Changeset 101187 in webkit

Timestamp:

Nov 25, 2011, 10:15:20 PM (15 years ago)

Author:

msaboff@apple.com

Message:

String.prototype.toLower should be optimized for 8 bit strings
​https://bugs.webkit.org/show_bug.cgi?id=73154

Changed stringProtoFuncToLowerCase to use StringImpl::lower() which has
been optimized for 8 bit strings.

This is worth ~7% to sunspider string.tagcloud.

Reviewed by Filip Pizlo.

• runtime/StringPrototype.cpp:

(JSC::stringProtoFuncToLowerCase):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• runtime/StringPrototype.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2011-11-25  Michael Saboff  <msaboff@apple.com>
+
+        String.prototype.toLower should be optimized for 8 bit strings
+        https://bugs.webkit.org/show_bug.cgi?id=73154
+
+        Changed stringProtoFuncToLowerCase to use StringImpl::lower() which has
+        been optimized for 8 bit strings.
+
+        This is worth ~7% to sunspider string.tagcloud.
+
+        Reviewed by Filip Pizlo.
+
+        * runtime/StringPrototype.cpp:
+        (JSC::stringProtoFuncToLowerCase):
+
 2011-11-25  Michael Saboff  <msaboff@apple.com>
 

trunk/Source/JavaScriptCore/runtime/StringPrototype.cpp

@@ -1190 +1190 @@
         return JSValue::encode(sVal);
 
-    const UChar* sData = s.characters();
-    Vector<UChar> buffer(sSize);
-
-    UChar ored = 0;
-    for (int i = 0; i < sSize; i++) {
-        UChar c = sData[i];
-        ored |= c;
-        buffer[i] = toASCIILower(c);
-    }
-    if (!(ored & ~0x7f))
-        return JSValue::encode(jsString(exec, UString::adopt(buffer)));
-
-    bool error;
-    int length = Unicode::toLower(buffer.data(), sSize, sData, sSize, &error);
-    if (error) {
-        buffer.resize(length);
-        length = Unicode::toLower(buffer.data(), length, sData, sSize, &error);
-        if (error)
-            return JSValue::encode(sVal);
-    }
-    if (length == sSize) {
-        if (memcmp(buffer.data(), sData, length * sizeof(UChar)) == 0)
-            return JSValue::encode(sVal);
-    } else
-        buffer.resize(length);
-    return JSValue::encode(jsString(exec, UString::adopt(buffer)));
+    return JSValue::encode(jsString(exec, UString(s.impl()->lower())));
 }