Changeset 131982 in webkit for trunk/Source/JavaScriptCore/dfg/DFGArrayMode.cpp

Timestamp:

Oct 19, 2012, 11:53:04 PM (13 years ago)

Author:

[email protected]

Message:

DFG should have some facility for recognizing redundant CheckArrays and Arrayifies
​https://bugs.webkit.org/show_bug.cgi?id=99287

Reviewed by Mark Hahnenberg.

Adds reasoning about indexing type sets (i.e. ArrayModes) to AbstractValue, which
then enables us to fold away CheckArray's and Arrayify's that are redundant.

• bytecode/ArrayProfile.cpp:

(JSC::arrayModesToString):
(JSC):

• bytecode/ArrayProfile.h:

(JSC):
(JSC::mergeArrayModes):
(JSC::arrayModesAlreadyChecked):

• bytecode/StructureSet.h:

(JSC::StructureSet::arrayModesFromStructures):
(StructureSet):

• dfg/DFGAbstractState.cpp:

(JSC::DFG::AbstractState::execute):

• dfg/DFGAbstractValue.h:

(JSC::DFG::AbstractValue::AbstractValue):
(JSC::DFG::AbstractValue::clear):
(JSC::DFG::AbstractValue::isClear):
(JSC::DFG::AbstractValue::makeTop):
(JSC::DFG::AbstractValue::clobberStructures):
(AbstractValue):
(JSC::DFG::AbstractValue::setMostSpecific):
(JSC::DFG::AbstractValue::set):
(JSC::DFG::AbstractValue::operator==):
(JSC::DFG::AbstractValue::merge):
(JSC::DFG::AbstractValue::filter):
(JSC::DFG::AbstractValue::filterArrayModes):
(JSC::DFG::AbstractValue::validate):
(JSC::DFG::AbstractValue::checkConsistency):
(JSC::DFG::AbstractValue::dump):
(JSC::DFG::AbstractValue::clobberArrayModes):
(JSC::DFG::AbstractValue::clobberArrayModesSlow):
(JSC::DFG::AbstractValue::setFuturePossibleStructure):
(JSC::DFG::AbstractValue::filterFuturePossibleStructure):

• dfg/DFGArrayMode.cpp:

(JSC::DFG::modeAlreadyChecked):

• dfg/DFGArrayMode.h:

(JSC::DFG::arrayModesFor):
(DFG):

• dfg/DFGConstantFoldingPhase.cpp:

(JSC::DFG::ConstantFoldingPhase::foldConstants):

• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::arrayify):

File:

• trunk/Source/JavaScriptCore/dfg/DFGArrayMode.cpp (modified) (6 diffs)

trunk/Source/JavaScriptCore/dfg/DFGArrayMode.cpp

@@ -168 +168 @@
     case Array::PossiblyArrayWithContiguousToTail:
     case Array::PossiblyArrayWithContiguousOutOfBounds:
+    case Array::ToContiguous:
+        if (arrayModesAlreadyChecked(value.m_arrayModes, asArrayModes(NonArrayWithContiguous) | asArrayModes(ArrayWithContiguous)))
+            return true;
         return value.m_currentKnownStructure.hasSingleton()
             && hasContiguous(value.m_currentKnownStructure.singleton()->indexingType());
@@ -174 +177 @@
     case Array::ArrayWithContiguousToTail:
     case Array::ArrayWithContiguousOutOfBounds:
+        if (arrayModesAlreadyChecked(value.m_arrayModes, asArrayModes(ArrayWithContiguous)))
+            return true;
         return value.m_currentKnownStructure.hasSingleton()
             && hasContiguous(value.m_currentKnownStructure.singleton()->indexingType())
@@ -184 +189 @@
     case Array::PossiblyArrayWithArrayStorageToHole:
     case Array::PossiblyArrayWithArrayStorageOutOfBounds:
+    case Array::ToArrayStorage:
+    case Array::PossiblyArrayToArrayStorage:
+        if (arrayModesAlreadyChecked(value.m_arrayModes, asArrayModes(NonArrayWithArrayStorage) | asArrayModes(ArrayWithArrayStorage)))
+            return true;
         return value.m_currentKnownStructure.hasSingleton()
             && hasFastArrayStorage(value.m_currentKnownStructure.singleton()->indexingType());
@@ -189 +198 @@
     case Array::SlowPutArrayStorage:
     case Array::PossiblyArrayWithSlowPutArrayStorage:
+    case Array::ToSlowPutArrayStorage:
+        if (arrayModesAlreadyChecked(value.m_arrayModes, asArrayModes(NonArrayWithArrayStorage) | asArrayModes(ArrayWithArrayStorage) | asArrayModes(NonArrayWithSlowPutArrayStorage) | asArrayModes(ArrayWithSlowPutArrayStorage)))
+            return true;
         return value.m_currentKnownStructure.hasSingleton()
             && hasArrayStorage(value.m_currentKnownStructure.singleton()->indexingType());
@@ -195 +207 @@
     case Array::ArrayWithArrayStorageToHole:
     case Array::ArrayWithArrayStorageOutOfBounds:
+    case Array::ArrayToArrayStorage:
+        if (arrayModesAlreadyChecked(value.m_arrayModes, asArrayModes(ArrayWithArrayStorage)))
+            return true;
         return value.m_currentKnownStructure.hasSingleton()
             && hasFastArrayStorage(value.m_currentKnownStructure.singleton()->indexingType())
@@ -200 +215 @@
         
     case Array::ArrayWithSlowPutArrayStorage:
+        if (arrayModesAlreadyChecked(value.m_arrayModes, asArrayModes(ArrayWithArrayStorage) | asArrayModes(ArrayWithSlowPutArrayStorage)))
+            return true;
         return value.m_currentKnownStructure.hasSingleton()
             && hasArrayStorage(value.m_currentKnownStructure.singleton()->indexingType())
             && (value.m_currentKnownStructure.singleton()->indexingType() & IsArray);
-        
-    case ALL_EFFECTFUL_MODES:
-        return false;
         
     case Array::Arguments: