[turbofan] inline %StringIteratorPrototype%.next in JSBuiltinReducer.

src/compiler/access-builder.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/access-builder.h"
 
 #include "src/compiler/type-cache.h"
 #include "src/contexts.h"
 #include "src/frames.h"
 #include "src/handles-inl.h"
@@ skipping 530 matching lines @@
 FieldAccess AccessBuilder::ForJSGlobalObjectNativeContext() {
   FieldAccess access = {kTaggedBase,
                         JSGlobalObject::kNativeContextOffset,
                         Handle<Name>(),
                         Type::Internal(),
                         MachineType::TaggedPointer(),
                         kPointerWriteBarrier};
   return access;
 }
 
+// static
+FieldAccess AccessBuilder::ForJSStringIteratorString() {
+  FieldAccess access = {
+      kTaggedBase,    JSStringIterator::kStringOffset, Handle<String>(),
+      Type::String(), MachineType::TaggedPointer(),    kNoWriteBarrier};

[Benedikt Meurer, 2016/09/29 13:04:27]

This should be kPointerWriteBarrier.

+  return access;
+}
+
+// static
+FieldAccess AccessBuilder::ForJSStringIteratorIndex() {
+  FieldAccess access = {
+      kTaggedBase,          JSStringIterator::kNextIndexOffset,
+      Handle<String>(),     Type::Signed32(),

[Benedikt Meurer, 2016/09/29 13:04:26]

The type of this field is Type::UnsignedSmall(), as it can only contain positive
Smis. Actually it can only contain Smis in the range [0, String::kMaxLength], so
this should be TypeCache::Get().kStringLengthType instead.

+      MachineType::Int32(), kNoWriteBarrier};

[Benedikt Meurer, 2016/09/29 13:04:27]

This should be MachineType::TaggedSigned() instead of MachineType::Int32().

+  return access;
+}
 
 // static
 FieldAccess AccessBuilder::ForValue() {
   FieldAccess access = {
       kTaggedBase,         JSValue::kValueOffset,    Handle<Name>(),
       Type::NonInternal(), MachineType::AnyTagged(), kFullWriteBarrier};
   return access;
 }
 
 
@@ skipping 165 matching lines @@
   }
   UNREACHABLE();
   ElementAccess access = {kUntaggedBase, 0, Type::None(), MachineType::None(),
                           kNoWriteBarrier};
   return access;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8