text: // Copyright 2014 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/code-stubs.h"
  #include "src/compiler/js-graph.h"
  #include "src/compiler/node-properties.h"
  #include "src/compiler/typer.h"
  
  namespace v8 {
  namespace internal {
  namespace compiler {
  
  Node* JSGraph::ImmovableHeapConstant(Handle<HeapObject> object) {
    Unique<HeapObject> unique = Unique<HeapObject>::CreateImmovable(object);
    return graph()->NewNode(common()->HeapConstant(unique));
  }
  
  
  #define CACHED(name, expr) \
    cached_nodes_[name] ? cached_nodes_[name] : (cached_nodes_[name] = (expr))
  
  
  Node* JSGraph::CEntryStubConstant(int result_size) {
    if (result_size == 1) {
      return CACHED(kCEntryStubConstant,
                    ImmovableHeapConstant(CEntryStub(isolate(), 1).GetCode()));
    }
    return ImmovableHeapConstant(CEntryStub(isolate(), result_size).GetCode());
  }
  
  
  Node* JSGraph::UndefinedConstant() {
    return CACHED(kUndefinedConstant,
                  ImmovableHeapConstant(factory()->undefined_value()));
  }
  
  
  Node* JSGraph::TheHoleConstant() {
    return CACHED(kTheHoleConstant,
                  ImmovableHeapConstant(factory()->the_hole_value()));
  }
  
  
  Node* JSGraph::TrueConstant() {
    return CACHED(kTrueConstant, ImmovableHeapConstant(factory()->true_value()));
  }
  
  
  Node* JSGraph::FalseConstant() {
    return CACHED(kFalseConstant,
                  ImmovableHeapConstant(factory()->false_value()));
  }
  
  
  Node* JSGraph::NullConstant() {
    return CACHED(kNullConstant, ImmovableHeapConstant(factory()->null_value()));
  }
  
  
  Node* JSGraph::ZeroConstant() {
    return CACHED(kZeroConstant, NumberConstant(0.0));
  }
  
  
  Node* JSGraph::OneConstant() {
    return CACHED(kOneConstant, NumberConstant(1.0));
  }
  
  
  Node* JSGraph::NaNConstant() {
    return CACHED(kNaNConstant,
                  NumberConstant(std::numeric_limits<double>::quiet_NaN()));
  }
  
  
  Node* JSGraph::HeapConstant(Unique<HeapObject> value) {
    // TODO(turbofan): canonicalize heap constants using Unique<T>
    return graph()->NewNode(common()->HeapConstant(value));
  }
  
  
  Node* JSGraph::HeapConstant(Handle<HeapObject> value) {
    // TODO(titzer): We could also match against the addresses of immortable
    // immovables here, even without access to the heap, thus always
    // canonicalizing references to them.
    // return HeapConstant(Unique<Object>::CreateUninitialized(value));
    // TODO(turbofan): This is a work-around to make Unique::HashCode() work for
    // value numbering. We need some sane way to compute a unique hash code for
    // arbitrary handles here.
    Unique<HeapObject> unique(reinterpret_cast<Address>(*value.location()),
                              value);
    return HeapConstant(unique);
  }
  
  
  Node* JSGraph::Constant(Handle<Object> value) {
    // Dereference the handle to determine if a number constant or other
    // canonicalized node can be used.
    if (value->IsNumber()) {
      return Constant(value->Number());
    } else if (value->IsUndefined()) {
      return UndefinedConstant();
    } else if (value->IsTrue()) {
      return TrueConstant();
    } else if (value->IsFalse()) {
      return FalseConstant();
    } else if (value->IsNull()) {
      return NullConstant();
    } else if (value->IsTheHole()) {
      return TheHoleConstant();
    } else {
      return HeapConstant(Handle<HeapObject>::cast(value));
    }
  }
  
  
  Node* JSGraph::Constant(double value) {
    if (bit_cast<int64_t>(value) == bit_cast<int64_t>(0.0)) return ZeroConstant();
    if (bit_cast<int64_t>(value) == bit_cast<int64_t>(1.0)) return OneConstant();
    return NumberConstant(value);
  }
  
  
  Node* JSGraph::Constant(int32_t value) {
    if (value == 0) return ZeroConstant();
    if (value == 1) return OneConstant();
    return NumberConstant(value);
  }
  
  
  Node* JSGraph::Int32Constant(int32_t value) {
    Node** loc = cache_.FindInt32Constant(value);
    if (*loc == NULL) {
      *loc = graph()->NewNode(common()->Int32Constant(value));
    }
    return *loc;
  }
  
  
  Node* JSGraph::Int64Constant(int64_t value) {
    Node** loc = cache_.FindInt64Constant(value);
    if (*loc == NULL) {
      *loc = graph()->NewNode(common()->Int64Constant(value));
    }
    return *loc;
  }
  
  
  Node* JSGraph::NumberConstant(double value) {
    Node** loc = cache_.FindNumberConstant(value);
    if (*loc == NULL) {
      *loc = graph()->NewNode(common()->NumberConstant(value));
    }
    return *loc;
  }
  
  
  Node* JSGraph::Float32Constant(float value) {
    Node** loc = cache_.FindFloat32Constant(value);
    if (*loc == NULL) {
      *loc = graph()->NewNode(common()->Float32Constant(value));
    }
    return *loc;
  }
  
  
  Node* JSGraph::Float64Constant(double value) {
    Node** loc = cache_.FindFloat64Constant(value);
    if (*loc == NULL) {
      *loc = graph()->NewNode(common()->Float64Constant(value));
    }
    return *loc;
  }
  
  
  Node* JSGraph::ExternalConstant(ExternalReference reference) {
    Node** loc = cache_.FindExternalConstant(reference);
    if (*loc == NULL) {
      *loc = graph()->NewNode(common()->ExternalConstant(reference));
    }
    return *loc;
  }
  
  
  Node* JSGraph::EmptyFrameState() {
    Node* empty_frame_state = cached_nodes_[kEmptyFrameState];
    if (!empty_frame_state || empty_frame_state->IsDead()) {
      Node* state_values = graph()->NewNode(common()->StateValues(0));
      empty_frame_state = graph()->NewNode(
          common()->FrameState(JS_FRAME, BailoutId::None(),
                               OutputFrameStateCombine::Ignore()),
          state_values, state_values, state_values, NoContextConstant(),
          UndefinedConstant());
      cached_nodes_[kEmptyFrameState] = empty_frame_state;
    }
    return empty_frame_state;
  }
  
  
  Node* JSGraph::DeadControl() {
    return CACHED(kDeadControl, graph()->NewNode(common()->Dead()));
  }
  
  
  void JSGraph::GetCachedNodes(NodeVector* nodes) {
    cache_.GetCachedNodes(nodes);
    for (size_t i = 0; i < arraysize(cached_nodes_); i++) {
      if (Node* node = cached_nodes_[i]) {
        if (!node->IsDead()) nodes->push_back(node);
      }
    }
  }
  
  }  // namespace compiler
  }  // namespace internal
  }  // namespace v8
  