[builtins] Also migrate String.prototype.toLowerCase/toUpperCase to C++.

These builtins always call into C++ anyways and so there's no point in
having the JavaScript wrapper around them, but instead they can be
implemented as C++ builtins directly.

R=franzih@chromium.org
BUG=v8:5049

Review-Url: https://codereview.chromium.org/2018983002
Cr-Commit-Position: refs/heads/master@{#36569}

src/bootstrapper.cc

@@ -1340,6 +1340,17 @@ void Genesis::InitializeGlobal(Handle<JSGlobalObject> global_object,
                           1, true);
     SimpleInstallFunction(prototype, "charCodeAt",
                           Builtins::kStringPrototypeCharCodeAt, 1, true);
+    // TODO(bmeurer): One day we will want to install the correct i18n functions
+    // here directly instead of first installing the dummy, and overriding those
+    // in i18n.js later.
+    SimpleInstallFunction(prototype, "toLocaleLowerCase",
+                          Builtins::kStringPrototypeToLowerCase, 0, false);
+    SimpleInstallFunction(prototype, "toLocaleUpperCase",
+                          Builtins::kStringPrototypeToUpperCase, 0, false);
+    SimpleInstallFunction(prototype, "toLowerCase",
+                          Builtins::kStringPrototypeToLowerCase, 0, false);
+    SimpleInstallFunction(prototype, "toUpperCase",
+                          Builtins::kStringPrototypeToUpperCase, 0, false);
     SimpleInstallFunction(prototype, "trim", Builtins::kStringPrototypeTrim, 0,
                           false);
     SimpleInstallFunction(prototype, "trimLeft",

src/builtins.cc

@@ -4554,6 +4554,24 @@ void Builtins::Generate_StringPrototypeCharCodeAt(
   assembler->Return(result);
 }
 
+// ES6 section 21.1.3.22 String.prototype.toLowerCase ( )
+BUILTIN(StringPrototypeToLowerCase) {
+  HandleScope scope(isolate);
+  TO_THIS_STRING(string, "String.prototype.toLowerCase");
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, string,
+                                     String::ToLowerCase(string));
+  return *string;
+}
+
+// ES6 section 21.1.3.24 String.prototype.toUpperCase ( )
+BUILTIN(StringPrototypeToUpperCase) {
+  HandleScope scope(isolate);
+  TO_THIS_STRING(string, "String.prototype.toUpperCase");
+  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, string,
+                                     String::ToUpperCase(string));
+  return *string;
+}
+
 // ES6 section 21.1.3.25 String.prototype.trim ()
 BUILTIN(StringPrototypeTrim) {
   HandleScope scope(isolate);

src/builtins.h

@@ -172,6 +172,8 @@ inline bool operator&(BuiltinExtraArguments lhs, BuiltinExtraArguments rhs) {
   V(ReflectSetPrototypeOf, kNone)                              \
                                                                \
   V(StringFromCharCode, kNone)                                 \
+  V(StringPrototypeToLowerCase, kNone)                         \
+  V(StringPrototypeToUpperCase, kNone)                         \
   V(StringPrototypeTrim, kNone)                                \
   V(StringPrototypeTrimLeft, kNone)                            \
   V(StringPrototypeTrimRight, kNone)                           \

src/contexts.h

@@ -84,6 +84,8 @@ enum BindingFlags {
   V(REFLECT_CONSTRUCT_INDEX, JSFunction, reflect_construct)             \
   V(REFLECT_DEFINE_PROPERTY_INDEX, JSFunction, reflect_define_property) \
   V(REFLECT_DELETE_PROPERTY_INDEX, JSFunction, reflect_delete_property) \
+  V(STRING_TO_LOWER_CASE_INDEX, JSFunction, string_to_lower_case)       \
+  V(STRING_TO_UPPER_CASE_INDEX, JSFunction, string_to_upper_case)       \
   V(SPREAD_ARGUMENTS_INDEX, JSFunction, spread_arguments)               \
   V(SPREAD_ITERABLE_INDEX, JSFunction, spread_iterable)                 \
   V(MATH_FLOOR, JSFunction, math_floor)                                 \

src/js/i18n.js

@@ -46,6 +46,8 @@ var StringLastIndexOf;
 var StringSplit;
 var StringSubstr;
 var StringSubstring;
+var StringToLowerCase = GlobalString.prototype.toLowerCase;
+var StringToUpperCase = GlobalString.prototype.toUpperCase;
 
 utils.Import(function(from) {
   ArrayIndexOf = from.ArrayIndexOf;
@@ -693,8 +695,8 @@ function addWECPropertyIfDefined(object, property, value) {
  * Returns titlecased word, aMeRricA -> America.
  */
 function toTitleCaseWord(word) {
-  return %StringToUpperCase(%_Call(StringSubstr, word, 0, 1)) +
-         %StringToLowerCase(%_Call(StringSubstr, word, 1));
+  return %_Call(StringToUpperCase, %_Call(StringSubstr, word, 0, 1)) +
+         %_Call(StringToLowerCase, %_Call(StringSubstr, word, 1));
 }
 
 /**
@@ -715,7 +717,7 @@ function toTitleCaseTimezoneLocation(location) {
     var parts = %_Call(StringSplit, match[2], separator);
     for (var i = 1; i < parts.length; i++) {
       var part = parts[i]
-      var lowercasedPart = %StringToLowerCase(part);
+      var lowercasedPart = %_Call(StringToLowerCase, part);
       result = result + separator +
           ((lowercasedPart !== 'es' &&
             lowercasedPart !== 'of' && lowercasedPart !== 'au') ?
@@ -1155,7 +1157,8 @@ function initializeNumberFormat(numberFormat, locales, options) {
   var currencyDisplay = getOption(
       'currencyDisplay', 'string', ['code', 'symbol', 'name'], 'symbol');
   if (internalOptions.style === 'currency') {
-    defineWEProperty(internalOptions, 'currency', %StringToUpperCase(currency));
+    defineWEProperty(internalOptions, 'currency',
+                     %_Call(StringToUpperCase, currency));
     defineWEProperty(internalOptions, 'currencyDisplay', currencyDisplay);
   }
 
@@ -1789,7 +1792,7 @@ function canonicalizeTimeZoneID(tzID) {
   }
 
   // Special case handling (UTC, GMT).
-  var upperID = %StringToUpperCase(tzID);
+  var upperID = %_Call(StringToUpperCase, tzID);
   if (upperID === 'UTC' || upperID === 'GMT' ||
       upperID === 'ETC/UTC' || upperID === 'ETC/GMT') {
     return 'UTC';

src/js/string.js

@@ -487,38 +487,6 @@ function StringSubstr(start, n) {
 }
 
 
-// ECMA-262, 15.5.4.16
-function StringToLowerCaseJS() {
-  CHECK_OBJECT_COERCIBLE(this, "String.prototype.toLowerCase");
-
-  return %StringToLowerCase(TO_STRING(this));
-}
-
-
-// ECMA-262, 15.5.4.17
-function StringToLocaleLowerCase() {
-  CHECK_OBJECT_COERCIBLE(this, "String.prototype.toLocaleLowerCase");
-
-  return %StringToLowerCase(TO_STRING(this));
-}
-
-
-// ECMA-262, 15.5.4.18
-function StringToUpperCaseJS() {
-  CHECK_OBJECT_COERCIBLE(this, "String.prototype.toUpperCase");
-
-  return %StringToUpperCase(TO_STRING(this));
-}
-
-
-// ECMA-262, 15.5.4.19
-function StringToLocaleUpperCase() {
-  CHECK_OBJECT_COERCIBLE(this, "String.prototype.toLocaleUpperCase");
-
-  return %StringToUpperCase(TO_STRING(this));
-}
-
-
 // ES6 draft, revision 26 (2014-07-18), section B.2.3.2.1
 function HtmlEscape(str) {
   return %_Call(StringReplace, TO_STRING(str), /"/g, """);
@@ -827,10 +795,6 @@ utils.InstallFunctions(GlobalString.prototype, DONT_ENUM, [
   "substring", StringSubstring,
   "substr", StringSubstr,
   "startsWith", StringStartsWith,
-  "toLowerCase", StringToLowerCaseJS,
-  "toLocaleLowerCase", StringToLocaleLowerCase,
-  "toUpperCase", StringToUpperCaseJS,
-  "toLocaleUpperCase", StringToLocaleUpperCase,
 
   "link", StringLink,
   "anchor", StringAnchor,

src/objects.h

@@ -8861,6 +8861,12 @@ class String: public Name {
   // Conversion.
   inline bool AsArrayIndex(uint32_t* index);
 
+  // Case conversion.
+  static MaybeHandle<String> ToLowerCase(Handle<String> string)
+      WARN_UNUSED_RESULT;
+  static MaybeHandle<String> ToUpperCase(Handle<String> string)
+      WARN_UNUSED_RESULT;
+
   // Trimming.
   enum TrimMode { kTrim, kTrimLeft, kTrimRight };
   static Handle<String> Trim(Handle<String> string, TrimMode mode);

src/runtime/runtime.h

@@ -829,8 +829,6 @@ namespace internal {
   F(StringBuilderJoin, 3, 1)              \
   F(SparseJoinWithSeparator, 3, 1)        \
   F(StringToArray, 2, 1)                  \
-  F(StringToLowerCase, 1, 1)              \
-  F(StringToUpperCase, 1, 1)              \
   F(StringLessThan, 2, 1)                 \
   F(StringLessThanOrEqual, 2, 1)          \
   F(StringGreaterThan, 2, 1)              \

test/cctest/interpreter/bytecode_expectations/CallRuntime.golden

@@ -80,7 +80,7 @@ bytecodes: [
   /*   15 S> */ B(LdrUndefined), R(0),
                 B(CreateArrayLiteral), U8(0), U8(0), U8(3),
                 B(Star), R(1),
-                B(CallJSRuntime), U8(122), R(0), U8(2),
+                B(CallJSRuntime), U8(124), R(0), U8(2),
   /*   44 S> */ B(Return),
 ]
 constant pool: [