[runtime] Remove "don't OSR functions which use arguments" logic.

OSR for functions which use arguments no longer needs to be disabled, since
TurboFan handles the case.

Bug: 
Change-Id: I121f1190a142c18f113bd5f875e258812645c43f
Reviewed-on: https://chromium-review.googlesource.com/721661
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48631}

src/ast/scopes.cc

@@ -1554,12 +1554,6 @@ void DeclarationScope::AnalyzePartially(AstNodeFactory* ast_node_factory) {
       unresolved = copy;
     }
 
-    // Clear arguments_ if unused. This is used as a signal for optimization.
-    if (arguments_ != nullptr &&
-        !(MustAllocate(arguments_) && !has_arguments_parameter_)) {
-      arguments_ = nullptr;
-    }
-
     // Migrate function_ to the right Zone.
     if (function_ != nullptr) {
       function_ = ast_node_factory->CopyVariable(function_);

src/objects.cc

@@ -13756,7 +13756,6 @@ void SharedFunctionInfo::InitFromFunctionLiteral(
   shared_info->set_inferred_name(*lit->inferred_name());
   shared_info->set_allows_lazy_compilation(lit->AllowsLazyCompilation());
   shared_info->set_language_mode(lit->language_mode());
-  shared_info->set_uses_arguments(lit->scope()->arguments() != nullptr);
   //  shared_info->set_kind(lit->kind());
   // FunctionKind must have already been set.
   DCHECK(lit->kind() == shared_info->kind());

src/objects/shared-function-info-inl.h

@@ -84,8 +84,6 @@ AbstractCode* SharedFunctionInfo::abstract_code() {
 
 BIT_FIELD_ACCESSORS(SharedFunctionInfo, compiler_hints, allows_lazy_compilation,
                     SharedFunctionInfo::AllowLazyCompilationBit)
-BIT_FIELD_ACCESSORS(SharedFunctionInfo, compiler_hints, uses_arguments,
-                    SharedFunctionInfo::UsesArgumentsBit)
 BIT_FIELD_ACCESSORS(SharedFunctionInfo, compiler_hints,
                     has_duplicate_parameters,
                     SharedFunctionInfo::HasDuplicateParametersBit)

src/objects/shared-function-info.h

@@ -289,9 +289,6 @@ class SharedFunctionInfo : public HeapObject {
   inline LanguageMode language_mode();
   inline void set_language_mode(LanguageMode language_mode);
 
-  // False if the function definitely does not allocate an arguments object.
-  DECL_BOOLEAN_ACCESSORS(uses_arguments)
-
   // True if the function has any duplicated parameter names.
   DECL_BOOLEAN_ACCESSORS(has_duplicate_parameters)
 
@@ -467,7 +464,6 @@ class SharedFunctionInfo : public HeapObject {
   V(FunctionKindBits, FunctionKind, 10, _) \
   V(HasDuplicateParametersBit, bool, 1, _) \
   V(AllowLazyCompilationBit, bool, 1, _)   \
-  V(UsesArgumentsBit, bool, 1, _)          \
   V(NeedsHomeObjectBit, bool, 1, _)        \
   V(IsDeclarationBit, bool, 1, _)          \
   V(IsAsmWasmBrokenBit, bool, 1, _)        \

src/runtime-profiler.cc

@@ -123,11 +123,6 @@ void RuntimeProfiler::AttemptOnStackReplacement(JavaScriptFrame* frame,
   // If the code is not optimizable, don't try OSR.
   if (shared->optimization_disabled()) return;
 
-  // We are not prepared to do OSR for a function that already has an
-  // allocated arguments object.  The optimized code would bypass it for
-  // arguments accesses, which is unsound.  Don't try OSR.
-  if (shared->uses_arguments()) return;
-
   // We're using on-stack replacement: Store new loop nesting level in
   // BytecodeArray header so that certain back edges in any interpreter frame
   // for this bytecode will trigger on-stack replacement for that frame.

src/runtime/runtime-compiler.cc

@@ -211,9 +211,6 @@ RUNTIME_FUNCTION(Runtime_CompileForOnStackReplacement) {
   DCHECK_EQ(1, args.length());
   CONVERT_ARG_HANDLE_CHECKED(JSFunction, function, 0);
 
-  // We're not prepared to handle a function with arguments object.
-  DCHECK(!function->shared()->uses_arguments());
-
   // Only reachable when OST is enabled.
   CHECK(FLAG_use_osr);
 

test/mjsunit/compiler/osr-arguments.js

@@ -0,0 +1,17 @@
+// Copyright 2017 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.
+
+// Flags: --allow-natives-syntax
+
+function f1() {
+  var sum = 0;
+  for (var i = 0; i < 1000; i++) {
+    sum += arguments[0] + arguments[1] + arguments[2] + arguments[3];
+    if (i == 18) %OptimizeOsr();
+  }
+  return sum;
+}
+
+let result = f1(1, 1, 2, 3);
+assertEquals(7000, result);