Further improve type optimization reusing the type argument vector of the

runtime/vm/intermediate_language_x64.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_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "lib/error.h"
@@ skipping 1827 matching lines @@
 }
 
 
 void InstantiateTypeArgumentsInstr::EmitNativeCode(
     FlowGraphCompiler* compiler) {
   Register instantiator_reg = locs()->in(0).reg();
   Register result_reg = locs()->out().reg();
 
   // 'instantiator_reg' is the instantiator AbstractTypeArguments object
   // (or null).
-  if (!type_arguments().IsUninstantiatedIdentity()) {
+  if (!type_arguments().IsUninstantiatedIdentity() &&
+      !type_arguments().CanShareInstantiatorTypeArguments(
+          instantiator_class())) {
     // If the instantiator is null and if the type argument vector
     // instantiated from null becomes a vector of dynamic, then use null as
     // the type arguments.
     Label type_arguments_instantiated;
     const intptr_t len = type_arguments().Length();
     if (type_arguments().IsRawInstantiatedRaw(len)) {
       const Immediate& raw_null =
           Immediate(reinterpret_cast<intptr_t>(Object::null()));
       __ cmpq(instantiator_reg, raw_null);
       __ j(EQUAL, &type_arguments_instantiated, Assembler::kNearJump);
@@ skipping 29 matching lines @@
 
 
 void ExtractConstructorTypeArgumentsInstr::EmitNativeCode(
     FlowGraphCompiler* compiler) {
   Register instantiator_reg = locs()->in(0).reg();
   Register result_reg = locs()->out().reg();
   ASSERT(instantiator_reg == result_reg);
 
   // instantiator_reg is the instantiator type argument vector, i.e. an
   // AbstractTypeArguments object (or null).
-  if (!type_arguments().IsUninstantiatedIdentity()) {
+  if (!type_arguments().IsUninstantiatedIdentity() &&
+      !type_arguments().CanShareInstantiatorTypeArguments(
+          instantiator_class())) {
     // If the instantiator is null and if the type argument vector
     // instantiated from null becomes a vector of dynamic, then use null as
     // the type arguments.
     Label type_arguments_instantiated;
     const intptr_t len = type_arguments().Length();
     if (type_arguments().IsRawInstantiatedRaw(len)) {
       const Immediate& raw_null =
           Immediate(reinterpret_cast<intptr_t>(Object::null()));
       __ cmpq(instantiator_reg, raw_null);
       __ j(EQUAL, &type_arguments_instantiated, Assembler::kNearJump);
@@ skipping 22 matching lines @@
 }
 
 
 void ExtractConstructorInstantiatorInstr::EmitNativeCode(
     FlowGraphCompiler* compiler) {
   Register instantiator_reg = locs()->in(0).reg();
   ASSERT(locs()->out().reg() == instantiator_reg);
 
   // instantiator_reg is the instantiator AbstractTypeArguments object
   // (or null).
-  if (type_arguments().IsUninstantiatedIdentity()) {
+  if (type_arguments().IsUninstantiatedIdentity() ||
+      type_arguments().CanShareInstantiatorTypeArguments(
+          instantiator_class())) {
     // The instantiator was used in VisitExtractConstructorTypeArguments as the
     // instantiated type arguments, no proper instantiator needed.
     __ movq(instantiator_reg,
             Immediate(Smi::RawValue(StubCode::kNoInstantiator)));
   } else {
     // If the instantiator is null and if the type argument vector
     // instantiated from null becomes a vector of dynamic, then use null as
     // the type arguments and do not pass the instantiator.
     const intptr_t len = type_arguments().Length();
     if (type_arguments().IsRawInstantiatedRaw(len)) {
@@ skipping 1857 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64