Changeset 42606 in webkit for trunk/JavaScriptCore/runtime/Lookup.h

Timestamp:

Apr 16, 2009, 11:20:32 PM (16 years ago)

Author:

Stephanie Lewis

Message:

2009-04-16 Stephanie Lewis <Stephanie Lewis>

Reviewed by Oliver Hunt.

<rdar://problem/6744652> 32-bit to 64-bit: Javascript hash tables double in size

Remove perfect hash optimization which removes 1 MB of overhead on 32-bit and almost 2 MB on 64-bit. Removing the optimization was not a regression on SunSpider and the acid 3 test still passes.

• create_hash_table:
• runtime/Lookup.cpp: (JSC::HashTable::createTable): (JSC::HashTable::deleteTable):
• runtime/Lookup.h: (JSC::HashEntry::initialize): (JSC::HashEntry::next): (JSC::HashTable::entry):
• runtime/Structure.cpp: (JSC::Structure::getEnumerableNamesFromClassInfoTable):

File:

• trunk/JavaScriptCore/runtime/Lookup.h (modified) (6 diffs)

trunk/JavaScriptCore/runtime/Lookup.h

@@ -31 +31 @@
 #include <wtf/Assertions.h>
 
-// Set ENABLE_PERFECT_HASH_SIZE to 0 to save memory at the
-// cost of speed.  Test your platform as results may vary.
-#define ENABLE_PERFECT_HASH_SIZE 1
-
 namespace JSC {
 
@@ -58 +54 @@
             m_u.store.value1 = v1;
             m_u.store.value2 = v2;
-#if !ENABLE(PERFECT_HASH_SIZE)
             m_next = 0;
-#endif
         }
 
@@ -76 +70 @@
         intptr_t lexerValue() const { ASSERT(!m_attributes); return m_u.lexer.value; }
 
-#if !ENABLE(PERFECT_HASH_SIZE)
         void setNext(HashEntry *next) { m_next = next; }
         HashEntry* next() const { return m_next; }
-#endif
 
     private:
@@ -104 +96 @@
         } m_u;
 
-#if !ENABLE(PERFECT_HASH_SIZE)
         HashEntry* m_next;
-#endif
     };
 
     struct HashTable {
-#if ENABLE(PERFECT_HASH_SIZE)
-        int hashSizeMask; // Precomputed size for the hash table (minus 1).
-#else
+
         int compactSize;
         int compactHashSizeMask;
-#endif
+
         const HashTableValue* values; // Fixed values generated by script.
         mutable const HashEntry* table; // Table allocated at runtime.
@@ -149 +137 @@
         ALWAYS_INLINE const HashEntry* entry(const Identifier& identifier) const
         {
-#if ENABLE(PERFECT_HASH_SIZE)
-            ASSERT(table);
-            const HashEntry* entry = &table[identifier.ustring().rep()->computedHash() & hashSizeMask];
-            if (entry->key() != identifier.ustring().rep())
-                return 0;
-            return entry;
-#else
             ASSERT(table);
 
@@ -170 +151 @@
 
             return 0;
-#endif
         }