-stubs.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-stubs.h"
 
 #include <sstream>
 
 #include "src/ast/ast.h"
 #include "src/bootstrapper.h"
 #include "src/code-factory.h"
 #include "src/code-stub-assembler.h"
 #include "src/factory.h"
 #include "src/gdb-jit.h"
 #include "src/ic/accessor-assembler.h"
 #include "src/ic/handler-compiler.h"
+#include "src/ic/ic-stats.h"
 #include "src/ic/ic.h"
 #include "src/macro-assembler.h"
+#include "src/tracing/tracing-category-observer.h"
 
 namespace v8 {
 namespace internal {
 
 using compiler::CodeAssemblerState;
 
 RUNTIME_FUNCTION(UnexpectedStubMiss) {
   FATAL("Unexpected deopt of a stub");
   return Smi::kZero;
 }
@@ skipping 2254 matching lines @@
   Node* context = assembler.Parameter(4);
   assembler.TailCallRuntime(Runtime::kCreateObjectLiteral, context, closure,
                             literals_index, constant_properties, flags);
 }
 
 template<class StateType>
 void HydrogenCodeStub::TraceTransition(StateType from, StateType to) {
   // Note: Although a no-op transition is semantically OK, it is hinting at a
   // bug somewhere in our state transition machinery.
   DCHECK(from != to);
-  if (!FLAG_trace_ic) return;
-  OFStream os(stdout);
-  os << "[";
-  PrintBaseName(os);
-  os << ": " << from << "=>" << to << "]" << std::endl;
+  if (V8_LIKELY(!FLAG_ic_stats)) return;
+  if (FLAG_ic_stats &

[Camillo Bruni, 2016/12/02 12:12:55]

no need to check the flag again.

[lpy, 2016/12/05 17:49:10]

but we want to check if the flag is enabled by tracing or not, and if the flag
is set and not enabled by tracing, then it's enabled by command line.

+      v8::tracing::TracingCategoryObserver::ENABLED_BY_TRACING) {
+    auto ic_stats = ICStats::instance();
+    ic_stats->Begin();
+    ICInfo& ic_info = ic_stats->Current();
+    ic_info.type = MajorName(MajorKey());
+    ic_info.state = ToString(from);
+    ic_info.state += "=>";
+    ic_info.state += ToString(to);
+    ic_stats->End();
+  } else if (FLAG_ic_stats) {

[Camillo Bruni, 2016/12/02 12:12:55]

same here.

[lpy, 2016/12/05 17:49:10]

see explanation above.

[Camillo Bruni, 2016/12/05 20:13:50]

Argh, sorry I misread the single & above, but nevertheless, you can drop this
second check then as this will be certainly true.

+    OFStream os(stdout);
+    os << "[";
+    PrintBaseName(os);
+    os << ": " << from << "=>" << to << "]" << std::endl;
+  }
 }
 
 void CallICStub::PrintState(std::ostream& os) const {  // NOLINT
   os << state();
 }
 
 
 void JSEntryStub::FinishCode(Handle<Code> code) {
   Handle<FixedArray> handler_table =
       code->GetIsolate()->factory()->NewFixedArray(1, TENURED);
@@ skipping 906 matching lines @@
 }
 
 ArrayConstructorStub::ArrayConstructorStub(Isolate* isolate)
     : PlatformCodeStub(isolate) {}
 
 InternalArrayConstructorStub::InternalArrayConstructorStub(Isolate* isolate)
     : PlatformCodeStub(isolate) {}
 
 }  // namespace internal
 }  // namespace v8