--- /dev/null
+/*
+ * Copyright (C) 2013, 2014 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "DFGAbstractValue.h"
+
+#if ENABLE(DFG_JIT)
+
+#include "DFGGraph.h"
+#include "JSCInlines.h"
+
+namespace JSC { namespace DFG {
+
+void AbstractValue::setMostSpecific(Graph& graph, JSValue value)
+{
+ 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, JSValue value)
+{
+ if (!!value && value.isCell()) {
+ m_currentKnownStructure.makeTop();
+ Structure* structure = value.asCell()->structure();
+ setFuturePossibleStructure(graph, structure);
+ m_arrayModes = asArrayModes(structure->indexingType());
+ clobberArrayModes();
+ } else {
+ m_currentKnownStructure.clear();
+ m_futurePossibleStructure.clear();
+ m_arrayModes = 0;
+ }
+
+ m_type = speculationFromValue(value);
+ m_value = value;
+
+ checkConsistency();
+}
+
+void AbstractValue::set(Graph& graph, Structure* structure)
+{
+ m_currentKnownStructure = structure;
+ setFuturePossibleStructure(graph, structure);
+ m_arrayModes = asArrayModes(structure->indexingType());
+ m_type = speculationFromStructure(structure);
+ m_value = JSValue();
+
+ checkConsistency();
+}
+
+void AbstractValue::fixTypeForRepresentation(NodeFlags representation)
+{
+ 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) {
+ startCrashing();
+ dataLog("Abstract value ", *this, " for double node has type outside SpecFullDouble.\n");
+ CRASH();
+ }
+ } else if (representation == NodeResultInt52) {
+ if (m_type & SpecInt52AsDouble) {
+ m_type &= ~SpecInt52AsDouble;
+ m_type |= SpecInt52;
+ }
+ if (m_type & ~SpecMachineInt) {
+ startCrashing();
+ dataLog("Abstract value ", *this, " for int52 node has type outside SpecMachineInt.\n");
+ CRASH();
+ }
+ } else {
+ if (m_type & SpecInt52) {
+ m_type &= ~SpecInt52;
+ m_type |= SpecInt52AsDouble;
+ }
+ if (m_type & ~SpecBytecodeTop) {
+ startCrashing();
+ dataLog("Abstract value ", *this, " for value node has type outside SpecBytecodeTop.\n");
+ CRASH();
+ }
+ }
+
+ checkConsistency();
+}
+
+void AbstractValue::fixTypeForRepresentation(Node* node)
+{
+ fixTypeForRepresentation(node->result());
+}
+
+FiltrationResult AbstractValue::filter(Graph& graph, const StructureSet& other)
+{
+ if (isClear())
+ return FiltrationOK;
+
+ // FIXME: This could be optimized for the common case of m_type not
+ // having structures, array modes, or a specific value.
+ // https://bugs.webkit.org/show_bug.cgi?id=109663
+
+ m_type &= other.speculationFromStructures();
+ m_arrayModes &= other.arrayModesFromStructures();
+ 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_currentKnownStructure.filter(m_type);
+
+ if (m_currentKnownStructure.hasSingleton())
+ setFuturePossibleStructure(graph, m_currentKnownStructure.singleton());
+
+ filterArrayModesByType();
+ filterValueByType();
+ return normalizeClarity();
+}
+
+FiltrationResult AbstractValue::filterArrayModes(ArrayModes arrayModes)
+{
+ ASSERT(arrayModes);
+
+ if (isClear())
+ return FiltrationOK;
+
+ m_type &= SpecCell;
+ m_arrayModes &= arrayModes;
+ return normalizeClarity();
+}
+
+FiltrationResult AbstractValue::filter(SpeculatedType type)
+{
+ if ((m_type & type) == m_type)
+ return FiltrationOK;
+
+ 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_currentKnownStructure.filter(m_type);
+ m_futurePossibleStructure.filter(m_type);
+ filterArrayModesByType();
+ filterValueByType();
+ return normalizeClarity();
+}
+
+FiltrationResult AbstractValue::filterByValue(JSValue value)
+{
+ FiltrationResult result = filter(speculationFromValue(value));
+ if (m_type)
+ m_value = value;
+ return result;
+}
+
+void AbstractValue::setFuturePossibleStructure(Graph& graph, Structure* structure)
+{
+ ASSERT(structure);
+ if (graph.watchpoints().isStillValid(structure->transitionWatchpointSet()))
+ m_futurePossibleStructure = structure;
+ else
+ m_futurePossibleStructure.makeTop();
+}
+
+void AbstractValue::filterValueByType()
+{
+ // We could go further, and ensure that if the futurePossibleStructure contravenes
+ // the value, then we could clear both of those things. But that's unlikely to help
+ // in any realistic scenario, so we don't do it. Simpler is better.
+
+ if (!!m_type) {
+ // The type is still non-empty. It may be that the new type renders
+ // the value empty because it contravenes the constant value we had.
+ if (m_value && !validateType(m_value))
+ clear();
+ return;
+ }
+
+ // The type has been rendered empty. That means that the value must now be invalid,
+ // as well.
+ ASSERT(!m_value || !validateType(m_value));
+ m_value = JSValue();
+}
+
+void AbstractValue::filterArrayModesByType()
+{
+ if (!(m_type & SpecCell))
+ m_arrayModes = 0;
+ else if (!(m_type & ~SpecArray))
+ m_arrayModes &= ALL_ARRAY_ARRAY_MODES;
+
+ // NOTE: If m_type doesn't have SpecArray set, that doesn't mean that the
+ // array modes have to be a subset of ALL_NON_ARRAY_ARRAY_MODES, since
+ // in the speculated type type-system, RegExpMatchesArry and ArrayPrototype
+ // are Otherobj (since they are not *exactly* JSArray) but in the ArrayModes
+ // type system they are arrays (since they expose the magical length
+ // property and are otherwise allocated using array allocation). Hence the
+ // following would be wrong:
+ //
+ // if (!(m_type & SpecArray))
+ // m_arrayModes &= ALL_NON_ARRAY_ARRAY_MODES;
+}
+
+bool AbstractValue::shouldBeClear() const
+{
+ if (m_type == SpecNone)
+ return true;
+
+ if (!(m_type & ~SpecCell)
+ && (!m_arrayModes
+ || m_currentKnownStructure.isClear()))
+ return true;
+
+ return false;
+}
+
+FiltrationResult AbstractValue::normalizeClarity()
+{
+ // It's useful to be able to quickly check if an abstract value is clear.
+ // This normalizes everything to make that easy.
+
+ FiltrationResult result;
+
+ if (shouldBeClear()) {
+ clear();
+ result = Contradiction;
+ } else
+ result = FiltrationOK;
+
+ checkConsistency();
+
+ return result;
+}
+
+#if !ASSERT_DISABLED
+void AbstractValue::checkConsistency() const
+{
+ if (!(m_type & SpecCell)) {
+ ASSERT(m_currentKnownStructure.isClear());
+ ASSERT(m_futurePossibleStructure.isClear());
+ ASSERT(!m_arrayModes);
+ }
+
+ if (isClear())
+ ASSERT(!m_value);
+
+ 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);
+ }
+
+ // Note that it's possible for a prediction like (Final, []). This really means that
+ // the value is bottom and that any code that uses the value is unreachable. But
+ // we don't want to get pedantic about this as it would only increase the computational
+ // complexity of the code.
+}
+#endif
+
+void AbstractValue::dump(PrintStream& out) const
+{
+ dumpInContext(out, 0);
+}
+
+void AbstractValue::dumpInContext(PrintStream& out, DumpContext* context) const
+{
+ out.print("(", SpeculationDump(m_type));
+ if (m_type & SpecCell) {
+ out.print(
+ ", ", ArrayModesDump(m_arrayModes), ", ",
+ inContext(m_currentKnownStructure, context), ", ",
+ inContext(m_futurePossibleStructure, context));
+ }
+ if (!!m_value)
+ out.print(", ", inContext(m_value, context));
+ out.print(")");
+}
+
+} } // namespace JSC::DFG
+
+#endif // ENABLE(DFG_JIT)
+
projects / apple / javascriptcore.git / blobdiff