Merge up to 8597 to experimental/gc from the bleeding edge.

src/arm/lithium-arm.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 50 matching lines @@
 
 #ifdef DEBUG
 void LInstruction::VerifyCall() {
   // Call instructions can use only fixed registers as temporaries and
   // outputs because all registers are blocked by the calling convention.
   // Inputs operands must use a fixed register or use-at-start policy or
   // a non-register policy.
   ASSERT(Output() == NULL ||
          LUnallocated::cast(Output())->HasFixedPolicy() ||
          !LUnallocated::cast(Output())->HasRegisterPolicy());
-  for (UseIterator it(this); it.HasNext(); it.Advance()) {
-    LUnallocated* operand = LUnallocated::cast(it.Next());
+  for (UseIterator it(this); !it.Done(); it.Advance()) {
+    LUnallocated* operand = LUnallocated::cast(it.Current());
     ASSERT(operand->HasFixedPolicy() ||
            operand->IsUsedAtStart());
   }
-  for (TempIterator it(this); it.HasNext(); it.Advance()) {
-    LUnallocated* operand = LUnallocated::cast(it.Next());
+  for (TempIterator it(this); !it.Done(); it.Advance()) {
+    LUnallocated* operand = LUnallocated::cast(it.Current());
     ASSERT(operand->HasFixedPolicy() ||!operand->HasRegisterPolicy());
   }
 }
 #endif
 
 
 void LOsrEntry::MarkSpilledDoubleRegister(int allocation_index,
                                           LOperand* spill_operand) {
   ASSERT(spill_operand->IsDoubleStackSlot());
   ASSERT(double_register_spills_[allocation_index] == NULL);
@@ skipping 16 matching lines @@
   if (HasPointerMap()) {
     stream->Add(" ");
     pointer_map()->PrintTo(stream);
   }
 }
 
 
 template<int R, int I, int T>
 void LTemplateInstruction<R, I, T>::PrintDataTo(StringStream* stream) {
   stream->Add("= ");
-  inputs_.PrintOperandsTo(stream);
+  for (int i = 0; i < inputs_.length(); i++) {
+    if (i > 0) stream->Add(" ");
+    inputs_[i]->PrintTo(stream);
+  }
 }
 
 
 template<int R, int I, int T>
 void LTemplateInstruction<R, I, T>::PrintOutputOperandTo(StringStream* stream) {
-  results_.PrintOperandsTo(stream);
-}
-
-
-template<typename T, int N>
-void OperandContainer<T, N>::PrintOperandsTo(StringStream* stream) {
-  for (int i = 0; i < N; i++) {
+  for (int i = 0; i < results_.length(); i++) {
     if (i > 0) stream->Add(" ");
-    elems_[i]->PrintTo(stream);
+    results_[i]->PrintTo(stream);
   }
 }
 
 
 void LLabel::PrintDataTo(StringStream* stream) {
   LGap::PrintDataTo(stream);
   LLabel* rep = replacement();
   if (rep != NULL) {
     stream->Add(" Dead block replaced with B%d", rep->block_id());
   }
@@ skipping 122 matching lines @@
 void LClassOfTestAndBranch::PrintDataTo(StringStream* stream) {
   stream->Add("if class_of_test(");
   InputAt(0)->PrintTo(stream);
   stream->Add(", \"%o\") then B%d else B%d",
               *hydrogen()->class_name(),
               true_block_id(),
               false_block_id());
 }
 
 
-void LTypeofIs::PrintDataTo(StringStream* stream) {
-  InputAt(0)->PrintTo(stream);
-  stream->Add(" == \"%s\"", *hydrogen()->type_literal()->ToCString());
-}
-
-
 void LTypeofIsAndBranch::PrintDataTo(StringStream* stream) {
   stream->Add("if typeof ");
   InputAt(0)->PrintTo(stream);
   stream->Add(" == \"%s\" then B%d else B%d",
               *hydrogen()->type_literal()->ToCString(),
               true_block_id(), false_block_id());
 }
 
 
 void LCallConstantFunction::PrintDataTo(StringStream* stream) {
@@ skipping 49 matching lines @@
 }
 
 
 void LCallNew::PrintDataTo(StringStream* stream) {
   stream->Add("= ");
   InputAt(0)->PrintTo(stream);
   stream->Add(" #%d / ", arity());
 }
 
 
-void LClassOfTest::PrintDataTo(StringStream* stream) {
-  stream->Add("= class_of_test(");
-  InputAt(0)->PrintTo(stream);
-  stream->Add(", \"%o\")", *hydrogen()->class_name());
-}
-
-
 void LAccessArgumentsAt::PrintDataTo(StringStream* stream) {
   arguments()->PrintTo(stream);
 
   stream->Add(" length ");
   length()->PrintTo(stream);
 
   stream->Add(" index ");
   index()->PrintTo(stream);
 }
 
@@ skipping 66 matching lines @@
   for (int i = 0; i < graph()->blocks()->length(); ++i) {
     HBasicBlock* block = graph()->blocks()->at(i);
     int first = block->first_instruction_index();
     int last = block->last_instruction_index();
     LInstruction* first_instr = instructions()->at(first);
     LInstruction* last_instr = instructions()->at(last);
 
     LLabel* label = LLabel::cast(first_instr);
     if (last_instr->IsGoto()) {
       LGoto* goto_instr = LGoto::cast(last_instr);
-      if (!goto_instr->include_stack_check() &&
-          label->IsRedundant() &&
+      if (label->IsRedundant() &&
           !label->is_loop_header()) {
         bool can_eliminate = true;
         for (int i = first + 1; i < last && can_eliminate; ++i) {
           LInstruction* cur = instructions()->at(i);
           if (cur->IsGap()) {
             LGap* gap = LGap::cast(cur);
             if (!gap->IsRedundant()) {
               can_eliminate = false;
             }
           } else {
@@ skipping 350 matching lines @@
   allocator_->RecordTemporary(operand);
   return operand;
 }
 
 
 LInstruction* LChunkBuilder::DoBlockEntry(HBlockEntry* instr) {
   return new LLabel(instr->block());
 }
 
 
+LInstruction* LChunkBuilder::DoSoftDeoptimize(HSoftDeoptimize* instr) {
+  return AssignEnvironment(new LDeoptimize);
+}
+
+
 LInstruction* LChunkBuilder::DoDeoptimize(HDeoptimize* instr) {
   return AssignEnvironment(new LDeoptimize);
 }
 
 
 LInstruction* LChunkBuilder::DoBit(Token::Value op,
                                    HBitwiseBinaryOperation* instr) {
   if (instr->representation().IsInteger32()) {
     ASSERT(instr->left()->representation().IsInteger32());
     ASSERT(instr->right()->representation().IsInteger32());
 
     LOperand* left = UseRegisterAtStart(instr->LeastConstantOperand());
     LOperand* right = UseOrConstantAtStart(instr->MostConstantOperand());
-    return DefineSameAsFirst(new LBitI(op, left, right));
+    return DefineAsRegister(new LBitI(op, left, right));
   } else {
     ASSERT(instr->representation().IsTagged());
     ASSERT(instr->left()->representation().IsTagged());
     ASSERT(instr->right()->representation().IsTagged());
 
     LOperand* left = UseFixed(instr->left(), r1);
     LOperand* right = UseFixed(instr->right(), r0);
     LArithmeticT* result = new LArithmeticT(op, left, right);
     return MarkAsCall(DefineFixed(result, r0), instr);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoShift(Token::Value op,
                                      HBitwiseBinaryOperation* instr) {
   if (instr->representation().IsTagged()) {
     ASSERT(instr->left()->representation().IsTagged());
     ASSERT(instr->right()->representation().IsTagged());
 
     LOperand* left = UseFixed(instr->left(), r1);
     LOperand* right = UseFixed(instr->right(), r0);
     LArithmeticT* result = new LArithmeticT(op, left, right);
     return MarkAsCall(DefineFixed(result, r0), instr);
   }
 
   ASSERT(instr->representation().IsInteger32());
-  ASSERT(instr->OperandAt(0)->representation().IsInteger32());
-  ASSERT(instr->OperandAt(1)->representation().IsInteger32());
-  LOperand* left = UseRegisterAtStart(instr->OperandAt(0));
+  ASSERT(instr->left()->representation().IsInteger32());
+  ASSERT(instr->right()->representation().IsInteger32());
+  LOperand* left = UseRegisterAtStart(instr->left());
 
-  HValue* right_value = instr->OperandAt(1);
+  HValue* right_value = instr->right();
   LOperand* right = NULL;
   int constant_value = 0;
   if (right_value->IsConstant()) {
     HConstant* constant = HConstant::cast(right_value);
     right = chunk_->DefineConstantOperand(constant);
     constant_value = constant->Integer32Value() & 0x1f;
   } else {
-    right = UseRegister(right_value);
+    right = UseRegisterAtStart(right_value);
   }
 
   // Shift operations can only deoptimize if we do a logical shift
   // by 0 and the result cannot be truncated to int32.
   bool may_deopt = (op == Token::SHR && constant_value == 0);
   bool does_deopt = false;
   if (may_deopt) {
     for (HUseIterator it(instr->uses()); !it.Done(); it.Advance()) {
       if (!it.value()->CheckFlag(HValue::kTruncatingToInt32)) {
         does_deopt = true;
         break;
       }
     }
   }
 
   LInstruction* result =
-      DefineSameAsFirst(new LShiftI(op, left, right, does_deopt));
+      DefineAsRegister(new LShiftI(op, left, right, does_deopt));
   return does_deopt ? AssignEnvironment(result) : result;
 }
 
 
 LInstruction* LChunkBuilder::DoArithmeticD(Token::Value op,
                                            HArithmeticBinaryOperation* instr) {
   ASSERT(instr->representation().IsDouble());
   ASSERT(instr->left()->representation().IsDouble());
   ASSERT(instr->right()->representation().IsDouble());
   ASSERT(op != Token::MOD);
   LOperand* left = UseRegisterAtStart(instr->left());
   LOperand* right = UseRegisterAtStart(instr->right());
   LArithmeticD* result = new LArithmeticD(op, left, right);
-  return DefineSameAsFirst(result);
+  return DefineAsRegister(result);
 }
 
 
 LInstruction* LChunkBuilder::DoArithmeticT(Token::Value op,
                                            HArithmeticBinaryOperation* instr) {
   ASSERT(op == Token::ADD ||
          op == Token::DIV ||
          op == Token::MOD ||
          op == Token::MUL ||
          op == Token::SUB);
@@ skipping 77 matching lines @@
   if (current->has_position()) position_ = current->position();
   LInstruction* instr = current->CompileToLithium(this);
 
   if (instr != NULL) {
     if (FLAG_stress_pointer_maps && !instr->HasPointerMap()) {
       instr = AssignPointerMap(instr);
     }
     if (FLAG_stress_environments && !instr->HasEnvironment()) {
       instr = AssignEnvironment(instr);
     }
-    if (current->IsTest() && !instr->IsGoto()) {
-      ASSERT(instr->IsControl());
-      HTest* test = HTest::cast(current);
-      instr->set_hydrogen_value(test->value());
-      HBasicBlock* first = test->FirstSuccessor();
-      HBasicBlock* second = test->SecondSuccessor();
-      ASSERT(first != NULL && second != NULL);
-      instr->SetBranchTargets(first->block_id(), second->block_id());
-    } else {
-      instr->set_hydrogen_value(current);
-    }
-
+    instr->set_hydrogen_value(current);
     chunk_->AddInstruction(instr, current_block_);
   }
   current_instruction_ = old_current;
 }
 
 
 LEnvironment* LChunkBuilder::CreateEnvironment(HEnvironment* hydrogen_env) {
   if (hydrogen_env == NULL) return NULL;
 
   LEnvironment* outer = CreateEnvironment(hydrogen_env->outer());
@@ skipping 20 matching lines @@
       op = UseAny(value);
     }
     result->AddValue(op, value->representation());
   }
 
   return result;
 }
 
 
 LInstruction* LChunkBuilder::DoGoto(HGoto* instr) {
-  LInstruction* result = new LGoto(instr->FirstSuccessor()->block_id(),
-                                   instr->include_stack_check());
-  if (instr->include_stack_check())  result = AssignPointerMap(result);
-  return result;
+  return new LGoto(instr->FirstSuccessor()->block_id());
 }
 
 
-LInstruction* LChunkBuilder::DoTest(HTest* instr) {
+LInstruction* LChunkBuilder::DoBranch(HBranch* instr) {
   HValue* v = instr->value();
-  if (!v->EmitAtUses()) {
-    return new LBranch(UseRegisterAtStart(v));
-  } else if (v->IsClassOfTest()) {
-    HClassOfTest* compare = HClassOfTest::cast(v);
-    ASSERT(compare->value()->representation().IsTagged());
-    return new LClassOfTestAndBranch(UseTempRegister(compare->value()),
-                                     TempRegister());
-  } else if (v->IsCompare()) {
-    HCompare* compare = HCompare::cast(v);
-    Token::Value op = compare->token();
-    HValue* left = compare->left();
-    HValue* right = compare->right();
-    Representation r = compare->GetInputRepresentation();
-    if (r.IsInteger32()) {
-      ASSERT(left->representation().IsInteger32());
-      ASSERT(right->representation().IsInteger32());
-      return new LCmpIDAndBranch(UseRegisterAtStart(left),
-                                 UseRegisterAtStart(right));
-    } else if (r.IsDouble()) {
-      ASSERT(left->representation().IsDouble());
-      ASSERT(right->representation().IsDouble());
-      return new LCmpIDAndBranch(UseRegisterAtStart(left),
-                                 UseRegisterAtStart(right));
-    } else {
-      ASSERT(left->representation().IsTagged());
-      ASSERT(right->representation().IsTagged());
-      bool reversed = op == Token::GT || op == Token::LTE;
-      LOperand* left_operand = UseFixed(left, reversed ? r0 : r1);
-      LOperand* right_operand = UseFixed(right, reversed ? r1 : r0);
-      LInstruction* result = new LCmpTAndBranch(left_operand, right_operand);
-      return MarkAsCall(result, instr);
-    }
-  } else if (v->IsIsSmi()) {
-    HIsSmi* compare = HIsSmi::cast(v);
-    ASSERT(compare->value()->representation().IsTagged());
-    return new LIsSmiAndBranch(Use(compare->value()));
-  } else if (v->IsIsUndetectable()) {
-    HIsUndetectable* compare = HIsUndetectable::cast(v);
-    ASSERT(compare->value()->representation().IsTagged());
-    return new LIsUndetectableAndBranch(UseRegisterAtStart(compare->value()),
-                                        TempRegister());
-  } else if (v->IsHasInstanceType()) {
-    HHasInstanceType* compare = HHasInstanceType::cast(v);
-    ASSERT(compare->value()->representation().IsTagged());
-    return new LHasInstanceTypeAndBranch(UseRegisterAtStart(compare->value()));
-  } else if (v->IsHasCachedArrayIndex()) {
-    HHasCachedArrayIndex* compare = HHasCachedArrayIndex::cast(v);
-    ASSERT(compare->value()->representation().IsTagged());
-    return new LHasCachedArrayIndexAndBranch(
-        UseRegisterAtStart(compare->value()));
-  } else if (v->IsIsNull()) {
-    HIsNull* compare = HIsNull::cast(v);
-    ASSERT(compare->value()->representation().IsTagged());
-    return new LIsNullAndBranch(UseRegisterAtStart(compare->value()));
-  } else if (v->IsIsObject()) {
-    HIsObject* compare = HIsObject::cast(v);
-    ASSERT(compare->value()->representation().IsTagged());
-    LOperand* temp = TempRegister();
-    return new LIsObjectAndBranch(UseRegisterAtStart(compare->value()), temp);
-  } else if (v->IsCompareJSObjectEq()) {
-    HCompareJSObjectEq* compare = HCompareJSObjectEq::cast(v);
-    return new LCmpJSObjectEqAndBranch(UseRegisterAtStart(compare->left()),
-                                       UseRegisterAtStart(compare->right()));
-  } else if (v->IsCompareSymbolEq()) {
-    HCompareSymbolEq* compare = HCompareSymbolEq::cast(v);
-    return new LCmpSymbolEqAndBranch(UseRegisterAtStart(compare->left()),
-                                     UseRegisterAtStart(compare->right()));
-  } else if (v->IsInstanceOf()) {
-    HInstanceOf* instance_of = HInstanceOf::cast(v);
-    LInstruction* result =
-        new LInstanceOfAndBranch(UseFixed(instance_of->left(), r0),
-                                 UseFixed(instance_of->right(), r1));
-    return MarkAsCall(result, instr);
-  } else if (v->IsTypeofIs()) {
-    HTypeofIs* typeof_is = HTypeofIs::cast(v);
-    return new LTypeofIsAndBranch(UseTempRegister(typeof_is->value()));
-  } else if (v->IsIsConstructCall()) {
-    return new LIsConstructCallAndBranch(TempRegister());
-  } else if (v->IsConstant()) {
+  if (v->EmitAtUses()) {
     HBasicBlock* successor = HConstant::cast(v)->ToBoolean()
         ? instr->FirstSuccessor()
         : instr->SecondSuccessor();
     return new LGoto(successor->block_id());
-  } else {
-    Abort("Undefined compare before branch");
-    return NULL;
   }
+  return new LBranch(UseRegisterAtStart(v));
 }
 
 
 
 LInstruction* LChunkBuilder::DoCompareMap(HCompareMap* instr) {
   ASSERT(instr->value()->representation().IsTagged());
   LOperand* value = UseRegisterAtStart(instr->value());
   LOperand* temp = TempRegister();
   return new LCmpMapAndBranch(value, temp);
 }
@@ skipping 13 matching lines @@
   LInstanceOf* result =
       new LInstanceOf(UseFixed(instr->left(), r0),
                       UseFixed(instr->right(), r1));
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoInstanceOfKnownGlobal(
     HInstanceOfKnownGlobal* instr) {
   LInstanceOfKnownGlobal* result =
-      new LInstanceOfKnownGlobal(UseFixed(instr->value(), r0), FixedTemp(r4));
+      new LInstanceOfKnownGlobal(UseFixed(instr->left(), r0), FixedTemp(r4));
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoApplyArguments(HApplyArguments* instr) {
   LOperand* function = UseFixed(instr->function(), r1);
   LOperand* receiver = UseFixed(instr->receiver(), r0);
   LOperand* length = UseFixed(instr->length(), r2);
   LOperand* elements = UseFixed(instr->elements(), r3);
   LApplyArguments* result = new LApplyArguments(function,
                                                 receiver,
                                                 length,
                                                 elements);
   return MarkAsCall(DefineFixed(result, r0), instr, CAN_DEOPTIMIZE_EAGERLY);
 }
 
 
 LInstruction* LChunkBuilder::DoPushArgument(HPushArgument* instr) {
   ++argument_count_;
   LOperand* argument = Use(instr->argument());
   return new LPushArgument(argument);
 }
 
 
+LInstruction* LChunkBuilder::DoThisFunction(HThisFunction* instr) {
+  return instr->HasNoUses() ? NULL : DefineAsRegister(new LThisFunction);
+}
+
+
 LInstruction* LChunkBuilder::DoContext(HContext* instr) {
   return instr->HasNoUses() ? NULL : DefineAsRegister(new LContext);
 }
 
 
 LInstruction* LChunkBuilder::DoOuterContext(HOuterContext* instr) {
   LOperand* context = UseRegisterAtStart(instr->value());
   return DefineAsRegister(new LOuterContext(context));
 }
 
@@ skipping 30 matching lines @@
   if (op == kMathLog || op == kMathSin || op == kMathCos) {
     LOperand* input = UseFixedDouble(instr->value(), d2);
     LUnaryMathOperation* result = new LUnaryMathOperation(input, NULL);
     return MarkAsCall(DefineFixedDouble(result, d2), instr);
   } else {
     LOperand* input = UseRegisterAtStart(instr->value());
     LOperand* temp = (op == kMathFloor) ? TempRegister() : NULL;
     LUnaryMathOperation* result = new LUnaryMathOperation(input, temp);
     switch (op) {
       case kMathAbs:
-        return AssignEnvironment(AssignPointerMap(DefineSameAsFirst(result)));
+        return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
       case kMathFloor:
         return AssignEnvironment(AssignPointerMap(DefineAsRegister(result)));
       case kMathSqrt:
-        return DefineSameAsFirst(result);
+        return DefineAsRegister(result);
       case kMathRound:
         return AssignEnvironment(DefineAsRegister(result));
       case kMathPowHalf:
-        return DefineSameAsFirst(result);
+        return DefineAsRegister(result);
       default:
         UNREACHABLE();
         return NULL;
     }
   }
 }
 
 
 LInstruction* LChunkBuilder::DoCallKeyed(HCallKeyed* instr) {
   ASSERT(instr->key()->representation().IsTagged());
@@ skipping 57 matching lines @@
 
 
 LInstruction* LChunkBuilder::DoBitAnd(HBitAnd* instr) {
   return DoBit(Token::BIT_AND, instr);
 }
 
 
 LInstruction* LChunkBuilder::DoBitNot(HBitNot* instr) {
   ASSERT(instr->value()->representation().IsInteger32());
   ASSERT(instr->representation().IsInteger32());
-  return DefineSameAsFirst(new LBitNotI(UseRegisterAtStart(instr->value())));
+  return DefineAsRegister(new LBitNotI(UseRegisterAtStart(instr->value())));
 }
 
 
 LInstruction* LChunkBuilder::DoBitOr(HBitOr* instr) {
   return DoBit(Token::BIT_OR, instr);
 }
 
 
 LInstruction* LChunkBuilder::DoBitXor(HBitXor* instr) {
   return DoBit(Token::BIT_XOR, instr);
@@ skipping 24 matching lines @@
     ASSERT(instr->left()->representation().IsInteger32());
     ASSERT(instr->right()->representation().IsInteger32());
 
     LModI* mod;
     if (instr->HasPowerOf2Divisor()) {
       ASSERT(!instr->CheckFlag(HValue::kCanBeDivByZero));
       LOperand* value = UseRegisterAtStart(instr->left());
       mod = new LModI(value, UseOrConstant(instr->right()));
     } else {
       LOperand* dividend = UseRegister(instr->left());
-      LOperand* divisor = UseRegisterAtStart(instr->right());
+      LOperand* divisor = UseRegister(instr->right());
       mod = new LModI(dividend,
                       divisor,
                       TempRegister(),
-                      FixedTemp(d1),
-                      FixedTemp(d2));
+                      FixedTemp(d10),
+                      FixedTemp(d11));
     }
 
-    return AssignEnvironment(DefineSameAsFirst(mod));
+    if (instr->CheckFlag(HValue::kBailoutOnMinusZero) ||
+        instr->CheckFlag(HValue::kCanBeDivByZero)) {
+      return AssignEnvironment(DefineAsRegister(mod));
+    } else {
+      return DefineAsRegister(mod);
+    }
   } else if (instr->representation().IsTagged()) {
     return DoArithmeticT(Token::MOD, instr);
   } else {
     ASSERT(instr->representation().IsDouble());
     // We call a C function for double modulo. It can't trigger a GC.
     // We need to use fixed result register for the call.
     // TODO(fschneider): Allow any register as input registers.
     LOperand* left = UseFixedDouble(instr->left(), d1);
     LOperand* right = UseFixedDouble(instr->right(), d2);
     LArithmeticD* result = new LArithmeticD(Token::MOD, left, right);
     return MarkAsCall(DefineFixedDouble(result, d1), instr);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoMul(HMul* instr) {
   if (instr->representation().IsInteger32()) {
     ASSERT(instr->left()->representation().IsInteger32());
     ASSERT(instr->right()->representation().IsInteger32());
-    LOperand* left = UseRegisterAtStart(instr->LeastConstantOperand());
+    LOperand* left;
     LOperand* right = UseOrConstant(instr->MostConstantOperand());
     LOperand* temp = NULL;
-    if (instr->CheckFlag(HValue::kBailoutOnMinusZero)) {
+    if (instr->CheckFlag(HValue::kBailoutOnMinusZero) &&
+        (instr->CheckFlag(HValue::kCanOverflow) ||
+        !right->IsConstantOperand())) {
+      left = UseRegister(instr->LeastConstantOperand());
       temp = TempRegister();
+    } else {
+      left = UseRegisterAtStart(instr->LeastConstantOperand());
     }
-    LMulI* mul = new LMulI(left, right, temp);
-    return AssignEnvironment(DefineSameAsFirst(mul));
+    return AssignEnvironment(DefineAsRegister(new LMulI(left, right, temp)));
+
   } else if (instr->representation().IsDouble()) {
     return DoArithmeticD(Token::MUL, instr);
+
   } else {
     return DoArithmeticT(Token::MUL, instr);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoSub(HSub* instr) {
   if (instr->representation().IsInteger32()) {
     ASSERT(instr->left()->representation().IsInteger32());
     ASSERT(instr->right()->representation().IsInteger32());
     LOperand* left = UseRegisterAtStart(instr->left());
     LOperand* right = UseOrConstantAtStart(instr->right());
     LSubI* sub = new LSubI(left, right);
-    LInstruction* result = DefineSameAsFirst(sub);
+    LInstruction* result = DefineAsRegister(sub);
     if (instr->CheckFlag(HValue::kCanOverflow)) {
       result = AssignEnvironment(result);
     }
     return result;
   } else if (instr->representation().IsDouble()) {
     return DoArithmeticD(Token::SUB, instr);
   } else {
     return DoArithmeticT(Token::SUB, instr);
   }
 }
 
 
 LInstruction* LChunkBuilder::DoAdd(HAdd* instr) {
   if (instr->representation().IsInteger32()) {
     ASSERT(instr->left()->representation().IsInteger32());
     ASSERT(instr->right()->representation().IsInteger32());
     LOperand* left = UseRegisterAtStart(instr->LeastConstantOperand());
     LOperand* right = UseOrConstantAtStart(instr->MostConstantOperand());
     LAddI* add = new LAddI(left, right);
-    LInstruction* result = DefineSameAsFirst(add);
+    LInstruction* result = DefineAsRegister(add);
     if (instr->CheckFlag(HValue::kCanOverflow)) {
       result = AssignEnvironment(result);
     }
     return result;
   } else if (instr->representation().IsDouble()) {
     return DoArithmeticD(Token::ADD, instr);
   } else {
     ASSERT(instr->representation().IsTagged());
     return DoArithmeticT(Token::ADD, instr);
   }
@@ skipping 10 matching lines @@
   LOperand* right = exponent_type.IsDouble() ?
       UseFixedDouble(instr->right(), d2) :
       UseFixed(instr->right(), r0);
   LPower* result = new LPower(left, right);
   return MarkAsCall(DefineFixedDouble(result, d3),
                     instr,
                     CAN_DEOPTIMIZE_EAGERLY);
 }
 
 
-LInstruction* LChunkBuilder::DoCompare(HCompare* instr) {
+LInstruction* LChunkBuilder::DoCompareGeneric(HCompareGeneric* instr) {
   Token::Value op = instr->token();
   Representation r = instr->GetInputRepresentation();
+  ASSERT(instr->left()->representation().IsTagged());
+  ASSERT(instr->right()->representation().IsTagged());
+  bool reversed = (op == Token::GT || op == Token::LTE);
+  LOperand* left = UseFixed(instr->left(), reversed ? r0 : r1);
+  LOperand* right = UseFixed(instr->right(), reversed ? r1 : r0);
+  LCmpT* result = new LCmpT(left, right);
+  return MarkAsCall(DefineFixed(result, r0), instr);
+}
+
+
+LInstruction* LChunkBuilder::DoCompareIDAndBranch(
+    HCompareIDAndBranch* instr) {
+  Representation r = instr->GetInputRepresentation();
   if (r.IsInteger32()) {
     ASSERT(instr->left()->representation().IsInteger32());
     ASSERT(instr->right()->representation().IsInteger32());
     LOperand* left = UseRegisterAtStart(instr->left());
     LOperand* right = UseRegisterAtStart(instr->right());
-    return DefineAsRegister(new LCmpID(left, right));
-  } else if (r.IsDouble()) {
+    return new LCmpIDAndBranch(left, right);
+  } else {
+    ASSERT(r.IsDouble());
     ASSERT(instr->left()->representation().IsDouble());
     ASSERT(instr->right()->representation().IsDouble());
     LOperand* left = UseRegisterAtStart(instr->left());
     LOperand* right = UseRegisterAtStart(instr->right());
-    return DefineAsRegister(new LCmpID(left, right));
-  } else {
-    ASSERT(instr->left()->representation().IsTagged());
-    ASSERT(instr->right()->representation().IsTagged());
-    bool reversed = (op == Token::GT || op == Token::LTE);
-    LOperand* left = UseFixed(instr->left(), reversed ? r0 : r1);
-    LOperand* right = UseFixed(instr->right(), reversed ? r1 : r0);
-    LCmpT* result = new LCmpT(left, right);
-    return MarkAsCall(DefineFixed(result, r0), instr);
+    return new LCmpIDAndBranch(left, right);
   }
 }
 
 
-LInstruction* LChunkBuilder::DoCompareJSObjectEq(
-    HCompareJSObjectEq* instr) {
+LInstruction* LChunkBuilder::DoCompareObjectEqAndBranch(
+    HCompareObjectEqAndBranch* instr) {
   LOperand* left = UseRegisterAtStart(instr->left());
   LOperand* right = UseRegisterAtStart(instr->right());
-  LCmpJSObjectEq* result = new LCmpJSObjectEq(left, right);
-  return DefineAsRegister(result);
+  return new LCmpObjectEqAndBranch(left, right);
 }
 
 
-LInstruction* LChunkBuilder::DoCompareSymbolEq(
-    HCompareSymbolEq* instr) {
-  LOperand* left = UseRegisterAtStart(instr->left());
-  LOperand* right = UseRegisterAtStart(instr->right());
-  LCmpSymbolEq* result = new LCmpSymbolEq(left, right);
-  return DefineAsRegister(result);
+LInstruction* LChunkBuilder::DoCompareConstantEqAndBranch(
+    HCompareConstantEqAndBranch* instr) {
+  return new LCmpConstantEqAndBranch(UseRegisterAtStart(instr->value()));
 }
 
 
-LInstruction* LChunkBuilder::DoIsNull(HIsNull* instr) {
+LInstruction* LChunkBuilder::DoIsNullAndBranch(HIsNullAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());
-  LOperand* value = UseRegisterAtStart(instr->value());
-
-  return DefineAsRegister(new LIsNull(value));
+  return new LIsNullAndBranch(UseRegisterAtStart(instr->value()));
 }
 
 
-LInstruction* LChunkBuilder::DoIsObject(HIsObject* instr) {
+LInstruction* LChunkBuilder::DoIsObjectAndBranch(HIsObjectAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());
-  LOperand* value = UseRegisterAtStart(instr->value());
-
-  return DefineAsRegister(new LIsObject(value));
+  LOperand* temp = TempRegister();
+  return new LIsObjectAndBranch(UseRegisterAtStart(instr->value()), temp);
 }
 
 
-LInstruction* LChunkBuilder::DoIsSmi(HIsSmi* instr) {
+LInstruction* LChunkBuilder::DoIsSmiAndBranch(HIsSmiAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());
-  LOperand* value = UseAtStart(instr->value());
-
-  return DefineAsRegister(new LIsSmi(value));
+  return new LIsSmiAndBranch(Use(instr->value()));
 }
 
 
-LInstruction* LChunkBuilder::DoIsUndetectable(HIsUndetectable* instr) {
+LInstruction* LChunkBuilder::DoIsUndetectableAndBranch(
+    HIsUndetectableAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());
-  LOperand* value = UseRegisterAtStart(instr->value());
-
-  return DefineAsRegister(new LIsUndetectable(value));
+  return new LIsUndetectableAndBranch(UseRegisterAtStart(instr->value()),
+                                      TempRegister());
 }
 
 
-LInstruction* LChunkBuilder::DoHasInstanceType(HHasInstanceType* instr) {
+LInstruction* LChunkBuilder::DoHasInstanceTypeAndBranch(
+    HHasInstanceTypeAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());
-  LOperand* value = UseRegisterAtStart(instr->value());
-
-  return DefineAsRegister(new LHasInstanceType(value));
+  return new LHasInstanceTypeAndBranch(UseRegisterAtStart(instr->value()));
 }
 
 
 LInstruction* LChunkBuilder::DoGetCachedArrayIndex(
     HGetCachedArrayIndex* instr)  {
   ASSERT(instr->value()->representation().IsTagged());
   LOperand* value = UseRegisterAtStart(instr->value());
 
   return DefineAsRegister(new LGetCachedArrayIndex(value));
 }
 
 
-LInstruction* LChunkBuilder::DoHasCachedArrayIndex(
-    HHasCachedArrayIndex* instr) {
+LInstruction* LChunkBuilder::DoHasCachedArrayIndexAndBranch(
+    HHasCachedArrayIndexAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());
-  LOperand* value = UseRegister(instr->value());
-
-  return DefineAsRegister(new LHasCachedArrayIndex(value));
+  return new LHasCachedArrayIndexAndBranch(
+      UseRegisterAtStart(instr->value()));
 }
 
 
-LInstruction* LChunkBuilder::DoClassOfTest(HClassOfTest* instr) {
+LInstruction* LChunkBuilder::DoClassOfTestAndBranch(
+    HClassOfTestAndBranch* instr) {
   ASSERT(instr->value()->representation().IsTagged());
-  LOperand* value = UseTempRegister(instr->value());
-  return DefineSameAsFirst(new LClassOfTest(value));
+  return new LClassOfTestAndBranch(UseTempRegister(instr->value()),
+                                   TempRegister());
 }
 
 
 LInstruction* LChunkBuilder::DoJSArrayLength(HJSArrayLength* instr) {
   LOperand* array = UseRegisterAtStart(instr->value());
   return DefineAsRegister(new LJSArrayLength(array));
 }
 
 
 LInstruction* LChunkBuilder::DoExternalArrayLength(
     HExternalArrayLength* instr) {
   LOperand* array = UseRegisterAtStart(instr->value());
   return DefineAsRegister(new LExternalArrayLength(array));
 }
 
 
 LInstruction* LChunkBuilder::DoFixedArrayLength(HFixedArrayLength* instr) {
   LOperand* array = UseRegisterAtStart(instr->value());
   return DefineAsRegister(new LFixedArrayLength(array));
 }
 
 
+LInstruction* LChunkBuilder::DoElementsKind(HElementsKind* instr) {
+  LOperand* object = UseRegisterAtStart(instr->value());
+  return DefineAsRegister(new LElementsKind(object));
+}
+
+
 LInstruction* LChunkBuilder::DoValueOf(HValueOf* instr) {
   LOperand* object = UseRegister(instr->value());
   LValueOf* result = new LValueOf(object, TempRegister());
-  return AssignEnvironment(DefineSameAsFirst(result));
+  return AssignEnvironment(DefineAsRegister(result));
 }
 
 
 LInstruction* LChunkBuilder::DoBoundsCheck(HBoundsCheck* instr) {
   return AssignEnvironment(new LBoundsCheck(UseRegisterAtStart(instr->index()),
                                             UseRegister(instr->length())));
 }
 
 
 LInstruction* LChunkBuilder::DoAbnormalExit(HAbnormalExit* instr) {
   // The control instruction marking the end of a block that completed
   // abruptly (e.g., threw an exception).  There is nothing specific to do.
   return NULL;
 }
 
 
 LInstruction* LChunkBuilder::DoThrow(HThrow* instr) {
   LOperand* value = UseFixed(instr->value(), r0);
   return MarkAsCall(new LThrow(value), instr);
 }
 
 
+LInstruction* LChunkBuilder::DoUseConst(HUseConst* instr) {
+  return NULL;
+}
+
+
 LInstruction* LChunkBuilder::DoForceRepresentation(HForceRepresentation* bad) {
   // All HForceRepresentation instructions should be eliminated in the
   // representation change phase of Hydrogen.
   UNREACHABLE();
   return NULL;
 }
 
 
 LInstruction* LChunkBuilder::DoChange(HChange* instr) {
   Representation from = instr->from();
   Representation to = instr->to();
   if (from.IsTagged()) {
     if (to.IsDouble()) {
       LOperand* value = UseRegister(instr->value());
       LNumberUntagD* res = new LNumberUntagD(value);
       return AssignEnvironment(DefineAsRegister(res));
     } else {
       ASSERT(to.IsInteger32());
       LOperand* value = UseRegister(instr->value());
       bool needs_check = !instr->value()->type().IsSmi();
       LInstruction* res = NULL;
       if (!needs_check) {
         res = DefineSameAsFirst(new LSmiUntag(value, needs_check));
       } else {
         LOperand* temp1 = TempRegister();
         LOperand* temp2 = instr->CanTruncateToInt32() ? TempRegister()
                                                       : NULL;
-        LOperand* temp3 = instr->CanTruncateToInt32() ? FixedTemp(d3)
+        LOperand* temp3 = instr->CanTruncateToInt32() ? FixedTemp(d11)
                                                       : NULL;
         res = DefineSameAsFirst(new LTaggedToI(value, temp1, temp2, temp3));
         res = AssignEnvironment(res);
       }
       return res;
     }
   } else if (from.IsDouble()) {
     if (to.IsTagged()) {
       LOperand* value = UseRegister(instr->value());
       LOperand* temp1 = TempRegister();
@@ skipping 73 matching lines @@
   LInstruction* result = new LCheckMap(value);
   return AssignEnvironment(result);
 }
 
 
 LInstruction* LChunkBuilder::DoClampToUint8(HClampToUint8* instr) {
   HValue* value = instr->value();
   Representation input_rep = value->representation();
   LOperand* reg = UseRegister(value);
   if (input_rep.IsDouble()) {
-    return DefineAsRegister(new LClampDToUint8(reg, FixedTemp(d1)));
+    return DefineAsRegister(new LClampDToUint8(reg, FixedTemp(d11)));
   } else if (input_rep.IsInteger32()) {
     return DefineAsRegister(new LClampIToUint8(reg));
   } else {
     ASSERT(input_rep.IsTagged());
     // Register allocator doesn't (yet) support allocation of double
     // temps. Reserve d1 explicitly.
-    LClampTToUint8* result = new LClampTToUint8(reg, FixedTemp(d1));
+    LClampTToUint8* result = new LClampTToUint8(reg, FixedTemp(d11));
     return AssignEnvironment(DefineAsRegister(result));
   }
 }
 
 
+LInstruction* LChunkBuilder::DoToInt32(HToInt32* instr) {
+  HValue* value = instr->value();
+  Representation input_rep = value->representation();
+  LOperand* reg = UseRegister(value);
+  if (input_rep.IsDouble()) {
+    LOperand* temp1 = TempRegister();
+    LOperand* temp2 = TempRegister();
+    LDoubleToI* res = new LDoubleToI(reg, temp1, temp2);
+    return AssignEnvironment(DefineAsRegister(res));
+  } else if (input_rep.IsInteger32()) {
+    // Canonicalization should already have removed the hydrogen instruction in
+    // this case, since it is a noop.
+    UNREACHABLE();
+    return NULL;
+  } else {
+    ASSERT(input_rep.IsTagged());
+    LOperand* temp1 = TempRegister();
+    LOperand* temp2 = TempRegister();
+    LOperand* temp3 = FixedTemp(d11);
+    LTaggedToI* res = new LTaggedToI(reg, temp1, temp2, temp3);
+    return AssignEnvironment(DefineSameAsFirst(res));
+  }
+}
+
+
 LInstruction* LChunkBuilder::DoReturn(HReturn* instr) {
   return new LReturn(UseFixed(instr->value(), r0));
 }
 
 
 LInstruction* LChunkBuilder::DoConstant(HConstant* instr) {
   Representation r = instr->representation();
   if (r.IsInteger32()) {
     return DefineAsRegister(new LConstantI);
   } else if (r.IsDouble()) {
@@ skipping 111 matching lines @@
 }
 
 
 LInstruction* LChunkBuilder::DoLoadKeyedFastElement(
     HLoadKeyedFastElement* instr) {
   ASSERT(instr->representation().IsTagged());
   ASSERT(instr->key()->representation().IsInteger32());
   LOperand* obj = UseRegisterAtStart(instr->object());
   LOperand* key = UseRegisterAtStart(instr->key());
   LLoadKeyedFastElement* result = new LLoadKeyedFastElement(obj, key);
-  return AssignEnvironment(DefineSameAsFirst(result));
+  return AssignEnvironment(DefineAsRegister(result));
 }
 
 
 LInstruction* LChunkBuilder::DoLoadKeyedSpecializedArrayElement(
     HLoadKeyedSpecializedArrayElement* instr) {
-  ExternalArrayType array_type = instr->array_type();
+  JSObject::ElementsKind elements_kind = instr->elements_kind();
   Representation representation(instr->representation());
   ASSERT(
-      (representation.IsInteger32() && (array_type != kExternalFloatArray &&
-                                        array_type != kExternalDoubleArray)) ||
-      (representation.IsDouble() && (array_type == kExternalFloatArray ||
-                                     array_type == kExternalDoubleArray)));
+      (representation.IsInteger32() &&
+       (elements_kind != JSObject::EXTERNAL_FLOAT_ELEMENTS) &&
+       (elements_kind != JSObject::EXTERNAL_DOUBLE_ELEMENTS)) ||
+      (representation.IsDouble() &&
+       ((elements_kind == JSObject::EXTERNAL_FLOAT_ELEMENTS) ||
+       (elements_kind == JSObject::EXTERNAL_DOUBLE_ELEMENTS))));
   ASSERT(instr->key()->representation().IsInteger32());
   LOperand* external_pointer = UseRegister(instr->external_pointer());
   LOperand* key = UseRegisterOrConstant(instr->key());
   LLoadKeyedSpecializedArrayElement* result =
       new LLoadKeyedSpecializedArrayElement(external_pointer, key);
   LInstruction* load_instr = DefineAsRegister(result);
   // An unsigned int array load might overflow and cause a deopt, make sure it
   // has an environment.
-  return (array_type == kExternalUnsignedIntArray) ?
+  return (elements_kind == JSObject::EXTERNAL_UNSIGNED_INT_ELEMENTS) ?
       AssignEnvironment(load_instr) : load_instr;
 }
 
 
 LInstruction* LChunkBuilder::DoLoadKeyedGeneric(HLoadKeyedGeneric* instr) {
   LOperand* object = UseFixed(instr->object(), r1);
   LOperand* key = UseFixed(instr->key(), r0);
 
   LInstruction* result =
       DefineFixed(new LLoadKeyedGeneric(object, key), r0);
@@ skipping 16 matching lines @@
       ? UseTempRegister(instr->key())
       : UseRegisterOrConstantAtStart(instr->key());
 
   return AssignEnvironment(new LStoreKeyedFastElement(obj, key, val));
 }
 
 
 LInstruction* LChunkBuilder::DoStoreKeyedSpecializedArrayElement(
     HStoreKeyedSpecializedArrayElement* instr) {
   Representation representation(instr->value()->representation());
-  ExternalArrayType array_type = instr->array_type();
+  JSObject::ElementsKind elements_kind = instr->elements_kind();
   ASSERT(
-      (representation.IsInteger32() && (array_type != kExternalFloatArray &&
-                                        array_type != kExternalDoubleArray)) ||
-      (representation.IsDouble() && (array_type == kExternalFloatArray ||
-                                     array_type == kExternalDoubleArray)));
+      (representation.IsInteger32() &&
+       (elements_kind != JSObject::EXTERNAL_FLOAT_ELEMENTS) &&
+       (elements_kind != JSObject::EXTERNAL_DOUBLE_ELEMENTS)) ||
+      (representation.IsDouble() &&
+       ((elements_kind == JSObject::EXTERNAL_FLOAT_ELEMENTS) ||
+       (elements_kind == JSObject::EXTERNAL_DOUBLE_ELEMENTS))));
   ASSERT(instr->external_pointer()->representation().IsExternal());
   ASSERT(instr->key()->representation().IsInteger32());
 
   LOperand* external_pointer = UseRegister(instr->external_pointer());
-  bool val_is_temp_register = array_type == kExternalPixelArray ||
-      array_type == kExternalFloatArray;
+  bool val_is_temp_register =
+      elements_kind == JSObject::EXTERNAL_PIXEL_ELEMENTS ||
+      elements_kind == JSObject::EXTERNAL_FLOAT_ELEMENTS;
   LOperand* val = val_is_temp_register
       ? UseTempRegister(instr->value())
       : UseRegister(instr->value());
   LOperand* key = UseRegisterOrConstant(instr->key());
 
   return new LStoreKeyedSpecializedArrayElement(external_pointer,
                                                 key,
                                                 val);
 }
 
@@ skipping 99 matching lines @@
 
 
 LInstruction* LChunkBuilder::DoParameter(HParameter* instr) {
   int spill_index = chunk()->GetParameterStackSlot(instr->index());
   return DefineAsSpilled(new LParameter, spill_index);
 }
 
 
 LInstruction* LChunkBuilder::DoUnknownOSRValue(HUnknownOSRValue* instr) {
   int spill_index = chunk()->GetNextSpillIndex(false);  // Not double-width.
+  if (spill_index > LUnallocated::kMaxFixedIndex) {
+    Abort("Too many spill slots needed for OSR");
+    spill_index = 0;
+  }
   return DefineAsSpilled(new LUnknownOSRValue, spill_index);
 }
 
 
 LInstruction* LChunkBuilder::DoCallStub(HCallStub* instr) {
   argument_count_ -= instr->argument_count();
   return MarkAsCall(DefineFixed(new LCallStub, r0), instr);
 }
 
 
@@ skipping 21 matching lines @@
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
 
 LInstruction* LChunkBuilder::DoTypeof(HTypeof* instr) {
   LTypeof* result = new LTypeof(UseFixed(instr->value(), r0));
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
 
-LInstruction* LChunkBuilder::DoTypeofIs(HTypeofIs* instr) {
-  return DefineSameAsFirst(new LTypeofIs(UseRegister(instr->value())));
+LInstruction* LChunkBuilder::DoTypeofIsAndBranch(HTypeofIsAndBranch* instr) {
+  return new LTypeofIsAndBranch(UseTempRegister(instr->value()));
 }
 
 
-LInstruction* LChunkBuilder::DoIsConstructCall(HIsConstructCall* instr) {
-  return DefineAsRegister(new LIsConstructCall());
+LInstruction* LChunkBuilder::DoIsConstructCallAndBranch(
+    HIsConstructCallAndBranch* instr) {
+  return new LIsConstructCallAndBranch(TempRegister());
 }
 
 
 LInstruction* LChunkBuilder::DoSimulate(HSimulate* instr) {
   HEnvironment* env = current_block_->last_environment();
   ASSERT(env != NULL);
 
   env->set_ast_id(instr->ast_id());
 
   env->Drop(instr->pop_count());
@@ skipping 15 matching lines @@
         set_deoptimization_environment(result->environment());
     ClearInstructionPendingDeoptimizationEnvironment();
     return result;
   }
 
   return NULL;
 }
 
 
 LInstruction* LChunkBuilder::DoStackCheck(HStackCheck* instr) {
-  return MarkAsCall(new LStackCheck, instr);
+  if (instr->is_function_entry()) {
+    return MarkAsCall(new LStackCheck, instr);
+  } else {
+    ASSERT(instr->is_backwards_branch());
+    return AssignEnvironment(AssignPointerMap(new LStackCheck));
+  }
 }
 
 
 LInstruction* LChunkBuilder::DoEnterInlined(HEnterInlined* instr) {
   HEnvironment* outer = current_block_->last_environment();
   HConstant* undefined = graph()->GetConstantUndefined();
   HEnvironment* inner = outer->CopyForInlining(instr->closure(),
                                                instr->function(),
-                                               HEnvironment::LITHIUM,
                                                undefined,
                                                instr->call_kind());
   current_block_->UpdateEnvironment(inner);
   chunk_->AddInlinedClosure(instr->closure());
   return NULL;
 }
 
 
 LInstruction* LChunkBuilder::DoLeaveInlined(HLeaveInlined* instr) {
   HEnvironment* outer = current_block_->last_environment()->outer();
   current_block_->UpdateEnvironment(outer);
   return NULL;
 }
 
 
 LInstruction* LChunkBuilder::DoIn(HIn* instr) {
   LOperand* key = UseRegisterAtStart(instr->key());
   LOperand* object = UseRegisterAtStart(instr->object());
   LIn* result = new LIn(key, object);
   return MarkAsCall(DefineFixed(result, r0), instr);
 }
 
 
 } }  // namespace v8::internal