// 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-intrinsic-lowering.h"

#include <stack>

#include "src/code-factory.h"
#include "src/compiler/access-builder.h"
#include "src/compiler/js-graph.h"
#include "src/compiler/linkage.h"
#include "src/compiler/node-matchers.h"
#include "src/compiler/node-properties.h"
#include "src/compiler/operator-properties.h"
#include "src/counters.h"
#include "src/objects-inl.h"
#include "src/objects/js-generator.h"

namespace v8 {
namespace internal {
namespace compiler {

JSIntrinsicLowering::JSIntrinsicLowering(Editor* editor, JSGraph* jsgraph)
    : AdvancedReducer(editor), jsgraph_(jsgraph) {}

Reduction JSIntrinsicLowering::Reduce(Node* node) {
  if (node->opcode() != IrOpcode::kJSCallRuntime) return NoChange();
  const Runtime::Function* const f =
      Runtime::FunctionForId(CallRuntimeParametersOf(node->op()).id());
  if (f->intrinsic_type != Runtime::IntrinsicType::INLINE) return NoChange();
  switch (f->function_id) {
    case Runtime::kInlineCreateIterResultObject:
      return ReduceCreateIterResultObject(node);
    case Runtime::kInlineDeoptimizeNow:
      return ReduceDeoptimizeNow(node);
    case Runtime::kInlineGeneratorClose:
      return ReduceGeneratorClose(node);
    case Runtime::kInlineCreateJSGeneratorObject:
      return ReduceCreateJSGeneratorObject(node);
    case Runtime::kInlineAsyncGeneratorReject:
      return ReduceAsyncGeneratorReject(node);
    case Runtime::kInlineAsyncGeneratorResolve:
      return ReduceAsyncGeneratorResolve(node);
    case Runtime::kInlineAsyncGeneratorYield:
      return ReduceAsyncGeneratorYield(node);
    case Runtime::kInlineGeneratorGetResumeMode:
      return ReduceGeneratorGetResumeMode(node);
    case Runtime::kInlineIsArray:
      return ReduceIsInstanceType(node, JS_ARRAY_TYPE);
    case Runtime::kInlineIsTypedArray:
      return ReduceIsInstanceType(node, JS_TYPED_ARRAY_TYPE);
    case Runtime::kInlineIsJSReceiver:
      return ReduceIsJSReceiver(node);
    case Runtime::kInlineIsSmi:
      return ReduceIsSmi(node);
    case Runtime::kInlineRejectPromise:
      return ReduceRejectPromise(node);
    case Runtime::kInlineResolvePromise:
      return ReduceResolvePromise(node);
    case Runtime::kInlineToLength:
      return ReduceToLength(node);
    case Runtime::kInlineToObject:
      return ReduceToObject(node);
    case Runtime::kInlineToString:
      return ReduceToString(node);
    case Runtime::kInlineCall:
      return ReduceCall(node);
    default:
      break;
  }
  return NoChange();
}


Reduction JSIntrinsicLowering::ReduceCreateIterResultObject(Node* node) {
  Node* const value = NodeProperties::GetValueInput(node, 0);
  Node* const done = NodeProperties::GetValueInput(node, 1);
  Node* const context = NodeProperties::GetContextInput(node);
  Node* const effect = NodeProperties::GetEffectInput(node);
  return Change(node, javascript()->CreateIterResultObject(), value, done,
                context, effect);
}

Reduction JSIntrinsicLowering::ReduceDeoptimizeNow(Node* node) {
  Node* const frame_state = NodeProperties::GetFrameStateInput(node);
  Node* const effect = NodeProperties::GetEffectInput(node);
  Node* const control = NodeProperties::GetControlInput(node);

  // TODO(bmeurer): Move MergeControlToEnd() to the AdvancedReducer.
  Node* deoptimize = graph()->NewNode(
      common()->Deoptimize(DeoptimizeKind::kEager,
                           DeoptimizeReason::kDeoptimizeNow, VectorSlotPair()),
      frame_state, effect, control);
  NodeProperties::MergeControlToEnd(graph(), common(), deoptimize);
  Revisit(graph()->end());

  node->TrimInputCount(0);
  NodeProperties::ChangeOp(node, common()->Dead());
  return Changed(node);
}

Reduction JSIntrinsicLowering::ReduceCreateJSGeneratorObject(Node* node) {
  Node* const closure = NodeProperties::GetValueInput(node, 0);
  Node* const receiver = NodeProperties::GetValueInput(node, 1);
  Node* const context = NodeProperties::GetContextInput(node);
  Node* const effect = NodeProperties::GetEffectInput(node);
  Node* const control = NodeProperties::GetControlInput(node);
  Operator const* const op = javascript()->CreateGeneratorObject();
  Node* create_generator =
      graph()->NewNode(op, closure, receiver, context, effect, control);
  ReplaceWithValue(node, create_generator, create_generator);
  return Changed(create_generator);
}

Reduction JSIntrinsicLowering::ReduceGeneratorClose(Node* node) {
  Node* const generator = NodeProperties::GetValueInput(node, 0);
  Node* const effect = NodeProperties::GetEffectInput(node);
  Node* const control = NodeProperties::GetControlInput(node);
  Node* const closed = jsgraph()->Constant(JSGeneratorObject::kGeneratorClosed);
  Node* const undefined = jsgraph()->UndefinedConstant();
  Operator const* const op = simplified()->StoreField(
      AccessBuilder::ForJSGeneratorObjectContinuation());

  ReplaceWithValue(node, undefined, node);
  NodeProperties::RemoveType(node);
  return Change(node, op, generator, closed, effect, control);
}

Reduction JSIntrinsicLowering::ReduceAsyncGeneratorReject(Node* node) {
  return Change(
      node, Builtins::CallableFor(isolate(), Builtins::kAsyncGeneratorReject),
      0);
}

Reduction JSIntrinsicLowering::ReduceAsyncGeneratorResolve(Node* node) {
  return Change(
      node, Builtins::CallableFor(isolate(), Builtins::kAsyncGeneratorResolve),
      0);
}

Reduction JSIntrinsicLowering::ReduceAsyncGeneratorYield(Node* node) {
  return Change(
      node, Builtins::CallableFor(isolate(), Builtins::kAsyncGeneratorYield),
      0);
}

Reduction JSIntrinsicLowering::ReduceGeneratorGetResumeMode(Node* node) {
  Node* const generator = NodeProperties::GetValueInput(node, 0);
  Node* const effect = NodeProperties::GetEffectInput(node);
  Node* const control = NodeProperties::GetControlInput(node);
  Operator const* const op =
      simplified()->LoadField(AccessBuilder::ForJSGeneratorObjectResumeMode());

  return Change(node, op, generator, effect, control);
}

Reduction JSIntrinsicLowering::ReduceIsInstanceType(
    Node* node, InstanceType instance_type) {
  // if (%_IsSmi(value)) {
  //   return false;
  // } else {
  //   return %_GetInstanceType(%_GetMap(value)) == instance_type;
  // }
  Node* value = NodeProperties::GetValueInput(node, 0);
  Node* effect = NodeProperties::GetEffectInput(node);
  Node* control = NodeProperties::GetControlInput(node);

  Node* check = graph()->NewNode(simplified()->ObjectIsSmi(), value);
  Node* branch = graph()->NewNode(common()->Branch(), check, control);

  Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
  Node* etrue = effect;
  Node* vtrue = jsgraph()->FalseConstant();

  Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
  Node* efalse = effect;
  Node* map = efalse =
      graph()->NewNode(simplified()->LoadField(AccessBuilder::ForMap()), value,
                       efalse, if_false);
  Node* map_instance_type = efalse = graph()->NewNode(
      simplified()->LoadField(AccessBuilder::ForMapInstanceType()), map, efalse,
      if_false);
  Node* vfalse =
      graph()->NewNode(simplified()->NumberEqual(), map_instance_type,
                       jsgraph()->Constant(instance_type));

  Node* merge = graph()->NewNode(common()->Merge(2), if_true, if_false);

  // Replace all effect uses of {node} with the {ephi}.
  Node* ephi = graph()->NewNode(common()->EffectPhi(2), etrue, efalse, merge);
  ReplaceWithValue(node, node, ephi, merge);

  // Turn the {node} into a Phi.
  return Change(node, common()->Phi(MachineRepresentation::kTagged, 2), vtrue,
                vfalse, merge);
}


Reduction JSIntrinsicLowering::ReduceIsJSReceiver(Node* node) {
  return Change(node, simplified()->ObjectIsReceiver());
}


Reduction JSIntrinsicLowering::ReduceIsSmi(Node* node) {
  return Change(node, simplified()->ObjectIsSmi());
}

Reduction JSIntrinsicLowering::ReduceRejectPromise(Node* node) {
  RelaxControls(node);
  NodeProperties::ChangeOp(node, javascript()->RejectPromise());
  return Changed(node);
}

Reduction JSIntrinsicLowering::ReduceResolvePromise(Node* node) {
  RelaxControls(node);
  NodeProperties::ChangeOp(node, javascript()->ResolvePromise());
  return Changed(node);
}

Reduction JSIntrinsicLowering::Change(Node* node, const Operator* op) {
  // Replace all effect uses of {node} with the effect dependency.
  RelaxEffectsAndControls(node);
  // Remove the inputs corresponding to context, effect and control.
  NodeProperties::RemoveNonValueInputs(node);
  // Finally update the operator to the new one.
  NodeProperties::ChangeOp(node, op);
  return Changed(node);
}


Reduction JSIntrinsicLowering::ReduceToLength(Node* node) {
  NodeProperties::ChangeOp(node, javascript()->ToLength());
  return Changed(node);
}


Reduction JSIntrinsicLowering::ReduceToObject(Node* node) {
  NodeProperties::ChangeOp(node, javascript()->ToObject());
  return Changed(node);
}


Reduction JSIntrinsicLowering::ReduceToString(Node* node) {
  // ToString is unnecessary if the input is a string.
  HeapObjectMatcher m(NodeProperties::GetValueInput(node, 0));
  if (m.HasValue() && m.Value()->IsString()) {
    ReplaceWithValue(node, m.node());
    return Replace(m.node());
  }
  NodeProperties::ChangeOp(node, javascript()->ToString());
  return Changed(node);
}


Reduction JSIntrinsicLowering::ReduceCall(Node* node) {
  size_t const arity = CallRuntimeParametersOf(node->op()).arity();
  NodeProperties::ChangeOp(node, javascript()->Call(arity));
  return Changed(node);
}

Reduction JSIntrinsicLowering::Change(Node* node, const Operator* op, Node* a,
                                      Node* b) {
  RelaxControls(node);
  node->ReplaceInput(0, a);
  node->ReplaceInput(1, b);
  node->TrimInputCount(2);
  NodeProperties::ChangeOp(node, op);
  return Changed(node);
}


Reduction JSIntrinsicLowering::Change(Node* node, const Operator* op, Node* a,
                                      Node* b, Node* c) {
  RelaxControls(node);
  node->ReplaceInput(0, a);
  node->ReplaceInput(1, b);
  node->ReplaceInput(2, c);
  node->TrimInputCount(3);
  NodeProperties::ChangeOp(node, op);
  return Changed(node);
}


Reduction JSIntrinsicLowering::Change(Node* node, const Operator* op, Node* a,
                                      Node* b, Node* c, Node* d) {
  RelaxControls(node);
  node->ReplaceInput(0, a);
  node->ReplaceInput(1, b);
  node->ReplaceInput(2, c);
  node->ReplaceInput(3, d);
  node->TrimInputCount(4);
  NodeProperties::ChangeOp(node, op);
  return Changed(node);
}


Reduction JSIntrinsicLowering::Change(Node* node, Callable const& callable,
                                      int stack_parameter_count) {
  auto call_descriptor = Linkage::GetStubCallDescriptor(
      graph()->zone(), callable.descriptor(), stack_parameter_count,
      CallDescriptor::kNeedsFrameState, node->op()->properties());
  node->InsertInput(graph()->zone(), 0,
                    jsgraph()->HeapConstant(callable.code()));
  NodeProperties::ChangeOp(node, common()->Call(call_descriptor));
  return Changed(node);
}


Graph* JSIntrinsicLowering::graph() const { return jsgraph()->graph(); }


Isolate* JSIntrinsicLowering::isolate() const { return jsgraph()->isolate(); }


CommonOperatorBuilder* JSIntrinsicLowering::common() const {
  return jsgraph()->common();
}

JSOperatorBuilder* JSIntrinsicLowering::javascript() const {
  return jsgraph_->javascript();
}

SimplifiedOperatorBuilder* JSIntrinsicLowering::simplified() const {
  return jsgraph()->simplified();
}

}  // namespace compiler
}  // namespace internal
}  // namespace v8