| // 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/compiler/type-cache.h" |
| #include "src/field-index-inl.h" |
| #include "src/isolate-inl.h" |
| #include "src/type-feedback-vector.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace compiler { |
| |
| namespace { |
| |
| bool HasNumberMaps(MapList const& maps) { |
| for (auto map : maps) { |
| if (map->instance_type() == HEAP_NUMBER_TYPE) return true; |
| } |
| return false; |
| } |
| |
| bool HasOnlyJSArrayMaps(MapList const& maps) { |
| for (auto map : maps) { |
| if (!map->IsJSArrayMap()) return false; |
| } |
| return true; |
| } |
| |
| bool HasOnlyNumberMaps(MapList const& maps) { |
| for (auto map : maps) { |
| if (map->instance_type() != HEAP_NUMBER_TYPE) return false; |
| } |
| return true; |
| } |
| |
| template <typename T> |
| bool HasOnlyStringMaps(T const& maps) { |
| for (auto map : maps) { |
| if (!map->IsStringMap()) return false; |
| } |
| return true; |
| } |
| |
| } // namespace |
| |
| JSNativeContextSpecialization::JSNativeContextSpecialization( |
| Editor* editor, JSGraph* jsgraph, Flags flags, |
| Handle<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()); |
| // 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) { |
| 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* context = NodeProperties::GetContextInput(node); |
| Node* frame_state_eager = NodeProperties::FindFrameStateBefore(node); |
| Node* frame_state_lazy = NodeProperties::GetFrameStateInput(node); |
| Node* effect = NodeProperties::GetEffectInput(node); |
| Node* control = NodeProperties::GetControlInput(node); |
| |
| // Not much we can do if deoptimization support is disabled. |
| if (!(flags() & kDeoptimizationEnabled)) 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(); |
| } |
| |
| // TODO(turbofan): Add support for inlining into try blocks. |
| if (NodeProperties::IsExceptionalCall(node) || |
| !(flags() & kAccessorInliningEnabled)) { |
| for (auto access_info : access_infos) { |
| if (access_info.IsAccessorConstant()) return NoChange(); |
| } |
| } |
| |
| // Nothing to do if we have no non-deprecated maps. |
| if (access_infos.empty()) { |
| return ReduceSoftDeoptimize( |
| node, DeoptimizeReason::kInsufficientTypeFeedbackForGenericNamedAccess); |
| } |
| |
| // Ensure that {index} matches the specified {name} (if {index} is given). |
| if (index != nullptr) { |
| Node* check = graph()->NewNode(simplified()->ReferenceEqual(), index, |
| jsgraph()->HeapConstant(name)); |
| effect = graph()->NewNode(simplified()->CheckIf(), check, effect, control); |
| } |
| |
| // Check for the monomorphic cases. |
| if (access_infos.size() == 1) { |
| PropertyAccessInfo access_info = access_infos.front(); |
| if (HasOnlyStringMaps(access_info.receiver_maps())) { |
| // Monormorphic string access (ignoring the fact that there are multiple |
| // String maps). |
| receiver = effect = graph()->NewNode(simplified()->CheckString(), |
| receiver, effect, control); |
| } else if (HasOnlyNumberMaps(access_info.receiver_maps())) { |
| // Monomorphic number access (we also deal with Smis here). |
| receiver = effect = graph()->NewNode(simplified()->CheckNumber(), |
| receiver, effect, control); |
| } else { |
| // Monomorphic property access. |
| effect = BuildCheckHeapObject(receiver, effect, control); |
| effect = BuildCheckMaps(receiver, effect, control, |
| access_info.receiver_maps()); |
| } |
| |
| // Generate the actual property access. |
| ValueEffectControl continuation = |
| BuildPropertyAccess(receiver, value, context, frame_state_lazy, effect, |
| control, name, access_info, access_mode); |
| value = continuation.value(); |
| effect = continuation.effect(); |
| control = continuation.control(); |
| } else { |
| // 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()); |
| |
| // Check if {receiver} may be a number. |
| bool receiverissmi_possible = false; |
| for (PropertyAccessInfo const& access_info : access_infos) { |
| if (HasNumberMaps(access_info.receiver_maps())) { |
| 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 { |
| effect = BuildCheckHeapObject(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}. |
| MapList const& receiver_maps = access_info.receiver_maps(); |
| { |
| // Emit a (sequence of) map checks for other {receiver}s. |
| ZoneVector<Node*> this_controls(zone()); |
| ZoneVector<Node*> this_effects(zone()); |
| size_t num_classes = receiver_maps.size(); |
| for (auto map : receiver_maps) { |
| DCHECK_LT(0u, num_classes); |
| Node* check = |
| graph()->NewNode(simplified()->ReferenceEqual(), receiver_map, |
| jsgraph()->Constant(map)); |
| if (--num_classes == 0 && j == access_infos.size() - 1) { |
| check = graph()->NewNode(simplified()->CheckIf(), check, |
| this_effect, fallthrough_control); |
| this_controls.push_back(fallthrough_control); |
| this_effects.push_back(check); |
| 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 (HasNumberMaps(receiver_maps)) { |
| // 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 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 EffectPhi that is generated above. |
| this_effect = |
| graph()->NewNode(common()->Checkpoint(), frame_state_eager, |
| this_effect, this_control); |
| } |
| } |
| |
| // Generate the actual property access. |
| ValueEffectControl continuation = BuildPropertyAccess( |
| this_receiver, this_value, context, frame_state_lazy, this_effect, |
| this_control, name, access_info, access_mode); |
| values.push_back(continuation.value()); |
| effects.push_back(continuation.effect()); |
| controls.push_back(continuation.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::ReduceNamedAccessFromNexus( |
| 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, |
| DeoptimizeReason::kInsufficientTypeFeedbackForGenericNamedAccess); |
| } |
| 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, |
| DeoptimizeReason::kInsufficientTypeFeedbackForGenericNamedAccess); |
| } |
| 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 ReduceNamedAccessFromNexus(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 ReduceNamedAccessFromNexus(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* 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(); |
| |
| // Check for keyed access to strings. |
| if (HasOnlyStringMaps(receiver_maps)) { |
| // Strings are immutable in JavaScript. |
| if (access_mode == AccessMode::kStore) return NoChange(); |
| |
| // Ensure that the {receiver} is actually a String. |
| receiver = effect = graph()->NewNode(simplified()->CheckString(), receiver, |
| effect, control); |
| |
| // Determine the {receiver} length. |
| Node* length = effect = graph()->NewNode( |
| simplified()->LoadField(AccessBuilder::ForStringLength()), receiver, |
| effect, control); |
| |
| // Ensure that {index} is less than {receiver} length. |
| index = effect = graph()->NewNode(simplified()->CheckBounds(), index, |
| length, effect, control); |
| |
| // Load the character from the {receiver}. |
| value = graph()->NewNode(simplified()->StringCharCodeAt(), receiver, index, |
| control); |
| |
| // Return it as a single character string. |
| value = graph()->NewNode(simplified()->StringFromCharCode(), value); |
| } else { |
| // Retrieve the native context from the given {node}. |
| // 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 ReduceSoftDeoptimize( |
| node, |
| DeoptimizeReason::kInsufficientTypeFeedbackForGenericKeyedAccess); |
| } |
| |
| // For holey stores or growing stores, we need to check that the prototype |
| // chain contains no setters for elements, and we need to guard those checks |
| // via code dependencies on the relevant prototype maps. |
| if (access_mode == AccessMode::kStore) { |
| // TODO(turbofan): We could have a fast path here, that checks for the |
| // common case of Array or Object prototype only and therefore avoids |
| // the zone allocation of this vector. |
| ZoneVector<Handle<Map>> prototype_maps(zone()); |
| for (ElementAccessInfo const& access_info : access_infos) { |
| for (Handle<Map> receiver_map : access_info.receiver_maps()) { |
| // If the {receiver_map} has a prototype and it's elements backing |
| // store is either holey, or we have a potentially growing store, |
| // then we need to check that all prototypes have stable maps with |
| // fast elements (and we need to guard against changes to that below). |
| if (IsHoleyElementsKind(receiver_map->elements_kind()) || |
| IsGrowStoreMode(store_mode)) { |
| // Make sure all prototypes are stable and have fast elements. |
| for (Handle<Map> map = receiver_map;;) { |
| Handle<Object> map_prototype(map->prototype(), isolate()); |
| if (map_prototype->IsNull(isolate())) break; |
| if (!map_prototype->IsJSObject()) return NoChange(); |
| map = handle(Handle<JSObject>::cast(map_prototype)->map(), |
| isolate()); |
| if (!map->is_stable()) return NoChange(); |
| if (!IsFastElementsKind(map->elements_kind())) return NoChange(); |
| prototype_maps.push_back(map); |
| } |
| } |
| } |
| } |
| |
| // Install dependencies on the relevant prototype maps. |
| for (Handle<Map> prototype_map : prototype_maps) { |
| dependencies()->AssumeMapStable(prototype_map); |
| } |
| } |
| |
| // Ensure that {receiver} is a heap object. |
| effect = BuildCheckHeapObject(receiver, effect, control); |
| |
| // Check for the monomorphic case. |
| if (access_infos.size() == 1) { |
| ElementAccessInfo access_info = access_infos.front(); |
| |
| // Perform possible elements kind transitions. |
| for (auto transition : access_info.transitions()) { |
| Handle<Map> const transition_source = transition.first; |
| Handle<Map> const transition_target = transition.second; |
| effect = graph()->NewNode( |
| simplified()->TransitionElementsKind( |
| IsSimpleMapChangeTransition(transition_source->elements_kind(), |
| transition_target->elements_kind()) |
| ? ElementsTransition::kFastTransition |
| : ElementsTransition::kSlowTransition), |
| receiver, jsgraph()->HeapConstant(transition_source), |
| jsgraph()->HeapConstant(transition_target), effect, control); |
| } |
| |
| // 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. |
| effect = graph()->NewNode(common()->Checkpoint(), frame_state, effect, |
| control); |
| |
| // Perform map check on the {receiver}. |
| effect = BuildCheckMaps(receiver, effect, control, |
| access_info.receiver_maps()); |
| |
| // Access the actual element. |
| ValueEffectControl continuation = |
| BuildElementAccess(receiver, index, value, effect, control, |
| access_info, access_mode, store_mode); |
| value = continuation.value(); |
| effect = continuation.effect(); |
| control = continuation.control(); |
| } else { |
| // 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()); |
| |
| // 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 = effect; |
| Node* this_control = fallthrough_control; |
| |
| // Perform possible elements kind transitions. |
| for (auto transition : access_info.transitions()) { |
| Handle<Map> const transition_source = transition.first; |
| Handle<Map> const transition_target = transition.second; |
| this_effect = graph()->NewNode( |
| simplified()->TransitionElementsKind( |
| IsSimpleMapChangeTransition( |
| transition_source->elements_kind(), |
| transition_target->elements_kind()) |
| ? ElementsTransition::kFastTransition |
| : ElementsTransition::kSlowTransition), |
| receiver, jsgraph()->HeapConstant(transition_source), |
| jsgraph()->HeapConstant(transition_target), this_effect, |
| this_control); |
| } |
| |
| // Load the {receiver} map. |
| Node* receiver_map = this_effect = |
| graph()->NewNode(simplified()->LoadField(AccessBuilder::ForMap()), |
| receiver, this_effect, this_control); |
| |
| // Perform map check(s) on {receiver}. |
| MapList const& receiver_maps = access_info.receiver_maps(); |
| { |
| ZoneVector<Node*> this_controls(zone()); |
| ZoneVector<Node*> this_effects(zone()); |
| size_t num_classes = receiver_maps.size(); |
| for (Handle<Map> map : receiver_maps) { |
| DCHECK_LT(0u, num_classes); |
| Node* check = |
| graph()->NewNode(simplified()->ReferenceEqual(), receiver_map, |
| jsgraph()->Constant(map)); |
| if (--num_classes == 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. |
| check = graph()->NewNode(simplified()->CheckIf(), check, |
| this_effect, this_control); |
| this_controls.push_back(this_control); |
| this_effects.push_back(check); |
| 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); |
| } |
| } |
| |
| // 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 EffectPhi that is generated above. |
| this_effect = graph()->NewNode(common()->Checkpoint(), frame_state, |
| this_effect, this_control); |
| } |
| } |
| |
| // Access the actual element. |
| ValueEffectControl continuation = BuildElementAccess( |
| this_receiver, this_index, this_value, this_effect, this_control, |
| access_info, access_mode, store_mode); |
| values.push_back(continuation.value()); |
| effects.push_back(continuation.effect()); |
| controls.push_back(continuation.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); |
| } |
| |
| template <typename KeyedICNexus> |
| Reduction JSNativeContextSpecialization::ReduceKeyedAccess( |
| Node* node, Node* index, Node* value, KeyedICNexus 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, |
| DeoptimizeReason::kInsufficientTypeFeedbackForGenericKeyedAccess); |
| } |
| 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, |
| DeoptimizeReason::kInsufficientTypeFeedbackForGenericKeyedAccess); |
| } |
| 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); |
| } else if (nexus.GetKeyType() != ELEMENT) { |
| // The KeyedLoad/StoreIC has seen non-element accesses, so we cannot assume |
| // that the {index} is a valid array index, thus we just let the IC continue |
| // to deal with this load/store. |
| return NoChange(); |
| } |
| |
| // 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, DeoptimizeReason reason) { |
| Node* effect = NodeProperties::GetEffectInput(node); |
| Node* control = NodeProperties::GetControlInput(node); |
| Node* frame_state = NodeProperties::FindFrameStateBefore(node); |
| Node* deoptimize = |
| graph()->NewNode(common()->Deoptimize(DeoptimizeKind::kSoft, reason), |
| 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); |
| } |
| |
| JSNativeContextSpecialization::ValueEffectControl |
| JSNativeContextSpecialization::BuildPropertyAccess( |
| Node* receiver, Node* value, Node* context, Node* frame_state, Node* effect, |
| Node* control, Handle<Name> name, PropertyAccessInfo const& access_info, |
| AccessMode access_mode) { |
| // Determine actual holder and perform prototype chain checks. |
| Handle<JSObject> holder; |
| if (access_info.holder().ToHandle(&holder)) { |
| AssumePrototypesStable(access_info.receiver_maps(), holder); |
| } |
| |
| // Generate the actual property access. |
| if (access_info.IsNotFound()) { |
| DCHECK_EQ(AccessMode::kLoad, access_mode); |
| value = jsgraph()->UndefinedConstant(); |
| } else if (access_info.IsDataConstant()) { |
| value = jsgraph()->Constant(access_info.constant()); |
| if (access_mode == AccessMode::kStore) { |
| Node* check = |
| graph()->NewNode(simplified()->ReferenceEqual(), value, value); |
| effect = |
| graph()->NewNode(simplified()->CheckIf(), check, effect, control); |
| } |
| } else if (access_info.IsAccessorConstant()) { |
| // TODO(bmeurer): Properly rewire the IfException edge here if there's any. |
| Node* target = jsgraph()->Constant(access_info.constant()); |
| FrameStateInfo const& frame_info = OpParameter<FrameStateInfo>(frame_state); |
| Handle<SharedFunctionInfo> shared_info = |
| frame_info.shared_info().ToHandleChecked(); |
| switch (access_mode) { |
| case AccessMode::kLoad: { |
| // We need a FrameState for the getter stub to restore the correct |
| // context before returning to fullcodegen. |
| FrameStateFunctionInfo const* frame_info0 = |
| common()->CreateFrameStateFunctionInfo(FrameStateType::kGetterStub, |
| 1, 0, shared_info); |
| Node* frame_state0 = graph()->NewNode( |
| common()->FrameState(BailoutId::None(), |
| OutputFrameStateCombine::Ignore(), |
| frame_info0), |
| graph()->NewNode(common()->StateValues(1), receiver), |
| jsgraph()->EmptyStateValues(), jsgraph()->EmptyStateValues(), |
| context, target, frame_state); |
| |
| // Introduce the call to the getter function. |
| value = effect = graph()->NewNode( |
| javascript()->CallFunction( |
| 2, 0.0f, VectorSlotPair(), |
| ConvertReceiverMode::kNotNullOrUndefined), |
| target, receiver, context, frame_state0, effect, control); |
| control = graph()->NewNode(common()->IfSuccess(), value); |
| break; |
| } |
| case AccessMode::kStore: { |
| // We need a FrameState for the setter stub to restore the correct |
| // context and return the appropriate value to fullcodegen. |
| FrameStateFunctionInfo const* frame_info0 = |
| common()->CreateFrameStateFunctionInfo(FrameStateType::kSetterStub, |
| 2, 0, shared_info); |
| Node* frame_state0 = graph()->NewNode( |
| common()->FrameState(BailoutId::None(), |
| OutputFrameStateCombine::Ignore(), |
| frame_info0), |
| graph()->NewNode(common()->StateValues(2), receiver, value), |
| jsgraph()->EmptyStateValues(), jsgraph()->EmptyStateValues(), |
| context, target, frame_state); |
| |
| // Introduce the call to the setter function. |
| effect = graph()->NewNode(javascript()->CallFunction( |
| 3, 0.0f, VectorSlotPair(), |
| ConvertReceiverMode::kNotNullOrUndefined), |
| target, receiver, value, context, |
| frame_state0, effect, control); |
| control = graph()->NewNode(common()->IfSuccess(), effect); |
| break; |
| } |
| } |
| } else { |
| DCHECK(access_info.IsDataField()); |
| FieldIndex const field_index = access_info.field_index(); |
| Type* const field_type = access_info.field_type(); |
| MachineRepresentation const field_representation = |
| access_info.field_representation(); |
| if (access_mode == AccessMode::kLoad) { |
| if (access_info.holder().ToHandle(&holder)) { |
| receiver = jsgraph()->Constant(holder); |
| } |
| // Optimize immutable property loads. |
| HeapObjectMatcher m(receiver); |
| if (m.HasValue() && m.Value()->IsJSObject()) { |
| // TODO(turbofan): Given that we already have the field_index here, we |
| // might be smarter in the future and not rely on the LookupIterator, |
| // but for now let's just do what Crankshaft does. |
| LookupIterator it(m.Value(), name, |
| LookupIterator::OWN_SKIP_INTERCEPTOR); |
| if (it.IsFound() && it.IsReadOnly() && !it.IsConfigurable()) { |
| Node* value = jsgraph()->Constant(JSReceiver::GetDataProperty(&it)); |
| return ValueEffectControl(value, effect, control); |
| } |
| } |
| } |
| Node* storage = receiver; |
| if (!field_index.is_inobject()) { |
| storage = effect = graph()->NewNode( |
| simplified()->LoadField(AccessBuilder::ForJSObjectProperties()), |
| storage, effect, control); |
| } |
| FieldAccess field_access = { |
| kTaggedBase, |
| field_index.offset(), |
| name, |
| field_type, |
| MachineType::TypeForRepresentation(field_representation), |
| kFullWriteBarrier}; |
| if (access_mode == AccessMode::kLoad) { |
| if (field_representation == MachineRepresentation::kFloat64) { |
| if (!field_index.is_inobject() || field_index.is_hidden_field() || |
| !FLAG_unbox_double_fields) { |
| FieldAccess const storage_access = {kTaggedBase, |
| field_index.offset(), |
| name, |
| Type::OtherInternal(), |
| MachineType::TaggedPointer(), |
| kPointerWriteBarrier}; |
| storage = effect = |
| graph()->NewNode(simplified()->LoadField(storage_access), storage, |
| effect, control); |
| field_access.offset = HeapNumber::kValueOffset; |
| field_access.name = MaybeHandle<Name>(); |
| } |
| } |
| // TODO(turbofan): Track the field_map (if any) on the {field_access} and |
| // use it in LoadElimination to eliminate map checks. |
| value = effect = graph()->NewNode(simplified()->LoadField(field_access), |
| storage, effect, control); |
| } else { |
| DCHECK_EQ(AccessMode::kStore, access_mode); |
| switch (field_representation) { |
| case MachineRepresentation::kFloat64: { |
| value = effect = graph()->NewNode(simplified()->CheckNumber(), value, |
| effect, 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. |
| effect = graph()->NewNode( |
| common()->BeginRegion(RegionObservability::kNotObservable), |
| effect); |
| Node* box = effect = graph()->NewNode( |
| simplified()->Allocate(NOT_TENURED), |
| jsgraph()->Constant(HeapNumber::kSize), effect, control); |
| effect = graph()->NewNode( |
| simplified()->StoreField(AccessBuilder::ForMap()), box, |
| jsgraph()->HeapConstant(factory()->mutable_heap_number_map()), |
| effect, control); |
| effect = graph()->NewNode( |
| simplified()->StoreField(AccessBuilder::ForHeapNumberValue()), |
| box, value, effect, control); |
| value = effect = |
| graph()->NewNode(common()->FinishRegion(), box, effect); |
| |
| field_access.type = Type::Any(); |
| field_access.machine_type = MachineType::TaggedPointer(); |
| field_access.write_barrier_kind = kPointerWriteBarrier; |
| } else { |
| // We just store directly to the MutableHeapNumber. |
| FieldAccess const storage_access = {kTaggedBase, |
| field_index.offset(), |
| name, |
| Type::OtherInternal(), |
| MachineType::TaggedPointer(), |
| kPointerWriteBarrier}; |
| storage = effect = |
| graph()->NewNode(simplified()->LoadField(storage_access), |
| storage, effect, control); |
| field_access.offset = HeapNumber::kValueOffset; |
| field_access.name = MaybeHandle<Name>(); |
| field_access.machine_type = MachineType::Float64(); |
| } |
| } |
| break; |
| } |
| case MachineRepresentation::kTaggedSigned: { |
| value = effect = graph()->NewNode(simplified()->CheckSmi(), value, |
| effect, control); |
| field_access.write_barrier_kind = kNoWriteBarrier; |
| break; |
| } |
| case MachineRepresentation::kTaggedPointer: { |
| // Ensure that {value} is a HeapObject. |
| value = effect = graph()->NewNode(simplified()->CheckHeapObject(), |
| value, effect, control); |
| Handle<Map> field_map; |
| if (access_info.field_map().ToHandle(&field_map)) { |
| // Emit a map check for the value. |
| effect = graph()->NewNode(simplified()->CheckMaps(1), value, |
| jsgraph()->HeapConstant(field_map), |
| effect, control); |
| } |
| field_access.write_barrier_kind = kPointerWriteBarrier; |
| break; |
| } |
| case MachineRepresentation::kTagged: |
| break; |
| case MachineRepresentation::kNone: |
| case MachineRepresentation::kBit: |
| case MachineRepresentation::kWord8: |
| case MachineRepresentation::kWord16: |
| case MachineRepresentation::kWord32: |
| case MachineRepresentation::kWord64: |
| case MachineRepresentation::kFloat32: |
| case MachineRepresentation::kSimd128: |
| UNREACHABLE(); |
| break; |
| } |
| Handle<Map> transition_map; |
| if (access_info.transition_map().ToHandle(&transition_map)) { |
| effect = graph()->NewNode( |
| common()->BeginRegion(RegionObservability::kObservable), effect); |
| effect = graph()->NewNode( |
| simplified()->StoreField(AccessBuilder::ForMap()), receiver, |
| jsgraph()->Constant(transition_map), effect, control); |
| } |
| effect = graph()->NewNode(simplified()->StoreField(field_access), storage, |
| value, effect, control); |
| if (access_info.HasTransitionMap()) { |
| effect = graph()->NewNode(common()->FinishRegion(), |
| jsgraph()->UndefinedConstant(), effect); |
| } |
| } |
| } |
| |
| return ValueEffectControl(value, effect, control); |
| } |
| |
| namespace { |
| |
| ExternalArrayType GetArrayTypeFromElementsKind(ElementsKind kind) { |
| switch (kind) { |
| #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) \ |
| case TYPE##_ELEMENTS: \ |
| return kExternal##Type##Array; |
| TYPED_ARRAYS(TYPED_ARRAY_CASE) |
| #undef TYPED_ARRAY_CASE |
| default: |
| break; |
| } |
| UNREACHABLE(); |
| return kExternalInt8Array; |
| } |
| |
| } // namespace |
| |
| JSNativeContextSpecialization::ValueEffectControl |
| JSNativeContextSpecialization::BuildElementAccess( |
| Node* receiver, Node* index, Node* value, Node* effect, Node* control, |
| ElementAccessInfo const& access_info, AccessMode access_mode, |
| KeyedAccessStoreMode store_mode) { |
| // 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(); |
| MapList const& receiver_maps = access_info.receiver_maps(); |
| |
| // Load the elements for the {receiver}. |
| Node* elements = effect = graph()->NewNode( |
| simplified()->LoadField(AccessBuilder::ForJSObjectElements()), receiver, |
| effect, control); |
| |
| // Don't try to store to a copy-on-write backing store. |
| if (access_mode == AccessMode::kStore && |
| IsFastSmiOrObjectElementsKind(elements_kind) && |
| store_mode != STORE_NO_TRANSITION_HANDLE_COW) { |
| effect = |
| graph()->NewNode(simplified()->CheckMaps(1), elements, |
| jsgraph()->FixedArrayMapConstant(), effect, control); |
| } |
| |
| if (IsFixedTypedArrayElementsKind(elements_kind)) { |
| // Load the {receiver}s length. |
| Node* length = effect = graph()->NewNode( |
| simplified()->LoadField(AccessBuilder::ForJSTypedArrayLength()), |
| receiver, effect, control); |
| |
| // Check if the {receiver}s buffer was neutered. |
| Node* buffer = effect = graph()->NewNode( |
| simplified()->LoadField(AccessBuilder::ForJSArrayBufferViewBuffer()), |
| receiver, effect, control); |
| Node* check = effect = graph()->NewNode( |
| simplified()->ArrayBufferWasNeutered(), buffer, effect, control); |
| |
| // Default to zero if the {receiver}s buffer was neutered. |
| length = graph()->NewNode( |
| common()->Select(MachineRepresentation::kTagged, BranchHint::kFalse), |
| check, jsgraph()->ZeroConstant(), length); |
| |
| if (store_mode == STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) { |
| // Check that the {index} is a valid array index, we do the actual |
| // bounds check below and just skip the store below if it's out of |
| // bounds for the {receiver}. |
| index = effect = graph()->NewNode(simplified()->CheckBounds(), index, |
| jsgraph()->Constant(Smi::kMaxValue), |
| effect, control); |
| } else { |
| // Check that the {index} is in the valid range for the {receiver}. |
| DCHECK_EQ(STANDARD_STORE, store_mode); |
| index = effect = graph()->NewNode(simplified()->CheckBounds(), index, |
| length, effect, control); |
| } |
| |
| // Load the base and external pointer for the {receiver}. |
| Node* base_pointer = effect = graph()->NewNode( |
| simplified()->LoadField( |
| AccessBuilder::ForFixedTypedArrayBaseBasePointer()), |
| elements, effect, control); |
| Node* external_pointer = effect = graph()->NewNode( |
| simplified()->LoadField( |
| AccessBuilder::ForFixedTypedArrayBaseExternalPointer()), |
| elements, effect, control); |
| |
| // Access the actual element. |
| ExternalArrayType external_array_type = |
| GetArrayTypeFromElementsKind(elements_kind); |
| switch (access_mode) { |
| case AccessMode::kLoad: { |
| value = effect = graph()->NewNode( |
| simplified()->LoadTypedElement(external_array_type), buffer, |
| base_pointer, external_pointer, index, effect, control); |
| break; |
| } |
| case AccessMode::kStore: { |
| // Ensure that the {value} is actually a Number. |
| value = effect = graph()->NewNode(simplified()->CheckNumber(), value, |
| effect, control); |
| |
| // Check if we can skip the out-of-bounds store. |
| if (store_mode == STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) { |
| Node* check = |
| graph()->NewNode(simplified()->NumberLessThan(), index, length); |
| Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue), |
| check, control); |
| |
| Node* if_true = graph()->NewNode(common()->IfTrue(), branch); |
| Node* etrue = effect; |
| { |
| // Perform the actual store. |
| etrue = graph()->NewNode( |
| simplified()->StoreTypedElement(external_array_type), buffer, |
| base_pointer, external_pointer, index, value, etrue, if_true); |
| } |
| |
| Node* if_false = graph()->NewNode(common()->IfFalse(), branch); |
| Node* efalse = effect; |
| { |
| // Just ignore the out-of-bounds write. |
| } |
| |
| control = graph()->NewNode(common()->Merge(2), if_true, if_false); |
| effect = |
| graph()->NewNode(common()->EffectPhi(2), etrue, efalse, control); |
| } else { |
| // Perform the actual store |
| DCHECK_EQ(STANDARD_STORE, store_mode); |
| effect = graph()->NewNode( |
| simplified()->StoreTypedElement(external_array_type), buffer, |
| base_pointer, external_pointer, index, value, effect, control); |
| } |
| break; |
| } |
| } |
| } else { |
| // Check if the {receiver} is a JSArray. |
| bool receiver_is_jsarray = HasOnlyJSArrayMaps(receiver_maps); |
| |
| // Load the length of the {receiver}. |
| Node* length = effect = |
| receiver_is_jsarray |
| ? graph()->NewNode( |
| simplified()->LoadField( |
| AccessBuilder::ForJSArrayLength(elements_kind)), |
| receiver, effect, control) |
| : graph()->NewNode( |
| simplified()->LoadField(AccessBuilder::ForFixedArrayLength()), |
| elements, effect, control); |
| |
| // Check if we might need to grow the {elements} backing store. |
| if (IsGrowStoreMode(store_mode)) { |
| DCHECK_EQ(AccessMode::kStore, access_mode); |
| |
| // Check that the {index} is a valid array index; the actual checking |
| // happens below right before the element store. |
| index = effect = graph()->NewNode(simplified()->CheckBounds(), index, |
| jsgraph()->Constant(Smi::kMaxValue), |
| effect, control); |
| } else { |
| // Check that the {index} is in the valid range for the {receiver}. |
| index = effect = graph()->NewNode(simplified()->CheckBounds(), index, |
| length, effect, control); |
| } |
| |
| // Compute the element access. |
| Type* element_type = Type::NonInternal(); |
| 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; |
| element_machine_type = MachineType::TaggedSigned(); |
| } |
| ElementAccess element_access = {kTaggedBase, FixedArray::kHeaderSize, |
| element_type, element_machine_type, |
| kFullWriteBarrier}; |
| |
| // Access the actual element. |
| 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::Hole(), graph()->zone()); |
| element_access.machine_type = MachineType::AnyTagged(); |
| } |
| // Perform the actual backing store access. |
| value = effect = |
| graph()->NewNode(simplified()->LoadElement(element_access), elements, |
| index, effect, 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) { |
| // Check if we are allowed to turn the hole into undefined. |
| if (CanTreatHoleAsUndefined(receiver_maps)) { |
| // Turn the hole into undefined. |
| value = graph()->NewNode(simplified()->ConvertTaggedHoleToUndefined(), |
| value); |
| } else { |
| // Bailout if we see the hole. |
| value = effect = graph()->NewNode(simplified()->CheckTaggedHole(), |
| value, effect, 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. |
| if (CanTreatHoleAsUndefined(receiver_maps)) { |
| // Return the signaling NaN hole directly if all uses are truncating. |
| mode = CheckFloat64HoleMode::kAllowReturnHole; |
| } |
| value = effect = graph()->NewNode(simplified()->CheckFloat64Hole(mode), |
| value, effect, control); |
| } |
| } else { |
| DCHECK_EQ(AccessMode::kStore, access_mode); |
| if (IsFastSmiElementsKind(elements_kind)) { |
| value = effect = |
| graph()->NewNode(simplified()->CheckSmi(), value, effect, control); |
| } else if (IsFastDoubleElementsKind(elements_kind)) { |
| value = effect = graph()->NewNode(simplified()->CheckNumber(), value, |
| effect, control); |
| // Make sure we do not store signalling NaNs into double arrays. |
| value = graph()->NewNode(simplified()->NumberSilenceNaN(), value); |
| } |
| |
| // Ensure that copy-on-write backing store is writable. |
| if (IsFastSmiOrObjectElementsKind(elements_kind) && |
| store_mode == STORE_NO_TRANSITION_HANDLE_COW) { |
| elements = effect = |
| graph()->NewNode(simplified()->EnsureWritableFastElements(), |
| receiver, elements, effect, control); |
| } else if (IsGrowStoreMode(store_mode)) { |
| // Grow {elements} backing store if necessary. Also updates the |
| // "length" property for JSArray {receiver}s, hence there must |
| // not be any other check after this operation, as the write |
| // to the "length" property is observable. |
| GrowFastElementsFlags flags = GrowFastElementsFlag::kNone; |
| if (receiver_is_jsarray) { |
| flags |= GrowFastElementsFlag::kArrayObject; |
| } |
| if (IsHoleyElementsKind(elements_kind)) { |
| flags |= GrowFastElementsFlag::kHoleyElements; |
| } |
| if (IsFastDoubleElementsKind(elements_kind)) { |
| flags |= GrowFastElementsFlag::kDoubleElements; |
| } |
| elements = effect = graph()->NewNode( |
| simplified()->MaybeGrowFastElements(flags), receiver, elements, |
| index, length, effect, control); |
| } |
| |
| // Perform the actual element access. |
| effect = graph()->NewNode(simplified()->StoreElement(element_access), |
| elements, index, value, effect, control); |
| } |
| } |
| |
| return ValueEffectControl(value, effect, control); |
| } |
| |
| Node* JSNativeContextSpecialization::BuildCheckMaps( |
| Node* receiver, Node* effect, Node* control, |
| std::vector<Handle<Map>> const& maps) { |
| HeapObjectMatcher m(receiver); |
| if (m.HasValue()) { |
| Handle<Map> receiver_map(m.Value()->map(), isolate()); |
| if (receiver_map->is_stable()) { |
| for (Handle<Map> map : maps) { |
| if (map.is_identical_to(receiver_map)) { |
| dependencies()->AssumeMapStable(receiver_map); |
| return effect; |
| } |
| } |
| } |
| } |
| int const map_input_count = static_cast<int>(maps.size()); |
| int const input_count = 1 + map_input_count + 1 + 1; |
| Node** inputs = zone()->NewArray<Node*>(input_count); |
| inputs[0] = receiver; |
| for (int i = 0; i < map_input_count; ++i) { |
| inputs[1 + i] = jsgraph()->HeapConstant(maps[i]); |
| } |
| inputs[input_count - 2] = effect; |
| inputs[input_count - 1] = control; |
| return graph()->NewNode(simplified()->CheckMaps(map_input_count), input_count, |
| inputs); |
| } |
| |
| Node* JSNativeContextSpecialization::BuildCheckHeapObject(Node* receiver, |
| Node* effect, |
| Node* control) { |
| switch (receiver->opcode()) { |
| case IrOpcode::kHeapConstant: |
| case IrOpcode::kJSCreate: |
| case IrOpcode::kJSCreateArguments: |
| case IrOpcode::kJSCreateArray: |
| case IrOpcode::kJSCreateClosure: |
| case IrOpcode::kJSCreateIterResultObject: |
| case IrOpcode::kJSCreateLiteralArray: |
| case IrOpcode::kJSCreateLiteralObject: |
| case IrOpcode::kJSCreateLiteralRegExp: |
| case IrOpcode::kJSConvertReceiver: |
| case IrOpcode::kJSToName: |
| case IrOpcode::kJSToString: |
| case IrOpcode::kJSToObject: |
| case IrOpcode::kJSTypeOf: { |
| return effect; |
| } |
| default: { |
| return graph()->NewNode(simplified()->CheckHeapObject(), receiver, effect, |
| control); |
| } |
| } |
| } |
| |
| void JSNativeContextSpecialization::AssumePrototypesStable( |
| std::vector<Handle<Map>> const& receiver_maps, Handle<JSObject> holder) { |
| // Determine actual holder and perform prototype chain checks. |
| for (auto map : receiver_maps) { |
| // 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::CanTreatHoleAsUndefined( |
| std::vector<Handle<Map>> const& receiver_maps) { |
| // Check if the array prototype chain is intact. |
| if (!isolate()->IsFastArrayConstructorPrototypeChainIntact()) return false; |
| |
| // Make sure both the initial Array and Object prototypes are stable. |
| Handle<JSObject> initial_array_prototype( |
| native_context()->initial_array_prototype(), isolate()); |
| Handle<JSObject> initial_object_prototype( |
| native_context()->initial_object_prototype(), isolate()); |
| if (!initial_array_prototype->map()->is_stable() || |
| !initial_object_prototype->map()->is_stable()) { |
| return false; |
| } |
| |
| // Check if all {receiver_maps} either have the initial Array.prototype |
| // or the initial Object.prototype as their prototype, as those are |
| // guarded by the array protector cell. |
| for (Handle<Map> map : receiver_maps) { |
| if (map->prototype() != *initial_array_prototype && |
| map->prototype() != *initial_object_prototype) { |
| return false; |
| } |
| } |
| |
| // Install code dependencies on the prototype maps. |
| for (Handle<Map> map : receiver_maps) { |
| dependencies()->AssumePrototypeMapsStable(map, initial_object_prototype); |
| } |
| |
| // Install code dependency on the array protector cell. |
| dependencies()->AssumePropertyCell(factory()->array_protector()); |
| return true; |
| } |
| |
| 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) { |
| HeapObjectMatcher m(receiver); |
| if (m.HasValue()) { |
| Handle<Map> receiver_map(m.Value()->map(), isolate()); |
| if (receiver_map->is_stable()) return receiver_map; |
| } 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()) { |
| // 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); |
| } |
| } |
| } |
| } |
| } |
| // TODO(turbofan): Go hunting for CheckMaps(receiver) in the effect chain? |
| 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>(); |
| } |
| |
| 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 |
