JavaScriptCore:
2008-04-25 Darin Adler <Darin Adler>
Reviewed by Maciej.
- fix <rdar://problem/5657459> REGRESSION: JavaScriptCore no longer builds with
GCC 4.2 due to pointer aliasing warnings
Fix this by removing the HashTable optimizations that allowed us to share a back end
implementation between hash tables with integers, pointers, RefPtr, and String objects
as keys. The way it worked was incompatible with strict aliasing.
This increases code size. On Mac OS X we'll have to regenerate .order files to avoid
slowing down Safari startup times.
This creates a slight slowdown in SunSpider, mitigated by the following four speedups:
- speed up array put slightly by moving a branch (was already done for get)
- speed up symbol table access by adding a function named inlineGet to HashMap
and using that in symbolTableGet/Put
- speed up PropertyNameArray creation by reducing the amount of reference count
churn and uniqueness checking when adding names and not doing any allocation at
all when building small arrays
- speed up conversion of strings to floating point numbers by eliminating the
malloc/free of the buffer for the ASCII copy of the string; a way to make
things even faster would be to change strtod to take a UTF-16 string
Note that there is considerable unused complexity now in HashSet/Map/Table to support
"storage types", which is no longer used. Will do in a separate patch.
- API/JSCallbackObjectFunctions.h:
(KJS::JSCallbackObject<Base>::getPropertyNames): Removed explicit cast to Identifier to
take advantage of the new PropertyNameArray::add overload and avoid reference count churn.
- API/JSObjectRef.cpp:
(JSPropertyNameAccumulatorAddName): Ditto.
- JavaScriptCore.exp: Updated PropertyNameArray::add entry point name.
- kjs/JSVariableObject.cpp: Removed now-unneeded IdentifierRepHashTraits::nullRepPtr
definition (see below).
(KJS::JSVariableObject::getPropertyNames): Removed explicit cast to Identifier.
- kjs/JSVariableObject.h:
(KJS::JSVariableObject::symbolTableGet): Use inlineGet for speed. Also changed to do
early exit instead of nesting the body inside an if.
(KJS::JSVariableObject::symbolTablePut): Ditto.
- kjs/PropertyNameArray.cpp:
(KJS::PropertyNameArray::add): Changed implementation to take a raw pointer instead of
a reference to an identifier. Do uniqueness checking by searching the vector when the
vector is short, only building the set once the vector is large enough.
- kjs/PropertyNameArray.h: Added an overload of add for a raw pointer, and made the old
add function call that one. Added an addKnownUnique function for use when the new
name is known to be different from any other in the array. Changed the vector to have
an inline capacity of 20.
- kjs/SymbolTable.h: Changed IdentifierRepHash to inherit from the default hash for
a RefPtr so we don't have to define so much. Added an overload of the hash function for
a raw pointer as required by the new RefPtrHashMap. Got rid of the now-unneeded
IdentifierRepHashTraits -- the default traits now work fine. Added a definition of
empthValueIsZero to SymbolTableIndexHashTraits; not having it was incorrect, but harmless.
- kjs/array_instance.cpp:
(KJS::ArrayInstance::put): Move the maxArrayIndex check inside the branch that checks
the index against the length, as done in the get function.
- kjs/function.cpp:
(KJS::globalFuncKJSPrint): Changed to use the new getCString instead of cstring.
- kjs/internal.cpp: Removed printInfo debugging function, a client of cstring.
If we need a debugging function we can easily make a better one and we haven't
used this one in a long time.
- kjs/internal.h: Ditto.
- kjs/object.cpp:
(KJS::JSObject::getPropertyNames): Removed explicit cast to Identifier.
- kjs/property_map.cpp:
(KJS::PropertyMap::getEnumerablePropertyNames): Ditto. Also added a special case for
the case where the propertyNames array is empty -- in that case we know we're adding
a set of names that are non-overlapping so we can use addKnownUnique.
- kjs/ustring.cpp:
(KJS::UString::getCString): Replaces cstring. Puts the C string into a CStringBuffer,
which is a char Vector with an inline capacity. Also returns a boolean to indicate if
the converion was lossy, which eliminates the need for a separate is8Bit call.
(KJS::UString::toDouble): Changed to call getCString instead of cstring.
- kjs/ustring.h: Ditto.
- wtf/HashFunctions.h: Overload the hash and equal functions for RefPtr's default
hash to take raw pointers. This works with the changes to RefPtrHashMap to avoid
introducing refcount churn.
- wtf/HashMap.h: Removed special code to convert the deleted value to the empty value
when writing a new value into the map. This is now handled elsewhere.
(WTF::HashMap::get): Removed code that checks for an empty hash table before calling
HashTable::lookup; it's slightly more efficient to do this check inside lookup.
- wtf/HashTable.h:
(WTF::HashTable::isDeletedBucket): Changed to use isDeletedValue instead of using
deletedValue and the equality operator.
(WTF::HashTable::deleteBucket): Changed to use constructDeletedValue instead of
using deletedValue and the assignment operator.
(WTF::HashTable::checkKey): Added. Factors out the check for values that are empty
or deleted keys that's used in various functions below.
(WTF::HashTable::lookup): Changed to use checkKey, check for a 0 table, and also
made public for use by RefPtrHashMap.
(WTF::HashTable::lookupForWriting): Changed to use checkKey.
(WTF::HashTable::fullLookupForWriting): Changed to use checkKey.
(WTF::HashTable::add): Changed to use checkKey, and call initializeBucket on a
deleted bucket before putting a new entry into it.
(WTF::HashTable::addPassingHashCode): Ditto.
(WTF::HashTable::deallocateTable): Check isDeletedBucket before calling ~ValueType.
- wtf/HashTraits.h: Got ridd of all the HashTraits specialization for the integer
types, since GeneicHashTraitsBase already deals with integers separately. Put the
deleted value support into GenericHashTraitsBase. Changed FloatHashTraits to
inherit from GenericHashTraits, and define construct/isDeletedValue rather than
deletedValue. Removed the ref and deref functions from RefPtr's HashTraits, and
defined construct/isDeletedValue. Eliminated DeletedValueAssigner. Changed
PairHashTraits to define construct/isDeletedValue, and also merged
PairBaseHashTraits in with PairHashTraits. Got rid of all specialization of
HashKeyStorageTraits. We'll remove that, and the needsRef data member, later.
- wtf/RefPtr.h: Added HashTableDeletedValueType, an enum type with a single value,
HashTableDeletedValue. Used that type to make a new constructor to construct
deleted values and also added an isHashTableDeletedValue function.
- wtf/RefPtrHashMap.h: Added RefPtrHashMapRawKeyTranslator and used it to implement
the raw pointer functions. This is a way to continue to avoid refcount thrash. We
can't use the old way because it depended on the underlying map using a non-RefPtr
type.
(WTF::HashMap::find): Use find with RefPtrHashMapRawKeyTranslator.
(WTF::HashMap::contains): Use contains with RefPtrHashMapRawKeyTranslator.
(WTF::HashMap::inlineAdd): Use add with RefPtrHashMapRawKeyTranslator.
(WTF::HashMap::get): Removed code that checks for an empty hash table before calling
HashTable::lookup; it's slightly more efficient to do this check inside lookup.
(WTF::HashMap::inlineGet): Added. Just like get, but marked inline for use in the
symbol table code.
WebCore:
2008-04-25 Darin Adler <Darin Adler>
Reviewed by Maciej.
- update for compatibility with HashTable that no longer has optimization to share
implementation between hash tables with integers, pointers, RefPtr, and String
objects as keys
- bindings/js/JSSVGPODTypeWrapper.h:
(WebCore::PODTypeReadWriteHashInfo::PODTypeReadWriteHashInfo): Added constructor
for HashTableDeletedValue.
(WebCore::PODTypeReadWriteHashInfo::isHashTableDeletedValue): Added.
(WebCore::PODTypeReadWriteHashInfoTraits::constructDeletedValue): Added.
(WebCore::PODTypeReadWriteHashInfoTraits::isDeletedValue): Added.
- dom/Document.cpp: Made changedDocuments internal to the file rather than a
static data member of Document.
(WebCore::FormElementKey::ref): Removed unneeded check for deleted value -- this
will never be called on a deleted element.
(WebCore::FormElementKey::deref): Ditto.
- dom/Document.h: Added HashTableDeletedValue constructor and isHashTableDeletedValue
to FormElementKey. Changed FormElementKeyHashTraits to use construct/isDeletedValue.
Got rid of the changedDocuments data member. Changed iconURL to be an inline that
returns a const String&.
- dom/StyledElement.cpp: Changed MappedAttributeKeyTraits to use
construct/isDeletedValue.
- page/mac/AXObjectCacheMac.mm:
(WebCore::AXObjectCache::getAXID): Call isDeletedValue instead of deletedValue.
- platform/SecurityOriginHash.h: Added overload so that SecurityOriginHash can work
with raw pointers as well as RefPt (helpful with the new RefPtrHashMap). Eliminated
SecurityOriginTraits, since we can now use the default traits. Changed the value of
safeToCompareToEmptyOrDeleted to false, since it's not safe to compare a deleted
value using this hash function. I don't think it was safe before either; I'm not sure
why it didn't cause a problem before.
- platform/cf/SchedulePair.h: Removed SchedulePairTraits -- custom traits are no
longer needed.
- platform/graphics/FontCache.cpp:
(WebCore::FontPlatformDataCacheKey::FontPlatformDataCacheKey): Added constructor
for HashTableDeletedValue.
(WebCore::FontPlatformDataCacheKey::isHashTableDeletedValue): Added.
(WebCore::FontPlatformDataCacheKey::hashTableDeletedSize): Added.
(WebCore::FontPlatformDataCacheKeyTraits::constructDeletedValue): Added.
(WebCore::FontPlatformDataCacheKeyTraits::isDeletedValue): Added.
(WebCore::FontDataCacheKeyTraits::constructDeletedValue): Added.
(WebCore::FontDataCacheKeyTraits::isDeletedValue): Added.
- platform/graphics/IntSizeHash.h: Changed HashTraits<IntSize> to use
construct/isDeletedValue.
- platform/graphics/mac/FontPlatformData.h:
(WebCore::FontPlatformData::FontPlatformData): Added constructor for
HashTableDeletedValue.
(WebCore::FontPlatformData::isHashTableDeletedValue): Added.
(WebCore::FontPlatformData::hashTableDeletedFontValue): Added.
- platform/text/PlatformString.h:
(WebCore::String::swap): Added. Avoids any refcount churn when swapping two strings.
(WebCore::String::String): Added constructor for HashTableDeletedValue.
(WebCore::String::isHashTableDeletedValue): Added.
(WebCore::swap): Added. Avoids any refcount churn when swapping two strings.
- platform/text/StringHash.h: Changed specialization of HashTraits for
WebCore::String to use the deleted value now defined in that class and removed
the code to do ref/deref. Removed HashKeyStorageTraits specializations.
- platform/win/COMPtr.h: Changed specialization of HashTraits for
COMPtr to use the deleted value now defined in that class and removed
the code to do ref/deref. Removed HashKeyStorageTraits specializations.
(COMPtr::COMPtr): Added constructor for HashTableDeletedValue.
(COMPtr::isHashTableDeletedValue): Added.
(COMPtr::query): Removed inline keyword not needed since functions defined in the
class definition are automatically marked inline.
(COMPtr::hashTableDeletedValue): Added.
- storage/DatabaseTracker.h: Removed now-unneeded SecurityOriginTraits.
- storage/LocalStorage.h: Ditto.
- storage/OriginQuotaManager.h: Ditto.
- storage/SessionStorage.h: Ditto.
- svg/SVGAnimatedTemplate.h:
(WebCore::SVGAnimatedTypeWrapperKey::SVGAnimatedTypeWrapperKey): Added constructor
for HashTableDeletedValue.
(WebCore::SVGAnimatedTypeWrapperKey::isHashTableDeletedValue): Added.
(WebCore::SVGAnimatedTypeWrapperKeyHashTraits::constructDeletedValue): Added.
(WebCore::SVGAnimatedTypeWrapperKeyHashTraits::isDeletedValue): Added.
