Modified: trunk/Source/_javascript_Core/ChangeLog (141294 => 141295)
--- trunk/Source/_javascript_Core/ChangeLog 2013-01-30 20:03:24 UTC (rev 141294)
+++ trunk/Source/_javascript_Core/ChangeLog 2013-01-30 20:05:14 UTC (rev 141295)
@@ -1,3 +1,26 @@
+2013-01-29 Mark Hahnenberg <mhahnenb...@apple.com>
+
+ Structure::m_outOfLineCapacity is unnecessary
+ https://bugs.webkit.org/show_bug.cgi?id=108206
+
+ Reviewed by Geoffrey Garen.
+
+ We can calculate our out of line capacity by using the outOfLineSize and our knowledge about our resize policy.
+ According to GDB, this knocks Structures down from 136 bytes to 128 bytes (I'm guessing the extra bytes are from
+ better alignment of object fields), which puts Structures in a smaller size class. Woohoo! Looks neutral on our
+ benchmarks.
+
+ * runtime/Structure.cpp:
+ (JSC::Structure::Structure):
+ (JSC):
+ (JSC::Structure::suggestedNewOutOfLineStorageCapacity):
+ (JSC::Structure::addPropertyTransition):
+ (JSC::Structure::addPropertyWithoutTransition):
+ * runtime/Structure.h:
+ (Structure):
+ (JSC::Structure::outOfLineCapacity):
+ (JSC::Structure::totalStorageCapacity):
+
2013-01-29 Geoffrey Garen <gga...@apple.com>
Be a little more conservative about emitting table-based switches
Modified: trunk/Source/_javascript_Core/runtime/Structure.cpp (141294 => 141295)
--- trunk/Source/_javascript_Core/runtime/Structure.cpp 2013-01-30 20:03:24 UTC (rev 141294)
+++ trunk/Source/_javascript_Core/runtime/Structure.cpp 2013-01-30 20:05:14 UTC (rev 141295)
@@ -157,7 +157,6 @@
, m_prototype(globalData, this, prototype)
, m_classInfo(classInfo)
, m_transitionWatchpointSet(InitializedWatching)
- , m_outOfLineCapacity(0)
, m_inlineCapacity(inlineCapacity)
, m_offset(invalidOffset)
, m_dictionaryKind(NoneDictionaryKind)
@@ -184,7 +183,6 @@
, m_prototype(globalData, this, jsNull())
, m_classInfo(&s_info)
, m_transitionWatchpointSet(InitializedWatching)
- , m_outOfLineCapacity(0)
, m_inlineCapacity(0)
, m_offset(invalidOffset)
, m_dictionaryKind(NoneDictionaryKind)
@@ -207,7 +205,6 @@
, m_prototype(globalData, this, previous->storedPrototype())
, m_classInfo(previous->m_classInfo)
, m_transitionWatchpointSet(InitializedWatching)
- , m_outOfLineCapacity(previous->m_outOfLineCapacity)
, m_inlineCapacity(previous->m_inlineCapacity)
, m_offset(invalidOffset)
, m_dictionaryKind(previous->m_dictionaryKind)
@@ -273,14 +270,9 @@
return currentCapacity * outOfLineGrowthFactor;
}
-void Structure::growOutOfLineCapacity()
-{
- m_outOfLineCapacity = nextOutOfLineStorageCapacity(m_outOfLineCapacity);
-}
-
size_t Structure::suggestedNewOutOfLineStorageCapacity()
{
- return nextOutOfLineStorageCapacity(m_outOfLineCapacity);
+ return nextOutOfLineStorageCapacity(outOfLineCapacity());
}
void Structure::despecifyDictionaryFunction(JSGlobalData& globalData, PropertyName propertyName)
@@ -365,8 +357,6 @@
Structure* transition = toCacheableDictionaryTransition(globalData, structure);
ASSERT(structure != transition);
offset = transition->putSpecificValue(globalData, propertyName, attributes, specificValue);
- if (transition->outOfLineSize() > transition->outOfLineCapacity())
- transition->growOutOfLineCapacity();
return transition;
}
@@ -391,8 +381,6 @@
}
offset = transition->putSpecificValue(globalData, propertyName, attributes, specificValue);
- if (transition->outOfLineSize() > transition->outOfLineCapacity())
- transition->growOutOfLineCapacity();
transition->m_offset = offset;
checkOffset(transition->m_offset, transition->inlineCapacity());
@@ -664,10 +652,7 @@
pin();
- PropertyOffset offset = putSpecificValue(globalData, propertyName, attributes, specificValue);
- if (outOfLineSize() > outOfLineCapacity())
- growOutOfLineCapacity();
- return offset;
+ return putSpecificValue(globalData, propertyName, attributes, specificValue);
}
PropertyOffset Structure::removePropertyWithoutTransition(JSGlobalData& globalData, PropertyName propertyName)
Modified: trunk/Source/_javascript_Core/runtime/Structure.h (141294 => 141295)
--- trunk/Source/_javascript_Core/runtime/Structure.h 2013-01-30 20:03:24 UTC (rev 141294)
+++ trunk/Source/_javascript_Core/runtime/Structure.h 2013-01-30 20:05:14 UTC (rev 141295)
@@ -182,11 +182,18 @@
}
bool transitivelyTransitionedFrom(Structure* structureToFind);
- void growOutOfLineCapacity();
unsigned outOfLineCapacity() const
{
- ASSERT(structure()->classInfo() == &s_info);
- return m_outOfLineCapacity;
+ unsigned outOfLineSize = this->outOfLineSize();
+
+ if (!outOfLineSize)
+ return 0;
+
+ if (outOfLineSize <= initialOutOfLineCapacity)
+ return initialOutOfLineCapacity;
+
+ ASSERT(outOfLineSize > initialOutOfLineCapacity);
+ return WTF::roundUpToPowerOf<outOfLineGrowthFactor>(outOfLineSize);
}
unsigned outOfLineSize() const
{
@@ -226,7 +233,7 @@
unsigned totalStorageCapacity() const
{
ASSERT(structure()->classInfo() == &s_info);
- return m_outOfLineCapacity + inlineCapacity();
+ return outOfLineCapacity() + inlineCapacity();
}
PropertyOffset firstValidOffset() const
@@ -435,7 +442,6 @@
mutable InlineWatchpointSet m_transitionWatchpointSet;
- uint32_t m_outOfLineCapacity;
uint8_t m_inlineCapacity;
COMPILE_ASSERT(firstOutOfLineOffset < 256, firstOutOfLineOffset_fits);
Modified: trunk/Source/WTF/wtf/MathExtras.h (141294 => 141295)
--- trunk/Source/WTF/wtf/MathExtras.h 2013-01-30 20:03:24 UTC (rev 141294)
+++ trunk/Source/WTF/wtf/MathExtras.h 2013-01-30 20:05:14 UTC (rev 141295)
@@ -429,4 +429,30 @@
}
}
+namespace WTF {
+
+// Be careful, this might be super slow in a hot loop.
+template<size_t exponent> inline size_t roundUpToPowerOf(size_t v)
+{
+ return round(pow(static_cast<double>(exponent), ceil(log(static_cast<double>(v)) / log(static_cast<double>(exponent)))));
+}
+
+// From http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
+template<> inline size_t roundUpToPowerOf<2>(size_t v)
+{
+ v--;
+ v |= v >> 1;
+ v |= v >> 2;
+ v |= v >> 4;
+ v |= v >> 8;
+ v |= v >> 16;
+#if defined(__LP64__) && __LP64__
+ v |= v >> 32;
+#endif
+ v++;
+ return v;
+}
+
+} // namespace WTF
+
#endif // #ifndef WTF_MathExtras_h
