The IC exposes a register definition.

src/code-stubs-hydrogen.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/v8.h"
 
 #include "src/code-stubs.h"
 #include "src/field-index.h"
 #include "src/hydrogen.h"
 #include "src/lithium.h"
@@ skipping 21 matching lines @@
 
 
 class CodeStubGraphBuilderBase : public HGraphBuilder {
  public:
   CodeStubGraphBuilderBase(Isolate* isolate, HydrogenCodeStub* stub)
       : HGraphBuilder(&info_),
         arguments_length_(NULL),
         info_(stub, isolate),
         context_(NULL) {
     descriptor_ = stub->GetInterfaceDescriptor();
-    parameters_.Reset(new HParameter*[descriptor_->register_param_count_]);
+    parameters_.Reset(new HParameter*[descriptor_->register_param_count()]);
   }
   virtual bool BuildGraph();
 
  protected:
   virtual HValue* BuildCodeStub() = 0;
   HParameter* GetParameter(int parameter) {
-    ASSERT(parameter < descriptor_->register_param_count_);
+    ASSERT(parameter < descriptor_->register_param_count());
     return parameters_[parameter];
   }
   HValue* GetArgumentsLength() {
     // This is initialized in BuildGraph()
     ASSERT(arguments_length_ != NULL);
     return arguments_length_;
   }
   CompilationInfo* info() { return &info_; }
   HydrogenCodeStub* stub() { return info_.code_stub(); }
   HContext* context() { return context_; }
@@ skipping 49 matching lines @@
   // Update the static counter each time a new code stub is generated.
   isolate()->counters()->code_stubs()->Increment();
 
   if (FLAG_trace_hydrogen_stubs) {
     const char* name = CodeStub::MajorName(stub()->MajorKey(), false);
     PrintF("-----------------------------------------------------------\n");
     PrintF("Compiling stub %s using hydrogen\n", name);
     isolate()->GetHTracer()->TraceCompilation(&info_);
   }
 
-  int param_count = descriptor_->register_param_count_;
+  int param_count = descriptor_->register_param_count();
   HEnvironment* start_environment = graph()->start_environment();
   HBasicBlock* next_block = CreateBasicBlock(start_environment);
   Goto(next_block);
   next_block->SetJoinId(BailoutId::StubEntry());
   set_current_block(next_block);
 
-  bool runtime_stack_params = descriptor_->stack_parameter_count_.is_valid();
+  bool runtime_stack_params = descriptor_->stack_parameter_count().is_valid();
   HInstruction* stack_parameter_count = NULL;
   for (int i = 0; i < param_count; ++i) {
-    Representation r = descriptor_->register_param_representations_ == NULL
-        ? Representation::Tagged()
-        : descriptor_->register_param_representations_[i];
+    Representation r = descriptor_->GetRegisterParameterRepresentation(i);
     HParameter* param = Add<HParameter>(i, HParameter::REGISTER_PARAMETER, r);
     start_environment->Bind(i, param);
     parameters_[i] = param;
     if (descriptor_->IsParameterCountRegister(i)) {
       param->set_type(HType::Smi());
       stack_parameter_count = param;
       arguments_length_ = stack_parameter_count;
     }
   }
 
   ASSERT(!runtime_stack_params || arguments_length_ != NULL);
   if (!runtime_stack_params) {
     stack_parameter_count = graph()->GetConstantMinus1();
     arguments_length_ = graph()->GetConstant0();
   }
 
   context_ = Add<HContext>();
   start_environment->BindContext(context_);
 
   Add<HSimulate>(BailoutId::StubEntry());
 
   NoObservableSideEffectsScope no_effects(this);
 
   HValue* return_value = BuildCodeStub();
 
   // We might have extra expressions to pop from the stack in addition to the
   // arguments above.
   HInstruction* stack_pop_count = stack_parameter_count;
-  if (descriptor_->function_mode_ == JS_FUNCTION_STUB_MODE) {
+  if (descriptor_->function_mode() == JS_FUNCTION_STUB_MODE) {
     if (!stack_parameter_count->IsConstant() &&
-        descriptor_->hint_stack_parameter_count_ < 0) {
+        descriptor_->hint_stack_parameter_count() < 0) {
       HInstruction* constant_one = graph()->GetConstant1();
       stack_pop_count = AddUncasted<HAdd>(stack_parameter_count, constant_one);
       stack_pop_count->ClearFlag(HValue::kCanOverflow);
       // TODO(mvstanton): verify that stack_parameter_count+1 really fits in a
       // smi.
     } else {
-      int count = descriptor_->hint_stack_parameter_count_;
+      int count = descriptor_->hint_stack_parameter_count();
       stack_pop_count = Add<HConstant>(count);
     }
   }
 
   if (current_block() != NULL) {
     HReturn* hreturn_instruction = New<HReturn>(return_value,
                                                 stack_pop_count);
     FinishCurrentBlock(hreturn_instruction);
   }
   return true;
@@ skipping 66 matching lines @@
 }
 
 
 template <class Stub>
 static Handle<Code> DoGenerateCode(Stub* stub) {
   Isolate* isolate = stub->isolate();
   CodeStub::Major  major_key =
       static_cast<HydrogenCodeStub*>(stub)->MajorKey();
   CodeStubInterfaceDescriptor* descriptor =
       isolate->code_stub_interface_descriptor(major_key);
-  if (descriptor->register_param_count_ < 0) {
+  if (!descriptor->initialized()) {
     stub->InitializeInterfaceDescriptor(descriptor);
   }
 
   // If we are uninitialized we can use a light-weight stub to enter
   // the runtime that is significantly faster than using the standard
   // stub-failure deopt mechanism.
   if (stub->IsUninitialized() && descriptor->has_miss_handler()) {
-    ASSERT(!descriptor->stack_parameter_count_.is_valid());
+    ASSERT(!descriptor->stack_parameter_count().is_valid());
     return stub->GenerateLightweightMissCode();
   }
   ElapsedTimer timer;
   if (FLAG_profile_hydrogen_code_stub_compilation) {
     timer.Start();
   }
   CodeStubGraphBuilder<Stub> builder(isolate, stub);
   LChunk* chunk = OptimizeGraph(builder.CreateGraph());
   Handle<Code> code = chunk->Codegen();
   if (FLAG_profile_hydrogen_code_stub_compilation) {
@@ skipping 257 matching lines @@
 
 
 Handle<Code> CreateAllocationSiteStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 
 template <>
 HValue* CodeStubGraphBuilder<KeyedLoadFastElementStub>::BuildCodeStub() {
   HInstruction* load = BuildUncheckedMonomorphicElementAccess(
-      GetParameter(0), GetParameter(1), NULL,
-      casted_stub()->is_js_array(), casted_stub()->elements_kind(),
-      LOAD, NEVER_RETURN_HOLE, STANDARD_STORE);
+      GetParameter(KeyedLoadIC::kReceiverIndex),
+      GetParameter(KeyedLoadIC::kNameIndex),
+      NULL,
+      casted_stub()->is_js_array(),
+      casted_stub()->elements_kind(),
+      LOAD,
+      NEVER_RETURN_HOLE,
+      STANDARD_STORE);
   return load;
 }
 
 
 Handle<Code> KeyedLoadFastElementStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 
 HLoadNamedField* CodeStubGraphBuilderBase::BuildLoadNamedField(
@@ skipping 809 matching lines @@
 }
 
 
 Handle<Code> FastNewContextStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 
 template<>
 HValue* CodeStubGraphBuilder<KeyedLoadDictionaryElementStub>::BuildCodeStub() {
-  HValue* receiver = GetParameter(0);
-  HValue* key = GetParameter(1);
+  HValue* receiver = GetParameter(KeyedLoadIC::kReceiverIndex);
+  HValue* key = GetParameter(KeyedLoadIC::kNameIndex);
 
   Add<HCheckSmi>(key);
 
   HValue* elements = AddLoadElements(receiver);
 
   HValue* hash = BuildElementIndexHash(key);
 
   return BuildUncheckedDictionaryElementLoad(receiver, elements, key, hash);
 }
 
@@ skipping 111 matching lines @@
   BuildElementsKindLimitCheck(if_builder, bit_field2, kind);
 
   Push(BuildUncheckedMonomorphicElementAccess(receiver, key, NULL,
                                               false, kind,
                                               LOAD, NEVER_RETURN_HOLE,
                                               STANDARD_STORE));
 }
 
 
 HValue* CodeStubGraphBuilder<KeyedLoadGenericElementStub>::BuildCodeStub() {
-  HValue* receiver = GetParameter(0);
-  HValue* key = GetParameter(1);
+  HValue* receiver = GetParameter(KeyedLoadIC::kReceiverIndex);
+  HValue* key = GetParameter(KeyedLoadIC::kNameIndex);
 
   // Split into a smi/integer case and unique string case.
   HIfContinuation index_name_split_continuation(graph()->CreateBasicBlock(),
                                                 graph()->CreateBasicBlock());
 
   BuildKeyedIndexCheck(key, &index_name_split_continuation);
 
   IfBuilder index_name_split(this, &index_name_split_continuation);
   index_name_split.Then();
   {
@@ skipping 182 matching lines @@
   return Pop();
 }
 
 
 Handle<Code> KeyedLoadGenericElementStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 
 } }  // namespace v8::internal