Remove regexp caching.

src/string.js

Index: src/string.js
diff --git a/src/string.js b/src/string.js
index d97f632b88dc32975830ecc2f50186199c1768ce..a75ccf0fa54f0747223e7be60845cfbd6af95d95 100644
--- a/src/string.js
+++ b/src/string.js
@@ -144,16 +144,6 @@ function StringLastIndexOf(searchString /* position */) {  // length == 1
 }
 
 
-function CloneDenseArray(array) {
-  if (array === null) return null;
-  var clone = new $Array(array.length);
-  for (var i = 0; i < array.length; i++) {
-    clone[i] = array[i];
-  }
-  return clone;
-}
-
-
 // ECMA-262 section 15.5.4.9
 //
 // This function is implementation specific.  For now, we do not
@@ -173,32 +163,14 @@ function StringMatch(regexp) {
   if (IS_REGEXP(regexp)) {
     if (!regexp.global) return regexp.exec(subject);
 
-    var cache = regExpCache;
     var saveAnswer = false;
 
-    if (%_ObjectEquals(cache.type, 'match') &&
-        %_IsRegExpEquivalent(cache.regExp, regexp) &&
-        %_ObjectEquals(cache.subject, subject)) {
-      if (cache.answerSaved) {
-        return CloneDenseArray(cache.answer);
-      } else {
-        saveAnswer = true;
-      }
-    }
     %_Log('regexp', 'regexp-match,%0S,%1r', [subject, regexp]);
     // lastMatchInfo is defined in regexp.js.
-    var result = %StringMatch(subject, regexp, lastMatchInfo);
-    cache.type = 'match';
-    cache.regExp = regexp;
-    cache.subject = subject;
-    if (saveAnswer) cache.answer = CloneDenseArray(result);
-    cache.answerSaved = saveAnswer;
-    return result;
+    return %StringMatch(subject, regexp, lastMatchInfo);
   }
   // Non-regexp argument.
   regexp = new $RegExp(regexp);
-  // Don't check regexp exec cache, since the regexp is new.
-  // TODO(lrn): Change this if we start caching regexps here.
   return RegExpExecNoTests(regexp, subject, 0);
 }
 
@@ -231,7 +203,6 @@ function StringReplace(search, replace) {
   if (IS_REGEXP(search)) {
     %_Log('regexp', 'regexp-replace,%0r,%1S', [search, subject]);
     if (IS_FUNCTION(replace)) {
-      regExpCache.type = 'none';
       if (search.global) {
         return StringReplaceGlobalRegExpWithFunction(subject, search, replace);
       } else {
@@ -273,24 +244,10 @@ function StringReplace(search, replace) {
 
 // Helper function for regular expressions in String.prototype.replace.
 function StringReplaceRegExp(subject, regexp, replace) {
-  var cache = regExpCache;
-  if (%_ObjectEquals(cache.type, 'replace') &&
-      %_IsRegExpEquivalent(cache.regExp, regexp) &&
-      %_ObjectEquals(cache.replaceString, replace) &&
-      %_ObjectEquals(cache.subject, subject)) {
-    return cache.answer;
-  }
-  replace = TO_STRING_INLINE(replace);
-  var answer = %StringReplaceRegExpWithString(subject,
-                                              regexp,
-                                              replace,
-                                              lastMatchInfo);
-  cache.subject = subject;
-  cache.regExp = regexp;
-  cache.replaceString = replace;
-  cache.answer = answer;
-  cache.type = 'replace';
-  return answer;
+  return %StringReplaceRegExpWithString(subject,
+                                        regexp,
+                                        TO_STRING_INLINE(replace),
+                                        lastMatchInfo);
 }
 
 
@@ -605,34 +562,14 @@ function StringSplit(separator, limit) {
     return result;
   }
 
-  var cache = regExpCache;
   var saveAnswer = false;
 
-  if (%_ObjectEquals(cache.type, 'split') &&
-      %_IsRegExpEquivalent(cache.regExp, separator) &&
-      %_ObjectEquals(cache.subject, subject) &&
-      %_ObjectEquals(cache.splitLimit, limit)) {
-    if (cache.answerSaved) {
-      return CloneDenseArray(cache.answer);
-    } else {
-      saveAnswer = true;
-    }
-  }
-
-  cache.type = 'split';
-  cache.regExp = separator;
-  cache.subject = subject;
-  cache.splitLimit = limit;
-
   %_Log('regexp', 'regexp-split,%0S,%1r', [subject, separator]);
 
   if (length === 0) {
-    cache.answerSaved = true;
     if (splitMatch(separator, subject, 0, 0) != null) {
-      cache.answer = [];
       return [];
     }
-    cache.answer = [subject];
     return [subject];
   }
 
@@ -680,8 +617,6 @@ function StringSplit(separator, limit) {
 
     startIndex = currentIndex = endIndex;
   }
-  if (saveAnswer) cache.answer = CloneDenseArray(result);
-  cache.answerSaved = saveAnswer;
   return result;
 }