[wrapper-tracing] Force inlining of marking deque helper

third_party/WebKit/Source/platform/heap/WrapperVisitor.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef WrapperVisitor_h
 #define WrapperVisitor_h
 
 #include "platform/PlatformExport.h"
 #include "wtf/Allocator.h"
 
@@ skipping 73 matching lines @@
 #define DEFINE_INLINE_TRACE_WRAPPERS() DECLARE_TRACE_WRAPPERS()
 #define DEFINE_INLINE_VIRTUAL_TRACE_WRAPPERS() DECLARE_VIRTUAL_TRACE_WRAPPERS()
 
 // ###########################################################################
 // TODO(hlopko): Get rid of virtual calls using CRTP
 class PLATFORM_EXPORT WrapperVisitor {
   USING_FAST_MALLOC(WrapperVisitor);
 
  public:
   template <typename T>
-  static NEVER_INLINE void missedWriteBarrier() {
+  static NOINLINE void missedWriteBarrier() {

[Michael Lippautz, 2017/01/18 13:47:40]

https://cs.chromium.org/chromium/src/third_party/WebKit/Source/wtf/Compiler.h...

     NOTREACHED();
   }
 
   template <typename T>
   void traceWrappers(const T* traceable) const {
     static_assert(sizeof(T), "T must be fully defined");
     static_assert(CanTraceWrappers<T>::value,
                   "T should be able to trace wrappers. See "
                   "dispatchTraceWrappers in WrapperVisitor.h");
 
@@ skipping 55 matching lines @@
   virtual bool markWrapperHeader(HeapObjectHeader*) const = 0;
 
   virtual void markWrappersInAllWorlds(const ScriptWrappable*) const = 0;
 
   void markWrappersInAllWorlds(const void*) const {
     // Empty handler used for WRAPPER_VISITOR_SPECIAL_CLASSES. These types
     // don't require marking wrappers in all worlds, so just nop on those.
   }
 
   template <typename T>
-  void markAndPushToMarkingDeque(const T* traceable) const {
+  ALWAYS_INLINE void markAndPushToMarkingDeque(const T* traceable) const {

[Michael Lippautz, 2017/01/18 13:47:40]

The only difference in the CL responsible for the perf regression in the bug is
introduction of this small helper function.

I cannot reproduce locally, so let's try to fix this by forcing inlining (which
should make sense for this one anyways).

     if (pushToMarkingDeque(TraceTrait<T>::traceMarkedWrapper,
                            TraceTrait<T>::heapObjectHeader,
                            WrapperVisitor::missedWriteBarrier<T>, traceable)) {
       TraceTrait<T>::markWrapperNoTracing(this, traceable);
     }
   }
 
  protected:
   // Returns true if pushing to the marking deque was successful.
   virtual bool pushToMarkingDeque(
@@ skipping 10 matching lines @@
     static const bool value = true;                      \
   };
 
 WRAPPER_VISITOR_SPECIAL_CLASSES(SPECIALIZE_WRAPPER_TRACING_MARK_TRAIT)
 
 #undef SPECIALIZE_WRAPPER_TRACING_MARK_TRAIT
 
 }  // namespace blink
 
 #endif  // WrapperVisitor_h