| /* |
| * Copyright (C) 2012-2015 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 "DFGConstantFoldingPhase.h" |
| |
| #if ENABLE(DFG_JIT) |
| |
| #include "DFGAbstractInterpreterInlines.h" |
| #include "DFGArgumentsUtilities.h" |
| #include "DFGBasicBlockInlines.h" |
| #include "DFGGraph.h" |
| #include "DFGInPlaceAbstractState.h" |
| #include "DFGInferredTypeCheck.h" |
| #include "DFGInsertionSet.h" |
| #include "DFGPhase.h" |
| #include "GetByIdStatus.h" |
| #include "JSCInlines.h" |
| #include "PutByIdStatus.h" |
| |
| namespace JSC { namespace DFG { |
| |
| class ConstantFoldingPhase : public Phase { |
| public: |
| ConstantFoldingPhase(Graph& graph) |
| : Phase(graph, "constant folding") |
| , m_state(graph) |
| , m_interpreter(graph, m_state) |
| , m_insertionSet(graph) |
| { |
| } |
| |
| bool run() |
| { |
| bool changed = false; |
| |
| for (BasicBlock* block : m_graph.blocksInNaturalOrder()) { |
| if (block->cfaFoundConstants) |
| changed |= foldConstants(block); |
| } |
| |
| if (changed && m_graph.m_form == SSA) { |
| // It's now possible that we have Upsilons pointed at JSConstants. Fix that. |
| for (BasicBlock* block : m_graph.blocksInNaturalOrder()) |
| fixUpsilons(block); |
| } |
| |
| if (m_graph.m_form == SSA) { |
| // It's now possible to simplify basic blocks by placing an Unreachable terminator right |
| // after anything that invalidates AI. |
| bool didClipBlock = false; |
| Vector<Node*> nodesToDelete; |
| for (BasicBlock* block : m_graph.blocksInNaturalOrder()) { |
| m_state.beginBasicBlock(block); |
| for (unsigned nodeIndex = 0; nodeIndex < block->size(); ++nodeIndex) { |
| if (block->at(nodeIndex)->isTerminal()) { |
| // It's possible that we have something after the terminal. It could be a |
| // no-op Check node, for example. We don't want the logic below to turn that |
| // node into Unreachable, since then we'd have two terminators. |
| break; |
| } |
| if (!m_state.isValid()) { |
| NodeOrigin origin = block->at(nodeIndex)->origin; |
| for (unsigned killIndex = nodeIndex; killIndex < block->size(); ++killIndex) |
| nodesToDelete.append(block->at(killIndex)); |
| block->resize(nodeIndex); |
| block->appendNode(m_graph, SpecNone, Unreachable, origin); |
| didClipBlock = true; |
| break; |
| } |
| m_interpreter.execute(nodeIndex); |
| } |
| m_state.reset(); |
| } |
| |
| if (didClipBlock) { |
| changed = true; |
| |
| m_graph.invalidateNodeLiveness(); |
| |
| for (Node* node : nodesToDelete) |
| m_graph.deleteNode(node); |
| |
| m_graph.invalidateCFG(); |
| m_graph.resetReachability(); |
| m_graph.killUnreachableBlocks(); |
| } |
| } |
| |
| return changed; |
| } |
| |
| private: |
| bool foldConstants(BasicBlock* block) |
| { |
| bool changed = false; |
| m_state.beginBasicBlock(block); |
| for (unsigned indexInBlock = 0; indexInBlock < block->size(); ++indexInBlock) { |
| if (!m_state.isValid()) |
| break; |
| |
| Node* node = block->at(indexInBlock); |
| |
| bool alreadyHandled = false; |
| bool eliminated = false; |
| |
| switch (node->op()) { |
| case BooleanToNumber: { |
| if (node->child1().useKind() == UntypedUse |
| && !m_interpreter.needsTypeCheck(node->child1(), SpecBoolean)) |
| node->child1().setUseKind(BooleanUse); |
| break; |
| } |
| |
| case CompareEq: { |
| // FIXME: We should add back the broken folding phase here for comparisions where we prove at least one side has type SpecOther. |
| // See: https://bugs.webkit.org/show_bug.cgi?id=174844 |
| break; |
| } |
| |
| case CompareStrictEq: { |
| if (node->isBinaryUseKind(UntypedUse)) { |
| JSValue child1Constant = m_state.forNode(node->child1().node()).value(); |
| JSValue child2Constant = m_state.forNode(node->child2().node()).value(); |
| |
| // FIXME: Revisit this condition when introducing BigInt to JSC. |
| auto isNonStringCellConstant = [] (JSValue value) { |
| return value && value.isCell() && !value.isString(); |
| }; |
| |
| if (isNonStringCellConstant(child1Constant)) { |
| node->convertToCompareEqPtr(m_graph.freezeStrong(child1Constant.asCell()), node->child2()); |
| changed = true; |
| } else if (isNonStringCellConstant(child2Constant)) { |
| node->convertToCompareEqPtr(m_graph.freezeStrong(child2Constant.asCell()), node->child1()); |
| changed = true; |
| } |
| } |
| break; |
| } |
| |
| case CheckStructureOrEmpty: { |
| const AbstractValue& value = m_state.forNode(node->child1()); |
| if (value.m_type & SpecEmpty) |
| break; |
| node->convertCheckStructureOrEmptyToCheckStructure(); |
| changed = true; |
| FALLTHROUGH; |
| } |
| case CheckStructure: |
| case ArrayifyToStructure: { |
| AbstractValue& value = m_state.forNode(node->child1()); |
| RegisteredStructureSet set; |
| if (node->op() == ArrayifyToStructure) |
| set = node->structure(); |
| else { |
| set = node->structureSet(); |
| if ((SpecCellCheck & SpecEmpty) && node->child1().useKind() == CellUse && m_state.forNode(node->child1()).m_type & SpecEmpty) { |
| m_insertionSet.insertNode( |
| indexInBlock, SpecNone, AssertNotEmpty, node->origin, Edge(node->child1().node(), UntypedUse)); |
| } |
| } |
| if (value.m_structure.isSubsetOf(set)) { |
| m_interpreter.execute(indexInBlock); // Catch the fact that we may filter on cell. |
| node->remove(m_graph); |
| eliminated = true; |
| break; |
| } |
| break; |
| } |
| |
| case CheckSubClass: { |
| JSValue constant = m_state.forNode(node->child1()).value(); |
| if (constant) { |
| if (constant.isCell() && constant.asCell()->inherits(m_graph.m_vm, node->classInfo())) { |
| m_interpreter.execute(indexInBlock); |
| node->remove(m_graph); |
| eliminated = true; |
| break; |
| } |
| } |
| |
| AbstractValue& value = m_state.forNode(node->child1()); |
| |
| if (value.m_structure.isSubClassOf(node->classInfo())) { |
| m_interpreter.execute(indexInBlock); |
| node->remove(m_graph); |
| eliminated = true; |
| break; |
| } |
| break; |
| } |
| |
| case GetIndexedPropertyStorage: { |
| JSArrayBufferView* view = m_graph.tryGetFoldableView( |
| m_state.forNode(node->child1()).m_value, node->arrayMode()); |
| if (!view) |
| break; |
| |
| if (view->mode() == FastTypedArray) { |
| // FIXME: It would be awesome to be able to fold the property storage for |
| // these GC-allocated typed arrays. For now it doesn't matter because the |
| // most common use-cases for constant typed arrays involve large arrays with |
| // aliased buffer views. |
| // https://bugs.webkit.org/show_bug.cgi?id=125425 |
| break; |
| } |
| |
| m_interpreter.execute(indexInBlock); |
| eliminated = true; |
| |
| m_insertionSet.insertCheck(indexInBlock, node->origin, node->children); |
| node->convertToConstantStoragePointer(view->vector()); |
| break; |
| } |
| |
| case CheckStructureImmediate: { |
| AbstractValue& value = m_state.forNode(node->child1()); |
| const RegisteredStructureSet& set = node->structureSet(); |
| |
| if (value.value()) { |
| if (Structure* structure = jsDynamicCast<Structure*>(m_graph.m_vm, value.value())) { |
| if (set.contains(m_graph.registerStructure(structure))) { |
| m_interpreter.execute(indexInBlock); |
| node->remove(m_graph); |
| eliminated = true; |
| break; |
| } |
| } |
| } |
| |
| if (PhiChildren* phiChildren = m_interpreter.phiChildren()) { |
| bool allGood = true; |
| phiChildren->forAllTransitiveIncomingValues( |
| node, |
| [&] (Node* incoming) { |
| if (Structure* structure = incoming->dynamicCastConstant<Structure*>(m_graph.m_vm)) { |
| if (set.contains(m_graph.registerStructure(structure))) |
| return; |
| } |
| allGood = false; |
| }); |
| if (allGood) { |
| m_interpreter.execute(indexInBlock); |
| node->remove(m_graph); |
| eliminated = true; |
| break; |
| } |
| } |
| break; |
| } |
| |
| case CheckArray: |
| case Arrayify: { |
| if (!node->arrayMode().alreadyChecked(m_graph, node, m_state.forNode(node->child1()))) |
| break; |
| node->remove(m_graph); |
| eliminated = true; |
| break; |
| } |
| |
| case PutStructure: { |
| if (m_state.forNode(node->child1()).m_structure.onlyStructure() != node->transition()->next) |
| break; |
| |
| node->remove(m_graph); |
| eliminated = true; |
| break; |
| } |
| |
| case CheckCell: { |
| if (m_state.forNode(node->child1()).value() != node->cellOperand()->value()) |
| break; |
| node->remove(m_graph); |
| eliminated = true; |
| break; |
| } |
| |
| case AssertNotEmpty: |
| case CheckNotEmpty: { |
| if (m_state.forNode(node->child1()).m_type & SpecEmpty) |
| break; |
| node->remove(m_graph); |
| eliminated = true; |
| break; |
| } |
| |
| case CheckStringIdent: { |
| UniquedStringImpl* uid = node->uidOperand(); |
| const UniquedStringImpl* constantUid = nullptr; |
| |
| JSValue childConstant = m_state.forNode(node->child1()).value(); |
| if (childConstant) { |
| if (childConstant.isString()) { |
| if (const auto* impl = asString(childConstant)->tryGetValueImpl()) { |
| // Edge filtering requires that a value here should be StringIdent. |
| // However, a constant value propagated in DFG is not filtered. |
| // So here, we check the propagated value is actually an atomic string. |
| // And if it's not, we just ignore. |
| if (impl->isAtomic()) |
| constantUid = static_cast<const UniquedStringImpl*>(impl); |
| } |
| } |
| } |
| |
| if (constantUid == uid) { |
| node->remove(m_graph); |
| eliminated = true; |
| } |
| break; |
| } |
| |
| case CheckInBounds: { |
| JSValue left = m_state.forNode(node->child1()).value(); |
| JSValue right = m_state.forNode(node->child2()).value(); |
| if (left && right && left.isInt32() && right.isInt32() |
| && static_cast<uint32_t>(left.asInt32()) < static_cast<uint32_t>(right.asInt32())) { |
| node->remove(m_graph); |
| eliminated = true; |
| break; |
| } |
| |
| break; |
| } |
| |
| case GetMyArgumentByVal: |
| case GetMyArgumentByValOutOfBounds: { |
| JSValue indexValue = m_state.forNode(node->child2()).value(); |
| if (!indexValue || !indexValue.isUInt32()) |
| break; |
| |
| Checked<unsigned, RecordOverflow> checkedIndex = indexValue.asUInt32(); |
| checkedIndex += node->numberOfArgumentsToSkip(); |
| if (checkedIndex.hasOverflowed()) |
| break; |
| |
| unsigned index = checkedIndex.unsafeGet(); |
| Node* arguments = node->child1().node(); |
| InlineCallFrame* inlineCallFrame = arguments->origin.semantic.inlineCallFrame; |
| |
| // Don't try to do anything if the index is known to be outside our static bounds. Note |
| // that our static bounds are usually strictly larger than the dynamic bounds. The |
| // exception is something like this, assuming foo() is not inlined: |
| // |
| // function foo() { return arguments[5]; } |
| // |
| // Here the static bound on number of arguments is 0, and we're accessing index 5. We |
| // will not strength-reduce this to GetStack because GetStack is otherwise assumed by the |
| // compiler to access those variables that are statically accounted for; for example if |
| // we emitted a GetStack on arg6 we would have out-of-bounds access crashes anywhere that |
| // uses an Operands<> map. There is not much cost to continuing to use a |
| // GetMyArgumentByVal in such statically-out-of-bounds accesses; we just lose CFA unless |
| // GCSE removes the access entirely. |
| if (inlineCallFrame) { |
| if (index >= inlineCallFrame->argumentCountIncludingThis - 1) |
| break; |
| } else { |
| if (index >= m_state.variables().numberOfArguments() - 1) |
| break; |
| } |
| |
| m_interpreter.execute(indexInBlock); // Push CFA over this node after we get the state before. |
| |
| StackAccessData* data; |
| if (inlineCallFrame) { |
| data = m_graph.m_stackAccessData.add( |
| VirtualRegister( |
| inlineCallFrame->stackOffset + |
| CallFrame::argumentOffset(index)), |
| FlushedJSValue); |
| } else { |
| data = m_graph.m_stackAccessData.add( |
| virtualRegisterForArgument(index + 1), FlushedJSValue); |
| } |
| |
| if (inlineCallFrame && !inlineCallFrame->isVarargs() && index < inlineCallFrame->argumentCountIncludingThis - 1) { |
| node->convertToGetStack(data); |
| eliminated = true; |
| break; |
| } |
| |
| if (node->op() == GetMyArgumentByValOutOfBounds) |
| break; |
| |
| Node* length = emitCodeToGetArgumentsArrayLength( |
| m_insertionSet, arguments, indexInBlock, node->origin); |
| m_insertionSet.insertNode( |
| indexInBlock, SpecNone, CheckInBounds, node->origin, |
| node->child2(), Edge(length, Int32Use)); |
| node->convertToGetStack(data); |
| eliminated = true; |
| break; |
| } |
| |
| case MultiGetByOffset: { |
| Edge baseEdge = node->child1(); |
| Node* base = baseEdge.node(); |
| MultiGetByOffsetData& data = node->multiGetByOffsetData(); |
| |
| // First prune the variants, then check if the MultiGetByOffset can be |
| // strength-reduced to a GetByOffset. |
| |
| AbstractValue baseValue = m_state.forNode(base); |
| |
| m_interpreter.execute(indexInBlock); // Push CFA over this node after we get the state before. |
| alreadyHandled = true; // Don't allow the default constant folder to do things to this. |
| |
| for (unsigned i = 0; i < data.cases.size(); ++i) { |
| MultiGetByOffsetCase& getCase = data.cases[i]; |
| getCase.set().filter(baseValue); |
| if (getCase.set().isEmpty()) { |
| data.cases[i--] = data.cases.last(); |
| data.cases.removeLast(); |
| changed = true; |
| } |
| } |
| |
| if (data.cases.size() != 1) |
| break; |
| |
| emitGetByOffset(indexInBlock, node, baseValue, data.cases[0], data.identifierNumber); |
| changed = true; |
| break; |
| } |
| |
| case MultiPutByOffset: { |
| Edge baseEdge = node->child1(); |
| Node* base = baseEdge.node(); |
| MultiPutByOffsetData& data = node->multiPutByOffsetData(); |
| |
| AbstractValue baseValue = m_state.forNode(base); |
| |
| m_interpreter.execute(indexInBlock); // Push CFA over this node after we get the state before. |
| alreadyHandled = true; // Don't allow the default constant folder to do things to this. |
| |
| |
| for (unsigned i = 0; i < data.variants.size(); ++i) { |
| PutByIdVariant& variant = data.variants[i]; |
| variant.oldStructure().genericFilter([&] (Structure* structure) -> bool { |
| return baseValue.contains(m_graph.registerStructure(structure)); |
| }); |
| |
| if (variant.oldStructure().isEmpty()) { |
| data.variants[i--] = data.variants.last(); |
| data.variants.removeLast(); |
| changed = true; |
| continue; |
| } |
| |
| if (variant.kind() == PutByIdVariant::Transition |
| && variant.oldStructure().onlyStructure() == variant.newStructure()) { |
| variant = PutByIdVariant::replace( |
| variant.oldStructure(), |
| variant.offset(), |
| variant.requiredType()); |
| changed = true; |
| } |
| } |
| |
| if (data.variants.size() != 1) |
| break; |
| |
| emitPutByOffset( |
| indexInBlock, node, baseValue, data.variants[0], data.identifierNumber); |
| changed = true; |
| break; |
| } |
| |
| case GetByIdDirect: |
| case GetByIdDirectFlush: |
| case GetById: |
| case GetByIdFlush: { |
| Edge childEdge = node->child1(); |
| Node* child = childEdge.node(); |
| unsigned identifierNumber = node->identifierNumber(); |
| |
| AbstractValue baseValue = m_state.forNode(child); |
| |
| m_interpreter.execute(indexInBlock); // Push CFA over this node after we get the state before. |
| alreadyHandled = true; // Don't allow the default constant folder to do things to this. |
| |
| if (!baseValue.m_structure.isFinite() |
| || (node->child1().useKind() == UntypedUse || (baseValue.m_type & ~SpecCell))) |
| break; |
| |
| GetByIdStatus status = GetByIdStatus::computeFor( |
| baseValue.m_structure.toStructureSet(), m_graph.identifiers()[identifierNumber]); |
| if (!status.isSimple()) |
| break; |
| |
| for (unsigned i = status.numVariants(); i--;) { |
| if (!status[i].conditionSet().isEmpty()) { |
| // FIXME: We could handle prototype cases. |
| // https://bugs.webkit.org/show_bug.cgi?id=110386 |
| break; |
| } |
| } |
| |
| if (status.numVariants() == 1) { |
| emitGetByOffset(indexInBlock, node, baseValue, status[0], identifierNumber); |
| changed = true; |
| break; |
| } |
| |
| if (!isFTL(m_graph.m_plan.mode)) |
| break; |
| |
| MultiGetByOffsetData* data = m_graph.m_multiGetByOffsetData.add(); |
| for (const GetByIdVariant& variant : status.variants()) { |
| data->cases.append( |
| MultiGetByOffsetCase( |
| *m_graph.addStructureSet(variant.structureSet()), |
| GetByOffsetMethod::load(variant.offset()))); |
| } |
| data->identifierNumber = identifierNumber; |
| node->convertToMultiGetByOffset(data); |
| changed = true; |
| break; |
| } |
| |
| case PutById: |
| case PutByIdDirect: |
| case PutByIdFlush: { |
| NodeOrigin origin = node->origin; |
| Edge childEdge = node->child1(); |
| Node* child = childEdge.node(); |
| unsigned identifierNumber = node->identifierNumber(); |
| |
| ASSERT(childEdge.useKind() == CellUse); |
| |
| AbstractValue baseValue = m_state.forNode(child); |
| AbstractValue valueValue = m_state.forNode(node->child2()); |
| |
| m_interpreter.execute(indexInBlock); // Push CFA over this node after we get the state before. |
| alreadyHandled = true; // Don't allow the default constant folder to do things to this. |
| |
| if (!baseValue.m_structure.isFinite()) |
| break; |
| |
| PutByIdStatus status = PutByIdStatus::computeFor( |
| m_graph.globalObjectFor(origin.semantic), |
| baseValue.m_structure.toStructureSet(), |
| m_graph.identifiers()[identifierNumber], |
| node->op() == PutByIdDirect); |
| |
| if (!status.isSimple()) |
| break; |
| |
| ASSERT(status.numVariants()); |
| |
| if (status.numVariants() > 1 && !isFTL(m_graph.m_plan.mode)) |
| break; |
| |
| changed = true; |
| |
| bool allGood = true; |
| for (const PutByIdVariant& variant : status.variants()) { |
| if (!allGood) |
| break; |
| for (const ObjectPropertyCondition& condition : variant.conditionSet()) { |
| if (m_graph.watchCondition(condition)) |
| continue; |
| |
| Structure* structure = condition.object()->structure(); |
| if (!condition.structureEnsuresValidity(structure)) { |
| allGood = false; |
| break; |
| } |
| |
| m_insertionSet.insertNode( |
| indexInBlock, SpecNone, CheckStructure, node->origin, |
| OpInfo(m_graph.addStructureSet(structure)), |
| m_insertionSet.insertConstantForUse( |
| indexInBlock, node->origin, condition.object(), KnownCellUse)); |
| } |
| } |
| |
| if (!allGood) |
| break; |
| |
| if (status.numVariants() == 1) { |
| emitPutByOffset(indexInBlock, node, baseValue, status[0], identifierNumber); |
| break; |
| } |
| |
| ASSERT(isFTL(m_graph.m_plan.mode)); |
| |
| MultiPutByOffsetData* data = m_graph.m_multiPutByOffsetData.add(); |
| data->variants = status.variants(); |
| data->identifierNumber = identifierNumber; |
| node->convertToMultiPutByOffset(data); |
| break; |
| } |
| |
| case ToPrimitive: { |
| if (m_state.forNode(node->child1()).m_type & ~(SpecFullNumber | SpecBoolean | SpecString | SpecSymbol | SpecBigInt)) |
| break; |
| |
| node->convertToIdentity(); |
| changed = true; |
| break; |
| } |
| |
| case ToThis: { |
| ToThisResult result = isToThisAnIdentity(m_graph.m_vm, m_graph.executableFor(node->origin.semantic)->isStrictMode(), m_state.forNode(node->child1())); |
| if (result == ToThisResult::Identity) { |
| node->convertToIdentity(); |
| changed = true; |
| break; |
| } |
| if (result == ToThisResult::GlobalThis) { |
| node->convertToGetGlobalThis(); |
| changed = true; |
| break; |
| } |
| break; |
| } |
| |
| case CreateThis: { |
| if (JSValue base = m_state.forNode(node->child1()).m_value) { |
| if (auto* function = jsDynamicCast<JSFunction*>(m_graph.m_vm, base)) { |
| if (FunctionRareData* rareData = function->rareData()) { |
| if (Structure* structure = rareData->objectAllocationStructure()) { |
| // FIXME: we should be able to allocate a poly proto object here: |
| // https://bugs.webkit.org/show_bug.cgi?id=177517 |
| if (structure->hasMonoProto()) { |
| m_graph.freeze(rareData); |
| m_graph.watchpoints().addLazily(rareData->allocationProfileWatchpointSet()); |
| node->convertToNewObject(m_graph.registerStructure(structure)); |
| changed = true; |
| break; |
| } |
| } |
| } |
| } |
| } |
| break; |
| } |
| |
| case ToNumber: { |
| if (m_state.forNode(node->child1()).m_type & ~SpecBytecodeNumber) |
| break; |
| |
| node->convertToIdentity(); |
| changed = true; |
| break; |
| } |
| |
| case NormalizeMapKey: { |
| SpeculatedType typeMaybeNormalized = (SpecFullNumber & ~SpecInt32Only); |
| if (m_state.forNode(node->child1()).m_type & typeMaybeNormalized) |
| break; |
| |
| node->convertToIdentity(); |
| changed = true; |
| break; |
| } |
| |
| case ParseInt: { |
| AbstractValue& value = m_state.forNode(node->child1()); |
| if (!value.m_type || (value.m_type & ~SpecInt32Only)) |
| break; |
| |
| JSValue radix; |
| if (!node->child2()) |
| radix = jsNumber(0); |
| else |
| radix = m_state.forNode(node->child2()).m_value; |
| |
| if (!radix.isNumber()) |
| break; |
| |
| if (radix.asNumber() == 0 || radix.asNumber() == 10) { |
| node->child2() = Edge(); |
| node->convertToIdentity(); |
| changed = true; |
| } |
| |
| break; |
| } |
| |
| case NumberToStringWithRadix: { |
| JSValue radixValue = m_state.forNode(node->child2()).m_value; |
| if (radixValue && radixValue.isInt32()) { |
| int32_t radix = radixValue.asInt32(); |
| if (2 <= radix && radix <= 36) { |
| if (radix == 10) { |
| node->setOpAndDefaultFlags(ToString); |
| node->clearFlags(NodeMustGenerate); |
| node->child2() = Edge(); |
| } else |
| node->convertToNumberToStringWithValidRadixConstant(radix); |
| changed = true; |
| break; |
| } |
| } |
| break; |
| } |
| |
| case Check: { |
| alreadyHandled = true; |
| m_interpreter.execute(indexInBlock); |
| for (unsigned i = 0; i < AdjacencyList::Size; ++i) { |
| Edge edge = node->children.child(i); |
| if (!edge) |
| break; |
| if (edge.isProved() || edge.willNotHaveCheck()) { |
| node->children.removeEdge(i--); |
| changed = true; |
| } |
| } |
| break; |
| } |
| |
| case CheckVarargs: { |
| alreadyHandled = true; |
| m_interpreter.execute(indexInBlock); |
| unsigned targetIndex = 0; |
| for (unsigned i = 0; i < node->numChildren(); ++i) { |
| Edge& edge = m_graph.varArgChild(node, i); |
| if (!edge) |
| continue; |
| if (edge.isProved() || edge.willNotHaveCheck()) { |
| edge = Edge(); |
| changed = true; |
| continue; |
| } |
| Edge& dst = m_graph.varArgChild(node, targetIndex++); |
| std::swap(dst, edge); |
| } |
| node->children.setNumChildren(targetIndex); |
| break; |
| } |
| |
| case MakeRope: { |
| for (unsigned i = 0; i < AdjacencyList::Size; ++i) { |
| Edge& edge = node->children.child(i); |
| if (!edge) |
| break; |
| JSValue childConstant = m_state.forNode(edge).value(); |
| if (!childConstant) |
| continue; |
| if (!childConstant.isString()) |
| continue; |
| if (asString(childConstant)->length()) |
| continue; |
| |
| // Don't allow the MakeRope to have zero children. |
| if (!i && !node->child2()) |
| break; |
| |
| node->children.removeEdge(i--); |
| changed = true; |
| } |
| |
| if (!node->child2()) { |
| ASSERT(!node->child3()); |
| node->convertToIdentity(); |
| changed = true; |
| } |
| break; |
| } |
| |
| case PhantomNewObject: |
| case PhantomNewFunction: |
| case PhantomNewGeneratorFunction: |
| case PhantomNewAsyncGeneratorFunction: |
| case PhantomNewAsyncFunction: |
| case PhantomCreateActivation: |
| case PhantomDirectArguments: |
| case PhantomClonedArguments: |
| case PhantomCreateRest: |
| case PhantomSpread: |
| case PhantomNewArrayWithSpread: |
| case PhantomNewArrayBuffer: |
| case PhantomNewRegexp: |
| case BottomValue: |
| alreadyHandled = true; |
| break; |
| |
| default: |
| break; |
| } |
| |
| if (eliminated) { |
| changed = true; |
| continue; |
| } |
| |
| if (alreadyHandled) |
| continue; |
| |
| m_interpreter.execute(indexInBlock); |
| if (!m_state.isValid()) { |
| // If we invalidated then we shouldn't attempt to constant-fold. Here's an |
| // example: |
| // |
| // c: JSConstant(4.2) |
| // x: ValueToInt32(Check:Int32:@const) |
| // |
| // It would be correct for an analysis to assume that execution cannot |
| // proceed past @x. Therefore, constant-folding @x could be rather bad. But, |
| // the CFA may report that it found a constant even though it also reported |
| // that everything has been invalidated. This will only happen in a couple of |
| // the constant folding cases; most of them are also separately defensive |
| // about such things. |
| break; |
| } |
| if (!node->shouldGenerate() || m_state.didClobber() || node->hasConstant()) |
| continue; |
| |
| // Interesting fact: this freezing that we do right here may turn an fragile value into |
| // a weak value. See DFGValueStrength.h. |
| FrozenValue* value = m_graph.freeze(m_state.forNode(node).value()); |
| if (!*value) |
| continue; |
| |
| if (node->op() == GetLocal) { |
| // Need to preserve bytecode liveness in ThreadedCPS form. This wouldn't be necessary |
| // if it wasn't for https://bugs.webkit.org/show_bug.cgi?id=144086. |
| m_insertionSet.insertNode( |
| indexInBlock, SpecNone, PhantomLocal, node->origin, |
| OpInfo(node->variableAccessData())); |
| m_graph.dethread(); |
| } else |
| m_insertionSet.insertCheck(m_graph, indexInBlock, node); |
| m_graph.convertToConstant(node, value); |
| |
| changed = true; |
| } |
| m_state.reset(); |
| m_insertionSet.execute(block); |
| |
| return changed; |
| } |
| |
| void emitGetByOffset(unsigned indexInBlock, Node* node, const AbstractValue& baseValue, const MultiGetByOffsetCase& getCase, unsigned identifierNumber) |
| { |
| // When we get to here we have already emitted all of the requisite checks for everything. |
| // So, we just need to emit what the method object tells us to emit. |
| |
| addBaseCheck(indexInBlock, node, baseValue, getCase.set()); |
| |
| GetByOffsetMethod method = getCase.method(); |
| |
| switch (method.kind()) { |
| case GetByOffsetMethod::Invalid: |
| RELEASE_ASSERT_NOT_REACHED(); |
| return; |
| |
| case GetByOffsetMethod::Constant: |
| m_graph.convertToConstant(node, method.constant()); |
| return; |
| |
| case GetByOffsetMethod::Load: |
| emitGetByOffset(indexInBlock, node, node->child1(), identifierNumber, method.offset()); |
| return; |
| |
| case GetByOffsetMethod::LoadFromPrototype: { |
| Node* child = m_insertionSet.insertConstant( |
| indexInBlock, node->origin, method.prototype()); |
| emitGetByOffset( |
| indexInBlock, node, Edge(child, KnownCellUse), identifierNumber, method.offset()); |
| return; |
| } } |
| |
| RELEASE_ASSERT_NOT_REACHED(); |
| } |
| |
| void emitGetByOffset(unsigned indexInBlock, Node* node, const AbstractValue& baseValue, const GetByIdVariant& variant, unsigned identifierNumber) |
| { |
| Edge childEdge = node->child1(); |
| |
| addBaseCheck(indexInBlock, node, baseValue, variant.structureSet()); |
| |
| // We aren't set up to handle prototype stuff. |
| DFG_ASSERT(m_graph, node, variant.conditionSet().isEmpty()); |
| |
| if (JSValue value = m_graph.tryGetConstantProperty(baseValue.m_value, *m_graph.addStructureSet(variant.structureSet()), variant.offset())) { |
| m_graph.convertToConstant(node, m_graph.freeze(value)); |
| return; |
| } |
| |
| emitGetByOffset(indexInBlock, node, childEdge, identifierNumber, variant.offset()); |
| } |
| |
| void emitGetByOffset( |
| unsigned indexInBlock, Node* node, Edge childEdge, unsigned identifierNumber, |
| PropertyOffset offset, const InferredType::Descriptor& inferredType = InferredType::Top) |
| { |
| childEdge.setUseKind(KnownCellUse); |
| |
| Edge propertyStorage; |
| |
| if (isInlineOffset(offset)) |
| propertyStorage = childEdge; |
| else { |
| propertyStorage = Edge(m_insertionSet.insertNode( |
| indexInBlock, SpecNone, GetButterfly, node->origin, childEdge)); |
| } |
| |
| StorageAccessData& data = *m_graph.m_storageAccessData.add(); |
| data.offset = offset; |
| data.identifierNumber = identifierNumber; |
| data.inferredType = inferredType; |
| |
| node->convertToGetByOffset(data, propertyStorage, childEdge); |
| } |
| |
| void emitPutByOffset(unsigned indexInBlock, Node* node, const AbstractValue& baseValue, const PutByIdVariant& variant, unsigned identifierNumber) |
| { |
| NodeOrigin origin = node->origin; |
| Edge childEdge = node->child1(); |
| |
| addBaseCheck(indexInBlock, node, baseValue, variant.oldStructure()); |
| insertInferredTypeCheck( |
| m_insertionSet, indexInBlock, origin, node->child2().node(), variant.requiredType()); |
| |
| node->child1().setUseKind(KnownCellUse); |
| childEdge.setUseKind(KnownCellUse); |
| |
| Transition* transition = 0; |
| if (variant.kind() == PutByIdVariant::Transition) { |
| transition = m_graph.m_transitions.add( |
| m_graph.registerStructure(variant.oldStructureForTransition()), m_graph.registerStructure(variant.newStructure())); |
| } |
| |
| Edge propertyStorage; |
| |
| DFG_ASSERT(m_graph, node, origin.exitOK); |
| bool canExit = true; |
| bool didAllocateStorage = false; |
| |
| if (isInlineOffset(variant.offset())) |
| propertyStorage = childEdge; |
| else if (!variant.reallocatesStorage()) { |
| propertyStorage = Edge(m_insertionSet.insertNode( |
| indexInBlock, SpecNone, GetButterfly, origin, childEdge)); |
| } else if (!variant.oldStructureForTransition()->outOfLineCapacity()) { |
| ASSERT(variant.newStructure()->outOfLineCapacity()); |
| ASSERT(!isInlineOffset(variant.offset())); |
| Node* allocatePropertyStorage = m_insertionSet.insertNode( |
| indexInBlock, SpecNone, AllocatePropertyStorage, |
| origin, OpInfo(transition), childEdge); |
| propertyStorage = Edge(allocatePropertyStorage); |
| didAllocateStorage = true; |
| } else { |
| ASSERT(variant.oldStructureForTransition()->outOfLineCapacity()); |
| ASSERT(variant.newStructure()->outOfLineCapacity() > variant.oldStructureForTransition()->outOfLineCapacity()); |
| ASSERT(!isInlineOffset(variant.offset())); |
| |
| Node* reallocatePropertyStorage = m_insertionSet.insertNode( |
| indexInBlock, SpecNone, ReallocatePropertyStorage, origin, |
| OpInfo(transition), childEdge, |
| Edge(m_insertionSet.insertNode( |
| indexInBlock, SpecNone, GetButterfly, origin, childEdge))); |
| propertyStorage = Edge(reallocatePropertyStorage); |
| didAllocateStorage = true; |
| } |
| |
| StorageAccessData& data = *m_graph.m_storageAccessData.add(); |
| data.offset = variant.offset(); |
| data.identifierNumber = identifierNumber; |
| |
| node->convertToPutByOffset(data, propertyStorage, childEdge); |
| node->origin.exitOK = canExit; |
| |
| if (variant.kind() == PutByIdVariant::Transition) { |
| if (didAllocateStorage) { |
| m_insertionSet.insertNode( |
| indexInBlock + 1, SpecNone, NukeStructureAndSetButterfly, |
| origin.withInvalidExit(), childEdge, propertyStorage); |
| } |
| |
| // FIXME: PutStructure goes last until we fix either |
| // https://bugs.webkit.org/show_bug.cgi?id=142921 or |
| // https://bugs.webkit.org/show_bug.cgi?id=142924. |
| m_insertionSet.insertNode( |
| indexInBlock + 1, SpecNone, PutStructure, origin.withInvalidExit(), OpInfo(transition), |
| childEdge); |
| } |
| } |
| |
| void addBaseCheck( |
| unsigned indexInBlock, Node* node, const AbstractValue& baseValue, const StructureSet& set) |
| { |
| addBaseCheck(indexInBlock, node, baseValue, *m_graph.addStructureSet(set)); |
| } |
| |
| void addBaseCheck( |
| unsigned indexInBlock, Node* node, const AbstractValue& baseValue, const RegisteredStructureSet& set) |
| { |
| if (!baseValue.m_structure.isSubsetOf(set)) { |
| // Arises when we prune MultiGetByOffset. We could have a |
| // MultiGetByOffset with a single variant that checks for structure S, |
| // and the input has structures S and T, for example. |
| ASSERT(node->child1()); |
| m_insertionSet.insertNode( |
| indexInBlock, SpecNone, CheckStructure, node->origin, |
| OpInfo(m_graph.addStructureSet(set.toStructureSet())), node->child1()); |
| return; |
| } |
| |
| if (baseValue.m_type & ~SpecCell) |
| m_insertionSet.insertCheck(indexInBlock, node->origin, node->child1()); |
| } |
| |
| void addStructureTransitionCheck(NodeOrigin origin, unsigned indexInBlock, JSCell* cell, Structure* structure) |
| { |
| { |
| StructureRegistrationResult result; |
| m_graph.registerStructure(cell->structure(), result); |
| if (result == StructureRegisteredAndWatched) |
| return; |
| } |
| |
| m_graph.registerStructure(structure); |
| |
| Node* weakConstant = m_insertionSet.insertNode( |
| indexInBlock, speculationFromValue(cell), JSConstant, origin, |
| OpInfo(m_graph.freeze(cell))); |
| |
| m_insertionSet.insertNode( |
| indexInBlock, SpecNone, CheckStructure, origin, |
| OpInfo(m_graph.addStructureSet(structure)), Edge(weakConstant, CellUse)); |
| } |
| |
| void fixUpsilons(BasicBlock* block) |
| { |
| for (unsigned nodeIndex = block->size(); nodeIndex--;) { |
| Node* node = block->at(nodeIndex); |
| if (node->op() != Upsilon) |
| continue; |
| switch (node->phi()->op()) { |
| case Phi: |
| break; |
| case JSConstant: |
| case DoubleConstant: |
| case Int52Constant: |
| node->remove(m_graph); |
| break; |
| default: |
| DFG_CRASH(m_graph, node, "Bad Upsilon phi() pointer"); |
| break; |
| } |
| } |
| } |
| |
| InPlaceAbstractState m_state; |
| AbstractInterpreter<InPlaceAbstractState> m_interpreter; |
| InsertionSet m_insertionSet; |
| }; |
| |
| bool performConstantFolding(Graph& graph) |
| { |
| return runPhase<ConstantFoldingPhase>(graph); |
| } |
| |
| } } // namespace JSC::DFG |
| |
| #endif // ENABLE(DFG_JIT) |
| |
| |
