[Intl] Use bit field accessors for style and numeric values

Bug: v8:7869
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: I91bb1948a46249157e143733862c0eeefd15cb0d
Reviewed-on: https://chromium-review.googlesource.com/1137365
Commit-Queue: Frank Tang <ftang@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54529}

src/builtins/builtins-intl.cc

@@ -1011,16 +1011,18 @@ BUILTIN(RelativeTimeFormatConstructor) {
   //                                    "%RelativeTimeFormatPrototype%").
   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
                                      JSObject::New(target, new_target));
+  Handle<JSRelativeTimeFormat> format =
+      Handle<JSRelativeTimeFormat>::cast(result);
+  format->set_flags(0);
 
   Handle<Object> locales = args.atOrUndefined(isolate, 1);
   Handle<Object> options = args.atOrUndefined(isolate, 2);
 
   // 3. Return ? InitializeRelativeTimeFormat(relativeTimeFormat, locales,
   //                                          options).
-  RETURN_RESULT_OR_FAILURE(
-      isolate, JSRelativeTimeFormat::InitializeRelativeTimeFormat(
-                   isolate, Handle<JSRelativeTimeFormat>::cast(result), locales,
-                   options));
+  RETURN_RESULT_OR_FAILURE(isolate,
+                           JSRelativeTimeFormat::InitializeRelativeTimeFormat(
+                               isolate, format, locales, options));
 }
 
 BUILTIN(RelativeTimeFormatPrototypeResolvedOptions) {

src/objects-debug.cc

@@ -1861,9 +1861,8 @@ void JSLocale::JSLocaleVerify(Isolate* isolate) {
 
 void JSRelativeTimeFormat::JSRelativeTimeFormatVerify(Isolate* isolate) {
   VerifyObjectField(isolate, kLocaleOffset);
-  VerifyObjectField(isolate, kStyleOffset);
-  VerifyObjectField(isolate, kNumericOffset);
   VerifyObjectField(isolate, kFormatterOffset);
+  VerifyObjectField(isolate, kFlagsOffset);
 }
 #endif  // V8_INTL_SUPPORT
 

src/objects/js-relative-time-format-inl.h

@@ -19,37 +19,32 @@ namespace v8 {
 namespace internal {
 
 // Base relative time format accessors.
-ACCESSORS(JSRelativeTimeFormat, locale, String, kLocaleOffset);
-ACCESSORS(JSRelativeTimeFormat, formatter, Foreign, kFormatterOffset);
+ACCESSORS(JSRelativeTimeFormat, locale, String, kLocaleOffset)
+ACCESSORS(JSRelativeTimeFormat, formatter, Foreign, kFormatterOffset)
+SMI_ACCESSORS(JSRelativeTimeFormat, flags, kFlagsOffset)
 
 // TODO(ftang): Use bit field accessor for style and numeric later.
 
 inline void JSRelativeTimeFormat::set_style(Style style) {
   DCHECK_GT(Style::COUNT, style);
-  int value = static_cast<int>(style);
-  WRITE_FIELD(this, kStyleOffset, Smi::FromInt(value));
+  int hints = flags();
+  hints = StyleBits::update(hints, style);
+  set_flags(hints);
 }
 
 inline JSRelativeTimeFormat::Style JSRelativeTimeFormat::style() const {
-  Object* value = READ_FIELD(this, kStyleOffset);
-  int style = Smi::ToInt(value);
-  DCHECK_LE(0, style);
-  DCHECK_GT(static_cast<int>(Style::COUNT), style);
-  return static_cast<Style>(style);
+  return StyleBits::decode(flags());
 }
 
 inline void JSRelativeTimeFormat::set_numeric(Numeric numeric) {
   DCHECK_GT(Numeric::COUNT, numeric);
-  int value = static_cast<int>(numeric);
-  WRITE_FIELD(this, kNumericOffset, Smi::FromInt(value));
+  int hints = flags();
+  hints = NumericBits::update(hints, numeric);
+  set_flags(hints);
 }
 
 inline JSRelativeTimeFormat::Numeric JSRelativeTimeFormat::numeric() const {
-  Object* value = READ_FIELD(this, kNumericOffset);
-  int numeric = Smi::ToInt(value);
-  DCHECK_LE(0, numeric);
-  DCHECK_GT(static_cast<int>(Numeric::COUNT), numeric);
-  return static_cast<Numeric>(numeric);
+  return NumericBits::decode(flags());
 }
 
 CAST_ACCESSOR(JSRelativeTimeFormat);

src/objects/js-relative-time-format.cc

@@ -61,7 +61,7 @@ JSRelativeTimeFormat::InitializeRelativeTimeFormat(
     Isolate* isolate, Handle<JSRelativeTimeFormat> relative_time_format_holder,
     Handle<Object> input_locales, Handle<Object> input_options) {
   Factory* factory = isolate->factory();
-
+  relative_time_format_holder->set_flags(0);
   // 4. If options is undefined, then
   Handle<JSReceiver> options;
   if (input_options->IsUndefined(isolate)) {

src/objects/js-relative-time-format.h

@@ -46,10 +46,9 @@ class JSRelativeTimeFormat : public JSObject {
 
   // RelativeTimeFormat accessors.
   DECL_ACCESSORS(locale, String)
-  // TODO(ftang): Style requires only 3 bits and Numeric requires only 2 bits
-  // but here we're using 64 bits for each. We should fold these two fields into
-  // a single Flags field and use BIT_FIELD_ACCESSORS to access it.
-  //
+
+  DECL_ACCESSORS(formatter, Foreign)
+
   // Style: identifying the relative time format style used.
   //
   // ecma402/#sec-properties-of-intl-relativetimeformat-instances
@@ -77,20 +76,31 @@ class JSRelativeTimeFormat : public JSObject {
   inline void set_numeric(Numeric numeric);
   inline Numeric numeric() const;
 
-  DECL_ACCESSORS(formatter, Foreign)
+// Bit positions in |flags|.
+#define FLAGS_BIT_FIELDS(V, _) \
+  V(StyleBits, Style, 2, _)    \
+  V(NumericBits, Numeric, 1, _)
+  DEFINE_BIT_FIELDS(FLAGS_BIT_FIELDS)
+#undef FLAGS_BIT_FIELDS
+
+  STATIC_ASSERT(Style::LONG <= StyleBits::kMax);
+  STATIC_ASSERT(Style::SHORT <= StyleBits::kMax);
+  STATIC_ASSERT(Style::NARROW <= StyleBits::kMax);
+  STATIC_ASSERT(Numeric::AUTO <= NumericBits::kMax);
+  STATIC_ASSERT(Numeric::ALWAYS <= NumericBits::kMax);
+
+  // [flags] Bit field containing various flags about the function.
+  DECL_INT_ACCESSORS(flags)
+
   DECL_PRINTER(JSRelativeTimeFormat)
   DECL_VERIFIER(JSRelativeTimeFormat)
 
   // Layout description.
   static const int kJSRelativeTimeFormatOffset = JSObject::kHeaderSize;
   static const int kLocaleOffset = kJSRelativeTimeFormatOffset + kPointerSize;
-  static const int kStyleOffset = kLocaleOffset + kPointerSize;
-  static const int kNumericOffset = kStyleOffset + kPointerSize;
-  static const int kFormatterOffset = kNumericOffset + kPointerSize;
-  static const int kSize = kFormatterOffset + kPointerSize;
-
-  // Constant to access field
-  static const int kFormatterField = 3;
+  static const int kFormatterOffset = kLocaleOffset + kPointerSize;
+  static const int kFlagsOffset = kFormatterOffset + kPointerSize;
+  static const int kSize = kFlagsOffset + kPointerSize;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSRelativeTimeFormat);