Propagate this-specialization to regular (megamorphic) calls

runtime/vm/flow_graph_compiler.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
@@ skipping 1731 matching lines @@
   code_source_map_builder_->BeginCodeSourceRange(assembler()->CodeSize());
 }
 
 
 void FlowGraphCompiler::EndCodeSourceRange(TokenPosition token_pos) {
   code_source_map_builder_->EndCodeSourceRange(assembler()->CodeSize(),
                                                token_pos);
 }
 
 
+const ICData& FlowGraphCompiler::TrySpecializeICData(const ICData& ic_data,

[Vyacheslav Egorov (Google), 2017/02/23 15:32:37]

If we are placing this function on the FlowGraphCompiler we should call it
better, maybe 

TrySpecializeICDataByReceiverCid(...)

+                                                     intptr_t cid) {
+  Zone* zone = Thread::Current()->zone();
+  if (ic_data.NumArgsTested() != 1) return ic_data;
+
+  if ((ic_data.NumberOfUsedChecks() == 1) && ic_data.HasReceiverClassId(cid)) {
+    return ic_data;  // Nothing to do
+  }
+
+  intptr_t count = 1;
+  const Function& function =
+      Function::Handle(zone, ic_data.GetTargetForReceiverClassId(cid, &count));
+  // TODO(fschneider): Try looking up the function on the class if it is
+  // not found in the ICData.
+  if (!function.IsNull()) {
+    const ICData& new_ic_data = ICData::ZoneHandle(
+        zone, ICData::New(Function::Handle(zone, ic_data.Owner()),
+                          String::Handle(zone, ic_data.target_name()),
+                          Object::empty_array(),  // Dummy argument descriptor.
+                          ic_data.deopt_id(), ic_data.NumArgsTested(), false));
+    new_ic_data.SetDeoptReasons(ic_data.DeoptReasons());
+    new_ic_data.AddReceiverCheck(cid, function, count);
+    return new_ic_data;
+  }
+
+  return ic_data;
+}
+
+
 #if !defined(TARGET_ARCH_DBC)
 // DBC emits calls very differently from other architectures due to its
 // interpreted nature.
 void FlowGraphCompiler::EmitPolymorphicInstanceCall(const ICData& ic_data,
                                                     intptr_t argument_count,
                                                     const Array& argument_names,
                                                     intptr_t deopt_id,
                                                     TokenPosition token_pos,
                                                     LocationSummary* locs,
                                                     bool complete) {
@@ skipping 91 matching lines @@
 
 
 void FlowGraphCompiler::FrameStateClear() {
   ASSERT(!is_optimizing());
   frame_state_.TruncateTo(0);
 }
 #endif  // defined(DEBUG) && !defined(TARGET_ARCH_DBC)
 
 
 }  // namespace dart