HydrogenCodeStubs consume stack arguments via descriptor.

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/bailout-reason.h"
 #include "src/code-stubs.h"
 #include "src/field-index.h"
 #include "src/hydrogen.h"
@@ skipping 30 matching lines @@
         info_(info),
         descriptor_(info->code_stub()),
         context_(NULL) {
     int parameter_count = GetParameterCount();
     parameters_.Reset(new HParameter*[parameter_count]);
   }
   virtual bool BuildGraph();
 
  protected:
   virtual HValue* BuildCodeStub() = 0;
-  int GetParameterCount() const {
+  int GetParameterCount() const { return descriptor_.GetParameterCount(); }
+  int GetRegisterParameterCount() const {
     return descriptor_.GetRegisterParameterCount();
   }
   HParameter* GetParameter(int parameter) {
     DCHECK(parameter < GetParameterCount());
     return parameters_[parameter];
   }
   Representation GetParameterRepresentation(int parameter) {
     return RepresentationFromType(descriptor_.GetParameterType(parameter));
   }
   bool IsParameterCountRegister(int index) const {
@@ skipping 69 matching lines @@
   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 = GetParameterCount();
+  int register_param_count = GetRegisterParameterCount();
   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();
   HInstruction* stack_parameter_count = NULL;
   for (int i = 0; i < param_count; ++i) {
     Representation r = GetParameterRepresentation(i);
-    HParameter* param = Add<HParameter>(i,
-                                        HParameter::REGISTER_PARAMETER, r);
+    HParameter* param;
+    if (i >= register_param_count) {
+      param = Add<HParameter>(i - register_param_count,
+                              HParameter::STACK_PARAMETER, r);
+    } else {
+      param = Add<HParameter>(i, HParameter::REGISTER_PARAMETER, r);
+    }
     start_environment->Bind(i, param);
     parameters_[i] = param;
-    if (IsParameterCountRegister(i)) {
+    if (i < register_param_count && IsParameterCountRegister(i)) {
       param->set_type(HType::Smi());
       stack_parameter_count = param;
       arguments_length_ = stack_parameter_count;
     }
   }
 
   DCHECK(!runtime_stack_params || arguments_length_ != NULL);
   if (!runtime_stack_params) {
-    stack_parameter_count = graph()->GetConstantMinus1();
+    stack_parameter_count =
+        Add<HConstant>(param_count - register_param_count - 1);
+    // graph()->GetConstantMinus1();
     arguments_length_ = graph()->GetConstant0();
   }
 
   context_ = Add<HContext>();
   start_environment->BindContext(context_);
 
   Add<HSimulate>(BailoutId::StubEntry());
 
   NoObservableSideEffectsScope no_effects(this);
 
@@ skipping 2300 matching lines @@
   return Pop();
 }
 
 
 Handle<Code> KeyedLoadGenericStub::GenerateCode() {
   return DoGenerateCode(this);
 }
 
 }  // namespace internal
 }  // namespace v8