[builtins] Properly optimize TypedArray/DataView accessors.

src/compiler/js-native-context-specialization.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-native-context-specialization.h"
 
 #include "src/accessors.h"
 #include "src/code-factory.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
@@ skipping 227 matching lines @@
       if (access_mode == AccessMode::kStore) {
         Node* check = graph()->NewNode(
             simplified()->ReferenceEqual(Type::Tagged()), value, this_value);
         this_control = this_effect =
             graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state,
                              this_effect, this_control);
       }
     } else {
       DCHECK(access_info.IsDataField());
       FieldIndex const field_index = access_info.field_index();
-      FieldCheck const field_check = access_info.field_check();
       Type* const field_type = access_info.field_type();
-      switch (field_check) {
-        case FieldCheck::kNone:
-          break;
-        case FieldCheck::kJSArrayBufferViewBufferNotNeutered: {
-          Node* this_buffer = this_effect =
-              graph()->NewNode(simplified()->LoadField(
-                                   AccessBuilder::ForJSArrayBufferViewBuffer()),
-                               this_receiver, this_effect, this_control);
-          Node* this_buffer_bit_field = this_effect =
-              graph()->NewNode(simplified()->LoadField(
-                                   AccessBuilder::ForJSArrayBufferBitField()),
-                               this_buffer, this_effect, this_control);
-          Node* check = graph()->NewNode(
-              machine()->Word32Equal(),
-              graph()->NewNode(machine()->Word32And(), this_buffer_bit_field,
-                               jsgraph()->Int32Constant(
-                                   1 << JSArrayBuffer::WasNeutered::kShift)),
-              jsgraph()->Int32Constant(0));
-          this_control = this_effect =
-              graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state,
-                               this_effect, this_control);
-          break;
-        }
-      }
       if (access_mode == AccessMode::kLoad &&
           access_info.holder().ToHandle(&holder)) {
         this_receiver = jsgraph()->Constant(holder);
       }
       Node* this_storage = this_receiver;
       if (!field_index.is_inobject()) {
         this_storage = this_effect = graph()->NewNode(
             simplified()->LoadField(AccessBuilder::ForJSObjectProperties()),
             this_storage, this_effect, this_control);
       }
@@ skipping 870 matching lines @@
 }
 
 
 SimplifiedOperatorBuilder* JSNativeContextSpecialization::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8