var numResults = NUMBER_OF_CAPTURES(MATCHINFO) >> 1;
var start = MATCHINFO[CAPTURE0];
var end = MATCHINFO[CAPTURE1];
+ // Calculate the substring of the first match before creating the result array
+ // to avoid an unnecessary write barrier storing the first result.
+ var first = %_SubString(STRING, start, end);
var result = %_RegExpConstructResult(numResults, start, STRING);
- result[0] = %_SubString(STRING, start, end);
+ result[0] = first;
+ if (numResults == 1) return result;
var j = REGEXP_FIRST_CAPTURE + 2;
for (var i = 1; i < numResults; i++) {
start = MATCHINFO[j++];
}
-var ArrayPushBuiltin = $Array.prototype.push;
-
function StringSplitOnRegExp(subject, separator, limit, length) {
if (length === 0) {
if (DoRegExpExec(separator, subject, 0, 0) != null) {
while (true) {
if (startIndex === length) {
- %_CallFunction(result, %_SubString(subject, currentIndex, length),
- ArrayPushBuiltin);
+ result[result.length] = %_SubString(subject, currentIndex, length);
break;
}
var matchInfo = DoRegExpExec(separator, subject, startIndex);
if (matchInfo == null || length === (startMatch = matchInfo[CAPTURE0])) {
- %_CallFunction(result, %_SubString(subject, currentIndex, length),
- ArrayPushBuiltin);
+ result[result.length] = %_SubString(subject, currentIndex, length);
break;
}
var endIndex = matchInfo[CAPTURE1];
continue;
}
- %_CallFunction(result, %_SubString(subject, currentIndex, startMatch),
- ArrayPushBuiltin);
+ result[result.length] = %_SubString(subject, currentIndex, startMatch);
if (result.length === limit) break;
var start = matchInfo[i++];
var end = matchInfo[i++];
if (end != -1) {
- %_CallFunction(result, %_SubString(subject, start, end),
- ArrayPushBuiltin);
+ result[result.length] = %_SubString(subject, start, end);
} else {
- %_CallFunction(result, UNDEFINED, ArrayPushBuiltin);
+ result[result.length] = UNDEFINED;
}
if (result.length === limit) break outer_loop;
}