| // Copyright 2015 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "src/compiler/js-native-context-specialization.h" |
| |
| #include "src/accessors.h" |
| #include "src/code-factory.h" |
| #include "src/compilation-dependencies.h" |
| #include "src/compiler/access-builder.h" |
| #include "src/compiler/access-info.h" |
| #include "src/compiler/js-graph.h" |
| #include "src/compiler/js-operator.h" |
| #include "src/compiler/linkage.h" |
| #include "src/compiler/node-matchers.h" |
| #include "src/field-index-inl.h" |
| #include "src/isolate-inl.h" |
| #include "src/type-cache.h" |
| #include "src/type-feedback-vector.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace compiler { |
| |
| JSNativeContextSpecialization::JSNativeContextSpecialization( |
| Editor* editor, JSGraph* jsgraph, Flags flags, |
| MaybeHandle<Context> native_context, CompilationDependencies* dependencies, |
| Zone* zone) |
| : AdvancedReducer(editor), |
| jsgraph_(jsgraph), |
| flags_(flags), |
| native_context_(native_context), |
| dependencies_(dependencies), |
| zone_(zone), |
| type_cache_(TypeCache::Get()) {} |
| |
| |
| Reduction JSNativeContextSpecialization::Reduce(Node* node) { |
| switch (node->opcode()) { |
| case IrOpcode::kJSLoadContext: |
| return ReduceJSLoadContext(node); |
| case IrOpcode::kJSLoadNamed: |
| return ReduceJSLoadNamed(node); |
| case IrOpcode::kJSStoreNamed: |
| return ReduceJSStoreNamed(node); |
| case IrOpcode::kJSLoadProperty: |
| return ReduceJSLoadProperty(node); |
| case IrOpcode::kJSStoreProperty: |
| return ReduceJSStoreProperty(node); |
| default: |
| break; |
| } |
| return NoChange(); |
| } |
| |
| Reduction JSNativeContextSpecialization::ReduceJSLoadContext(Node* node) { |
| DCHECK_EQ(IrOpcode::kJSLoadContext, node->opcode()); |
| ContextAccess const& access = ContextAccessOf(node->op()); |
| Handle<Context> native_context; |
| // Specialize JSLoadContext(NATIVE_CONTEXT_INDEX) to the known native |
| // context (if any), so we can constant-fold those fields, which is |
| // safe, since the NATIVE_CONTEXT_INDEX slot is always immutable. |
| if (access.index() == Context::NATIVE_CONTEXT_INDEX && |
| GetNativeContext(node).ToHandle(&native_context)) { |
| Node* value = jsgraph()->HeapConstant(native_context); |
| ReplaceWithValue(node, value); |
| return Replace(value); |
| } |
| return NoChange(); |
| } |
| |
| Reduction JSNativeContextSpecialization::ReduceNamedAccess( |
| Node* node, Node* value, MapHandleList const& receiver_maps, |
| Handle<Name> name, AccessMode access_mode, LanguageMode language_mode, |
| Node* index) { |
| DCHECK(node->opcode() == IrOpcode::kJSLoadNamed || |
| node->opcode() == IrOpcode::kJSStoreNamed || |
| node->opcode() == IrOpcode::kJSLoadProperty || |
| node->opcode() == IrOpcode::kJSStoreProperty); |
| Node* receiver = NodeProperties::GetValueInput(node, 0); |
| Node* effect = NodeProperties::GetEffectInput(node); |
| Node* control = NodeProperties::GetControlInput(node); |
| Node* frame_state = NodeProperties::FindFrameStateBefore(node); |
| |
| // Not much we can do if deoptimization support is disabled. |
| if (!(flags() & kDeoptimizationEnabled)) return NoChange(); |
| |
| // Retrieve the native context from the given {node}. |
| Handle<Context> native_context; |
| if (!GetNativeContext(node).ToHandle(&native_context)) return NoChange(); |
| |
| // Compute property access infos for the receiver maps. |
| AccessInfoFactory access_info_factory(dependencies(), native_context, |
| graph()->zone()); |
| ZoneVector<PropertyAccessInfo> access_infos(zone()); |
| if (!access_info_factory.ComputePropertyAccessInfos( |
| receiver_maps, name, access_mode, &access_infos)) { |
| return NoChange(); |
| } |
| |
| // Nothing to do if we have no non-deprecated maps. |
| if (access_infos.empty()) return NoChange(); |
| |
| // The final states for every polymorphic branch. We join them with |
| // Merge++Phi+EffectPhi at the bottom. |
| ZoneVector<Node*> values(zone()); |
| ZoneVector<Node*> effects(zone()); |
| ZoneVector<Node*> controls(zone()); |
| |
| // Ensure that {index} matches the specified {name} (if {index} is given). |
| if (index != nullptr) { |
| Node* check = graph()->NewNode(simplified()->ReferenceEqual(Type::Name()), |
| index, jsgraph()->HeapConstant(name)); |
| control = effect = graph()->NewNode(common()->DeoptimizeUnless(), check, |
| frame_state, effect, control); |
| } |
| |
| // Check if {receiver} may be a number. |
| bool receiverissmi_possible = false; |
| for (PropertyAccessInfo const& access_info : access_infos) { |
| if (access_info.receiver_type()->Is(Type::Number())) { |
| receiverissmi_possible = true; |
| break; |
| } |
| } |
| |
| // Ensure that {receiver} is a heap object. |
| Node* receiverissmi_control = nullptr; |
| Node* receiverissmi_effect = effect; |
| if (receiverissmi_possible) { |
| Node* check = graph()->NewNode(simplified()->ObjectIsSmi(), receiver); |
| Node* branch = graph()->NewNode(common()->Branch(), check, control); |
| control = graph()->NewNode(common()->IfFalse(), branch); |
| receiverissmi_control = graph()->NewNode(common()->IfTrue(), branch); |
| receiverissmi_effect = effect; |
| } else { |
| receiver = effect = graph()->NewNode(simplified()->CheckTaggedPointer(), |
| receiver, effect, control); |
| } |
| |
| // Load the {receiver} map. The resulting effect is the dominating effect for |
| // all (polymorphic) branches. |
| Node* receiver_map = effect = |
| graph()->NewNode(simplified()->LoadField(AccessBuilder::ForMap()), |
| receiver, effect, control); |
| |
| // Generate code for the various different property access patterns. |
| Node* fallthrough_control = control; |
| for (size_t j = 0; j < access_infos.size(); ++j) { |
| PropertyAccessInfo const& access_info = access_infos[j]; |
| Node* this_value = value; |
| Node* this_receiver = receiver; |
| Node* this_effect = effect; |
| Node* this_control; |
| |
| // Perform map check on {receiver}. |
| Type* receiver_type = access_info.receiver_type(); |
| if (receiver_type->Is(Type::String())) { |
| Node* check = graph()->NewNode(simplified()->ObjectIsString(), receiver); |
| if (j == access_infos.size() - 1) { |
| this_control = this_effect = |
| graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state, |
| this_effect, fallthrough_control); |
| fallthrough_control = nullptr; |
| } else { |
| Node* branch = |
| graph()->NewNode(common()->Branch(), check, fallthrough_control); |
| fallthrough_control = graph()->NewNode(common()->IfFalse(), branch); |
| this_control = graph()->NewNode(common()->IfTrue(), branch); |
| } |
| } else { |
| // Emit a (sequence of) map checks for other {receiver}s. |
| ZoneVector<Node*> this_controls(zone()); |
| ZoneVector<Node*> this_effects(zone()); |
| int num_classes = access_info.receiver_type()->NumClasses(); |
| for (auto i = access_info.receiver_type()->Classes(); !i.Done(); |
| i.Advance()) { |
| DCHECK_LT(0, num_classes); |
| Handle<Map> map = i.Current(); |
| Node* check = |
| graph()->NewNode(simplified()->ReferenceEqual(Type::Internal()), |
| receiver_map, jsgraph()->Constant(map)); |
| if (--num_classes == 0 && j == access_infos.size() - 1) { |
| Node* deoptimize = |
| graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state, |
| this_effect, fallthrough_control); |
| this_controls.push_back(deoptimize); |
| this_effects.push_back(deoptimize); |
| fallthrough_control = nullptr; |
| } else { |
| Node* branch = |
| graph()->NewNode(common()->Branch(), check, fallthrough_control); |
| fallthrough_control = graph()->NewNode(common()->IfFalse(), branch); |
| this_controls.push_back(graph()->NewNode(common()->IfTrue(), branch)); |
| this_effects.push_back(this_effect); |
| } |
| } |
| |
| // The Number case requires special treatment to also deal with Smis. |
| if (receiver_type->Is(Type::Number())) { |
| // Join this check with the "receiver is smi" check above. |
| DCHECK_NOT_NULL(receiverissmi_effect); |
| DCHECK_NOT_NULL(receiverissmi_control); |
| this_effects.push_back(receiverissmi_effect); |
| this_controls.push_back(receiverissmi_control); |
| receiverissmi_effect = receiverissmi_control = nullptr; |
| } |
| |
| // Create dominating Merge+EffectPhi for this {receiver} type. |
| int const this_control_count = static_cast<int>(this_controls.size()); |
| this_control = |
| (this_control_count == 1) |
| ? this_controls.front() |
| : graph()->NewNode(common()->Merge(this_control_count), |
| this_control_count, &this_controls.front()); |
| this_effects.push_back(this_control); |
| int const this_effect_count = static_cast<int>(this_effects.size()); |
| this_effect = |
| (this_control_count == 1) |
| ? this_effects.front() |
| : graph()->NewNode(common()->EffectPhi(this_control_count), |
| this_effect_count, &this_effects.front()); |
| } |
| |
| // Determine actual holder and perform prototype chain checks. |
| Handle<JSObject> holder; |
| if (access_info.holder().ToHandle(&holder)) { |
| AssumePrototypesStable(receiver_type, native_context, holder); |
| } |
| |
| // Generate the actual property access. |
| if (access_info.IsNotFound()) { |
| DCHECK_EQ(AccessMode::kLoad, access_mode); |
| this_value = jsgraph()->UndefinedConstant(); |
| } else if (access_info.IsDataConstant()) { |
| this_value = jsgraph()->Constant(access_info.constant()); |
| if (access_mode == AccessMode::kStore) { |
| Node* check = graph()->NewNode( |
| simplified()->ReferenceEqual(Type::Tagged()), value, this_value); |
| this_control = this_effect = |
| graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state, |
| this_effect, this_control); |
| } |
| } else { |
| DCHECK(access_info.IsDataField()); |
| FieldIndex const field_index = access_info.field_index(); |
| Type* const field_type = access_info.field_type(); |
| if (access_mode == AccessMode::kLoad && |
| access_info.holder().ToHandle(&holder)) { |
| this_receiver = jsgraph()->Constant(holder); |
| } |
| Node* this_storage = this_receiver; |
| if (!field_index.is_inobject()) { |
| this_storage = this_effect = graph()->NewNode( |
| simplified()->LoadField(AccessBuilder::ForJSObjectProperties()), |
| this_storage, this_effect, this_control); |
| } |
| FieldAccess field_access = { |
| kTaggedBase, field_index.offset(), name, |
| field_type, MachineType::AnyTagged(), kFullWriteBarrier}; |
| if (access_mode == AccessMode::kLoad) { |
| if (field_type->Is(Type::UntaggedFloat64())) { |
| // TODO(turbofan): We remove the representation axis from the type to |
| // avoid uninhabited representation types. This is a workaround until |
| // the {PropertyAccessInfo} is using {MachineRepresentation} instead. |
| field_access.type = Type::Union( |
| field_type, Type::Representation(Type::Number(), zone()), zone()); |
| if (!field_index.is_inobject() || field_index.is_hidden_field() || |
| !FLAG_unbox_double_fields) { |
| this_storage = this_effect = |
| graph()->NewNode(simplified()->LoadField(field_access), |
| this_storage, this_effect, this_control); |
| field_access.offset = HeapNumber::kValueOffset; |
| field_access.name = MaybeHandle<Name>(); |
| } |
| field_access.machine_type = MachineType::Float64(); |
| } |
| this_value = this_effect = |
| graph()->NewNode(simplified()->LoadField(field_access), |
| this_storage, this_effect, this_control); |
| } else { |
| DCHECK_EQ(AccessMode::kStore, access_mode); |
| if (field_type->Is(Type::UntaggedFloat64())) { |
| // TODO(turbofan): We remove the representation axis from the type to |
| // avoid uninhabited representation types. This is a workaround until |
| // the {PropertyAccessInfo} is using {MachineRepresentation} instead. |
| field_access.type = Type::Union( |
| field_type, Type::Representation(Type::Number(), zone()), zone()); |
| Node* check = |
| graph()->NewNode(simplified()->ObjectIsNumber(), this_value); |
| this_control = this_effect = |
| graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state, |
| this_effect, this_control); |
| this_value = graph()->NewNode(simplified()->TypeGuard(Type::Number()), |
| this_value, this_control); |
| |
| if (!field_index.is_inobject() || field_index.is_hidden_field() || |
| !FLAG_unbox_double_fields) { |
| if (access_info.HasTransitionMap()) { |
| // Allocate a MutableHeapNumber for the new property. |
| this_effect = graph()->NewNode( |
| common()->BeginRegion(RegionObservability::kNotObservable), |
| this_effect); |
| Node* this_box = this_effect = |
| graph()->NewNode(simplified()->Allocate(NOT_TENURED), |
| jsgraph()->Constant(HeapNumber::kSize), |
| this_effect, this_control); |
| this_effect = graph()->NewNode( |
| simplified()->StoreField(AccessBuilder::ForMap()), this_box, |
| jsgraph()->HeapConstant(factory()->mutable_heap_number_map()), |
| this_effect, this_control); |
| this_effect = graph()->NewNode( |
| simplified()->StoreField(AccessBuilder::ForHeapNumberValue()), |
| this_box, this_value, this_effect, this_control); |
| this_value = this_effect = graph()->NewNode( |
| common()->FinishRegion(), this_box, this_effect); |
| |
| field_access.type = Type::TaggedPointer(); |
| } else { |
| // We just store directly to the MutableHeapNumber. |
| this_storage = this_effect = |
| graph()->NewNode(simplified()->LoadField(field_access), |
| this_storage, this_effect, this_control); |
| field_access.offset = HeapNumber::kValueOffset; |
| field_access.name = MaybeHandle<Name>(); |
| field_access.machine_type = MachineType::Float64(); |
| } |
| } else { |
| // Unboxed double field, we store directly to the field. |
| field_access.machine_type = MachineType::Float64(); |
| } |
| } else if (field_type->Is(Type::TaggedSigned())) { |
| this_value = this_effect = |
| graph()->NewNode(simplified()->CheckTaggedSigned(), this_value, |
| this_effect, this_control); |
| } else if (field_type->Is(Type::TaggedPointer())) { |
| this_value = this_effect = |
| graph()->NewNode(simplified()->CheckTaggedPointer(), this_value, |
| this_effect, this_control); |
| if (field_type->NumClasses() == 1) { |
| // Emit a map check for the value. |
| Node* this_value_map = this_effect = graph()->NewNode( |
| simplified()->LoadField(AccessBuilder::ForMap()), this_value, |
| this_effect, this_control); |
| Node* check = graph()->NewNode( |
| simplified()->ReferenceEqual(Type::Internal()), this_value_map, |
| jsgraph()->Constant(field_type->Classes().Current())); |
| this_control = this_effect = |
| graph()->NewNode(common()->DeoptimizeUnless(), check, |
| frame_state, this_effect, this_control); |
| } else { |
| DCHECK_EQ(0, field_type->NumClasses()); |
| } |
| } else { |
| DCHECK(field_type->Is(Type::Tagged())); |
| } |
| Handle<Map> transition_map; |
| if (access_info.transition_map().ToHandle(&transition_map)) { |
| this_effect = graph()->NewNode( |
| common()->BeginRegion(RegionObservability::kObservable), |
| this_effect); |
| this_effect = graph()->NewNode( |
| simplified()->StoreField(AccessBuilder::ForMap()), this_receiver, |
| jsgraph()->Constant(transition_map), this_effect, this_control); |
| } |
| this_effect = graph()->NewNode(simplified()->StoreField(field_access), |
| this_storage, this_value, this_effect, |
| this_control); |
| if (access_info.HasTransitionMap()) { |
| this_effect = |
| graph()->NewNode(common()->FinishRegion(), |
| jsgraph()->UndefinedConstant(), this_effect); |
| } |
| } |
| } |
| |
| // Remember the final state for this property access. |
| values.push_back(this_value); |
| effects.push_back(this_effect); |
| controls.push_back(this_control); |
| } |
| |
| DCHECK_NULL(fallthrough_control); |
| |
| // Generate the final merge point for all (polymorphic) branches. |
| int const control_count = static_cast<int>(controls.size()); |
| if (control_count == 0) { |
| value = effect = control = jsgraph()->Dead(); |
| } else if (control_count == 1) { |
| value = values.front(); |
| effect = effects.front(); |
| control = controls.front(); |
| } else { |
| control = graph()->NewNode(common()->Merge(control_count), control_count, |
| &controls.front()); |
| values.push_back(control); |
| value = graph()->NewNode( |
| common()->Phi(MachineRepresentation::kTagged, control_count), |
| control_count + 1, &values.front()); |
| effects.push_back(control); |
| effect = graph()->NewNode(common()->EffectPhi(control_count), |
| control_count + 1, &effects.front()); |
| } |
| ReplaceWithValue(node, value, effect, control); |
| return Replace(value); |
| } |
| |
| |
| Reduction JSNativeContextSpecialization::ReduceNamedAccess( |
| Node* node, Node* value, FeedbackNexus const& nexus, Handle<Name> name, |
| AccessMode access_mode, LanguageMode language_mode) { |
| DCHECK(node->opcode() == IrOpcode::kJSLoadNamed || |
| node->opcode() == IrOpcode::kJSStoreNamed); |
| Node* const receiver = NodeProperties::GetValueInput(node, 0); |
| Node* const effect = NodeProperties::GetEffectInput(node); |
| |
| // Check if the {nexus} reports type feedback for the IC. |
| if (nexus.IsUninitialized()) { |
| if ((flags() & kDeoptimizationEnabled) && |
| (flags() & kBailoutOnUninitialized)) { |
| return ReduceSoftDeoptimize(node); |
| } |
| return NoChange(); |
| } |
| |
| // Extract receiver maps from the IC using the {nexus}. |
| MapHandleList receiver_maps; |
| if (!ExtractReceiverMaps(receiver, effect, nexus, &receiver_maps)) { |
| return NoChange(); |
| } else if (receiver_maps.length() == 0) { |
| if ((flags() & kDeoptimizationEnabled) && |
| (flags() & kBailoutOnUninitialized)) { |
| return ReduceSoftDeoptimize(node); |
| } |
| return NoChange(); |
| } |
| |
| // Try to lower the named access based on the {receiver_maps}. |
| return ReduceNamedAccess(node, value, receiver_maps, name, access_mode, |
| language_mode); |
| } |
| |
| |
| Reduction JSNativeContextSpecialization::ReduceJSLoadNamed(Node* node) { |
| DCHECK_EQ(IrOpcode::kJSLoadNamed, node->opcode()); |
| NamedAccess const& p = NamedAccessOf(node->op()); |
| Node* const receiver = NodeProperties::GetValueInput(node, 0); |
| Node* const value = jsgraph()->Dead(); |
| |
| // Check if we have a constant receiver. |
| HeapObjectMatcher m(receiver); |
| if (m.HasValue()) { |
| // Optimize "prototype" property of functions. |
| if (m.Value()->IsJSFunction() && |
| p.name().is_identical_to(factory()->prototype_string())) { |
| Handle<JSFunction> function = Handle<JSFunction>::cast(m.Value()); |
| if (function->has_initial_map()) { |
| // We need to add a code dependency on the initial map of the |
| // {function} in order to be notified about changes to the |
| // "prototype" of {function}, so it doesn't make sense to |
| // continue unless deoptimization is enabled. |
| if (flags() & kDeoptimizationEnabled) { |
| Handle<Map> initial_map(function->initial_map(), isolate()); |
| dependencies()->AssumeInitialMapCantChange(initial_map); |
| Handle<Object> prototype(initial_map->prototype(), isolate()); |
| Node* value = jsgraph()->Constant(prototype); |
| ReplaceWithValue(node, value); |
| return Replace(value); |
| } |
| } |
| } |
| } |
| |
| // Extract receiver maps from the LOAD_IC using the LoadICNexus. |
| if (!p.feedback().IsValid()) return NoChange(); |
| LoadICNexus nexus(p.feedback().vector(), p.feedback().slot()); |
| |
| // Try to lower the named access based on the {receiver_maps}. |
| return ReduceNamedAccess(node, value, nexus, p.name(), AccessMode::kLoad, |
| p.language_mode()); |
| } |
| |
| |
| Reduction JSNativeContextSpecialization::ReduceJSStoreNamed(Node* node) { |
| DCHECK_EQ(IrOpcode::kJSStoreNamed, node->opcode()); |
| NamedAccess const& p = NamedAccessOf(node->op()); |
| Node* const value = NodeProperties::GetValueInput(node, 1); |
| |
| // Extract receiver maps from the STORE_IC using the StoreICNexus. |
| if (!p.feedback().IsValid()) return NoChange(); |
| StoreICNexus nexus(p.feedback().vector(), p.feedback().slot()); |
| |
| // Try to lower the named access based on the {receiver_maps}. |
| return ReduceNamedAccess(node, value, nexus, p.name(), AccessMode::kStore, |
| p.language_mode()); |
| } |
| |
| |
| Reduction JSNativeContextSpecialization::ReduceElementAccess( |
| Node* node, Node* index, Node* value, MapHandleList const& receiver_maps, |
| AccessMode access_mode, LanguageMode language_mode, |
| KeyedAccessStoreMode store_mode) { |
| DCHECK(node->opcode() == IrOpcode::kJSLoadProperty || |
| node->opcode() == IrOpcode::kJSStoreProperty); |
| Node* receiver = NodeProperties::GetValueInput(node, 0); |
| Node* context = NodeProperties::GetContextInput(node); |
| Node* effect = NodeProperties::GetEffectInput(node); |
| Node* control = NodeProperties::GetControlInput(node); |
| Node* frame_state = NodeProperties::FindFrameStateBefore(node); |
| |
| // Not much we can do if deoptimization support is disabled. |
| if (!(flags() & kDeoptimizationEnabled)) return NoChange(); |
| |
| // TODO(bmeurer): Add support for non-standard stores. |
| if (store_mode != STANDARD_STORE) return NoChange(); |
| |
| // Retrieve the native context from the given {node}. |
| Handle<Context> native_context; |
| if (!GetNativeContext(node).ToHandle(&native_context)) return NoChange(); |
| |
| // Compute element access infos for the receiver maps. |
| AccessInfoFactory access_info_factory(dependencies(), native_context, |
| graph()->zone()); |
| ZoneVector<ElementAccessInfo> access_infos(zone()); |
| if (!access_info_factory.ComputeElementAccessInfos(receiver_maps, access_mode, |
| &access_infos)) { |
| return NoChange(); |
| } |
| |
| // Nothing to do if we have no non-deprecated maps. |
| if (access_infos.empty()) return NoChange(); |
| |
| // The final states for every polymorphic branch. We join them with |
| // Merge+Phi+EffectPhi at the bottom. |
| ZoneVector<Node*> values(zone()); |
| ZoneVector<Node*> effects(zone()); |
| ZoneVector<Node*> controls(zone()); |
| |
| // Ensure that {receiver} is a heap object. |
| receiver = effect = graph()->NewNode(simplified()->CheckTaggedPointer(), |
| receiver, effect, control); |
| |
| // Load the {receiver} map. The resulting effect is the dominating effect for |
| // all (polymorphic) branches. |
| Node* receiver_map = effect = |
| graph()->NewNode(simplified()->LoadField(AccessBuilder::ForMap()), |
| receiver, effect, control); |
| |
| // Generate code for the various different element access patterns. |
| Node* fallthrough_control = control; |
| for (size_t j = 0; j < access_infos.size(); ++j) { |
| ElementAccessInfo const& access_info = access_infos[j]; |
| Node* this_receiver = receiver; |
| Node* this_value = value; |
| Node* this_index = index; |
| Node* this_effect; |
| Node* this_control; |
| |
| // Perform map check on {receiver}. |
| Type* receiver_type = access_info.receiver_type(); |
| bool receiver_is_jsarray = true; |
| { |
| ZoneVector<Node*> this_controls(zone()); |
| ZoneVector<Node*> this_effects(zone()); |
| size_t num_transitions = access_info.transitions().size(); |
| int num_classes = access_info.receiver_type()->NumClasses(); |
| for (auto i = access_info.receiver_type()->Classes(); !i.Done(); |
| i.Advance()) { |
| DCHECK_LT(0, num_classes); |
| Handle<Map> map = i.Current(); |
| Node* check = |
| graph()->NewNode(simplified()->ReferenceEqual(Type::Any()), |
| receiver_map, jsgraph()->Constant(map)); |
| if (--num_classes == 0 && num_transitions == 0 && |
| j == access_infos.size() - 1) { |
| // Last map check on the fallthrough control path, do a conditional |
| // eager deoptimization exit here. |
| // TODO(turbofan): This is ugly as hell! We should probably introduce |
| // macro-ish operators for property access that encapsulate this whole |
| // mess. |
| Node* deoptimize = |
| graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state, |
| effect, fallthrough_control); |
| this_controls.push_back(deoptimize); |
| this_effects.push_back(deoptimize); |
| fallthrough_control = nullptr; |
| } else { |
| Node* branch = |
| graph()->NewNode(common()->Branch(), check, fallthrough_control); |
| this_controls.push_back(graph()->NewNode(common()->IfTrue(), branch)); |
| this_effects.push_back(effect); |
| fallthrough_control = graph()->NewNode(common()->IfFalse(), branch); |
| } |
| if (!map->IsJSArrayMap()) receiver_is_jsarray = false; |
| } |
| |
| // Generate possible elements kind transitions. |
| for (auto transition : access_info.transitions()) { |
| DCHECK_LT(0u, num_transitions); |
| Handle<Map> transition_source = transition.first; |
| Handle<Map> transition_target = transition.second; |
| Node* transition_control; |
| Node* transition_effect = effect; |
| |
| // Check if {receiver} has the specified {transition_source} map. |
| Node* check = graph()->NewNode( |
| simplified()->ReferenceEqual(Type::Any()), receiver_map, |
| jsgraph()->HeapConstant(transition_source)); |
| if (--num_transitions == 0 && j == access_infos.size() - 1) { |
| transition_control = transition_effect = |
| graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state, |
| transition_effect, fallthrough_control); |
| fallthrough_control = nullptr; |
| } else { |
| Node* branch = |
| graph()->NewNode(common()->Branch(), check, fallthrough_control); |
| fallthrough_control = graph()->NewNode(common()->IfFalse(), branch); |
| transition_control = graph()->NewNode(common()->IfTrue(), branch); |
| } |
| |
| // Migrate {receiver} from {transition_source} to {transition_target}. |
| if (IsSimpleMapChangeTransition(transition_source->elements_kind(), |
| transition_target->elements_kind())) { |
| // In-place migration, just store the {transition_target} map. |
| transition_effect = graph()->NewNode( |
| simplified()->StoreField(AccessBuilder::ForMap()), receiver, |
| jsgraph()->HeapConstant(transition_target), transition_effect, |
| transition_control); |
| } else { |
| // Instance migration, let the stub deal with the {receiver}. |
| TransitionElementsKindStub stub(isolate(), |
| transition_source->elements_kind(), |
| transition_target->elements_kind()); |
| CallDescriptor const* const desc = Linkage::GetStubCallDescriptor( |
| isolate(), graph()->zone(), stub.GetCallInterfaceDescriptor(), 0, |
| CallDescriptor::kNeedsFrameState, node->op()->properties()); |
| transition_effect = graph()->NewNode( |
| common()->Call(desc), jsgraph()->HeapConstant(stub.GetCode()), |
| receiver, jsgraph()->HeapConstant(transition_target), context, |
| frame_state, transition_effect, transition_control); |
| } |
| |
| this_controls.push_back(transition_control); |
| this_effects.push_back(transition_effect); |
| } |
| |
| // Create single chokepoint for the control. |
| int const this_control_count = static_cast<int>(this_controls.size()); |
| if (this_control_count == 1) { |
| this_control = this_controls.front(); |
| this_effect = this_effects.front(); |
| } else { |
| this_control = |
| graph()->NewNode(common()->Merge(this_control_count), |
| this_control_count, &this_controls.front()); |
| this_effects.push_back(this_control); |
| this_effect = |
| graph()->NewNode(common()->EffectPhi(this_control_count), |
| this_control_count + 1, &this_effects.front()); |
| } |
| |
| // TODO(turbofan): The effect/control linearization will not find a |
| // FrameState after the StoreField or Call that is generated for the |
| // elements kind transition above. This is because those operators |
| // don't have the kNoWrite flag on it, even though they are not |
| // observable by JavaScript. |
| this_effect = graph()->NewNode(common()->Checkpoint(), frame_state, |
| this_effect, this_control); |
| } |
| |
| // Certain stores need a prototype chain check because shape changes |
| // could allow callbacks on elements in the prototype chain that are |
| // not compatible with (monomorphic) keyed stores. |
| Handle<JSObject> holder; |
| if (access_info.holder().ToHandle(&holder)) { |
| AssumePrototypesStable(receiver_type, native_context, holder); |
| } |
| |
| // TODO(bmeurer): We currently specialize based on elements kind. We should |
| // also be able to properly support strings and other JSObjects here. |
| ElementsKind elements_kind = access_info.elements_kind(); |
| |
| // Load the elements for the {receiver}. |
| Node* this_elements = this_effect = graph()->NewNode( |
| simplified()->LoadField(AccessBuilder::ForJSObjectElements()), |
| this_receiver, this_effect, this_control); |
| |
| // Don't try to store to a copy-on-write backing store. |
| if (access_mode == AccessMode::kStore && |
| IsFastSmiOrObjectElementsKind(elements_kind)) { |
| Node* this_elements_map = this_effect = |
| graph()->NewNode(simplified()->LoadField(AccessBuilder::ForMap()), |
| this_elements, this_effect, this_control); |
| Node* check = graph()->NewNode( |
| simplified()->ReferenceEqual(Type::Any()), this_elements_map, |
| jsgraph()->HeapConstant(factory()->fixed_array_map())); |
| this_control = this_effect = |
| graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state, |
| this_effect, this_control); |
| } |
| |
| // Load the length of the {receiver}. |
| Node* this_length = this_effect = |
| receiver_is_jsarray |
| ? graph()->NewNode( |
| simplified()->LoadField( |
| AccessBuilder::ForJSArrayLength(elements_kind)), |
| this_receiver, this_effect, this_control) |
| : graph()->NewNode( |
| simplified()->LoadField(AccessBuilder::ForFixedArrayLength()), |
| this_elements, this_effect, this_control); |
| |
| // Check that the {index} is in the valid range for the {receiver}. |
| this_index = this_effect = |
| graph()->NewNode(simplified()->CheckBounds(), this_index, this_length, |
| this_effect, this_control); |
| |
| // Compute the element access. |
| Type* element_type = Type::Any(); |
| MachineType element_machine_type = MachineType::AnyTagged(); |
| if (IsFastDoubleElementsKind(elements_kind)) { |
| element_type = Type::Number(); |
| element_machine_type = MachineType::Float64(); |
| } else if (IsFastSmiElementsKind(elements_kind)) { |
| element_type = type_cache_.kSmi; |
| } |
| ElementAccess element_access = {kTaggedBase, FixedArray::kHeaderSize, |
| element_type, element_machine_type, |
| kFullWriteBarrier}; |
| |
| // Access the actual element. |
| // TODO(bmeurer): Refactor this into separate methods or even a separate |
| // class that deals with the elements access. |
| if (access_mode == AccessMode::kLoad) { |
| // Compute the real element access type, which includes the hole in case |
| // of holey backing stores. |
| if (elements_kind == FAST_HOLEY_ELEMENTS || |
| elements_kind == FAST_HOLEY_SMI_ELEMENTS) { |
| element_access.type = Type::Union( |
| element_type, |
| Type::Constant(factory()->the_hole_value(), graph()->zone()), |
| graph()->zone()); |
| } |
| // Perform the actual backing store access. |
| this_value = this_effect = graph()->NewNode( |
| simplified()->LoadElement(element_access), this_elements, this_index, |
| this_effect, this_control); |
| // Handle loading from holey backing stores correctly, by either mapping |
| // the hole to undefined if possible, or deoptimizing otherwise. |
| if (elements_kind == FAST_HOLEY_ELEMENTS || |
| elements_kind == FAST_HOLEY_SMI_ELEMENTS) { |
| // Perform the hole check on the result. |
| CheckTaggedHoleMode mode = CheckTaggedHoleMode::kNeverReturnHole; |
| // Check if we are allowed to turn the hole into undefined. |
| Type* initial_holey_array_type = Type::Class( |
| handle(isolate()->get_initial_js_array_map(elements_kind)), |
| graph()->zone()); |
| if (receiver_type->NowIs(initial_holey_array_type) && |
| isolate()->IsFastArrayConstructorPrototypeChainIntact()) { |
| // Add a code dependency on the array protector cell. |
| AssumePrototypesStable(receiver_type, native_context, |
| isolate()->initial_object_prototype()); |
| dependencies()->AssumePropertyCell(factory()->array_protector()); |
| // Turn the hole into undefined. |
| mode = CheckTaggedHoleMode::kConvertHoleToUndefined; |
| } |
| this_value = this_effect = |
| graph()->NewNode(simplified()->CheckTaggedHole(mode), this_value, |
| this_effect, this_control); |
| } else if (elements_kind == FAST_HOLEY_DOUBLE_ELEMENTS) { |
| // Perform the hole check on the result. |
| CheckFloat64HoleMode mode = CheckFloat64HoleMode::kNeverReturnHole; |
| // Check if we are allowed to return the hole directly. |
| Type* initial_holey_array_type = Type::Class( |
| handle(isolate()->get_initial_js_array_map(elements_kind)), |
| graph()->zone()); |
| if (receiver_type->NowIs(initial_holey_array_type) && |
| isolate()->IsFastArrayConstructorPrototypeChainIntact()) { |
| // Add a code dependency on the array protector cell. |
| AssumePrototypesStable(receiver_type, native_context, |
| isolate()->initial_object_prototype()); |
| dependencies()->AssumePropertyCell(factory()->array_protector()); |
| // Return the signaling NaN hole directly if all uses are truncating. |
| mode = CheckFloat64HoleMode::kAllowReturnHole; |
| } |
| this_value = this_effect = |
| graph()->NewNode(simplified()->CheckFloat64Hole(mode), this_value, |
| this_effect, this_control); |
| } |
| } else { |
| DCHECK_EQ(AccessMode::kStore, access_mode); |
| if (IsFastSmiElementsKind(elements_kind)) { |
| this_value = this_effect = |
| graph()->NewNode(simplified()->CheckTaggedSigned(), this_value, |
| this_effect, this_control); |
| } else if (IsFastDoubleElementsKind(elements_kind)) { |
| Node* check = |
| graph()->NewNode(simplified()->ObjectIsNumber(), this_value); |
| this_control = this_effect = |
| graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state, |
| this_effect, this_control); |
| this_value = graph()->NewNode(simplified()->TypeGuard(Type::Number()), |
| this_value, this_control); |
| // Make sure we do not store signalling NaNs into holey double arrays. |
| if (elements_kind == FAST_HOLEY_DOUBLE_ELEMENTS) { |
| this_value = |
| graph()->NewNode(simplified()->NumberSilenceNaN(), this_value); |
| } |
| } |
| this_effect = graph()->NewNode(simplified()->StoreElement(element_access), |
| this_elements, this_index, this_value, |
| this_effect, this_control); |
| } |
| |
| // Remember the final state for this element access. |
| values.push_back(this_value); |
| effects.push_back(this_effect); |
| controls.push_back(this_control); |
| } |
| |
| DCHECK_NULL(fallthrough_control); |
| |
| // Generate the final merge point for all (polymorphic) branches. |
| int const control_count = static_cast<int>(controls.size()); |
| if (control_count == 0) { |
| value = effect = control = jsgraph()->Dead(); |
| } else if (control_count == 1) { |
| value = values.front(); |
| effect = effects.front(); |
| control = controls.front(); |
| } else { |
| control = graph()->NewNode(common()->Merge(control_count), control_count, |
| &controls.front()); |
| values.push_back(control); |
| value = graph()->NewNode( |
| common()->Phi(MachineRepresentation::kTagged, control_count), |
| control_count + 1, &values.front()); |
| effects.push_back(control); |
| effect = graph()->NewNode(common()->EffectPhi(control_count), |
| control_count + 1, &effects.front()); |
| } |
| ReplaceWithValue(node, value, effect, control); |
| return Replace(value); |
| } |
| |
| |
| Reduction JSNativeContextSpecialization::ReduceKeyedAccess( |
| Node* node, Node* index, Node* value, FeedbackNexus const& nexus, |
| AccessMode access_mode, LanguageMode language_mode, |
| KeyedAccessStoreMode store_mode) { |
| DCHECK(node->opcode() == IrOpcode::kJSLoadProperty || |
| node->opcode() == IrOpcode::kJSStoreProperty); |
| Node* const receiver = NodeProperties::GetValueInput(node, 0); |
| Node* const effect = NodeProperties::GetEffectInput(node); |
| |
| // Check if the {nexus} reports type feedback for the IC. |
| if (nexus.IsUninitialized()) { |
| if ((flags() & kDeoptimizationEnabled) && |
| (flags() & kBailoutOnUninitialized)) { |
| return ReduceSoftDeoptimize(node); |
| } |
| return NoChange(); |
| } |
| |
| // Extract receiver maps from the {nexus}. |
| MapHandleList receiver_maps; |
| if (!ExtractReceiverMaps(receiver, effect, nexus, &receiver_maps)) { |
| return NoChange(); |
| } else if (receiver_maps.length() == 0) { |
| if ((flags() & kDeoptimizationEnabled) && |
| (flags() & kBailoutOnUninitialized)) { |
| return ReduceSoftDeoptimize(node); |
| } |
| return NoChange(); |
| } |
| |
| // Optimize access for constant {index}. |
| HeapObjectMatcher mindex(index); |
| if (mindex.HasValue() && mindex.Value()->IsPrimitive()) { |
| // Keyed access requires a ToPropertyKey on the {index} first before |
| // looking up the property on the object (see ES6 section 12.3.2.1). |
| // We can only do this for non-observable ToPropertyKey invocations, |
| // so we limit the constant indices to primitives at this point. |
| Handle<Name> name; |
| if (Object::ToName(isolate(), mindex.Value()).ToHandle(&name)) { |
| uint32_t array_index; |
| if (name->AsArrayIndex(&array_index)) { |
| // Use the constant array index. |
| index = jsgraph()->Constant(static_cast<double>(array_index)); |
| } else { |
| name = factory()->InternalizeName(name); |
| return ReduceNamedAccess(node, value, receiver_maps, name, access_mode, |
| language_mode); |
| } |
| } |
| } |
| |
| // Check if we have feedback for a named access. |
| if (Name* name = nexus.FindFirstName()) { |
| return ReduceNamedAccess(node, value, receiver_maps, |
| handle(name, isolate()), access_mode, |
| language_mode, index); |
| } |
| |
| // Try to lower the element access based on the {receiver_maps}. |
| return ReduceElementAccess(node, index, value, receiver_maps, access_mode, |
| language_mode, store_mode); |
| } |
| |
| |
| Reduction JSNativeContextSpecialization::ReduceSoftDeoptimize(Node* node) { |
| Node* effect = NodeProperties::GetEffectInput(node); |
| Node* control = NodeProperties::GetControlInput(node); |
| Node* frame_state = NodeProperties::FindFrameStateBefore(node); |
| Node* deoptimize = |
| graph()->NewNode(common()->Deoptimize(DeoptimizeKind::kSoft), frame_state, |
| effect, control); |
| // TODO(bmeurer): This should be on the AdvancedReducer somehow. |
| NodeProperties::MergeControlToEnd(graph(), common(), deoptimize); |
| Revisit(graph()->end()); |
| node->TrimInputCount(0); |
| NodeProperties::ChangeOp(node, common()->Dead()); |
| return Changed(node); |
| } |
| |
| |
| Reduction JSNativeContextSpecialization::ReduceJSLoadProperty(Node* node) { |
| DCHECK_EQ(IrOpcode::kJSLoadProperty, node->opcode()); |
| PropertyAccess const& p = PropertyAccessOf(node->op()); |
| Node* const index = NodeProperties::GetValueInput(node, 1); |
| Node* const value = jsgraph()->Dead(); |
| |
| // Extract receiver maps from the KEYED_LOAD_IC using the KeyedLoadICNexus. |
| if (!p.feedback().IsValid()) return NoChange(); |
| KeyedLoadICNexus nexus(p.feedback().vector(), p.feedback().slot()); |
| |
| // Try to lower the keyed access based on the {nexus}. |
| return ReduceKeyedAccess(node, index, value, nexus, AccessMode::kLoad, |
| p.language_mode(), STANDARD_STORE); |
| } |
| |
| |
| Reduction JSNativeContextSpecialization::ReduceJSStoreProperty(Node* node) { |
| DCHECK_EQ(IrOpcode::kJSStoreProperty, node->opcode()); |
| PropertyAccess const& p = PropertyAccessOf(node->op()); |
| Node* const index = NodeProperties::GetValueInput(node, 1); |
| Node* const value = NodeProperties::GetValueInput(node, 2); |
| |
| // Extract receiver maps from the KEYED_STORE_IC using the KeyedStoreICNexus. |
| if (!p.feedback().IsValid()) return NoChange(); |
| KeyedStoreICNexus nexus(p.feedback().vector(), p.feedback().slot()); |
| |
| // Extract the keyed access store mode from the KEYED_STORE_IC. |
| KeyedAccessStoreMode store_mode = nexus.GetKeyedAccessStoreMode(); |
| |
| // Try to lower the keyed access based on the {nexus}. |
| return ReduceKeyedAccess(node, index, value, nexus, AccessMode::kStore, |
| p.language_mode(), store_mode); |
| } |
| |
| |
| void JSNativeContextSpecialization::AssumePrototypesStable( |
| Type* receiver_type, Handle<Context> native_context, |
| Handle<JSObject> holder) { |
| // Determine actual holder and perform prototype chain checks. |
| for (auto i = receiver_type->Classes(); !i.Done(); i.Advance()) { |
| Handle<Map> map = i.Current(); |
| // Perform the implicit ToObject for primitives here. |
| // Implemented according to ES6 section 7.3.2 GetV (V, P). |
| Handle<JSFunction> constructor; |
| if (Map::GetConstructorFunction(map, native_context) |
| .ToHandle(&constructor)) { |
| map = handle(constructor->initial_map(), isolate()); |
| } |
| dependencies()->AssumePrototypeMapsStable(map, holder); |
| } |
| } |
| |
| bool JSNativeContextSpecialization::ExtractReceiverMaps( |
| Node* receiver, Node* effect, FeedbackNexus const& nexus, |
| MapHandleList* receiver_maps) { |
| DCHECK_EQ(0, receiver_maps->length()); |
| // See if we can infer a concrete type for the {receiver}. |
| Handle<Map> receiver_map; |
| if (InferReceiverMap(receiver, effect).ToHandle(&receiver_map)) { |
| // We can assume that the {receiver} still has the infered {receiver_map}. |
| receiver_maps->Add(receiver_map); |
| return true; |
| } |
| // Try to extract some maps from the {nexus}. |
| if (nexus.ExtractMaps(receiver_maps) != 0) { |
| // Try to filter impossible candidates based on infered root map. |
| if (InferReceiverRootMap(receiver).ToHandle(&receiver_map)) { |
| for (int i = receiver_maps->length(); --i >= 0;) { |
| if (receiver_maps->at(i)->FindRootMap() != *receiver_map) { |
| receiver_maps->Remove(i); |
| } |
| } |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| MaybeHandle<Map> JSNativeContextSpecialization::InferReceiverMap(Node* receiver, |
| Node* effect) { |
| NodeMatcher m(receiver); |
| if (m.IsJSCreate()) { |
| HeapObjectMatcher mtarget(m.InputAt(0)); |
| HeapObjectMatcher mnewtarget(m.InputAt(1)); |
| if (mtarget.HasValue() && mnewtarget.HasValue()) { |
| Handle<JSFunction> constructor = |
| Handle<JSFunction>::cast(mtarget.Value()); |
| if (constructor->has_initial_map()) { |
| Handle<Map> initial_map(constructor->initial_map(), isolate()); |
| if (initial_map->constructor_or_backpointer() == *mnewtarget.Value()) { |
| // Walk up the {effect} chain to see if the {receiver} is the |
| // dominating effect and there's no other observable write in |
| // between. |
| while (true) { |
| if (receiver == effect) return initial_map; |
| if (!effect->op()->HasProperty(Operator::kNoWrite) || |
| effect->op()->EffectInputCount() != 1) { |
| break; |
| } |
| effect = NodeProperties::GetEffectInput(effect); |
| } |
| } |
| } |
| } |
| } |
| return MaybeHandle<Map>(); |
| } |
| |
| MaybeHandle<Map> JSNativeContextSpecialization::InferReceiverRootMap( |
| Node* receiver) { |
| HeapObjectMatcher m(receiver); |
| if (m.HasValue()) { |
| return handle(m.Value()->map()->FindRootMap(), isolate()); |
| } else if (m.IsJSCreate()) { |
| HeapObjectMatcher mtarget(m.InputAt(0)); |
| HeapObjectMatcher mnewtarget(m.InputAt(1)); |
| if (mtarget.HasValue() && mnewtarget.HasValue()) { |
| Handle<JSFunction> constructor = |
| Handle<JSFunction>::cast(mtarget.Value()); |
| if (constructor->has_initial_map()) { |
| Handle<Map> initial_map(constructor->initial_map(), isolate()); |
| if (initial_map->constructor_or_backpointer() == *mnewtarget.Value()) { |
| DCHECK_EQ(*initial_map, initial_map->FindRootMap()); |
| return initial_map; |
| } |
| } |
| } |
| } |
| return MaybeHandle<Map>(); |
| } |
| |
| MaybeHandle<Context> JSNativeContextSpecialization::GetNativeContext( |
| Node* node) { |
| Node* const context = NodeProperties::GetContextInput(node); |
| return NodeProperties::GetSpecializationNativeContext(context, |
| native_context()); |
| } |
| |
| |
| Graph* JSNativeContextSpecialization::graph() const { |
| return jsgraph()->graph(); |
| } |
| |
| |
| Isolate* JSNativeContextSpecialization::isolate() const { |
| return jsgraph()->isolate(); |
| } |
| |
| |
| Factory* JSNativeContextSpecialization::factory() const { |
| return isolate()->factory(); |
| } |
| |
| |
| MachineOperatorBuilder* JSNativeContextSpecialization::machine() const { |
| return jsgraph()->machine(); |
| } |
| |
| |
| CommonOperatorBuilder* JSNativeContextSpecialization::common() const { |
| return jsgraph()->common(); |
| } |
| |
| |
| JSOperatorBuilder* JSNativeContextSpecialization::javascript() const { |
| return jsgraph()->javascript(); |
| } |
| |
| |
| SimplifiedOperatorBuilder* JSNativeContextSpecialization::simplified() const { |
| return jsgraph()->simplified(); |
| } |
| |
| } // namespace compiler |
| } // namespace internal |
| } // namespace v8 |