allocation-builder.h

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// Copyright 2017 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.
 
#ifndef V8_COMPILER_ALLOCATION_BUILDER_H_
#define V8_COMPILER_ALLOCATION_BUILDER_H_
 
#include "src/compiler/js-graph.h"
#include "src/compiler/node.h"
#include "src/compiler/simplified-operator.h"
 
namespace v8 {
namespace internal {
namespace compiler {
 
// A helper class to construct inline allocations on the simplified operator
// level. This keeps track of the effect chain for initial stores on a newly
// allocated object and also provides helpers for commonly allocated objects.
class AllocationBuilder final {
 public:
  AllocationBuilder(JSGraph* jsgraph, JSHeapBroker* broker, Node* effect,
                    Node* control)
      : jsgraph_(jsgraph),
        broker_(broker),
        allocation_(nullptr),
        effect_(effect),
        control_(control) {}
 
  // Primitive allocation of static size.
  inline void Allocate(int size,
                       AllocationType allocation = AllocationType::kYoung,
                       Type type = Type::Any());
 
  // Primitive store into a field.
  void Store(const FieldAccess& access, Node* value) {
    effect_ = graph()->NewNode(simplified()->StoreField(access), allocation_,
                               value, effect_, control_);
  }
 
  // Primitive store into an element.
  void Store(ElementAccess const& access, Node* index, Node* value) {
    effect_ = graph()->NewNode(simplified()->StoreElement(access), allocation_,
                               index, value, effect_, control_);
  }
 
  // Compound allocation of a context.
  inline void AllocateContext(int variadic_part_length, MapRef map);
 
  // Compound allocation of a FixedArray.
  inline bool CanAllocateArray(
      int length, MapRef map,
      AllocationType allocation = AllocationType::kYoung);
  inline void AllocateArray(int length, MapRef map,
                            AllocationType allocation = AllocationType::kYoung);
 
  // Compound allocation of a SloppyArgumentsElements
  inline bool CanAllocateSloppyArgumentElements(
      int length, MapRef map,
      AllocationType allocation = AllocationType::kYoung);
  inline void AllocateSloppyArgumentElements(
      int length, MapRef map,
      AllocationType allocation = AllocationType::kYoung);
 
  // Compound store of a constant into a field.
  void Store(const FieldAccess& access, ObjectRef value) {
    if (access.machine_type == MachineType::IndirectPointer()) {
      Store(access,
            jsgraph()->TrustedHeapConstant(value.AsHeapObject().object()));
    } else {
      Store(access, jsgraph()->ConstantNoHole(value, broker_));
    }
  }
 
  void FinishAndChange(Node* node) {
    NodeProperties::SetType(allocation_, NodeProperties::GetType(node));
    node->ReplaceInput(0, allocation_);
    node->ReplaceInput(1, effect_);
    node->TrimInputCount(2);
    NodeProperties::ChangeOp(node, common()->FinishRegion());
  }
 
  Node* Finish() {
    return graph()->NewNode(common()->FinishRegion(), allocation_, effect_);
  }
 
 protected:
  JSGraph* jsgraph() { return jsgraph_; }
  Isolate* isolate() const { return jsgraph_->isolate(); }
  TFGraph* graph() { return jsgraph_->graph(); }
  CommonOperatorBuilder* common() { return jsgraph_->common(); }
  SimplifiedOperatorBuilder* simplified() { return jsgraph_->simplified(); }
 
 private:
  JSGraph* const jsgraph_;
  JSHeapBroker* const broker_;
  Node* allocation_;
  Node* effect_;
  Node* control_;
};
 
}  // namespace compiler
}  // namespace internal
}  // namespace v8
 
#endif  // V8_COMPILER_ALLOCATION_BUILDER_H_