webkitgtk-2.4.11webkitgtk-2.4.11

1 files changed, 58 insertions, 320 deletions

diff --git a/Source/JavaScriptCore/dfg/DFGAbstractValue.cpp b/Source/JavaScriptCore/dfg/DFGAbstractValue.cpp
index b6fcf8993..bd1ba4844 100644
--- a/Source/JavaScriptCore/dfg/DFGAbstractValue.cpp
+++ b/Source/JavaScriptCore/dfg/DFGAbstractValue.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013-2015 Apple Inc. All rights reserved.
+ * Copyright (C) 2013 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -29,235 +29,64 @@
 #if ENABLE(DFG_JIT)
 
 #include "DFGGraph.h"
-#include "JSCInlines.h"
-#include "TrackedReferences.h"
+#include "Operations.h"
 
 namespace JSC { namespace DFG {
 
-void AbstractValue::observeTransitions(const TransitionVector& vector)
+void AbstractValue::setMostSpecific(Graph& graph, JSValue value)
 {
-    if (m_type & SpecCell) {
-        m_structure.observeTransitions(vector);
-        ArrayModes newModes = 0;
-        for (unsigned i = vector.size(); i--;) {
-            if (m_arrayModes & asArrayModes(vector[i].previous->indexingType()))
-                newModes |= asArrayModes(vector[i].next->indexingType());
-        }
-        m_arrayModes |= newModes;
+    if (!!value && value.isCell()) {
+        Structure* structure = value.asCell()->structure();
+        m_currentKnownStructure = structure;
+        setFuturePossibleStructure(graph, structure);
+        m_arrayModes = asArrayModes(structure->indexingType());
+    } else {
+        m_currentKnownStructure.clear();
+        m_futurePossibleStructure.clear();
+        m_arrayModes = 0;
     }
+        
+    m_type = speculationFromValue(value);
+    m_value = value;
+        
     checkConsistency();
 }
 
-void AbstractValue::set(Graph& graph, const FrozenValue& value, StructureClobberState clobberState)
+void AbstractValue::set(Graph& graph, JSValue value)
 {
-    if (!!value && value.value().isCell()) {
-        Structure* structure = value.structure();
-        if (graph.registerStructure(structure) == StructureRegisteredAndWatched) {
-            m_structure = structure;
-            if (clobberState == StructuresAreClobbered) {
-                m_arrayModes = ALL_ARRAY_MODES;
-                m_structure.clobber();
-            } else
-                m_arrayModes = asArrayModes(structure->indexingType());
-        } else {
-            m_structure.makeTop();
-            m_arrayModes = ALL_ARRAY_MODES;
-        }
+    if (!!value && value.isCell()) {
+        m_currentKnownStructure.makeTop();
+        Structure* structure = value.asCell()->structure();
+        setFuturePossibleStructure(graph, structure);
+        m_arrayModes = asArrayModes(structure->indexingType());
+        clobberArrayModes();
     } else {
-        m_structure.clear();
+        m_currentKnownStructure.clear();
+        m_futurePossibleStructure.clear();
         m_arrayModes = 0;
     }
-    
-    m_type = speculationFromValue(value.value());
-    m_value = value.value();
-    
+        
+    m_type = speculationFromValue(value);
+    if (m_type == SpecInt52AsDouble)
+        m_type = SpecInt52;
+    m_value = value;
+        
     checkConsistency();
-    assertIsRegistered(graph);
 }
 
 void AbstractValue::set(Graph& graph, Structure* structure)
 {
-    m_structure = structure;
+    m_currentKnownStructure = structure;
+    setFuturePossibleStructure(graph, structure);
     m_arrayModes = asArrayModes(structure->indexingType());
     m_type = speculationFromStructure(structure);
     m_value = JSValue();
     
     checkConsistency();
-    assertIsRegistered(graph);
-}
-
-void AbstractValue::set(Graph& graph, const StructureSet& set)
-{
-    m_structure = set;
-    m_arrayModes = set.arrayModesFromStructures();
-    m_type = set.speculationFromStructures();
-    m_value = JSValue();
-    
-    checkConsistency();
-    assertIsRegistered(graph);
-}
-
-void AbstractValue::setType(Graph& graph, SpeculatedType type)
-{
-    SpeculatedType cellType = type & SpecCell;
-    if (cellType) {
-        if (!(cellType & ~SpecString))
-            m_structure = graph.m_vm.stringStructure.get();
-        else if (isSymbolSpeculation(cellType))
-            m_structure = graph.m_vm.symbolStructure.get();
-        else
-            m_structure.makeTop();
-        m_arrayModes = ALL_ARRAY_MODES;
-    } else {
-        m_structure.clear();
-        m_arrayModes = 0;
-    }
-    m_type = type;
-    m_value = JSValue();
-    checkConsistency();
-}
-
-void AbstractValue::set(Graph& graph, const InferredType::Descriptor& descriptor)
-{
-    switch (descriptor.kind()) {
-    case InferredType::Bottom:
-        clear();
-        return;
-    case InferredType::Boolean:
-        setType(SpecBoolean);
-        return;
-    case InferredType::Other:
-        setType(SpecOther);
-        return;
-    case InferredType::Int32:
-        setType(SpecInt32);
-        return;
-    case InferredType::Number:
-        setType(SpecBytecodeNumber);
-        return;
-    case InferredType::String:
-        set(graph, graph.m_vm.stringStructure.get());
-        return;
-    case InferredType::Symbol:
-        set(graph, graph.m_vm.symbolStructure.get());
-        return;
-    case InferredType::ObjectWithStructure:
-        set(graph, descriptor.structure());
-        return;
-    case InferredType::ObjectWithStructureOrOther:
-        set(graph, descriptor.structure());
-        merge(SpecOther);
-        return;
-    case InferredType::Object:
-        setType(graph, SpecObject);
-        return;
-    case InferredType::ObjectOrOther:
-        setType(graph, SpecObject | SpecOther);
-        return;
-    case InferredType::Top:
-        makeHeapTop();
-        return;
-    }
-
-    RELEASE_ASSERT_NOT_REACHED();
-}
-
-void AbstractValue::set(
-    Graph& graph, const InferredType::Descriptor& descriptor, StructureClobberState clobberState)
-{
-    set(graph, descriptor);
-    if (clobberState == StructuresAreClobbered)
-        clobberStructures();
-}
-
-void AbstractValue::fixTypeForRepresentation(Graph& graph, NodeFlags representation, Node* node)
-{
-    if (representation == NodeResultDouble) {
-        if (m_value) {
-            ASSERT(m_value.isNumber());
-            if (m_value.isInt32())
-                m_value = jsDoubleNumber(m_value.asNumber());
-        }
-        if (m_type & SpecMachineInt) {
-            m_type &= ~SpecMachineInt;
-            m_type |= SpecInt52AsDouble;
-        }
-        if (m_type & ~SpecFullDouble)
-            DFG_CRASH(graph, node, toCString("Abstract value ", *this, " for double node has type outside SpecFullDouble.\n").data());
-    } else if (representation == NodeResultInt52) {
-        if (m_type & SpecInt52AsDouble) {
-            m_type &= ~SpecInt52AsDouble;
-            m_type |= SpecInt52;
-        }
-        if (m_type & ~SpecMachineInt)
-            DFG_CRASH(graph, node, toCString("Abstract value ", *this, " for int52 node has type outside SpecMachineInt.\n").data());
-    } else {
-        if (m_type & SpecInt52) {
-            m_type &= ~SpecInt52;
-            m_type |= SpecInt52AsDouble;
-        }
-        if (m_type & ~SpecBytecodeTop)
-            DFG_CRASH(graph, node, toCString("Abstract value ", *this, " for value node has type outside SpecBytecodeTop.\n").data());
-    }
-    
-    checkConsistency();
-}
-
-void AbstractValue::fixTypeForRepresentation(Graph& graph, Node* node)
-{
-    fixTypeForRepresentation(graph, node->result(), node);
-}
-
-bool AbstractValue::mergeOSREntryValue(Graph& graph, JSValue value)
-{
-    AbstractValue oldMe = *this;
-    
-    if (isClear()) {
-        FrozenValue* frozenValue = graph.freeze(value);
-        if (frozenValue->pointsToHeap()) {
-            m_structure = frozenValue->structure();
-            m_arrayModes = asArrayModes(frozenValue->structure()->indexingType());
-        } else {
-            m_structure.clear();
-            m_arrayModes = 0;
-        }
-        
-        m_type = speculationFromValue(value);
-        m_value = value;
-    } else {
-        mergeSpeculation(m_type, speculationFromValue(value));
-        if (!!value && value.isCell()) {
-            Structure* structure = value.asCell()->structure();
-            graph.registerStructure(structure);
-            mergeArrayModes(m_arrayModes, asArrayModes(structure->indexingType()));
-            m_structure.merge(StructureSet(structure));
-        }
-        if (m_value != value)
-            m_value = JSValue();
-    }
-    
-    checkConsistency();
-    assertIsRegistered(graph);
-    
-    return oldMe != *this;
 }
 
-bool AbstractValue::isType(Graph& graph, const InferredType::Descriptor& inferredType) const
+FiltrationResult AbstractValue::filter(Graph& graph, const StructureSet& other)
 {
-    AbstractValue typeValue;
-    typeValue.set(graph, inferredType);
-
-    AbstractValue mergedValue = *this;
-    mergedValue.merge(typeValue);
-
-    return mergedValue == typeValue;
-}
-
-FiltrationResult AbstractValue::filter(
-    Graph& graph, const StructureSet& other, SpeculatedType admittedTypes)
-{
-    ASSERT(!(admittedTypes & SpecCell));
-    
     if (isClear())
         return FiltrationOK;
     
@@ -265,31 +94,23 @@ FiltrationResult AbstractValue::filter(
     // having structures, array modes, or a specific value.
     // https://bugs.webkit.org/show_bug.cgi?id=109663
     
-    m_type &= other.speculationFromStructures() | admittedTypes;
+    m_type &= other.speculationFromStructures();
     m_arrayModes &= other.arrayModesFromStructures();
-    m_structure.filter(other);
+    m_currentKnownStructure.filter(other);
     
     // It's possible that prior to the above two statements we had (Foo, TOP), where
     // Foo is a SpeculatedType that is disjoint with the passed StructureSet. In that
     // case, we will now have (None, [someStructure]). In general, we need to make
     // sure that new information gleaned from the SpeculatedType needs to be fed back
     // into the information gleaned from the StructureSet.
-    m_structure.filter(m_type);
+    m_currentKnownStructure.filter(m_type);
     
+    if (m_currentKnownStructure.hasSingleton())
+        setFuturePossibleStructure(graph, m_currentKnownStructure.singleton());
+        
     filterArrayModesByType();
     filterValueByType();
-    return normalizeClarity(graph);
-}
-
-FiltrationResult AbstractValue::changeStructure(Graph& graph, const StructureSet& other)
-{
-    m_type &= other.speculationFromStructures();
-    m_arrayModes = other.arrayModesFromStructures();
-    m_structure = other;
-    
-    filterValueByType();
-    
-    return normalizeClarity(graph);
+    return normalizeClarity();
 }
 
 FiltrationResult AbstractValue::filterArrayModes(ArrayModes arrayModes)
@@ -309,84 +130,34 @@ FiltrationResult AbstractValue::filter(SpeculatedType type)
     if ((m_type & type) == m_type)
         return FiltrationOK;
     
-    // Fast path for the case that we don't even have a cell.
-    if (!(m_type & SpecCell)) {
-        m_type &= type;
-        FiltrationResult result;
-        if (m_type == SpecNone) {
-            clear();
-            result = Contradiction;
-        } else
-            result = FiltrationOK;
-        checkConsistency();
-        return result;
-    }
-    
     m_type &= type;
     
     // It's possible that prior to this filter() call we had, say, (Final, TOP), and
     // the passed type is Array. At this point we'll have (None, TOP). The best way
     // to ensure that the structure filtering does the right thing is to filter on
     // the new type (None) rather than the one passed (Array).
-    m_structure.filter(type);
+    m_currentKnownStructure.filter(m_type);
+    m_futurePossibleStructure.filter(m_type);
     filterArrayModesByType();
     filterValueByType();
     return normalizeClarity();
 }
 
-FiltrationResult AbstractValue::filterByValue(const FrozenValue& value)
+FiltrationResult AbstractValue::filterByValue(JSValue value)
 {
-    FiltrationResult result = filter(speculationFromValue(value.value()));
+    FiltrationResult result = filter(speculationFromValue(value));
     if (m_type)
-        m_value = value.value();
+        m_value = value;
     return result;
 }
 
-bool AbstractValue::contains(Structure* structure) const
+void AbstractValue::setFuturePossibleStructure(Graph& graph, Structure* structure)
 {
-    return couldBeType(speculationFromStructure(structure))
-        && (m_arrayModes & arrayModeFromStructure(structure))
-        && m_structure.contains(structure);
-}
-
-FiltrationResult AbstractValue::filter(const AbstractValue& other)
-{
-    m_type &= other.m_type;
-    m_structure.filter(other.m_structure);
-    m_arrayModes &= other.m_arrayModes;
-
-    m_structure.filter(m_type);
-    filterArrayModesByType();
-    filterValueByType();
-    
-    if (normalizeClarity() == Contradiction)
-        return Contradiction;
-    
-    if (m_value == other.m_value)
-        return FiltrationOK;
-    
-    // Neither of us are BOTTOM, so an empty value means TOP.
-    if (!m_value) {
-        // We previously didn't prove a value but now we have done so.
-        m_value = other.m_value; 
-        return FiltrationOK;
-    }
-    
-    if (!other.m_value) {
-        // We had proved a value but the other guy hadn't, so keep our proof.
-        return FiltrationOK;
-    }
-    
-    // We both proved there to be a specific value but they are different.
-    clear();
-    return Contradiction;
-}
-
-FiltrationResult AbstractValue::filter(Graph& graph, const InferredType::Descriptor& descriptor)
-{
-    AbstractValue filterValue;
-    filterValue.set(graph, descriptor);
-    return filter(filterValue);
+    ASSERT(structure);
+    if (graph.watchpoints().isStillValid(structure->transitionWatchpointSet()))
+        m_futurePossibleStructure = structure;
+    else
+        m_futurePossibleStructure.makeTop();
 }
 
 void AbstractValue::filterValueByType()
@@ -434,7 +205,8 @@ bool AbstractValue::shouldBeClear() const
         return true;
     
     if (!(m_type & ~SpecCell)
-        && (!m_arrayModes || m_structure.isClear()))
+        && (!m_arrayModes
+            || m_currentKnownStructure.isClear()))
         return true;
     
     return false;
@@ -458,18 +230,12 @@ FiltrationResult AbstractValue::normalizeClarity()
     return result;
 }
 
-FiltrationResult AbstractValue::normalizeClarity(Graph& graph)
-{
-    FiltrationResult result = normalizeClarity();
-    assertIsRegistered(graph);
-    return result;
-}
-
 #if !ASSERT_DISABLED
 void AbstractValue::checkConsistency() const
 {
     if (!(m_type & SpecCell)) {
-        ASSERT(m_structure.isClear());
+        ASSERT(m_currentKnownStructure.isClear());
+        ASSERT(m_futurePossibleStructure.isClear());
         ASSERT(!m_arrayModes);
     }
     
@@ -478,8 +244,6 @@ void AbstractValue::checkConsistency() const
     
     if (!!m_value) {
         SpeculatedType type = m_type;
-        // This relaxes the assertion below a bit, since we don't know the representation of the
-        // node.
         if (type & SpecInt52)
             type |= SpecInt52AsDouble;
         ASSERT(mergeSpeculations(type, speculationFromValue(m_value)) == type);
@@ -490,29 +254,8 @@ void AbstractValue::checkConsistency() const
     // we don't want to get pedantic about this as it would only increase the computational
     // complexity of the code.
 }
-
-void AbstractValue::assertIsRegistered(Graph& graph) const
-{
-    m_structure.assertIsRegistered(graph);
-}
 #endif
 
-ResultType AbstractValue::resultType() const
-{
-    ASSERT(isType(SpecBytecodeTop));
-    if (isType(SpecBoolean))
-        return ResultType::booleanType();
-    if (isType(SpecInt32))
-        return ResultType::numberTypeIsInt32();
-    if (isType(SpecBytecodeNumber))
-        return ResultType::numberType();
-    if (isType(SpecString))
-        return ResultType::stringType();
-    if (isType(SpecString | SpecBytecodeNumber))
-        return ResultType::stringOrNumberType();
-    return ResultType::unknownType();
-}
-
 void AbstractValue::dump(PrintStream& out) const
 {
     dumpInContext(out, 0);
@@ -524,19 +267,14 @@ void AbstractValue::dumpInContext(PrintStream& out, DumpContext* context) const
     if (m_type & SpecCell) {
         out.print(
             ", ", ArrayModesDump(m_arrayModes), ", ",
-            inContext(m_structure, context));
+            inContext(m_currentKnownStructure, context), ", ",
+            inContext(m_futurePossibleStructure, context));
     }
     if (!!m_value)
         out.print(", ", inContext(m_value, context));
     out.print(")");
 }
 
-void AbstractValue::validateReferences(const TrackedReferences& trackedReferences)
-{
-    trackedReferences.check(m_value);
-    m_structure.validateReferences(trackedReferences);
-}
-
 } } // namespace JSC::DFG
 
 #endif // ENABLE(DFG_JIT)