Reland "Allow inlining of functions containing %_ArgumentsLength."

src/hydrogen.cc

 // Copyright 2013 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/hydrogen.h"
 
 #include <algorithm>
 
 #include "src/v8.h"
 
@@ skipping 11292 matching lines @@
     return ast_context()->ReturnValue(value);
   } else {
     return ast_context()->ReturnControl(New<HIsConstructCallAndBranch>(),
                                         call->id());
   }
 }
 
 
 // Support for arguments.length and arguments[?].
 void HOptimizedGraphBuilder::GenerateArgumentsLength(CallRuntime* call) {
-  // Our implementation of arguments (based on this stack frame or an
-  // adapter below it) does not work for inlined functions.  This runtime
-  // function is blacklisted by AstNode::IsInlineable.
-  ASSERT(function_state()->outer() == NULL);
   ASSERT(call->arguments()->length() == 0);
-  HInstruction* elements = Add<HArgumentsElements>(false);
-  HArgumentsLength* result = New<HArgumentsLength>(elements);
+  HInstruction* result = NULL;
+  if (function_state()->outer() == NULL) {
+    HInstruction* elements = Add<HArgumentsElements>(false);
+    result = New<HArgumentsLength>(elements);
+  } else {
+    // Number of arguments without receiver.
+    int argument_count = environment()->
+        arguments_environment()->parameter_count() - 1;
+    result = New<HConstant>(argument_count);
+  }
   return ast_context()->ReturnInstruction(result, call->id());
 }
 
 
 void HOptimizedGraphBuilder::GenerateArguments(CallRuntime* call) {
   // Our implementation of arguments (based on this stack frame or an
   // adapter below it) does not work for inlined functions.  This runtime
   // function is blacklisted by AstNode::IsInlineable.
   ASSERT(function_state()->outer() == NULL);
   ASSERT(call->arguments()->length() == 1);
@@ skipping 1022 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal