Recover performance of array buffer view field accesses in ICs

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 0faa4af6ffd2c4edf0b007b89363623a77f58e31..25a789867ebe438aea29b031b76d17de5fec2d35 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -3171,6 +3171,43 @@ HInstruction* HGraphBuilder::BuildGetArrayFunction() {
 }
 
 
+HInstruction* HGraphBuilder::BuildArrayBufferViewFieldAccessor(
+    HValue* object, FieldIndex index) {
+  NoObservableSideEffectsScope scope(this);
+  HObjectAccess access = HObjectAccess::ForObservableJSObjectOffset(
+      index.offset(), Representation::Tagged());
+  HInstruction* buffer = Add<HLoadNamedField>(
+      object, nullptr, HObjectAccess::ForJSArrayBufferViewBuffer());
+  HInstruction* field = Add<HLoadNamedField>(object, nullptr, access);
+
+  IfBuilder if_has_buffer(this);
+  if_has_buffer.IfNot<HIsSmiAndBranch>(buffer);
+  if_has_buffer.Then();
+  {
+    HInstruction* flags = Add<HLoadNamedField>(
+        buffer, nullptr, HObjectAccess::ForJSArrayBufferFlag());
+    HValue* was_neutered_mask =
+        Add<HConstant>(1 << JSArrayBuffer::kWasNeuteredBit);
+    HValue* was_neutered_test =
+        AddUncasted<HBitwise>(Token::BIT_AND, flags, was_neutered_mask);
+
+    IfBuilder if_was_neutered(this);
+    if_was_neutered.If<HCompareNumericAndBranch>(
+        was_neutered_test, graph()->GetConstant0(), Token::NE);
+    if_was_neutered.Then();
+    Push(graph()->GetConstant0());
+    if_was_neutered.Else();
+    Push(field);
+    if_was_neutered.End();
+  }
+  if_has_buffer.Else();
+  Push(field);
+  if_has_buffer.End();
+
+  return HInstruction::cast(Pop());
+}
+
+
 HGraphBuilder::JSArrayBuilder::JSArrayBuilder(HGraphBuilder* builder,
     ElementsKind kind,
     HValue* allocation_site_payload,
@@ -9931,62 +9968,41 @@ void HOptimizedGraphBuilder::GenerateArrayBufferGetByteLength(
 }
 
 
-void HOptimizedGraphBuilder::GenerateArrayBufferViewIndirectAccessor(
-    CallRuntime* expr, HObjectAccess access) {
+void HOptimizedGraphBuilder::GenerateArrayBufferViewGetByteLength(
+    CallRuntime* expr) {
   NoObservableSideEffectsScope scope(this);
   DCHECK(expr->arguments()->length() == 1);
   CHECK_ALIVE(VisitForValue(expr->arguments()->at(0)));
   HValue* view = Pop();
-  HInstruction* buffer = Add<HLoadNamedField>(
-      view, nullptr, HObjectAccess::ForJSArrayBufferViewBuffer());
-  HInstruction* field = Add<HLoadNamedField>(view, nullptr, access);
-
-  IfBuilder if_has_buffer(this);
-  if_has_buffer.IfNot<HIsSmiAndBranch>(buffer);
-  if_has_buffer.Then();
-  {
-    HInstruction* flags = Add<HLoadNamedField>(
-        buffer, nullptr, HObjectAccess::ForJSArrayBufferFlag());
-    HValue* was_neutered_mask =
-        Add<HConstant>(1 << JSArrayBuffer::kWasNeuteredBit);
-    HValue* was_neutered_test =
-        AddUncasted<HBitwise>(Token::BIT_AND, flags, was_neutered_mask);
 
-    IfBuilder if_was_neutered(this);
-    if_was_neutered.If<HCompareNumericAndBranch>(
-        was_neutered_test, graph()->GetConstant0(), Token::NE);
-    if_was_neutered.Then();
-    Push(graph()->GetConstant0());
-    if_was_neutered.Else();
-    Push(field);
-    if_was_neutered.End();
-  }
-  if_has_buffer.Else();
-  Push(field);
-  if_has_buffer.End();
-
-  return ast_context()->ReturnValue(Pop());
-}
-
-
-void HOptimizedGraphBuilder::GenerateArrayBufferViewGetByteLength(
-    CallRuntime* expr) {
-  return GenerateArrayBufferViewIndirectAccessor(
-      expr, HObjectAccess::ForJSArrayBufferViewByteLength());
+  return ast_context()->ReturnValue(BuildArrayBufferViewFieldAccessor(
+      view,
+      FieldIndex::ForInObjectOffset(JSArrayBufferView::kByteLengthOffset)));
 }
 
 
 void HOptimizedGraphBuilder::GenerateArrayBufferViewGetByteOffset(
     CallRuntime* expr) {
-  return GenerateArrayBufferViewIndirectAccessor(
-      expr, HObjectAccess::ForJSArrayBufferViewByteOffset());
+  NoObservableSideEffectsScope scope(this);
+  DCHECK(expr->arguments()->length() == 1);
+  CHECK_ALIVE(VisitForValue(expr->arguments()->at(0)));
+  HValue* view = Pop();
+
+  return ast_context()->ReturnValue(BuildArrayBufferViewFieldAccessor(
+      view,
+      FieldIndex::ForInObjectOffset(JSArrayBufferView::kByteOffsetOffset)));
 }
 
 
 void HOptimizedGraphBuilder::GenerateTypedArrayGetLength(
     CallRuntime* expr) {
-  return GenerateArrayBufferViewIndirectAccessor(
-      expr, HObjectAccess::ForJSTypedArrayLength());
+  NoObservableSideEffectsScope scope(this);
+  DCHECK(expr->arguments()->length() == 1);
+  CHECK_ALIVE(VisitForValue(expr->arguments()->at(0)));
+  HValue* view = Pop();
+
+  return ast_context()->ReturnValue(BuildArrayBufferViewFieldAccessor(
+      view, FieldIndex::ForInObjectOffset(JSTypedArray::kLengthOffset)));
 }