Changeset 36124 in webkit for trunk/JavaScriptCore/kjs/SmallStrings.cpp

Timestamp:

Sep 5, 2008, 9:58:40 PM (17 years ago)

Author:

Darin Adler

Message:

2008-09-05 Darin Adler <Darin Adler>

Reviewed by Geoff Garen.

• fix ​https://bugs.webkit.org/show_bug.cgi?id=20673 single-character strings are churning in the Identifier table

1.007x as fast on SunSpider overall
1.167x as fast on SunSpider string/fasta

• JavaScriptCore.exp: Updated.
• kjs/SmallStrings.cpp: (KJS::SmallStrings::singleCharacterStringRep): Added.
• kjs/SmallStrings.h: Added singleCharacterStringRep for clients that need just a UString, not a JSString.
• kjs/identifier.cpp: (KJS::Identifier::add): Added special cases for single character strings so that the UString::Rep that ends up in the identifier table is the one from the single-character string optimization; otherwise we end up having to look it up in the identifier table over and over again. (KJS::Identifier::addSlowCase): Ditto. (KJS::Identifier::checkSameIdentifierTable): Made this function an empty inline in release builds so that callers don't have to put #ifndef NDEBUG at each call site.
• kjs/identifier.h: (KJS::Identifier::add): Removed #ifndef NDEBUG around the calls to checkSameIdentifierTable. (KJS::Identifier::checkSameIdentifierTable): Added. Empty inline version for NDEBUG builds.

File:

• trunk/JavaScriptCore/kjs/SmallStrings.cpp (modified) (1 diff)

trunk/JavaScriptCore/kjs/SmallStrings.cpp

@@ -102 +102 @@
 }
 
+UString::Rep* SmallStrings::singleCharacterStringRep(unsigned char character)
+{
+    if (!m_storage)
+        m_storage.set(new SmallStringsStorage);
+    return m_storage->rep(character);
 }
+
+}