Cleanup latin-1 conversion check in regexp engine

src/jsregexp.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 2857 matching lines @@
       for (int j = 0; j < quarks.length(); j++) {
 #ifndef ENABLE_LATIN_1
         if (quarks[j] > String::kMaxOneByteCharCode) {
           return set_replacement(NULL);
         }
 #else
         if (quarks[j] <= String::kMaxOneByteCharCode) continue;
         if (!ignore_case) return set_replacement(NULL);
         // Here, we need to check for characters whose upper and lower cases
         // are outside the Latin-1 range.
-        // TODO(dcarney): Replace this code with a simple
-        // table lookup in unibrow::Latin-1.
-        // TODO(dcarney): Test cases!.
-        unibrow::uchar result;
-        int chars;
-        chars = unibrow::ToLowercase::Convert(quarks[j], 0, &result, NULL);
-        if (chars > 1 ||
-            (chars == 1 && result <= String::kMaxOneByteCharCodeU)) {
-          continue;
+        if (!unibrow::Latin1::NonLatin1CanBeConvertedToLatin1(quarks[j])) {
+          return set_replacement(NULL);
         }
-        chars = unibrow::ToUppercase::Convert(quarks[j], 0, &result, NULL);
-        if (chars > 1 ||
-            (chars == 1 && result <= String::kMaxOneByteCharCodeU)) {
-          continue;
-        }
-        // This character is definitely not in the Latin-1 range.
-        return set_replacement(NULL);
 #endif
       }
     } else {
       ASSERT(elm.type == TextElement::CHAR_CLASS);
 #ifdef ENABLE_LATIN_1
       // TODO(dcarney): Can this be improved?
       if (ignore_case) continue;
 #endif
       RegExpCharacterClass* cc = elm.data.u_char_class;
       ZoneList<CharacterRange>* ranges = cc->ranges(zone());
@@ skipping 3288 matching lines @@
   }
 
   return compiler.Assemble(&macro_assembler,
                            node,
                            data->capture_count,
                            pattern);
 }
 
 
 }}  // namespace v8::internal