deps/v8/src/compiler/js-generic-lowering.cc

   1 // Copyright 2014 the V8 project authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "src/code-factory.h"
   6 #include "src/code-stubs.h"
   7 #include "src/compiler/common-operator.h"
   8 #include "src/compiler/js-generic-lowering.h"
   9 #include "src/compiler/js-graph.h"
  10 #include "src/compiler/machine-operator.h"
  11 #include "src/compiler/node-matchers.h"
  12 #include "src/compiler/node-properties.h"
  13 #include "src/compiler/operator-properties.h"
  14 #include "src/unique.h"
  15
  16 namespace v8 {
  17 namespace internal {
  18 namespace compiler {
  19
  20 JSGenericLowering::JSGenericLowering(bool is_typing_enabled, JSGraph* jsgraph)
  21     : is_typing_enabled_(is_typing_enabled), jsgraph_(jsgraph) {}
  22
  23
  24 JSGenericLowering::~JSGenericLowering() {}
  25
  26
  27 Reduction JSGenericLowering::Reduce(Node* node) {
  28   switch (node->opcode()) {
  29 #define DECLARE_CASE(x)  \
  30     case IrOpcode::k##x: \
  31       Lower##x(node);    \
  32       break;
  33     JS_OP_LIST(DECLARE_CASE)
  34 #undef DECLARE_CASE
  35     case IrOpcode::kBranch:
  36       // TODO(mstarzinger): If typing is enabled then simplified lowering will
  37       // have inserted the correct ChangeBoolToBit, otherwise we need to perform
  38       // poor-man's representation inference here and insert manual change.
  39       if (!is_typing_enabled_) {
  40         Node* condition = node->InputAt(0);
  41         if (condition->opcode() != IrOpcode::kAlways) {
  42           Node* test = graph()->NewNode(machine()->WordEqual(), condition,
  43                                         jsgraph()->TrueConstant());
  44           node->ReplaceInput(0, test);
  45         }
  46         break;
  47       }
  48       // Fall-through.
  49     default:
  50       // Nothing to see.
  51       return NoChange();
  52   }
  53   return Changed(node);
  54 }
  55
  56
  57 #define REPLACE_BINARY_OP_IC_CALL(op, token)                             \
  58   void JSGenericLowering::Lower##op(Node* node) {                        \
  59     ReplaceWithStubCall(node, CodeFactory::BinaryOpIC(isolate(), token), \
  60                         CallDescriptor::kPatchableCallSiteWithNop);      \
  61   }
  62 REPLACE_BINARY_OP_IC_CALL(JSBitwiseOr, Token::BIT_OR)
  63 REPLACE_BINARY_OP_IC_CALL(JSBitwiseXor, Token::BIT_XOR)
  64 REPLACE_BINARY_OP_IC_CALL(JSBitwiseAnd, Token::BIT_AND)
  65 REPLACE_BINARY_OP_IC_CALL(JSShiftLeft, Token::SHL)
  66 REPLACE_BINARY_OP_IC_CALL(JSShiftRight, Token::SAR)
  67 REPLACE_BINARY_OP_IC_CALL(JSShiftRightLogical, Token::SHR)
  68 REPLACE_BINARY_OP_IC_CALL(JSAdd, Token::ADD)
  69 REPLACE_BINARY_OP_IC_CALL(JSSubtract, Token::SUB)
  70 REPLACE_BINARY_OP_IC_CALL(JSMultiply, Token::MUL)
  71 REPLACE_BINARY_OP_IC_CALL(JSDivide, Token::DIV)
  72 REPLACE_BINARY_OP_IC_CALL(JSModulus, Token::MOD)
  73 #undef REPLACE_BINARY_OP_IC_CALL
  74
  75
  76 #define REPLACE_COMPARE_IC_CALL(op, token)        \
  77   void JSGenericLowering::Lower##op(Node* node) { \
  78     ReplaceWithCompareIC(node, token);            \
  79   }
  80 REPLACE_COMPARE_IC_CALL(JSEqual, Token::EQ)
  81 REPLACE_COMPARE_IC_CALL(JSNotEqual, Token::NE)
  82 REPLACE_COMPARE_IC_CALL(JSStrictEqual, Token::EQ_STRICT)
  83 REPLACE_COMPARE_IC_CALL(JSStrictNotEqual, Token::NE_STRICT)
  84 REPLACE_COMPARE_IC_CALL(JSLessThan, Token::LT)
  85 REPLACE_COMPARE_IC_CALL(JSGreaterThan, Token::GT)
  86 REPLACE_COMPARE_IC_CALL(JSLessThanOrEqual, Token::LTE)
  87 REPLACE_COMPARE_IC_CALL(JSGreaterThanOrEqual, Token::GTE)
  88 #undef REPLACE_COMPARE_IC_CALL
  89
  90
  91 #define REPLACE_RUNTIME_CALL(op, fun)             \
  92   void JSGenericLowering::Lower##op(Node* node) { \
  93     ReplaceWithRuntimeCall(node, fun);            \
  94   }
  95 REPLACE_RUNTIME_CALL(JSTypeOf, Runtime::kTypeof)
  96 REPLACE_RUNTIME_CALL(JSCreate, Runtime::kAbort)
  97 REPLACE_RUNTIME_CALL(JSCreateFunctionContext, Runtime::kNewFunctionContext)
  98 REPLACE_RUNTIME_CALL(JSCreateWithContext, Runtime::kPushWithContext)
  99 REPLACE_RUNTIME_CALL(JSCreateBlockContext, Runtime::kPushBlockContext)
 100 REPLACE_RUNTIME_CALL(JSCreateModuleContext, Runtime::kPushModuleContext)
 101 REPLACE_RUNTIME_CALL(JSCreateScriptContext, Runtime::kAbort)
 102 #undef REPLACE_RUNTIME
 103
 104
 105 #define REPLACE_UNIMPLEMENTED(op) \
 106   void JSGenericLowering::Lower##op(Node* node) { UNIMPLEMENTED(); }
 107 REPLACE_UNIMPLEMENTED(JSYield)
 108 #undef REPLACE_UNIMPLEMENTED
 109
 110
 111 static CallDescriptor::Flags FlagsForNode(Node* node) {
 112   CallDescriptor::Flags result = CallDescriptor::kNoFlags;
 113   if (OperatorProperties::GetFrameStateInputCount(node->op()) > 0) {
 114     result |= CallDescriptor::kNeedsFrameState;
 115   }
 116   return result;
 117 }
 118
 119
 120 void JSGenericLowering::ReplaceWithCompareIC(Node* node, Token::Value token) {
 121   Callable callable = CodeFactory::CompareIC(isolate(), token);
 122   CallDescriptor* desc_compare = Linkage::GetStubCallDescriptor(
 123       isolate(), zone(), callable.descriptor(), 0,
 124       CallDescriptor::kPatchableCallSiteWithNop | FlagsForNode(node),
 125       Operator::kNoProperties, kMachInt32);
 126
 127   // Create a new call node asking a CompareIC for help.
 128   NodeVector inputs(zone());
 129   inputs.reserve(node->InputCount() + 1);
 130   inputs.push_back(jsgraph()->HeapConstant(callable.code()));
 131   inputs.push_back(NodeProperties::GetValueInput(node, 0));
 132   inputs.push_back(NodeProperties::GetValueInput(node, 1));
 133   inputs.push_back(NodeProperties::GetContextInput(node));
 134   if (node->op()->HasProperty(Operator::kPure)) {
 135     // A pure (strict) comparison doesn't have an effect, control or frame
 136     // state.  But for the graph, we need to add control and effect inputs.
 137     DCHECK(OperatorProperties::GetFrameStateInputCount(node->op()) == 0);
 138     inputs.push_back(graph()->start());
 139     inputs.push_back(graph()->start());
 140   } else {
 141     DCHECK((OperatorProperties::GetFrameStateInputCount(node->op()) == 1) ==
 142            FLAG_turbo_deoptimization);
 143     if (FLAG_turbo_deoptimization) {
 144       inputs.push_back(NodeProperties::GetFrameStateInput(node, 0));
 145     }
 146     inputs.push_back(NodeProperties::GetEffectInput(node));
 147     inputs.push_back(NodeProperties::GetControlInput(node));
 148   }
 149   Node* compare =
 150       graph()->NewNode(common()->Call(desc_compare),
 151                        static_cast<int>(inputs.size()), &inputs.front());
 152   NodeProperties::SetBounds(
 153       compare, Bounds(Type::None(zone()), Type::UntaggedSigned(zone())));
 154
 155   // Decide how the return value from the above CompareIC can be converted into
 156   // a JavaScript boolean oddball depending on the given token.
 157   Node* false_value = jsgraph()->FalseConstant();
 158   Node* true_value = jsgraph()->TrueConstant();
 159   const Operator* op = nullptr;
 160   switch (token) {
 161     case Token::EQ:  // a == 0
 162     case Token::EQ_STRICT:
 163       op = machine()->WordEqual();
 164       break;
 165     case Token::NE:  // a != 0 becomes !(a == 0)
 166     case Token::NE_STRICT:
 167       op = machine()->WordEqual();
 168       std::swap(true_value, false_value);
 169       break;
 170     case Token::LT:  // a < 0
 171       op = machine()->IntLessThan();
 172       break;
 173     case Token::GT:  // a > 0 becomes !(a <= 0)
 174       op = machine()->IntLessThanOrEqual();
 175       std::swap(true_value, false_value);
 176       break;
 177     case Token::LTE:  // a <= 0
 178       op = machine()->IntLessThanOrEqual();
 179       break;
 180     case Token::GTE:  // a >= 0 becomes !(a < 0)
 181       op = machine()->IntLessThan();
 182       std::swap(true_value, false_value);
 183       break;
 184     default:
 185       UNREACHABLE();
 186   }
 187   Node* booleanize = graph()->NewNode(op, compare, jsgraph()->ZeroConstant());
 188
 189   // Finally patch the original node to select a boolean.
 190   NodeProperties::ReplaceWithValue(node, node, compare);
 191   // TODO(mstarzinger): Just a work-around because SelectLowering might
 192   // otherwise introduce a Phi without any uses, making Scheduler unhappy.
 193   if (node->UseCount() == 0) return;
 194   node->TrimInputCount(3);
 195   node->ReplaceInput(0, booleanize);
 196   node->ReplaceInput(1, true_value);
 197   node->ReplaceInput(2, false_value);
 198   node->set_op(common()->Select(kMachAnyTagged));
 199 }
 200
 201
 202 void JSGenericLowering::ReplaceWithStubCall(Node* node, Callable callable,
 203                                             CallDescriptor::Flags flags) {
 204   Operator::Properties properties = node->op()->properties();
 205   flags |= FlagsForNode(node);
 206   CallDescriptor* desc = Linkage::GetStubCallDescriptor(
 207       isolate(), zone(), callable.descriptor(), 0, flags, properties);
 208   const Operator* new_op = common()->Call(desc);
 209
 210   // Take care of frame states.
 211   int old_frame_state_count =
 212       OperatorProperties::GetFrameStateInputCount(node->op());
 213   int new_frame_state_count =
 214       (flags & CallDescriptor::kNeedsFrameState) ? 1 : 0;
 215   DCHECK_GE(old_frame_state_count, new_frame_state_count);
 216   // If there are extra frame states, get rid of them.
 217   for (int i = new_frame_state_count; i < old_frame_state_count; i++) {
 218     node->RemoveInput(NodeProperties::FirstFrameStateIndex(node) +
 219                       new_frame_state_count);
 220   }
 221
 222   Node* stub_code = jsgraph()->HeapConstant(callable.code());
 223   node->InsertInput(zone(), 0, stub_code);
 224   node->set_op(new_op);
 225 }
 226
 227
 228 void JSGenericLowering::ReplaceWithBuiltinCall(Node* node,
 229                                                Builtins::JavaScript id,
 230                                                int nargs) {
 231   Operator::Properties properties = node->op()->properties();
 232   Callable callable =
 233       CodeFactory::CallFunction(isolate(), nargs - 1, NO_CALL_FUNCTION_FLAGS);
 234   CallDescriptor* desc =
 235       Linkage::GetStubCallDescriptor(isolate(), zone(), callable.descriptor(),
 236                                      nargs, FlagsForNode(node), properties);
 237   Node* global_object = graph()->NewNode(
 238       machine()->Load(kMachAnyTagged), NodeProperties::GetContextInput(node),
 239       jsgraph()->IntPtrConstant(
 240           Context::SlotOffset(Context::GLOBAL_OBJECT_INDEX)),
 241       NodeProperties::GetEffectInput(node), graph()->start());
 242   Node* builtins_object = graph()->NewNode(
 243       machine()->Load(kMachAnyTagged), global_object,
 244       jsgraph()->IntPtrConstant(GlobalObject::kBuiltinsOffset - kHeapObjectTag),
 245       NodeProperties::GetEffectInput(node), graph()->start());
 246   Node* function = graph()->NewNode(
 247       machine()->Load(kMachAnyTagged), builtins_object,
 248       jsgraph()->IntPtrConstant(JSBuiltinsObject::OffsetOfFunctionWithId(id) -
 249                                 kHeapObjectTag),
 250       NodeProperties::GetEffectInput(node), graph()->start());
 251   Node* stub_code = jsgraph()->HeapConstant(callable.code());
 252   node->InsertInput(zone(), 0, stub_code);
 253   node->InsertInput(zone(), 1, function);
 254   node->set_op(common()->Call(desc));
 255 }
 256
 257
 258 void JSGenericLowering::ReplaceWithRuntimeCall(Node* node,
 259                                                Runtime::FunctionId f,
 260                                                int nargs_override) {
 261   Operator::Properties properties = node->op()->properties();
 262   const Runtime::Function* fun = Runtime::FunctionForId(f);
 263   int nargs = (nargs_override < 0) ? fun->nargs : nargs_override;
 264   CallDescriptor* desc =
 265       Linkage::GetRuntimeCallDescriptor(zone(), f, nargs, properties);
 266   Node* ref = jsgraph()->ExternalConstant(ExternalReference(f, isolate()));
 267   Node* arity = jsgraph()->Int32Constant(nargs);
 268   node->InsertInput(zone(), 0, jsgraph()->CEntryStubConstant(fun->result_size));
 269   node->InsertInput(zone(), nargs + 1, ref);
 270   node->InsertInput(zone(), nargs + 2, arity);
 271   node->set_op(common()->Call(desc));
 272 }
 273
 274
 275 void JSGenericLowering::LowerJSUnaryNot(Node* node) {
 276   Callable callable = CodeFactory::ToBoolean(
 277       isolate(), ToBooleanStub::RESULT_AS_INVERSE_ODDBALL);
 278   ReplaceWithStubCall(node, callable, CallDescriptor::kPatchableCallSite);
 279 }
 280
 281
 282 void JSGenericLowering::LowerJSToBoolean(Node* node) {
 283   Callable callable =
 284       CodeFactory::ToBoolean(isolate(), ToBooleanStub::RESULT_AS_ODDBALL);
 285   ReplaceWithStubCall(node, callable, CallDescriptor::kPatchableCallSite);
 286 }
 287
 288
 289 void JSGenericLowering::LowerJSToNumber(Node* node) {
 290   Callable callable = CodeFactory::ToNumber(isolate());
 291   ReplaceWithStubCall(node, callable, FlagsForNode(node));
 292 }
 293
 294
 295 void JSGenericLowering::LowerJSToString(Node* node) {
 296   ReplaceWithBuiltinCall(node, Builtins::TO_STRING, 1);
 297 }
 298
 299
 300 void JSGenericLowering::LowerJSToName(Node* node) {
 301   ReplaceWithBuiltinCall(node, Builtins::TO_NAME, 1);
 302 }
 303
 304
 305 void JSGenericLowering::LowerJSToObject(Node* node) {
 306   ReplaceWithBuiltinCall(node, Builtins::TO_OBJECT, 1);
 307 }
 308
 309
 310 void JSGenericLowering::LowerJSLoadProperty(Node* node) {
 311   const LoadPropertyParameters& p = LoadPropertyParametersOf(node->op());
 312   Callable callable =
 313       CodeFactory::KeyedLoadICInOptimizedCode(isolate(), UNINITIALIZED);
 314   if (FLAG_vector_ics) {
 315     node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
 316     node->InsertInput(zone(), 3,
 317                       jsgraph()->HeapConstant(p.feedback().vector()));
 318   }
 319   ReplaceWithStubCall(node, callable, CallDescriptor::kPatchableCallSite);
 320 }
 321
 322
 323 void JSGenericLowering::LowerJSLoadNamed(Node* node) {
 324   const LoadNamedParameters& p = LoadNamedParametersOf(node->op());
 325   Callable callable = CodeFactory::LoadICInOptimizedCode(
 326       isolate(), p.contextual_mode(), UNINITIALIZED);
 327   node->InsertInput(zone(), 1, jsgraph()->HeapConstant(p.name()));
 328   if (FLAG_vector_ics) {
 329     node->InsertInput(zone(), 2, jsgraph()->SmiConstant(p.feedback().index()));
 330     node->InsertInput(zone(), 3,
 331                       jsgraph()->HeapConstant(p.feedback().vector()));
 332   }
 333   ReplaceWithStubCall(node, callable, CallDescriptor::kPatchableCallSite);
 334 }
 335
 336
 337 void JSGenericLowering::LowerJSStoreProperty(Node* node) {
 338   LanguageMode language_mode = OpParameter<LanguageMode>(node);
 339   Callable callable = CodeFactory::KeyedStoreICInOptimizedCode(
 340       isolate(), language_mode, UNINITIALIZED);
 341   ReplaceWithStubCall(node, callable, CallDescriptor::kPatchableCallSite);
 342 }
 343
 344
 345 void JSGenericLowering::LowerJSStoreNamed(Node* node) {
 346   const StoreNamedParameters& p = StoreNamedParametersOf(node->op());
 347   Callable callable = CodeFactory::StoreIC(isolate(), p.language_mode());
 348   node->InsertInput(zone(), 1, jsgraph()->HeapConstant(p.name()));
 349   ReplaceWithStubCall(node, callable, CallDescriptor::kPatchableCallSite);
 350 }
 351
 352
 353 void JSGenericLowering::LowerJSDeleteProperty(Node* node) {
 354   LanguageMode language_mode = OpParameter<LanguageMode>(node);
 355   ReplaceWithBuiltinCall(node, Builtins::DELETE, 3);
 356   node->InsertInput(zone(), 4, jsgraph()->SmiConstant(language_mode));
 357 }
 358
 359
 360 void JSGenericLowering::LowerJSHasProperty(Node* node) {
 361   ReplaceWithBuiltinCall(node, Builtins::IN, 2);
 362 }
 363
 364
 365 void JSGenericLowering::LowerJSInstanceOf(Node* node) {
 366   InstanceofStub::Flags flags = static_cast<InstanceofStub::Flags>(
 367       InstanceofStub::kReturnTrueFalseObject |
 368       InstanceofStub::kArgsInRegisters);
 369   InstanceofStub stub(isolate(), flags);
 370   CallInterfaceDescriptor d = stub.GetCallInterfaceDescriptor();
 371   CallDescriptor* desc = Linkage::GetStubCallDescriptor(isolate(), zone(), d, 0,
 372                                                         FlagsForNode(node));
 373   Node* stub_code = jsgraph()->HeapConstant(stub.GetCode());
 374   node->InsertInput(zone(), 0, stub_code);
 375   node->set_op(common()->Call(desc));
 376 }
 377
 378
 379 void JSGenericLowering::LowerJSLoadContext(Node* node) {
 380   const ContextAccess& access = ContextAccessOf(node->op());
 381   for (size_t i = 0; i < access.depth(); ++i) {
 382     node->ReplaceInput(
 383         0, graph()->NewNode(machine()->Load(kMachAnyTagged),
 384                             NodeProperties::GetValueInput(node, 0),
 385                             jsgraph()->Int32Constant(
 386                                 Context::SlotOffset(Context::PREVIOUS_INDEX)),
 387                             NodeProperties::GetEffectInput(node),
 388                             graph()->start()));
 389   }
 390   node->ReplaceInput(1, jsgraph()->Int32Constant(Context::SlotOffset(
 391                             static_cast<int>(access.index()))));
 392   node->AppendInput(zone(), graph()->start());
 393   node->set_op(machine()->Load(kMachAnyTagged));
 394 }
 395
 396
 397 void JSGenericLowering::LowerJSStoreContext(Node* node) {
 398   const ContextAccess& access = ContextAccessOf(node->op());
 399   for (size_t i = 0; i < access.depth(); ++i) {
 400     node->ReplaceInput(
 401         0, graph()->NewNode(machine()->Load(kMachAnyTagged),
 402                             NodeProperties::GetValueInput(node, 0),
 403                             jsgraph()->Int32Constant(
 404                                 Context::SlotOffset(Context::PREVIOUS_INDEX)),
 405                             NodeProperties::GetEffectInput(node),
 406                             graph()->start()));
 407   }
 408   node->ReplaceInput(2, NodeProperties::GetValueInput(node, 1));
 409   node->ReplaceInput(1, jsgraph()->Int32Constant(Context::SlotOffset(
 410                             static_cast<int>(access.index()))));
 411   node->set_op(
 412       machine()->Store(StoreRepresentation(kMachAnyTagged, kFullWriteBarrier)));
 413 }
 414
 415
 416 void JSGenericLowering::LowerJSCreateCatchContext(Node* node) {
 417   Unique<String> name = OpParameter<Unique<String>>(node);
 418   node->InsertInput(zone(), 0, jsgraph()->HeapConstant(name));
 419   ReplaceWithRuntimeCall(node, Runtime::kPushCatchContext);
 420 }
 421
 422
 423 void JSGenericLowering::LowerJSCallConstruct(Node* node) {
 424   int arity = OpParameter<int>(node);
 425   CallConstructStub stub(isolate(), NO_CALL_CONSTRUCTOR_FLAGS);
 426   CallInterfaceDescriptor d = stub.GetCallInterfaceDescriptor();
 427   CallDescriptor* desc = Linkage::GetStubCallDescriptor(
 428       isolate(), zone(), d, arity, FlagsForNode(node));
 429   Node* stub_code = jsgraph()->HeapConstant(stub.GetCode());
 430   Node* construct = NodeProperties::GetValueInput(node, 0);
 431   node->InsertInput(zone(), 0, stub_code);
 432   node->InsertInput(zone(), 1, jsgraph()->Int32Constant(arity - 1));
 433   node->InsertInput(zone(), 2, construct);
 434   node->InsertInput(zone(), 3, jsgraph()->UndefinedConstant());
 435   node->set_op(common()->Call(desc));
 436 }
 437
 438
 439 bool JSGenericLowering::TryLowerDirectJSCall(Node* node) {
 440   // Lower to a direct call to a constant JSFunction if legal.
 441   const CallFunctionParameters& p = CallFunctionParametersOf(node->op());
 442   int arg_count = static_cast<int>(p.arity() - 2);
 443
 444   // Check the function is a constant and is really a JSFunction.
 445   HeapObjectMatcher<Object> function_const(node->InputAt(0));
 446   if (!function_const.HasValue()) return false;  // not a constant.
 447   Handle<Object> func = function_const.Value().handle();
 448   if (!func->IsJSFunction()) return false;  // not a function.
 449   Handle<JSFunction> function = Handle<JSFunction>::cast(func);
 450   if (arg_count != function->shared()->internal_formal_parameter_count()) {
 451     return false;
 452   }
 453
 454   // Check the receiver doesn't need to be wrapped.
 455   Node* receiver = node->InputAt(1);
 456   if (!NodeProperties::IsTyped(receiver)) return false;
 457   Type* ok_receiver = Type::Union(Type::Undefined(), Type::Receiver(), zone());
 458   if (!NodeProperties::GetBounds(receiver).upper->Is(ok_receiver)) return false;
 459
 460   int index = NodeProperties::FirstContextIndex(node);
 461
 462   // TODO(titzer): total hack to share function context constants.
 463   // Remove this when the JSGraph canonicalizes heap constants.
 464   Node* context = node->InputAt(index);
 465   HeapObjectMatcher<Context> context_const(context);
 466   if (!context_const.HasValue() ||
 467       *(context_const.Value().handle()) != function->context()) {
 468     context = jsgraph()->HeapConstant(Handle<Context>(function->context()));
 469   }
 470   node->ReplaceInput(index, context);
 471   CallDescriptor* desc = Linkage::GetJSCallDescriptor(
 472       zone(), false, 1 + arg_count, FlagsForNode(node));
 473   node->set_op(common()->Call(desc));
 474   return true;
 475 }
 476
 477
 478 void JSGenericLowering::LowerJSCallFunction(Node* node) {
 479   // Fast case: call function directly.
 480   if (TryLowerDirectJSCall(node)) return;
 481
 482   // General case: CallFunctionStub.
 483   const CallFunctionParameters& p = CallFunctionParametersOf(node->op());
 484   int arg_count = static_cast<int>(p.arity() - 2);
 485   CallFunctionStub stub(isolate(), arg_count, p.flags());
 486   CallInterfaceDescriptor d = stub.GetCallInterfaceDescriptor();
 487   CallDescriptor* desc = Linkage::GetStubCallDescriptor(
 488       isolate(), zone(), d, static_cast<int>(p.arity() - 1),
 489       FlagsForNode(node));
 490   Node* stub_code = jsgraph()->HeapConstant(stub.GetCode());
 491   node->InsertInput(zone(), 0, stub_code);
 492   node->set_op(common()->Call(desc));
 493 }
 494
 495
 496 void JSGenericLowering::LowerJSCallRuntime(Node* node) {
 497   const CallRuntimeParameters& p = CallRuntimeParametersOf(node->op());
 498   ReplaceWithRuntimeCall(node, p.id(), static_cast<int>(p.arity()));
 499 }
 500
 501
 502 void JSGenericLowering::LowerJSStackCheck(Node* node) {
 503   Node* effect = NodeProperties::GetEffectInput(node);
 504   Node* control = NodeProperties::GetControlInput(node);
 505
 506   Node* limit = graph()->NewNode(
 507       machine()->Load(kMachPtr),
 508       jsgraph()->ExternalConstant(
 509           ExternalReference::address_of_stack_limit(isolate())),
 510       jsgraph()->IntPtrConstant(0), effect, control);
 511   Node* pointer = graph()->NewNode(machine()->LoadStackPointer());
 512
 513   Node* check = graph()->NewNode(machine()->UintLessThan(), limit, pointer);
 514   Node* branch =
 515       graph()->NewNode(common()->Branch(BranchHint::kTrue), check, control);
 516
 517   Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
 518   Node* etrue = effect;
 519
 520   Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
 521   NodeProperties::ReplaceControlInput(node, if_false);
 522   Node* efalse = node;
 523
 524   Node* merge = graph()->NewNode(common()->Merge(2), if_true, if_false);
 525   Node* ephi = graph()->NewNode(common()->EffectPhi(2), etrue, efalse, merge);
 526
 527   // Relax controls of {node}, i.e. make it free floating.
 528   NodeProperties::ReplaceWithValue(node, node, ephi, merge);
 529   NodeProperties::ReplaceEffectInput(ephi, efalse, 1);
 530
 531   // Turn the stack check into a runtime call.
 532   ReplaceWithRuntimeCall(node, Runtime::kStackGuard);
 533 }
 534
 535
 536 Zone* JSGenericLowering::zone() const { return graph()->zone(); }
 537
 538
 539 Isolate* JSGenericLowering::isolate() const { return jsgraph()->isolate(); }
 540
 541
 542 Graph* JSGenericLowering::graph() const { return jsgraph()->graph(); }
 543
 544
 545 CommonOperatorBuilder* JSGenericLowering::common() const {
 546   return jsgraph()->common();
 547 }
 548
 549
 550 MachineOperatorBuilder* JSGenericLowering::machine() const {
 551   return jsgraph()->machine();
 552 }
 553
 554 }  // namespace compiler
 555 }  // namespace internal
 556 }  // namespace v8