[runtime] Optimize and unify rest parameters.

src/compiler/js-call-reducer.cc

 // Copyright 2015 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/compiler/js-call-reducer.h"
 
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-matchers.h"
 #include "src/objects-inl.h"
 #include "src/type-feedback-vector-inl.h"
@@ skipping 111 matching lines @@
     if (arg_array->opcode() != IrOpcode::kJSCreateArguments) return NoChange();
     for (Edge edge : arg_array->use_edges()) {
       if (edge.from()->opcode() == IrOpcode::kStateValues) continue;
       if (!NodeProperties::IsValueEdge(edge)) continue;
       if (edge.from() == node) continue;
       return NoChange();
     }
     // Get to the actual frame state from which to extract the arguments;
     // we can only optimize this in case the {node} was already inlined into
     // some other function (and same for the {arg_array}).
-    CreateArgumentsParameters const& p =
-        CreateArgumentsParametersOf(arg_array->op());
+    CreateArgumentsType type = CreateArgumentsTypeOf(arg_array->op());
     Node* frame_state = NodeProperties::GetFrameStateInput(arg_array, 0);
     Node* outer_state = frame_state->InputAt(kFrameStateOuterStateInput);
     if (outer_state->opcode() != IrOpcode::kFrameState) return NoChange();
     FrameStateInfo outer_info = OpParameter<FrameStateInfo>(outer_state);
     if (outer_info.type() == FrameStateType::kArgumentsAdaptor) {
       // Need to take the parameters from the arguments adaptor.
       frame_state = outer_state;
     }
     FrameStateInfo state_info = OpParameter<FrameStateInfo>(frame_state);
-    if (p.type() == CreateArgumentsParameters::kMappedArguments) {
+    int start_index = 0;
+    if (type == CreateArgumentsType::kMappedArguments) {
       // Mapped arguments (sloppy mode) cannot be handled if they are aliased.
       Handle<SharedFunctionInfo> shared;
       if (!state_info.shared_info().ToHandle(&shared)) return NoChange();
       if (shared->internal_formal_parameter_count() != 0) return NoChange();
+    } else if (type == CreateArgumentsType::kRestParameter) {
+      Handle<SharedFunctionInfo> shared;
+      if (!state_info.shared_info().ToHandle(&shared)) return NoChange();
+      start_index = shared->internal_formal_parameter_count();
     }
     // Remove the argArray input from the {node}.
     node->RemoveInput(static_cast<int>(--arity));
     // Add the actual parameters to the {node}, skipping the receiver.
     Node* const parameters = frame_state->InputAt(kFrameStateParametersInput);
-    for (int i = p.start_index() + 1; i < state_info.parameter_count(); ++i) {
+    for (int i = start_index + 1; i < state_info.parameter_count(); ++i) {
       node->InsertInput(graph()->zone(), static_cast<int>(arity),
                         parameters->InputAt(i));
       ++arity;
     }
     // Drop the {target} from the {node}.
     node->RemoveInput(0);
     --arity;
   } else {
     return NoChange();
   }
@@ skipping 387 matching lines @@
 }
 
 
 JSOperatorBuilder* JSCallReducer::javascript() const {
   return jsgraph()->javascript();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8