[turbofan] Make arguments object materialization inlinable.

src/compiler/js-inlining.cc

 // Copyright 2014 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-inlining.h"
 
 #include "src/ast.h"
 #include "src/ast-numbering.h"
 #include "src/compiler.h"
 #include "src/compiler/all-nodes.h"
@@ skipping 120 matching lines @@
 
   // {inliner_inputs} counts JSFunction, Receiver, arguments, but not
   // context, effect, control.
   int inliner_inputs = call->op()->ValueInputCount();
   // Iterate over all uses of the start node.
   for (Edge edge : start->use_edges()) {
     Node* use = edge.from();
     switch (use->opcode()) {
       case IrOpcode::kParameter: {
         int index = 1 + ParameterIndexOf(use->op());
+        DCHECK_LE(index, inlinee_context_index);
         if (index < inliner_inputs && index < inlinee_context_index) {
           // There is an input from the call, and the index is a value
           // projection but not the context, so rewire the input.
           Replace(use, call->InputAt(index));
         } else if (index == inlinee_context_index) {
+          // The projection is requesting the inlinee function context.
           Replace(use, context);
-        } else if (index < inlinee_context_index) {
+        } else {
           // Call has fewer arguments than required, fill with undefined.
           Replace(use, jsgraph_->UndefinedConstant());
-        } else {
-          // We got too many arguments, discard for now.
-          // TODO(sigurds): Fix to treat arguments array correctly.
         }
         break;
       }
       default:
         if (NodeProperties::IsEffectEdge(edge)) {
           edge.UpdateTo(effect);
         } else if (NodeProperties::IsControlEdge(edge)) {
           edge.UpdateTo(control);
         } else if (NodeProperties::IsFrameStateEdge(edge)) {
           edge.UpdateTo(frame_state);
@@ skipping 149 matching lines @@
     return NoChange();
   }
 
   if (!Compiler::EnsureDeoptimizationSupport(&info)) {
     TRACE("Not inlining %s into %s because deoptimization support failed\n",
           function->shared()->DebugName()->ToCString().get(),
           info_->shared_info()->DebugName()->ToCString().get());
     return NoChange();
   }
 
-  if (info.scope()->arguments() != NULL && is_sloppy(info.language_mode())) {
-    // For now do not inline functions that use their arguments array.
-    TRACE("Not inlining %s into %s because inlinee uses arguments array\n",
-          function->shared()->DebugName()->ToCString().get(),
-          info_->shared_info()->DebugName()->ToCString().get());
-    return NoChange();
-  }
-
   TRACE("Inlining %s into %s\n",
         function->shared()->DebugName()->ToCString().get(),
         info_->shared_info()->DebugName()->ToCString().get());
 
   Graph graph(info.zone());
   JSGraph jsgraph(info.isolate(), &graph, jsgraph_->common(),
                   jsgraph_->javascript(), jsgraph_->machine());
   AstGraphBuilder graph_builder(local_zone_, &info, &jsgraph);
   graph_builder.CreateGraph(false);
 
@@ skipping 25 matching lines @@
 
   // Remember that we inlined this function.
   info_->AddInlinedFunction(info.shared_info());
 
   return InlineCall(node, context, frame_state, start, end);
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8