// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

#include "vm/globals.h"  // Needed here to get TARGET_ARCH_DBC.
#if defined(TARGET_ARCH_DBC)

#include "vm/intermediate_language.h"

#include "vm/cpu.h"
#include "vm/compiler.h"
#include "vm/dart_entry.h"
#include "vm/flow_graph.h"
#include "vm/flow_graph_compiler.h"
#include "vm/flow_graph_range_analysis.h"
#include "vm/locations.h"
#include "vm/object_store.h"
#include "vm/parser.h"
#include "vm/simulator.h"
#include "vm/stack_frame.h"
#include "vm/stub_code.h"
#include "vm/symbols.h"

#define __ compiler->assembler()->

namespace dart {

DECLARE_FLAG(bool, emit_edge_counters);
DECLARE_FLAG(int, optimization_counter_threshold);

// List of instructions that are still unimplemented by DBC backend.
#define FOR_EACH_UNIMPLEMENTED_INSTRUCTION(M)                                  \
  M(LoadCodeUnits)                                                             \
  M(BinaryInt32Op)                                                             \
  M(Int32ToDouble)                                                             \
  M(DoubleToInteger)                                                           \
  M(BoxInt64)                                                                  \
  M(MergedMath)                                                                \
  M(GuardFieldClass)                                                           \
  M(GuardFieldLength)                                                          \
  M(IfThenElse)                                                                \
  M(ExtractNthOutput)                                                          \
  M(BinaryUint32Op)                                                            \
  M(ShiftUint32Op)                                                             \
  M(UnaryUint32Op)                                                             \
  M(UnboxedIntConverter)

// List of instructions that are not used by DBC.
// Things we aren't planning to implement for DBC:
// - Unboxed SIMD,
// - Unboxed Mint,
// - Optimized RegExps,
// - Precompilation.
#define FOR_EACH_UNREACHABLE_INSTRUCTION(M)                                    \
  M(CaseInsensitiveCompareUC16)                                                \
  M(GenericCheckBound)                                                         \
  M(GrowRegExpStack)                                                           \
  M(IndirectGoto)                                                              \
  M(MintToDouble)                                                              \
  M(BinaryMintOp)                                                              \
  M(ShiftMintOp)                                                               \
  M(UnaryMintOp)                                                               \
  M(BinaryFloat32x4Op)                                                         \
  M(Simd32x4Shuffle)                                                           \
  M(Simd32x4ShuffleMix)                                                        \
  M(Simd32x4GetSignMask)                                                       \
  M(Float32x4Constructor)                                                      \
  M(Float32x4Zero)                                                             \
  M(Float32x4Splat)                                                            \
  M(Float32x4Comparison)                                                       \
  M(Float32x4MinMax)                                                           \
  M(Float32x4Scale)                                                            \
  M(Float32x4Sqrt)                                                             \
  M(Float32x4ZeroArg)                                                          \
  M(Float32x4Clamp)                                                            \
  M(Float32x4With)                                                             \
  M(Float32x4ToInt32x4)                                                        \
  M(Int32x4Constructor)                                                        \
  M(Int32x4BoolConstructor)                                                    \
  M(Int32x4GetFlag)                                                            \
  M(Int32x4Select)                                                             \
  M(Int32x4SetFlag)                                                            \
  M(Int32x4ToFloat32x4)                                                        \
  M(BinaryInt32x4Op)                                                           \
  M(BinaryFloat64x2Op)                                                         \
  M(Float64x2Zero)                                                             \
  M(Float64x2Constructor)                                                      \
  M(Float64x2Splat)                                                            \
  M(Float32x4ToFloat64x2)                                                      \
  M(Float64x2ToFloat32x4)                                                      \
  M(Simd64x2Shuffle)                                                           \
  M(Float64x2ZeroArg)                                                          \
  M(Float64x2OneArg)                                                           \
  M(CheckedSmiOp)                                                              \
  M(CheckedSmiComparison)

// Location summaries actually are not used by the unoptimizing DBC compiler
// because we don't allocate any registers.
static LocationSummary* CreateLocationSummary(
    Zone* zone,
    intptr_t num_inputs,
    Location output = Location::NoLocation(),
    LocationSummary::ContainsCall contains_call = LocationSummary::kNoCall,
    intptr_t num_temps = 0) {
  LocationSummary* locs =
      new (zone) LocationSummary(zone, num_inputs, num_temps, contains_call);
  for (intptr_t i = 0; i < num_inputs; i++) {
    locs->set_in(i, (contains_call == LocationSummary::kNoCall)
                        ? Location::RequiresRegister()
                        : Location::RegisterLocation(i));
  }
  for (intptr_t i = 0; i < num_temps; i++) {
    locs->set_temp(i, Location::RequiresRegister());
  }
  if (!output.IsInvalid()) {
    // For instructions that call we default to returning result in R0.
    locs->set_out(0, output);
  }
  return locs;
}


#define DEFINE_MAKE_LOCATION_SUMMARY(Name, ...)                                \
  LocationSummary* Name##Instr::MakeLocationSummary(Zone* zone, bool opt)      \
      const {                                                                  \
    return CreateLocationSummary(zone, __VA_ARGS__);                           \
  }

#define EMIT_NATIVE_CODE(Name, ...)                                            \
  DEFINE_MAKE_LOCATION_SUMMARY(Name, __VA_ARGS__);                             \
  void Name##Instr::EmitNativeCode(FlowGraphCompiler* compiler)

#define DEFINE_UNIMPLEMENTED_MAKE_LOCATION_SUMMARY(Name)                       \
  LocationSummary* Name##Instr::MakeLocationSummary(Zone* zone, bool opt)      \
      const {                                                                  \
    if (!opt) UNIMPLEMENTED();                                                 \
    return NULL;                                                               \
  }

#define DEFINE_UNREACHABLE_MAKE_LOCATION_SUMMARY(Name)                         \
  LocationSummary* Name##Instr::MakeLocationSummary(Zone* zone, bool opt)      \
      const {                                                                  \
    UNREACHABLE();                                                             \
    return NULL;                                                               \
  }

#define DEFINE_UNIMPLEMENTED_EMIT_NATIVE_CODE(Name)                            \
  void Name##Instr::EmitNativeCode(FlowGraphCompiler* compiler) {              \
    UNIMPLEMENTED();                                                           \
  }

#define DEFINE_UNREACHABLE_EMIT_NATIVE_CODE(Name)                              \
  void Name##Instr::EmitNativeCode(FlowGraphCompiler* compiler) {              \
    UNREACHABLE();                                                             \
  }

#define DEFINE_UNIMPLEMENTED_EMIT_BRANCH_CODE(Name)                            \
  void Name##Instr::EmitBranchCode(FlowGraphCompiler*, BranchInstr*) {         \
    UNIMPLEMENTED();                                                           \
  }                                                                            \
  Condition Name##Instr::EmitComparisonCode(FlowGraphCompiler*,                \
                                            BranchLabels) {                    \
    UNIMPLEMENTED();                                                           \
    return NEXT_IS_TRUE;                                                       \
  }

#define DEFINE_UNIMPLEMENTED(Name)                                             \
  DEFINE_UNIMPLEMENTED_MAKE_LOCATION_SUMMARY(Name)                             \
  DEFINE_UNIMPLEMENTED_EMIT_NATIVE_CODE(Name)

FOR_EACH_UNIMPLEMENTED_INSTRUCTION(DEFINE_UNIMPLEMENTED)

#undef DEFINE_UNIMPLEMENTED

#define DEFINE_UNREACHABLE(Name)                                               \
  DEFINE_UNREACHABLE_MAKE_LOCATION_SUMMARY(Name)                               \
  DEFINE_UNREACHABLE_EMIT_NATIVE_CODE(Name)

FOR_EACH_UNREACHABLE_INSTRUCTION(DEFINE_UNREACHABLE)

#undef DEFINE_UNREACHABLE


// Only used in AOT compilation.
DEFINE_UNIMPLEMENTED_EMIT_BRANCH_CODE(CheckedSmiComparison)


EMIT_NATIVE_CODE(InstanceOf,
                 2,
                 Location::SameAsFirstInput(),
                 LocationSummary::kCall) {
  SubtypeTestCache& test_cache = SubtypeTestCache::Handle();
  if (!type().IsVoidType() && type().IsInstantiated()) {
    test_cache = SubtypeTestCache::New();
  }

  if (compiler->is_optimizing()) {
    __ Push(locs()->in(0).reg());  // Value.
    __ Push(locs()->in(1).reg());  // Instantiator type arguments.
  }

  __ PushConstant(type());
  __ PushConstant(test_cache);
  __ InstanceOf(negate_result() ? 1 : 0);
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, deopt_id(),
                                 token_pos());
  compiler->RecordAfterCall(this);
  if (compiler->is_optimizing()) {
    __ PopLocal(locs()->out(0).reg());
  }
}


DEFINE_MAKE_LOCATION_SUMMARY(AssertAssignable,
                             2,
                             Location::SameAsFirstInput(),
                             LocationSummary::kCall);


EMIT_NATIVE_CODE(AssertBoolean,
                 1,
                 Location::SameAsFirstInput(),
                 LocationSummary::kCall) {
  if (compiler->is_optimizing()) {
    __ Push(locs()->in(0).reg());
  }
  __ AssertBoolean(Isolate::Current()->type_checks() ? 1 : 0);
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, deopt_id(),
                                 token_pos());
  compiler->RecordAfterCall(this);
  if (compiler->is_optimizing()) {
    __ Drop1();
  }
}


EMIT_NATIVE_CODE(PolymorphicInstanceCall,
                 0,
                 Location::RegisterLocation(0),
                 LocationSummary::kCall) {
  ASSERT(ic_data().NumArgsTested() == 1);
  const Array& arguments_descriptor = Array::Handle(ArgumentsDescriptor::New(
      instance_call()->ArgumentCount(), instance_call()->argument_names()));
  const intptr_t argdesc_kidx = __ AddConstant(arguments_descriptor);

  // Push the target onto the stack.
  if (with_checks()) {
    const intptr_t may_be_smi =
        (ic_data().GetReceiverClassIdAt(0) == kSmiCid) ? 1 : 0;
    GrowableArray<CidTarget> sorted_ic_data;
    FlowGraphCompiler::SortICDataByCount(ic_data(), &sorted_ic_data,
                                         /* drop_smi = */ true);
    const intptr_t sorted_length = sorted_ic_data.length();
    if (!Utils::IsUint(8, sorted_length)) {
      Unsupported(compiler);
      UNREACHABLE();
    }
    __ PushPolymorphicInstanceCall(instance_call()->ArgumentCount(),
                                   sorted_length + may_be_smi);
    if (may_be_smi == 1) {
      const Function& target =
          Function::ZoneHandle(compiler->zone(), ic_data().GetTargetAt(0));
      __ Nop(compiler->ToEmbeddableCid(kSmiCid, this));
      __ Nop(__ AddConstant(target));
    }
    for (intptr_t i = 0; i < sorted_length; i++) {
      const Function& target = *sorted_ic_data[i].target;
      __ Nop(compiler->ToEmbeddableCid(sorted_ic_data[i].cid, this));
      __ Nop(__ AddConstant(target));
    }
    compiler->EmitDeopt(deopt_id(),
                        ICData::kDeoptPolymorphicInstanceCallTestFail, 0);
  } else {
    ASSERT(ic_data().HasOneTarget());
    const Function& target = Function::ZoneHandle(ic_data().GetTargetAt(0));
    __ PushConstant(target);
  }

  // Call the function.
  __ StaticCall(instance_call()->ArgumentCount(), argdesc_kidx);
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, deopt_id(),
                                 instance_call()->token_pos());
  compiler->RecordAfterCall(this);
  __ PopLocal(locs()->out(0).reg());
}


EMIT_NATIVE_CODE(Stop, 0) {
  __ Stop(message());
}


EMIT_NATIVE_CODE(CheckStackOverflow,
                 0,
                 Location::NoLocation(),
                 LocationSummary::kCall) {
  __ CheckStack();
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, deopt_id(),
                                 token_pos());
  compiler->RecordAfterCall(this);
}


EMIT_NATIVE_CODE(PushArgument, 1) {
  if (compiler->is_optimizing()) {
    __ Push(locs()->in(0).reg());
  }
}


EMIT_NATIVE_CODE(LoadLocal, 0) {
  ASSERT(!compiler->is_optimizing());
  ASSERT(local().index() != 0);
  __ Push((local().index() > 0) ? (-local().index()) : (-local().index() - 1));
}


EMIT_NATIVE_CODE(StoreLocal, 0) {
  ASSERT(!compiler->is_optimizing());
  ASSERT(local().index() != 0);
  if (HasTemp()) {
    __ StoreLocal((local().index() > 0) ? (-local().index())
                                        : (-local().index() - 1));
  } else {
    __ PopLocal((local().index() > 0) ? (-local().index())
                                      : (-local().index() - 1));
  }
}


EMIT_NATIVE_CODE(LoadClassId, 1, Location::RequiresRegister()) {
  if (compiler->is_optimizing()) {
    __ LoadClassId(locs()->out(0).reg(), locs()->in(0).reg());
  } else {
    __ LoadClassIdTOS();
  }
}


EMIT_NATIVE_CODE(Constant, 0, Location::RequiresRegister()) {
  if (compiler->is_optimizing()) {
    if (locs()->out(0).IsRegister()) {
      __ LoadConstant(locs()->out(0).reg(), value());
    }
  } else {
    __ PushConstant(value());
  }
}


EMIT_NATIVE_CODE(UnboxedConstant, 0, Location::RequiresRegister()) {
  // The register allocator drops constant definitions that have no uses.
  if (locs()->out(0).IsInvalid()) {
    return;
  }
  if (representation_ != kUnboxedDouble) {
    Unsupported(compiler);
    UNREACHABLE();
  }
  const Register result = locs()->out(0).reg();
  if (Utils::DoublesBitEqual(Double::Cast(value()).value(), 0.0)) {
    __ BitXor(result, result, result);
  } else {
    __ LoadConstant(result, value());
    __ UnboxDouble(result, result);
  }
}


EMIT_NATIVE_CODE(Return, 1) {
  if (compiler->is_optimizing()) {
    __ Return(locs()->in(0).reg());
  } else {
    __ ReturnTOS();
  }
}


LocationSummary* StoreStaticFieldInstr::MakeLocationSummary(Zone* zone,
                                                            bool opt) const {
  const intptr_t kNumInputs = 1;
  const intptr_t kNumTemps = 1;
  LocationSummary* locs = new (zone)
      LocationSummary(zone, kNumInputs, kNumTemps, LocationSummary::kNoCall);
  for (intptr_t i = 0; i < kNumInputs; i++) {
    locs->set_in(i, Location::RequiresRegister());
  }
  for (intptr_t i = 0; i < kNumTemps; i++) {
    locs->set_temp(i, Location::RequiresRegister());
  }
  return locs;
}


void StoreStaticFieldInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
  if (compiler->is_optimizing()) {
    __ LoadConstant(locs()->temp(0).reg(),
                    Field::ZoneHandle(field().Original()));
    __ StoreField(locs()->temp(0).reg(),
                  Field::static_value_offset() / kWordSize,
                  locs()->in(0).reg());
  } else {
    const intptr_t kidx = __ AddConstant(field());
    __ StoreStaticTOS(kidx);
  }
}


EMIT_NATIVE_CODE(LoadStaticField, 1, Location::RequiresRegister()) {
  if (compiler->is_optimizing()) {
    __ LoadField(locs()->out(0).reg(), locs()->in(0).reg(),
                 Field::static_value_offset() / kWordSize);
  } else {
    const intptr_t kidx = __ AddConstant(StaticField());
    __ PushStatic(kidx);
  }
}


EMIT_NATIVE_CODE(InitStaticField,
                 1,
                 Location::NoLocation(),
                 LocationSummary::kCall) {
  if (compiler->is_optimizing()) {
    __ Push(locs()->in(0).reg());
    __ InitStaticTOS();
  } else {
    __ InitStaticTOS();
  }
  compiler->RecordAfterCall(this);
}


EMIT_NATIVE_CODE(ClosureCall,
                 1,
                 Location::RegisterLocation(0),
                 LocationSummary::kCall) {
  if (compiler->is_optimizing()) {
    __ Push(locs()->in(0).reg());
  }

  intptr_t argument_count = ArgumentCount();
  const Array& arguments_descriptor = Array::ZoneHandle(
      ArgumentsDescriptor::New(argument_count, argument_names()));
  const intptr_t argdesc_kidx =
      compiler->assembler()->AddConstant(arguments_descriptor);
  __ StaticCall(argument_count, argdesc_kidx);
  compiler->RecordAfterCall(this);
  if (compiler->is_optimizing()) {
    __ PopLocal(locs()->out(0).reg());
  }
}


static void EmitBranchOnCondition(FlowGraphCompiler* compiler,
                                  Condition true_condition,
                                  BranchLabels labels) {
  if (true_condition == NEXT_IS_TRUE) {
    // NEXT_IS_TRUE indicates that the preceeding test expects the true case
    // to be in the subsequent instruction, which it skips if the test fails.
    __ Jump(labels.true_label);
    if (labels.fall_through != labels.false_label) {
      // The preceeding Jump instruction will be skipped if the test fails.
      // If we aren't falling through to the false case, then we have to do
      // a Jump to it here.
      __ Jump(labels.false_label);
    }
  } else {
    ASSERT(true_condition == NEXT_IS_FALSE);
    // NEXT_IS_FALSE indicates that the preceeding test has been flipped and
    // expects the false case to be in the subsequent instruction, which it
    // skips if the test succeeds.
    __ Jump(labels.false_label);
    if (labels.fall_through != labels.true_label) {
      // The preceeding Jump instruction will be skipped if the test succeeds.
      // If we aren't falling through to the true case, then we have to do
      // a Jump to it here.
      __ Jump(labels.true_label);
    }
  }
}


Condition StrictCompareInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
                                                 BranchLabels labels) {
  ASSERT((kind() == Token::kNE_STRICT) || (kind() == Token::kEQ_STRICT));

  Token::Kind comparison;
  Condition condition;
  if (labels.fall_through == labels.false_label) {
    condition = NEXT_IS_TRUE;
    comparison = kind();
  } else {
    // Flip comparison to save a jump.
    condition = NEXT_IS_FALSE;
    comparison =
        (kind() == Token::kEQ_STRICT) ? Token::kNE_STRICT : Token::kEQ_STRICT;
  }

  if (!compiler->is_optimizing()) {
    const Bytecode::Opcode eq_op = needs_number_check()
                                       ? Bytecode::kIfEqStrictNumTOS
                                       : Bytecode::kIfEqStrictTOS;
    const Bytecode::Opcode ne_op = needs_number_check()
                                       ? Bytecode::kIfNeStrictNumTOS
                                       : Bytecode::kIfNeStrictTOS;
    __ Emit(comparison == Token::kEQ_STRICT ? eq_op : ne_op);
  } else {
    const Bytecode::Opcode eq_op =
        needs_number_check() ? Bytecode::kIfEqStrictNum : Bytecode::kIfEqStrict;
    const Bytecode::Opcode ne_op =
        needs_number_check() ? Bytecode::kIfNeStrictNum : Bytecode::kIfNeStrict;
    __ Emit(Bytecode::Encode((comparison == Token::kEQ_STRICT) ? eq_op : ne_op,
                             locs()->in(0).reg(), locs()->in(1).reg()));
  }

  if (needs_number_check() && token_pos().IsReal()) {
    compiler->RecordSafepoint(locs());
    compiler->AddCurrentDescriptor(RawPcDescriptors::kRuntimeCall,
                                   Thread::kNoDeoptId, token_pos());
  }

  return condition;
}


void StrictCompareInstr::EmitBranchCode(FlowGraphCompiler* compiler,
                                        BranchInstr* branch) {
  ASSERT((kind() == Token::kEQ_STRICT) || (kind() == Token::kNE_STRICT));

  BranchLabels labels = compiler->CreateBranchLabels(branch);
  Condition true_condition = EmitComparisonCode(compiler, labels);
  EmitBranchOnCondition(compiler, true_condition, labels);
}


EMIT_NATIVE_CODE(StrictCompare,
                 2,
                 Location::RequiresRegister(),
                 needs_number_check() ? LocationSummary::kCall
                                      : LocationSummary::kNoCall) {
  ASSERT((kind() == Token::kEQ_STRICT) || (kind() == Token::kNE_STRICT));

  Label is_true, is_false;
  BranchLabels labels = {&is_true, &is_false, &is_false};
  Condition true_condition = EmitComparisonCode(compiler, labels);
  EmitBranchOnCondition(compiler, true_condition, labels);
  Label done;
  if (compiler->is_optimizing()) {
    const Register result = locs()->out(0).reg();
    __ Bind(&is_false);
    __ LoadConstant(result, Bool::False());
    __ Jump(&done);
    __ Bind(&is_true);
    __ LoadConstant(result, Bool::True());
    __ Bind(&done);
  } else {
    __ Bind(&is_false);
    __ PushConstant(Bool::False());
    __ Jump(&done);
    __ Bind(&is_true);
    __ PushConstant(Bool::True());
    __ Bind(&done);
  }
}


LocationSummary* BranchInstr::MakeLocationSummary(Zone* zone, bool opt) const {
  comparison()->InitializeLocationSummary(zone, opt);
  if (!comparison()->HasLocs()) {
    return NULL;
  }
  // Branches don't produce a result.
  comparison()->locs()->set_out(0, Location::NoLocation());
  return comparison()->locs();
}


void BranchInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
  comparison()->EmitBranchCode(compiler, this);
}


EMIT_NATIVE_CODE(Goto, 0) {
  if (!compiler->is_optimizing()) {
    // Add a deoptimization descriptor for deoptimizing instructions that
    // may be inserted before this instruction.
    compiler->AddCurrentDescriptor(RawPcDescriptors::kDeopt, GetDeoptId(),
                                   TokenPosition::kNoSource);
  }
  if (HasParallelMove()) {
    compiler->parallel_move_resolver()->EmitNativeCode(parallel_move());
  }
  // We can fall through if the successor is the next block in the list.
  // Otherwise, we need a jump.
  if (!compiler->CanFallThroughTo(successor())) {
    __ Jump(compiler->GetJumpLabel(successor()));
  }
}


Condition TestSmiInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
                                           BranchLabels labels) {
  ASSERT((kind() == Token::kEQ) || (kind() == Token::kNE));
  Register left = locs()->in(0).reg();
  Register right = locs()->in(1).reg();
  __ TestSmi(left, right);
  return (kind() == Token::kEQ) ? NEXT_IS_TRUE : NEXT_IS_FALSE;
}


void TestSmiInstr::EmitBranchCode(FlowGraphCompiler* compiler,
                                  BranchInstr* branch) {
  BranchLabels labels = compiler->CreateBranchLabels(branch);
  Condition true_condition = EmitComparisonCode(compiler, labels);
  EmitBranchOnCondition(compiler, true_condition, labels);
}


EMIT_NATIVE_CODE(TestSmi,
                 2,
                 Location::RequiresRegister(),
                 LocationSummary::kNoCall) {
  // Never emitted outside of the BranchInstr.
  UNREACHABLE();
}


Condition TestCidsInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
                                            BranchLabels labels) {
  ASSERT((kind() == Token::kIS) || (kind() == Token::kISNOT));
  const Register value = locs()->in(0).reg();
  const intptr_t true_result = (kind() == Token::kIS) ? 1 : 0;

  const ZoneGrowableArray<intptr_t>& data = cid_results();
  const intptr_t num_cases = data.length() / 2;
  ASSERT(num_cases <= 255);
  __ TestCids(value, num_cases);

  bool result = false;
  for (intptr_t i = 0; i < data.length(); i += 2) {
    const intptr_t test_cid = data[i];
    result = data[i + 1] == true_result;
    __ Nop(result ? 1 : 0, compiler->ToEmbeddableCid(test_cid, this));
  }

  // No match found, deoptimize or false.
  if (CanDeoptimize()) {
    compiler->EmitDeopt(deopt_id(), ICData::kDeoptTestCids,
                        licm_hoisted_ ? ICData::kHoisted : 0);
  } else {
    Label* target = result ? labels.false_label : labels.true_label;
    __ Jump(target);
  }

  return NEXT_IS_TRUE;
}


void TestCidsInstr::EmitBranchCode(FlowGraphCompiler* compiler,
                                   BranchInstr* branch) {
  BranchLabels labels = compiler->CreateBranchLabels(branch);
  Condition true_condition = EmitComparisonCode(compiler, labels);
  EmitBranchOnCondition(compiler, true_condition, labels);
}


EMIT_NATIVE_CODE(TestCids,
                 1,
                 Location::RequiresRegister(),
                 LocationSummary::kNoCall) {
  Register result_reg = locs()->out(0).reg();
  Label is_true, is_false, done;
  BranchLabels labels = {&is_true, &is_false, &is_false};
  EmitComparisonCode(compiler, labels);
  __ Jump(&is_true);
  __ Bind(&is_false);
  __ LoadConstant(result_reg, Bool::False());
  __ Jump(&done);
  __ Bind(&is_true);
  __ LoadConstant(result_reg, Bool::True());
  __ Bind(&done);
}


EMIT_NATIVE_CODE(CreateArray,
                 2,
                 Location::RequiresRegister(),
                 LocationSummary::kCall) {
  if (compiler->is_optimizing()) {
    const Register length = locs()->in(kLengthPos).reg();
    const Register type_arguments = locs()->in(kElementTypePos).reg();
    const Register out = locs()->out(0).reg();
    __ CreateArrayOpt(out, length, type_arguments);
    __ Push(type_arguments);
    __ Push(length);
    __ CreateArrayTOS();
    compiler->RecordAfterCall(this);
    __ PopLocal(out);
  } else {
    __ CreateArrayTOS();
    compiler->RecordAfterCall(this);
  }
}


EMIT_NATIVE_CODE(StoreIndexed,
                 3,
                 Location::NoLocation(),
                 LocationSummary::kNoCall,
                 1) {
  if (!compiler->is_optimizing()) {
    ASSERT(class_id() == kArrayCid);
    __ StoreIndexedTOS();
    return;
  }
  const Register array = locs()->in(kArrayPos).reg();
  const Register index = locs()->in(kIndexPos).reg();
  const Register value = locs()->in(kValuePos).reg();
  const Register temp = locs()->temp(0).reg();
  switch (class_id()) {
    case kArrayCid:
      __ StoreIndexed(array, index, value);
      break;
    case kTypedDataUint8ArrayCid:
    case kTypedDataInt8ArrayCid:
    case kExternalOneByteStringCid:
    case kExternalTypedDataUint8ArrayCid:
      ASSERT(index_scale() == 1);
      if (IsExternal()) {
        __ StoreIndexedExternalUint8(array, index, value);
      } else {
        __ StoreIndexedUint8(array, index, value);
      }
      break;
    case kOneByteStringCid:
      ASSERT(index_scale() == 1);
      __ StoreIndexedOneByteString(array, index, value);
      break;
    case kTypedDataInt32ArrayCid:
    case kTypedDataUint32ArrayCid: {
      if (IsExternal()) {
        Unsupported(compiler);
        UNREACHABLE();
      }
      if (index_scale() == 1) {
        __ StoreIndexedUint32(array, index, value);
      } else {
        __ ShlImm(temp, index, Utils::ShiftForPowerOfTwo(index_scale()));
        __ StoreIndexedUint32(array, temp, value);
      }
      break;
    }
    case kTypedDataFloat32ArrayCid:
      if (IsExternal()) {
        Unsupported(compiler);
        UNREACHABLE();
      }
      if (index_scale() == 1) {
        __ StoreIndexedFloat32(array, index, value);
      } else if (index_scale() == 4) {
        __ StoreIndexed4Float32(array, index, value);
      } else {
        __ ShlImm(temp, index, Utils::ShiftForPowerOfTwo(index_scale()));
        __ StoreIndexedFloat32(array, temp, value);
      }
      break;
    case kTypedDataFloat64ArrayCid:
      if (IsExternal()) {
        Unsupported(compiler);
        UNREACHABLE();
      }
      if (index_scale() == 1) {
        __ StoreIndexedFloat64(array, index, value);
      } else if (index_scale() == 8) {
        __ StoreIndexed8Float64(array, index, value);
      } else {
        __ ShlImm(temp, index, Utils::ShiftForPowerOfTwo(index_scale()));
        __ StoreIndexedFloat64(array, temp, value);
      }
      break;
    default:
      Unsupported(compiler);
      UNREACHABLE();
      break;
  }
}


EMIT_NATIVE_CODE(LoadIndexed,
                 2,
                 Location::RequiresRegister(),
                 LocationSummary::kNoCall,
                 1) {
  ASSERT(compiler->is_optimizing());
  const Register array = locs()->in(0).reg();
  const Register index = locs()->in(1).reg();
  const Register temp = locs()->temp(0).reg();
  const Register result = locs()->out(0).reg();
  switch (class_id()) {
    case kArrayCid:
    case kImmutableArrayCid:
      __ LoadIndexed(result, array, index);
      break;
    case kTypedDataUint8ArrayCid:
    case kTypedDataUint8ClampedArrayCid:
    case kExternalOneByteStringCid:
    case kExternalTypedDataUint8ArrayCid:
    case kExternalTypedDataUint8ClampedArrayCid:
      ASSERT(index_scale() == 1);
      if (IsExternal()) {
        __ LoadIndexedExternalUint8(result, array, index);
      } else {
        __ LoadIndexedUint8(result, array, index);
      }
      break;
    case kTypedDataInt8ArrayCid:
      ASSERT(index_scale() == 1);
      if (IsExternal()) {
        __ LoadIndexedExternalInt8(result, array, index);
      } else {
        __ LoadIndexedInt8(result, array, index);
      }
      break;
    case kOneByteStringCid:
      ASSERT(index_scale() == 1);
      __ LoadIndexedOneByteString(result, array, index);
      break;
    case kTwoByteStringCid:
      if (index_scale() != 2) {
        // TODO(zra): Fix-up index.
        Unsupported(compiler);
        UNREACHABLE();
      }
      if (IsExternal()) {
        Unsupported(compiler);
        UNREACHABLE();
      }
      __ LoadIndexedTwoByteString(result, array, index);
      break;
    case kTypedDataInt32ArrayCid:
      ASSERT(representation() == kUnboxedInt32);
      if (IsExternal()) {
        Unsupported(compiler);
        UNREACHABLE();
      }
      if (index_scale() == 1) {
        __ LoadIndexedInt32(result, array, index);
      } else {
        __ ShlImm(temp, index, Utils::ShiftForPowerOfTwo(index_scale()));
        __ LoadIndexedInt32(result, array, temp);
      }
      break;
    case kTypedDataUint32ArrayCid:
      ASSERT(representation() == kUnboxedUint32);
      if (IsExternal()) {
        Unsupported(compiler);
        UNREACHABLE();
      }
      if (index_scale() == 1) {
        __ LoadIndexedUint32(result, array, index);
      } else {
        __ ShlImm(temp, index, Utils::ShiftForPowerOfTwo(index_scale()));
        __ LoadIndexedUint32(result, array, temp);
      }
      break;
    case kTypedDataFloat32ArrayCid:
      if (IsExternal()) {
        Unsupported(compiler);
        UNREACHABLE();
      }
      if (index_scale() == 1) {
        __ LoadIndexedFloat32(result, array, index);
      } else if (index_scale() == 4) {
        __ LoadIndexed4Float32(result, array, index);
      } else {
        __ ShlImm(temp, index, Utils::ShiftForPowerOfTwo(index_scale()));
        __ LoadIndexedFloat32(result, array, temp);
      }
      break;
    case kTypedDataFloat64ArrayCid:
      if (IsExternal()) {
        Unsupported(compiler);
        UNREACHABLE();
      }
      if (index_scale() == 1) {
        __ LoadIndexedFloat64(result, array, index);
      } else if (index_scale() == 8) {
        __ LoadIndexed8Float64(result, array, index);
      } else {
        __ ShlImm(temp, index, Utils::ShiftForPowerOfTwo(index_scale()));
        __ LoadIndexedFloat64(result, array, temp);
      }
      break;
    default:
      Unsupported(compiler);
      UNREACHABLE();
      break;
  }
}


EMIT_NATIVE_CODE(StringInterpolate,
                 1,
                 Location::RegisterLocation(0),
                 LocationSummary::kCall) {
  if (compiler->is_optimizing()) {
    __ Push(locs()->in(0).reg());
  }
  const intptr_t kArgumentCount = 1;
  const Array& arguments_descriptor = Array::Handle(
      ArgumentsDescriptor::New(kArgumentCount, Object::null_array()));
  __ PushConstant(CallFunction());
  const intptr_t argdesc_kidx = __ AddConstant(arguments_descriptor);
  __ StaticCall(kArgumentCount, argdesc_kidx);
  compiler->RecordAfterCall(this);
  if (compiler->is_optimizing()) {
    __ PopLocal(locs()->out(0).reg());
  }
}


EMIT_NATIVE_CODE(NativeCall,
                 0,
                 Location::NoLocation(),
                 LocationSummary::kCall) {
  SetupNative();

  const intptr_t argc_tag = NativeArguments::ComputeArgcTag(function());

  ASSERT(!link_lazily());
  const ExternalLabel label(reinterpret_cast<uword>(native_c_function()));
  const intptr_t target_kidx =
      __ object_pool_wrapper().FindNativeEntry(&label, kNotPatchable);
  const intptr_t argc_tag_kidx =
      __ object_pool_wrapper().FindImmediate(static_cast<uword>(argc_tag));
  __ PushConstant(target_kidx);
  __ PushConstant(argc_tag_kidx);
  if (is_bootstrap_native()) {
    __ NativeBootstrapCall();
  } else {
    __ NativeCall();
  }
  compiler->RecordSafepoint(locs());
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, Thread::kNoDeoptId,
                                 token_pos());
}


EMIT_NATIVE_CODE(OneByteStringFromCharCode,
                 1,
                 Location::RequiresRegister(),
                 LocationSummary::kNoCall) {
  ASSERT(compiler->is_optimizing());
  const Register char_code = locs()->in(0).reg();  // Char code is a smi.
  const Register result = locs()->out(0).reg();
  __ OneByteStringFromCharCode(result, char_code);
}


EMIT_NATIVE_CODE(StringToCharCode,
                 1,
                 Location::RequiresRegister(),
                 LocationSummary::kNoCall) {
  ASSERT(cid_ == kOneByteStringCid);
  const Register str = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();  // Result char code is a smi.
  __ StringToCharCode(result, str);
}


EMIT_NATIVE_CODE(AllocateObject,
                 0,
                 Location::RequiresRegister(),
                 LocationSummary::kCall) {
  if (ArgumentCount() == 1) {
    // Allocate with type arguments.
    if (compiler->is_optimizing()) {
      // If we're optimizing, try a streamlined fastpath.
      const intptr_t instance_size = cls().instance_size();
      Isolate* isolate = Isolate::Current();
      if (Heap::IsAllocatableInNewSpace(instance_size) &&
          !cls().TraceAllocation(isolate)) {
        uword tags = 0;
        tags = RawObject::SizeTag::update(instance_size, tags);
        ASSERT(cls().id() != kIllegalCid);
        tags = RawObject::ClassIdTag::update(cls().id(), tags);
        if (Smi::IsValid(tags)) {
          const intptr_t tags_kidx =
              __ AddConstant(Smi::Handle(Smi::New(tags)));
          __ AllocateTOpt(locs()->out(0).reg(), tags_kidx);
          __ Nop(cls().type_arguments_field_offset());
        }
      }
      __ PushConstant(cls());
      __ AllocateT();
      compiler->AddCurrentDescriptor(RawPcDescriptors::kOther,
                                     Thread::kNoDeoptId, token_pos());
      compiler->RecordSafepoint(locs());
      __ PopLocal(locs()->out(0).reg());
    } else {
      __ PushConstant(cls());
      __ AllocateT();
      compiler->AddCurrentDescriptor(RawPcDescriptors::kOther,
                                     Thread::kNoDeoptId, token_pos());
      compiler->RecordSafepoint(locs());
    }
  } else if (compiler->is_optimizing()) {
    // If we're optimizing, try a streamlined fastpath.
    const intptr_t instance_size = cls().instance_size();
    Isolate* isolate = Isolate::Current();
    if (Heap::IsAllocatableInNewSpace(instance_size) &&
        !cls().TraceAllocation(isolate)) {
      uword tags = 0;
      tags = RawObject::SizeTag::update(instance_size, tags);
      ASSERT(cls().id() != kIllegalCid);
      tags = RawObject::ClassIdTag::update(cls().id(), tags);
      if (Smi::IsValid(tags)) {
        const intptr_t tags_kidx = __ AddConstant(Smi::Handle(Smi::New(tags)));
        __ AllocateOpt(locs()->out(0).reg(), tags_kidx);
      }
    }
    const intptr_t kidx = __ AddConstant(cls());
    __ Allocate(kidx);
    compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, Thread::kNoDeoptId,
                                   token_pos());
    compiler->RecordSafepoint(locs());
    __ PopLocal(locs()->out(0).reg());
  } else {
    const intptr_t kidx = __ AddConstant(cls());
    __ Allocate(kidx);
    compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, Thread::kNoDeoptId,
                                   token_pos());
    compiler->RecordSafepoint(locs());
  }
}


EMIT_NATIVE_CODE(StoreInstanceField, 2) {
  ASSERT(!HasTemp());
  ASSERT(offset_in_bytes() % kWordSize == 0);
  if (compiler->is_optimizing()) {
    const Register value = locs()->in(1).reg();
    const Register instance = locs()->in(0).reg();
    if (Utils::IsInt(8, offset_in_bytes() / kWordSize)) {
      __ StoreField(instance, offset_in_bytes() / kWordSize, value);
    } else {
      __ StoreFieldExt(instance, value);
      __ Nop(offset_in_bytes() / kWordSize);
    }
  } else {
    __ StoreFieldTOS(offset_in_bytes() / kWordSize);
  }
}


EMIT_NATIVE_CODE(LoadField, 1, Location::RequiresRegister()) {
  ASSERT(offset_in_bytes() % kWordSize == 0);
  if (compiler->is_optimizing()) {
    const Register result = locs()->out(0).reg();
    const Register instance = locs()->in(0).reg();
    if (Utils::IsInt(8, offset_in_bytes() / kWordSize)) {
      __ LoadField(result, instance, offset_in_bytes() / kWordSize);
    } else {
      __ LoadFieldExt(result, instance);
      __ Nop(offset_in_bytes() / kWordSize);
    }
  } else {
    __ LoadFieldTOS(offset_in_bytes() / kWordSize);
  }
}


EMIT_NATIVE_CODE(LoadUntagged, 1, Location::RequiresRegister()) {
  const Register obj = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();
  if (object()->definition()->representation() == kUntagged) {
    __ LoadUntagged(result, obj, offset() / kWordSize);
  } else {
    ASSERT(object()->definition()->representation() == kTagged);
    __ LoadField(result, obj, offset() / kWordSize);
  }
}


EMIT_NATIVE_CODE(BooleanNegate, 1, Location::RequiresRegister()) {
  if (compiler->is_optimizing()) {
    __ BooleanNegate(locs()->out(0).reg(), locs()->in(0).reg());
  } else {
    __ BooleanNegateTOS();
  }
}


EMIT_NATIVE_CODE(AllocateContext,
                 0,
                 Location::RequiresRegister(),
                 LocationSummary::kCall) {
  ASSERT(!compiler->is_optimizing());
  __ AllocateContext(num_context_variables());
  compiler->RecordSafepoint(locs());
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, Thread::kNoDeoptId,
                                 token_pos());
}


EMIT_NATIVE_CODE(AllocateUninitializedContext,
                 0,
                 Location::RequiresRegister(),
                 LocationSummary::kCall) {
  ASSERT(compiler->is_optimizing());
  __ AllocateUninitializedContext(locs()->out(0).reg(),
                                  num_context_variables());
  __ AllocateContext(num_context_variables());
  compiler->RecordSafepoint(locs());
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, Thread::kNoDeoptId,
                                 token_pos());
  __ PopLocal(locs()->out(0).reg());
}


EMIT_NATIVE_CODE(CloneContext,
                 1,
                 Location::RequiresRegister(),
                 LocationSummary::kCall) {
  if (compiler->is_optimizing()) {
    __ Push(locs()->in(0).reg());
  }
  __ CloneContext();
  compiler->RecordSafepoint(locs());
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, Thread::kNoDeoptId,
                                 token_pos());
  if (compiler->is_optimizing()) {
    __ PopLocal(locs()->out(0).reg());
  }
}


EMIT_NATIVE_CODE(CatchBlockEntry, 0) {
  __ Bind(compiler->GetJumpLabel(this));
  compiler->AddExceptionHandler(catch_try_index(), try_index(),
                                compiler->assembler()->CodeSize(),
                                catch_handler_types_, needs_stacktrace());

  if (HasParallelMove()) {
    compiler->parallel_move_resolver()->EmitNativeCode(parallel_move());
  }
  if (compiler->is_optimizing()) {
    // In optimized code, variables at the catch block entry reside at the top
    // of the allocatable register range.
    const intptr_t num_non_copied_params =
        compiler->flow_graph().num_non_copied_params();
    const intptr_t exception_reg =
        kNumberOfCpuRegisters -
        (-exception_var().index() + num_non_copied_params);
    const intptr_t stacktrace_reg =
        kNumberOfCpuRegisters -
        (-stacktrace_var().index() + num_non_copied_params);
    __ MoveSpecial(exception_reg, Simulator::kExceptionSpecialIndex);
    __ MoveSpecial(stacktrace_reg, Simulator::kStacktraceSpecialIndex);
  } else {
    __ MoveSpecial(LocalVarIndex(0, exception_var().index()),
                   Simulator::kExceptionSpecialIndex);
    __ MoveSpecial(LocalVarIndex(0, stacktrace_var().index()),
                   Simulator::kStacktraceSpecialIndex);
  }
  __ SetFrame(compiler->StackSize());
}


EMIT_NATIVE_CODE(Throw, 0, Location::NoLocation(), LocationSummary::kCall) {
  __ Throw(0);
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, deopt_id(),
                                 token_pos());
  compiler->RecordAfterCall(this);
  __ Trap();
}


EMIT_NATIVE_CODE(ReThrow, 0, Location::NoLocation(), LocationSummary::kCall) {
  compiler->SetNeedsStacktrace(catch_try_index());
  __ Throw(1);
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, deopt_id(),
                                 token_pos());
  compiler->RecordAfterCall(this);
  __ Trap();
}

EMIT_NATIVE_CODE(InstantiateType,
                 1,
                 Location::RequiresRegister(),
                 LocationSummary::kCall) {
  if (compiler->is_optimizing()) {
    __ Push(locs()->in(0).reg());
  }
  __ InstantiateType(__ AddConstant(type()));
  compiler->RecordSafepoint(locs());
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, deopt_id(),
                                 token_pos());
  if (compiler->is_optimizing()) {
    __ PopLocal(locs()->out(0).reg());
  }
}

EMIT_NATIVE_CODE(InstantiateTypeArguments,
                 1,
                 Location::RequiresRegister(),
                 LocationSummary::kCall) {
  if (compiler->is_optimizing()) {
    __ Push(locs()->in(0).reg());
  }
  __ InstantiateTypeArgumentsTOS(
      type_arguments().IsRawInstantiatedRaw(type_arguments().Length()),
      __ AddConstant(type_arguments()));
  compiler->RecordSafepoint(locs());
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, deopt_id(),
                                 token_pos());
  if (compiler->is_optimizing()) {
    __ PopLocal(locs()->out(0).reg());
  }
}


void DebugStepCheckInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
  __ DebugStep();
  compiler->AddCurrentDescriptor(stub_kind_, Thread::kNoDeoptId, token_pos());
}


void GraphEntryInstr::EmitNativeCode(FlowGraphCompiler* compiler) {
  if (!compiler->CanFallThroughTo(normal_entry())) {
    __ Jump(compiler->GetJumpLabel(normal_entry()));
  }
}


LocationSummary* Instruction::MakeCallSummary(Zone* zone) {
  LocationSummary* result =
      new (zone) LocationSummary(zone, 0, 0, LocationSummary::kCall);
  // TODO(vegorov) support allocating out registers for calls.
  // Currently we require them to be fixed.
  result->set_out(0, Location::RegisterLocation(0));
  return result;
}


CompileType BinaryUint32OpInstr::ComputeType() const {
  return CompileType::Int();
}


CompileType ShiftUint32OpInstr::ComputeType() const {
  return CompileType::Int();
}


CompileType UnaryUint32OpInstr::ComputeType() const {
  return CompileType::Int();
}


static const intptr_t kMintShiftCountLimit = 63;


bool ShiftMintOpInstr::has_shift_count_check() const {
  return !RangeUtils::IsWithin(right()->definition()->range(), 0,
                               kMintShiftCountLimit);
}


CompileType LoadIndexedInstr::ComputeType() const {
  switch (class_id_) {
    case kArrayCid:
    case kImmutableArrayCid:
      return CompileType::Dynamic();

    case kTypedDataFloat32ArrayCid:
    case kTypedDataFloat64ArrayCid:
      return CompileType::FromCid(kDoubleCid);
    case kTypedDataFloat32x4ArrayCid:
      return CompileType::FromCid(kFloat32x4Cid);
    case kTypedDataInt32x4ArrayCid:
      return CompileType::FromCid(kInt32x4Cid);
    case kTypedDataFloat64x2ArrayCid:
      return CompileType::FromCid(kFloat64x2Cid);

    case kTypedDataInt8ArrayCid:
    case kTypedDataUint8ArrayCid:
    case kTypedDataUint8ClampedArrayCid:
    case kExternalTypedDataUint8ArrayCid:
    case kExternalTypedDataUint8ClampedArrayCid:
    case kTypedDataInt16ArrayCid:
    case kTypedDataUint16ArrayCid:
    case kOneByteStringCid:
    case kTwoByteStringCid:
    case kExternalOneByteStringCid:
    case kExternalTwoByteStringCid:
      return CompileType::FromCid(kSmiCid);

    case kTypedDataInt32ArrayCid:
    case kTypedDataUint32ArrayCid:
      return CompileType::Int();

    default:
      UNREACHABLE();
      return CompileType::Dynamic();
  }
}


Representation LoadIndexedInstr::representation() const {
  switch (class_id_) {
    case kArrayCid:
    case kImmutableArrayCid:
    case kTypedDataInt8ArrayCid:
    case kTypedDataUint8ArrayCid:
    case kTypedDataUint8ClampedArrayCid:
    case kExternalTypedDataUint8ArrayCid:
    case kExternalTypedDataUint8ClampedArrayCid:
    case kTypedDataInt16ArrayCid:
    case kTypedDataUint16ArrayCid:
    case kOneByteStringCid:
    case kTwoByteStringCid:
    case kExternalOneByteStringCid:
    case kExternalTwoByteStringCid:
      return kTagged;
    case kTypedDataInt32ArrayCid:
      return kUnboxedInt32;
    case kTypedDataUint32ArrayCid:
      return kUnboxedUint32;
    case kTypedDataFloat32ArrayCid:
    case kTypedDataFloat64ArrayCid:
      return kUnboxedDouble;
    case kTypedDataInt32x4ArrayCid:
      return kUnboxedInt32x4;
    case kTypedDataFloat32x4ArrayCid:
      return kUnboxedFloat32x4;
    case kTypedDataFloat64x2ArrayCid:
      return kUnboxedFloat64x2;
    default:
      UNREACHABLE();
      return kTagged;
  }
}


Representation StoreIndexedInstr::RequiredInputRepresentation(
    intptr_t idx) const {
  // Array can be a Dart object or a pointer to external data.
  if (idx == 0) {
    return kNoRepresentation;  // Flexible input representation.
  }
  if (idx == 1) {
    return kTagged;  // Index is a smi.
  }
  ASSERT(idx == 2);
  switch (class_id_) {
    case kArrayCid:
    case kOneByteStringCid:
    case kTwoByteStringCid:
    case kExternalOneByteStringCid:
    case kExternalTwoByteStringCid:
    case kTypedDataInt8ArrayCid:
    case kTypedDataUint8ArrayCid:
    case kExternalTypedDataUint8ArrayCid:
    case kTypedDataUint8ClampedArrayCid:
    case kExternalTypedDataUint8ClampedArrayCid:
    case kTypedDataInt16ArrayCid:
    case kTypedDataUint16ArrayCid:
      return kTagged;
    case kTypedDataInt32ArrayCid:
      return kUnboxedInt32;
    case kTypedDataUint32ArrayCid:
      return kUnboxedUint32;
    case kTypedDataFloat32ArrayCid:
    case kTypedDataFloat64ArrayCid:
      return kUnboxedDouble;
    case kTypedDataFloat32x4ArrayCid:
      return kUnboxedFloat32x4;
    case kTypedDataInt32x4ArrayCid:
      return kUnboxedInt32x4;
    case kTypedDataFloat64x2ArrayCid:
      return kUnboxedFloat64x2;
    default:
      UNREACHABLE();
      return kTagged;
  }
}


void Environment::DropArguments(intptr_t argc) {
#if defined(DEBUG)
  // Check that we are in the backend - register allocation has been run.
  ASSERT(locations_ != NULL);

  // Check that we are only dropping a valid number of instructions from the
  // environment.
  ASSERT(argc <= values_.length());
#endif
  values_.TruncateTo(values_.length() - argc);
}


EMIT_NATIVE_CODE(CheckSmi, 1) {
  __ CheckSmi(locs()->in(0).reg());
  compiler->EmitDeopt(deopt_id(), ICData::kDeoptCheckSmi,
                      licm_hoisted_ ? ICData::kHoisted : 0);
}


EMIT_NATIVE_CODE(CheckEitherNonSmi, 2) {
  const Register left = locs()->in(0).reg();
  const Register right = locs()->in(1).reg();
  __ CheckEitherNonSmi(left, right);
  compiler->EmitDeopt(deopt_id(), ICData::kDeoptBinaryDoubleOp,
                      licm_hoisted_ ? ICData::kHoisted : 0);
}


EMIT_NATIVE_CODE(CheckClassId, 1) {
  __ CheckClassId(locs()->in(0).reg(), compiler->ToEmbeddableCid(cid_, this));
  compiler->EmitDeopt(deopt_id(), ICData::kDeoptCheckClass);
}


EMIT_NATIVE_CODE(CheckClass, 1) {
  const Register value = locs()->in(0).reg();
  if (IsNullCheck()) {
    ASSERT(DeoptIfNull() || DeoptIfNotNull());
    if (DeoptIfNull()) {
      __ IfEqNull(value);
    } else {
      __ IfNeNull(value);
    }
  } else {
    ASSERT((unary_checks().GetReceiverClassIdAt(0) != kSmiCid) ||
           (unary_checks().NumberOfChecks() > 1));
    const intptr_t may_be_smi =
        (unary_checks().GetReceiverClassIdAt(0) == kSmiCid) ? 1 : 0;
    bool is_dense_switch = false;
    intptr_t cid_mask = 0;
    if (IsDenseSwitch()) {
      ASSERT(cids_[0] < cids_[cids_.length() - 1]);
      cid_mask = ComputeCidMask();
      is_dense_switch = Smi::IsValid(cid_mask);
    }
    if (is_dense_switch) {
      const intptr_t low_cid = cids_[0];
      __ CheckDenseSwitch(value, may_be_smi);
      __ Nop(compiler->ToEmbeddableCid(low_cid, this));
      __ Nop(__ AddConstant(Smi::Handle(Smi::New(cid_mask))));
    } else {
      GrowableArray<CidTarget> sorted_ic_data;
      FlowGraphCompiler::SortICDataByCount(unary_checks(), &sorted_ic_data,
                                           /* drop_smi = */ true);
      const intptr_t sorted_length = sorted_ic_data.length();
      if (!Utils::IsUint(8, sorted_length)) {
        Unsupported(compiler);
        UNREACHABLE();
      }
      __ CheckCids(value, may_be_smi, sorted_length);
      for (intptr_t i = 0; i < sorted_length; i++) {
        __ Nop(compiler->ToEmbeddableCid(sorted_ic_data[i].cid, this));
      }
    }
  }
  compiler->EmitDeopt(deopt_id(), ICData::kDeoptCheckClass,
                      licm_hoisted_ ? ICData::kHoisted : 0);
}


EMIT_NATIVE_CODE(BinarySmiOp, 2, Location::RequiresRegister()) {
  const Register left = locs()->in(0).reg();
  const Register right = locs()->in(1).reg();
  const Register out = locs()->out(0).reg();
  const bool can_deopt = CanDeoptimize();
  bool needs_nop = false;
  switch (op_kind()) {
    case Token::kADD:
      __ Add(out, left, right);
      needs_nop = true;
      break;
    case Token::kSUB:
      __ Sub(out, left, right);
      needs_nop = true;
      break;
    case Token::kMUL:
      __ Mul(out, left, right);
      needs_nop = true;
      break;
    case Token::kTRUNCDIV:
      ASSERT(can_deopt);
      __ Div(out, left, right);
      break;
    case Token::kBIT_AND:
      ASSERT(!can_deopt);
      __ BitAnd(out, left, right);
      break;
    case Token::kBIT_OR:
      ASSERT(!can_deopt);
      __ BitOr(out, left, right);
      break;
    case Token::kBIT_XOR:
      ASSERT(!can_deopt);
      __ BitXor(out, left, right);
      break;
    case Token::kMOD:
      __ Mod(out, left, right);
      needs_nop = true;
      break;
    case Token::kSHR:
      __ Shr(out, left, right);
      needs_nop = true;
      break;
    case Token::kSHL:
      __ Shl(out, left, right);
      needs_nop = true;
      break;
    default:
      UNREACHABLE();
  }
  if (can_deopt) {
    compiler->EmitDeopt(deopt_id(), ICData::kDeoptBinarySmiOp);
  } else if (needs_nop) {
    __ Nop(0);
  }
}


EMIT_NATIVE_CODE(UnarySmiOp, 1, Location::RequiresRegister()) {
  switch (op_kind()) {
    case Token::kNEGATE: {
      __ Neg(locs()->out(0).reg(), locs()->in(0).reg());
      compiler->EmitDeopt(deopt_id(), ICData::kDeoptUnaryOp);
      break;
    }
    case Token::kBIT_NOT:
      __ BitNot(locs()->out(0).reg(), locs()->in(0).reg());
      break;
    default:
      UNREACHABLE();
      break;
  }
}


EMIT_NATIVE_CODE(Box, 1, Location::RequiresRegister(), LocationSummary::kCall) {
  ASSERT(from_representation() == kUnboxedDouble);
  const Register value = locs()->in(0).reg();
  const Register out = locs()->out(0).reg();
  const intptr_t instance_size = compiler->double_class().instance_size();
  Isolate* isolate = Isolate::Current();
  ASSERT(Heap::IsAllocatableInNewSpace(instance_size));
  if (!compiler->double_class().TraceAllocation(isolate)) {
    uword tags = 0;
    tags = RawObject::SizeTag::update(instance_size, tags);
    tags = RawObject::ClassIdTag::update(compiler->double_class().id(), tags);
    if (Smi::IsValid(tags)) {
      const intptr_t tags_kidx = __ AddConstant(Smi::Handle(Smi::New(tags)));
      __ AllocateOpt(out, tags_kidx);
    }
  }
  const intptr_t kidx = __ AddConstant(compiler->double_class());
  __ Allocate(kidx);
  compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, Thread::kNoDeoptId,
                                 token_pos());
  compiler->RecordSafepoint(locs());
  __ PopLocal(out);
  __ WriteIntoDouble(out, value);
}


EMIT_NATIVE_CODE(Unbox, 1, Location::RequiresRegister()) {
  ASSERT(representation() == kUnboxedDouble);
  const intptr_t value_cid = value()->Type()->ToCid();
  const intptr_t box_cid = BoxCid();
  const Register box = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();
  if (value_cid == box_cid) {
    __ UnboxDouble(result, box);
  } else if (CanConvertSmi() && (value_cid == kSmiCid)) {
    __ SmiToDouble(result, box);
  } else if ((value()->Type()->ToNullableCid() == box_cid) &&
             value()->Type()->is_nullable()) {
    __ IfEqNull(box);
    compiler->EmitDeopt(GetDeoptId(), ICData::kDeoptCheckClass);
    __ UnboxDouble(result, box);
  } else {
    __ CheckedUnboxDouble(result, box);
    compiler->EmitDeopt(GetDeoptId(), ICData::kDeoptCheckClass);
  }
}


EMIT_NATIVE_CODE(UnboxInteger32, 1, Location::RequiresRegister()) {
#if defined(ARCH_IS_64_BIT)
  const Register out = locs()->out(0).reg();
  const Register value = locs()->in(0).reg();
  const bool may_truncate = is_truncating() || !CanDeoptimize();
  __ UnboxInt32(out, value, may_truncate);
  if (CanDeoptimize()) {
    compiler->EmitDeopt(GetDeoptId(), ICData::kDeoptUnboxInteger);
  } else {
    __ Nop(0);
  }
#else
  Unsupported(compiler);
  UNREACHABLE();
#endif  // defined(ARCH_IS_64_BIT)
}


EMIT_NATIVE_CODE(BoxInteger32, 1, Location::RequiresRegister()) {
#if defined(ARCH_IS_64_BIT)
  const Register out = locs()->out(0).reg();
  const Register value = locs()->in(0).reg();
  if (from_representation() == kUnboxedInt32) {
    __ BoxInt32(out, value);
  } else {
    ASSERT(from_representation() == kUnboxedUint32);
    __ BoxUint32(out, value);
  }
#else
  Unsupported(compiler);
  UNREACHABLE();
#endif  // defined(ARCH_IS_64_BIT)
}


EMIT_NATIVE_CODE(DoubleToSmi, 1, Location::RequiresRegister()) {
  const Register value = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();
  __ DoubleToSmi(result, value);
  compiler->EmitDeopt(deopt_id(), ICData::kDeoptDoubleToSmi);
}


EMIT_NATIVE_CODE(SmiToDouble, 1, Location::RequiresRegister()) {
  const Register value = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();
  __ SmiToDouble(result, value);
}


EMIT_NATIVE_CODE(BinaryDoubleOp, 2, Location::RequiresRegister()) {
  const Register left = locs()->in(0).reg();
  const Register right = locs()->in(1).reg();
  const Register result = locs()->out(0).reg();
  switch (op_kind()) {
    case Token::kADD:
      __ DAdd(result, left, right);
      break;
    case Token::kSUB:
      __ DSub(result, left, right);
      break;
    case Token::kMUL:
      __ DMul(result, left, right);
      break;
    case Token::kDIV:
      __ DDiv(result, left, right);
      break;
    default:
      UNREACHABLE();
  }
}


Condition DoubleTestOpInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
                                                BranchLabels labels) {
  UNREACHABLE();
  return Condition();
}


void DoubleTestOpInstr::EmitBranchCode(FlowGraphCompiler* compiler,
                                       BranchInstr* branch) {
  ASSERT(compiler->is_optimizing());
  BranchLabels labels = compiler->CreateBranchLabels(branch);
  const Register value = locs()->in(0).reg();
  switch (op_kind()) {
    case MethodRecognizer::kDouble_getIsNaN:
      __ DoubleIsNaN(value);
      break;
    case MethodRecognizer::kDouble_getIsInfinite:
      __ DoubleIsInfinite(value);
      break;
    default:
      UNREACHABLE();
  }
  const bool is_negated = kind() != Token::kEQ;
  EmitBranchOnCondition(compiler, is_negated ? NEXT_IS_FALSE : NEXT_IS_TRUE,
                        labels);
}


EMIT_NATIVE_CODE(DoubleTestOp, 1, Location::RequiresRegister()) {
  ASSERT(compiler->is_optimizing());
  const Register value = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();
  const bool is_negated = kind() != Token::kEQ;
  __ LoadConstant(result, is_negated ? Bool::True() : Bool::False());
  switch (op_kind()) {
    case MethodRecognizer::kDouble_getIsNaN:
      __ DoubleIsNaN(value);
      break;
    case MethodRecognizer::kDouble_getIsInfinite:
      __ DoubleIsInfinite(value);
      break;
    default:
      UNREACHABLE();
  }
  __ LoadConstant(result, is_negated ? Bool::False() : Bool::True());
}


EMIT_NATIVE_CODE(UnaryDoubleOp, 1, Location::RequiresRegister()) {
  const Register value = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();
  __ DNeg(result, value);
}


EMIT_NATIVE_CODE(MathUnary, 1, Location::RequiresRegister()) {
  const Register value = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();
  if (kind() == MathUnaryInstr::kSqrt) {
    __ DSqrt(result, value);
  } else if (kind() == MathUnaryInstr::kDoubleSquare) {
    __ DMul(result, value, value);
  } else {
    Unsupported(compiler);
    UNREACHABLE();
  }
}


EMIT_NATIVE_CODE(DoubleToDouble, 1, Location::RequiresRegister()) {
  const Register in = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();
  switch (recognized_kind()) {
    case MethodRecognizer::kDoubleTruncate:
      __ DTruncate(result, in);
      break;
    case MethodRecognizer::kDoubleFloor:
      __ DFloor(result, in);
      break;
    case MethodRecognizer::kDoubleCeil:
      __ DCeil(result, in);
      break;
    default:
      UNREACHABLE();
  }
}


EMIT_NATIVE_CODE(DoubleToFloat, 1, Location::RequiresRegister()) {
  const Register in = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();
  __ DoubleToFloat(result, in);
}


EMIT_NATIVE_CODE(FloatToDouble, 1, Location::RequiresRegister()) {
  const Register in = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();
  __ FloatToDouble(result, in);
}


EMIT_NATIVE_CODE(InvokeMathCFunction,
                 InputCount(),
                 Location::RequiresRegister()) {
  const Register left = locs()->in(0).reg();
  const Register result = locs()->out(0).reg();
  if (recognized_kind() == MethodRecognizer::kMathDoublePow) {
    const Register right = locs()->in(1).reg();
    __ DPow(result, left, right);
  } else if (recognized_kind() == MethodRecognizer::kDoubleMod) {
    const Register right = locs()->in(1).reg();
    __ DMod(result, left, right);
  } else if (recognized_kind() == MethodRecognizer::kMathSin) {
    __ DSin(result, left);
  } else if (recognized_kind() == MethodRecognizer::kMathCos) {
    __ DCos(result, left);
  } else {
    Unsupported(compiler);
    UNREACHABLE();
  }
}


EMIT_NATIVE_CODE(MathMinMax, 2, Location::RequiresRegister()) {
  ASSERT((op_kind() == MethodRecognizer::kMathMin) ||
         (op_kind() == MethodRecognizer::kMathMax));
  const Register left = locs()->in(0).reg();
  const Register right = locs()->in(1).reg();
  const Register result = locs()->out(0).reg();
  if (result_cid() == kDoubleCid) {
    if (op_kind() == MethodRecognizer::kMathMin) {
      __ DMin(result, left, right);
    } else {
      __ DMax(result, left, right);
    }
  } else {
    ASSERT(result_cid() == kSmiCid);
    if (op_kind() == MethodRecognizer::kMathMin) {
      __ Min(result, left, right);
    } else {
      __ Max(result, left, right);
    }
  }
}


static Token::Kind FlipCondition(Token::Kind kind) {
  switch (kind) {
    case Token::kEQ:
      return Token::kNE;
    case Token::kNE:
      return Token::kEQ;
    case Token::kLT:
      return Token::kGTE;
    case Token::kGT:
      return Token::kLTE;
    case Token::kLTE:
      return Token::kGT;
    case Token::kGTE:
      return Token::kLT;
    default:
      UNREACHABLE();
      return Token::kNE;
  }
}


static Bytecode::Opcode OpcodeForSmiCondition(Token::Kind kind) {
  switch (kind) {
    case Token::kEQ:
      return Bytecode::kIfEqStrict;
    case Token::kNE:
      return Bytecode::kIfNeStrict;
    case Token::kLT:
      return Bytecode::kIfLt;
    case Token::kGT:
      return Bytecode::kIfGt;
    case Token::kLTE:
      return Bytecode::kIfLe;
    case Token::kGTE:
      return Bytecode::kIfGe;
    default:
      UNREACHABLE();
      return Bytecode::kTrap;
  }
}


static Bytecode::Opcode OpcodeForDoubleCondition(Token::Kind kind) {
  switch (kind) {
    case Token::kEQ:
      return Bytecode::kIfDEq;
    case Token::kNE:
      return Bytecode::kIfDNe;
    case Token::kLT:
      return Bytecode::kIfDLt;
    case Token::kGT:
      return Bytecode::kIfDGt;
    case Token::kLTE:
      return Bytecode::kIfDLe;
    case Token::kGTE:
      return Bytecode::kIfDGe;
    default:
      UNREACHABLE();
      return Bytecode::kTrap;
  }
}


static Condition EmitSmiComparisonOp(FlowGraphCompiler* compiler,
                                     LocationSummary* locs,
                                     Token::Kind kind,
                                     BranchLabels labels) {
  const Register left = locs->in(0).reg();
  const Register right = locs->in(1).reg();
  Token::Kind comparison = kind;
  Condition condition = NEXT_IS_TRUE;
  if (labels.fall_through != labels.false_label) {
    // If we aren't falling through to the false label, we can save a Jump
    // instruction in the case that the true case is the fall through by
    // flipping the sense of the test such that the instruction following the
    // test is the Jump to the false label.
    condition = NEXT_IS_FALSE;
    comparison = FlipCondition(kind);
  }
  __ Emit(Bytecode::Encode(OpcodeForSmiCondition(comparison), left, right));
  return condition;
}


static Condition EmitDoubleComparisonOp(FlowGraphCompiler* compiler,
                                        LocationSummary* locs,
                                        Token::Kind kind) {
  const Register left = locs->in(0).reg();
  const Register right = locs->in(1).reg();
  Token::Kind comparison = kind;
  // For double comparisons we can't flip the condition like with smi
  // comparisons because of NaN which will compare false for all except !=
  // operations.
  // TODO(fschneider): Change the block order instead in DBC so that the
  // false block in always the fall-through block.
  Condition condition = NEXT_IS_TRUE;
  __ Emit(Bytecode::Encode(OpcodeForDoubleCondition(comparison), left, right));
  return condition;
}


Condition EqualityCompareInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
                                                   BranchLabels labels) {
  if (operation_cid() == kSmiCid) {
    return EmitSmiComparisonOp(compiler, locs(), kind(), labels);
  } else {
    ASSERT(operation_cid() == kDoubleCid);
    return EmitDoubleComparisonOp(compiler, locs(), kind());
  }
}


EMIT_NATIVE_CODE(EqualityCompare, 2, Location::RequiresRegister()) {
  ASSERT(compiler->is_optimizing());
  ASSERT((kind() == Token::kEQ) || (kind() == Token::kNE));
  Label is_true, is_false;
  // These labels are not used. They are arranged so that EmitComparisonCode
  // emits a test that executes the following instruction when the test
  // succeeds.
  BranchLabels labels = {&is_true, &is_false, &is_false};
  const Register result = locs()->out(0).reg();
  __ LoadConstant(result, Bool::False());
  Condition true_condition = EmitComparisonCode(compiler, labels);
  ASSERT(true_condition == NEXT_IS_TRUE);
  __ LoadConstant(result, Bool::True());
}


void EqualityCompareInstr::EmitBranchCode(FlowGraphCompiler* compiler,
                                          BranchInstr* branch) {
  ASSERT((kind() == Token::kNE) || (kind() == Token::kEQ));
  BranchLabels labels = compiler->CreateBranchLabels(branch);
  Condition true_condition = EmitComparisonCode(compiler, labels);
  EmitBranchOnCondition(compiler, true_condition, labels);
}


Condition RelationalOpInstr::EmitComparisonCode(FlowGraphCompiler* compiler,
                                                BranchLabels labels) {
  if (operation_cid() == kSmiCid) {
    return EmitSmiComparisonOp(compiler, locs(), kind(), labels);
  } else {
    ASSERT(operation_cid() == kDoubleCid);
    return EmitDoubleComparisonOp(compiler, locs(), kind());
  }
}


EMIT_NATIVE_CODE(RelationalOp, 2, Location::RequiresRegister()) {
  ASSERT(compiler->is_optimizing());
  Label is_true, is_false;
  BranchLabels labels = {&is_true, &is_false, &is_false};
  const Register result = locs()->out(0).reg();
  __ LoadConstant(result, Bool::False());
  Condition true_condition = EmitComparisonCode(compiler, labels);
  ASSERT(true_condition == NEXT_IS_TRUE);
  __ LoadConstant(result, Bool::True());
}


void RelationalOpInstr::EmitBranchCode(FlowGraphCompiler* compiler,
                                       BranchInstr* branch) {
  BranchLabels labels = compiler->CreateBranchLabels(branch);
  Condition true_condition = EmitComparisonCode(compiler, labels);
  EmitBranchOnCondition(compiler, true_condition, labels);
}


EMIT_NATIVE_CODE(CheckArrayBound, 2) {
  const Register length = locs()->in(kLengthPos).reg();
  const Register index = locs()->in(kIndexPos).reg();
  const intptr_t index_cid = this->index()->Type()->ToCid();
  if (index_cid != kSmiCid) {
    __ CheckSmi(index);
    compiler->EmitDeopt(deopt_id(), ICData::kDeoptCheckArrayBound,
                        (generalized_ ? ICData::kGeneralized : 0) |
                            (licm_hoisted_ ? ICData::kHoisted : 0));
  }
  __ IfULe(length, index);
  compiler->EmitDeopt(deopt_id(), ICData::kDeoptCheckArrayBound,
                      (generalized_ ? ICData::kGeneralized : 0) |
                          (licm_hoisted_ ? ICData::kHoisted : 0));
}

}  // namespace dart

#endif  // defined TARGET_ARCH_DBC