Changeset 11920 in webkit for trunk/JavaScriptCore/kjs/lookup.cpp

Timestamp:

Jan 6, 2006, 3:51:00 PM (19 years ago)

Author:

mjs

Message:

Reviewed by Darin.

• miscellaneous changes for 4% speedup on the JavaScript iBench ​http://bugzilla.opendarwin.org/show_bug.cgi?id=6396

Changes mostly thanks to Maks Orlovich, tweaked a little by me.

• kjs/create_hash_table: Use the same hash as the one used buy Identifier.
• kjs/function.cpp: (KJS::FunctionImp::processParameters): Use the new List::copyFrom (KJS::ActivationImp::ActivationImp): track variable while iterating
• kjs/internal.cpp: (KJS::StringImp::toObject): create StringInstance directly
• kjs/list.cpp: (KJS::List::copy): implement in terms of copyFrom (KJS::List::copyFrom): more efficient way to copy in another list
• kjs/list.h:
• kjs/lookup.cpp: (keysMatch): updated to work with identifier hash (findEntry): ditto (Lookup::findEntry): ditto (Lookup::find): ditto
• kjs/lookup.h:

File:

• trunk/JavaScriptCore/kjs/lookup.cpp (modified) (6 diffs)

trunk/JavaScriptCore/kjs/lookup.cpp

@@ -34 +34 @@
 static inline bool keysMatch(const UChar *c, unsigned len, const char *s)
 {
-  for (unsigned i = 0; i != len; i++, c++, s++)
+  const char* end = s + len;
+  for (; s != end; c++, s++)
     if (c->uc != (unsigned char)*s)
       return false;
@@ -40 +41 @@
 }
 
-const HashEntry* Lookup::findEntry( const struct HashTable *table,
-                              const UChar *c, unsigned int len )
+static inline const HashEntry* findEntry(const struct HashTable *table, unsigned int hash,
+                                         const UChar *c, unsigned int len )
 {
 #ifndef NDEBUG
@@ -49 +50 @@
   }
 #endif
-
-  int h = hash(c, len) % table->hashSize;
-  const HashEntry *e = &table->entries[h];
+  hash %= table->hashSize;
+  const HashEntry *e = &table->entries[hash];
 
   // empty bucket ?
@@ -61 +61 @@
     if (keysMatch(c, len, e->s))
       return e;
+
     // try next bucket
     e = e->next;
   } while (e);
-
   return 0;
 }
 
-const HashEntry* Lookup::findEntry( const struct HashTable *table,
-                                const Identifier &s )
+const HashEntry* Lookup::findEntry(const struct HashTable *table,
+                                   const Identifier &s )
 {
-  return findEntry( table, s.data(), s.size() );
+  const HashEntry* entry = ::findEntry(table, s.ustring().rep()->hash(), s.data(), s.size());
+  return entry;
 }
 
@@ -77 +78 @@
                  const UChar *c, unsigned int len)
 {
-  const HashEntry *entry = findEntry( table, c, len );
+  const HashEntry *entry = ::findEntry(table, UString::Rep::computeHash(c, len), c, len);
   if (entry)
     return entry->value;
@@ -85 +86 @@
 int Lookup::find(const struct HashTable *table, const Identifier &s)
 {
-  return find(table, s.data(), s.size());
+  //printf("looking for:%s\n", s.ascii());
+  const HashEntry *entry = ::findEntry(table, s.ustring().rep()->hash(), s.data(), s.size());
+  if (entry)
+    return entry->value;
+  return -1;
 }
-
-unsigned int Lookup::hash(const UChar *c, unsigned int len)
-{
-  unsigned int val = 0;
-  // ignoring higher byte
-  for (unsigned int i = 0; i < len; i++, c++)
-    val += c->low();
-
-  return val;
-}
-
-unsigned int Lookup::hash(const Identifier &key)
-{
-  return hash(key.data(), key.size());
-}
-
-unsigned int Lookup::hash(const char *s)
-{
-  unsigned int val = 0;
-  while (*s)
-    val += *s++;
-
-  return val;
-}