Move ConstantPropagator from flow_graph_optimizer.cc/.h into separate files.

runtime/vm/constant_propagator.cc

Index: runtime/vm/constant_propagator.cc
===================================================================
--- runtime/vm/constant_propagator.cc	(revision 42566)
+++ runtime/vm/constant_propagator.cc	(working copy)
@@ -2,7504 +2,27 @@
 // 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/flow_graph_optimizer.h"
+#include "vm/constant_propagator.h"
 
 #include "vm/bit_vector.h"
-#include "vm/cha.h"
-#include "vm/cpu.h"
-#include "vm/dart_entry.h"
-#include "vm/exceptions.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
 #include "vm/flow_graph_range_analysis.h"
-#include "vm/hash_map.h"
 #include "vm/il_printer.h"
 #include "vm/intermediate_language.h"
-#include "vm/object_store.h"
 #include "vm/parser.h"
-#include "vm/resolver.h"
-#include "vm/scopes.h"
-#include "vm/stack_frame.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
-DEFINE_FLAG(int, getter_setter_ratio, 13,
-    "Ratio of getter/setter usage used for double field unboxing heuristics");
-DEFINE_FLAG(bool, load_cse, true, "Use redundant load elimination.");
-DEFINE_FLAG(bool, dead_store_elimination, true, "Eliminate dead stores");
-DEFINE_FLAG(int, max_polymorphic_checks, 4,
-    "Maximum number of polymorphic check, otherwise it is megamorphic.");
-DEFINE_FLAG(int, max_equality_polymorphic_checks, 32,
-    "Maximum number of polymorphic checks in equality operator,"
-    " otherwise use megamorphic dispatch.");
 DEFINE_FLAG(bool, remove_redundant_phis, true, "Remove redundant phis.");
 DEFINE_FLAG(bool, trace_constant_propagation, false,
     "Print constant propagation and useless code elimination.");
-DEFINE_FLAG(bool, trace_load_optimization, false,
-    "Print live sets for load optimization pass.");
-DEFINE_FLAG(bool, trace_optimization, false, "Print optimization details.");
-DEFINE_FLAG(bool, truncating_left_shift, true,
-    "Optimize left shift to truncate if possible");
-DEFINE_FLAG(bool, use_cha, true, "Use class hierarchy analysis.");
-#if defined(TARGET_ARCH_ARM) || defined(TARGET_ARCH_IA32)
-DEFINE_FLAG(bool, trace_smi_widening, false, "Trace Smi->Int32 widening pass.");
-#endif
-DECLARE_FLAG(bool, enable_type_checks);
-DECLARE_FLAG(bool, source_lines);
-DECLARE_FLAG(bool, trace_type_check_elimination);
-DECLARE_FLAG(bool, warn_on_javascript_compatibility);
 
 // Quick access to the locally defined isolate() method.
 #define I (isolate())
 
-static bool ShouldInlineSimd() {
-  return FlowGraphCompiler::SupportsUnboxedSimd128();
-}
 
-
-static bool CanUnboxDouble() {
-  return FlowGraphCompiler::SupportsUnboxedDoubles();
-}
-
-
-static bool ShouldInlineInt64ArrayOps() {
-#if defined(TARGET_ARCH_X64)
-  return true;
-#endif
-  return false;
-}
-
-static bool CanConvertUnboxedMintToDouble() {
-#if defined(TARGET_ARCH_IA32)
-  return true;
-#else
-  // ARM does not have a short instruction sequence for converting int64 to
-  // double.
-  // TODO(johnmccutchan): Investigate possibility on MIPS once
-  // mints are implemented there.
-  return false;
-#endif
-}
-
-
-// Optimize instance calls using ICData.
-void FlowGraphOptimizer::ApplyICData() {
-  VisitBlocks();
-}
-
-
-// Optimize instance calls using cid.  This is called after optimizer
-// converted instance calls to instructions. Any remaining
-// instance calls are either megamorphic calls, cannot be optimized or
-// have no runtime type feedback collected.
-// Attempts to convert an instance call (IC call) using propagated class-ids,
-// e.g., receiver class id, guarded-cid, or by guessing cid-s.
-void FlowGraphOptimizer::ApplyClassIds() {
-  ASSERT(current_iterator_ == NULL);
-  for (intptr_t i = 0; i < block_order_.length(); ++i) {
-    BlockEntryInstr* entry = block_order_[i];
-    ForwardInstructionIterator it(entry);
-    current_iterator_ = &it;
-    for (; !it.Done(); it.Advance()) {
-      Instruction* instr = it.Current();
-      if (instr->IsInstanceCall()) {
-        InstanceCallInstr* call = instr->AsInstanceCall();
-        if (call->HasICData()) {
-          if (TryCreateICData(call)) {
-            VisitInstanceCall(call);
-          }
-        }
-      } else if (instr->IsPolymorphicInstanceCall()) {
-        SpecializePolymorphicInstanceCall(instr->AsPolymorphicInstanceCall());
-      } else if (instr->IsStrictCompare()) {
-        VisitStrictCompare(instr->AsStrictCompare());
-      } else if (instr->IsBranch()) {
-        ComparisonInstr* compare = instr->AsBranch()->comparison();
-        if (compare->IsStrictCompare()) {
-          VisitStrictCompare(compare->AsStrictCompare());
-        }
-      }
-    }
-    current_iterator_ = NULL;
-  }
-}
-
-
-// TODO(srdjan): Test/support other number types as well.
-static bool IsNumberCid(intptr_t cid) {
-  return (cid == kSmiCid) || (cid == kDoubleCid);
-}
-
-
-// Attempt to build ICData for call using propagated class-ids.
-bool FlowGraphOptimizer::TryCreateICData(InstanceCallInstr* call) {
-  ASSERT(call->HasICData());
-  if (call->ic_data()->NumberOfUsedChecks() > 0) {
-    // This occurs when an instance call has too many checks, will be converted
-    // to megamorphic call.
-    return false;
-  }
-  if (FLAG_warn_on_javascript_compatibility) {
-    // Do not make the instance call megamorphic if the callee needs to decode
-    // the calling code sequence to lookup the ic data and verify if a warning
-    // has already been issued or not.
-    // TryCreateICData is only invoked if the ic_data target has not been called
-    // yet, so no warning can possibly have been issued.
-    ASSERT(!call->ic_data()->IssuedJSWarning());
-    if (call->ic_data()->MayCheckForJSWarning()) {
-      return false;
-    }
-  }
-  GrowableArray<intptr_t> class_ids(call->ic_data()->NumArgsTested());
-  ASSERT(call->ic_data()->NumArgsTested() <= call->ArgumentCount());
-  for (intptr_t i = 0; i < call->ic_data()->NumArgsTested(); i++) {
-    const intptr_t cid = call->PushArgumentAt(i)->value()->Type()->ToCid();
-    class_ids.Add(cid);
-  }
-
-  const Token::Kind op_kind = call->token_kind();
-  if (Token::IsRelationalOperator(op_kind) ||
-      Token::IsEqualityOperator(op_kind) ||
-      Token::IsBinaryOperator(op_kind)) {
-    // Guess cid: if one of the inputs is a number assume that the other
-    // is a number of same type.
-    const intptr_t cid_0 = class_ids[0];
-    const intptr_t cid_1 = class_ids[1];
-    if ((cid_0 == kDynamicCid) && (IsNumberCid(cid_1))) {
-      class_ids[0] = cid_1;
-    } else if (IsNumberCid(cid_0) && (cid_1 == kDynamicCid)) {
-      class_ids[1] = cid_0;
-    }
-  }
-
-  for (intptr_t i = 0; i < class_ids.length(); i++) {
-    if (class_ids[i] == kDynamicCid) {
-      // Not all cid-s known.
-      return false;
-    }
-  }
-
-  const Array& args_desc_array = Array::Handle(I,
-      ArgumentsDescriptor::New(call->ArgumentCount(), call->argument_names()));
-  ArgumentsDescriptor args_desc(args_desc_array);
-  const Class& receiver_class = Class::Handle(I,
-      isolate()->class_table()->At(class_ids[0]));
-  const Function& function = Function::Handle(I,
-      Resolver::ResolveDynamicForReceiverClass(
-          receiver_class,
-          call->function_name(),
-          args_desc));
-  if (function.IsNull()) {
-    return false;
-  }
-  // Create new ICData, do not modify the one attached to the instruction
-  // since it is attached to the assembly instruction itself.
-  // TODO(srdjan): Prevent modification of ICData object that is
-  // referenced in assembly code.
-  ICData& ic_data = ICData::ZoneHandle(I, ICData::New(
-      flow_graph_->parsed_function()->function(),
-      call->function_name(),
-      args_desc_array,
-      call->deopt_id(),
-      class_ids.length()));
-  if (class_ids.length() > 1) {
-    ic_data.AddCheck(class_ids, function);
-  } else {
-    ASSERT(class_ids.length() == 1);
-    ic_data.AddReceiverCheck(class_ids[0], function);
-  }
-  call->set_ic_data(&ic_data);
-  return true;
-}
-
-
-const ICData& FlowGraphOptimizer::TrySpecializeICData(const ICData& ic_data,
-                                                      intptr_t cid) {
-  ASSERT(ic_data.NumArgsTested() == 1);
-
-  if ((ic_data.NumberOfUsedChecks() == 1) && ic_data.HasReceiverClassId(cid)) {
-    return ic_data;  // Nothing to do
-  }
-
-  const Function& function =
-      Function::Handle(I, ic_data.GetTargetForReceiverClassId(cid));
-  // TODO(fschneider): Try looking up the function on the class if it is
-  // not found in the ICData.
-  if (!function.IsNull()) {
-    const ICData& new_ic_data = ICData::ZoneHandle(I, ICData::New(
-        Function::Handle(I, ic_data.owner()),
-        String::Handle(I, ic_data.target_name()),
-        Object::empty_array(),  // Dummy argument descriptor.
-        ic_data.deopt_id(),
-        ic_data.NumArgsTested()));
-    new_ic_data.SetDeoptReasons(ic_data.DeoptReasons());
-    new_ic_data.AddReceiverCheck(cid, function);
-    return new_ic_data;
-  }
-
-  return ic_data;
-}
-
-
-void FlowGraphOptimizer::SpecializePolymorphicInstanceCall(
-    PolymorphicInstanceCallInstr* call) {
-  if (!call->with_checks()) {
-    return;  // Already specialized.
-  }
-
-  const intptr_t receiver_cid =
-      call->PushArgumentAt(0)->value()->Type()->ToCid();
-  if (receiver_cid == kDynamicCid) {
-    return;  // No information about receiver was infered.
-  }
-
-  const ICData& ic_data = TrySpecializeICData(call->ic_data(), receiver_cid);
-  if (ic_data.raw() == call->ic_data().raw()) {
-    // No specialization.
-    return;
-  }
-
-  const bool with_checks = false;
-  PolymorphicInstanceCallInstr* specialized =
-      new(I) PolymorphicInstanceCallInstr(call->instance_call(),
-                                          ic_data,
-                                          with_checks);
-  call->ReplaceWith(specialized, current_iterator());
-}
-
-
-static BinarySmiOpInstr* AsSmiShiftLeftInstruction(Definition* d) {
-  BinarySmiOpInstr* instr = d->AsBinarySmiOp();
-  if ((instr != NULL) && (instr->op_kind() == Token::kSHL)) {
-    return instr;
-  }
-  return NULL;
-}
-
-
-static bool IsPositiveOrZeroSmiConst(Definition* d) {
-  ConstantInstr* const_instr = d->AsConstant();
-  if ((const_instr != NULL) && (const_instr->value().IsSmi())) {
-    return Smi::Cast(const_instr->value()).Value() >= 0;
-  }
-  return false;
-}
-
-
-void FlowGraphOptimizer::OptimizeLeftShiftBitAndSmiOp(
-    Definition* bit_and_instr,
-    Definition* left_instr,
-    Definition* right_instr) {
-  ASSERT(bit_and_instr != NULL);
-  ASSERT((left_instr != NULL) && (right_instr != NULL));
-
-  // Check for pattern, smi_shift_left must be single-use.
-  bool is_positive_or_zero = IsPositiveOrZeroSmiConst(left_instr);
-  if (!is_positive_or_zero) {
-    is_positive_or_zero = IsPositiveOrZeroSmiConst(right_instr);
-  }
-  if (!is_positive_or_zero) return;
-
-  BinarySmiOpInstr* smi_shift_left = NULL;
-  if (bit_and_instr->InputAt(0)->IsSingleUse()) {
-    smi_shift_left = AsSmiShiftLeftInstruction(left_instr);
-  }
-  if ((smi_shift_left == NULL) && (bit_and_instr->InputAt(1)->IsSingleUse())) {
-    smi_shift_left = AsSmiShiftLeftInstruction(right_instr);
-  }
-  if (smi_shift_left == NULL) return;
-
-  // Pattern recognized.
-  smi_shift_left->mark_truncating();
-  ASSERT(bit_and_instr->IsBinarySmiOp() || bit_and_instr->IsBinaryMintOp());
-  if (bit_and_instr->IsBinaryMintOp()) {
-    // Replace Mint op with Smi op.
-    BinarySmiOpInstr* smi_op = new(I) BinarySmiOpInstr(
-        Token::kBIT_AND,
-        new(I) Value(left_instr),
-        new(I) Value(right_instr),
-        Isolate::kNoDeoptId);  // BIT_AND cannot deoptimize.
-    bit_and_instr->ReplaceWith(smi_op, current_iterator());
-  }
-}
-
-
-
-// Used by TryMergeDivMod.
-// Inserts a load-indexed instruction between a TRUNCDIV or MOD instruction,
-// and the using instruction. This is an intermediate step before merging.
-void FlowGraphOptimizer::AppendLoadIndexedForMerged(Definition* instr,
-                                                    intptr_t ix,
-                                                    intptr_t cid) {
-  const intptr_t index_scale = Instance::ElementSizeFor(cid);
-  ConstantInstr* index_instr =
-      flow_graph()->GetConstant(Smi::Handle(I, Smi::New(ix)));
-  LoadIndexedInstr* load =
-      new(I) LoadIndexedInstr(new(I) Value(instr),
-                                      new(I) Value(index_instr),
-                                      index_scale,
-                                      cid,
-                                      Isolate::kNoDeoptId,
-                                      instr->token_pos());
-  instr->ReplaceUsesWith(load);
-  flow_graph()->InsertAfter(instr, load, NULL, FlowGraph::kValue);
-}
-
-
-void FlowGraphOptimizer::AppendExtractNthOutputForMerged(Definition* instr,
-                                                         intptr_t index,
-                                                         Representation rep,
-                                                         intptr_t cid) {
-  ExtractNthOutputInstr* extract =
-      new(I) ExtractNthOutputInstr(new(I) Value(instr), index, rep, cid);
-  instr->ReplaceUsesWith(extract);
-  flow_graph()->InsertAfter(instr, extract, NULL, FlowGraph::kValue);
-}
-
-
-// Dart:
-//  var x = d % 10;
-//  var y = d ~/ 10;
-//  var z = x + y;
-//
-// IL:
-//  v4 <- %(v2, v3)
-//  v5 <- ~/(v2, v3)
-//  v6 <- +(v4, v5)
-//
-// IL optimized:
-//  v4 <- DIVMOD(v2, v3);
-//  v5 <- LoadIndexed(v4, 0); // ~/ result
-//  v6 <- LoadIndexed(v4, 1); // % result
-//  v7 <- +(v5, v6)
-// Because of the environment it is important that merged instruction replaces
-// first original instruction encountered.
-void FlowGraphOptimizer::TryMergeTruncDivMod(
-    GrowableArray<BinarySmiOpInstr*>* merge_candidates) {
-  if (merge_candidates->length() < 2) {
-    // Need at least a TRUNCDIV and a MOD.
-    return;
-  }
-  for (intptr_t i = 0; i < merge_candidates->length(); i++) {
-    BinarySmiOpInstr* curr_instr = (*merge_candidates)[i];
-    if (curr_instr == NULL) {
-      // Instruction was merged already.
-      continue;
-    }
-    ASSERT((curr_instr->op_kind() == Token::kTRUNCDIV) ||
-           (curr_instr->op_kind() == Token::kMOD));
-    // Check if there is kMOD/kTRUNDIV binop with same inputs.
-    const intptr_t other_kind = (curr_instr->op_kind() == Token::kTRUNCDIV) ?
-        Token::kMOD : Token::kTRUNCDIV;
-    Definition* left_def = curr_instr->left()->definition();
-    Definition* right_def = curr_instr->right()->definition();
-    for (intptr_t k = i + 1; k < merge_candidates->length(); k++) {
-      BinarySmiOpInstr* other_binop = (*merge_candidates)[k];
-      // 'other_binop' can be NULL if it was already merged.
-      if ((other_binop != NULL) &&
-          (other_binop->op_kind() == other_kind) &&
-          (other_binop->left()->definition() == left_def) &&
-          (other_binop->right()->definition() == right_def)) {
-        (*merge_candidates)[k] = NULL;  // Clear it.
-        ASSERT(curr_instr->HasUses());
-        AppendExtractNthOutputForMerged(
-            curr_instr,
-            MergedMathInstr::OutputIndexOf(curr_instr->op_kind()),
-            kTagged, kSmiCid);
-        ASSERT(other_binop->HasUses());
-        AppendExtractNthOutputForMerged(
-            other_binop,
-            MergedMathInstr::OutputIndexOf(other_binop->op_kind()),
-            kTagged, kSmiCid);
-
-        ZoneGrowableArray<Value*>* args = new(I) ZoneGrowableArray<Value*>(2);
-        args->Add(new(I) Value(curr_instr->left()->definition()));
-        args->Add(new(I) Value(curr_instr->right()->definition()));
-
-        // Replace with TruncDivMod.
-        MergedMathInstr* div_mod = new(I) MergedMathInstr(
-            args,
-            curr_instr->deopt_id(),
-            MergedMathInstr::kTruncDivMod);
-        curr_instr->ReplaceWith(div_mod, current_iterator());
-        other_binop->ReplaceUsesWith(div_mod);
-        other_binop->RemoveFromGraph();
-        // Only one merge possible. Because canonicalization happens later,
-        // more candidates are possible.
-        // TODO(srdjan): Allow merging of trunc-div/mod into truncDivMod.
-        break;
-      }
-    }
-  }
-}
-
-
-// Tries to merge MathUnary operations, in this case sinus and cosinus.
-void FlowGraphOptimizer::TryMergeMathUnary(
-    GrowableArray<MathUnaryInstr*>* merge_candidates) {
-  if (!FlowGraphCompiler::SupportsSinCos() || !CanUnboxDouble()) {
-    return;
-  }
-  if (merge_candidates->length() < 2) {
-    // Need at least a SIN and a COS.
-    return;
-  }
-  for (intptr_t i = 0; i < merge_candidates->length(); i++) {
-    MathUnaryInstr* curr_instr = (*merge_candidates)[i];
-    if (curr_instr == NULL) {
-      // Instruction was merged already.
-      continue;
-    }
-    const intptr_t kind = curr_instr->kind();
-    ASSERT((kind == MathUnaryInstr::kSin) ||
-           (kind == MathUnaryInstr::kCos));
-    // Check if there is sin/cos binop with same inputs.
-    const intptr_t other_kind = (kind == MethodRecognizer::kMathSin) ?
-        MethodRecognizer::kMathCos : MethodRecognizer::kMathSin;
-    Definition* def = curr_instr->value()->definition();
-    for (intptr_t k = i + 1; k < merge_candidates->length(); k++) {
-      MathUnaryInstr* other_op = (*merge_candidates)[k];
-      // 'other_op' can be NULL if it was already merged.
-      if ((other_op != NULL) && (other_op->kind() == other_kind) &&
-          (other_op->value()->definition() == def)) {
-        (*merge_candidates)[k] = NULL;  // Clear it.
-        ASSERT(curr_instr->HasUses());
-        AppendExtractNthOutputForMerged(curr_instr,
-                                        MergedMathInstr::OutputIndexOf(kind),
-                                        kUnboxedDouble, kDoubleCid);
-        ASSERT(other_op->HasUses());
-        AppendExtractNthOutputForMerged(
-            other_op,
-            MergedMathInstr::OutputIndexOf(other_kind),
-            kUnboxedDouble, kDoubleCid);
-        ZoneGrowableArray<Value*>* args = new(I) ZoneGrowableArray<Value*>(1);
-        args->Add(new(I) Value(curr_instr->value()->definition()));
-        // Replace with SinCos.
-        MergedMathInstr* sin_cos =
-            new(I) MergedMathInstr(args,
-                                   curr_instr->DeoptimizationTarget(),
-                                   MergedMathInstr::kSinCos);
-        curr_instr->ReplaceWith(sin_cos, current_iterator());
-        other_op->ReplaceUsesWith(sin_cos);
-        other_op->RemoveFromGraph();
-        // Only one merge possible. Because canonicalization happens later,
-        // more candidates are possible.
-        // TODO(srdjan): Allow merging of sin/cos into sincos.
-        break;
-      }
-    }
-  }
-}
-
-
-// Optimize (a << b) & c pattern: if c is a positive Smi or zero, then the
-// shift can be a truncating Smi shift-left and result is always Smi.
-// Merging occurs only per basic-block.
-void FlowGraphOptimizer::TryOptimizePatterns() {
-  if (!FLAG_truncating_left_shift) return;
-  ASSERT(current_iterator_ == NULL);
-  GrowableArray<BinarySmiOpInstr*> div_mod_merge;
-  GrowableArray<MathUnaryInstr*> sin_cos_merge;
-  for (intptr_t i = 0; i < block_order_.length(); ++i) {
-    // Merging only per basic-block.
-    div_mod_merge.Clear();
-    sin_cos_merge.Clear();
-    BlockEntryInstr* entry = block_order_[i];
-    ForwardInstructionIterator it(entry);
-    current_iterator_ = &it;
-    for (; !it.Done(); it.Advance()) {
-      if (it.Current()->IsBinarySmiOp()) {
-        BinarySmiOpInstr* binop = it.Current()->AsBinarySmiOp();
-        if (binop->op_kind() == Token::kBIT_AND) {
-          OptimizeLeftShiftBitAndSmiOp(binop,
-                                       binop->left()->definition(),
-                                       binop->right()->definition());
-        } else if ((binop->op_kind() == Token::kTRUNCDIV) ||
-                   (binop->op_kind() == Token::kMOD)) {
-          if (binop->HasUses()) {
-            div_mod_merge.Add(binop);
-          }
-        }
-      } else if (it.Current()->IsBinaryMintOp()) {
-        BinaryMintOpInstr* mintop = it.Current()->AsBinaryMintOp();
-        if (mintop->op_kind() == Token::kBIT_AND) {
-          OptimizeLeftShiftBitAndSmiOp(mintop,
-                                       mintop->left()->definition(),
-                                       mintop->right()->definition());
-        }
-      } else if (it.Current()->IsMathUnary()) {
-        MathUnaryInstr* math_unary = it.Current()->AsMathUnary();
-        if ((math_unary->kind() == MathUnaryInstr::kSin) ||
-            (math_unary->kind() == MathUnaryInstr::kCos)) {
-          if (math_unary->HasUses()) {
-            sin_cos_merge.Add(math_unary);
-          }
-        }
-      }
-    }
-    TryMergeTruncDivMod(&div_mod_merge);
-    TryMergeMathUnary(&sin_cos_merge);
-    current_iterator_ = NULL;
-  }
-}
-
-
-static void EnsureSSATempIndex(FlowGraph* graph,
-                               Definition* defn,
-                               Definition* replacement) {
-  if ((replacement->ssa_temp_index() == -1) &&
-      (defn->ssa_temp_index() != -1)) {
-    replacement->set_ssa_temp_index(graph->alloc_ssa_temp_index());
-  }
-}
-
-
-static void ReplaceCurrentInstruction(ForwardInstructionIterator* iterator,
-                                      Instruction* current,
-                                      Instruction* replacement,
-                                      FlowGraph* graph) {
-  Definition* current_defn = current->AsDefinition();
-  if ((replacement != NULL) && (current_defn != NULL)) {
-    Definition* replacement_defn = replacement->AsDefinition();
-    ASSERT(replacement_defn != NULL);
-    current_defn->ReplaceUsesWith(replacement_defn);
-    EnsureSSATempIndex(graph, current_defn, replacement_defn);
-
-    if (FLAG_trace_optimization) {
-      OS::Print("Replacing v%" Pd " with v%" Pd "\n",
-                current_defn->ssa_temp_index(),
-                replacement_defn->ssa_temp_index());
-    }
-  } else if (FLAG_trace_optimization) {
-    if (current_defn == NULL) {
-      OS::Print("Removing %s\n", current->DebugName());
-    } else {
-      ASSERT(!current_defn->HasUses());
-      OS::Print("Removing v%" Pd ".\n", current_defn->ssa_temp_index());
-    }
-  }
-  iterator->RemoveCurrentFromGraph();
-}
-
-
-bool FlowGraphOptimizer::Canonicalize() {
-  bool changed = false;
-  for (intptr_t i = 0; i < block_order_.length(); ++i) {
-    BlockEntryInstr* entry = block_order_[i];
-    for (ForwardInstructionIterator it(entry); !it.Done(); it.Advance()) {
-      Instruction* current = it.Current();
-      if (current->HasUnmatchedInputRepresentations()) {
-        // Can't canonicalize this instruction until all conversions for its
-        // inputs are inserted.
-        continue;
-      }
-
-      Instruction* replacement = current->Canonicalize(flow_graph());
-
-      if (replacement != current) {
-        // For non-definitions Canonicalize should return either NULL or
-        // this.
-        ASSERT((replacement == NULL) || current->IsDefinition());
-        ReplaceCurrentInstruction(&it, current, replacement, flow_graph_);
-        changed = true;
-      }
-    }
-  }
-  return changed;
-}
-
-
-static bool IsUnboxedInteger(Representation rep) {
-  return (rep == kUnboxedInt32) ||
-         (rep == kUnboxedUint32) ||
-         (rep == kUnboxedMint);
-}
-
-
-void FlowGraphOptimizer::InsertConversion(Representation from,
-                                          Representation to,
-                                          Value* use,
-                                          bool is_environment_use) {
-  Instruction* insert_before;
-  Instruction* deopt_target;
-  PhiInstr* phi = use->instruction()->AsPhi();
-  if (phi != NULL) {
-    ASSERT(phi->is_alive());
-    // For phis conversions have to be inserted in the predecessor.
-    insert_before =
-        phi->block()->PredecessorAt(use->use_index())->last_instruction();
-    deopt_target = NULL;
-  } else {
-    deopt_target = insert_before = use->instruction();
-  }
-
-  Definition* converted = NULL;
-  if (IsUnboxedInteger(from) && IsUnboxedInteger(to)) {
-    const intptr_t deopt_id = (to == kUnboxedInt32) && (deopt_target != NULL) ?
-      deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
-    converted = new(I) UnboxedIntConverterInstr(from,
-                                                to,
-                                                use->CopyWithType(),
-                                                deopt_id);
-  } else if ((from == kUnboxedInt32) && (to == kUnboxedDouble)) {
-    converted = new Int32ToDoubleInstr(use->CopyWithType());
-  } else if ((from == kUnboxedMint) &&
-             (to == kUnboxedDouble) &&
-             CanConvertUnboxedMintToDouble()) {
-    const intptr_t deopt_id = (deopt_target != NULL) ?
-      deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
-    ASSERT(CanUnboxDouble());
-    converted = new MintToDoubleInstr(use->CopyWithType(), deopt_id);
-  } else if ((from == kTagged) && Boxing::Supports(to)) {
-    const intptr_t deopt_id = (deopt_target != NULL) ?
-      deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
-    converted = UnboxInstr::Create(to, use->CopyWithType(), deopt_id);
-  } else if ((to == kTagged) && Boxing::Supports(from)) {
-    converted = BoxInstr::Create(from, use->CopyWithType());
-  } else {
-    // We have failed to find a suitable conversion instruction.
-    // Insert two "dummy" conversion instructions with the correct
-    // "from" and "to" representation. The inserted instructions will
-    // trigger a deoptimization if executed. See #12417 for a discussion.
-    const intptr_t deopt_id = (deopt_target != NULL) ?
-      deopt_target->DeoptimizationTarget() : Isolate::kNoDeoptId;
-    ASSERT(Boxing::Supports(from));
-    ASSERT(Boxing::Supports(to));
-    Definition* boxed = BoxInstr::Create(from, use->CopyWithType());
-    use->BindTo(boxed);
-    InsertBefore(insert_before, boxed, NULL, FlowGraph::kValue);
-    converted = UnboxInstr::Create(to, new(I) Value(boxed), deopt_id);
-  }
-  ASSERT(converted != NULL);
-  InsertBefore(insert_before, converted, use->instruction()->env(),
-               FlowGraph::kValue);
-  if (is_environment_use) {
-    use->BindToEnvironment(converted);
-  } else {
-    use->BindTo(converted);
-  }
-
-  if ((to == kUnboxedInt32) && (phi != NULL)) {
-    // Int32 phis are unboxed optimistically. Ensure that unboxing
-    // has deoptimization target attached from the goto instruction.
-    flow_graph_->CopyDeoptTarget(converted, insert_before);
-  }
-}
-
-
-void FlowGraphOptimizer::ConvertUse(Value* use, Representation from_rep) {
-  const Representation to_rep =
-      use->instruction()->RequiredInputRepresentation(use->use_index());
-  if (from_rep == to_rep || to_rep == kNoRepresentation) {
-    return;
-  }
-  InsertConversion(from_rep, to_rep, use, /*is_environment_use=*/ false);
-}
-
-
-void FlowGraphOptimizer::ConvertEnvironmentUse(Value* use,
-                                               Representation from_rep) {
-  const Representation to_rep = kTagged;
-  if (from_rep == to_rep || to_rep == kNoRepresentation) {
-    return;
-  }
-  InsertConversion(from_rep, to_rep, use, /*is_environment_use=*/ true);
-}
-
-
-void FlowGraphOptimizer::InsertConversionsFor(Definition* def) {
-  const Representation from_rep = def->representation();
-
-  for (Value::Iterator it(def->input_use_list());
-       !it.Done();
-       it.Advance()) {
-    ConvertUse(it.Current(), from_rep);
-  }
-
-  if (flow_graph()->graph_entry()->SuccessorCount() > 1) {
-    for (Value::Iterator it(def->env_use_list());
-         !it.Done();
-         it.Advance()) {
-      Value* use = it.Current();
-      if (use->instruction()->MayThrow() &&
-          use->instruction()->GetBlock()->InsideTryBlock()) {
-        // Environment uses at calls inside try-blocks must be converted to
-        // tagged representation.
-        ConvertEnvironmentUse(it.Current(), from_rep);
-      }
-    }
-  }
-}
-
-
-static void UnboxPhi(PhiInstr* phi) {
-  Representation unboxed = phi->representation();
-
-  switch (phi->Type()->ToCid()) {
-    case kDoubleCid:
-      if (CanUnboxDouble()) {
-        unboxed = kUnboxedDouble;
-      }
-      break;
-    case kFloat32x4Cid:
-      if (ShouldInlineSimd()) {
-        unboxed = kUnboxedFloat32x4;
-      }
-      break;
-    case kInt32x4Cid:
-      if (ShouldInlineSimd()) {
-        unboxed = kUnboxedInt32x4;
-      }
-      break;
-    case kFloat64x2Cid:
-      if (ShouldInlineSimd()) {
-        unboxed = kUnboxedFloat64x2;
-      }
-      break;
-  }
-
-  if ((kSmiBits < 32) &&
-      (unboxed == kTagged) &&
-      phi->Type()->IsInt() &&
-      RangeUtils::Fits(phi->range(), RangeBoundary::kRangeBoundaryInt32)) {
-    // On 32-bit platforms conservatively unbox phis that:
-    //   - are proven to be of type Int;
-    //   - fit into 32bits range;
-    //   - have either constants or Box() operations as inputs;
-    //   - have at least one Box() operation as an input;
-    //   - are used in at least 1 Unbox() operation.
-    bool should_unbox = false;
-    for (intptr_t i = 0; i < phi->InputCount(); i++) {
-      Definition* input = phi->InputAt(i)->definition();
-      if (input->IsBox() &&
-          RangeUtils::Fits(input->range(),
-                           RangeBoundary::kRangeBoundaryInt32)) {
-        should_unbox = true;
-      } else if (!input->IsConstant()) {
-        should_unbox = false;
-        break;
-      }
-    }
-
-    if (should_unbox) {
-      // We checked inputs. Check if phi is used in at least one unbox
-      // operation.
-      bool has_unboxed_use = false;
-      for (Value* use = phi->input_use_list();
-           use != NULL;
-           use = use->next_use()) {
-        Instruction* instr = use->instruction();
-        if (instr->IsUnbox()) {
-          has_unboxed_use = true;
-          break;
-        } else if (IsUnboxedInteger(
-            instr->RequiredInputRepresentation(use->use_index()))) {
-          has_unboxed_use = true;
-          break;
-        }
-      }
-
-      if (!has_unboxed_use) {
-        should_unbox = false;
-      }
-    }
-
-    if (should_unbox) {
-      unboxed = kUnboxedInt32;
-    }
-  }
-
-  phi->set_representation(unboxed);
-}
-
-
-void FlowGraphOptimizer::SelectRepresentations() {
-  // Conservatively unbox all phis that were proven to be of Double,
-  // Float32x4, or Int32x4 type.
-  for (intptr_t i = 0; i < block_order_.length(); ++i) {
-    JoinEntryInstr* join_entry = block_order_[i]->AsJoinEntry();
-    if (join_entry != NULL) {
-      for (PhiIterator it(join_entry); !it.Done(); it.Advance()) {
-        PhiInstr* phi = it.Current();
-        UnboxPhi(phi);
-      }
-    }
-  }
-
-  // Process all instructions and insert conversions where needed.
-  GraphEntryInstr* graph_entry = block_order_[0]->AsGraphEntry();
-
-  // Visit incoming parameters and constants.
-  for (intptr_t i = 0; i < graph_entry->initial_definitions()->length(); i++) {
-    InsertConversionsFor((*graph_entry->initial_definitions())[i]);
-  }
-
-  for (intptr_t i = 0; i < block_order_.length(); ++i) {
-    BlockEntryInstr* entry = block_order_[i];
-    JoinEntryInstr* join_entry = entry->AsJoinEntry();
-    if (join_entry != NULL) {
-      for (PhiIterator it(join_entry); !it.Done(); it.Advance()) {
-        PhiInstr* phi = it.Current();
-        ASSERT(phi != NULL);
-        ASSERT(phi->is_alive());
-        InsertConversionsFor(phi);
-      }
-    }
-    CatchBlockEntryInstr* catch_entry = entry->AsCatchBlockEntry();
-    if (catch_entry != NULL) {
-      for (intptr_t i = 0;
-           i < catch_entry->initial_definitions()->length();
-           i++) {
-        InsertConversionsFor((*catch_entry->initial_definitions())[i]);
-      }
-    }
-    for (ForwardInstructionIterator it(entry); !it.Done(); it.Advance()) {
-      Definition* def = it.Current()->AsDefinition();
-      if (def != NULL) {
-        InsertConversionsFor(def);
-      }
-    }
-  }
-}
-
-
-static bool ClassIdIsOneOf(intptr_t class_id,
-                           const GrowableArray<intptr_t>& class_ids) {
-  for (intptr_t i = 0; i < class_ids.length(); i++) {
-    ASSERT(class_ids[i] != kIllegalCid);
-    if (class_ids[i] == class_id) {
-      return true;
-    }
-  }
-  return false;
-}
-
-
-// Returns true if ICData tests two arguments and all ICData cids are in the
-// required sets 'receiver_class_ids' or 'argument_class_ids', respectively.
-static bool ICDataHasOnlyReceiverArgumentClassIds(
-    const ICData& ic_data,
-    const GrowableArray<intptr_t>& receiver_class_ids,
-    const GrowableArray<intptr_t>& argument_class_ids) {
-  if (ic_data.NumArgsTested() != 2) {
-    return false;
-  }
-  Function& target = Function::Handle();
-  const intptr_t len = ic_data.NumberOfChecks();
-  GrowableArray<intptr_t> class_ids;
-  for (intptr_t i = 0; i < len; i++) {
-    if (ic_data.IsUsedAt(i)) {
-      ic_data.GetCheckAt(i, &class_ids, &target);
-      ASSERT(class_ids.length() == 2);
-      if (!ClassIdIsOneOf(class_ids[0], receiver_class_ids) ||
-          !ClassIdIsOneOf(class_ids[1], argument_class_ids)) {
-        return false;
-      }
-    }
-  }
-  return true;
-}
-
-
-static bool ICDataHasReceiverArgumentClassIds(const ICData& ic_data,
-                                              intptr_t receiver_class_id,
-                                              intptr_t argument_class_id) {
-  if (ic_data.NumArgsTested() != 2) {
-    return false;
-  }
-  Function& target = Function::Handle();
-  const intptr_t len = ic_data.NumberOfChecks();
-  for (intptr_t i = 0; i < len; i++) {
-    if (ic_data.IsUsedAt(i)) {
-      GrowableArray<intptr_t> class_ids;
-      ic_data.GetCheckAt(i, &class_ids, &target);
-      ASSERT(class_ids.length() == 2);
-      if ((class_ids[0] == receiver_class_id) &&
-          (class_ids[1] == argument_class_id)) {
-        return true;
-      }
-    }
-  }
-  return false;
-}
-
-
-static bool HasOnlyOneSmi(const ICData& ic_data) {
-  return (ic_data.NumberOfUsedChecks() == 1)
-      && ic_data.HasReceiverClassId(kSmiCid);
-}
-
-
-static bool HasOnlySmiOrMint(const ICData& ic_data) {
-  if (ic_data.NumberOfUsedChecks() == 1) {
-    return ic_data.HasReceiverClassId(kSmiCid)
-        || ic_data.HasReceiverClassId(kMintCid);
-  }
-  return (ic_data.NumberOfUsedChecks() == 2)
-      && ic_data.HasReceiverClassId(kSmiCid)
-      && ic_data.HasReceiverClassId(kMintCid);
-}
-
-
-static bool HasOnlyTwoOf(const ICData& ic_data, intptr_t cid) {
-  if (ic_data.NumberOfUsedChecks() != 1) {
-    return false;
-  }
-  GrowableArray<intptr_t> first;
-  GrowableArray<intptr_t> second;
-  ic_data.GetUsedCidsForTwoArgs(&first, &second);
-  return (first[0] == cid) && (second[0] == cid);
-}
-
-// Returns false if the ICData contains anything other than the 4 combinations
-// of Mint and Smi for the receiver and argument classes.
-static bool HasTwoMintOrSmi(const ICData& ic_data) {
-  GrowableArray<intptr_t> first;
-  GrowableArray<intptr_t> second;
-  ic_data.GetUsedCidsForTwoArgs(&first, &second);
-  for (intptr_t i = 0; i < first.length(); i++) {
-    if ((first[i] != kSmiCid) && (first[i] != kMintCid)) {
-      return false;
-    }
-    if ((second[i] != kSmiCid) && (second[i] != kMintCid)) {
-      return false;
-    }
-  }
-  return true;
-}
-
-
-// Returns false if the ICData contains anything other than the 4 combinations
-// of Double and Smi for the receiver and argument classes.
-static bool HasTwoDoubleOrSmi(const ICData& ic_data) {
-  GrowableArray<intptr_t> class_ids(2);
-  class_ids.Add(kSmiCid);
-  class_ids.Add(kDoubleCid);
-  return ICDataHasOnlyReceiverArgumentClassIds(ic_data, class_ids, class_ids);
-}
-
-
-static bool HasOnlyOneDouble(const ICData& ic_data) {
-  return (ic_data.NumberOfUsedChecks() == 1)
-      && ic_data.HasReceiverClassId(kDoubleCid);
-}
-
-
-static bool ShouldSpecializeForDouble(const ICData& ic_data) {
-  // Don't specialize for double if we can't unbox them.
-  if (!CanUnboxDouble()) {
-    return false;
-  }
-
-  // Unboxed double operation can't handle case of two smis.
-  if (ICDataHasReceiverArgumentClassIds(ic_data, kSmiCid, kSmiCid)) {
-    return false;
-  }
-
-  // Check that it have seen only smis and doubles.
-  return HasTwoDoubleOrSmi(ic_data);
-}
-
-
-void FlowGraphOptimizer::ReplaceCall(Definition* call,
-                                     Definition* replacement) {
-  // Remove the original push arguments.
-  for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
-    PushArgumentInstr* push = call->PushArgumentAt(i);
-    push->ReplaceUsesWith(push->value()->definition());
-    push->RemoveFromGraph();
-  }
-  call->ReplaceWith(replacement, current_iterator());
-}
-
-
-void FlowGraphOptimizer::AddCheckSmi(Definition* to_check,
-                                     intptr_t deopt_id,
-                                     Environment* deopt_environment,
-                                     Instruction* insert_before) {
-  if (to_check->Type()->ToCid() != kSmiCid) {
-    InsertBefore(insert_before,
-                 new(I) CheckSmiInstr(new(I) Value(to_check),
-                                      deopt_id,
-                                      insert_before->token_pos()),
-                 deopt_environment,
-                 FlowGraph::kEffect);
-  }
-}
-
-
-Instruction* FlowGraphOptimizer::GetCheckClass(Definition* to_check,
-                                               const ICData& unary_checks,
-                                               intptr_t deopt_id,
-                                               intptr_t token_pos) {
-  if ((unary_checks.NumberOfUsedChecks() == 1) &&
-      unary_checks.HasReceiverClassId(kSmiCid)) {
-    return new(I) CheckSmiInstr(new(I) Value(to_check),
-                                deopt_id,
-                                token_pos);
-  }
-  return new(I) CheckClassInstr(
-      new(I) Value(to_check), deopt_id, unary_checks, token_pos);
-}
-
-
-void FlowGraphOptimizer::AddCheckClass(Definition* to_check,
-                                       const ICData& unary_checks,
-                                       intptr_t deopt_id,
-                                       Environment* deopt_environment,
-                                       Instruction* insert_before) {
-  // Type propagation has not run yet, we cannot eliminate the check.
-  Instruction* check = GetCheckClass(
-      to_check, unary_checks, deopt_id, insert_before->token_pos());
-  InsertBefore(insert_before, check, deopt_environment, FlowGraph::kEffect);
-}
-
-
-void FlowGraphOptimizer::AddReceiverCheck(InstanceCallInstr* call) {
-  AddCheckClass(call->ArgumentAt(0),
-                ICData::ZoneHandle(I, call->ic_data()->AsUnaryClassChecks()),
-                call->deopt_id(),
-                call->env(),
-                call);
-}
-
-
-static bool ArgIsAlways(intptr_t cid,
-                        const ICData& ic_data,
-                        intptr_t arg_number) {
-  ASSERT(ic_data.NumArgsTested() > arg_number);
-  if (ic_data.NumberOfUsedChecks() == 0) {
-    return false;
-  }
-  const intptr_t num_checks = ic_data.NumberOfChecks();
-  for (intptr_t i = 0; i < num_checks; i++) {
-    if (ic_data.IsUsedAt(i) && ic_data.GetClassIdAt(i, arg_number) != cid) {
-      return false;
-    }
-  }
-  return true;
-}
-
-
-static bool CanUnboxInt32() {
-  // Int32/Uint32 can be unboxed if it fits into a smi or the platform
-  // supports unboxed mints.
-  return (kSmiBits >= 32) || FlowGraphCompiler::SupportsUnboxedMints();
-}
-
-
-static intptr_t MethodKindToCid(MethodRecognizer::Kind kind) {
-  switch (kind) {
-    case MethodRecognizer::kImmutableArrayGetIndexed:
-      return kImmutableArrayCid;
-
-    case MethodRecognizer::kObjectArrayGetIndexed:
-    case MethodRecognizer::kObjectArraySetIndexed:
-      return kArrayCid;
-
-    case MethodRecognizer::kGrowableArrayGetIndexed:
-    case MethodRecognizer::kGrowableArraySetIndexed:
-      return kGrowableObjectArrayCid;
-
-    case MethodRecognizer::kFloat32ArrayGetIndexed:
-    case MethodRecognizer::kFloat32ArraySetIndexed:
-      return kTypedDataFloat32ArrayCid;
-
-    case MethodRecognizer::kFloat64ArrayGetIndexed:
-    case MethodRecognizer::kFloat64ArraySetIndexed:
-      return kTypedDataFloat64ArrayCid;
-
-    case MethodRecognizer::kInt8ArrayGetIndexed:
-    case MethodRecognizer::kInt8ArraySetIndexed:
-      return kTypedDataInt8ArrayCid;
-
-    case MethodRecognizer::kUint8ArrayGetIndexed:
-    case MethodRecognizer::kUint8ArraySetIndexed:
-      return kTypedDataUint8ArrayCid;
-
-    case MethodRecognizer::kUint8ClampedArrayGetIndexed:
-    case MethodRecognizer::kUint8ClampedArraySetIndexed:
-      return kTypedDataUint8ClampedArrayCid;
-
-    case MethodRecognizer::kExternalUint8ArrayGetIndexed:
-    case MethodRecognizer::kExternalUint8ArraySetIndexed:
-      return kExternalTypedDataUint8ArrayCid;
-
-    case MethodRecognizer::kExternalUint8ClampedArrayGetIndexed:
-    case MethodRecognizer::kExternalUint8ClampedArraySetIndexed:
-      return kExternalTypedDataUint8ClampedArrayCid;
-
-    case MethodRecognizer::kInt16ArrayGetIndexed:
-    case MethodRecognizer::kInt16ArraySetIndexed:
-      return kTypedDataInt16ArrayCid;
-
-    case MethodRecognizer::kUint16ArrayGetIndexed:
-    case MethodRecognizer::kUint16ArraySetIndexed:
-      return kTypedDataUint16ArrayCid;
-
-    case MethodRecognizer::kInt32ArrayGetIndexed:
-    case MethodRecognizer::kInt32ArraySetIndexed:
-      return kTypedDataInt32ArrayCid;
-
-    case MethodRecognizer::kUint32ArrayGetIndexed:
-    case MethodRecognizer::kUint32ArraySetIndexed:
-      return kTypedDataUint32ArrayCid;
-
-    case MethodRecognizer::kInt64ArrayGetIndexed:
-    case MethodRecognizer::kInt64ArraySetIndexed:
-      return kTypedDataInt64ArrayCid;
-
-    case MethodRecognizer::kFloat32x4ArrayGetIndexed:
-    case MethodRecognizer::kFloat32x4ArraySetIndexed:
-      return kTypedDataFloat32x4ArrayCid;
-
-    case MethodRecognizer::kInt32x4ArrayGetIndexed:
-    case MethodRecognizer::kInt32x4ArraySetIndexed:
-      return kTypedDataInt32x4ArrayCid;
-
-    case MethodRecognizer::kFloat64x2ArrayGetIndexed:
-    case MethodRecognizer::kFloat64x2ArraySetIndexed:
-      return kTypedDataFloat64x2ArrayCid;
-
-    default:
-      break;
-  }
-  return kIllegalCid;
-}
-
-
-bool FlowGraphOptimizer::TryReplaceWithStoreIndexed(InstanceCallInstr* call) {
-  // Check for monomorphic IC data.
-  if (!call->HasICData()) return false;
-  const ICData& ic_data =
-      ICData::Handle(I, call->ic_data()->AsUnaryClassChecks());
-  if (ic_data.NumberOfChecks() != 1) {
-    return false;
-  }
-  ASSERT(ic_data.NumberOfUsedChecks() == 1);
-  ASSERT(ic_data.HasOneTarget());
-
-  const Function& target = Function::Handle(I, ic_data.GetTargetAt(0));
-  TargetEntryInstr* entry;
-  Definition* last;
-  if (!TryInlineRecognizedMethod(ic_data.GetReceiverClassIdAt(0),
-                                 target,
-                                 call,
-                                 call->ArgumentAt(0),
-                                 call->token_pos(),
-                                 *call->ic_data(),
-                                 &entry, &last)) {
-    return false;
-  }
-  // Insert receiver class check.
-  AddReceiverCheck(call);
-  // Remove the original push arguments.
-  for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
-    PushArgumentInstr* push = call->PushArgumentAt(i);
-    push->ReplaceUsesWith(push->value()->definition());
-    push->RemoveFromGraph();
-  }
-  // Replace all uses of this definition with the result.
-  call->ReplaceUsesWith(last);
-  // Finally insert the sequence other definition in place of this one in the
-  // graph.
-  call->previous()->LinkTo(entry->next());
-  entry->UnuseAllInputs();  // Entry block is not in the graph.
-  last->LinkTo(call);
-  // Remove through the iterator.
-  ASSERT(current_iterator()->Current() == call);
-  current_iterator()->RemoveCurrentFromGraph();
-  call->set_previous(NULL);
-  call->set_next(NULL);
-  return true;
-}
-
-
-bool FlowGraphOptimizer::InlineSetIndexed(
-    MethodRecognizer::Kind kind,
-    const Function& target,
-    Instruction* call,
-    Definition* receiver,
-    intptr_t token_pos,
-    const ICData* ic_data,
-    const ICData& value_check,
-    TargetEntryInstr** entry,
-    Definition** last) {
-  intptr_t array_cid = MethodKindToCid(kind);
-  ASSERT(array_cid != kIllegalCid);
-
-  Definition* array = receiver;
-  Definition* index = call->ArgumentAt(1);
-  Definition* stored_value = call->ArgumentAt(2);
-
-  *entry = new(I) TargetEntryInstr(flow_graph()->allocate_block_id(),
-                                   call->GetBlock()->try_index());
-  (*entry)->InheritDeoptTarget(I, call);
-  Instruction* cursor = *entry;
-  if (FLAG_enable_type_checks) {
-    // Only type check for the value. A type check for the index is not
-    // needed here because we insert a deoptimizing smi-check for the case
-    // the index is not a smi.
-    const AbstractType& value_type =
-        AbstractType::ZoneHandle(I, target.ParameterTypeAt(2));
-    Definition* instantiator = NULL;
-    Definition* type_args = NULL;
-    switch (array_cid) {
-      case kArrayCid:
-      case kGrowableObjectArrayCid: {
-        const Class& instantiator_class =  Class::Handle(I, target.Owner());
-        intptr_t type_arguments_field_offset =
-            instantiator_class.type_arguments_field_offset();
-        LoadFieldInstr* load_type_args =
-            new(I) LoadFieldInstr(new(I) Value(array),
-                                  type_arguments_field_offset,
-                                  Type::ZoneHandle(I),  // No type.
-                                  call->token_pos());
-        cursor = flow_graph()->AppendTo(cursor,
-                                        load_type_args,
-                                        NULL,
-                                        FlowGraph::kValue);
-
-        instantiator = array;
-        type_args = load_type_args;
-        break;
-      }
-      case kTypedDataInt8ArrayCid:
-      case kTypedDataUint8ArrayCid:
-      case kTypedDataUint8ClampedArrayCid:
-      case kExternalTypedDataUint8ArrayCid:
-      case kExternalTypedDataUint8ClampedArrayCid:
-      case kTypedDataInt16ArrayCid:
-      case kTypedDataUint16ArrayCid:
-      case kTypedDataInt32ArrayCid:
-      case kTypedDataUint32ArrayCid:
-      case kTypedDataInt64ArrayCid:
-        ASSERT(value_type.IsIntType());
-        // Fall through.
-      case kTypedDataFloat32ArrayCid:
-      case kTypedDataFloat64ArrayCid: {
-        type_args = instantiator = flow_graph_->constant_null();
-        ASSERT((array_cid != kTypedDataFloat32ArrayCid &&
-                array_cid != kTypedDataFloat64ArrayCid) ||
-               value_type.IsDoubleType());
-        ASSERT(value_type.IsInstantiated());
-        break;
-      }
-      case kTypedDataFloat32x4ArrayCid: {
-        type_args = instantiator = flow_graph_->constant_null();
-        ASSERT((array_cid != kTypedDataFloat32x4ArrayCid) ||
-               value_type.IsFloat32x4Type());
-        ASSERT(value_type.IsInstantiated());
-        break;
-      }
-      case kTypedDataFloat64x2ArrayCid: {
-        type_args = instantiator = flow_graph_->constant_null();
-        ASSERT((array_cid != kTypedDataFloat64x2ArrayCid) ||
-               value_type.IsFloat64x2Type());
-        ASSERT(value_type.IsInstantiated());
-        break;
-      }
-      default:
-        // TODO(fschneider): Add support for other array types.
-        UNREACHABLE();
-    }
-    AssertAssignableInstr* assert_value =
-        new(I) AssertAssignableInstr(token_pos,
-                                     new(I) Value(stored_value),
-                                     new(I) Value(instantiator),
-                                     new(I) Value(type_args),
-                                     value_type,
-                                     Symbols::Value(),
-                                     call->deopt_id());
-    cursor = flow_graph()->AppendTo(cursor,
-                                    assert_value,
-                                    call->env(),
-                                    FlowGraph::kValue);
-  }
-
-  array_cid = PrepareInlineIndexedOp(call,
-                                     array_cid,
-                                     &array,
-                                     index,
-                                     &cursor);
-
-  // Check if store barrier is needed. Byte arrays don't need a store barrier.
-  StoreBarrierType needs_store_barrier =
-      (RawObject::IsTypedDataClassId(array_cid) ||
-       RawObject::IsTypedDataViewClassId(array_cid) ||
-       RawObject::IsExternalTypedDataClassId(array_cid)) ? kNoStoreBarrier
-                                                         : kEmitStoreBarrier;
-
-  // No need to class check stores to Int32 and Uint32 arrays because
-  // we insert unboxing instructions below which include a class check.
-  if ((array_cid != kTypedDataUint32ArrayCid) &&
-      (array_cid != kTypedDataInt32ArrayCid) &&
-      !value_check.IsNull()) {
-    // No store barrier needed because checked value is a smi, an unboxed mint,
-    // an unboxed double, an unboxed Float32x4, or unboxed Int32x4.
-    needs_store_barrier = kNoStoreBarrier;
-    Instruction* check = GetCheckClass(
-        stored_value, value_check, call->deopt_id(), call->token_pos());
-    cursor = flow_graph()->AppendTo(cursor,
-                                    check,
-                                    call->env(),
-                                    FlowGraph::kEffect);
-  }
-
-  if (array_cid == kTypedDataFloat32ArrayCid) {
-    stored_value =
-        new(I) DoubleToFloatInstr(
-            new(I) Value(stored_value), call->deopt_id());
-    cursor = flow_graph()->AppendTo(cursor,
-                                    stored_value,
-                                    NULL,
-                                    FlowGraph::kValue);
-  } else if (array_cid == kTypedDataInt32ArrayCid) {
-    stored_value = new(I) UnboxInt32Instr(
-        UnboxInt32Instr::kTruncate,
-        new(I) Value(stored_value),
-        call->deopt_id());
-    cursor = flow_graph()->AppendTo(cursor,
-                                    stored_value,
-                                    call->env(),
-                                    FlowGraph::kValue);
-  } else if (array_cid == kTypedDataUint32ArrayCid) {
-    stored_value = new(I) UnboxUint32Instr(
-        new(I) Value(stored_value),
-        call->deopt_id());
-    ASSERT(stored_value->AsUnboxInteger()->is_truncating());
-    cursor = flow_graph()->AppendTo(cursor,
-                                    stored_value,
-                                    call->env(),
-                                    FlowGraph::kValue);
-  }
-
-  const intptr_t index_scale = Instance::ElementSizeFor(array_cid);
-  *last = new(I) StoreIndexedInstr(new(I) Value(array),
-                                   new(I) Value(index),
-                                   new(I) Value(stored_value),
-                                   needs_store_barrier,
-                                   index_scale,
-                                   array_cid,
-                                   call->deopt_id(),
-                                   call->token_pos());
-  flow_graph()->AppendTo(cursor,
-                         *last,
-                         call->env(),
-                         FlowGraph::kEffect);
-  return true;
-}
-
-
-bool FlowGraphOptimizer::TryInlineRecognizedMethod(intptr_t receiver_cid,
-                                                   const Function& target,
-                                                   Instruction* call,
-                                                   Definition* receiver,
-                                                   intptr_t token_pos,
-                                                   const ICData& ic_data,
-                                                   TargetEntryInstr** entry,
-                                                   Definition** last) {
-  ICData& value_check = ICData::ZoneHandle(I);
-  MethodRecognizer::Kind kind = MethodRecognizer::RecognizeKind(target);
-  switch (kind) {
-    // Recognized [] operators.
-    case MethodRecognizer::kImmutableArrayGetIndexed:
-    case MethodRecognizer::kObjectArrayGetIndexed:
-    case MethodRecognizer::kGrowableArrayGetIndexed:
-    case MethodRecognizer::kInt8ArrayGetIndexed:
-    case MethodRecognizer::kUint8ArrayGetIndexed:
-    case MethodRecognizer::kUint8ClampedArrayGetIndexed:
-    case MethodRecognizer::kExternalUint8ArrayGetIndexed:
-    case MethodRecognizer::kExternalUint8ClampedArrayGetIndexed:
-    case MethodRecognizer::kInt16ArrayGetIndexed:
-    case MethodRecognizer::kUint16ArrayGetIndexed:
-      return InlineGetIndexed(kind, call, receiver, ic_data, entry, last);
-    case MethodRecognizer::kFloat32ArrayGetIndexed:
-    case MethodRecognizer::kFloat64ArrayGetIndexed:
-      if (!CanUnboxDouble()) {
-        return false;
-      }
-      return InlineGetIndexed(kind, call, receiver, ic_data, entry, last);
-    case MethodRecognizer::kFloat32x4ArrayGetIndexed:
-    case MethodRecognizer::kFloat64x2ArrayGetIndexed:
-      if (!ShouldInlineSimd()) {
-        return false;
-      }
-      return InlineGetIndexed(kind, call, receiver, ic_data, entry, last);
-    case MethodRecognizer::kInt32ArrayGetIndexed:
-    case MethodRecognizer::kUint32ArrayGetIndexed:
-      if (!CanUnboxInt32()) return false;
-      return InlineGetIndexed(kind, call, receiver, ic_data, entry, last);
-
-    case MethodRecognizer::kInt64ArrayGetIndexed:
-      if (!ShouldInlineInt64ArrayOps()) {
-        return false;
-      }
-      return InlineGetIndexed(kind, call, receiver, ic_data, entry, last);
-    // Recognized []= operators.
-    case MethodRecognizer::kObjectArraySetIndexed:
-    case MethodRecognizer::kGrowableArraySetIndexed:
-      if (ArgIsAlways(kSmiCid, ic_data, 2)) {
-        value_check = ic_data.AsUnaryClassChecksForArgNr(2);
-      }
-      return InlineSetIndexed(kind, target, call, receiver, token_pos,
-                              &ic_data, value_check, entry, last);
-    case MethodRecognizer::kInt8ArraySetIndexed:
-    case MethodRecognizer::kUint8ArraySetIndexed:
-    case MethodRecognizer::kUint8ClampedArraySetIndexed:
-    case MethodRecognizer::kExternalUint8ArraySetIndexed:
-    case MethodRecognizer::kExternalUint8ClampedArraySetIndexed:
-    case MethodRecognizer::kInt16ArraySetIndexed:
-    case MethodRecognizer::kUint16ArraySetIndexed:
-      if (!ArgIsAlways(kSmiCid, ic_data, 2)) {
-        return false;
-      }
-      value_check = ic_data.AsUnaryClassChecksForArgNr(2);
-      return InlineSetIndexed(kind, target, call, receiver, token_pos,
-                              &ic_data, value_check, entry, last);
-    case MethodRecognizer::kInt32ArraySetIndexed:
-    case MethodRecognizer::kUint32ArraySetIndexed:
-      // Check that value is always smi or mint. We use Int32/Uint32 unboxing
-      // which can only deal unbox these values.
-      value_check = ic_data.AsUnaryClassChecksForArgNr(2);
-      if (!HasOnlySmiOrMint(value_check)) {
-        return false;
-      }
-      return InlineSetIndexed(kind, target, call, receiver, token_pos,
-                              &ic_data, value_check, entry, last);
-    case MethodRecognizer::kInt64ArraySetIndexed:
-      if (!ShouldInlineInt64ArrayOps()) {
-        return false;
-      }
-      return InlineSetIndexed(kind, target, call, receiver, token_pos,
-                              &ic_data, value_check, entry, last);
-    case MethodRecognizer::kFloat32ArraySetIndexed:
-    case MethodRecognizer::kFloat64ArraySetIndexed:
-      if (!CanUnboxDouble()) {
-        return false;
-      }
-      // Check that value is always double.
-      if (!ArgIsAlways(kDoubleCid, ic_data, 2)) {
-        return false;
-      }
-      value_check = ic_data.AsUnaryClassChecksForArgNr(2);
-      return InlineSetIndexed(kind, target, call, receiver, token_pos,
-                              &ic_data, value_check, entry, last);
-    case MethodRecognizer::kFloat32x4ArraySetIndexed:
-      if (!ShouldInlineSimd()) {
-        return false;
-      }
-      // Check that value is always a Float32x4.
-      if (!ArgIsAlways(kFloat32x4Cid, ic_data, 2)) {
-        return false;
-      }
-      value_check = ic_data.AsUnaryClassChecksForArgNr(2);
-      return InlineSetIndexed(kind, target, call, receiver, token_pos,
-                              &ic_data, value_check, entry, last);
-    case MethodRecognizer::kFloat64x2ArraySetIndexed:
-      if (!ShouldInlineSimd()) {
-        return false;
-      }
-      // Check that value is always a Float32x4.
-      if (!ArgIsAlways(kFloat64x2Cid, ic_data, 2)) {
-        return false;
-      }
-      value_check = ic_data.AsUnaryClassChecksForArgNr(2);
-      return InlineSetIndexed(kind, target, call, receiver, token_pos,
-                              &ic_data, value_check, entry, last);
-    case MethodRecognizer::kByteArrayBaseGetInt8:
-      return InlineByteArrayViewLoad(call, receiver, receiver_cid,
-                                     kTypedDataInt8ArrayCid,
-                                     ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseGetUint8:
-      return InlineByteArrayViewLoad(call, receiver, receiver_cid,
-                                     kTypedDataUint8ArrayCid,
-                                     ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseGetInt16:
-      return InlineByteArrayViewLoad(call, receiver, receiver_cid,
-                                     kTypedDataInt16ArrayCid,
-                                     ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseGetUint16:
-      return InlineByteArrayViewLoad(call, receiver, receiver_cid,
-                                     kTypedDataUint16ArrayCid,
-                                     ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseGetInt32:
-      if (!CanUnboxInt32()) {
-        return false;
-      }
-      return InlineByteArrayViewLoad(call, receiver, receiver_cid,
-                                     kTypedDataInt32ArrayCid,
-                                     ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseGetUint32:
-      if (!CanUnboxInt32()) {
-        return false;
-      }
-      return InlineByteArrayViewLoad(call, receiver, receiver_cid,
-                                     kTypedDataUint32ArrayCid,
-                                     ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseGetFloat32:
-      if (!CanUnboxDouble()) {
-        return false;
-      }
-      return InlineByteArrayViewLoad(call, receiver, receiver_cid,
-                                     kTypedDataFloat32ArrayCid,
-                                     ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseGetFloat64:
-      if (!CanUnboxDouble()) {
-        return false;
-      }
-      return InlineByteArrayViewLoad(call, receiver, receiver_cid,
-                                     kTypedDataFloat64ArrayCid,
-                                     ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseGetFloat32x4:
-      if (!ShouldInlineSimd()) {
-        return false;
-      }
-      return InlineByteArrayViewLoad(call, receiver, receiver_cid,
-                                     kTypedDataFloat32x4ArrayCid,
-                                     ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseGetInt32x4:
-      if (!ShouldInlineSimd()) {
-        return false;
-      }
-      return InlineByteArrayViewLoad(call, receiver, receiver_cid,
-                                     kTypedDataInt32x4ArrayCid,
-                                     ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseSetInt8:
-      return InlineByteArrayViewStore(target, call, receiver, receiver_cid,
-                                      kTypedDataInt8ArrayCid,
-                                      ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseSetUint8:
-      return InlineByteArrayViewStore(target, call, receiver, receiver_cid,
-                                      kTypedDataUint8ArrayCid,
-                                      ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseSetInt16:
-      return InlineByteArrayViewStore(target, call, receiver, receiver_cid,
-                                      kTypedDataInt16ArrayCid,
-                                      ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseSetUint16:
-      return InlineByteArrayViewStore(target, call, receiver, receiver_cid,
-                                      kTypedDataUint16ArrayCid,
-                                      ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseSetInt32:
-      return InlineByteArrayViewStore(target, call, receiver, receiver_cid,
-                                      kTypedDataInt32ArrayCid,
-                                      ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseSetUint32:
-      return InlineByteArrayViewStore(target, call, receiver, receiver_cid,
-                                      kTypedDataUint32ArrayCid,
-                                      ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseSetFloat32:
-      if (!CanUnboxDouble()) {
-        return false;
-      }
-      return InlineByteArrayViewStore(target, call, receiver, receiver_cid,
-                                      kTypedDataFloat32ArrayCid,
-                                      ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseSetFloat64:
-      if (!CanUnboxDouble()) {
-        return false;
-      }
-      return InlineByteArrayViewStore(target, call, receiver, receiver_cid,
-                                      kTypedDataFloat64ArrayCid,
-                                      ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseSetFloat32x4:
-      if (!ShouldInlineSimd()) {
-        return false;
-      }
-      return InlineByteArrayViewStore(target, call, receiver, receiver_cid,
-                                      kTypedDataFloat32x4ArrayCid,
-                                      ic_data, entry, last);
-    case MethodRecognizer::kByteArrayBaseSetInt32x4:
-      if (!ShouldInlineSimd()) {
-        return false;
-      }
-      return InlineByteArrayViewStore(target, call, receiver, receiver_cid,
-                                      kTypedDataInt32x4ArrayCid,
-                                      ic_data, entry, last);
-    case MethodRecognizer::kStringBaseCodeUnitAt:
-      return InlineStringCodeUnitAt(call, receiver_cid, entry, last);
-    case MethodRecognizer::kStringBaseCharAt:
-      return InlineStringBaseCharAt(call, receiver_cid, entry, last);
-    case MethodRecognizer::kDoubleAdd:
-      return InlineDoubleOp(Token::kADD, call, entry, last);
-    case MethodRecognizer::kDoubleSub:
-      return InlineDoubleOp(Token::kSUB, call, entry, last);
-    case MethodRecognizer::kDoubleMul:
-      return InlineDoubleOp(Token::kMUL, call, entry, last);
-    case MethodRecognizer::kDoubleDiv:
-      return InlineDoubleOp(Token::kDIV, call, entry, last);
-    default:
-      return false;
-  }
-}
-
-
-intptr_t FlowGraphOptimizer::PrepareInlineIndexedOp(Instruction* call,
-                                                    intptr_t array_cid,
-                                                    Definition** array,
-                                                    Definition* index,
-                                                    Instruction** cursor) {
-  // Insert index smi check.
-  *cursor = flow_graph()->AppendTo(
-      *cursor,
-      new(I) CheckSmiInstr(new(I) Value(index),
-                           call->deopt_id(),
-                           call->token_pos()),
-      call->env(),
-      FlowGraph::kEffect);
-
-  // Insert array length load and bounds check.
-  LoadFieldInstr* length =
-      new(I) LoadFieldInstr(
-          new(I) Value(*array),
-          CheckArrayBoundInstr::LengthOffsetFor(array_cid),
-          Type::ZoneHandle(I, Type::SmiType()),
-          call->token_pos());
-  length->set_is_immutable(
-      CheckArrayBoundInstr::IsFixedLengthArrayType(array_cid));
-  length->set_result_cid(kSmiCid);
-  length->set_recognized_kind(
-      LoadFieldInstr::RecognizedKindFromArrayCid(array_cid));
-  *cursor = flow_graph()->AppendTo(*cursor,
-                                   length,
-                                   NULL,
-                                   FlowGraph::kValue);
-
-  *cursor = flow_graph()->AppendTo(*cursor,
-                                   new(I) CheckArrayBoundInstr(
-                                       new(I) Value(length),
-                                       new(I) Value(index),
-                                       call->deopt_id()),
-                                   call->env(),
-                                   FlowGraph::kEffect);
-
-  if (array_cid == kGrowableObjectArrayCid) {
-    // Insert data elements load.
-    LoadFieldInstr* elements =
-        new(I) LoadFieldInstr(
-            new(I) Value(*array),
-            GrowableObjectArray::data_offset(),
-            Type::ZoneHandle(I, Type::DynamicType()),
-            call->token_pos());
-    elements->set_result_cid(kArrayCid);
-    *cursor = flow_graph()->AppendTo(*cursor,
-                                     elements,
-                                     NULL,
-                                     FlowGraph::kValue);
-    // Load from the data from backing store which is a fixed-length array.
-    *array = elements;
-    array_cid = kArrayCid;
-  } else if (RawObject::IsExternalTypedDataClassId(array_cid)) {
-    LoadUntaggedInstr* elements =
-        new(I) LoadUntaggedInstr(new(I) Value(*array),
-                                 ExternalTypedData::data_offset());
-    *cursor = flow_graph()->AppendTo(*cursor,
-                                     elements,
-                                     NULL,
-                                     FlowGraph::kValue);
-    *array = elements;
-  }
-  return array_cid;
-}
-
-
-bool FlowGraphOptimizer::InlineGetIndexed(MethodRecognizer::Kind kind,
-                                          Instruction* call,
-                                          Definition* receiver,
-                                          const ICData& ic_data,
-                                          TargetEntryInstr** entry,
-                                          Definition** last) {
-  intptr_t array_cid = MethodKindToCid(kind);
-  ASSERT(array_cid != kIllegalCid);
-
-  Definition* array = receiver;
-  Definition* index = call->ArgumentAt(1);
-  *entry = new(I) TargetEntryInstr(flow_graph()->allocate_block_id(),
-                                   call->GetBlock()->try_index());
-  (*entry)->InheritDeoptTarget(I, call);
-  Instruction* cursor = *entry;
-
-  array_cid = PrepareInlineIndexedOp(call,
-                                     array_cid,
-                                     &array,
-                                     index,
-                                     &cursor);
-
-  intptr_t deopt_id = Isolate::kNoDeoptId;
-  if ((array_cid == kTypedDataInt32ArrayCid) ||
-      (array_cid == kTypedDataUint32ArrayCid)) {
-    // Deoptimization may be needed if result does not always fit in a Smi.
-    deopt_id = (kSmiBits >= 32) ? Isolate::kNoDeoptId : call->deopt_id();
-  }
-
-  // Array load and return.
-  intptr_t index_scale = Instance::ElementSizeFor(array_cid);
-  *last = new(I) LoadIndexedInstr(new(I) Value(array),
-                                  new(I) Value(index),
-                                  index_scale,
-                                  array_cid,
-                                  deopt_id,
-                                  call->token_pos());
-  cursor = flow_graph()->AppendTo(
-      cursor,
-      *last,
-      deopt_id != Isolate::kNoDeoptId ? call->env() : NULL,
-      FlowGraph::kValue);
-
-  if (array_cid == kTypedDataFloat32ArrayCid) {
-    *last = new(I) FloatToDoubleInstr(new(I) Value(*last), deopt_id);
-    flow_graph()->AppendTo(cursor,
-                           *last,
-                           deopt_id != Isolate::kNoDeoptId ? call->env() : NULL,
-                           FlowGraph::kValue);
-  }
-  return true;
-}
-
-
-bool FlowGraphOptimizer::TryReplaceWithLoadIndexed(InstanceCallInstr* call) {
-  // Check for monomorphic IC data.
-  if (!call->HasICData()) return false;
-  const ICData& ic_data =
-      ICData::Handle(I, call->ic_data()->AsUnaryClassChecks());
-  if (ic_data.NumberOfChecks() != 1) {
-    return false;
-  }
-  ASSERT(ic_data.NumberOfUsedChecks() == 1);
-  ASSERT(ic_data.HasOneTarget());
-
-  const Function& target = Function::Handle(I, ic_data.GetTargetAt(0));
-  TargetEntryInstr* entry;
-  Definition* last;
-  if (!TryInlineRecognizedMethod(ic_data.GetReceiverClassIdAt(0),
-                                 target,
-                                 call,
-                                 call->ArgumentAt(0),
-                                 call->token_pos(),
-                                 *call->ic_data(),
-                                 &entry, &last)) {
-    return false;
-  }
-
-  // Insert receiver class check.
-  AddReceiverCheck(call);
-  // Remove the original push arguments.
-  for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
-    PushArgumentInstr* push = call->PushArgumentAt(i);
-    push->ReplaceUsesWith(push->value()->definition());
-    push->RemoveFromGraph();
-  }
-  // Replace all uses of this definition with the result.
-  call->ReplaceUsesWith(last);
-  // Finally insert the sequence other definition in place of this one in the
-  // graph.
-  call->previous()->LinkTo(entry->next());
-  entry->UnuseAllInputs();  // Entry block is not in the graph.
-  last->LinkTo(call);
-  // Remove through the iterator.
-  ASSERT(current_iterator()->Current() == call);
-  current_iterator()->RemoveCurrentFromGraph();
-  call->set_previous(NULL);
-  call->set_next(NULL);
-  return true;
-}
-
-
-// Return true if d is a string of length one (a constant or result from
-// from string-from-char-code instruction.
-static bool IsLengthOneString(Definition* d) {
-  if (d->IsConstant()) {
-    const Object& obj = d->AsConstant()->value();
-    if (obj.IsString()) {
-      return String::Cast(obj).Length() == 1;
-    } else {
-      return false;
-    }
-  } else {
-    return d->IsStringFromCharCode();
-  }
-}
-
-
-// Returns true if the string comparison was converted into char-code
-// comparison. Conversion is only possible for strings of length one.
-// E.g., detect str[x] == "x"; and use an integer comparison of char-codes.
-// TODO(srdjan): Expand for two-byte and external strings.
-bool FlowGraphOptimizer::TryStringLengthOneEquality(InstanceCallInstr* call,
-                                                    Token::Kind op_kind) {
-  ASSERT(HasOnlyTwoOf(*call->ic_data(), kOneByteStringCid));
-  // Check that left and right are length one strings (either string constants
-  // or results of string-from-char-code.
-  Definition* left = call->ArgumentAt(0);
-  Definition* right = call->ArgumentAt(1);
-  Value* left_val = NULL;
-  Definition* to_remove_left = NULL;
-  if (IsLengthOneString(right)) {
-    // Swap, since we know that both arguments are strings
-    Definition* temp = left;
-    left = right;
-    right = temp;
-  }
-  if (IsLengthOneString(left)) {
-    // Optimize if left is a string with length one (either constant or
-    // result of string-from-char-code.
-    if (left->IsConstant()) {
-      ConstantInstr* left_const = left->AsConstant();
-      const String& str = String::Cast(left_const->value());
-      ASSERT(str.Length() == 1);
-      ConstantInstr* char_code_left = flow_graph()->GetConstant(
-          Smi::ZoneHandle(I, Smi::New(static_cast<intptr_t>(str.CharAt(0)))));
-      left_val = new(I) Value(char_code_left);
-    } else if (left->IsStringFromCharCode()) {
-      // Use input of string-from-charcode as left value.
-      StringFromCharCodeInstr* instr = left->AsStringFromCharCode();
-      left_val = new(I) Value(instr->char_code()->definition());
-      to_remove_left = instr;
-    } else {
-      // IsLengthOneString(left) should have been false.
-      UNREACHABLE();
-    }
-
-    Definition* to_remove_right = NULL;
-    Value* right_val = NULL;
-    if (right->IsStringFromCharCode()) {
-      // Skip string-from-char-code, and use its input as right value.
-      StringFromCharCodeInstr* right_instr = right->AsStringFromCharCode();
-      right_val = new(I) Value(right_instr->char_code()->definition());
-      to_remove_right = right_instr;
-    } else {
-      const ICData& unary_checks_1 =
-          ICData::ZoneHandle(I, call->ic_data()->AsUnaryClassChecksForArgNr(1));
-      AddCheckClass(right,
-                    unary_checks_1,
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      // String-to-char-code instructions returns -1 (illegal charcode) if
-      // string is not of length one.
-      StringToCharCodeInstr* char_code_right =
-          new(I) StringToCharCodeInstr(new(I) Value(right), kOneByteStringCid);
-      InsertBefore(call, char_code_right, call->env(), FlowGraph::kValue);
-      right_val = new(I) Value(char_code_right);
-    }
-
-    // Comparing char-codes instead of strings.
-    EqualityCompareInstr* comp =
-        new(I) EqualityCompareInstr(call->token_pos(),
-                                    op_kind,
-                                    left_val,
-                                    right_val,
-                                    kSmiCid,
-                                    call->deopt_id());
-    ReplaceCall(call, comp);
-
-    // Remove dead instructions.
-    if ((to_remove_left != NULL) &&
-        (to_remove_left->input_use_list() == NULL)) {
-      to_remove_left->ReplaceUsesWith(flow_graph()->constant_null());
-      to_remove_left->RemoveFromGraph();
-    }
-    if ((to_remove_right != NULL) &&
-        (to_remove_right->input_use_list() == NULL)) {
-      to_remove_right->ReplaceUsesWith(flow_graph()->constant_null());
-      to_remove_right->RemoveFromGraph();
-    }
-    return true;
-  }
-  return false;
-}
-
-
-static bool SmiFitsInDouble() { return kSmiBits < 53; }
-
-bool FlowGraphOptimizer::TryReplaceWithEqualityOp(InstanceCallInstr* call,
-                                                  Token::Kind op_kind) {
-  const ICData& ic_data = *call->ic_data();
-  ASSERT(ic_data.NumArgsTested() == 2);
-
-  ASSERT(call->ArgumentCount() == 2);
-  Definition* left = call->ArgumentAt(0);
-  Definition* right = call->ArgumentAt(1);
-
-  intptr_t cid = kIllegalCid;
-  if (HasOnlyTwoOf(ic_data, kOneByteStringCid)) {
-    if (TryStringLengthOneEquality(call, op_kind)) {
-      return true;
-    } else {
-      return false;
-    }
-  } else if (HasOnlyTwoOf(ic_data, kSmiCid)) {
-    InsertBefore(call,
-                 new(I) CheckSmiInstr(new(I) Value(left),
-                                      call->deopt_id(),
-                                      call->token_pos()),
-                 call->env(),
-                 FlowGraph::kEffect);
-    InsertBefore(call,
-                 new(I) CheckSmiInstr(new(I) Value(right),
-                                      call->deopt_id(),
-                                      call->token_pos()),
-                 call->env(),
-                 FlowGraph::kEffect);
-    cid = kSmiCid;
-  } else if (HasTwoMintOrSmi(ic_data) &&
-             FlowGraphCompiler::SupportsUnboxedMints()) {
-    cid = kMintCid;
-  } else if (HasTwoDoubleOrSmi(ic_data) && CanUnboxDouble()) {
-    // Use double comparison.
-    if (SmiFitsInDouble()) {
-      cid = kDoubleCid;
-    } else {
-      if (ICDataHasReceiverArgumentClassIds(ic_data, kSmiCid, kSmiCid)) {
-        // We cannot use double comparison on two smis. Need polymorphic
-        // call.
-        return false;
-      } else {
-        InsertBefore(call,
-                     new(I) CheckEitherNonSmiInstr(
-                         new(I) Value(left),
-                         new(I) Value(right),
-                         call->deopt_id()),
-                     call->env(),
-                     FlowGraph::kEffect);
-        cid = kDoubleCid;
-      }
-    }
-  } else {
-    // Check if ICDData contains checks with Smi/Null combinations. In that case
-    // we can still emit the optimized Smi equality operation but need to add
-    // checks for null or Smi.
-    GrowableArray<intptr_t> smi_or_null(2);
-    smi_or_null.Add(kSmiCid);
-    smi_or_null.Add(kNullCid);
-    if (ICDataHasOnlyReceiverArgumentClassIds(ic_data,
-                                              smi_or_null,
-                                              smi_or_null)) {
-      const ICData& unary_checks_0 =
-          ICData::ZoneHandle(I, call->ic_data()->AsUnaryClassChecks());
-      AddCheckClass(left,
-                    unary_checks_0,
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-
-      const ICData& unary_checks_1 =
-          ICData::ZoneHandle(I, call->ic_data()->AsUnaryClassChecksForArgNr(1));
-      AddCheckClass(right,
-                    unary_checks_1,
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      cid = kSmiCid;
-    } else {
-      // Shortcut for equality with null.
-      ConstantInstr* right_const = right->AsConstant();
-      ConstantInstr* left_const = left->AsConstant();
-      if ((right_const != NULL && right_const->value().IsNull()) ||
-          (left_const != NULL && left_const->value().IsNull())) {
-        StrictCompareInstr* comp =
-            new(I) StrictCompareInstr(call->token_pos(),
-                                      Token::kEQ_STRICT,
-                                      new(I) Value(left),
-                                      new(I) Value(right),
-                                      false);  // No number check.
-        ReplaceCall(call, comp);
-        return true;
-      }
-      return false;
-    }
-  }
-  ASSERT(cid != kIllegalCid);
-  EqualityCompareInstr* comp = new(I) EqualityCompareInstr(call->token_pos(),
-                                                           op_kind,
-                                                           new(I) Value(left),
-                                                           new(I) Value(right),
-                                                           cid,
-                                                           call->deopt_id());
-  ReplaceCall(call, comp);
-  return true;
-}
-
-
-bool FlowGraphOptimizer::TryReplaceWithRelationalOp(InstanceCallInstr* call,
-                                                    Token::Kind op_kind) {
-  const ICData& ic_data = *call->ic_data();
-  ASSERT(ic_data.NumArgsTested() == 2);
-
-  ASSERT(call->ArgumentCount() == 2);
-  Definition* left = call->ArgumentAt(0);
-  Definition* right = call->ArgumentAt(1);
-
-  intptr_t cid = kIllegalCid;
-  if (HasOnlyTwoOf(ic_data, kSmiCid)) {
-    InsertBefore(call,
-                 new(I) CheckSmiInstr(new(I) Value(left),
-                                      call->deopt_id(),
-                                      call->token_pos()),
-                 call->env(),
-                 FlowGraph::kEffect);
-    InsertBefore(call,
-                 new(I) CheckSmiInstr(new(I) Value(right),
-                                      call->deopt_id(),
-                                      call->token_pos()),
-                 call->env(),
-                 FlowGraph::kEffect);
-    cid = kSmiCid;
-  } else if (HasTwoMintOrSmi(ic_data) &&
-             FlowGraphCompiler::SupportsUnboxedMints()) {
-    cid = kMintCid;
-  } else if (HasTwoDoubleOrSmi(ic_data) && CanUnboxDouble()) {
-    // Use double comparison.
-    if (SmiFitsInDouble()) {
-      cid = kDoubleCid;
-    } else {
-      if (ICDataHasReceiverArgumentClassIds(ic_data, kSmiCid, kSmiCid)) {
-        // We cannot use double comparison on two smis. Need polymorphic
-        // call.
-        return false;
-      } else {
-        InsertBefore(call,
-                     new(I) CheckEitherNonSmiInstr(
-                         new(I) Value(left),
-                         new(I) Value(right),
-                         call->deopt_id()),
-                     call->env(),
-                     FlowGraph::kEffect);
-        cid = kDoubleCid;
-      }
-    }
-  } else {
-    return false;
-  }
-  ASSERT(cid != kIllegalCid);
-  RelationalOpInstr* comp = new(I) RelationalOpInstr(call->token_pos(),
-                                                     op_kind,
-                                                     new(I) Value(left),
-                                                     new(I) Value(right),
-                                                     cid,
-                                                     call->deopt_id());
-  ReplaceCall(call, comp);
-  return true;
-}
-
-
-bool FlowGraphOptimizer::TryReplaceWithBinaryOp(InstanceCallInstr* call,
-                                                Token::Kind op_kind) {
-  intptr_t operands_type = kIllegalCid;
-  ASSERT(call->HasICData());
-  const ICData& ic_data = *call->ic_data();
-  switch (op_kind) {
-    case Token::kADD:
-    case Token::kSUB:
-    case Token::kMUL:
-      if (HasOnlyTwoOf(ic_data, kSmiCid)) {
-        // Don't generate smi code if the IC data is marked because
-        // of an overflow.
-        operands_type = ic_data.HasDeoptReason(ICData::kDeoptBinarySmiOp)
-            ? kMintCid
-            : kSmiCid;
-      } else if (HasTwoMintOrSmi(ic_data) &&
-                 FlowGraphCompiler::SupportsUnboxedMints()) {
-        // Don't generate mint code if the IC data is marked because of an
-        // overflow.
-        if (ic_data.HasDeoptReason(ICData::kDeoptBinaryMintOp)) return false;
-        operands_type = kMintCid;
-      } else if (ShouldSpecializeForDouble(ic_data)) {
-        operands_type = kDoubleCid;
-      } else if (HasOnlyTwoOf(ic_data, kFloat32x4Cid)) {
-        operands_type = kFloat32x4Cid;
-      } else if (HasOnlyTwoOf(ic_data, kInt32x4Cid)) {
-        ASSERT(op_kind != Token::kMUL);  // Int32x4 doesn't have a multiply op.
-        operands_type = kInt32x4Cid;
-      } else if (HasOnlyTwoOf(ic_data, kFloat64x2Cid)) {
-        operands_type = kFloat64x2Cid;
-      } else {
-        return false;
-      }
-      break;
-    case Token::kDIV:
-      if (ShouldSpecializeForDouble(ic_data) ||
-          HasOnlyTwoOf(ic_data, kSmiCid)) {
-        operands_type = kDoubleCid;
-      } else if (HasOnlyTwoOf(ic_data, kFloat32x4Cid)) {
-        operands_type = kFloat32x4Cid;
-      } else if (HasOnlyTwoOf(ic_data, kFloat64x2Cid)) {
-        operands_type = kFloat64x2Cid;
-      } else {
-        return false;
-      }
-      break;
-    case Token::kBIT_AND:
-    case Token::kBIT_OR:
-    case Token::kBIT_XOR:
-      if (HasOnlyTwoOf(ic_data, kSmiCid)) {
-        operands_type = kSmiCid;
-      } else if (HasTwoMintOrSmi(ic_data)) {
-        operands_type = kMintCid;
-      } else if (HasOnlyTwoOf(ic_data, kInt32x4Cid)) {
-        operands_type = kInt32x4Cid;
-      } else {
-        return false;
-      }
-      break;
-    case Token::kSHR:
-    case Token::kSHL:
-      if (HasOnlyTwoOf(ic_data, kSmiCid)) {
-        // Left shift may overflow from smi into mint or big ints.
-        // Don't generate smi code if the IC data is marked because
-        // of an overflow.
-        if (ic_data.HasDeoptReason(ICData::kDeoptBinaryMintOp)) {
-          return false;
-        }
-        operands_type = ic_data.HasDeoptReason(ICData::kDeoptBinarySmiOp)
-            ? kMintCid
-            : kSmiCid;
-      } else if (HasTwoMintOrSmi(ic_data) &&
-                 HasOnlyOneSmi(ICData::Handle(I,
-                     ic_data.AsUnaryClassChecksForArgNr(1)))) {
-        // Don't generate mint code if the IC data is marked because of an
-        // overflow.
-        if (ic_data.HasDeoptReason(ICData::kDeoptBinaryMintOp)) {
-          return false;
-        }
-        // Check for smi/mint << smi or smi/mint >> smi.
-        operands_type = kMintCid;
-      } else {
-        return false;
-      }
-      break;
-    case Token::kMOD:
-    case Token::kTRUNCDIV:
-      if (HasOnlyTwoOf(ic_data, kSmiCid)) {
-        if (ic_data.HasDeoptReason(ICData::kDeoptBinarySmiOp)) {
-          return false;
-        }
-        operands_type = kSmiCid;
-      } else {
-        return false;
-      }
-      break;
-    default:
-      UNREACHABLE();
-  }
-
-  ASSERT(call->ArgumentCount() == 2);
-  Definition* left = call->ArgumentAt(0);
-  Definition* right = call->ArgumentAt(1);
-  if (operands_type == kDoubleCid) {
-    if (!CanUnboxDouble()) {
-      return false;
-    }
-    // Check that either left or right are not a smi.  Result of a
-    // binary operation with two smis is a smi not a double, except '/' which
-    // returns a double for two smis.
-    if (op_kind != Token::kDIV) {
-      InsertBefore(call,
-                   new(I) CheckEitherNonSmiInstr(
-                       new(I) Value(left),
-                       new(I) Value(right),
-                       call->deopt_id()),
-                   call->env(),
-                   FlowGraph::kEffect);
-    }
-
-    BinaryDoubleOpInstr* double_bin_op =
-        new(I) BinaryDoubleOpInstr(op_kind,
-                                   new(I) Value(left),
-                                   new(I) Value(right),
-                                   call->deopt_id(), call->token_pos());
-    ReplaceCall(call, double_bin_op);
-  } else if (operands_type == kMintCid) {
-    if (!FlowGraphCompiler::SupportsUnboxedMints()) return false;
-    if ((op_kind == Token::kSHR) || (op_kind == Token::kSHL)) {
-      ShiftMintOpInstr* shift_op =
-          new(I) ShiftMintOpInstr(
-              op_kind, new(I) Value(left), new(I) Value(right),
-              call->deopt_id());
-      ReplaceCall(call, shift_op);
-    } else {
-      BinaryMintOpInstr* bin_op =
-          new(I) BinaryMintOpInstr(
-              op_kind, new(I) Value(left), new(I) Value(right),
-              call->deopt_id());
-      ReplaceCall(call, bin_op);
-    }
-  } else if (operands_type == kFloat32x4Cid) {
-    return InlineFloat32x4BinaryOp(call, op_kind);
-  } else if (operands_type == kInt32x4Cid) {
-    return InlineInt32x4BinaryOp(call, op_kind);
-  } else if (operands_type == kFloat64x2Cid) {
-    return InlineFloat64x2BinaryOp(call, op_kind);
-  } else if (op_kind == Token::kMOD) {
-    ASSERT(operands_type == kSmiCid);
-    if (right->IsConstant()) {
-      const Object& obj = right->AsConstant()->value();
-      if (obj.IsSmi() && Utils::IsPowerOfTwo(Smi::Cast(obj).Value())) {
-        // Insert smi check and attach a copy of the original environment
-        // because the smi operation can still deoptimize.
-        InsertBefore(call,
-                     new(I) CheckSmiInstr(new(I) Value(left),
-                                          call->deopt_id(),
-                                          call->token_pos()),
-                     call->env(),
-                     FlowGraph::kEffect);
-        ConstantInstr* constant =
-            flow_graph()->GetConstant(Smi::Handle(I,
-                Smi::New(Smi::Cast(obj).Value() - 1)));
-        BinarySmiOpInstr* bin_op =
-            new(I) BinarySmiOpInstr(Token::kBIT_AND,
-                                    new(I) Value(left),
-                                    new(I) Value(constant),
-                                    call->deopt_id());
-        ReplaceCall(call, bin_op);
-        return true;
-      }
-    }
-    // Insert two smi checks and attach a copy of the original
-    // environment because the smi operation can still deoptimize.
-    AddCheckSmi(left, call->deopt_id(), call->env(), call);
-    AddCheckSmi(right, call->deopt_id(), call->env(), call);
-    BinarySmiOpInstr* bin_op =
-        new(I) BinarySmiOpInstr(op_kind,
-                                new(I) Value(left),
-                                new(I) Value(right),
-                                call->deopt_id());
-    ReplaceCall(call, bin_op);
-  } else {
-    ASSERT(operands_type == kSmiCid);
-    // Insert two smi checks and attach a copy of the original
-    // environment because the smi operation can still deoptimize.
-    AddCheckSmi(left, call->deopt_id(), call->env(), call);
-    AddCheckSmi(right, call->deopt_id(), call->env(), call);
-    if (left->IsConstant() &&
-        ((op_kind == Token::kADD) || (op_kind == Token::kMUL))) {
-      // Constant should be on the right side.
-      Definition* temp = left;
-      left = right;
-      right = temp;
-    }
-    BinarySmiOpInstr* bin_op =
-        new(I) BinarySmiOpInstr(
-            op_kind,
-            new(I) Value(left),
-            new(I) Value(right),
-            call->deopt_id());
-    ReplaceCall(call, bin_op);
-  }
-  return true;
-}
-
-
-bool FlowGraphOptimizer::TryReplaceWithUnaryOp(InstanceCallInstr* call,
-                                               Token::Kind op_kind) {
-  ASSERT(call->ArgumentCount() == 1);
-  Definition* input = call->ArgumentAt(0);
-  Definition* unary_op = NULL;
-  if (HasOnlyOneSmi(*call->ic_data())) {
-    InsertBefore(call,
-                 new(I) CheckSmiInstr(new(I) Value(input),
-                                      call->deopt_id(),
-                                      call->token_pos()),
-                 call->env(),
-                 FlowGraph::kEffect);
-    unary_op = new(I) UnarySmiOpInstr(
-        op_kind, new(I) Value(input), call->deopt_id());
-  } else if ((op_kind == Token::kBIT_NOT) &&
-             HasOnlySmiOrMint(*call->ic_data()) &&
-             FlowGraphCompiler::SupportsUnboxedMints()) {
-    unary_op = new(I) UnaryMintOpInstr(
-        op_kind, new(I) Value(input), call->deopt_id());
-  } else if (HasOnlyOneDouble(*call->ic_data()) &&
-             (op_kind == Token::kNEGATE) &&
-             CanUnboxDouble()) {
-    AddReceiverCheck(call);
-    unary_op = new(I) UnaryDoubleOpInstr(
-        Token::kNEGATE, new(I) Value(input), call->deopt_id());
-  } else {
-    return false;
-  }
-  ASSERT(unary_op != NULL);
-  ReplaceCall(call, unary_op);
-  return true;
-}
-
-
-// Using field class
-static RawField* GetField(intptr_t class_id, const String& field_name) {
-  Isolate* isolate = Isolate::Current();
-  Class& cls = Class::Handle(isolate, isolate->class_table()->At(class_id));
-  Field& field = Field::Handle(isolate);
-  while (!cls.IsNull()) {
-    field = cls.LookupInstanceField(field_name);
-    if (!field.IsNull()) {
-      return field.raw();
-    }
-    cls = cls.SuperClass();
-  }
-  return Field::null();
-}
-
-
-// Use CHA to determine if the call needs a class check: if the callee's
-// receiver is the same as the caller's receiver and there are no overriden
-// callee functions, then no class check is needed.
-bool FlowGraphOptimizer::InstanceCallNeedsClassCheck(
-    InstanceCallInstr* call, RawFunction::Kind kind) const {
-  if (!FLAG_use_cha) return true;
-  Definition* callee_receiver = call->ArgumentAt(0);
-  ASSERT(callee_receiver != NULL);
-  const Function& function = flow_graph_->parsed_function()->function();
-  if (function.IsDynamicFunction() &&
-      callee_receiver->IsParameter() &&
-      (callee_receiver->AsParameter()->index() == 0)) {
-    const String& name = (kind == RawFunction::kMethodExtractor)
-        ? String::Handle(I, Field::NameFromGetter(call->function_name()))
-        : call->function_name();
-    return isolate()->cha()->HasOverride(Class::Handle(I, function.Owner()),
-                                         name);
-  }
-  return true;
-}
-
-
-void FlowGraphOptimizer::InlineImplicitInstanceGetter(InstanceCallInstr* call) {
-  ASSERT(call->HasICData());
-  const ICData& ic_data = *call->ic_data();
-  ASSERT(ic_data.HasOneTarget());
-  Function& target = Function::Handle(I);
-  GrowableArray<intptr_t> class_ids;
-  ic_data.GetCheckAt(0, &class_ids, &target);
-  ASSERT(class_ids.length() == 1);
-  // Inline implicit instance getter.
-  const String& field_name =
-      String::Handle(I, Field::NameFromGetter(call->function_name()));
-  const Field& field =
-      Field::ZoneHandle(I, GetField(class_ids[0], field_name));
-  ASSERT(!field.IsNull());
-
-  if (InstanceCallNeedsClassCheck(call, RawFunction::kImplicitGetter)) {
-    AddReceiverCheck(call);
-  }
-  LoadFieldInstr* load = new(I) LoadFieldInstr(
-      new(I) Value(call->ArgumentAt(0)),
-      &field,
-      AbstractType::ZoneHandle(I, field.type()),
-      call->token_pos());
-  load->set_is_immutable(field.is_final());
-  if (field.guarded_cid() != kIllegalCid) {
-    if (!field.is_nullable() || (field.guarded_cid() == kNullCid)) {
-      load->set_result_cid(field.guarded_cid());
-    }
-    FlowGraph::AddToGuardedFields(flow_graph_->guarded_fields(), &field);
-  }
-
-  // Discard the environment from the original instruction because the load
-  // can't deoptimize.
-  call->RemoveEnvironment();
-  ReplaceCall(call, load);
-
-  if (load->result_cid() != kDynamicCid) {
-    // Reset value types if guarded_cid was used.
-    for (Value::Iterator it(load->input_use_list());
-         !it.Done();
-         it.Advance()) {
-      it.Current()->SetReachingType(NULL);
-    }
-  }
-}
-
-
-bool FlowGraphOptimizer::InlineFloat32x4Getter(InstanceCallInstr* call,
-                                               MethodRecognizer::Kind getter) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  AddCheckClass(call->ArgumentAt(0),
-                ICData::ZoneHandle(
-                    I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                call->deopt_id(),
-                call->env(),
-                call);
-  intptr_t mask = 0;
-  if ((getter == MethodRecognizer::kFloat32x4Shuffle) ||
-      (getter == MethodRecognizer::kFloat32x4ShuffleMix)) {
-    // Extract shuffle mask.
-    Definition* mask_definition = NULL;
-    if (getter == MethodRecognizer::kFloat32x4Shuffle) {
-      ASSERT(call->ArgumentCount() == 2);
-      mask_definition = call->ArgumentAt(1);
-    } else {
-      ASSERT(getter == MethodRecognizer::kFloat32x4ShuffleMix);
-      ASSERT(call->ArgumentCount() == 3);
-      mask_definition = call->ArgumentAt(2);
-    }
-    if (!mask_definition->IsConstant()) {
-      return false;
-    }
-    ASSERT(mask_definition->IsConstant());
-    ConstantInstr* constant_instruction = mask_definition->AsConstant();
-    const Object& constant_mask = constant_instruction->value();
-    if (!constant_mask.IsSmi()) {
-      return false;
-    }
-    ASSERT(constant_mask.IsSmi());
-    mask = Smi::Cast(constant_mask).Value();
-    if ((mask < 0) || (mask > 255)) {
-      // Not a valid mask.
-      return false;
-    }
-  }
-  if (getter == MethodRecognizer::kFloat32x4GetSignMask) {
-    Simd32x4GetSignMaskInstr* instr = new(I) Simd32x4GetSignMaskInstr(
-        getter,
-        new(I) Value(call->ArgumentAt(0)),
-        call->deopt_id());
-    ReplaceCall(call, instr);
-    return true;
-  } else if (getter == MethodRecognizer::kFloat32x4ShuffleMix) {
-    Simd32x4ShuffleMixInstr* instr = new(I) Simd32x4ShuffleMixInstr(
-        getter,
-        new(I) Value(call->ArgumentAt(0)),
-        new(I) Value(call->ArgumentAt(1)),
-        mask,
-        call->deopt_id());
-    ReplaceCall(call, instr);
-    return true;
-  } else {
-    ASSERT((getter == MethodRecognizer::kFloat32x4Shuffle)  ||
-           (getter == MethodRecognizer::kFloat32x4ShuffleX) ||
-           (getter == MethodRecognizer::kFloat32x4ShuffleY) ||
-           (getter == MethodRecognizer::kFloat32x4ShuffleZ) ||
-           (getter == MethodRecognizer::kFloat32x4ShuffleW));
-    Simd32x4ShuffleInstr* instr = new(I) Simd32x4ShuffleInstr(
-        getter,
-        new(I) Value(call->ArgumentAt(0)),
-        mask,
-        call->deopt_id());
-    ReplaceCall(call, instr);
-    return true;
-  }
-  UNREACHABLE();
-  return false;
-}
-
-
-bool FlowGraphOptimizer::InlineFloat64x2Getter(InstanceCallInstr* call,
-                                               MethodRecognizer::Kind getter) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  AddCheckClass(call->ArgumentAt(0),
-                ICData::ZoneHandle(
-                    I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                call->deopt_id(),
-                call->env(),
-                call);
-  if ((getter == MethodRecognizer::kFloat64x2GetX) ||
-      (getter == MethodRecognizer::kFloat64x2GetY)) {
-    Simd64x2ShuffleInstr* instr = new(I) Simd64x2ShuffleInstr(
-        getter,
-        new(I) Value(call->ArgumentAt(0)),
-        0,
-        call->deopt_id());
-    ReplaceCall(call, instr);
-    return true;
-  }
-  UNREACHABLE();
-  return false;
-}
-
-
-bool FlowGraphOptimizer::InlineInt32x4Getter(InstanceCallInstr* call,
-                                              MethodRecognizer::Kind getter) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  AddCheckClass(call->ArgumentAt(0),
-                ICData::ZoneHandle(
-                    I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                call->deopt_id(),
-                call->env(),
-                call);
-  intptr_t mask = 0;
-  if ((getter == MethodRecognizer::kInt32x4Shuffle) ||
-      (getter == MethodRecognizer::kInt32x4ShuffleMix)) {
-    // Extract shuffle mask.
-    Definition* mask_definition = NULL;
-    if (getter == MethodRecognizer::kInt32x4Shuffle) {
-      ASSERT(call->ArgumentCount() == 2);
-      mask_definition = call->ArgumentAt(1);
-    } else {
-      ASSERT(getter == MethodRecognizer::kInt32x4ShuffleMix);
-      ASSERT(call->ArgumentCount() == 3);
-      mask_definition = call->ArgumentAt(2);
-    }
-    if (!mask_definition->IsConstant()) {
-      return false;
-    }
-    ASSERT(mask_definition->IsConstant());
-    ConstantInstr* constant_instruction = mask_definition->AsConstant();
-    const Object& constant_mask = constant_instruction->value();
-    if (!constant_mask.IsSmi()) {
-      return false;
-    }
-    ASSERT(constant_mask.IsSmi());
-    mask = Smi::Cast(constant_mask).Value();
-    if ((mask < 0) || (mask > 255)) {
-      // Not a valid mask.
-      return false;
-    }
-  }
-  if (getter == MethodRecognizer::kInt32x4GetSignMask) {
-    Simd32x4GetSignMaskInstr* instr = new(I) Simd32x4GetSignMaskInstr(
-        getter,
-        new(I) Value(call->ArgumentAt(0)),
-        call->deopt_id());
-    ReplaceCall(call, instr);
-    return true;
-  } else if (getter == MethodRecognizer::kInt32x4ShuffleMix) {
-    Simd32x4ShuffleMixInstr* instr = new(I) Simd32x4ShuffleMixInstr(
-        getter,
-        new(I) Value(call->ArgumentAt(0)),
-        new(I) Value(call->ArgumentAt(1)),
-        mask,
-        call->deopt_id());
-    ReplaceCall(call, instr);
-    return true;
-  } else if (getter == MethodRecognizer::kInt32x4Shuffle) {
-    Simd32x4ShuffleInstr* instr = new(I) Simd32x4ShuffleInstr(
-        getter,
-        new(I) Value(call->ArgumentAt(0)),
-        mask,
-        call->deopt_id());
-    ReplaceCall(call, instr);
-    return true;
-  } else {
-    Int32x4GetFlagInstr* instr = new(I) Int32x4GetFlagInstr(
-        getter,
-        new(I) Value(call->ArgumentAt(0)),
-        call->deopt_id());
-    ReplaceCall(call, instr);
-    return true;
-  }
-}
-
-
-bool FlowGraphOptimizer::InlineFloat32x4BinaryOp(InstanceCallInstr* call,
-                                                 Token::Kind op_kind) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  ASSERT(call->ArgumentCount() == 2);
-  Definition* left = call->ArgumentAt(0);
-  Definition* right = call->ArgumentAt(1);
-  // Type check left.
-  AddCheckClass(left,
-                ICData::ZoneHandle(
-                    I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                call->deopt_id(),
-                call->env(),
-                call);
-  // Type check right.
-  AddCheckClass(right,
-                ICData::ZoneHandle(
-                    I, call->ic_data()->AsUnaryClassChecksForArgNr(1)),
-                call->deopt_id(),
-                call->env(),
-                call);
-  // Replace call.
-  BinaryFloat32x4OpInstr* float32x4_bin_op =
-      new(I) BinaryFloat32x4OpInstr(
-          op_kind, new(I) Value(left), new(I) Value(right),
-          call->deopt_id());
-  ReplaceCall(call, float32x4_bin_op);
-
-  return true;
-}
-
-
-bool FlowGraphOptimizer::InlineInt32x4BinaryOp(InstanceCallInstr* call,
-                                                Token::Kind op_kind) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  ASSERT(call->ArgumentCount() == 2);
-  Definition* left = call->ArgumentAt(0);
-  Definition* right = call->ArgumentAt(1);
-  // Type check left.
-  AddCheckClass(left,
-                ICData::ZoneHandle(
-                    I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                call->deopt_id(),
-                call->env(),
-                call);
-  // Type check right.
-  AddCheckClass(right,
-                ICData::ZoneHandle(I,
-                    call->ic_data()->AsUnaryClassChecksForArgNr(1)),
-                call->deopt_id(),
-                call->env(),
-                call);
-  // Replace call.
-  BinaryInt32x4OpInstr* int32x4_bin_op =
-      new(I) BinaryInt32x4OpInstr(
-          op_kind, new(I) Value(left), new(I) Value(right),
-          call->deopt_id());
-  ReplaceCall(call, int32x4_bin_op);
-  return true;
-}
-
-
-bool FlowGraphOptimizer::InlineFloat64x2BinaryOp(InstanceCallInstr* call,
-                                                 Token::Kind op_kind) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  ASSERT(call->ArgumentCount() == 2);
-  Definition* left = call->ArgumentAt(0);
-  Definition* right = call->ArgumentAt(1);
-  // Type check left.
-  AddCheckClass(left,
-                ICData::ZoneHandle(
-                    call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                call->deopt_id(),
-                call->env(),
-                call);
-  // Type check right.
-  AddCheckClass(right,
-                ICData::ZoneHandle(
-                    call->ic_data()->AsUnaryClassChecksForArgNr(1)),
-                call->deopt_id(),
-                call->env(),
-                call);
-  // Replace call.
-  BinaryFloat64x2OpInstr* float64x2_bin_op =
-      new(I) BinaryFloat64x2OpInstr(
-          op_kind, new(I) Value(left), new(I) Value(right),
-          call->deopt_id());
-  ReplaceCall(call, float64x2_bin_op);
-  return true;
-}
-
-
-// Only unique implicit instance getters can be currently handled.
-bool FlowGraphOptimizer::TryInlineInstanceGetter(InstanceCallInstr* call) {
-  ASSERT(call->HasICData());
-  const ICData& ic_data = *call->ic_data();
-  if (ic_data.NumberOfUsedChecks() == 0) {
-    // No type feedback collected.
-    return false;
-  }
-
-  if (!ic_data.HasOneTarget()) {
-    // Polymorphic sites are inlined like normal methods by conventional
-    // inlining in FlowGraphInliner.
-    return false;
-  }
-
-  const Function& target = Function::Handle(I, ic_data.GetTargetAt(0));
-  if (target.kind() != RawFunction::kImplicitGetter) {
-    // Non-implicit getters are inlined like normal methods by conventional
-    // inlining in FlowGraphInliner.
-    return false;
-  }
-  InlineImplicitInstanceGetter(call);
-  return true;
-}
-
-
-bool FlowGraphOptimizer::TryReplaceInstanceCallWithInline(
-    InstanceCallInstr* call) {
-  ASSERT(call->HasICData());
-  Function& target = Function::Handle(I);
-  GrowableArray<intptr_t> class_ids;
-  call->ic_data()->GetCheckAt(0, &class_ids, &target);
-  const intptr_t receiver_cid = class_ids[0];
-
-  TargetEntryInstr* entry;
-  Definition* last;
-  if (!TryInlineRecognizedMethod(receiver_cid,
-                                 target,
-                                 call,
-                                 call->ArgumentAt(0),
-                                 call->token_pos(),
-                                 *call->ic_data(),
-                                 &entry, &last)) {
-    return false;
-  }
-
-  // Insert receiver class check.
-  AddReceiverCheck(call);
-  // Remove the original push arguments.
-  for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
-    PushArgumentInstr* push = call->PushArgumentAt(i);
-    push->ReplaceUsesWith(push->value()->definition());
-    push->RemoveFromGraph();
-  }
-  // Replace all uses of this definition with the result.
-  call->ReplaceUsesWith(last);
-  // Finally insert the sequence other definition in place of this one in the
-  // graph.
-  call->previous()->LinkTo(entry->next());
-  entry->UnuseAllInputs();  // Entry block is not in the graph.
-  last->LinkTo(call);
-  // Remove through the iterator.
-  ASSERT(current_iterator()->Current() == call);
-  current_iterator()->RemoveCurrentFromGraph();
-  call->set_previous(NULL);
-  call->set_next(NULL);
-  return true;
-}
-
-
-// Returns the LoadIndexedInstr.
-Definition* FlowGraphOptimizer::PrepareInlineStringIndexOp(
-    Instruction* call,
-    intptr_t cid,
-    Definition* str,
-    Definition* index,
-    Instruction* cursor) {
-
-  cursor = flow_graph()->AppendTo(cursor,
-                                  new(I) CheckSmiInstr(
-                                      new(I) Value(index),
-                                      call->deopt_id(),
-                                      call->token_pos()),
-                                  call->env(),
-                                  FlowGraph::kEffect);
-
-  // Load the length of the string.
-  // Treat length loads as mutable (i.e. affected by side effects) to avoid
-  // hoisting them since we can't hoist the preceding class-check. This
-  // is because of externalization of strings that affects their class-id.
-  LoadFieldInstr* length = new(I) LoadFieldInstr(
-      new(I) Value(str),
-      String::length_offset(),
-      Type::ZoneHandle(I, Type::SmiType()),
-      str->token_pos());
-  length->set_result_cid(kSmiCid);
-  length->set_recognized_kind(MethodRecognizer::kStringBaseLength);
-
-  cursor = flow_graph()->AppendTo(cursor, length, NULL, FlowGraph::kValue);
-  // Bounds check.
-  cursor = flow_graph()->AppendTo(cursor,
-                                   new(I) CheckArrayBoundInstr(
-                                       new(I) Value(length),
-                                       new(I) Value(index),
-                                       call->deopt_id()),
-                                   call->env(),
-                                   FlowGraph::kEffect);
-
-  LoadIndexedInstr* load_indexed = new(I) LoadIndexedInstr(
-      new(I) Value(str),
-      new(I) Value(index),
-      Instance::ElementSizeFor(cid),
-      cid,
-      Isolate::kNoDeoptId,
-      call->token_pos());
-
-  cursor = flow_graph()->AppendTo(cursor,
-                                  load_indexed,
-                                  NULL,
-                                  FlowGraph::kValue);
-  ASSERT(cursor == load_indexed);
-  return load_indexed;
-}
-
-
-bool FlowGraphOptimizer::InlineStringCodeUnitAt(
-    Instruction* call,
-    intptr_t cid,
-    TargetEntryInstr** entry,
-    Definition** last) {
-  // TODO(johnmccutchan): Handle external strings in PrepareInlineStringIndexOp.
-  if (RawObject::IsExternalStringClassId(cid)) {
-    return false;
-  }
-
-  Definition* str = call->ArgumentAt(0);
-  Definition* index = call->ArgumentAt(1);
-
-  *entry = new(I) TargetEntryInstr(flow_graph()->allocate_block_id(),
-                                   call->GetBlock()->try_index());
-  (*entry)->InheritDeoptTarget(I, call);
-
-  *last = PrepareInlineStringIndexOp(call, cid, str, index, *entry);
-
-  return true;
-}
-
-
-bool FlowGraphOptimizer::InlineStringBaseCharAt(
-    Instruction* call,
-    intptr_t cid,
-    TargetEntryInstr** entry,
-    Definition** last) {
-  // TODO(johnmccutchan): Handle external strings in PrepareInlineStringIndexOp.
-  if (RawObject::IsExternalStringClassId(cid) || cid != kOneByteStringCid) {
-    return false;
-  }
-  Definition* str = call->ArgumentAt(0);
-  Definition* index = call->ArgumentAt(1);
-
-  *entry = new(I) TargetEntryInstr(flow_graph()->allocate_block_id(),
-                                   call->GetBlock()->try_index());
-  (*entry)->InheritDeoptTarget(I, call);
-
-  *last = PrepareInlineStringIndexOp(call, cid, str, index, *entry);
-
-  StringFromCharCodeInstr* char_at = new(I) StringFromCharCodeInstr(
-      new(I) Value(*last), cid);
-
-  flow_graph()->AppendTo(*last, char_at, NULL, FlowGraph::kValue);
-  *last = char_at;
-
-  return true;
-}
-
-
-bool FlowGraphOptimizer::InlineDoubleOp(
-    Token::Kind op_kind,
-    Instruction* call,
-    TargetEntryInstr** entry,
-    Definition** last) {
-  Definition* left = call->ArgumentAt(0);
-  Definition* right = call->ArgumentAt(1);
-
-  *entry = new(I) TargetEntryInstr(flow_graph()->allocate_block_id(),
-                                   call->GetBlock()->try_index());
-  (*entry)->InheritDeoptTarget(I, call);
-  // Arguments are checked. No need for class check.
-  BinaryDoubleOpInstr* double_bin_op =
-      new(I) BinaryDoubleOpInstr(op_kind,
-                                 new(I) Value(left),
-                                 new(I) Value(right),
-                                 call->deopt_id(), call->token_pos());
-  flow_graph()->AppendTo(*entry, double_bin_op, call->env(), FlowGraph::kValue);
-  *last = double_bin_op;
-
-  return true;
-}
-
-
-void FlowGraphOptimizer::ReplaceWithMathCFunction(
-    InstanceCallInstr* call,
-    MethodRecognizer::Kind recognized_kind) {
-  AddReceiverCheck(call);
-  ZoneGrowableArray<Value*>* args =
-      new(I) ZoneGrowableArray<Value*>(call->ArgumentCount());
-  for (intptr_t i = 0; i < call->ArgumentCount(); i++) {
-    args->Add(new(I) Value(call->ArgumentAt(i)));
-  }
-  InvokeMathCFunctionInstr* invoke =
-      new(I) InvokeMathCFunctionInstr(args,
-                                      call->deopt_id(),
-                                      recognized_kind,
-                                      call->token_pos());
-  ReplaceCall(call, invoke);
-}
-
-
-static bool IsSupportedByteArrayViewCid(intptr_t cid) {
-  switch (cid) {
-    case kTypedDataInt8ArrayCid:
-    case kTypedDataUint8ArrayCid:
-    case kExternalTypedDataUint8ArrayCid:
-    case kTypedDataUint8ClampedArrayCid:
-    case kExternalTypedDataUint8ClampedArrayCid:
-    case kTypedDataInt16ArrayCid:
-    case kTypedDataUint16ArrayCid:
-    case kTypedDataInt32ArrayCid:
-    case kTypedDataUint32ArrayCid:
-    case kTypedDataFloat32ArrayCid:
-    case kTypedDataFloat64ArrayCid:
-    case kTypedDataFloat32x4ArrayCid:
-    case kTypedDataInt32x4ArrayCid:
-      return true;
-    default:
-      return false;
-  }
-}
-
-
-// Inline only simple, frequently called core library methods.
-bool FlowGraphOptimizer::TryInlineInstanceMethod(InstanceCallInstr* call) {
-  ASSERT(call->HasICData());
-  const ICData& ic_data = *call->ic_data();
-  if ((ic_data.NumberOfUsedChecks() == 0) || !ic_data.HasOneTarget()) {
-    // No type feedback collected or multiple targets found.
-    return false;
-  }
-
-  Function& target = Function::Handle(I);
-  GrowableArray<intptr_t> class_ids;
-  ic_data.GetCheckAt(0, &class_ids, &target);
-  MethodRecognizer::Kind recognized_kind =
-      MethodRecognizer::RecognizeKind(target);
-
-  if ((recognized_kind == MethodRecognizer::kGrowableArraySetData) &&
-      (ic_data.NumberOfChecks() == 1) &&
-      (class_ids[0] == kGrowableObjectArrayCid)) {
-    // This is an internal method, no need to check argument types.
-    Definition* array = call->ArgumentAt(0);
-    Definition* value = call->ArgumentAt(1);
-    StoreInstanceFieldInstr* store = new(I) StoreInstanceFieldInstr(
-        GrowableObjectArray::data_offset(),
-        new(I) Value(array),
-        new(I) Value(value),
-        kEmitStoreBarrier,
-        call->token_pos());
-    ReplaceCall(call, store);
-    return true;
-  }
-
-  if ((recognized_kind == MethodRecognizer::kGrowableArraySetLength) &&
-      (ic_data.NumberOfChecks() == 1) &&
-      (class_ids[0] == kGrowableObjectArrayCid)) {
-    // This is an internal method, no need to check argument types nor
-    // range.
-    Definition* array = call->ArgumentAt(0);
-    Definition* value = call->ArgumentAt(1);
-    StoreInstanceFieldInstr* store = new(I) StoreInstanceFieldInstr(
-        GrowableObjectArray::length_offset(),
-        new(I) Value(array),
-        new(I) Value(value),
-        kNoStoreBarrier,
-        call->token_pos());
-    ReplaceCall(call, store);
-    return true;
-  }
-
-  if (((recognized_kind == MethodRecognizer::kStringBaseCodeUnitAt) ||
-       (recognized_kind == MethodRecognizer::kStringBaseCharAt)) &&
-      (ic_data.NumberOfChecks() == 1) &&
-      ((class_ids[0] == kOneByteStringCid) ||
-       (class_ids[0] == kTwoByteStringCid))) {
-    return TryReplaceInstanceCallWithInline(call);
-  }
-
-  if ((class_ids[0] == kOneByteStringCid) && (ic_data.NumberOfChecks() == 1)) {
-    if (recognized_kind == MethodRecognizer::kOneByteStringSetAt) {
-      // This is an internal method, no need to check argument types nor
-      // range.
-      Definition* str = call->ArgumentAt(0);
-      Definition* index = call->ArgumentAt(1);
-      Definition* value = call->ArgumentAt(2);
-      StoreIndexedInstr* store_op = new(I) StoreIndexedInstr(
-          new(I) Value(str),
-          new(I) Value(index),
-          new(I) Value(value),
-          kNoStoreBarrier,
-          1,  // Index scale
-          kOneByteStringCid,
-          call->deopt_id(),
-          call->token_pos());
-      ReplaceCall(call, store_op);
-      return true;
-    }
-    return false;
-  }
-
-  if (CanUnboxDouble() &&
-      (recognized_kind == MethodRecognizer::kIntegerToDouble) &&
-      (ic_data.NumberOfChecks() == 1)) {
-    if (class_ids[0] == kSmiCid) {
-      AddReceiverCheck(call);
-      ReplaceCall(call,
-                  new(I) SmiToDoubleInstr(
-                      new(I) Value(call->ArgumentAt(0)),
-                      call->token_pos()));
-      return true;
-    } else if ((class_ids[0] == kMintCid) && CanConvertUnboxedMintToDouble()) {
-      AddReceiverCheck(call);
-      ReplaceCall(call,
-                  new(I) MintToDoubleInstr(new(I) Value(call->ArgumentAt(0)),
-                                           call->deopt_id()));
-      return true;
-    }
-  }
-
-  if (class_ids[0] == kDoubleCid) {
-    if (!CanUnboxDouble()) {
-      return false;
-    }
-    switch (recognized_kind) {
-      case MethodRecognizer::kDoubleToInteger: {
-        AddReceiverCheck(call);
-        ASSERT(call->HasICData());
-        const ICData& ic_data = *call->ic_data();
-        Definition* input = call->ArgumentAt(0);
-        Definition* d2i_instr = NULL;
-        if (ic_data.HasDeoptReason(ICData::kDeoptDoubleToSmi)) {
-          // Do not repeatedly deoptimize because result didn't fit into Smi.
-          d2i_instr =  new(I) DoubleToIntegerInstr(
-              new(I) Value(input), call);
-        } else {
-          // Optimistically assume result fits into Smi.
-          d2i_instr = new(I) DoubleToSmiInstr(
-              new(I) Value(input), call->deopt_id());
-        }
-        ReplaceCall(call, d2i_instr);
-        return true;
-      }
-      case MethodRecognizer::kDoubleMod:
-      case MethodRecognizer::kDoubleRound:
-        ReplaceWithMathCFunction(call, recognized_kind);
-        return true;
-      case MethodRecognizer::kDoubleTruncate:
-      case MethodRecognizer::kDoubleFloor:
-      case MethodRecognizer::kDoubleCeil:
-        if (!TargetCPUFeatures::double_truncate_round_supported()) {
-          ReplaceWithMathCFunction(call, recognized_kind);
-        } else {
-          AddReceiverCheck(call);
-          DoubleToDoubleInstr* d2d_instr =
-              new(I) DoubleToDoubleInstr(new(I) Value(call->ArgumentAt(0)),
-                                         recognized_kind, call->deopt_id());
-          ReplaceCall(call, d2d_instr);
-        }
-        return true;
-      case MethodRecognizer::kDoubleAdd:
-      case MethodRecognizer::kDoubleSub:
-      case MethodRecognizer::kDoubleMul:
-      case MethodRecognizer::kDoubleDiv:
-        return TryReplaceInstanceCallWithInline(call);
-      default:
-        // Unsupported method.
-        return false;
-    }
-  }
-
-  if (IsSupportedByteArrayViewCid(class_ids[0]) &&
-      (ic_data.NumberOfChecks() == 1)) {
-    // For elements that may not fit into a smi on all platforms, check if
-    // elements fit into a smi or the platform supports unboxed mints.
-    if ((recognized_kind == MethodRecognizer::kByteArrayBaseGetInt32) ||
-        (recognized_kind == MethodRecognizer::kByteArrayBaseGetUint32) ||
-        (recognized_kind == MethodRecognizer::kByteArrayBaseSetInt32) ||
-        (recognized_kind == MethodRecognizer::kByteArrayBaseSetUint32)) {
-      if (!CanUnboxInt32()) {
-        return false;
-      }
-    }
-
-    if ((recognized_kind == MethodRecognizer::kByteArrayBaseGetFloat32) ||
-        (recognized_kind == MethodRecognizer::kByteArrayBaseGetFloat64) ||
-        (recognized_kind == MethodRecognizer::kByteArrayBaseSetFloat32) ||
-        (recognized_kind == MethodRecognizer::kByteArrayBaseSetFloat64)) {
-      if (!CanUnboxDouble()) {
-        return false;
-      }
-    }
-
-    switch (recognized_kind) {
-      // ByteArray getters.
-      case MethodRecognizer::kByteArrayBaseGetInt8:
-        return BuildByteArrayViewLoad(call, kTypedDataInt8ArrayCid);
-      case MethodRecognizer::kByteArrayBaseGetUint8:
-        return BuildByteArrayViewLoad(call, kTypedDataUint8ArrayCid);
-      case MethodRecognizer::kByteArrayBaseGetInt16:
-        return BuildByteArrayViewLoad(call, kTypedDataInt16ArrayCid);
-      case MethodRecognizer::kByteArrayBaseGetUint16:
-        return BuildByteArrayViewLoad(call, kTypedDataUint16ArrayCid);
-      case MethodRecognizer::kByteArrayBaseGetInt32:
-        return BuildByteArrayViewLoad(call, kTypedDataInt32ArrayCid);
-      case MethodRecognizer::kByteArrayBaseGetUint32:
-        return BuildByteArrayViewLoad(call, kTypedDataUint32ArrayCid);
-      case MethodRecognizer::kByteArrayBaseGetFloat32:
-        return BuildByteArrayViewLoad(call, kTypedDataFloat32ArrayCid);
-      case MethodRecognizer::kByteArrayBaseGetFloat64:
-        return BuildByteArrayViewLoad(call, kTypedDataFloat64ArrayCid);
-      case MethodRecognizer::kByteArrayBaseGetFloat32x4:
-        return BuildByteArrayViewLoad(call, kTypedDataFloat32x4ArrayCid);
-      case MethodRecognizer::kByteArrayBaseGetInt32x4:
-        return BuildByteArrayViewLoad(call, kTypedDataInt32x4ArrayCid);
-
-      // ByteArray setters.
-      case MethodRecognizer::kByteArrayBaseSetInt8:
-        return BuildByteArrayViewStore(call, kTypedDataInt8ArrayCid);
-      case MethodRecognizer::kByteArrayBaseSetUint8:
-        return BuildByteArrayViewStore(call, kTypedDataUint8ArrayCid);
-      case MethodRecognizer::kByteArrayBaseSetInt16:
-        return BuildByteArrayViewStore(call, kTypedDataInt16ArrayCid);
-      case MethodRecognizer::kByteArrayBaseSetUint16:
-        return BuildByteArrayViewStore(call, kTypedDataUint16ArrayCid);
-      case MethodRecognizer::kByteArrayBaseSetInt32:
-        return BuildByteArrayViewStore(call, kTypedDataInt32ArrayCid);
-      case MethodRecognizer::kByteArrayBaseSetUint32:
-        return BuildByteArrayViewStore(call, kTypedDataUint32ArrayCid);
-      case MethodRecognizer::kByteArrayBaseSetFloat32:
-        return BuildByteArrayViewStore(call, kTypedDataFloat32ArrayCid);
-      case MethodRecognizer::kByteArrayBaseSetFloat64:
-        return BuildByteArrayViewStore(call, kTypedDataFloat64ArrayCid);
-      case MethodRecognizer::kByteArrayBaseSetFloat32x4:
-        return BuildByteArrayViewStore(call, kTypedDataFloat32x4ArrayCid);
-      case MethodRecognizer::kByteArrayBaseSetInt32x4:
-        return BuildByteArrayViewStore(call, kTypedDataInt32x4ArrayCid);
-      default:
-        // Unsupported method.
-        return false;
-    }
-  }
-
-  if ((class_ids[0] == kFloat32x4Cid) && (ic_data.NumberOfChecks() == 1)) {
-    return TryInlineFloat32x4Method(call, recognized_kind);
-  }
-
-  if ((class_ids[0] == kInt32x4Cid) && (ic_data.NumberOfChecks() == 1)) {
-    return TryInlineInt32x4Method(call, recognized_kind);
-  }
-
-  if ((class_ids[0] == kFloat64x2Cid) && (ic_data.NumberOfChecks() == 1)) {
-    return TryInlineFloat64x2Method(call, recognized_kind);
-  }
-
-  if (recognized_kind == MethodRecognizer::kIntegerLeftShiftWithMask32) {
-    ASSERT(call->ArgumentCount() == 3);
-    ASSERT(ic_data.NumArgsTested() == 2);
-    Definition* value = call->ArgumentAt(0);
-    Definition* count = call->ArgumentAt(1);
-    Definition* int32_mask = call->ArgumentAt(2);
-    if (HasOnlyTwoOf(ic_data, kSmiCid)) {
-      if (ic_data.HasDeoptReason(ICData::kDeoptBinaryMintOp)) {
-        return false;
-      }
-      // We cannot overflow. The input value must be a Smi
-      AddCheckSmi(value, call->deopt_id(), call->env(), call);
-      AddCheckSmi(count, call->deopt_id(), call->env(), call);
-      ASSERT(int32_mask->IsConstant());
-      const Integer& mask_literal = Integer::Cast(
-          int32_mask->AsConstant()->value());
-      const int64_t mask_value = mask_literal.AsInt64Value();
-      ASSERT(mask_value >= 0);
-      if (mask_value > Smi::kMaxValue) {
-        // The result will not be Smi.
-        return false;
-      }
-      BinarySmiOpInstr* left_shift =
-          new(I) BinarySmiOpInstr(Token::kSHL,
-                                  new(I) Value(value),
-                                  new(I) Value(count),
-                                  call->deopt_id());
-      left_shift->mark_truncating();
-      if ((kBitsPerWord == 32) && (mask_value == 0xffffffffLL)) {
-        // No BIT_AND operation needed.
-        ReplaceCall(call, left_shift);
-      } else {
-        InsertBefore(call, left_shift, call->env(), FlowGraph::kValue);
-        BinarySmiOpInstr* bit_and =
-            new(I) BinarySmiOpInstr(Token::kBIT_AND,
-                                    new(I) Value(left_shift),
-                                    new(I) Value(int32_mask),
-                                    call->deopt_id());
-        ReplaceCall(call, bit_and);
-      }
-      return true;
-    }
-
-    if (HasTwoMintOrSmi(ic_data) &&
-        HasOnlyOneSmi(ICData::Handle(I,
-                                     ic_data.AsUnaryClassChecksForArgNr(1)))) {
-      if (!FlowGraphCompiler::SupportsUnboxedMints() ||
-          ic_data.HasDeoptReason(ICData::kDeoptBinaryMintOp)) {
-        return false;
-      }
-      ShiftMintOpInstr* left_shift =
-          new(I) ShiftMintOpInstr(Token::kSHL,
-                                  new(I) Value(value),
-                                  new(I) Value(count),
-                                  call->deopt_id());
-      InsertBefore(call, left_shift, call->env(), FlowGraph::kValue);
-      BinaryMintOpInstr* bit_and =
-          new(I) BinaryMintOpInstr(Token::kBIT_AND,
-                                   new(I) Value(left_shift),
-                                   new(I) Value(int32_mask),
-                                   call->deopt_id());
-      ReplaceCall(call, bit_and);
-      return true;
-    }
-  }
-  return false;
-}
-
-
-bool FlowGraphOptimizer::TryInlineFloat32x4Constructor(
-    StaticCallInstr* call,
-    MethodRecognizer::Kind recognized_kind) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  if (recognized_kind == MethodRecognizer::kFloat32x4Zero) {
-    Float32x4ZeroInstr* zero = new(I) Float32x4ZeroInstr();
-    ReplaceCall(call, zero);
-    return true;
-  } else if (recognized_kind == MethodRecognizer::kFloat32x4Splat) {
-    Float32x4SplatInstr* splat =
-        new(I) Float32x4SplatInstr(
-            new(I) Value(call->ArgumentAt(1)), call->deopt_id());
-    ReplaceCall(call, splat);
-    return true;
-  } else if (recognized_kind == MethodRecognizer::kFloat32x4Constructor) {
-    Float32x4ConstructorInstr* con =
-        new(I) Float32x4ConstructorInstr(
-            new(I) Value(call->ArgumentAt(1)),
-            new(I) Value(call->ArgumentAt(2)),
-            new(I) Value(call->ArgumentAt(3)),
-            new(I) Value(call->ArgumentAt(4)),
-            call->deopt_id());
-    ReplaceCall(call, con);
-    return true;
-  } else if (recognized_kind == MethodRecognizer::kFloat32x4FromInt32x4Bits) {
-    Int32x4ToFloat32x4Instr* cast =
-        new(I) Int32x4ToFloat32x4Instr(
-            new(I) Value(call->ArgumentAt(1)), call->deopt_id());
-    ReplaceCall(call, cast);
-    return true;
-  } else if (recognized_kind == MethodRecognizer::kFloat32x4FromFloat64x2) {
-    Float64x2ToFloat32x4Instr* cast =
-        new(I) Float64x2ToFloat32x4Instr(
-            new(I) Value(call->ArgumentAt(1)), call->deopt_id());
-    ReplaceCall(call, cast);
-    return true;
-  }
-  return false;
-}
-
-
-bool FlowGraphOptimizer::TryInlineFloat64x2Constructor(
-    StaticCallInstr* call,
-    MethodRecognizer::Kind recognized_kind) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  if (recognized_kind == MethodRecognizer::kFloat64x2Zero) {
-    Float64x2ZeroInstr* zero = new(I) Float64x2ZeroInstr();
-    ReplaceCall(call, zero);
-    return true;
-  } else if (recognized_kind == MethodRecognizer::kFloat64x2Splat) {
-    Float64x2SplatInstr* splat =
-        new(I) Float64x2SplatInstr(
-            new(I) Value(call->ArgumentAt(1)), call->deopt_id());
-    ReplaceCall(call, splat);
-    return true;
-  } else if (recognized_kind == MethodRecognizer::kFloat64x2Constructor) {
-    Float64x2ConstructorInstr* con =
-        new(I) Float64x2ConstructorInstr(
-            new(I) Value(call->ArgumentAt(1)),
-            new(I) Value(call->ArgumentAt(2)),
-            call->deopt_id());
-    ReplaceCall(call, con);
-    return true;
-  } else if (recognized_kind == MethodRecognizer::kFloat64x2FromFloat32x4) {
-    Float32x4ToFloat64x2Instr* cast =
-        new(I) Float32x4ToFloat64x2Instr(
-            new(I) Value(call->ArgumentAt(1)), call->deopt_id());
-    ReplaceCall(call, cast);
-    return true;
-  }
-  return false;
-}
-
-
-bool FlowGraphOptimizer::TryInlineInt32x4Constructor(
-    StaticCallInstr* call,
-    MethodRecognizer::Kind recognized_kind) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  if (recognized_kind == MethodRecognizer::kInt32x4BoolConstructor) {
-    Int32x4BoolConstructorInstr* con =
-        new(I) Int32x4BoolConstructorInstr(
-            new(I) Value(call->ArgumentAt(1)),
-            new(I) Value(call->ArgumentAt(2)),
-            new(I) Value(call->ArgumentAt(3)),
-            new(I) Value(call->ArgumentAt(4)),
-            call->deopt_id());
-    ReplaceCall(call, con);
-    return true;
-  } else if (recognized_kind == MethodRecognizer::kInt32x4FromFloat32x4Bits) {
-    Float32x4ToInt32x4Instr* cast =
-        new(I) Float32x4ToInt32x4Instr(
-            new(I) Value(call->ArgumentAt(1)), call->deopt_id());
-    ReplaceCall(call, cast);
-    return true;
-  } else if (recognized_kind == MethodRecognizer::kInt32x4Constructor) {
-    Int32x4ConstructorInstr* con =
-        new(I) Int32x4ConstructorInstr(
-            new(I) Value(call->ArgumentAt(1)),
-            new(I) Value(call->ArgumentAt(2)),
-            new(I) Value(call->ArgumentAt(3)),
-            new(I) Value(call->ArgumentAt(4)),
-            call->deopt_id());
-    ReplaceCall(call, con);
-    return true;
-  }
-  return false;
-}
-
-
-bool FlowGraphOptimizer::TryInlineFloat32x4Method(
-    InstanceCallInstr* call,
-    MethodRecognizer::Kind recognized_kind) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  ASSERT(call->HasICData());
-  switch (recognized_kind) {
-    case MethodRecognizer::kFloat32x4ShuffleX:
-    case MethodRecognizer::kFloat32x4ShuffleY:
-    case MethodRecognizer::kFloat32x4ShuffleZ:
-    case MethodRecognizer::kFloat32x4ShuffleW:
-    case MethodRecognizer::kFloat32x4GetSignMask:
-      ASSERT(call->ic_data()->HasReceiverClassId(kFloat32x4Cid));
-      ASSERT(call->ic_data()->HasOneTarget());
-      return InlineFloat32x4Getter(call, recognized_kind);
-
-    case MethodRecognizer::kFloat32x4Equal:
-    case MethodRecognizer::kFloat32x4GreaterThan:
-    case MethodRecognizer::kFloat32x4GreaterThanOrEqual:
-    case MethodRecognizer::kFloat32x4LessThan:
-    case MethodRecognizer::kFloat32x4LessThanOrEqual:
-    case MethodRecognizer::kFloat32x4NotEqual: {
-      Definition* left = call->ArgumentAt(0);
-      Definition* right = call->ArgumentAt(1);
-      // Type check left.
-      AddCheckClass(left,
-                    ICData::ZoneHandle(
-                        I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      // Replace call.
-      Float32x4ComparisonInstr* cmp =
-          new(I) Float32x4ComparisonInstr(recognized_kind,
-                                          new(I) Value(left),
-                                          new(I) Value(right),
-                                          call->deopt_id());
-      ReplaceCall(call, cmp);
-      return true;
-    }
-    case MethodRecognizer::kFloat32x4Min:
-    case MethodRecognizer::kFloat32x4Max: {
-      Definition* left = call->ArgumentAt(0);
-      Definition* right = call->ArgumentAt(1);
-      // Type check left.
-      AddCheckClass(left,
-                    ICData::ZoneHandle(
-                        I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      Float32x4MinMaxInstr* minmax =
-          new(I) Float32x4MinMaxInstr(
-              recognized_kind,
-              new(I) Value(left),
-              new(I) Value(right),
-              call->deopt_id());
-      ReplaceCall(call, minmax);
-      return true;
-    }
-    case MethodRecognizer::kFloat32x4Scale: {
-      Definition* left = call->ArgumentAt(0);
-      Definition* right = call->ArgumentAt(1);
-      // Type check left.
-      AddCheckClass(left,
-                    ICData::ZoneHandle(
-                        I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      // Left and right values are swapped when handed to the instruction,
-      // this is done so that the double value is loaded into the output
-      // register and can be destroyed.
-      Float32x4ScaleInstr* scale =
-          new(I) Float32x4ScaleInstr(recognized_kind,
-                                     new(I) Value(right),
-                                     new(I) Value(left),
-                                     call->deopt_id());
-      ReplaceCall(call, scale);
-      return true;
-    }
-    case MethodRecognizer::kFloat32x4Sqrt:
-    case MethodRecognizer::kFloat32x4ReciprocalSqrt:
-    case MethodRecognizer::kFloat32x4Reciprocal: {
-      Definition* left = call->ArgumentAt(0);
-      AddCheckClass(left,
-                    ICData::ZoneHandle(
-                        I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      Float32x4SqrtInstr* sqrt =
-          new(I) Float32x4SqrtInstr(recognized_kind,
-                                    new(I) Value(left),
-                                    call->deopt_id());
-      ReplaceCall(call, sqrt);
-      return true;
-    }
-    case MethodRecognizer::kFloat32x4WithX:
-    case MethodRecognizer::kFloat32x4WithY:
-    case MethodRecognizer::kFloat32x4WithZ:
-    case MethodRecognizer::kFloat32x4WithW: {
-      Definition* left = call->ArgumentAt(0);
-      Definition* right = call->ArgumentAt(1);
-      // Type check left.
-      AddCheckClass(left,
-                    ICData::ZoneHandle(
-                        I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      Float32x4WithInstr* with = new(I) Float32x4WithInstr(recognized_kind,
-                                                           new(I) Value(left),
-                                                           new(I) Value(right),
-                                                           call->deopt_id());
-      ReplaceCall(call, with);
-      return true;
-    }
-    case MethodRecognizer::kFloat32x4Absolute:
-    case MethodRecognizer::kFloat32x4Negate: {
-      Definition* left = call->ArgumentAt(0);
-      // Type check left.
-      AddCheckClass(left,
-                    ICData::ZoneHandle(
-                        I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      Float32x4ZeroArgInstr* zeroArg =
-          new(I) Float32x4ZeroArgInstr(
-              recognized_kind, new(I) Value(left), call->deopt_id());
-      ReplaceCall(call, zeroArg);
-      return true;
-    }
-    case MethodRecognizer::kFloat32x4Clamp: {
-      Definition* left = call->ArgumentAt(0);
-      Definition* lower = call->ArgumentAt(1);
-      Definition* upper = call->ArgumentAt(2);
-      // Type check left.
-      AddCheckClass(left,
-                    ICData::ZoneHandle(
-                        I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      Float32x4ClampInstr* clamp = new(I) Float32x4ClampInstr(
-          new(I) Value(left),
-          new(I) Value(lower),
-          new(I) Value(upper),
-          call->deopt_id());
-      ReplaceCall(call, clamp);
-      return true;
-    }
-    case MethodRecognizer::kFloat32x4ShuffleMix:
-    case MethodRecognizer::kFloat32x4Shuffle: {
-      return InlineFloat32x4Getter(call, recognized_kind);
-    }
-    default:
-      return false;
-  }
-}
-
-
-bool FlowGraphOptimizer::TryInlineFloat64x2Method(
-    InstanceCallInstr* call,
-    MethodRecognizer::Kind recognized_kind) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  ASSERT(call->HasICData());
-  switch (recognized_kind) {
-    case MethodRecognizer::kFloat64x2GetX:
-    case MethodRecognizer::kFloat64x2GetY:
-      ASSERT(call->ic_data()->HasReceiverClassId(kFloat64x2Cid));
-      ASSERT(call->ic_data()->HasOneTarget());
-      return InlineFloat64x2Getter(call, recognized_kind);
-    case MethodRecognizer::kFloat64x2Negate:
-    case MethodRecognizer::kFloat64x2Abs:
-    case MethodRecognizer::kFloat64x2Sqrt:
-    case MethodRecognizer::kFloat64x2GetSignMask: {
-      Definition* left = call->ArgumentAt(0);
-      // Type check left.
-      AddCheckClass(left,
-                    ICData::ZoneHandle(
-                        I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      Float64x2ZeroArgInstr* zeroArg =
-          new(I) Float64x2ZeroArgInstr(
-              recognized_kind, new(I) Value(left), call->deopt_id());
-      ReplaceCall(call, zeroArg);
-      return true;
-    }
-    case MethodRecognizer::kFloat64x2Scale:
-    case MethodRecognizer::kFloat64x2WithX:
-    case MethodRecognizer::kFloat64x2WithY:
-    case MethodRecognizer::kFloat64x2Min:
-    case MethodRecognizer::kFloat64x2Max: {
-      Definition* left = call->ArgumentAt(0);
-      Definition* right = call->ArgumentAt(1);
-      // Type check left.
-      AddCheckClass(left,
-                    ICData::ZoneHandle(
-                        I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      Float64x2OneArgInstr* zeroArg =
-          new(I) Float64x2OneArgInstr(recognized_kind,
-                                      new(I) Value(left),
-                                      new(I) Value(right),
-                                      call->deopt_id());
-      ReplaceCall(call, zeroArg);
-      return true;
-    }
-    default:
-      return false;
-  }
-}
-
-
-bool FlowGraphOptimizer::TryInlineInt32x4Method(
-    InstanceCallInstr* call,
-    MethodRecognizer::Kind recognized_kind) {
-  if (!ShouldInlineSimd()) {
-    return false;
-  }
-  ASSERT(call->HasICData());
-  switch (recognized_kind) {
-    case MethodRecognizer::kInt32x4ShuffleMix:
-    case MethodRecognizer::kInt32x4Shuffle:
-    case MethodRecognizer::kInt32x4GetFlagX:
-    case MethodRecognizer::kInt32x4GetFlagY:
-    case MethodRecognizer::kInt32x4GetFlagZ:
-    case MethodRecognizer::kInt32x4GetFlagW:
-    case MethodRecognizer::kInt32x4GetSignMask:
-      ASSERT(call->ic_data()->HasReceiverClassId(kInt32x4Cid));
-      ASSERT(call->ic_data()->HasOneTarget());
-      return InlineInt32x4Getter(call, recognized_kind);
-
-    case MethodRecognizer::kInt32x4Select: {
-      Definition* mask = call->ArgumentAt(0);
-      Definition* trueValue = call->ArgumentAt(1);
-      Definition* falseValue = call->ArgumentAt(2);
-      // Type check left.
-      AddCheckClass(mask,
-                    ICData::ZoneHandle(
-                        I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      Int32x4SelectInstr* select = new(I) Int32x4SelectInstr(
-          new(I) Value(mask),
-          new(I) Value(trueValue),
-          new(I) Value(falseValue),
-          call->deopt_id());
-      ReplaceCall(call, select);
-      return true;
-    }
-    case MethodRecognizer::kInt32x4WithFlagX:
-    case MethodRecognizer::kInt32x4WithFlagY:
-    case MethodRecognizer::kInt32x4WithFlagZ:
-    case MethodRecognizer::kInt32x4WithFlagW: {
-      Definition* left = call->ArgumentAt(0);
-      Definition* flag = call->ArgumentAt(1);
-      // Type check left.
-      AddCheckClass(left,
-                    ICData::ZoneHandle(
-                        I, call->ic_data()->AsUnaryClassChecksForArgNr(0)),
-                    call->deopt_id(),
-                    call->env(),
-                    call);
-      Int32x4SetFlagInstr* setFlag = new(I) Int32x4SetFlagInstr(
-          recognized_kind,
-          new(I) Value(left),
-          new(I) Value(flag),
-          call->deopt_id());
-      ReplaceCall(call, setFlag);
-      return true;
-    }
-    default:
-      return false;
-  }
-}
-
-
-bool FlowGraphOptimizer::InlineByteArrayViewLoad(Instruction* call,
-                                                 Definition* receiver,
-                                                 intptr_t array_cid,
-                                                 intptr_t view_cid,
-                                                 const ICData& ic_data,
-                                                 TargetEntryInstr** entry,
-                                                 Definition** last) {
-  ASSERT(array_cid != kIllegalCid);
-  Definition* array = receiver;
-  Definition* index = call->ArgumentAt(1);
-  *entry = new(I) TargetEntryInstr(flow_graph()->allocate_block_id(),
-                                   call->GetBlock()->try_index());
-  (*entry)->InheritDeoptTarget(I, call);
-  Instruction* cursor = *entry;
-
-  array_cid = PrepareInlineByteArrayViewOp(call,
-                                           array_cid,
-                                           view_cid,
-                                           &array,
-                                           index,
-                                           &cursor);
-
-  intptr_t deopt_id = Isolate::kNoDeoptId;
-  if ((array_cid == kTypedDataInt32ArrayCid) ||
-      (array_cid == kTypedDataUint32ArrayCid)) {
-    // Deoptimization may be needed if result does not always fit in a Smi.
-    deopt_id = (kSmiBits >= 32) ? Isolate::kNoDeoptId : call->deopt_id();
-  }
-
-  *last = new(I) LoadIndexedInstr(new(I) Value(array),
-                                  new(I) Value(index),
-                                  1,
-                                  view_cid,
-                                  deopt_id,
-                                  call->token_pos());
-  cursor = flow_graph()->AppendTo(
-      cursor,
-      *last,
-      deopt_id != Isolate::kNoDeoptId ? call->env() : NULL,
-      FlowGraph::kValue);
-
-  if (view_cid == kTypedDataFloat32ArrayCid) {
-    *last = new(I) FloatToDoubleInstr(new(I) Value(*last), deopt_id);
-    flow_graph()->AppendTo(cursor,
-                           *last,
-                           deopt_id != Isolate::kNoDeoptId ? call->env() : NULL,
-                           FlowGraph::kValue);
-  }
-  return true;
-}
-
-
-bool FlowGraphOptimizer::InlineByteArrayViewStore(const Function& target,
-                                                  Instruction* call,
-                                                  Definition* receiver,
-                                                  intptr_t array_cid,
-                                                  intptr_t view_cid,
-                                                  const ICData& ic_data,
-                                                  TargetEntryInstr** entry,
-                                                  Definition** last) {
-  ASSERT(array_cid != kIllegalCid);
-  Definition* array = receiver;
-  Definition* index = call->ArgumentAt(1);
-  *entry = new(I) TargetEntryInstr(flow_graph()->allocate_block_id(),
-                                   call->GetBlock()->try_index());
-  (*entry)->InheritDeoptTarget(I, call);
-  Instruction* cursor = *entry;
-
-  array_cid = PrepareInlineByteArrayViewOp(call,
-                                           array_cid,
-                                           view_cid,
-                                           &array,
-                                           index,
-                                           &cursor);
-
-  // Extract the instance call so we can use the function_name in the stored
-  // value check ICData.
-  InstanceCallInstr* i_call = NULL;
-  if (call->IsPolymorphicInstanceCall()) {
-    i_call = call->AsPolymorphicInstanceCall()->instance_call();
-  } else {
-    ASSERT(call->IsInstanceCall());
-    i_call = call->AsInstanceCall();
-  }
-  ASSERT(i_call != NULL);
-  ICData& value_check = ICData::ZoneHandle(I);
-  switch (view_cid) {
-    case kTypedDataInt8ArrayCid:
-    case kTypedDataUint8ArrayCid:
-    case kTypedDataUint8ClampedArrayCid:
-    case kExternalTypedDataUint8ArrayCid:
-    case kExternalTypedDataUint8ClampedArrayCid:
-    case kTypedDataInt16ArrayCid:
-    case kTypedDataUint16ArrayCid: {
-      // Check that value is always smi.
-      value_check = ICData::New(flow_graph_->parsed_function()->function(),
-                                i_call->function_name(),
-                                Object::empty_array(),  // Dummy args. descr.
-                                Isolate::kNoDeoptId,
-                                1);
-      value_check.AddReceiverCheck(kSmiCid, target);
-      break;
-    }
-    case kTypedDataInt32ArrayCid:
-    case kTypedDataUint32ArrayCid:
-      // On 64-bit platforms assume that stored value is always a smi.
-      if (kSmiBits >= 32) {
-        value_check = ICData::New(flow_graph_->parsed_function()->function(),
-                                  i_call->function_name(),
-                                  Object::empty_array(),  // Dummy args. descr.
-                                  Isolate::kNoDeoptId,
-                                  1);
-        value_check.AddReceiverCheck(kSmiCid, target);
-      }
-      break;
-    case kTypedDataFloat32ArrayCid:
-    case kTypedDataFloat64ArrayCid: {
-      // Check that value is always double.
-      value_check = ICData::New(flow_graph_->parsed_function()->function(),
-                                i_call->function_name(),
-                                Object::empty_array(),  // Dummy args. descr.
-                                Isolate::kNoDeoptId,
-                                1);
-      value_check.AddReceiverCheck(kDoubleCid, target);
-      break;
-    }
-    case kTypedDataInt32x4ArrayCid: {
-      // Check that value is always Int32x4.
-      value_check = ICData::New(flow_graph_->parsed_function()->function(),
-                                i_call->function_name(),
-                                Object::empty_array(),  // Dummy args. descr.
-                                Isolate::kNoDeoptId,
-                                1);
-      value_check.AddReceiverCheck(kInt32x4Cid, target);
-      break;
-    }
-    case kTypedDataFloat32x4ArrayCid: {
-      // Check that value is always Float32x4.
-      value_check = ICData::New(flow_graph_->parsed_function()->function(),
-                                i_call->function_name(),
-                                Object::empty_array(),  // Dummy args. descr.
-                                Isolate::kNoDeoptId,
-                                1);
-      value_check.AddReceiverCheck(kFloat32x4Cid, target);
-      break;
-    }
-    default:
-      // Array cids are already checked in the caller.
-      UNREACHABLE();
-  }
-
-  Definition* stored_value = call->ArgumentAt(2);
-  if (!value_check.IsNull()) {
-    AddCheckClass(stored_value, value_check, call->deopt_id(), call->env(),
-                  call);
-  }
-
-  if (view_cid == kTypedDataFloat32ArrayCid) {
-    stored_value = new(I) DoubleToFloatInstr(
-        new(I) Value(stored_value), call->deopt_id());
-    cursor = flow_graph()->AppendTo(cursor,
-                                    stored_value,
-                                    NULL,
-                                    FlowGraph::kValue);
-  } else if (view_cid == kTypedDataInt32ArrayCid) {
-    stored_value = new(I) UnboxInt32Instr(
-        UnboxInt32Instr::kTruncate,
-        new(I) Value(stored_value),
-        call->deopt_id());
-    cursor = flow_graph()->AppendTo(cursor,
-                                    stored_value,
-                                    call->env(),
-                                    FlowGraph::kValue);
-  } else if (view_cid == kTypedDataUint32ArrayCid) {
-    stored_value = new(I) UnboxUint32Instr(
-        new(I) Value(stored_value),
-        call->deopt_id());
-    ASSERT(stored_value->AsUnboxInteger()->is_truncating());
-    cursor = flow_graph()->AppendTo(cursor,
-                                    stored_value,
-                                    call->env(),
-                                    FlowGraph::kValue);
-  }
-
-  StoreBarrierType needs_store_barrier = kNoStoreBarrier;
-  *last = new(I) StoreIndexedInstr(new(I) Value(array),
-                                   new(I) Value(index),
-                                   new(I) Value(stored_value),
-                                   needs_store_barrier,
-                                   1,  // Index scale
-                                   view_cid,
-                                   call->deopt_id(),
-                                   call->token_pos());
-
-  flow_graph()->AppendTo(cursor,
-                         *last,
-                         call->deopt_id() != Isolate::kNoDeoptId ?
-                            call->env() : NULL,
-                         FlowGraph::kEffect);
-  return true;
-}
-
-
-
-intptr_t FlowGraphOptimizer::PrepareInlineByteArrayViewOp(
-    Instruction* call,
-    intptr_t array_cid,
-    intptr_t view_cid,
-    Definition** array,
-    Definition* byte_index,
-    Instruction** cursor) {
-  // Insert byte_index smi check.
-  *cursor = flow_graph()->AppendTo(*cursor,
-                                   new(I) CheckSmiInstr(
-                                       new(I) Value(byte_index),
-                                       call->deopt_id(),
-                                       call->token_pos()),
-                                   call->env(),
-                                   FlowGraph::kEffect);
-
-  LoadFieldInstr* length =
-      new(I) LoadFieldInstr(
-          new(I) Value(*array),
-          CheckArrayBoundInstr::LengthOffsetFor(array_cid),
-          Type::ZoneHandle(I, Type::SmiType()),
-          call->token_pos());
-  length->set_is_immutable(true);
-  length->set_result_cid(kSmiCid);
-  length->set_recognized_kind(
-      LoadFieldInstr::RecognizedKindFromArrayCid(array_cid));
-  *cursor = flow_graph()->AppendTo(*cursor,
-                                   length,
-                                   NULL,
-                                   FlowGraph::kValue);
-
-  intptr_t element_size = Instance::ElementSizeFor(array_cid);
-  ConstantInstr* bytes_per_element =
-      flow_graph()->GetConstant(Smi::Handle(I, Smi::New(element_size)));
-  BinarySmiOpInstr* len_in_bytes =
-      new(I) BinarySmiOpInstr(Token::kMUL,
-                              new(I) Value(length),
-                              new(I) Value(bytes_per_element),
-                              call->deopt_id());
-  *cursor = flow_graph()->AppendTo(*cursor, len_in_bytes, call->env(),
-                                   FlowGraph::kValue);
-
-  // adjusted_length = len_in_bytes - (element_size - 1).
-  Definition* adjusted_length = len_in_bytes;
-  intptr_t adjustment = Instance::ElementSizeFor(view_cid) - 1;
-  if (adjustment > 0) {
-    ConstantInstr* length_adjustment =
-        flow_graph()->GetConstant(Smi::Handle(I, Smi::New(adjustment)));
-    adjusted_length =
-        new(I) BinarySmiOpInstr(Token::kSUB,
-                                new(I) Value(len_in_bytes),
-                                new(I) Value(length_adjustment),
-                                call->deopt_id());
-    *cursor = flow_graph()->AppendTo(*cursor, adjusted_length, call->env(),
-                                     FlowGraph::kValue);
-  }
-
-  // Check adjusted_length > 0.
-  ConstantInstr* zero =
-      flow_graph()->GetConstant(Smi::Handle(I, Smi::New(0)));
-  *cursor = flow_graph()->AppendTo(*cursor,
-                                   new(I) CheckArrayBoundInstr(
-                                       new(I) Value(adjusted_length),
-                                       new(I) Value(zero),
-                                       call->deopt_id()),
-                                   call->env(),
-                                   FlowGraph::kEffect);
-  // Check 0 <= byte_index < adjusted_length.
-  *cursor = flow_graph()->AppendTo(*cursor,
-                                   new(I) CheckArrayBoundInstr(
-                                       new(I) Value(adjusted_length),
-                                       new(I) Value(byte_index),
-                                       call->deopt_id()),
-                                   call->env(),
-                                   FlowGraph::kEffect);
-
-  if (RawObject::IsExternalTypedDataClassId(array_cid)) {
-    LoadUntaggedInstr* elements =
-        new(I) LoadUntaggedInstr(new(I) Value(*array),
-                                 ExternalTypedData::data_offset());
-    *cursor = flow_graph()->AppendTo(*cursor,
-                                     elements,
-                                     NULL,
-                                     FlowGraph::kValue);
-    *array = elements;
-  }
-  return array_cid;
-}
-
-
-bool FlowGraphOptimizer::BuildByteArrayViewLoad(InstanceCallInstr* call,
-                                                intptr_t view_cid) {
-  const bool simd_view = (view_cid == kTypedDataFloat32x4ArrayCid) ||
-                         (view_cid == kTypedDataInt32x4ArrayCid);
-  const bool float_view = (view_cid == kTypedDataFloat32ArrayCid) ||
-                          (view_cid == kTypedDataFloat64ArrayCid);
-  if (float_view && !CanUnboxDouble()) {
-    return false;
-  }
-  if (simd_view && !ShouldInlineSimd()) {
-    return false;
-  }
-  return TryReplaceInstanceCallWithInline(call);
-}
-
-
-bool FlowGraphOptimizer::BuildByteArrayViewStore(InstanceCallInstr* call,
-                                                 intptr_t view_cid) {
-  const bool simd_view = (view_cid == kTypedDataFloat32x4ArrayCid) ||
-                         (view_cid == kTypedDataInt32x4ArrayCid);
-  const bool float_view = (view_cid == kTypedDataFloat32ArrayCid) ||
-                          (view_cid == kTypedDataFloat64ArrayCid);
-  if (float_view && !CanUnboxDouble()) {
-    return false;
-  }
-  if (simd_view && !ShouldInlineSimd()) {
-    return false;
-  }
-  return TryReplaceInstanceCallWithInline(call);
-}
-
-
-// If type tests specified by 'ic_data' do not depend on type arguments,
-// return mapping cid->result in 'results' (i : cid; i + 1: result).
-// If all tests yield the same result, return it otherwise return Bool::null.
-// If no mapping is possible, 'results' is empty.
-// An instance-of test returning all same results can be converted to a class
-// check.
-RawBool* FlowGraphOptimizer::InstanceOfAsBool(
-    const ICData& ic_data,
-    const AbstractType& type,
-    ZoneGrowableArray<intptr_t>* results) const {
-  ASSERT(results->is_empty());
-  ASSERT(ic_data.NumArgsTested() == 1);  // Unary checks only.
-  if (!type.IsInstantiated() || type.IsMalformedOrMalbounded()) {
-    return Bool::null();
-  }
-  const Class& type_class = Class::Handle(I, type.type_class());
-  const intptr_t num_type_args = type_class.NumTypeArguments();
-  if (num_type_args > 0) {
-    // Only raw types can be directly compared, thus disregarding type
-    // arguments.
-    const intptr_t num_type_params = type_class.NumTypeParameters();
-    const intptr_t from_index = num_type_args - num_type_params;
-    const TypeArguments& type_arguments =
-        TypeArguments::Handle(I, type.arguments());
-    const bool is_raw_type = type_arguments.IsNull() ||
-        type_arguments.IsRaw(from_index, num_type_params);
-    if (!is_raw_type) {
-      // Unknown result.
-      return Bool::null();
-    }
-  }
-
-  const ClassTable& class_table = *isolate()->class_table();
-  Bool& prev = Bool::Handle(I);
-  Class& cls = Class::Handle(I);
-
-  bool results_differ = false;
-  for (int i = 0; i < ic_data.NumberOfChecks(); i++) {
-    cls = class_table.At(ic_data.GetReceiverClassIdAt(i));
-    if (cls.NumTypeArguments() > 0) {
-      return Bool::null();
-    }
-    const bool is_subtype = cls.IsSubtypeOf(
-        TypeArguments::Handle(I),
-        type_class,
-        TypeArguments::Handle(I),
-        NULL);
-    results->Add(cls.id());
-    results->Add(is_subtype);
-    if (prev.IsNull()) {
-      prev = Bool::Get(is_subtype).raw();
-    } else {
-      if (is_subtype != prev.value()) {
-        results_differ = true;
-      }
-    }
-  }
-  return results_differ ?  Bool::null() : prev.raw();
-}
-
-
-// Returns true if checking against this type is a direct class id comparison.
-bool FlowGraphOptimizer::TypeCheckAsClassEquality(const AbstractType& type) {
-  ASSERT(type.IsFinalized() && !type.IsMalformedOrMalbounded());
-  // Requires CHA.
-  if (!FLAG_use_cha) return false;
-  if (!type.IsInstantiated()) return false;
-  const Class& type_class = Class::Handle(type.type_class());
-  // Signature classes have different type checking rules.
-  if (type_class.IsSignatureClass()) return false;
-  // Could be an interface check?
-  if (isolate()->cha()->IsImplemented(type_class)) return false;
-  // Check if there are subclasses.
-  if (isolate()->cha()->HasSubclasses(type_class)) return false;
-  const intptr_t num_type_args = type_class.NumTypeArguments();
-  if (num_type_args > 0) {
-    // Only raw types can be directly compared, thus disregarding type
-    // arguments.
-    const intptr_t num_type_params = type_class.NumTypeParameters();
-    const intptr_t from_index = num_type_args - num_type_params;
-    const TypeArguments& type_arguments =
-        TypeArguments::Handle(type.arguments());
-    const bool is_raw_type = type_arguments.IsNull() ||
-        type_arguments.IsRaw(from_index, num_type_params);
-    return is_raw_type;
-  }
-  return true;
-}
-
-
-static bool CidTestResultsContains(const ZoneGrowableArray<intptr_t>& results,
-                                   intptr_t test_cid) {
-  for (intptr_t i = 0; i < results.length(); i += 2) {
-    if (results[i] == test_cid) return true;
-  }
-  return false;
-}
-
-
-static void TryAddTest(ZoneGrowableArray<intptr_t>* results,
-                       intptr_t test_cid,
-                       bool result) {
-  if (!CidTestResultsContains(*results, test_cid)) {
-    results->Add(test_cid);
-    results->Add(result);
-  }
-}
-
-
-// Tries to add cid tests to 'results' so that no deoptimization is
-// necessary.
-// TODO(srdjan): Do also for other than 'int' type.
-static bool TryExpandTestCidsResult(ZoneGrowableArray<intptr_t>* results,
-                                    const AbstractType& type) {
-  ASSERT(results->length() >= 2);  // At least on eentry.
-  const ClassTable& class_table = *Isolate::Current()->class_table();
-  if ((*results)[0] != kSmiCid) {
-    const Class& cls = Class::Handle(class_table.At(kSmiCid));
-    const Class& type_class = Class::Handle(type.type_class());
-    const bool smi_is_subtype = cls.IsSubtypeOf(TypeArguments::Handle(),
-                                                type_class,
-                                                TypeArguments::Handle(),
-                                                NULL);
-    results->Add((*results)[results->length() - 2]);
-    results->Add((*results)[results->length() - 2]);
-    for (intptr_t i = results->length() - 3; i > 1; --i) {
-      (*results)[i] = (*results)[i - 2];
-    }
-    (*results)[0] = kSmiCid;
-    (*results)[1] = smi_is_subtype;
-  }
-
-  ASSERT(type.IsInstantiated() && !type.IsMalformedOrMalbounded());
-  ASSERT(results->length() >= 2);
-  if (type.IsIntType()) {
-    ASSERT((*results)[0] == kSmiCid);
-    TryAddTest(results, kMintCid, true);
-    TryAddTest(results, kBigintCid, true);
-    // Cannot deoptimize since all tests returning true have been added.
-    return false;
-  }
-
-  return true;  // May deoptimize since we have not identified all 'true' tests.
-}
-
-
-// TODO(srdjan): Use ICData to check if always true or false.
-void FlowGraphOptimizer::ReplaceWithInstanceOf(InstanceCallInstr* call) {
-  ASSERT(Token::IsTypeTestOperator(call->token_kind()));
-  Definition* left = call->ArgumentAt(0);
-  Definition* instantiator = call->ArgumentAt(1);
-  Definition* type_args = call->ArgumentAt(2);
-  const AbstractType& type =
-      AbstractType::Cast(call->ArgumentAt(3)->AsConstant()->value());
-  const bool negate = Bool::Cast(
-      call->ArgumentAt(4)->OriginalDefinition()->AsConstant()->value()).value();
-  const ICData& unary_checks =
-      ICData::ZoneHandle(I, call->ic_data()->AsUnaryClassChecks());
-  if (FLAG_warn_on_javascript_compatibility &&
-      !unary_checks.IssuedJSWarning() &&
-      (type.IsIntType() || type.IsDoubleType() || !type.IsInstantiated())) {
-    // No warning was reported yet for this type check, either because it has
-    // not been executed yet, or because no problematic combinations of instance
-    // type and test type have been encountered so far. A warning may still be
-    // reported, so do not replace the instance call.
-    return;
-  }
-  if (unary_checks.NumberOfChecks() <= FLAG_max_polymorphic_checks) {
-    ZoneGrowableArray<intptr_t>* results =
-        new(I) ZoneGrowableArray<intptr_t>(unary_checks.NumberOfChecks() * 2);
-    Bool& as_bool =
-        Bool::ZoneHandle(I, InstanceOfAsBool(unary_checks, type, results));
-    if (as_bool.IsNull()) {
-      if (results->length() == unary_checks.NumberOfChecks() * 2) {
-        const bool can_deopt = TryExpandTestCidsResult(results, type);
-        TestCidsInstr* test_cids = new(I) TestCidsInstr(
-            call->token_pos(),
-            negate ? Token::kISNOT : Token::kIS,
-            new(I) Value(left),
-            *results,
-            can_deopt ? call->deopt_id() : Isolate::kNoDeoptId);
-        // Remove type.
-        ReplaceCall(call, test_cids);
-        return;
-      }
-    } else {
-      // TODO(srdjan): Use TestCidsInstr also for this case.
-      // One result only.
-      AddReceiverCheck(call);
-      if (negate) {
-        as_bool = Bool::Get(!as_bool.value()).raw();
-      }
-      ConstantInstr* bool_const = flow_graph()->GetConstant(as_bool);
-      for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
-        PushArgumentInstr* push = call->PushArgumentAt(i);
-        push->ReplaceUsesWith(push->value()->definition());
-        push->RemoveFromGraph();
-      }
-      call->ReplaceUsesWith(bool_const);
-      ASSERT(current_iterator()->Current() == call);
-      current_iterator()->RemoveCurrentFromGraph();
-      return;
-    }
-  }
-
-  if (TypeCheckAsClassEquality(type)) {
-    LoadClassIdInstr* left_cid = new(I) LoadClassIdInstr(new(I) Value(left));
-    InsertBefore(call,
-                 left_cid,
-                 NULL,
-                 FlowGraph::kValue);
-    const intptr_t type_cid = Class::Handle(I, type.type_class()).id();
-    ConstantInstr* cid =
-        flow_graph()->GetConstant(Smi::Handle(I, Smi::New(type_cid)));
-
-    StrictCompareInstr* check_cid =
-        new(I) StrictCompareInstr(
-            call->token_pos(),
-            negate ? Token::kNE_STRICT : Token::kEQ_STRICT,
-            new(I) Value(left_cid),
-            new(I) Value(cid),
-            false);  // No number check.
-    ReplaceCall(call, check_cid);
-    return;
-  }
-
-  InstanceOfInstr* instance_of =
-      new(I) InstanceOfInstr(call->token_pos(),
-                             new(I) Value(left),
-                             new(I) Value(instantiator),
-                             new(I) Value(type_args),
-                             type,
-                             negate,
-                             call->deopt_id());
-  ReplaceCall(call, instance_of);
-}
-
-
-// TODO(srdjan): Apply optimizations as in ReplaceWithInstanceOf (TestCids).
-void FlowGraphOptimizer::ReplaceWithTypeCast(InstanceCallInstr* call) {
-  ASSERT(Token::IsTypeCastOperator(call->token_kind()));
-  Definition* left = call->ArgumentAt(0);
-  Definition* instantiator = call->ArgumentAt(1);
-  Definition* type_args = call->ArgumentAt(2);
-  const AbstractType& type =
-      AbstractType::Cast(call->ArgumentAt(3)->AsConstant()->value());
-  ASSERT(!type.IsMalformedOrMalbounded());
-  const ICData& unary_checks =
-      ICData::ZoneHandle(I, call->ic_data()->AsUnaryClassChecks());
-  if (FLAG_warn_on_javascript_compatibility &&
-      !unary_checks.IssuedJSWarning() &&
-      (type.IsIntType() || type.IsDoubleType() || !type.IsInstantiated())) {
-    // No warning was reported yet for this type check, either because it has
-    // not been executed yet, or because no problematic combinations of instance
-    // type and test type have been encountered so far. A warning may still be
-    // reported, so do not replace the instance call.
-    return;
-  }
-  if (unary_checks.NumberOfChecks() <= FLAG_max_polymorphic_checks) {
-    ZoneGrowableArray<intptr_t>* results =
-        new(I) ZoneGrowableArray<intptr_t>(unary_checks.NumberOfChecks() * 2);
-    const Bool& as_bool = Bool::ZoneHandle(I,
-        InstanceOfAsBool(unary_checks, type, results));
-    if (as_bool.raw() == Bool::True().raw()) {
-      AddReceiverCheck(call);
-      // Remove the original push arguments.
-      for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
-        PushArgumentInstr* push = call->PushArgumentAt(i);
-        push->ReplaceUsesWith(push->value()->definition());
-        push->RemoveFromGraph();
-      }
-      // Remove call, replace it with 'left'.
-      call->ReplaceUsesWith(left);
-      ASSERT(current_iterator()->Current() == call);
-      current_iterator()->RemoveCurrentFromGraph();
-      return;
-    }
-  }
-  const String& dst_name = String::ZoneHandle(I,
-      Symbols::New(Exceptions::kCastErrorDstName));
-  AssertAssignableInstr* assert_as =
-      new(I) AssertAssignableInstr(call->token_pos(),
-                                   new(I) Value(left),
-                                   new(I) Value(instantiator),
-                                   new(I) Value(type_args),
-                                   type,
-                                   dst_name,
-                                   call->deopt_id());
-  ReplaceCall(call, assert_as);
-}
-
-
-// Tries to optimize instance call by replacing it with a faster instruction
-// (e.g, binary op, field load, ..).
-void FlowGraphOptimizer::VisitInstanceCall(InstanceCallInstr* instr) {
-  if (!instr->HasICData() || (instr->ic_data()->NumberOfUsedChecks() == 0)) {
-    return;
-  }
-
-  const Token::Kind op_kind = instr->token_kind();
-  // Type test is special as it always gets converted into inlined code.
-  if (Token::IsTypeTestOperator(op_kind)) {
-    ReplaceWithInstanceOf(instr);
-    return;
-  }
-
-  if (Token::IsTypeCastOperator(op_kind)) {
-    ReplaceWithTypeCast(instr);
-    return;
-  }
-
-  const ICData& unary_checks =
-      ICData::ZoneHandle(I, instr->ic_data()->AsUnaryClassChecks());
-
-  const intptr_t max_checks = (op_kind == Token::kEQ)
-      ? FLAG_max_equality_polymorphic_checks
-      : FLAG_max_polymorphic_checks;
-  if ((unary_checks.NumberOfChecks() > max_checks) &&
-      InstanceCallNeedsClassCheck(instr, RawFunction::kRegularFunction)) {
-    // Too many checks, it will be megamorphic which needs unary checks.
-    instr->set_ic_data(&unary_checks);
-    return;
-  }
-
-  if ((op_kind == Token::kASSIGN_INDEX) && TryReplaceWithStoreIndexed(instr)) {
-    return;
-  }
-  if ((op_kind == Token::kINDEX) && TryReplaceWithLoadIndexed(instr)) {
-    return;
-  }
-
-  if (op_kind == Token::kEQ && TryReplaceWithEqualityOp(instr, op_kind)) {
-    return;
-  }
-
-  if (Token::IsRelationalOperator(op_kind) &&
-      TryReplaceWithRelationalOp(instr, op_kind)) {
-    return;
-  }
-
-  if (Token::IsBinaryOperator(op_kind) &&
-      TryReplaceWithBinaryOp(instr, op_kind)) {
-    return;
-  }
-  if (Token::IsUnaryOperator(op_kind) &&
-      TryReplaceWithUnaryOp(instr, op_kind)) {
-    return;
-  }
-  if ((op_kind == Token::kGET) && TryInlineInstanceGetter(instr)) {
-    return;
-  }
-  if ((op_kind == Token::kSET) &&
-      TryInlineInstanceSetter(instr, unary_checks)) {
-    return;
-  }
-  if (TryInlineInstanceMethod(instr)) {
-    return;
-  }
-
-  bool has_one_target = unary_checks.HasOneTarget();
-
-  if (has_one_target) {
-    // Check if the single target is a polymorphic target, if it is,
-    // we don't have one target.
-    const Function& target =
-        Function::Handle(I, unary_checks.GetTargetAt(0));
-    const bool polymorphic_target = MethodRecognizer::PolymorphicTarget(target);
-    has_one_target = !polymorphic_target;
-  }
-
-  if (has_one_target) {
-    RawFunction::Kind function_kind =
-        Function::Handle(I, unary_checks.GetTargetAt(0)).kind();
-    if (!InstanceCallNeedsClassCheck(instr, function_kind)) {
-      const bool call_with_checks = false;
-      PolymorphicInstanceCallInstr* call =
-          new(I) PolymorphicInstanceCallInstr(instr, unary_checks,
-                                              call_with_checks);
-      instr->ReplaceWith(call, current_iterator());
-      return;
-    }
-  }
-
-  if (unary_checks.NumberOfChecks() <= FLAG_max_polymorphic_checks) {
-    bool call_with_checks;
-    if (has_one_target) {
-      // Type propagation has not run yet, we cannot eliminate the check.
-      AddReceiverCheck(instr);
-      // Call can still deoptimize, do not detach environment from instr.
-      call_with_checks = false;
-    } else {
-      call_with_checks = true;
-    }
-    PolymorphicInstanceCallInstr* call =
-        new(I) PolymorphicInstanceCallInstr(instr, unary_checks,
-                                            call_with_checks);
-    instr->ReplaceWith(call, current_iterator());
-  }
-}
-
-
-void FlowGraphOptimizer::VisitStaticCall(StaticCallInstr* call) {
-  if (!CanUnboxDouble()) {
-    return;
-  }
-  MethodRecognizer::Kind recognized_kind =
-      MethodRecognizer::RecognizeKind(call->function());
-  MathUnaryInstr::MathUnaryKind unary_kind;
-  switch (recognized_kind) {
-    case MethodRecognizer::kMathSqrt:
-      unary_kind = MathUnaryInstr::kSqrt;
-      break;
-    case MethodRecognizer::kMathSin:
-      unary_kind = MathUnaryInstr::kSin;
-      break;
-    case MethodRecognizer::kMathCos:
-      unary_kind = MathUnaryInstr::kCos;
-      break;
-    default:
-      unary_kind = MathUnaryInstr::kIllegal;
-      break;
-  }
-  if (unary_kind != MathUnaryInstr::kIllegal) {
-    MathUnaryInstr* math_unary =
-        new(I) MathUnaryInstr(unary_kind,
-                              new(I) Value(call->ArgumentAt(0)),
-                              call->deopt_id());
-    ReplaceCall(call, math_unary);
-  } else if ((recognized_kind == MethodRecognizer::kFloat32x4Zero) ||
-             (recognized_kind == MethodRecognizer::kFloat32x4Splat) ||
-             (recognized_kind == MethodRecognizer::kFloat32x4Constructor) ||
-             (recognized_kind == MethodRecognizer::kFloat32x4FromFloat64x2)) {
-    TryInlineFloat32x4Constructor(call, recognized_kind);
-  } else if ((recognized_kind == MethodRecognizer::kFloat64x2Constructor) ||
-             (recognized_kind == MethodRecognizer::kFloat64x2Zero) ||
-             (recognized_kind == MethodRecognizer::kFloat64x2Splat) ||
-             (recognized_kind == MethodRecognizer::kFloat64x2FromFloat32x4)) {
-    TryInlineFloat64x2Constructor(call, recognized_kind);
-  } else if ((recognized_kind == MethodRecognizer::kInt32x4BoolConstructor) ||
-             (recognized_kind == MethodRecognizer::kInt32x4Constructor)) {
-    TryInlineInt32x4Constructor(call, recognized_kind);
-  } else if (recognized_kind == MethodRecognizer::kObjectConstructor) {
-    // Remove the original push arguments.
-    for (intptr_t i = 0; i < call->ArgumentCount(); ++i) {
-      PushArgumentInstr* push = call->PushArgumentAt(i);
-      push->ReplaceUsesWith(push->value()->definition());
-      push->RemoveFromGraph();
-    }
-    // Manually replace call with global null constant. ReplaceCall can't
-    // be used for definitions that are already in the graph.
-    call->ReplaceUsesWith(flow_graph_->constant_null());
-    ASSERT(current_iterator()->Current() == call);
-    current_iterator()->RemoveCurrentFromGraph();;
-  } else if ((recognized_kind == MethodRecognizer::kMathMin) ||
-             (recognized_kind == MethodRecognizer::kMathMax)) {
-    // We can handle only monomorphic min/max call sites with both arguments
-    // being either doubles or smis.
-    if (call->HasICData() && (call->ic_data()->NumberOfChecks() == 1)) {
-      const ICData& ic_data = *call->ic_data();
-      intptr_t result_cid = kIllegalCid;
-      if (ICDataHasReceiverArgumentClassIds(ic_data, kDoubleCid, kDoubleCid)) {
-        result_cid = kDoubleCid;
-      } else if (ICDataHasReceiverArgumentClassIds(ic_data, kSmiCid, kSmiCid)) {
-        result_cid = kSmiCid;
-      }
-      if (result_cid != kIllegalCid) {
-        MathMinMaxInstr* min_max = new(I) MathMinMaxInstr(
-            recognized_kind,
-            new(I) Value(call->ArgumentAt(0)),
-            new(I) Value(call->ArgumentAt(1)),
-            call->deopt_id(),
-            result_cid);
-        const ICData& unary_checks =
-            ICData::ZoneHandle(I, ic_data.AsUnaryClassChecks());
-        AddCheckClass(min_max->left()->definition(),
-                      unary_checks,
-                      call->deopt_id(),
-                      call->env(),
-                      call);
-        AddCheckClass(min_max->right()->definition(),
-                      unary_checks,
-                      call->deopt_id(),
-                      call->env(),
-                      call);
-        ReplaceCall(call, min_max);
-      }
-    }
-  } else if (recognized_kind == MethodRecognizer::kMathDoublePow) {
-    // We know that first argument is double, the second is num.
-    // InvokeMathCFunctionInstr requires unboxed doubles. UnboxDouble
-    // instructions contain type checks and conversions to double.
-    ZoneGrowableArray<Value*>* args =
-        new(I) ZoneGrowableArray<Value*>(call->ArgumentCount());
-    for (intptr_t i = 0; i < call->ArgumentCount(); i++) {
-      args->Add(new(I) Value(call->ArgumentAt(i)));
-    }
-    InvokeMathCFunctionInstr* invoke =
-        new(I) InvokeMathCFunctionInstr(args,
-                                        call->deopt_id(),
-                                        recognized_kind,
-                                        call->token_pos());
-    ReplaceCall(call, invoke);
-  } else if (recognized_kind == MethodRecognizer::kDoubleFromInteger) {
-    if (call->HasICData() && (call->ic_data()->NumberOfChecks() == 1)) {
-      const ICData& ic_data = *call->ic_data();
-      if (CanUnboxDouble()) {
-        if (ArgIsAlways(kSmiCid, ic_data, 1)) {
-          Definition* arg = call->ArgumentAt(1);
-          AddCheckSmi(arg, call->deopt_id(), call->env(), call);
-          ReplaceCall(call,
-                      new(I) SmiToDoubleInstr(new(I) Value(arg),
-                                              call->token_pos()));
-        } else if (ArgIsAlways(kMintCid, ic_data, 1) &&
-                   CanConvertUnboxedMintToDouble()) {
-          Definition* arg = call->ArgumentAt(1);
-          ReplaceCall(call,
-                      new(I) MintToDoubleInstr(new(I) Value(arg),
-                                               call->deopt_id()));
-        }
-      }
-    }
-  } else if (call->function().IsFactory()) {
-    const Class& function_class =
-        Class::Handle(I, call->function().Owner());
-    if ((function_class.library() == Library::CoreLibrary()) ||
-        (function_class.library() == Library::TypedDataLibrary())) {
-      intptr_t cid = FactoryRecognizer::ResultCid(call->function());
-      switch (cid) {
-        case kArrayCid: {
-          Value* type = new(I) Value(call->ArgumentAt(0));
-          Value* num_elements = new(I) Value(call->ArgumentAt(1));
-          if (num_elements->BindsToConstant() &&
-              num_elements->BoundConstant().IsSmi()) {
-            intptr_t length = Smi::Cast(num_elements->BoundConstant()).Value();
-            if (length >= 0 && length <= Array::kMaxElements) {
-              CreateArrayInstr* create_array =
-                  new(I) CreateArrayInstr(
-                      call->token_pos(), type, num_elements);
-              ReplaceCall(call, create_array);
-            }
-          }
-        }
-        default:
-          break;
-      }
-    }
-  }
-}
-
-
-void FlowGraphOptimizer::VisitStoreInstanceField(
-    StoreInstanceFieldInstr* instr) {
-  if (instr->IsUnboxedStore()) {
-    ASSERT(instr->is_initialization_);
-    // Determine if this field should be unboxed based on the usage of getter
-    // and setter functions: The heuristic requires that the setter has a
-    // usage count of at least 1/kGetterSetterRatio of the getter usage count.
-    // This is to avoid unboxing fields where the setter is never or rarely
-    // executed.
-    const Field& field = Field::ZoneHandle(I, instr->field().raw());
-    const String& field_name = String::Handle(I, field.name());
-    const Class& owner = Class::Handle(I, field.owner());
-    const Function& getter =
-        Function::Handle(I, owner.LookupGetterFunction(field_name));
-    const Function& setter =
-        Function::Handle(I, owner.LookupSetterFunction(field_name));
-    bool result = !getter.IsNull()
-               && !setter.IsNull()
-               && (setter.usage_counter() > 0)
-               && (FLAG_getter_setter_ratio * setter.usage_counter() >=
-                   getter.usage_counter());
-    if (!result) {
-      if (FLAG_trace_optimization) {
-        OS::Print("Disabling unboxing of %s\n", field.ToCString());
-      }
-      field.set_is_unboxing_candidate(false);
-      field.DeoptimizeDependentCode();
-    } else {
-      FlowGraph::AddToGuardedFields(flow_graph_->guarded_fields(), &field);
-    }
-  }
-}
-
-
-void FlowGraphOptimizer::VisitAllocateContext(AllocateContextInstr* instr) {
-  // Replace generic allocation with a sequence of inlined allocation and
-  // explicit initalizing stores.
-  AllocateUninitializedContextInstr* replacement =
-      new AllocateUninitializedContextInstr(instr->token_pos(),
-                                            instr->num_context_variables());
-  instr->ReplaceWith(replacement, current_iterator());
-
-  StoreInstanceFieldInstr* store =
-      new(I) StoreInstanceFieldInstr(Context::parent_offset(),
-                                     new Value(replacement),
-                                     new Value(flow_graph_->constant_null()),
-                                     kNoStoreBarrier,
-                                     instr->token_pos());
-  store->set_is_initialization(true);  // Won't be eliminated by DSE.
-  flow_graph_->InsertAfter(replacement, store, NULL, FlowGraph::kEffect);
-  Definition* cursor = store;
-  for (intptr_t i = 0; i < instr->num_context_variables(); ++i) {
-    store =
-        new(I) StoreInstanceFieldInstr(Context::variable_offset(i),
-                                       new Value(replacement),
-                                       new Value(flow_graph_->constant_null()),
-                                       kNoStoreBarrier,
-                                       instr->token_pos());
-    store->set_is_initialization(true);  // Won't be eliminated by DSE.
-    flow_graph_->InsertAfter(cursor, store, NULL, FlowGraph::kEffect);
-    cursor = store;
-  }
-}
-
-
-void FlowGraphOptimizer::VisitLoadCodeUnits(LoadCodeUnitsInstr* instr) {
-  // TODO(zerny): Use kUnboxedUint32 once it is fully supported/optimized.
-#if defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_ARM)
-  if (!instr->can_pack_into_smi())
-    instr->set_representation(kUnboxedMint);
-#endif
-}
-
-
-bool FlowGraphOptimizer::TryInlineInstanceSetter(InstanceCallInstr* instr,
-                                                 const ICData& unary_ic_data) {
-  ASSERT((unary_ic_data.NumberOfChecks() > 0) &&
-      (unary_ic_data.NumArgsTested() == 1));
-  if (FLAG_enable_type_checks) {
-    // Checked mode setters are inlined like normal methods by conventional
-    // inlining.
-    return false;
-  }
-
-  ASSERT(instr->HasICData());
-  if (unary_ic_data.NumberOfChecks() == 0) {
-    // No type feedback collected.
-    return false;
-  }
-  if (!unary_ic_data.HasOneTarget()) {
-    // Polymorphic sites are inlined like normal method calls by conventional
-    // inlining.
-    return false;
-  }
-  Function& target = Function::Handle(I);
-  intptr_t class_id;
-  unary_ic_data.GetOneClassCheckAt(0, &class_id, &target);
-  if (target.kind() != RawFunction::kImplicitSetter) {
-    // Non-implicit setter are inlined like normal method calls.
-    return false;
-  }
-  // Inline implicit instance setter.
-  const String& field_name =
-      String::Handle(I, Field::NameFromSetter(instr->function_name()));
-  const Field& field =
-      Field::ZoneHandle(I, GetField(class_id, field_name));
-  ASSERT(!field.IsNull());
-
-  if (InstanceCallNeedsClassCheck(instr, RawFunction::kImplicitSetter)) {
-    AddReceiverCheck(instr);
-  }
-  StoreBarrierType needs_store_barrier = kEmitStoreBarrier;
-  if (ArgIsAlways(kSmiCid, *instr->ic_data(), 1)) {
-    InsertBefore(instr,
-                 new(I) CheckSmiInstr(
-                     new(I) Value(instr->ArgumentAt(1)),
-                     instr->deopt_id(),
-                     instr->token_pos()),
-                 instr->env(),
-                 FlowGraph::kEffect);
-    needs_store_barrier = kNoStoreBarrier;
-  }
-
-  if (field.guarded_cid() != kDynamicCid) {
-    InsertBefore(instr,
-                 new(I) GuardFieldClassInstr(
-                     new(I) Value(instr->ArgumentAt(1)),
-                      field,
-                      instr->deopt_id()),
-                 instr->env(),
-                 FlowGraph::kEffect);
-  }
-
-  if (field.needs_length_check()) {
-    InsertBefore(instr,
-                 new(I) GuardFieldLengthInstr(
-                     new(I) Value(instr->ArgumentAt(1)),
-                      field,
-                      instr->deopt_id()),
-                 instr->env(),
-                 FlowGraph::kEffect);
-  }
-
-  // Field guard was detached.
-  StoreInstanceFieldInstr* store = new(I) StoreInstanceFieldInstr(
-      field,
-      new(I) Value(instr->ArgumentAt(0)),
-      new(I) Value(instr->ArgumentAt(1)),
-      needs_store_barrier,
-      instr->token_pos());
-
-  if (store->IsUnboxedStore()) {
-    FlowGraph::AddToGuardedFields(flow_graph_->guarded_fields(), &field);
-  }
-
-  // Discard the environment from the original instruction because the store
-  // can't deoptimize.
-  instr->RemoveEnvironment();
-  ReplaceCall(instr, store);
-  return true;
-}
-
-
-#if defined(TARGET_ARCH_ARM) || defined(TARGET_ARCH_IA32)
-// Smi widening pass is only meaningful on platforms where Smi
-// is smaller than 32bit. For now only support it on ARM and ia32.
-static bool CanBeWidened(BinarySmiOpInstr* smi_op) {
-  return BinaryInt32OpInstr::IsSupported(smi_op->op_kind(),
-                                         smi_op->left(),
-                                         smi_op->right());
-}
-
-
-static bool BenefitsFromWidening(BinarySmiOpInstr* smi_op) {
-  // TODO(vegorov): when shifts with non-constants shift count are supported
-  // add them here as we save untagging for the count.
-  switch (smi_op->op_kind()) {
-    case Token::kMUL:
-    case Token::kSHR:
-      // For kMUL we save untagging of the argument for kSHR
-      // we save tagging of the result.
-      return true;
-
-    default:
-      return false;
-  }
-}
-
-
-void FlowGraphOptimizer::WidenSmiToInt32() {
-  GrowableArray<BinarySmiOpInstr*> candidates;
-
-  // Step 1. Collect all instructions that potentially benefit from widening of
-  // their operands (or their result) into int32 range.
-  for (BlockIterator block_it = flow_graph_->reverse_postorder_iterator();
-       !block_it.Done();
-       block_it.Advance()) {
-    for (ForwardInstructionIterator instr_it(block_it.Current());
-         !instr_it.Done();
-         instr_it.Advance()) {
-      BinarySmiOpInstr* smi_op = instr_it.Current()->AsBinarySmiOp();
-      if ((smi_op != NULL) &&
-          BenefitsFromWidening(smi_op) &&
-          CanBeWidened(smi_op)) {
-        candidates.Add(smi_op);
-      }
-    }
-  }
-
-  if (candidates.is_empty()) {
-    return;
-  }
-
-  // Step 2. For each block in the graph compute which loop it belongs to.
-  // We will use this information later during computation of the widening's
-  // gain: we are going to assume that only conversion occuring inside the
-  // same loop should be counted against the gain, all other conversions
-  // can be hoisted and thus cost nothing compared to the loop cost itself.
-  const ZoneGrowableArray<BlockEntryInstr*>& loop_headers =
-      flow_graph()->LoopHeaders();
-
-  GrowableArray<intptr_t> loops(flow_graph_->preorder().length());
-  for (intptr_t i = 0; i < flow_graph_->preorder().length(); i++) {
-    loops.Add(-1);
-  }
-
-  for (intptr_t loop_id = 0; loop_id < loop_headers.length(); ++loop_id) {
-    for (BitVector::Iterator loop_it(loop_headers[loop_id]->loop_info());
-         !loop_it.Done();
-         loop_it.Advance()) {
-      loops[loop_it.Current()] = loop_id;
-    }
-  }
-
-  // Step 3. For each candidate transitively collect all other BinarySmiOpInstr
-  // and PhiInstr that depend on it and that it depends on and count amount of
-  // untagging operations that we save in assumption that this whole graph of
-  // values is using kUnboxedInt32 representation instead of kTagged.
-  // Convert those graphs that have positive gain to kUnboxedInt32.
-
-  // BitVector containing SSA indexes of all processed definitions. Used to skip
-  // those candidates that belong to dependency graph of another candidate.
-  BitVector* processed =
-      new(I) BitVector(I, flow_graph_->current_ssa_temp_index());
-
-  // Worklist used to collect dependency graph.
-  DefinitionWorklist worklist(flow_graph_, candidates.length());
-  for (intptr_t i = 0; i < candidates.length(); i++) {
-    BinarySmiOpInstr* op = candidates[i];
-    if (op->WasEliminated() || processed->Contains(op->ssa_temp_index())) {
-      continue;
-    }
-
-    if (FLAG_trace_smi_widening) {
-      OS::Print("analysing candidate: %s\n", op->ToCString());
-    }
-    worklist.Clear();
-    worklist.Add(op);
-
-    // Collect dependency graph. Note: more items are added to worklist
-    // inside this loop.
-    intptr_t gain = 0;
-    for (intptr_t j = 0; j < worklist.definitions().length(); j++) {
-      Definition* defn = worklist.definitions()[j];
-
-      if (FLAG_trace_smi_widening) {
-        OS::Print("> %s\n", defn->ToCString());
-      }
-
-      if (defn->IsBinarySmiOp() &&
-          BenefitsFromWidening(defn->AsBinarySmiOp())) {
-        gain++;
-        if (FLAG_trace_smi_widening) {
-          OS::Print("^ [%" Pd "] (o) %s\n", gain, defn->ToCString());
-        }
-      }
-
-      const intptr_t defn_loop = loops[defn->GetBlock()->preorder_number()];
-
-      // Process all inputs.
-      for (intptr_t k = 0; k < defn->InputCount(); k++) {
-        Definition* input = defn->InputAt(k)->definition();
-        if (input->IsBinarySmiOp() &&
-            CanBeWidened(input->AsBinarySmiOp())) {
-          worklist.Add(input);
-        } else if (input->IsPhi() && (input->Type()->ToCid() == kSmiCid)) {
-          worklist.Add(input);
-        } else if (input->IsBinaryMintOp()) {
-          // Mint operation produces untagged result. We avoid tagging.
-          gain++;
-          if (FLAG_trace_smi_widening) {
-            OS::Print("^ [%" Pd "] (i) %s\n", gain, input->ToCString());
-          }
-        } else if (defn_loop == loops[input->GetBlock()->preorder_number()] &&
-                   (input->Type()->ToCid() == kSmiCid)) {
-          // Input comes from the same loop, is known to be smi and requires
-          // untagging.
-          // TODO(vegorov) this heuristic assumes that values that are not
-          // known to be smi have to be checked and this check can be
-          // coalesced with untagging. Start coalescing them.
-          gain--;
-          if (FLAG_trace_smi_widening) {
-            OS::Print("v [%" Pd "] (i) %s\n", gain, input->ToCString());
-          }
-        }
-      }
-
-      // Process all uses.
-      for (Value* use = defn->input_use_list();
-           use != NULL;
-           use = use->next_use()) {
-        Instruction* instr = use->instruction();
-        Definition* use_defn = instr->AsDefinition();
-        if (use_defn == NULL) {
-          // We assume that tagging before returning or pushing argument costs
-          // very little compared to the cost of the return/call itself.
-          if (!instr->IsReturn() && !instr->IsPushArgument()) {
-            gain--;
-            if (FLAG_trace_smi_widening) {
-              OS::Print("v [%" Pd "] (u) %s\n",
-                        gain,
-                        use->instruction()->ToCString());
-            }
-          }
-          continue;
-        } else if (use_defn->IsBinarySmiOp() &&
-                   CanBeWidened(use_defn->AsBinarySmiOp())) {
-          worklist.Add(use_defn);
-        } else if (use_defn->IsPhi() &&
-                   use_defn->AsPhi()->Type()->ToCid() == kSmiCid) {
-          worklist.Add(use_defn);
-        } else if (use_defn->IsBinaryMintOp()) {
-          // BinaryMintOp requires untagging of its inputs.
-          // Converting kUnboxedInt32 to kUnboxedMint is essentially zero cost
-          // sign extension operation.
-          gain++;
-          if (FLAG_trace_smi_widening) {
-            OS::Print("^ [%" Pd "] (u) %s\n",
-                      gain,
-                      use->instruction()->ToCString());
-          }
-        } else if (defn_loop == loops[instr->GetBlock()->preorder_number()]) {
-          gain--;
-          if (FLAG_trace_smi_widening) {
-            OS::Print("v [%" Pd "] (u) %s\n",
-                      gain,
-                      use->instruction()->ToCString());
-          }
-        }
-      }
-    }
-
-    processed->AddAll(worklist.contains_vector());
-
-    if (FLAG_trace_smi_widening) {
-      OS::Print("~ %s gain %" Pd "\n", op->ToCString(), gain);
-    }
-
-    if (gain > 0) {
-      // We have positive gain from widening. Convert all BinarySmiOpInstr into
-      // BinaryInt32OpInstr and set representation of all phis to kUnboxedInt32.
-      for (intptr_t j = 0; j < worklist.definitions().length(); j++) {
-        Definition* defn = worklist.definitions()[j];
-        ASSERT(defn->IsPhi() || defn->IsBinarySmiOp());
-
-        if (defn->IsBinarySmiOp()) {
-          BinarySmiOpInstr* smi_op = defn->AsBinarySmiOp();
-          BinaryInt32OpInstr* int32_op = new(I) BinaryInt32OpInstr(
-            smi_op->op_kind(),
-            smi_op->left()->CopyWithType(),
-            smi_op->right()->CopyWithType(),
-            smi_op->DeoptimizationTarget());
-
-          smi_op->ReplaceWith(int32_op, NULL);
-        } else if (defn->IsPhi()) {
-          defn->AsPhi()->set_representation(kUnboxedInt32);
-          ASSERT(defn->Type()->IsInt());
-        }
-      }
-    }
-  }
-}
-#else
-void FlowGraphOptimizer::WidenSmiToInt32() {
-  // TODO(vegorov) ideally on 64-bit platforms we would like to narrow smi
-  // operations to 32-bit where it saves tagging and untagging and allows
-  // to use shorted (and faster) instructions. But we currently don't
-  // save enough range information in the ICData to drive this decision.
-}
-#endif
-
-void FlowGraphOptimizer::InferIntRanges() {
-  RangeAnalysis range_analysis(flow_graph_);
-  range_analysis.Analyze();
-}
-
-
-void TryCatchAnalyzer::Optimize(FlowGraph* flow_graph) {
-  // For every catch-block: Iterate over all call instructions inside the
-  // corresponding try-block and figure out for each environment value if it
-  // is the same constant at all calls. If yes, replace the initial definition
-  // at the catch-entry with this constant.
-  const GrowableArray<CatchBlockEntryInstr*>& catch_entries =
-      flow_graph->graph_entry()->catch_entries();
-  intptr_t base = kFirstLocalSlotFromFp + flow_graph->num_non_copied_params();
-  for (intptr_t catch_idx = 0;
-       catch_idx < catch_entries.length();
-       ++catch_idx) {
-    CatchBlockEntryInstr* catch_entry = catch_entries[catch_idx];
-
-    // Initialize cdefs with the original initial definitions (ParameterInstr).
-    // The following representation is used:
-    // ParameterInstr => unknown
-    // ConstantInstr => known constant
-    // NULL => non-constant
-    GrowableArray<Definition*>* idefs = catch_entry->initial_definitions();
-    GrowableArray<Definition*> cdefs(idefs->length());
-    cdefs.AddArray(*idefs);
-
-    // exception_var and stacktrace_var are never constant.
-    intptr_t ex_idx = base - catch_entry->exception_var().index();
-    intptr_t st_idx = base - catch_entry->stacktrace_var().index();
-    cdefs[ex_idx] = cdefs[st_idx] = NULL;
-
-    for (BlockIterator block_it = flow_graph->reverse_postorder_iterator();
-         !block_it.Done();
-         block_it.Advance()) {
-      BlockEntryInstr* block = block_it.Current();
-      if (block->try_index() == catch_entry->catch_try_index()) {
-        for (ForwardInstructionIterator instr_it(block);
-             !instr_it.Done();
-             instr_it.Advance()) {
-          Instruction* current = instr_it.Current();
-          if (current->MayThrow()) {
-            Environment* env = current->env()->Outermost();
-            ASSERT(env != NULL);
-            for (intptr_t env_idx = 0; env_idx < cdefs.length(); ++env_idx) {
-              if (cdefs[env_idx] != NULL &&
-                  env->ValueAt(env_idx)->BindsToConstant()) {
-                cdefs[env_idx] = env->ValueAt(env_idx)->definition();
-              }
-              if (cdefs[env_idx] != env->ValueAt(env_idx)->definition()) {
-                cdefs[env_idx] = NULL;
-              }
-            }
-          }
-        }
-      }
-    }
-    for (intptr_t j = 0; j < idefs->length(); ++j) {
-      if (cdefs[j] != NULL && cdefs[j]->IsConstant()) {
-        // TODO(fschneider): Use constants from the constant pool.
-        Definition* old = (*idefs)[j];
-        ConstantInstr* orig = cdefs[j]->AsConstant();
-        ConstantInstr* copy =
-            new(flow_graph->isolate()) ConstantInstr(orig->value());
-        copy->set_ssa_temp_index(flow_graph->alloc_ssa_temp_index());
-        old->ReplaceUsesWith(copy);
-        (*idefs)[j] = copy;
-      }
-    }
-  }
-}
-
-
-LICM::LICM(FlowGraph* flow_graph) : flow_graph_(flow_graph) {
-  ASSERT(flow_graph->is_licm_allowed());
-}
-
-
-void LICM::Hoist(ForwardInstructionIterator* it,
-                 BlockEntryInstr* pre_header,
-                 Instruction* current) {
-  if (current->IsCheckClass()) {
-    current->AsCheckClass()->set_licm_hoisted(true);
-  } else if (current->IsCheckSmi()) {
-    current->AsCheckSmi()->set_licm_hoisted(true);
-  } else if (current->IsCheckEitherNonSmi()) {
-    current->AsCheckEitherNonSmi()->set_licm_hoisted(true);
-  } else if (current->IsCheckArrayBound()) {
-    current->AsCheckArrayBound()->set_licm_hoisted(true);
-  }
-  if (FLAG_trace_optimization) {
-    OS::Print("Hoisting instruction %s:%" Pd " from B%" Pd " to B%" Pd "\n",
-              current->DebugName(),
-              current->GetDeoptId(),
-              current->GetBlock()->block_id(),
-              pre_header->block_id());
-  }
-  // Move the instruction out of the loop.
-  current->RemoveEnvironment();
-  if (it != NULL) {
-    it->RemoveCurrentFromGraph();
-  } else {
-    current->RemoveFromGraph();
-  }
-  GotoInstr* last = pre_header->last_instruction()->AsGoto();
-  // Using kind kEffect will not assign a fresh ssa temporary index.
-  flow_graph()->InsertBefore(last, current, last->env(), FlowGraph::kEffect);
-  current->CopyDeoptIdFrom(*last);
-}
-
-
-void LICM::TrySpecializeSmiPhi(PhiInstr* phi,
-                               BlockEntryInstr* header,
-                               BlockEntryInstr* pre_header) {
-  if (phi->Type()->ToCid() == kSmiCid) {
-    return;
-  }
-
-  // Check if there is only a single kDynamicCid input to the phi that
-  // comes from the pre-header.
-  const intptr_t kNotFound = -1;
-  intptr_t non_smi_input = kNotFound;
-  for (intptr_t i = 0; i < phi->InputCount(); ++i) {
-    Value* input = phi->InputAt(i);
-    if (input->Type()->ToCid() != kSmiCid) {
-      if ((non_smi_input != kNotFound) ||
-          (input->Type()->ToCid() != kDynamicCid)) {
-        // There are multiple kDynamicCid inputs or there is an input that is
-        // known to be non-smi.
-        return;
-      } else {
-        non_smi_input = i;
-      }
-    }
-  }
-
-  if ((non_smi_input == kNotFound) ||
-      (phi->block()->PredecessorAt(non_smi_input) != pre_header)) {
-    return;
-  }
-
-  CheckSmiInstr* check = NULL;
-  for (Value* use = phi->input_use_list();
-       (use != NULL) && (check == NULL);
-       use = use->next_use()) {
-    check = use->instruction()->AsCheckSmi();
-  }
-
-  if (check == NULL) {
-    return;
-  }
-
-  // Host CheckSmi instruction and make this phi smi one.
-  Hoist(NULL, pre_header, check);
-
-  // Replace value we are checking with phi's input.
-  check->value()->BindTo(phi->InputAt(non_smi_input)->definition());
-
-  phi->UpdateType(CompileType::FromCid(kSmiCid));
-}
-
-
-// Load instructions handled by load elimination.
-static bool IsLoadEliminationCandidate(Instruction* instr) {
-  return instr->IsLoadField()
-      || instr->IsLoadIndexed()
-      || instr->IsLoadStaticField();
-}
-
-
-static bool IsLoopInvariantLoad(ZoneGrowableArray<BitVector*>* sets,
-                                intptr_t loop_header_index,
-                                Instruction* instr) {
-  return IsLoadEliminationCandidate(instr) &&
-      (sets != NULL) &&
-      instr->HasPlaceId() &&
-      ((*sets)[loop_header_index] != NULL) &&
-      (*sets)[loop_header_index]->Contains(instr->place_id());
-}
-
-
-void LICM::OptimisticallySpecializeSmiPhis() {
-  if (!flow_graph()->parsed_function()->function().
-          allows_hoisting_check_class()) {
-    // Do not hoist any.
-    return;
-  }
-
-  const ZoneGrowableArray<BlockEntryInstr*>& loop_headers =
-      flow_graph()->LoopHeaders();
-
-  for (intptr_t i = 0; i < loop_headers.length(); ++i) {
-    JoinEntryInstr* header = loop_headers[i]->AsJoinEntry();
-    // Skip loop that don't have a pre-header block.
-    BlockEntryInstr* pre_header = header->ImmediateDominator();
-    if (pre_header == NULL) continue;
-
-    for (PhiIterator it(header); !it.Done(); it.Advance()) {
-      TrySpecializeSmiPhi(it.Current(), header, pre_header);
-    }
-  }
-}
-
-
-void LICM::Optimize() {
-  if (!flow_graph()->parsed_function()->function().
-          allows_hoisting_check_class()) {
-    // Do not hoist any.
-    return;
-  }
-
-  const ZoneGrowableArray<BlockEntryInstr*>& loop_headers =
-      flow_graph()->LoopHeaders();
-
-  ZoneGrowableArray<BitVector*>* loop_invariant_loads =
-      flow_graph()->loop_invariant_loads();
-
-  BlockEffects* block_effects = flow_graph()->block_effects();
-
-  for (intptr_t i = 0; i < loop_headers.length(); ++i) {
-    BlockEntryInstr* header = loop_headers[i];
-    // Skip loop that don't have a pre-header block.
-    BlockEntryInstr* pre_header = header->ImmediateDominator();
-    if (pre_header == NULL) continue;
-
-    for (BitVector::Iterator loop_it(header->loop_info());
-         !loop_it.Done();
-         loop_it.Advance()) {
-      BlockEntryInstr* block = flow_graph()->preorder()[loop_it.Current()];
-      for (ForwardInstructionIterator it(block);
-           !it.Done();
-           it.Advance()) {
-        Instruction* current = it.Current();
-        if ((current->AllowsCSE() &&
-             block_effects->CanBeMovedTo(current, pre_header)) ||
-            IsLoopInvariantLoad(loop_invariant_loads, i, current)) {
-          bool inputs_loop_invariant = true;
-          for (int i = 0; i < current->InputCount(); ++i) {
-            Definition* input_def = current->InputAt(i)->definition();
-            if (!input_def->GetBlock()->Dominates(pre_header)) {
-              inputs_loop_invariant = false;
-              break;
-            }
-          }
-          if (inputs_loop_invariant &&
-              !current->IsAssertAssignable() &&
-              !current->IsAssertBoolean()) {
-            // TODO(fschneider): Enable hoisting of Assert-instructions
-            // if it safe to do.
-            Hoist(&it, pre_header, current);
-          }
-        }
-      }
-    }
-  }
-}
-
-
-// Place describes an abstract location (e.g. field) that IR can load
-// from or store to.
-//
-// Places are also used to describe wild-card locations also known as aliases,
-// that essentially represent sets of places that alias each other. Places A
-// and B are said to alias each other if store into A can affect load from B.
-//
-// We distinguish the following aliases:
-//
-//   - for fields
-//     - *.f, *.@offs - field inside some object;
-//     - X.f, X.@offs - field inside an allocated object X;
-//   - for indexed accesses
-//     - *[*] - non-constant index inside some object;
-//     - *[C] - constant index inside some object;
-//     - X[*] - non-constant index inside an allocated object X;
-//     - X[C] - constant index inside an allocated object X.
-//
-// Separating allocations from other objects improves precision of the
-// load forwarding pass because of the following two properties:
-//
-//   - if X can be proven to have no aliases itself (i.e. there is no other SSA
-//     variable that points to X) then no place inside X can be aliased with any
-//     wildcard dependent place (*.f, *.@offs, *[*], *[C]);
-//   - given allocations X and Y no place inside X can be aliased with any place
-//     inside Y even if any of them or both escape.
-//
-// It important to realize that single place can belong to multiple aliases.
-// For example place X.f with aliased allocation X belongs both to X.f and *.f
-// aliases. Likewise X[C] with non-aliased allocation X belongs to X[C] and X[*]
-// aliases.
-//
-class Place : public ValueObject {
- public:
-  enum Kind {
-    kNone,
-
-    // Field location. For instance fields is represented as a pair of a Field
-    // object and an instance (SSA definition) that is being accessed.
-    // For static fields instance is NULL.
-    kField,
-
-    // VMField location. Represented as a pair of an instance (SSA definition)
-    // being accessed and offset to the field.
-    kVMField,
-
-    // Indexed location with a non-constant index.
-    kIndexed,
-
-    // Indexed location with a constant index.
-    kConstantIndexed,
-  };
-
-  Place(const Place& other)
-      : ValueObject(),
-        kind_(other.kind_),
-        representation_(other.representation_),
-        instance_(other.instance_),
-        raw_selector_(other.raw_selector_),
-        id_(other.id_) {
-  }
-
-  // Construct a place from instruction if instruction accesses any place.
-  // Otherwise constructs kNone place.
-  Place(Instruction* instr, bool* is_load, bool* is_store)
-      : kind_(kNone),
-        representation_(kNoRepresentation),
-        instance_(NULL),
-        raw_selector_(0),
-        id_(0) {
-    switch (instr->tag()) {
-      case Instruction::kLoadField: {
-        LoadFieldInstr* load_field = instr->AsLoadField();
-        representation_ = load_field->representation();
-        instance_ = load_field->instance()->definition()->OriginalDefinition();
-        if (load_field->field() != NULL) {
-          kind_ = kField;
-          field_ = load_field->field();
-        } else {
-          kind_ = kVMField;
-          offset_in_bytes_ = load_field->offset_in_bytes();
-        }
-        *is_load = true;
-        break;
-      }
-
-      case Instruction::kStoreInstanceField: {
-        StoreInstanceFieldInstr* store =
-            instr->AsStoreInstanceField();
-        representation_ = store->RequiredInputRepresentation(
-            StoreInstanceFieldInstr::kValuePos);
-        instance_ = store->instance()->definition()->OriginalDefinition();
-        if (!store->field().IsNull()) {
-          kind_ = kField;
-          field_ = &store->field();
-        } else {
-          kind_ = kVMField;
-          offset_in_bytes_ = store->offset_in_bytes();
-        }
-        *is_store = true;
-        break;
-      }
-
-      case Instruction::kLoadStaticField:
-        kind_ = kField;
-        representation_ = instr->AsLoadStaticField()->representation();
-        field_ = &instr->AsLoadStaticField()->StaticField();
-        *is_load = true;
-        break;
-
-      case Instruction::kStoreStaticField:
-        kind_ = kField;
-        representation_ = instr->AsStoreStaticField()->
-            RequiredInputRepresentation(StoreStaticFieldInstr::kValuePos);
-        field_ = &instr->AsStoreStaticField()->field();
-        *is_store = true;
-        break;
-
-      case Instruction::kLoadIndexed: {
-        LoadIndexedInstr* load_indexed = instr->AsLoadIndexed();
-        representation_ = load_indexed->representation();
-        instance_ = load_indexed->array()->definition()->OriginalDefinition();
-        SetIndex(load_indexed->index()->definition());
-        *is_load = true;
-        break;
-      }
-
-      case Instruction::kStoreIndexed: {
-        StoreIndexedInstr* store_indexed = instr->AsStoreIndexed();
-        representation_ = store_indexed->
-            RequiredInputRepresentation(StoreIndexedInstr::kValuePos);
-        instance_ = store_indexed->array()->definition()->OriginalDefinition();
-        SetIndex(store_indexed->index()->definition());
-        *is_store = true;
-        break;
-      }
-
-      default:
-        break;
-    }
-  }
-
-  // Create object representing *[*] alias.
-  static Place* CreateAnyInstanceAnyIndexAlias(Isolate* isolate,
-                                               intptr_t id) {
-    return Wrap(isolate, Place(kIndexed, NULL, 0), id);
-  }
-
-  // Return least generic alias for this place. Given that aliases are
-  // essentially sets of places we define least generic alias as a smallest
-  // alias that contains this place.
-  //
-  // We obtain such alias by a simple transformation:
-  //
-  //    - for places that depend on an instance X.f, X.@offs, X[i], X[C]
-  //      we drop X if X is not an allocation because in this case X does not
-  //      posess an identity obtaining aliases *.f, *.@offs, *[i] and *[C]
-  //      respectively;
-  //    - for non-constant indexed places X[i] we drop information about the
-  //      index obtaining alias X[*].
-  //
-  Place ToAlias() const {
-    return Place(
-        kind_,
-        (DependsOnInstance() && IsAllocation(instance())) ? instance() : NULL,
-        (kind() == kIndexed) ? 0 : raw_selector_);
-  }
-
-  bool DependsOnInstance() const {
-    switch (kind()) {
-      case kField:
-      case kVMField:
-      case kIndexed:
-      case kConstantIndexed:
-        return true;
-
-      case kNone:
-        return false;
-    }
-
-    UNREACHABLE();
-    return false;
-  }
-
-  // Given instance dependent alias X.f, X.@offs, X[C], X[*] return
-  // wild-card dependent alias *.f, *.@offs, *[C] or *[*] respectively.
-  Place CopyWithoutInstance() const {
-    ASSERT(DependsOnInstance());
-    return Place(kind_, NULL, raw_selector_);
-  }
-
-  // Given alias X[C] or *[C] return X[*] and *[*] respectively.
-  Place CopyWithoutIndex() const {
-    ASSERT(kind_ == kConstantIndexed);
-    return Place(kIndexed, instance_, 0);
-  }
-
-  intptr_t id() const { return id_; }
-
-  Kind kind() const { return kind_; }
-
-  Representation representation() const { return representation_; }
-
-  Definition* instance() const {
-    ASSERT(DependsOnInstance());
-    return instance_;
-  }
-
-  void set_instance(Definition* def) {
-    ASSERT(DependsOnInstance());
-    instance_ = def->OriginalDefinition();
-  }
-
-  const Field& field() const {
-    ASSERT(kind_ == kField);
-    return *field_;
-  }
-
-  intptr_t offset_in_bytes() const {
-    ASSERT(kind_ == kVMField);
-    return offset_in_bytes_;
-  }
-
-  Definition* index() const {
-    ASSERT(kind_ == kIndexed);
-    return index_;
-  }
-
-  intptr_t index_constant() const {
-    ASSERT(kind_ == kConstantIndexed);
-    return index_constant_;
-  }
-
-  static const char* DefinitionName(Definition* def) {
-    if (def == NULL) {
-      return "*";
-    } else {
-      return Isolate::Current()->current_zone()->PrintToString(
-            "v%" Pd, def->ssa_temp_index());
-    }
-  }
-
-  const char* ToCString() const {
-    switch (kind_) {
-      case kNone:
-        return "<none>";
-
-      case kField: {
-        const char* field_name = String::Handle(field().name()).ToCString();
-        if (field().is_static()) {
-          return Isolate::Current()->current_zone()->PrintToString(
-              "<%s>", field_name);
-        } else {
-          return Isolate::Current()->current_zone()->PrintToString(
-              "<%s.%s>", DefinitionName(instance()), field_name);
-        }
-      }
-
-      case kVMField:
-        return Isolate::Current()->current_zone()->PrintToString(
-            "<%s.@%" Pd ">",
-            DefinitionName(instance()),
-            offset_in_bytes());
-
-      case kIndexed:
-        return Isolate::Current()->current_zone()->PrintToString(
-            "<%s[%s]>",
-            DefinitionName(instance()),
-            DefinitionName(index()));
-
-      case kConstantIndexed:
-        return Isolate::Current()->current_zone()->PrintToString(
-            "<%s[%" Pd "]>",
-            DefinitionName(instance()),
-            index_constant());
-    }
-    UNREACHABLE();
-    return "<?>";
-  }
-
-  bool IsFinalField() const {
-    return (kind() == kField) && field().is_final();
-  }
-
-  intptr_t Hashcode() const {
-    return (kind_ * 63 + reinterpret_cast<intptr_t>(instance_)) * 31 +
-        representation_ * 15 + FieldHashcode();
-  }
-
-  bool Equals(const Place* other) const {
-    return (kind_ == other->kind_) &&
-        (representation_ == other->representation_) &&
-        (instance_ == other->instance_) &&
-        SameField(other);
-  }
-
-  // Create a zone allocated copy of this place and assign given id to it.
-  static Place* Wrap(Isolate* isolate, const Place& place, intptr_t id);
-
-  static bool IsAllocation(Definition* defn) {
-    return (defn != NULL) &&
-        (defn->IsAllocateObject() ||
-         defn->IsCreateArray() ||
-         defn->IsAllocateUninitializedContext() ||
-         (defn->IsStaticCall() &&
-          defn->AsStaticCall()->IsRecognizedFactory()));
-  }
-
- private:
-  Place(Kind kind, Definition* instance, intptr_t selector)
-      : kind_(kind),
-        representation_(kNoRepresentation),
-        instance_(instance),
-        raw_selector_(selector),
-        id_(0) {
-  }
-
-  bool SameField(const Place* other) const {
-    return (kind_ == kField) ? (field().raw() == other->field().raw())
-                             : (offset_in_bytes_ == other->offset_in_bytes_);
-  }
-
-  intptr_t FieldHashcode() const {
-    return (kind_ == kField) ? reinterpret_cast<intptr_t>(field().raw())
-                             : offset_in_bytes_;
-  }
-
-  void SetIndex(Definition* index) {
-    ConstantInstr* index_constant = index->AsConstant();
-    if ((index_constant != NULL) && index_constant->value().IsSmi()) {
-      kind_ = kConstantIndexed;
-      index_constant_ = Smi::Cast(index_constant->value()).Value();
-    } else {
-      kind_ = kIndexed;
-      index_ = index;
-    }
-  }
-
-  Kind kind_;
-  Representation representation_;
-  Definition* instance_;
-  union {
-    intptr_t raw_selector_;
-    const Field* field_;
-    intptr_t offset_in_bytes_;
-    intptr_t index_constant_;
-    Definition* index_;
-  };
-
-  intptr_t id_;
-};
-
-
-class ZonePlace : public ZoneAllocated {
- public:
-  explicit ZonePlace(const Place& place) : place_(place) { }
-
-  Place* place() { return &place_; }
-
- private:
-  Place place_;
-};
-
-
-Place* Place::Wrap(Isolate* isolate, const Place& place, intptr_t id) {
-  Place* wrapped = (new(isolate) ZonePlace(place))->place();
-  wrapped->id_ = id;
-  return wrapped;
-}
-
-
-// Correspondence between places connected through outgoing phi moves on the
-// edge that targets join.
-class PhiPlaceMoves : public ZoneAllocated {
- public:
-  // Record a move from the place with id |from| to the place with id |to| at
-  // the given block.
-  void CreateOutgoingMove(Isolate* isolate,
-                          BlockEntryInstr* block, intptr_t from, intptr_t to) {
-    const intptr_t block_num = block->preorder_number();
-    while (moves_.length() <= block_num) {
-      moves_.Add(NULL);
-    }
-
-    if (moves_[block_num] == NULL) {
-      moves_[block_num] = new(isolate) ZoneGrowableArray<Move>(5);
-    }
-
-    moves_[block_num]->Add(Move(from, to));
-  }
-
-  class Move {
-   public:
-    Move(intptr_t from, intptr_t to) : from_(from), to_(to) { }
-
-    intptr_t from() const { return from_; }
-    intptr_t to() const { return to_; }
-
-   private:
-    intptr_t from_;
-    intptr_t to_;
-  };
-
-  typedef const ZoneGrowableArray<Move>* MovesList;
-
-  MovesList GetOutgoingMoves(BlockEntryInstr* block) const {
-    const intptr_t block_num = block->preorder_number();
-    return (block_num < moves_.length()) ?
-        moves_[block_num] : NULL;
-  }
-
- private:
-  GrowableArray<ZoneGrowableArray<Move>* > moves_;
-};
-
-
-// A map from aliases to a set of places sharing the alias. Additionally
-// carries a set of places that can be aliased by side-effects, essentially
-// those that are affected by calls.
-class AliasedSet : public ZoneAllocated {
- public:
-  AliasedSet(Isolate* isolate,
-             DirectChainedHashMap<PointerKeyValueTrait<Place> >* places_map,
-             ZoneGrowableArray<Place*>* places,
-             PhiPlaceMoves* phi_moves)
-      : isolate_(isolate),
-        places_map_(places_map),
-        places_(*places),
-        phi_moves_(phi_moves),
-        aliases_(5),
-        aliases_map_(),
-        representatives_(),
-        killed_(),
-        aliased_by_effects_(new(isolate) BitVector(isolate, places->length())) {
-    InsertAlias(Place::CreateAnyInstanceAnyIndexAlias(isolate_,
-        kAnyInstanceAnyIndexAlias));
-    for (intptr_t i = 0; i < places_.length(); i++) {
-      AddRepresentative(places_[i]);
-    }
-    ComputeKillSets();
-  }
-
-  intptr_t LookupAliasId(const Place& alias) {
-    const Place* result = aliases_map_.Lookup(&alias);
-    return (result != NULL) ? result->id() : static_cast<intptr_t>(kNoAlias);
-  }
-
-  BitVector* GetKilledSet(intptr_t alias) {
-    return (alias < killed_.length()) ? killed_[alias] : NULL;
-  }
-
-  intptr_t max_place_id() const { return places().length(); }
-  bool IsEmpty() const { return max_place_id() == 0; }
-
-  BitVector* aliased_by_effects() const { return aliased_by_effects_; }
-
-  const ZoneGrowableArray<Place*>& places() const {
-    return places_;
-  }
-
-  Place* LookupCanonical(Place* place) const {
-    return places_map_->Lookup(place);
-  }
-
-  void PrintSet(BitVector* set) {
-    bool comma = false;
-    for (BitVector::Iterator it(set);
-         !it.Done();
-         it.Advance()) {
-      if (comma) {
-        OS::Print(", ");
-      }
-      OS::Print("%s", places_[it.Current()]->ToCString());
-      comma = true;
-    }
-  }
-
-  const PhiPlaceMoves* phi_moves() const { return phi_moves_; }
-
-  void RollbackAliasedIdentites() {
-    for (intptr_t i = 0; i < identity_rollback_.length(); ++i) {
-      identity_rollback_[i]->SetIdentity(AliasIdentity::Unknown());
-    }
-  }
-
-  // Returns false if the result of an allocation instruction can't be aliased
-  // by another SSA variable and true otherwise.
-  bool CanBeAliased(Definition* alloc) {
-    if (!Place::IsAllocation(alloc)) {
-      return true;
-    }
-
-    if (alloc->Identity().IsUnknown()) {
-      ComputeAliasing(alloc);
-    }
-
-    return !alloc->Identity().IsNotAliased();
-  }
-
-  enum {
-    kNoAlias = 0
-  };
-
- private:
-  enum {
-    // Artificial alias that is used to collect all representatives of the
-    // *[C], X[C] aliases for arbitrary C.
-    kAnyConstantIndexedAlias = 1,
-
-    // Artificial alias that is used to collect all representatives of
-    // *[C] alias for arbitrary C.
-    kUnknownInstanceConstantIndexedAlias = 2,
-
-    // Artificial alias that is used to collect all representatives of
-    // X[*] alias for all X.
-    kAnyAllocationIndexedAlias = 3,
-
-    // *[*] alias.
-    kAnyInstanceAnyIndexAlias = 4
-  };
-
-  // Compute least generic alias for the place and assign alias id to it.
-  void AddRepresentative(Place* place) {
-    if (!place->IsFinalField()) {
-      const Place* alias = CanonicalizeAlias(place->ToAlias());
-      EnsureSet(&representatives_, alias->id())->Add(place->id());
-
-      // Update cumulative representative sets that are used during
-      // killed sets computation.
-      if (alias->kind() == Place::kConstantIndexed) {
-        if (CanBeAliased(alias->instance())) {
-          EnsureSet(&representatives_, kAnyConstantIndexedAlias)->
-              Add(place->id());
-        }
-
-        if (alias->instance() == NULL) {
-          EnsureSet(&representatives_, kUnknownInstanceConstantIndexedAlias)->
-              Add(place->id());
-        }
-      } else if ((alias->kind() == Place::kIndexed) &&
-                 CanBeAliased(place->instance())) {
-        EnsureSet(&representatives_, kAnyAllocationIndexedAlias)->
-            Add(place->id());
-      }
-
-      if (!IsIndependentFromEffects(place)) {
-        aliased_by_effects_->Add(place->id());
-      }
-    }
-  }
-
-  void ComputeKillSets() {
-    for (intptr_t i = 0; i < aliases_.length(); ++i) {
-      const Place* alias = aliases_[i];
-      // Add all representatives to the kill set.
-      AddAllRepresentatives(alias->id(), alias->id());
-      ComputeKillSet(alias);
-    }
-
-    if (FLAG_trace_load_optimization) {
-      OS::Print("Aliases KILL sets:\n");
-      for (intptr_t i = 0; i < aliases_.length(); ++i) {
-        const Place* alias = aliases_[i];
-        BitVector* kill = GetKilledSet(alias->id());
-
-        OS::Print("%s: ", alias->ToCString());
-        if (kill != NULL) {
-          PrintSet(kill);
-        }
-        OS::Print("\n");
-      }
-    }
-  }
-
-  void InsertAlias(const Place* alias) {
-    aliases_map_.Insert(alias);
-    aliases_.Add(alias);
-  }
-
-  const Place* CanonicalizeAlias(const Place& alias) {
-    const Place* canonical = aliases_map_.Lookup(&alias);
-    if (canonical == NULL) {
-      canonical = Place::Wrap(isolate_,
-                              alias,
-                              kAnyInstanceAnyIndexAlias + aliases_.length());
-      InsertAlias(canonical);
-    }
-    return canonical;
-  }
-
-  BitVector* GetRepresentativesSet(intptr_t alias) {
-    return (alias < representatives_.length()) ? representatives_[alias] : NULL;
-  }
-
-  BitVector* EnsureSet(GrowableArray<BitVector*>* sets,
-                       intptr_t alias) {
-    while (sets->length() <= alias) {
-      sets->Add(NULL);
-    }
-
-    BitVector* set = (*sets)[alias];
-    if (set == NULL) {
-      (*sets)[alias] = set = new(isolate_) BitVector(isolate_, max_place_id());
-    }
-    return set;
-  }
-
-  void AddAllRepresentatives(const Place* to, intptr_t from) {
-    AddAllRepresentatives(to->id(), from);
-  }
-
-  void AddAllRepresentatives(intptr_t to, intptr_t from) {
-    BitVector* from_set = GetRepresentativesSet(from);
-    if (from_set != NULL) {
-      EnsureSet(&killed_, to)->AddAll(from_set);
-    }
-  }
-
-  void CrossAlias(const Place* to, const Place& from) {
-    const intptr_t from_id = LookupAliasId(from);
-    if (from_id == kNoAlias) {
-      return;
-    }
-    CrossAlias(to, from_id);
-  }
-
-  void CrossAlias(const Place* to, intptr_t from) {
-    AddAllRepresentatives(to->id(), from);
-    AddAllRepresentatives(from, to->id());
-  }
-
-  // When computing kill sets we let less generic alias insert its
-  // representatives into more generic alias'es kill set. For example
-  // when visiting alias X[*] instead of searching for all aliases X[C]
-  // and inserting their representatives into kill set for X[*] we update
-  // kill set for X[*] each time we visit new X[C] for some C.
-  // There is an exception however: if both aliases are parametric like *[C]
-  // and X[*] which cross alias when X is an aliased allocation then we use
-  // artificial aliases that contain all possible representatives for the given
-  // alias for any value of the parameter to compute resulting kill set.
-  void ComputeKillSet(const Place* alias) {
-    switch (alias->kind()) {
-      case Place::kIndexed:  // Either *[*] or X[*] alias.
-        if (alias->instance() == NULL) {
-          // *[*] aliases with X[*], X[C], *[C].
-          AddAllRepresentatives(alias, kAnyConstantIndexedAlias);
-          AddAllRepresentatives(alias, kAnyAllocationIndexedAlias);
-        } else if (CanBeAliased(alias->instance())) {
-          // X[*] aliases with X[C].
-          // If X can be aliased then X[*] also aliases with *[C], *[*].
-          CrossAlias(alias, kAnyInstanceAnyIndexAlias);
-          AddAllRepresentatives(alias, kUnknownInstanceConstantIndexedAlias);
-        }
-        break;
-
-      case Place::kConstantIndexed:  // Either X[C] or *[C] alias.
-        if (alias->instance() == NULL) {
-          // *[C] aliases with X[C], X[*], *[*].
-          AddAllRepresentatives(alias, kAnyAllocationIndexedAlias);
-          CrossAlias(alias, kAnyInstanceAnyIndexAlias);
-        } else {
-          // X[C] aliases with X[*].
-          // If X can be aliased then X[C] also aliases with *[C], *[*].
-          CrossAlias(alias, alias->CopyWithoutIndex());
-          if (CanBeAliased(alias->instance())) {
-            CrossAlias(alias, alias->CopyWithoutInstance());
-            CrossAlias(alias, kAnyInstanceAnyIndexAlias);
-          }
-        }
-        break;
-
-      case Place::kField:
-      case Place::kVMField:
-        if (CanBeAliased(alias->instance())) {
-          // X.f or X.@offs alias with *.f and *.@offs respectively.
-          CrossAlias(alias, alias->CopyWithoutInstance());
-        }
-        break;
-
-      case Place::kNone:
-        UNREACHABLE();
-    }
-  }
-
-  // Returns true if the given load is unaffected by external side-effects.
-  // This essentially means that no stores to the same location can
-  // occur in other functions.
-  bool IsIndependentFromEffects(Place* place) {
-    if (place->IsFinalField()) {
-      // Note that we can't use LoadField's is_immutable attribute here because
-      // some VM-fields (those that have no corresponding Field object and
-      // accessed through offset alone) can share offset but have different
-      // immutability properties.
-      // One example is the length property of growable and fixed size list. If
-      // loads of these two properties occur in the same function for the same
-      // receiver then they will get the same expression number. However
-      // immutability of the length of fixed size list does not mean that
-      // growable list also has immutable property. Thus we will make a
-      // conservative assumption for the VM-properties.
-      // TODO(vegorov): disambiguate immutable and non-immutable VM-fields with
-      // the same offset e.g. through recognized kind.
-      return true;
-    }
-
-    return ((place->kind() == Place::kField) ||
-         (place->kind() == Place::kVMField)) &&
-        !CanBeAliased(place->instance());
-  }
-
-  // Returns true if there are direct loads from the given place.
-  bool HasLoadsFromPlace(Definition* defn, const Place* place) {
-    ASSERT((place->kind() == Place::kField) ||
-           (place->kind() == Place::kVMField));
-
-    for (Value* use = defn->input_use_list();
-         use != NULL;
-         use = use->next_use()) {
-      Instruction* instr = use->instruction();
-      if ((instr->IsRedefinition() ||
-           instr->IsAssertAssignable()) &&
-          HasLoadsFromPlace(instr->AsDefinition(), place)) {
-        return true;
-      }
-      bool is_load = false, is_store;
-      Place load_place(instr, &is_load, &is_store);
-
-      if (is_load && load_place.Equals(place)) {
-        return true;
-      }
-    }
-
-    return false;
-  }
-
-  // Check if any use of the definition can create an alias.
-  // Can add more objects into aliasing_worklist_.
-  bool AnyUseCreatesAlias(Definition* defn) {
-    for (Value* use = defn->input_use_list();
-         use != NULL;
-         use = use->next_use()) {
-      Instruction* instr = use->instruction();
-      if (instr->IsPushArgument() ||
-          (instr->IsStoreIndexed()
-           && (use->use_index() == StoreIndexedInstr::kValuePos)) ||
-          instr->IsStoreStaticField() ||
-          instr->IsPhi()) {
-        return true;
-      } else if ((instr->IsAssertAssignable() || instr->IsRedefinition()) &&
-                 AnyUseCreatesAlias(instr->AsDefinition())) {
-        return true;
-      } else if ((instr->IsStoreInstanceField()
-           && (use->use_index() != StoreInstanceFieldInstr::kInstancePos))) {
-        ASSERT(use->use_index() == StoreInstanceFieldInstr::kValuePos);
-        // If we store this value into an object that is not aliased itself
-        // and we never load again then the store does not create an alias.
-        StoreInstanceFieldInstr* store = instr->AsStoreInstanceField();
-        Definition* instance =
-            store->instance()->definition()->OriginalDefinition();
-        if (Place::IsAllocation(instance) &&
-            !instance->Identity().IsAliased()) {
-          bool is_load, is_store;
-          Place store_place(instr, &is_load, &is_store);
-
-          if (!HasLoadsFromPlace(instance, &store_place)) {
-            // No loads found that match this store. If it is yet unknown if
-            // the object is not aliased then optimistically assume this but
-            // add it to the worklist to check its uses transitively.
-            if (instance->Identity().IsUnknown()) {
-              instance->SetIdentity(AliasIdentity::NotAliased());
-              aliasing_worklist_.Add(instance);
-            }
-            continue;
-          }
-        }
-        return true;
-      }
-    }
-    return false;
-  }
-
-  // Mark any value stored into the given object as potentially aliased.
-  void MarkStoredValuesEscaping(Definition* defn) {
-    // Find all stores into this object.
-    for (Value* use = defn->input_use_list();
-         use != NULL;
-         use = use->next_use()) {
-      if (use->instruction()->IsRedefinition() ||
-          use->instruction()->IsAssertAssignable()) {
-        MarkStoredValuesEscaping(use->instruction()->AsDefinition());
-        continue;
-      }
-      if ((use->use_index() == StoreInstanceFieldInstr::kInstancePos) &&
-          use->instruction()->IsStoreInstanceField()) {
-        StoreInstanceFieldInstr* store =
-            use->instruction()->AsStoreInstanceField();
-        Definition* value = store->value()->definition()->OriginalDefinition();
-        if (value->Identity().IsNotAliased()) {
-          value->SetIdentity(AliasIdentity::Aliased());
-          identity_rollback_.Add(value);
-
-          // Add to worklist to propagate the mark transitively.
-          aliasing_worklist_.Add(value);
-        }
-      }
-    }
-  }
-
-  // Determine if the given definition can't be aliased.
-  void ComputeAliasing(Definition* alloc) {
-    ASSERT(Place::IsAllocation(alloc));
-    ASSERT(alloc->Identity().IsUnknown());
-    ASSERT(aliasing_worklist_.is_empty());
-
-    alloc->SetIdentity(AliasIdentity::NotAliased());
-    aliasing_worklist_.Add(alloc);
-
-    while (!aliasing_worklist_.is_empty()) {
-      Definition* defn = aliasing_worklist_.RemoveLast();
-      ASSERT(Place::IsAllocation(defn));
-      // If the definition in the worklist was optimistically marked as
-      // not-aliased check that optimistic assumption still holds: check if
-      // any of its uses can create an alias.
-      if (!defn->Identity().IsAliased() && AnyUseCreatesAlias(defn)) {
-        defn->SetIdentity(AliasIdentity::Aliased());
-        identity_rollback_.Add(defn);
-      }
-
-      // If the allocation site is marked as aliased conservatively mark
-      // any values stored into the object aliased too.
-      if (defn->Identity().IsAliased()) {
-        MarkStoredValuesEscaping(defn);
-      }
-    }
-  }
-
-  Isolate* isolate_;
-
-  DirectChainedHashMap<PointerKeyValueTrait<Place> >* places_map_;
-
-  const ZoneGrowableArray<Place*>& places_;
-
-  const PhiPlaceMoves* phi_moves_;
-
-  // A list of all seen aliases and a map that allows looking up canonical
-  // alias object.
-  GrowableArray<const Place*> aliases_;
-  DirectChainedHashMap<PointerKeyValueTrait<const Place> > aliases_map_;
-
-  // Maps alias id to set of ids of places representing the alias.
-  // Place represents an alias if this alias is least generic alias for
-  // the place.
-  // (see ToAlias for the definition of least generic alias).
-  GrowableArray<BitVector*> representatives_;
-
-  // Maps alias id to set of ids of places aliased.
-  GrowableArray<BitVector*> killed_;
-
-  // Set of ids of places that can be affected by side-effects other than
-  // explicit stores (i.e. through calls).
-  BitVector* aliased_by_effects_;
-
-  // Worklist used during alias analysis.
-  GrowableArray<Definition*> aliasing_worklist_;
-
-  // List of definitions that had their identity set to Aliased. At the end
-  // of load optimization their identity will be rolled back to Unknown to
-  // avoid treating them as Aliased at later stages without checking first
-  // as optimizations can potentially eliminate instructions leading to
-  // aliasing.
-  GrowableArray<Definition*> identity_rollback_;
-};
-
-
-static Definition* GetStoredValue(Instruction* instr) {
-  if (instr->IsStoreIndexed()) {
-    return instr->AsStoreIndexed()->value()->definition();
-  }
-
-  StoreInstanceFieldInstr* store_instance_field = instr->AsStoreInstanceField();
-  if (store_instance_field != NULL) {
-    return store_instance_field->value()->definition();
-  }
-
-  StoreStaticFieldInstr* store_static_field = instr->AsStoreStaticField();
-  if (store_static_field != NULL) {
-    return store_static_field->value()->definition();
-  }
-
-  UNREACHABLE();  // Should only be called for supported store instructions.
-  return NULL;
-}
-
-
-static bool IsPhiDependentPlace(Place* place) {
-  return ((place->kind() == Place::kField) ||
-          (place->kind() == Place::kVMField)) &&
-        (place->instance() != NULL) &&
-        place->instance()->IsPhi();
-}
-
-
-// For each place that depends on a phi ensure that equivalent places
-// corresponding to phi input are numbered and record outgoing phi moves
-// for each block which establish correspondence between phi dependent place
-// and phi input's place that is flowing in.
-static PhiPlaceMoves* ComputePhiMoves(
-    DirectChainedHashMap<PointerKeyValueTrait<Place> >* map,
-    ZoneGrowableArray<Place*>* places) {
-  Isolate* isolate = Isolate::Current();
-  PhiPlaceMoves* phi_moves = new(isolate) PhiPlaceMoves();
-
-  for (intptr_t i = 0; i < places->length(); i++) {
-    Place* place = (*places)[i];
-
-    if (IsPhiDependentPlace(place)) {
-      PhiInstr* phi = place->instance()->AsPhi();
-      BlockEntryInstr* block = phi->GetBlock();
-
-      if (FLAG_trace_optimization) {
-        OS::Print("phi dependent place %s\n", place->ToCString());
-      }
-
-      Place input_place(*place);
-      for (intptr_t j = 0; j < phi->InputCount(); j++) {
-        input_place.set_instance(phi->InputAt(j)->definition());
-
-        Place* result = map->Lookup(&input_place);
-        if (result == NULL) {
-          result = Place::Wrap(isolate, input_place, places->length());
-          map->Insert(result);
-          places->Add(result);
-          if (FLAG_trace_optimization) {
-            OS::Print("  adding place %s as %" Pd "\n",
-                      result->ToCString(),
-                      result->id());
-          }
-        }
-        phi_moves->CreateOutgoingMove(isolate,
-                                      block->PredecessorAt(j),
-                                      result->id(),
-                                      place->id());
-      }
-    }
-  }
-
-  return phi_moves;
-}
-
-
-enum CSEMode {
-  kOptimizeLoads,
-  kOptimizeStores
-};
-
-
-static AliasedSet* NumberPlaces(
-    FlowGraph* graph,
-    DirectChainedHashMap<PointerKeyValueTrait<Place> >* map,
-    CSEMode mode) {
-  // Loads representing different expression ids will be collected and
-  // used to build per offset kill sets.
-  Isolate* isolate = graph->isolate();
-  ZoneGrowableArray<Place*>* places =
-      new(isolate) ZoneGrowableArray<Place*>(10);
-
-  bool has_loads = false;
-  bool has_stores = false;
-  for (BlockIterator it = graph->reverse_postorder_iterator();
-       !it.Done();
-       it.Advance()) {
-    BlockEntryInstr* block = it.Current();
-
-    for (ForwardInstructionIterator instr_it(block);
-         !instr_it.Done();
-         instr_it.Advance()) {
-      Instruction* instr = instr_it.Current();
-      Place place(instr, &has_loads, &has_stores);
-      if (place.kind() == Place::kNone) {
-        continue;
-      }
-
-      Place* result = map->Lookup(&place);
-      if (result == NULL) {
-        result = Place::Wrap(isolate, place, places->length());
-        map->Insert(result);
-        places->Add(result);
-
-        if (FLAG_trace_optimization) {
-          OS::Print("numbering %s as %" Pd "\n",
-                    result->ToCString(),
-                    result->id());
-        }
-      }
-
-      instr->set_place_id(result->id());
-    }
-  }
-
-  if ((mode == kOptimizeLoads) && !has_loads) {
-    return NULL;
-  }
-  if ((mode == kOptimizeStores) && !has_stores) {
-    return NULL;
-  }
-
-  PhiPlaceMoves* phi_moves = ComputePhiMoves(map, places);
-
-  // Build aliasing sets mapping aliases to loads.
-  return new(isolate) AliasedSet(isolate, map, places, phi_moves);
-}
-
-
-class LoadOptimizer : public ValueObject {
- public:
-  LoadOptimizer(FlowGraph* graph, AliasedSet* aliased_set)
-      : graph_(graph),
-        aliased_set_(aliased_set),
-        in_(graph_->preorder().length()),
-        out_(graph_->preorder().length()),
-        gen_(graph_->preorder().length()),
-        kill_(graph_->preorder().length()),
-        exposed_values_(graph_->preorder().length()),
-        out_values_(graph_->preorder().length()),
-        phis_(5),
-        worklist_(5),
-        congruency_worklist_(6),
-        in_worklist_(NULL),
-        forwarded_(false) {
-    const intptr_t num_blocks = graph_->preorder().length();
-    for (intptr_t i = 0; i < num_blocks; i++) {
-      out_.Add(NULL);
-      gen_.Add(new(I) BitVector(I, aliased_set_->max_place_id()));
-      kill_.Add(new(I) BitVector(I, aliased_set_->max_place_id()));
-      in_.Add(new(I) BitVector(I, aliased_set_->max_place_id()));
-
-      exposed_values_.Add(NULL);
-      out_values_.Add(NULL);
-    }
-  }
-
-  ~LoadOptimizer() {
-    aliased_set_->RollbackAliasedIdentites();
-  }
-
-  Isolate* isolate() const { return graph_->isolate(); }
-
-  static bool OptimizeGraph(FlowGraph* graph) {
-    ASSERT(FLAG_load_cse);
-    if (FLAG_trace_load_optimization) {
-      FlowGraphPrinter::PrintGraph("Before LoadOptimizer", graph);
-    }
-
-    DirectChainedHashMap<PointerKeyValueTrait<Place> > map;
-    AliasedSet* aliased_set = NumberPlaces(graph, &map, kOptimizeLoads);
-    if ((aliased_set != NULL) && !aliased_set->IsEmpty()) {
-      // If any loads were forwarded return true from Optimize to run load
-      // forwarding again. This will allow to forward chains of loads.
-      // This is especially important for context variables as they are built
-      // as loads from loaded context.
-      // TODO(vegorov): renumber newly discovered congruences during the
-      // forwarding to forward chains without running whole pass twice.
-      LoadOptimizer load_optimizer(graph, aliased_set);
-      return load_optimizer.Optimize();
-    }
-    return false;
-  }
-
- private:
-  bool Optimize() {
-    ComputeInitialSets();
-    ComputeOutSets();
-    ComputeOutValues();
-    if (graph_->is_licm_allowed()) {
-      MarkLoopInvariantLoads();
-    }
-    ForwardLoads();
-    EmitPhis();
-
-    if (FLAG_trace_load_optimization) {
-      FlowGraphPrinter::PrintGraph("After LoadOptimizer", graph_);
-    }
-
-    return forwarded_;
-  }
-
-  // Compute sets of loads generated and killed by each block.
-  // Additionally compute upwards exposed and generated loads for each block.
-  // Exposed loads are those that can be replaced if a corresponding
-  // reaching load will be found.
-  // Loads that are locally redundant will be replaced as we go through
-  // instructions.
-  void ComputeInitialSets() {
-    for (BlockIterator block_it = graph_->reverse_postorder_iterator();
-         !block_it.Done();
-         block_it.Advance()) {
-      BlockEntryInstr* block = block_it.Current();
-      const intptr_t preorder_number = block->preorder_number();
-
-      BitVector* kill = kill_[preorder_number];
-      BitVector* gen = gen_[preorder_number];
-
-      ZoneGrowableArray<Definition*>* exposed_values = NULL;
-      ZoneGrowableArray<Definition*>* out_values = NULL;
-
-      for (ForwardInstructionIterator instr_it(block);
-           !instr_it.Done();
-           instr_it.Advance()) {
-        Instruction* instr = instr_it.Current();
-
-        bool is_load = false, is_store = false;
-        Place place(instr, &is_load, &is_store);
-
-        BitVector* killed = NULL;
-        if (is_store) {
-          const intptr_t alias_id =
-              aliased_set_->LookupAliasId(place.ToAlias());
-          if (alias_id != AliasedSet::kNoAlias) {
-            killed = aliased_set_->GetKilledSet(alias_id);
-          } else if (!place.IsFinalField()) {
-            // We encountered unknown alias: this means intrablock load
-            // forwarding refined parameter of this store, for example
-            //
-            //     o   <- alloc()
-            //     a.f <- o
-            //     u   <- a.f
-            //     u.x <- null ;; this store alias is *.x
-            //
-            // after intrablock load forwarding
-            //
-            //     o   <- alloc()
-            //     a.f <- o
-            //     o.x <- null ;; this store alias is o.x
-            //
-            // In this case we fallback to using place id recorded in the
-            // instruction that still points to the old place with a more
-            // generic alias.
-            const intptr_t old_alias_id = aliased_set_->LookupAliasId(
-                aliased_set_->places()[instr->place_id()]->ToAlias());
-            killed = aliased_set_->GetKilledSet(old_alias_id);
-          }
-
-          if (killed != NULL) {
-            kill->AddAll(killed);
-            // There is no need to clear out_values when clearing GEN set
-            // because only those values that are in the GEN set
-            // will ever be used.
-            gen->RemoveAll(killed);
-          }
-
-          // Only forward stores to normal arrays, float64, and simd arrays
-          // to loads because other array stores (intXX/uintXX/float32)
-          // may implicitly convert the value stored.
-          StoreIndexedInstr* array_store = instr->AsStoreIndexed();
-          if ((array_store == NULL) ||
-              (array_store->class_id() == kArrayCid) ||
-              (array_store->class_id() == kTypedDataFloat64ArrayCid) ||
-              (array_store->class_id() == kTypedDataFloat32ArrayCid) ||
-              (array_store->class_id() == kTypedDataFloat32x4ArrayCid)) {
-            Place* canonical_place = aliased_set_->LookupCanonical(&place);
-            if (canonical_place != NULL) {
-              // Store has a corresponding numbered place that might have a
-              // load. Try forwarding stored value to it.
-              gen->Add(canonical_place->id());
-              if (out_values == NULL) out_values = CreateBlockOutValues();
-              (*out_values)[canonical_place->id()] = GetStoredValue(instr);
-            }
-          }
-
-          ASSERT(!instr->IsDefinition() ||
-                 !IsLoadEliminationCandidate(instr->AsDefinition()));
-          continue;
-        } else if (is_load) {
-          // Check if this load needs renumbering because of the intrablock
-          // load forwarding.
-          const Place* canonical = aliased_set_->LookupCanonical(&place);
-          if ((canonical != NULL) &&
-            (canonical->id() != instr->AsDefinition()->place_id())) {
-            instr->AsDefinition()->set_place_id(canonical->id());
-          }
-        }
-
-        // If instruction has effects then kill all loads affected.
-        if (!instr->Effects().IsNone()) {
-          kill->AddAll(aliased_set_->aliased_by_effects());
-          // There is no need to clear out_values when removing values from GEN
-          // set because only those values that are in the GEN set
-          // will ever be used.
-          gen->RemoveAll(aliased_set_->aliased_by_effects());
-          continue;
-        }
-
-        Definition* defn = instr->AsDefinition();
-        if (defn == NULL) {
-          continue;
-        }
-
-        // For object allocation forward initial values of the fields to
-        // subsequent loads. For skip final fields.  Final fields are
-        // initialized in constructor that potentially can be not inlined into
-        // the function that we are currently optimizing. However at the same
-        // time we assume that values of the final fields can be forwarded
-        // across side-effects. If we add 'null' as known values for these
-        // fields here we will incorrectly propagate this null across
-        // constructor invocation.
-        AllocateObjectInstr* alloc = instr->AsAllocateObject();
-        if ((alloc != NULL)) {
-          for (Value* use = alloc->input_use_list();
-               use != NULL;
-               use = use->next_use()) {
-            // Look for all immediate loads from this object.
-            if (use->use_index() != 0) {
-              continue;
-            }
-
-            LoadFieldInstr* load = use->instruction()->AsLoadField();
-            if (load != NULL) {
-              // Found a load. Initialize current value of the field to null for
-              // normal fields, or with type arguments.
-
-              // Forward for all fields for non-escaping objects and only
-              // non-final fields and type arguments for escaping ones.
-              if (aliased_set_->CanBeAliased(alloc) &&
-                  (load->field() != NULL) &&
-                  load->field()->is_final()) {
-                continue;
-              }
-
-              Definition* forward_def = graph_->constant_null();
-              if (alloc->ArgumentCount() > 0) {
-                ASSERT(alloc->ArgumentCount() == 1);
-                intptr_t type_args_offset =
-                    alloc->cls().type_arguments_field_offset();
-                if (load->offset_in_bytes() == type_args_offset) {
-                  forward_def = alloc->PushArgumentAt(0)->value()->definition();
-                }
-              }
-              gen->Add(load->place_id());
-              if (out_values == NULL) out_values = CreateBlockOutValues();
-              (*out_values)[load->place_id()] = forward_def;
-            }
-          }
-          continue;
-        }
-
-        if (!IsLoadEliminationCandidate(defn)) {
-          continue;
-        }
-
-        const intptr_t place_id = defn->place_id();
-        if (gen->Contains(place_id)) {
-          // This is a locally redundant load.
-          ASSERT((out_values != NULL) && ((*out_values)[place_id] != NULL));
-
-          Definition* replacement = (*out_values)[place_id];
-          EnsureSSATempIndex(graph_, defn, replacement);
-          if (FLAG_trace_optimization) {
-            OS::Print("Replacing load v%" Pd " with v%" Pd "\n",
-                      defn->ssa_temp_index(),
-                      replacement->ssa_temp_index());
-          }
-
-          defn->ReplaceUsesWith(replacement);
-          instr_it.RemoveCurrentFromGraph();
-          forwarded_ = true;
-          continue;
-        } else if (!kill->Contains(place_id)) {
-          // This is an exposed load: it is the first representative of a
-          // given expression id and it is not killed on the path from
-          // the block entry.
-          if (exposed_values == NULL) {
-            static const intptr_t kMaxExposedValuesInitialSize = 5;
-            exposed_values = new(I) ZoneGrowableArray<Definition*>(
-                Utils::Minimum(kMaxExposedValuesInitialSize,
-                               aliased_set_->max_place_id()));
-          }
-
-          exposed_values->Add(defn);
-        }
-
-        gen->Add(place_id);
-
-        if (out_values == NULL) out_values = CreateBlockOutValues();
-        (*out_values)[place_id] = defn;
-      }
-
-      exposed_values_[preorder_number] = exposed_values;
-      out_values_[preorder_number] = out_values;
-    }
-  }
-
-  static void PerformPhiMoves(PhiPlaceMoves::MovesList phi_moves,
-                              BitVector* out,
-                              BitVector* forwarded_loads) {
-    forwarded_loads->Clear();
-
-    for (intptr_t i = 0; i < phi_moves->length(); i++) {
-      const intptr_t from = (*phi_moves)[i].from();
-      const intptr_t to = (*phi_moves)[i].to();
-      if (from == to) continue;
-
-      if (out->Contains(from)) {
-        forwarded_loads->Add(to);
-      }
-    }
-
-    for (intptr_t i = 0; i < phi_moves->length(); i++) {
-      const intptr_t from = (*phi_moves)[i].from();
-      const intptr_t to = (*phi_moves)[i].to();
-      if (from == to) continue;
-
-      out->Remove(to);
-    }
-
-    out->AddAll(forwarded_loads);
-  }
-
-  // Compute OUT sets by propagating them iteratively until fix point
-  // is reached.
-  void ComputeOutSets() {
-    BitVector* temp = new(I) BitVector(I, aliased_set_->max_place_id());
-    BitVector* forwarded_loads =
-        new(I) BitVector(I, aliased_set_->max_place_id());
-    BitVector* temp_out = new(I) BitVector(I, aliased_set_->max_place_id());
-
-    bool changed = true;
-    while (changed) {
-      changed = false;
-
-      for (BlockIterator block_it = graph_->reverse_postorder_iterator();
-           !block_it.Done();
-           block_it.Advance()) {
-        BlockEntryInstr* block = block_it.Current();
-
-        const intptr_t preorder_number = block->preorder_number();
-
-        BitVector* block_in = in_[preorder_number];
-        BitVector* block_out = out_[preorder_number];
-        BitVector* block_kill = kill_[preorder_number];
-        BitVector* block_gen = gen_[preorder_number];
-
-        // Compute block_in as the intersection of all out(p) where p
-        // is a predecessor of the current block.
-        if (block->IsGraphEntry()) {
-          temp->Clear();
-        } else {
-          temp->SetAll();
-          ASSERT(block->PredecessorCount() > 0);
-          for (intptr_t i = 0; i < block->PredecessorCount(); i++) {
-            BlockEntryInstr* pred = block->PredecessorAt(i);
-            BitVector* pred_out = out_[pred->preorder_number()];
-            if (pred_out == NULL) continue;
-            PhiPlaceMoves::MovesList phi_moves =
-                aliased_set_->phi_moves()->GetOutgoingMoves(pred);
-            if (phi_moves != NULL) {
-              // If there are phi moves, perform intersection with
-              // a copy of pred_out where the phi moves are applied.
-              temp_out->CopyFrom(pred_out);
-              PerformPhiMoves(phi_moves, temp_out, forwarded_loads);
-              pred_out = temp_out;
-            }
-            temp->Intersect(pred_out);
-          }
-        }
-
-        if (!temp->Equals(*block_in) || (block_out == NULL)) {
-          // If IN set has changed propagate the change to OUT set.
-          block_in->CopyFrom(temp);
-
-          temp->RemoveAll(block_kill);
-          temp->AddAll(block_gen);
-
-          if ((block_out == NULL) || !block_out->Equals(*temp)) {
-            if (block_out == NULL) {
-              block_out = out_[preorder_number] =
-                  new(I) BitVector(I, aliased_set_->max_place_id());
-            }
-            block_out->CopyFrom(temp);
-            changed = true;
-          }
-        }
-      }
-    }
-  }
-
-  // Compute out_values mappings by propagating them in reverse postorder once
-  // through the graph. Generate phis on back edges where eager merge is
-  // impossible.
-  // No replacement is done at this point and thus any out_value[place_id] is
-  // changed at most once: from NULL to an actual value.
-  // When merging incoming loads we might need to create a phi.
-  // These phis are not inserted at the graph immediately because some of them
-  // might become redundant after load forwarding is done.
-  void ComputeOutValues() {
-    GrowableArray<PhiInstr*> pending_phis(5);
-    ZoneGrowableArray<Definition*>* temp_forwarded_values = NULL;
-
-    for (BlockIterator block_it = graph_->reverse_postorder_iterator();
-         !block_it.Done();
-         block_it.Advance()) {
-      BlockEntryInstr* block = block_it.Current();
-
-      const bool can_merge_eagerly = CanMergeEagerly(block);
-
-      const intptr_t preorder_number = block->preorder_number();
-
-      ZoneGrowableArray<Definition*>* block_out_values =
-          out_values_[preorder_number];
-
-
-      // If OUT set has changed then we have new values available out of
-      // the block. Compute these values creating phi where necessary.
-      for (BitVector::Iterator it(out_[preorder_number]);
-           !it.Done();
-           it.Advance()) {
-        const intptr_t place_id = it.Current();
-
-        if (block_out_values == NULL) {
-          out_values_[preorder_number] = block_out_values =
-              CreateBlockOutValues();
-        }
-
-        if ((*block_out_values)[place_id] == NULL) {
-          ASSERT(block->PredecessorCount() > 0);
-          Definition* in_value = can_merge_eagerly ?
-              MergeIncomingValues(block, place_id) : NULL;
-          if ((in_value == NULL) &&
-              (in_[preorder_number]->Contains(place_id))) {
-            PhiInstr* phi = new(I) PhiInstr(block->AsJoinEntry(),
-                                            block->PredecessorCount());
-            phi->set_place_id(place_id);
-            pending_phis.Add(phi);
-            in_value = phi;
-          }
-          (*block_out_values)[place_id] = in_value;
-        }
-      }
-
-      // If the block has outgoing phi moves perform them. Use temporary list
-      // of values to ensure that cyclic moves are performed correctly.
-      PhiPlaceMoves::MovesList phi_moves =
-          aliased_set_->phi_moves()->GetOutgoingMoves(block);
-      if ((phi_moves != NULL) && (block_out_values != NULL)) {
-        if (temp_forwarded_values == NULL) {
-          temp_forwarded_values = CreateBlockOutValues();
-        }
-
-        for (intptr_t i = 0; i < phi_moves->length(); i++) {
-          const intptr_t from = (*phi_moves)[i].from();
-          const intptr_t to = (*phi_moves)[i].to();
-          if (from == to) continue;
-
-          (*temp_forwarded_values)[to] = (*block_out_values)[from];
-        }
-
-        for (intptr_t i = 0; i < phi_moves->length(); i++) {
-          const intptr_t from = (*phi_moves)[i].from();
-          const intptr_t to = (*phi_moves)[i].to();
-          if (from == to) continue;
-
-          (*block_out_values)[to] = (*temp_forwarded_values)[to];
-        }
-      }
-
-      if (FLAG_trace_load_optimization) {
-        OS::Print("B%" Pd "\n", block->block_id());
-        OS::Print("  IN: ");
-        aliased_set_->PrintSet(in_[preorder_number]);
-        OS::Print("\n");
-
-        OS::Print("  KILL: ");
-        aliased_set_->PrintSet(kill_[preorder_number]);
-        OS::Print("\n");
-
-        OS::Print("  OUT: ");
-        aliased_set_->PrintSet(out_[preorder_number]);
-        OS::Print("\n");
-      }
-    }
-
-    // All blocks were visited. Fill pending phis with inputs
-    // that flow on back edges.
-    for (intptr_t i = 0; i < pending_phis.length(); i++) {
-      FillPhiInputs(pending_phis[i]);
-    }
-  }
-
-  bool CanMergeEagerly(BlockEntryInstr* block) {
-    for (intptr_t i = 0; i < block->PredecessorCount(); i++) {
-      BlockEntryInstr* pred = block->PredecessorAt(i);
-      if (pred->postorder_number() < block->postorder_number()) {
-        return false;
-      }
-    }
-    return true;
-  }
-
-  void MarkLoopInvariantLoads() {
-    const ZoneGrowableArray<BlockEntryInstr*>& loop_headers =
-        graph_->LoopHeaders();
-
-    ZoneGrowableArray<BitVector*>* invariant_loads =
-        new(I) ZoneGrowableArray<BitVector*>(loop_headers.length());
-
-    for (intptr_t i = 0; i < loop_headers.length(); i++) {
-      BlockEntryInstr* header = loop_headers[i];
-      BlockEntryInstr* pre_header = header->ImmediateDominator();
-      if (pre_header == NULL) {
-        invariant_loads->Add(NULL);
-        continue;
-      }
-
-      BitVector* loop_gen = new(I) BitVector(I, aliased_set_->max_place_id());
-      for (BitVector::Iterator loop_it(header->loop_info());
-           !loop_it.Done();
-           loop_it.Advance()) {
-        const intptr_t preorder_number = loop_it.Current();
-        loop_gen->AddAll(gen_[preorder_number]);
-      }
-
-      for (BitVector::Iterator loop_it(header->loop_info());
-           !loop_it.Done();
-           loop_it.Advance()) {
-        const intptr_t preorder_number = loop_it.Current();
-        loop_gen->RemoveAll(kill_[preorder_number]);
-      }
-
-      if (FLAG_trace_optimization) {
-        for (BitVector::Iterator it(loop_gen); !it.Done(); it.Advance()) {
-          OS::Print("place %s is loop invariant for B%" Pd "\n",
-                    aliased_set_->places()[it.Current()]->ToCString(),
-                    header->block_id());
-        }
-      }
-
-      invariant_loads->Add(loop_gen);
-    }
-
-    graph_->set_loop_invariant_loads(invariant_loads);
-  }
-
-  // Compute incoming value for the given expression id.
-  // Will create a phi if different values are incoming from multiple
-  // predecessors.
-  Definition* MergeIncomingValues(BlockEntryInstr* block, intptr_t place_id) {
-    // First check if the same value is coming in from all predecessors.
-    static Definition* const kDifferentValuesMarker =
-        reinterpret_cast<Definition*>(-1);
-    Definition* incoming = NULL;
-    for (intptr_t i = 0; i < block->PredecessorCount(); i++) {
-      BlockEntryInstr* pred = block->PredecessorAt(i);
-      ZoneGrowableArray<Definition*>* pred_out_values =
-          out_values_[pred->preorder_number()];
-      if ((pred_out_values == NULL) || ((*pred_out_values)[place_id] == NULL)) {
-        return NULL;
-      } else if (incoming == NULL) {
-        incoming = (*pred_out_values)[place_id];
-      } else if (incoming != (*pred_out_values)[place_id]) {
-        incoming = kDifferentValuesMarker;
-      }
-    }
-
-    if (incoming != kDifferentValuesMarker) {
-      ASSERT(incoming != NULL);
-      return incoming;
-    }
-
-    // Incoming values are different. Phi is required to merge.
-    PhiInstr* phi = new(I) PhiInstr(
-        block->AsJoinEntry(), block->PredecessorCount());
-    phi->set_place_id(place_id);
-    FillPhiInputs(phi);
-    return phi;
-  }
-
-  void FillPhiInputs(PhiInstr* phi) {
-    BlockEntryInstr* block = phi->GetBlock();
-    const intptr_t place_id = phi->place_id();
-
-    for (intptr_t i = 0; i < block->PredecessorCount(); i++) {
-      BlockEntryInstr* pred = block->PredecessorAt(i);
-      ZoneGrowableArray<Definition*>* pred_out_values =
-          out_values_[pred->preorder_number()];
-      ASSERT((*pred_out_values)[place_id] != NULL);
-
-      // Sets of outgoing values are not linked into use lists so
-      // they might contain values that were replaced and removed
-      // from the graph by this iteration.
-      // To prevent using them we additionally mark definitions themselves
-      // as replaced and store a pointer to the replacement.
-      Definition* replacement = (*pred_out_values)[place_id]->Replacement();
-      Value* input = new(I) Value(replacement);
-      phi->SetInputAt(i, input);
-      replacement->AddInputUse(input);
-    }
-
-    phi->set_ssa_temp_index(graph_->alloc_ssa_temp_index());
-    phis_.Add(phi);  // Postpone phi insertion until after load forwarding.
-
-    if (FLAG_trace_load_optimization) {
-      OS::Print("created pending phi %s for %s at B%" Pd "\n",
-                phi->ToCString(),
-                aliased_set_->places()[place_id]->ToCString(),
-                block->block_id());
-    }
-  }
-
-  // Iterate over basic blocks and replace exposed loads with incoming
-  // values.
-  void ForwardLoads() {
-    for (BlockIterator block_it = graph_->reverse_postorder_iterator();
-         !block_it.Done();
-         block_it.Advance()) {
-      BlockEntryInstr* block = block_it.Current();
-
-      ZoneGrowableArray<Definition*>* loads =
-          exposed_values_[block->preorder_number()];
-      if (loads == NULL) continue;  // No exposed loads.
-
-      BitVector* in = in_[block->preorder_number()];
-
-      for (intptr_t i = 0; i < loads->length(); i++) {
-        Definition* load = (*loads)[i];
-        if (!in->Contains(load->place_id())) continue;  // No incoming value.
-
-        Definition* replacement = MergeIncomingValues(block, load->place_id());
-        ASSERT(replacement != NULL);
-
-        // Sets of outgoing values are not linked into use lists so
-        // they might contain values that were replace and removed
-        // from the graph by this iteration.
-        // To prevent using them we additionally mark definitions themselves
-        // as replaced and store a pointer to the replacement.
-        replacement = replacement->Replacement();
-
-        if (load != replacement) {
-          EnsureSSATempIndex(graph_, load, replacement);
-
-          if (FLAG_trace_optimization) {
-            OS::Print("Replacing load v%" Pd " with v%" Pd "\n",
-                      load->ssa_temp_index(),
-                      replacement->ssa_temp_index());
-          }
-
-          load->ReplaceUsesWith(replacement);
-          load->RemoveFromGraph();
-          load->SetReplacement(replacement);
-          forwarded_ = true;
-        }
-      }
-    }
-  }
-
-  // Check if the given phi take the same value on all code paths.
-  // Eliminate it as redundant if this is the case.
-  // When analyzing phi operands assumes that only generated during
-  // this load phase can be redundant. They can be distinguished because
-  // they are not marked alive.
-  // TODO(vegorov): move this into a separate phase over all phis.
-  bool EliminateRedundantPhi(PhiInstr* phi) {
-    Definition* value = NULL;  // Possible value of this phi.
-
-    worklist_.Clear();
-    if (in_worklist_ == NULL) {
-      in_worklist_ = new(I) BitVector(I, graph_->current_ssa_temp_index());
-    } else {
-      in_worklist_->Clear();
-    }
-
-    worklist_.Add(phi);
-    in_worklist_->Add(phi->ssa_temp_index());
-
-    for (intptr_t i = 0; i < worklist_.length(); i++) {
-      PhiInstr* phi = worklist_[i];
-
-      for (intptr_t i = 0; i < phi->InputCount(); i++) {
-        Definition* input = phi->InputAt(i)->definition();
-        if (input == phi) continue;
-
-        PhiInstr* phi_input = input->AsPhi();
-        if ((phi_input != NULL) && !phi_input->is_alive()) {
-          if (!in_worklist_->Contains(phi_input->ssa_temp_index())) {
-            worklist_.Add(phi_input);
-            in_worklist_->Add(phi_input->ssa_temp_index());
-          }
-          continue;
-        }
-
-        if (value == NULL) {
-          value = input;
-        } else if (value != input) {
-          return false;  // This phi is not redundant.
-        }
-      }
-    }
-
-    // All phis in the worklist are redundant and have the same computed
-    // value on all code paths.
-    ASSERT(value != NULL);
-    for (intptr_t i = 0; i < worklist_.length(); i++) {
-      worklist_[i]->ReplaceUsesWith(value);
-    }
-
-    return true;
-  }
-
-  // Returns true if definitions are congruent assuming their inputs
-  // are congruent.
-  bool CanBeCongruent(Definition* a, Definition* b) {
-    return (a->tag() == b->tag()) &&
-       ((a->IsPhi() && (a->GetBlock() == b->GetBlock())) ||
-        (a->AllowsCSE() && a->Dependencies().IsNone() &&
-         a->AttributesEqual(b)));
-  }
-
-  // Given two definitions check if they are congruent under assumption that
-  // their inputs will be proven congruent. If they are - add them to the
-  // worklist to check their inputs' congruency.
-  // Returns true if pair was added to the worklist or is already in the
-  // worklist and false if a and b are not congruent.
-  bool AddPairToCongruencyWorklist(Definition* a, Definition* b) {
-    if (!CanBeCongruent(a, b)) {
-      return false;
-    }
-
-    // If a is already in the worklist check if it is being compared to b.
-    // Give up if it is not.
-    if (in_worklist_->Contains(a->ssa_temp_index())) {
-      for (intptr_t i = 0; i < congruency_worklist_.length(); i += 2) {
-        if (a == congruency_worklist_[i]) {
-          return (b == congruency_worklist_[i + 1]);
-        }
-      }
-      UNREACHABLE();
-    } else if (in_worklist_->Contains(b->ssa_temp_index())) {
-      return AddPairToCongruencyWorklist(b, a);
-    }
-
-    congruency_worklist_.Add(a);
-    congruency_worklist_.Add(b);
-    in_worklist_->Add(a->ssa_temp_index());
-    return true;
-  }
-
-  bool AreInputsCongruent(Definition* a, Definition* b) {
-    ASSERT(a->tag() == b->tag());
-    ASSERT(a->InputCount() == b->InputCount());
-    for (intptr_t j = 0; j < a->InputCount(); j++) {
-      Definition* inputA = a->InputAt(j)->definition();
-      Definition* inputB = b->InputAt(j)->definition();
-
-      if (inputA != inputB) {
-        if (!AddPairToCongruencyWorklist(inputA, inputB)) {
-          return false;
-        }
-      }
-    }
-    return true;
-  }
-
-  // Returns true if instruction dom dominates instruction other.
-  static bool Dominates(Instruction* dom, Instruction* other) {
-    BlockEntryInstr* dom_block = dom->GetBlock();
-    BlockEntryInstr* other_block = other->GetBlock();
-
-    if (dom_block == other_block) {
-      for (Instruction* current = dom->next();
-           current != NULL;
-           current = current->next()) {
-        if (current == other) {
-          return true;
-        }
-      }
-      return false;
-    }
-
-    return dom_block->Dominates(other_block);
-  }
-
-  // Replace the given phi with another if they are congruent.
-  // Returns true if succeeds.
-  bool ReplacePhiWith(PhiInstr* phi, PhiInstr* replacement) {
-    ASSERT(phi->InputCount() == replacement->InputCount());
-    ASSERT(phi->block() == replacement->block());
-
-    congruency_worklist_.Clear();
-    if (in_worklist_ == NULL) {
-      in_worklist_ = new(I) BitVector(I, graph_->current_ssa_temp_index());
-    } else {
-      in_worklist_->Clear();
-    }
-
-    // During the comparison worklist contains pairs of definitions to be
-    // compared.
-    if (!AddPairToCongruencyWorklist(phi, replacement)) {
-      return false;
-    }
-
-    // Process the worklist. It might grow during each comparison step.
-    for (intptr_t i = 0; i < congruency_worklist_.length(); i += 2) {
-      if (!AreInputsCongruent(congruency_worklist_[i],
-                              congruency_worklist_[i + 1])) {
-        return false;
-      }
-    }
-
-    // At this point worklist contains pairs of congruent definitions.
-    // Replace the one member of the pair with another maintaining proper
-    // domination relation between definitions and uses.
-    for (intptr_t i = 0; i < congruency_worklist_.length(); i += 2) {
-      Definition* a = congruency_worklist_[i];
-      Definition* b = congruency_worklist_[i + 1];
-
-      // If these definitions are not phis then we need to pick up one
-      // that dominates another as the replacement: if a dominates b swap them.
-      // Note: both a and b are used as a phi input at the same block B which
-      // means a dominates B and b dominates B, which guarantees that either
-      // a dominates b or b dominates a.
-      if (!a->IsPhi()) {
-        if (Dominates(a, b)) {
-          Definition* t = a;
-          a = b;
-          b = t;
-        }
-        ASSERT(Dominates(b, a));
-      }
-
-      if (FLAG_trace_load_optimization) {
-        OS::Print("Replacing %s with congruent %s\n",
-                  a->ToCString(),
-                  b->ToCString());
-      }
-
-      a->ReplaceUsesWith(b);
-      if (a->IsPhi()) {
-        // We might be replacing a phi introduced by the load forwarding
-        // that is not inserted in the graph yet.
-        ASSERT(b->IsPhi());
-        PhiInstr* phi_a = a->AsPhi();
-        if (phi_a->is_alive()) {
-          phi_a->mark_dead();
-          phi_a->block()->RemovePhi(phi_a);
-          phi_a->UnuseAllInputs();
-        }
-      } else {
-        a->RemoveFromGraph();
-      }
-    }
-
-    return true;
-  }
-
-  // Insert the given phi into the graph. Attempt to find an equal one in the
-  // target block first.
-  // Returns true if the phi was inserted and false if it was replaced.
-  bool EmitPhi(PhiInstr* phi) {
-    for (PhiIterator it(phi->block()); !it.Done(); it.Advance()) {
-      if (ReplacePhiWith(phi, it.Current())) {
-        return false;
-      }
-    }
-
-    phi->mark_alive();
-    phi->block()->InsertPhi(phi);
-    return true;
-  }
-
-  // Phis have not yet been inserted into the graph but they have uses of
-  // their inputs.  Insert the non-redundant ones and clear the input uses
-  // of the redundant ones.
-  void EmitPhis() {
-    // First eliminate all redundant phis.
-    for (intptr_t i = 0; i < phis_.length(); i++) {
-      PhiInstr* phi = phis_[i];
-      if (!phi->HasUses() || EliminateRedundantPhi(phi)) {
-        phi->UnuseAllInputs();
-        phis_[i] = NULL;
-      }
-    }
-
-    // Now emit phis or replace them with equal phis already present in the
-    // graph.
-    for (intptr_t i = 0; i < phis_.length(); i++) {
-      PhiInstr* phi = phis_[i];
-      if ((phi != NULL) && (!phi->HasUses() || !EmitPhi(phi))) {
-        phi->UnuseAllInputs();
-      }
-    }
-  }
-
-  ZoneGrowableArray<Definition*>* CreateBlockOutValues() {
-    ZoneGrowableArray<Definition*>* out =
-        new(I) ZoneGrowableArray<Definition*>(aliased_set_->max_place_id());
-    for (intptr_t i = 0; i < aliased_set_->max_place_id(); i++) {
-      out->Add(NULL);
-    }
-    return out;
-  }
-
-  FlowGraph* graph_;
-  DirectChainedHashMap<PointerKeyValueTrait<Place> >* map_;
-
-  // Mapping between field offsets in words and expression ids of loads from
-  // that offset.
-  AliasedSet* aliased_set_;
-
-  // Per block sets of expression ids for loads that are: incoming (available
-  // on the entry), outgoing (available on the exit), generated and killed.
-  GrowableArray<BitVector*> in_;
-  GrowableArray<BitVector*> out_;
-  GrowableArray<BitVector*> gen_;
-  GrowableArray<BitVector*> kill_;
-
-  // Per block list of upwards exposed loads.
-  GrowableArray<ZoneGrowableArray<Definition*>*> exposed_values_;
-
-  // Per block mappings between expression ids and outgoing definitions that
-  // represent those ids.
-  GrowableArray<ZoneGrowableArray<Definition*>*> out_values_;
-
-  // List of phis generated during ComputeOutValues and ForwardLoads.
-  // Some of these phis might be redundant and thus a separate pass is
-  // needed to emit only non-redundant ones.
-  GrowableArray<PhiInstr*> phis_;
-
-  // Auxiliary worklist used by redundant phi elimination.
-  GrowableArray<PhiInstr*> worklist_;
-  GrowableArray<Definition*> congruency_worklist_;
-  BitVector* in_worklist_;
-
-
-  // True if any load was eliminated.
-  bool forwarded_;
-
-  DISALLOW_COPY_AND_ASSIGN(LoadOptimizer);
-};
-
-
-class StoreOptimizer : public LivenessAnalysis {
- public:
-  StoreOptimizer(FlowGraph* graph,
-                 AliasedSet* aliased_set,
-                 DirectChainedHashMap<PointerKeyValueTrait<Place> >* map)
-      : LivenessAnalysis(aliased_set->max_place_id(), graph->postorder()),
-        graph_(graph),
-        map_(map),
-        aliased_set_(aliased_set),
-        exposed_stores_(graph_->postorder().length()) {
-    const intptr_t num_blocks = graph_->postorder().length();
-    for (intptr_t i = 0; i < num_blocks; i++) {
-      exposed_stores_.Add(NULL);
-    }
-  }
-
-  static void OptimizeGraph(FlowGraph* graph) {
-    ASSERT(FLAG_load_cse);
-    if (FLAG_trace_load_optimization) {
-      FlowGraphPrinter::PrintGraph("Before StoreOptimizer", graph);
-    }
-
-    DirectChainedHashMap<PointerKeyValueTrait<Place> > map;
-    AliasedSet* aliased_set = NumberPlaces(graph, &map, kOptimizeStores);
-    if ((aliased_set != NULL) && !aliased_set->IsEmpty()) {
-      StoreOptimizer store_optimizer(graph, aliased_set, &map);
-      store_optimizer.Optimize();
-    }
-  }
-
- private:
-  void Optimize() {
-    Analyze();
-    if (FLAG_trace_load_optimization) {
-      Dump();
-    }
-    EliminateDeadStores();
-    if (FLAG_trace_load_optimization) {
-      FlowGraphPrinter::PrintGraph("After StoreOptimizer", graph_);
-    }
-  }
-
-  bool CanEliminateStore(Instruction* instr) {
-    switch (instr->tag()) {
-      case Instruction::kStoreInstanceField:
-        if (instr->AsStoreInstanceField()->is_initialization()) {
-          // Can't eliminate stores that initialized unboxed fields.
-          return false;
-        }
-      case Instruction::kStoreIndexed:
-      case Instruction::kStoreStaticField:
-        return true;
-      default:
-        UNREACHABLE();
-        return false;
-    }
-  }
-
-  virtual void ComputeInitialSets() {
-    Isolate* isolate = graph_->isolate();
-    BitVector* all_places = new(isolate) BitVector(isolate,
-        aliased_set_->max_place_id());
-    all_places->SetAll();
-    for (BlockIterator block_it = graph_->postorder_iterator();
-         !block_it.Done();
-         block_it.Advance()) {
-      BlockEntryInstr* block = block_it.Current();
-      const intptr_t postorder_number = block->postorder_number();
-
-      BitVector* kill = kill_[postorder_number];
-      BitVector* live_in = live_in_[postorder_number];
-      BitVector* live_out = live_out_[postorder_number];
-
-      ZoneGrowableArray<Instruction*>* exposed_stores = NULL;
-
-      // Iterate backwards starting at the last instruction.
-      for (BackwardInstructionIterator instr_it(block);
-           !instr_it.Done();
-           instr_it.Advance()) {
-        Instruction* instr = instr_it.Current();
-
-        bool is_load = false;
-        bool is_store = false;
-        Place place(instr, &is_load, &is_store);
-        if (place.IsFinalField()) {
-          // Loads/stores of final fields do not participate.
-          continue;
-        }
-
-        // Handle stores.
-        if (is_store) {
-          if (kill->Contains(instr->place_id())) {
-            if (!live_in->Contains(instr->place_id()) &&
-                CanEliminateStore(instr)) {
-              if (FLAG_trace_optimization) {
-                OS::Print(
-                    "Removing dead store to place %" Pd " in block B%" Pd "\n",
-                    instr->place_id(), block->block_id());
-              }
-              instr_it.RemoveCurrentFromGraph();
-            }
-          } else if (!live_in->Contains(instr->place_id())) {
-            // Mark this store as down-ward exposed: They are the only
-            // candidates for the global store elimination.
-            if (exposed_stores == NULL) {
-              const intptr_t kMaxExposedStoresInitialSize = 5;
-              exposed_stores = new(isolate) ZoneGrowableArray<Instruction*>(
-                  Utils::Minimum(kMaxExposedStoresInitialSize,
-                                 aliased_set_->max_place_id()));
-            }
-            exposed_stores->Add(instr);
-          }
-          // Interfering stores kill only loads from the same place.
-          kill->Add(instr->place_id());
-          live_in->Remove(instr->place_id());
-          continue;
-        }
-
-        // Handle side effects, deoptimization and function return.
-        if (!instr->Effects().IsNone() ||
-            instr->CanDeoptimize() ||
-            instr->IsThrow() ||
-            instr->IsReThrow() ||
-            instr->IsReturn()) {
-          // Instructions that return from the function, instructions with side
-          // effects and instructions that can deoptimize are considered as
-          // loads from all places.
-          live_in->CopyFrom(all_places);
-          if (instr->IsThrow() || instr->IsReThrow() || instr->IsReturn()) {
-            // Initialize live-out for exit blocks since it won't be computed
-            // otherwise during the fixed point iteration.
-            live_out->CopyFrom(all_places);
-          }
-          continue;
-        }
-
-        // Handle loads.
-        Definition* defn = instr->AsDefinition();
-        if ((defn != NULL) && IsLoadEliminationCandidate(defn)) {
-          const intptr_t alias = aliased_set_->LookupAliasId(place.ToAlias());
-          live_in->AddAll(aliased_set_->GetKilledSet(alias));
-          continue;
-        }
-      }
-      exposed_stores_[postorder_number] = exposed_stores;
-    }
-    if (FLAG_trace_load_optimization) {
-      Dump();
-      OS::Print("---\n");
-    }
-  }
-
-  void EliminateDeadStores() {
-    // Iteration order does not matter here.
-    for (BlockIterator block_it = graph_->postorder_iterator();
-         !block_it.Done();
-         block_it.Advance()) {
-      BlockEntryInstr* block = block_it.Current();
-      const intptr_t postorder_number = block->postorder_number();
-
-      BitVector* live_out = live_out_[postorder_number];
-
-      ZoneGrowableArray<Instruction*>* exposed_stores =
-        exposed_stores_[postorder_number];
-      if (exposed_stores == NULL) continue;  // No exposed stores.
-
-      // Iterate over candidate stores.
-      for (intptr_t i = 0; i < exposed_stores->length(); ++i) {
-        Instruction* instr = (*exposed_stores)[i];
-        bool is_load = false;
-        bool is_store = false;
-        Place place(instr, &is_load, &is_store);
-        ASSERT(!is_load && is_store);
-        if (place.IsFinalField()) {
-          // Final field do not participate in dead store elimination.
-          continue;
-        }
-        // Eliminate a downward exposed store if the corresponding place is not
-        // in live-out.
-        if (!live_out->Contains(instr->place_id()) &&
-            CanEliminateStore(instr)) {
-          if (FLAG_trace_optimization) {
-            OS::Print("Removing dead store to place %" Pd " block B%" Pd "\n",
-                      instr->place_id(), block->block_id());
-          }
-          instr->RemoveFromGraph(/* ignored */ false);
-        }
-      }
-    }
-  }
-
-  FlowGraph* graph_;
-  DirectChainedHashMap<PointerKeyValueTrait<Place> >* map_;
-
-  // Mapping between field offsets in words and expression ids of loads from
-  // that offset.
-  AliasedSet* aliased_set_;
-
-  // Per block list of downward exposed stores.
-  GrowableArray<ZoneGrowableArray<Instruction*>*> exposed_stores_;
-
-  DISALLOW_COPY_AND_ASSIGN(StoreOptimizer);
-};
-
-
-void DeadStoreElimination::Optimize(FlowGraph* graph) {
-  if (FLAG_dead_store_elimination) {
-    StoreOptimizer::OptimizeGraph(graph);
-  }
-}
-
-
-// Returns true iff this definition is used in a non-phi instruction.
-static bool HasRealUse(Definition* def) {
-  // Environment uses are real (non-phi) uses.
-  if (def->env_use_list() != NULL) return true;
-
-  for (Value::Iterator it(def->input_use_list());
-       !it.Done();
-       it.Advance()) {
-    if (!it.Current()->instruction()->IsPhi()) return true;
-  }
-  return false;
-}
-
-
-void DeadCodeElimination::EliminateDeadPhis(FlowGraph* flow_graph) {
-  GrowableArray<PhiInstr*> live_phis;
-  for (BlockIterator b = flow_graph->postorder_iterator();
-       !b.Done();
-       b.Advance()) {
-    JoinEntryInstr* join = b.Current()->AsJoinEntry();
-    if (join != NULL) {
-      for (PhiIterator it(join); !it.Done(); it.Advance()) {
-        PhiInstr* phi = it.Current();
-        // Phis that have uses and phis inside try blocks are
-        // marked as live.
-        if (HasRealUse(phi) || join->InsideTryBlock()) {
-          live_phis.Add(phi);
-          phi->mark_alive();
-        } else {
-          phi->mark_dead();
-        }
-      }
-    }
-  }
-
-  while (!live_phis.is_empty()) {
-    PhiInstr* phi = live_phis.RemoveLast();
-    for (intptr_t i = 0; i < phi->InputCount(); i++) {
-      Value* val = phi->InputAt(i);
-      PhiInstr* used_phi = val->definition()->AsPhi();
-      if ((used_phi != NULL) && !used_phi->is_alive()) {
-        used_phi->mark_alive();
-        live_phis.Add(used_phi);
-      }
-    }
-  }
-
-  for (BlockIterator it(flow_graph->postorder_iterator());
-       !it.Done();
-       it.Advance()) {
-    JoinEntryInstr* join = it.Current()->AsJoinEntry();
-    if (join != NULL) {
-      if (join->phis_ == NULL) continue;
-
-      // Eliminate dead phis and compact the phis_ array of the block.
-      intptr_t to_index = 0;
-      for (intptr_t i = 0; i < join->phis_->length(); ++i) {
-        PhiInstr* phi = (*join->phis_)[i];
-        if (phi != NULL) {
-          if (!phi->is_alive()) {
-            phi->ReplaceUsesWith(flow_graph->constant_null());
-            phi->UnuseAllInputs();
-            (*join->phis_)[i] = NULL;
-            if (FLAG_trace_optimization) {
-              OS::Print("Removing dead phi v%" Pd "\n", phi->ssa_temp_index());
-            }
-          } else if (phi->IsRedundant()) {
-            phi->ReplaceUsesWith(phi->InputAt(0)->definition());
-            phi->UnuseAllInputs();
-            (*join->phis_)[i] = NULL;
-            if (FLAG_trace_optimization) {
-              OS::Print("Removing redundant phi v%" Pd "\n",
-                         phi->ssa_temp_index());
-            }
-          } else {
-            (*join->phis_)[to_index++] = phi;
-          }
-        }
-      }
-      if (to_index == 0) {
-        join->phis_ = NULL;
-      } else {
-        join->phis_->TruncateTo(to_index);
-      }
-    }
-  }
-}
-
-
-class CSEInstructionMap : public ValueObject {
- public:
-  // Right now CSE and LICM track a single effect: possible externalization of
-  // strings.
-  // Other effects like modifications of fields are tracked in a separate load
-  // forwarding pass via Alias structure.
-  COMPILE_ASSERT(EffectSet::kLastEffect == 1);
-
-  CSEInstructionMap() : independent_(), dependent_() { }
-  explicit CSEInstructionMap(const CSEInstructionMap& other)
-      : ValueObject(),
-        independent_(other.independent_),
-        dependent_(other.dependent_) {
-  }
-
-  void RemoveAffected(EffectSet effects) {
-    if (!effects.IsNone()) {
-      dependent_.Clear();
-    }
-  }
-
-  Instruction* Lookup(Instruction* other) const {
-    return GetMapFor(other)->Lookup(other);
-  }
-
-  void Insert(Instruction* instr) {
-    return GetMapFor(instr)->Insert(instr);
-  }
-
- private:
-  typedef DirectChainedHashMap<PointerKeyValueTrait<Instruction> >  Map;
-
-  Map* GetMapFor(Instruction* instr) {
-    return instr->Dependencies().IsNone() ? &independent_ : &dependent_;
-  }
-
-  const Map* GetMapFor(Instruction* instr) const {
-    return instr->Dependencies().IsNone() ? &independent_ : &dependent_;
-  }
-
-  // All computations that are not affected by any side-effect.
-  // Majority of computations are not affected by anything and will be in
-  // this map.
-  Map independent_;
-
-  // All computations that are affected by side effect.
-  Map dependent_;
-};
-
-
-bool DominatorBasedCSE::Optimize(FlowGraph* graph) {
-  bool changed = false;
-  if (FLAG_load_cse) {
-    changed = LoadOptimizer::OptimizeGraph(graph) || changed;
-  }
-
-  CSEInstructionMap map;
-  changed = OptimizeRecursive(graph, graph->graph_entry(), &map) || changed;
-
-  return changed;
-}
-
-
-bool DominatorBasedCSE::OptimizeRecursive(
-    FlowGraph* graph,
-    BlockEntryInstr* block,
-    CSEInstructionMap* map) {
-  bool changed = false;
-  for (ForwardInstructionIterator it(block); !it.Done(); it.Advance()) {
-    Instruction* current = it.Current();
-    if (current->AllowsCSE()) {
-      Instruction* replacement = map->Lookup(current);
-      if ((replacement != NULL) &&
-          graph->block_effects()->IsAvailableAt(replacement, block)) {
-        // Replace current with lookup result.
-        ReplaceCurrentInstruction(&it, current, replacement, graph);
-        changed = true;
-        continue;
-      }
-
-      // For simplicity we assume that instruction either does not depend on
-      // anything or does not affect anything. If this is not the case then
-      // we should first remove affected instructions from the map and
-      // then add instruction to the map so that it does not kill itself.
-      ASSERT(current->Effects().IsNone() || current->Dependencies().IsNone());
-      map->Insert(current);
-    }
-
-    map->RemoveAffected(current->Effects());
-  }
-
-  // Process children in the dominator tree recursively.
-  intptr_t num_children = block->dominated_blocks().length();
-  for (intptr_t i = 0; i < num_children; ++i) {
-    BlockEntryInstr* child = block->dominated_blocks()[i];
-    if (i  < num_children - 1) {
-      // Copy map.
-      CSEInstructionMap child_map(*map);
-      changed = OptimizeRecursive(graph, child, &child_map) || changed;
-    } else {
-      // Reuse map for the last child.
-      changed = OptimizeRecursive(graph, child, map) || changed;
-    }
-  }
-  return changed;
-}
-
-
 ConstantPropagator::ConstantPropagator(
     FlowGraph* graph,
     const GrowableArray<BlockEntryInstr*>& ignored)
@@ -8202,7 +725,7 @@
     if ((checked_type.IsFloat32x4Type() && (rep == kUnboxedFloat32x4)) ||
         (checked_type.IsInt32x4Type() && (rep == kUnboxedInt32x4)) ||
         (checked_type.IsDoubleType() && (rep == kUnboxedDouble) &&
-         CanUnboxDouble()) ||
+         FlowGraphCompiler::SupportsUnboxedDoubles()) ||
         (checked_type.IsIntType() && (rep == kUnboxedMint))) {
       // Ensure that compile time type matches representation.
       ASSERT(((rep == kUnboxedFloat32x4) && (value_cid == kFloat32x4Cid)) ||
@@ -9112,976 +1635,4 @@
   }
 }
 
-
-// Returns true if the given phi has a single input use and
-// is used in the environments either at the corresponding block entry or
-// at the same instruction where input use is.
-static bool PhiHasSingleUse(PhiInstr* phi, Value* use) {
-  if ((use->next_use() != NULL) || (phi->input_use_list() != use)) {
-    return false;
-  }
-
-  BlockEntryInstr* block = phi->block();
-  for (Value* env_use = phi->env_use_list();
-       env_use != NULL;
-       env_use = env_use->next_use()) {
-    if ((env_use->instruction() != block) &&
-        (env_use->instruction() != use->instruction())) {
-      return false;
-    }
-  }
-
-  return true;
-}
-
-
-bool BranchSimplifier::Match(JoinEntryInstr* block) {
-  // Match the pattern of a branch on a comparison whose left operand is a
-  // phi from the same block, and whose right operand is a constant.
-  //
-  //   Branch(Comparison(kind, Phi, Constant))
-  //
-  // These are the branches produced by inlining in a test context.  Also,
-  // the phi has no other uses so they can simply be eliminated.  The block
-  // has no other phis and no instructions intervening between the phi and
-  // branch so the block can simply be eliminated.
-  BranchInstr* branch = block->last_instruction()->AsBranch();
-  ASSERT(branch != NULL);
-  ComparisonInstr* comparison = branch->comparison();
-  Value* left = comparison->left();
-  PhiInstr* phi = left->definition()->AsPhi();
-  Value* right = comparison->right();
-  ConstantInstr* constant =
-      (right == NULL) ? NULL : right->definition()->AsConstant();
-  return (phi != NULL) &&
-      (constant != NULL) &&
-      (phi->GetBlock() == block) &&
-      PhiHasSingleUse(phi, left) &&
-      (block->next() == branch) &&
-      (block->phis()->length() == 1);
-}
-
-
-JoinEntryInstr* BranchSimplifier::ToJoinEntry(Isolate* isolate,
-                                              TargetEntryInstr* target) {
-  // Convert a target block into a join block.  Branches will be duplicated
-  // so the former true and false targets become joins of the control flows
-  // from all the duplicated branches.
-  JoinEntryInstr* join =
-      new(isolate) JoinEntryInstr(target->block_id(), target->try_index());
-  join->InheritDeoptTarget(isolate, target);
-  join->LinkTo(target->next());
-  join->set_last_instruction(target->last_instruction());
-  target->UnuseAllInputs();
-  return join;
-}
-
-
-BranchInstr* BranchSimplifier::CloneBranch(Isolate* isolate,
-                                           BranchInstr* branch,
-                                           Value* new_left,
-                                           Value* new_right) {
-  ComparisonInstr* comparison = branch->comparison();
-  ComparisonInstr* new_comparison =
-      comparison->CopyWithNewOperands(new_left, new_right);
-  BranchInstr* new_branch = new(isolate) BranchInstr(new_comparison);
-  new_branch->set_is_checked(branch->is_checked());
-  return new_branch;
-}
-
-
-void BranchSimplifier::Simplify(FlowGraph* flow_graph) {
-  // Optimize some branches that test the value of a phi.  When it is safe
-  // to do so, push the branch to each of the predecessor blocks.  This is
-  // an optimization when (a) it can avoid materializing a boolean object at
-  // the phi only to test its value, and (b) it can expose opportunities for
-  // constant propagation and unreachable code elimination.  This
-  // optimization is intended to run after inlining which creates
-  // opportunities for optimization (a) and before constant folding which
-  // can perform optimization (b).
-
-  // Begin with a worklist of join blocks ending in branches.  They are
-  // candidates for the pattern below.
-  Isolate* isolate = flow_graph->isolate();
-  const GrowableArray<BlockEntryInstr*>& postorder = flow_graph->postorder();
-  GrowableArray<BlockEntryInstr*> worklist(postorder.length());
-  for (BlockIterator it(postorder); !it.Done(); it.Advance()) {
-    BlockEntryInstr* block = it.Current();
-    if (block->IsJoinEntry() && block->last_instruction()->IsBranch()) {
-      worklist.Add(block);
-    }
-  }
-
-  // Rewrite until no more instance of the pattern exists.
-  bool changed = false;
-  while (!worklist.is_empty()) {
-    // All blocks in the worklist are join blocks (ending with a branch).
-    JoinEntryInstr* block = worklist.RemoveLast()->AsJoinEntry();
-    ASSERT(block != NULL);
-
-    if (Match(block)) {
-      changed = true;
-
-      // The branch will be copied and pushed to all the join's
-      // predecessors.  Convert the true and false target blocks into join
-      // blocks to join the control flows from all of the true
-      // (respectively, false) targets of the copied branches.
-      //
-      // The converted join block will have no phis, so it cannot be another
-      // instance of the pattern.  There is thus no need to add it to the
-      // worklist.
-      BranchInstr* branch = block->last_instruction()->AsBranch();
-      ASSERT(branch != NULL);
-      JoinEntryInstr* join_true =
-          ToJoinEntry(isolate, branch->true_successor());
-      JoinEntryInstr* join_false =
-          ToJoinEntry(isolate, branch->false_successor());
-
-      ComparisonInstr* comparison = branch->comparison();
-      PhiInstr* phi = comparison->left()->definition()->AsPhi();
-      ConstantInstr* constant = comparison->right()->definition()->AsConstant();
-      ASSERT(constant != NULL);
-      // Copy the constant and branch and push it to all the predecessors.
-      for (intptr_t i = 0, count = block->PredecessorCount(); i < count; ++i) {
-        GotoInstr* old_goto =
-            block->PredecessorAt(i)->last_instruction()->AsGoto();
-        ASSERT(old_goto != NULL);
-
-        // Replace the goto in each predecessor with a rewritten branch,
-        // rewritten to use the corresponding phi input instead of the phi.
-        Value* new_left = phi->InputAt(i)->Copy(isolate);
-        Value* new_right = new(isolate) Value(constant);
-        BranchInstr* new_branch =
-            CloneBranch(isolate, branch, new_left, new_right);
-        if (branch->env() == NULL) {
-          new_branch->InheritDeoptTarget(isolate, old_goto);
-        } else {
-          // Take the environment from the branch if it has one.
-          new_branch->InheritDeoptTarget(isolate, branch);
-          // InheritDeoptTarget gave the new branch's comparison the same
-          // deopt id that it gave the new branch.  The id should be the
-          // deopt id of the original comparison.
-          new_branch->comparison()->SetDeoptId(*comparison);
-          // The phi can be used in the branch's environment.  Rename such
-          // uses.
-          for (Environment::DeepIterator it(new_branch->env());
-               !it.Done();
-               it.Advance()) {
-            Value* use = it.CurrentValue();
-            if (use->definition() == phi) {
-              Definition* replacement = phi->InputAt(i)->definition();
-              use->RemoveFromUseList();
-              use->set_definition(replacement);
-              replacement->AddEnvUse(use);
-            }
-          }
-        }
-
-        new_branch->InsertBefore(old_goto);
-        new_branch->set_next(NULL);  // Detaching the goto from the graph.
-        old_goto->UnuseAllInputs();
-
-        // Update the predecessor block.  We may have created another
-        // instance of the pattern so add it to the worklist if necessary.
-        BlockEntryInstr* branch_block = new_branch->GetBlock();
-        branch_block->set_last_instruction(new_branch);
-        if (branch_block->IsJoinEntry()) worklist.Add(branch_block);
-
-        // Connect the branch to the true and false joins, via empty target
-        // blocks.
-        TargetEntryInstr* true_target =
-            new(isolate) TargetEntryInstr(flow_graph->max_block_id() + 1,
-                                          block->try_index());
-        true_target->InheritDeoptTarget(isolate, join_true);
-        TargetEntryInstr* false_target =
-            new(isolate) TargetEntryInstr(flow_graph->max_block_id() + 2,
-                                          block->try_index());
-        false_target->InheritDeoptTarget(isolate, join_false);
-        flow_graph->set_max_block_id(flow_graph->max_block_id() + 2);
-        *new_branch->true_successor_address() = true_target;
-        *new_branch->false_successor_address() = false_target;
-        GotoInstr* goto_true = new(isolate) GotoInstr(join_true);
-        goto_true->InheritDeoptTarget(isolate, join_true);
-        true_target->LinkTo(goto_true);
-        true_target->set_last_instruction(goto_true);
-        GotoInstr* goto_false = new(isolate) GotoInstr(join_false);
-        goto_false->InheritDeoptTarget(isolate, join_false);
-        false_target->LinkTo(goto_false);
-        false_target->set_last_instruction(goto_false);
-      }
-      // When all predecessors have been rewritten, the original block is
-      // unreachable from the graph.
-      phi->UnuseAllInputs();
-      branch->UnuseAllInputs();
-      block->UnuseAllInputs();
-      ASSERT(!phi->HasUses());
-    }
-  }
-
-  if (changed) {
-    // We may have changed the block order and the dominator tree.
-    flow_graph->DiscoverBlocks();
-    GrowableArray<BitVector*> dominance_frontier;
-    flow_graph->ComputeDominators(&dominance_frontier);
-  }
-}
-
-
-static bool IsTrivialBlock(BlockEntryInstr* block, Definition* defn) {
-  return (block->IsTargetEntry() && (block->PredecessorCount() == 1)) &&
-    ((block->next() == block->last_instruction()) ||
-     ((block->next() == defn) && (defn->next() == block->last_instruction())));
-}
-
-
-static void EliminateTrivialBlock(BlockEntryInstr* block,
-                                  Definition* instr,
-                                  IfThenElseInstr* before) {
-  block->UnuseAllInputs();
-  block->last_instruction()->UnuseAllInputs();
-
-  if ((block->next() == instr) &&
-      (instr->next() == block->last_instruction())) {
-    before->previous()->LinkTo(instr);
-    instr->LinkTo(before);
-  }
-}
-
-
-void IfConverter::Simplify(FlowGraph* flow_graph) {
-  Isolate* isolate = flow_graph->isolate();
-  bool changed = false;
-
-  const GrowableArray<BlockEntryInstr*>& postorder = flow_graph->postorder();
-  for (BlockIterator it(postorder); !it.Done(); it.Advance()) {
-    BlockEntryInstr* block = it.Current();
-    JoinEntryInstr* join = block->AsJoinEntry();
-
-    // Detect diamond control flow pattern which materializes a value depending
-    // on the result of the comparison:
-    //
-    // B_pred:
-    //   ...
-    //   Branch if COMP goto (B_pred1, B_pred2)
-    // B_pred1: -- trivial block that contains at most one definition
-    //   v1 = Constant(...)
-    //   goto B_block
-    // B_pred2: -- trivial block that contains at most one definition
-    //   v2 = Constant(...)
-    //   goto B_block
-    // B_block:
-    //   v3 = phi(v1, v2) -- single phi
-    //
-    // and replace it with
-    //
-    // Ba:
-    //   v3 = IfThenElse(COMP ? v1 : v2)
-    //
-    if ((join != NULL) &&
-        (join->phis() != NULL) &&
-        (join->phis()->length() == 1) &&
-        (block->PredecessorCount() == 2)) {
-      BlockEntryInstr* pred1 = block->PredecessorAt(0);
-      BlockEntryInstr* pred2 = block->PredecessorAt(1);
-
-      PhiInstr* phi = (*join->phis())[0];
-      Value* v1 = phi->InputAt(0);
-      Value* v2 = phi->InputAt(1);
-
-      if (IsTrivialBlock(pred1, v1->definition()) &&
-          IsTrivialBlock(pred2, v2->definition()) &&
-          (pred1->PredecessorAt(0) == pred2->PredecessorAt(0))) {
-        BlockEntryInstr* pred = pred1->PredecessorAt(0);
-        BranchInstr* branch = pred->last_instruction()->AsBranch();
-        ComparisonInstr* comparison = branch->comparison();
-
-        // Check if the platform supports efficient branchless IfThenElseInstr
-        // for the given combination of comparison and values flowing from
-        // false and true paths.
-        if (IfThenElseInstr::Supports(comparison, v1, v2)) {
-          Value* if_true = (pred1 == branch->true_successor()) ? v1 : v2;
-          Value* if_false = (pred2 == branch->true_successor()) ? v1 : v2;
-
-          ComparisonInstr* new_comparison =
-              comparison->CopyWithNewOperands(
-                  comparison->left()->Copy(isolate),
-                  comparison->right()->Copy(isolate));
-          IfThenElseInstr* if_then_else = new(isolate) IfThenElseInstr(
-              new_comparison,
-              if_true->Copy(isolate),
-              if_false->Copy(isolate));
-          flow_graph->InsertBefore(branch,
-                                   if_then_else,
-                                   NULL,
-                                   FlowGraph::kValue);
-
-          phi->ReplaceUsesWith(if_then_else);
-
-          // Connect IfThenElseInstr to the first instruction in the merge block
-          // effectively eliminating diamond control flow.
-          // Current block as well as pred1 and pred2 blocks are no longer in
-          // the graph at this point.
-          if_then_else->LinkTo(join->next());
-          pred->set_last_instruction(join->last_instruction());
-
-          // Resulting block must inherit block id from the eliminated current
-          // block to guarantee that ordering of phi operands in its successor
-          // stays consistent.
-          pred->set_block_id(block->block_id());
-
-          // If v1 and v2 were defined inside eliminated blocks pred1/pred2
-          // move them out to the place before inserted IfThenElse instruction.
-          EliminateTrivialBlock(pred1, v1->definition(), if_then_else);
-          EliminateTrivialBlock(pred2, v2->definition(), if_then_else);
-
-          // Update use lists to reflect changes in the graph.
-          phi->UnuseAllInputs();
-          branch->UnuseAllInputs();
-          block->UnuseAllInputs();
-
-          // The graph has changed. Recompute dominators and block orders after
-          // this pass is finished.
-          changed = true;
-        }
-      }
-    }
-  }
-
-  if (changed) {
-    // We may have changed the block order and the dominator tree.
-    flow_graph->DiscoverBlocks();
-    GrowableArray<BitVector*> dominance_frontier;
-    flow_graph->ComputeDominators(&dominance_frontier);
-  }
-}
-
-
-void FlowGraphOptimizer::EliminateEnvironments() {
-  // After this pass we can no longer perform LICM and hoist instructions
-  // that can deoptimize.
-
-  flow_graph_->disallow_licm();
-  for (intptr_t i = 0; i < block_order_.length(); ++i) {
-    BlockEntryInstr* block = block_order_[i];
-    block->RemoveEnvironment();
-    for (ForwardInstructionIterator it(block); !it.Done(); it.Advance()) {
-      Instruction* current = it.Current();
-      if (!current->CanDeoptimize()) {
-        // TODO(srdjan): --source-lines needs deopt environments to get at
-        // the code for this instruction, however, leaving the environment
-        // changes code.
-        current->RemoveEnvironment();
-      }
-    }
-  }
-}
-
-
-enum SafeUseCheck { kOptimisticCheck, kStrictCheck };
-
-// Check if the use is safe for allocation sinking. Allocation sinking
-// candidates can only be used at store instructions:
-//
-//     - any store into the allocation candidate itself is unconditionally safe
-//       as it just changes the rematerialization state of this candidate;
-//     - store into another object is only safe if another object is allocation
-//       candidate.
-//
-// We use a simple fix-point algorithm to discover the set of valid candidates
-// (see CollectCandidates method), that's why this IsSafeUse can operate in two
-// modes:
-//
-//     - optimistic, when every allocation is assumed to be an allocation
-//       sinking candidate;
-//     - strict, when only marked allocations are assumed to be allocation
-//       sinking candidates.
-//
-// Fix-point algorithm in CollectCandiates first collects a set of allocations
-// optimistically and then checks each collected candidate strictly and unmarks
-// invalid candidates transitively until only strictly valid ones remain.
-static bool IsSafeUse(Value* use, SafeUseCheck check_type) {
-  if (use->instruction()->IsMaterializeObject()) {
-    return true;
-  }
-
-  StoreInstanceFieldInstr* store = use->instruction()->AsStoreInstanceField();
-  if (store != NULL) {
-    if (use == store->value()) {
-      Definition* instance = store->instance()->definition();
-      return instance->IsAllocateObject() &&
-          ((check_type == kOptimisticCheck) ||
-           instance->Identity().IsAllocationSinkingCandidate());
-    }
-    return true;
-  }
-
-  return false;
-}
-
-
-// Right now we are attempting to sink allocation only into
-// deoptimization exit. So candidate should only be used in StoreInstanceField
-// instructions that write into fields of the allocated object.
-// We do not support materialization of the object that has type arguments.
-static bool IsAllocationSinkingCandidate(Definition* alloc,
-                                         SafeUseCheck check_type) {
-  for (Value* use = alloc->input_use_list();
-       use != NULL;
-       use = use->next_use()) {
-    if (!IsSafeUse(use, check_type)) {
-      if (FLAG_trace_optimization) {
-        OS::Print("use of %s at %s is unsafe for allocation sinking\n",
-                  alloc->ToCString(),
-                  use->instruction()->ToCString());
-      }
-      return false;
-    }
-  }
-
-  return true;
-}
-
-
-// If the given use is a store into an object then return an object we are
-// storing into.
-static Definition* StoreInto(Value* use) {
-  StoreInstanceFieldInstr* store = use->instruction()->AsStoreInstanceField();
-  if (store != NULL) {
-    return store->instance()->definition();
-  }
-
-  return NULL;
-}
-
-
-// Remove the given allocation from the graph. It is not observable.
-// If deoptimization occurs the object will be materialized.
-void AllocationSinking::EliminateAllocation(Definition* alloc) {
-  ASSERT(IsAllocationSinkingCandidate(alloc, kStrictCheck));
-
-  if (FLAG_trace_optimization) {
-    OS::Print("removing allocation from the graph: v%" Pd "\n",
-              alloc->ssa_temp_index());
-  }
-
-  // As an allocation sinking candidate it is only used in stores to its own
-  // fields. Remove these stores.
-  for (Value* use = alloc->input_use_list();
-       use != NULL;
-       use = alloc->input_use_list()) {
-    use->instruction()->RemoveFromGraph();
-  }
-
-  // There should be no environment uses. The pass replaced them with
-  // MaterializeObject instructions.
-#ifdef DEBUG
-  for (Value* use = alloc->env_use_list();
-       use != NULL;
-       use = use->next_use()) {
-    ASSERT(use->instruction()->IsMaterializeObject());
-  }
-#endif
-  ASSERT(alloc->input_use_list() == NULL);
-  alloc->RemoveFromGraph();
-  if (alloc->ArgumentCount() > 0) {
-    ASSERT(alloc->ArgumentCount() == 1);
-    for (intptr_t i = 0; i < alloc->ArgumentCount(); ++i) {
-      alloc->PushArgumentAt(i)->RemoveFromGraph();
-    }
-  }
-}
-
-
-// Find allocation instructions that can be potentially eliminated and
-// rematerialized at deoptimization exits if needed. See IsSafeUse
-// for the description of algorithm used below.
-void AllocationSinking::CollectCandidates() {
-  // Optimistically collect all potential candidates.
-  for (BlockIterator block_it = flow_graph_->reverse_postorder_iterator();
-       !block_it.Done();
-       block_it.Advance()) {
-    BlockEntryInstr* block = block_it.Current();
-    for (ForwardInstructionIterator it(block); !it.Done(); it.Advance()) {
-      { AllocateObjectInstr* alloc = it.Current()->AsAllocateObject();
-        if ((alloc != NULL) &&
-            IsAllocationSinkingCandidate(alloc, kOptimisticCheck)) {
-          alloc->SetIdentity(AliasIdentity::AllocationSinkingCandidate());
-          candidates_.Add(alloc);
-        }
-      }
-      { AllocateUninitializedContextInstr* alloc =
-            it.Current()->AsAllocateUninitializedContext();
-        if ((alloc != NULL) &&
-            IsAllocationSinkingCandidate(alloc, kOptimisticCheck)) {
-          alloc->SetIdentity(AliasIdentity::AllocationSinkingCandidate());
-          candidates_.Add(alloc);
-        }
-      }
-    }
-  }
-
-  // Transitively unmark all candidates that are not strictly valid.
-  bool changed;
-  do {
-    changed = false;
-    for (intptr_t i = 0; i < candidates_.length(); i++) {
-      Definition* alloc = candidates_[i];
-      if (alloc->Identity().IsAllocationSinkingCandidate()) {
-        if (!IsAllocationSinkingCandidate(alloc, kStrictCheck)) {
-          alloc->SetIdentity(AliasIdentity::Unknown());
-          changed = true;
-        }
-      }
-    }
-  } while (changed);
-
-  // Shrink the list of candidates removing all unmarked ones.
-  intptr_t j = 0;
-  for (intptr_t i = 0; i < candidates_.length(); i++) {
-    Definition* alloc = candidates_[i];
-    if (alloc->Identity().IsAllocationSinkingCandidate()) {
-      if (FLAG_trace_optimization) {
-        OS::Print("discovered allocation sinking candidate: v%" Pd "\n",
-                  alloc->ssa_temp_index());
-      }
-
-      if (j != i) {
-        candidates_[j] = alloc;
-      }
-      j++;
-    }
-  }
-  candidates_.TruncateTo(j);
-}
-
-
-// If materialization references an allocation sinking candidate then replace
-// this reference with a materialization which should have been computed for
-// this side-exit. CollectAllExits should have collected this exit.
-void AllocationSinking::NormalizeMaterializations() {
-  for (intptr_t i = 0; i < candidates_.length(); i++) {
-    Definition* alloc = candidates_[i];
-
-    Value* next_use;
-    for (Value* use = alloc->input_use_list();
-         use != NULL;
-         use = next_use) {
-      next_use = use->next_use();
-      if (use->instruction()->IsMaterializeObject()) {
-        use->BindTo(MaterializationFor(alloc, use->instruction()));
-      }
-    }
-  }
-}
-
-
-// We transitively insert materializations at each deoptimization exit that
-// might see the given allocation (see ExitsCollector). Some of this
-// materializations are not actually used and some fail to compute because
-// they are inserted in the block that is not dominated by the allocation.
-// Remove them unused materializations from the graph.
-void AllocationSinking::RemoveUnusedMaterializations() {
-  intptr_t j = 0;
-  for (intptr_t i = 0; i < materializations_.length(); i++) {
-    MaterializeObjectInstr* mat = materializations_[i];
-    if ((mat->input_use_list() == NULL) && (mat->env_use_list() == NULL)) {
-      // Check if this materialization failed to compute and remove any
-      // unforwarded loads. There were no loads from any allocation sinking
-      // candidate in the beggining so it is safe to assume that any encountered
-      // load was inserted by CreateMaterializationAt.
-      for (intptr_t i = 0; i < mat->InputCount(); i++) {
-        LoadFieldInstr* load = mat->InputAt(i)->definition()->AsLoadField();
-        if ((load != NULL) &&
-            (load->instance()->definition() == mat->allocation())) {
-          load->ReplaceUsesWith(flow_graph_->constant_null());
-          load->RemoveFromGraph();
-        }
-      }
-      mat->RemoveFromGraph();
-    } else {
-      if (j != i) {
-        materializations_[j] = mat;
-      }
-      j++;
-    }
-  }
-  materializations_.TruncateTo(j);
-}
-
-
-// Some candidates might stop being eligible for allocation sinking after
-// the load forwarding because they flow into phis that load forwarding
-// inserts. Discover such allocations and remove them from the list
-// of allocation sinking candidates undoing all changes that we did
-// in preparation for sinking these allocations.
-void AllocationSinking::DiscoverFailedCandidates() {
-  // Transitively unmark all candidates that are not strictly valid.
-  bool changed;
-  do {
-    changed = false;
-    for (intptr_t i = 0; i < candidates_.length(); i++) {
-      Definition* alloc = candidates_[i];
-      if (alloc->Identity().IsAllocationSinkingCandidate()) {
-        if (!IsAllocationSinkingCandidate(alloc, kStrictCheck)) {
-          alloc->SetIdentity(AliasIdentity::Unknown());
-          changed = true;
-        }
-      }
-    }
-  } while (changed);
-
-  // Remove all failed candidates from the candidates list.
-  intptr_t j = 0;
-  for (intptr_t i = 0; i < candidates_.length(); i++) {
-    Definition* alloc = candidates_[i];
-    if (!alloc->Identity().IsAllocationSinkingCandidate()) {
-      if (FLAG_trace_optimization) {
-        OS::Print("allocation v%" Pd " can't be eliminated\n",
-                  alloc->ssa_temp_index());
-      }
-
-#ifdef DEBUG
-      for (Value* use = alloc->env_use_list();
-           use != NULL;
-           use = use->next_use()) {
-        ASSERT(use->instruction()->IsMaterializeObject());
-      }
-#endif
-
-      // All materializations will be removed from the graph. Remove inserted
-      // loads first and detach materializations from allocation's environment
-      // use list: we will reconstruct it when we start removing
-      // materializations.
-      alloc->set_env_use_list(NULL);
-      for (Value* use = alloc->input_use_list();
-           use != NULL;
-           use = use->next_use()) {
-        if (use->instruction()->IsLoadField()) {
-          LoadFieldInstr* load = use->instruction()->AsLoadField();
-          load->ReplaceUsesWith(flow_graph_->constant_null());
-          load->RemoveFromGraph();
-        } else {
-          ASSERT(use->instruction()->IsMaterializeObject() ||
-                 use->instruction()->IsPhi() ||
-                 use->instruction()->IsStoreInstanceField());
-        }
-      }
-    } else {
-      if (j != i) {
-        candidates_[j] = alloc;
-      }
-      j++;
-    }
-  }
-
-  if (j != candidates_.length()) {  // Something was removed from candidates.
-    intptr_t k = 0;
-    for (intptr_t i = 0; i < materializations_.length(); i++) {
-      MaterializeObjectInstr* mat = materializations_[i];
-      if (!mat->allocation()->Identity().IsAllocationSinkingCandidate()) {
-        // Restore environment uses of the allocation that were replaced
-        // by this materialization and drop materialization.
-        mat->ReplaceUsesWith(mat->allocation());
-        mat->RemoveFromGraph();
-      } else {
-        if (k != i) {
-          materializations_[k] = mat;
-        }
-        k++;
-      }
-    }
-    materializations_.TruncateTo(k);
-  }
-
-  candidates_.TruncateTo(j);
-}
-
-
-void AllocationSinking::Optimize() {
-  CollectCandidates();
-
-  // Insert MaterializeObject instructions that will describe the state of the
-  // object at all deoptimization points. Each inserted materialization looks
-  // like this (where v_0 is allocation that we are going to eliminate):
-  //   v_1     <- LoadField(v_0, field_1)
-  //           ...
-  //   v_N     <- LoadField(v_0, field_N)
-  //   v_{N+1} <- MaterializeObject(field_1 = v_1, ..., field_N = v_{N})
-  for (intptr_t i = 0; i < candidates_.length(); i++) {
-    InsertMaterializations(candidates_[i]);
-  }
-
-  // Run load forwarding to eliminate LoadField instructions inserted above.
-  // All loads will be successfully eliminated because:
-  //   a) they use fields (not offsets) and thus provide precise aliasing
-  //      information
-  //   b) candidate does not escape and thus its fields is not affected by
-  //      external effects from calls.
-  LoadOptimizer::OptimizeGraph(flow_graph_);
-
-  NormalizeMaterializations();
-
-  RemoveUnusedMaterializations();
-
-  // If any candidates are no longer eligible for allocation sinking abort
-  // the optimization for them and undo any changes we did in preparation.
-  DiscoverFailedCandidates();
-
-  // At this point we have computed the state of object at each deoptimization
-  // point and we can eliminate it. Loads inserted above were forwarded so there
-  // are no uses of the allocation just as in the begging of the pass.
-  for (intptr_t i = 0; i < candidates_.length(); i++) {
-    EliminateAllocation(candidates_[i]);
-  }
-
-  // Process materializations and unbox their arguments: materializations
-  // are part of the environment and can materialize boxes for double/mint/simd
-  // values when needed.
-  // TODO(vegorov): handle all box types here.
-  for (intptr_t i = 0; i < materializations_.length(); i++) {
-    MaterializeObjectInstr* mat = materializations_[i];
-    for (intptr_t j = 0; j < mat->InputCount(); j++) {
-      Definition* defn = mat->InputAt(j)->definition();
-      if (defn->IsBox()) {
-        mat->InputAt(j)->BindTo(defn->InputAt(0)->definition());
-      }
-    }
-  }
-}
-
-
-// Remove materializations from the graph. Register allocator will treat them
-// as part of the environment not as a real instruction.
-void AllocationSinking::DetachMaterializations() {
-  for (intptr_t i = 0; i < materializations_.length(); i++) {
-    materializations_[i]->previous()->LinkTo(materializations_[i]->next());
-  }
-}
-
-
-// Add a field/offset to the list of fields if it is not yet present there.
-static bool AddSlot(ZoneGrowableArray<const Object*>* slots,
-                    const Object& slot) {
-  for (intptr_t i = 0; i < slots->length(); i++) {
-    if ((*slots)[i]->raw() == slot.raw()) {
-      return false;
-    }
-  }
-  slots->Add(&slot);
-  return true;
-}
-
-
-// Find deoptimization exit for the given materialization assuming that all
-// materializations are emitted right before the instruction which is a
-// deoptimization exit.
-static Instruction* ExitForMaterialization(MaterializeObjectInstr* mat) {
-  while (mat->next()->IsMaterializeObject()) {
-    mat = mat->next()->AsMaterializeObject();
-  }
-  return mat->next();
-}
-
-
-// Given the deoptimization exit find first materialization that was inserted
-// before it.
-static Instruction* FirstMaterializationAt(Instruction* exit) {
-  while (exit->previous()->IsMaterializeObject()) {
-    exit = exit->previous();
-  }
-  return exit;
-}
-
-
-// Given the allocation and deoptimization exit try to find MaterializeObject
-// instruction corresponding to this allocation at this exit.
-MaterializeObjectInstr* AllocationSinking::MaterializationFor(
-    Definition* alloc, Instruction* exit) {
-  if (exit->IsMaterializeObject()) {
-    exit = ExitForMaterialization(exit->AsMaterializeObject());
-  }
-
-  for (MaterializeObjectInstr* mat = exit->previous()->AsMaterializeObject();
-       mat != NULL;
-       mat = mat->previous()->AsMaterializeObject()) {
-    if (mat->allocation() == alloc) {
-      return mat;
-    }
-  }
-
-  return NULL;
-}
-
-
-// Insert MaterializeObject instruction for the given allocation before
-// the given instruction that can deoptimize.
-void AllocationSinking::CreateMaterializationAt(
-    Instruction* exit,
-    Definition* alloc,
-    const ZoneGrowableArray<const Object*>& slots) {
-  ZoneGrowableArray<Value*>* values =
-      new(I) ZoneGrowableArray<Value*>(slots.length());
-
-  // All loads should be inserted before the first materialization so that
-  // IR follows the following pattern: loads, materializations, deoptimizing
-  // instruction.
-  Instruction* load_point = FirstMaterializationAt(exit);
-
-  // Insert load instruction for every field.
-  for (intptr_t i = 0; i < slots.length(); i++) {
-    LoadFieldInstr* load = slots[i]->IsField()
-        ? new(I) LoadFieldInstr(
-            new(I) Value(alloc),
-            &Field::Cast(*slots[i]),
-            AbstractType::ZoneHandle(I),
-            alloc->token_pos())
-        : new(I) LoadFieldInstr(
-            new(I) Value(alloc),
-            Smi::Cast(*slots[i]).Value(),
-            AbstractType::ZoneHandle(I),
-            alloc->token_pos());
-    flow_graph_->InsertBefore(
-        load_point, load, NULL, FlowGraph::kValue);
-    values->Add(new(I) Value(load));
-  }
-
-  MaterializeObjectInstr* mat = NULL;
-  if (alloc->IsAllocateObject()) {
-    mat = new(I) MaterializeObjectInstr(
-        alloc->AsAllocateObject(), slots, values);
-  } else {
-    ASSERT(alloc->IsAllocateUninitializedContext());
-    mat = new(I) MaterializeObjectInstr(
-        alloc->AsAllocateUninitializedContext(), slots, values);
-  }
-
-  flow_graph_->InsertBefore(exit, mat, NULL, FlowGraph::kValue);
-
-  // Replace all mentions of this allocation with a newly inserted
-  // MaterializeObject instruction.
-  // We must preserve the identity: all mentions are replaced by the same
-  // materialization.
-  for (Environment::DeepIterator env_it(exit->env());
-       !env_it.Done();
-       env_it.Advance()) {
-    Value* use = env_it.CurrentValue();
-    if (use->definition() == alloc) {
-      use->RemoveFromUseList();
-      use->set_definition(mat);
-      mat->AddEnvUse(use);
-    }
-  }
-
-  // Mark MaterializeObject as an environment use of this allocation.
-  // This will allow us to discover it when we are looking for deoptimization
-  // exits for another allocation that potentially flows into this one.
-  Value* val = new(I) Value(alloc);
-  val->set_instruction(mat);
-  alloc->AddEnvUse(val);
-
-  // Record inserted materialization.
-  materializations_.Add(mat);
-}
-
-
-// Add given instruction to the list of the instructions if it is not yet
-// present there.
-template<typename T>
-void AddInstruction(GrowableArray<T*>* list, T* value) {
-  ASSERT(!value->IsGraphEntry());
-  for (intptr_t i = 0; i < list->length(); i++) {
-    if ((*list)[i] == value) {
-      return;
-    }
-  }
-  list->Add(value);
-}
-
-
-// Transitively collect all deoptimization exits that might need this allocation
-// rematerialized. It is not enough to collect only environment uses of this
-// allocation because it can flow into other objects that will be
-// dematerialized and that are referenced by deopt environments that
-// don't contain this allocation explicitly.
-void AllocationSinking::ExitsCollector::Collect(Definition* alloc) {
-  for (Value* use = alloc->env_use_list();
-       use != NULL;
-       use = use->next_use()) {
-    if (use->instruction()->IsMaterializeObject()) {
-      AddInstruction(&exits_, ExitForMaterialization(
-          use->instruction()->AsMaterializeObject()));
-    } else {
-      AddInstruction(&exits_, use->instruction());
-    }
-  }
-
-  // Check if this allocation is stored into any other allocation sinking
-  // candidate and put it on worklist so that we conservatively collect all
-  // exits for that candidate as well because they potentially might see
-  // this object.
-  for (Value* use = alloc->input_use_list();
-       use != NULL;
-       use = use->next_use()) {
-    Definition* obj = StoreInto(use);
-    if ((obj != NULL) && (obj != alloc)) {
-      AddInstruction(&worklist_, obj);
-    }
-  }
-}
-
-
-void AllocationSinking::ExitsCollector::CollectTransitively(Definition* alloc) {
-  exits_.TruncateTo(0);
-  worklist_.TruncateTo(0);
-
-  worklist_.Add(alloc);
-
-  // Note: worklist potentially will grow while we are iterating over it.
-  // We are not removing allocations from the worklist not to waste space on
-  // the side maintaining BitVector of already processed allocations: worklist
-  // is expected to be very small thus linear search in it is just as effecient
-  // as a bitvector.
-  for (intptr_t i = 0; i < worklist_.length(); i++) {
-    Collect(worklist_[i]);
-  }
-}
-
-
-void AllocationSinking::InsertMaterializations(Definition* alloc) {
-  // Collect all fields that are written for this instance.
-  ZoneGrowableArray<const Object*>* slots =
-      new(I) ZoneGrowableArray<const Object*>(5);
-
-  for (Value* use = alloc->input_use_list();
-       use != NULL;
-       use = use->next_use()) {
-    StoreInstanceFieldInstr* store = use->instruction()->AsStoreInstanceField();
-    if ((store != NULL) && (store->instance()->definition() == alloc)) {
-      if (!store->field().IsNull()) {
-        AddSlot(slots, store->field());
-      } else {
-        AddSlot(slots, Smi::ZoneHandle(I, Smi::New(store->offset_in_bytes())));
-      }
-    }
-  }
-
-  if (alloc->ArgumentCount() > 0) {
-    AllocateObjectInstr* alloc_object = alloc->AsAllocateObject();
-    ASSERT(alloc_object->ArgumentCount() == 1);
-    intptr_t type_args_offset =
-        alloc_object->cls().type_arguments_field_offset();
-    AddSlot(slots, Smi::ZoneHandle(I, Smi::New(type_args_offset)));
-  }
-
-  // Collect all instructions that mention this object in the environment.
-  exits_collector_.CollectTransitively(alloc);
-
-  // Insert materializations at environment uses.
-  for (intptr_t i = 0; i < exits_collector_.exits().length(); i++) {
-    CreateMaterializationAt(
-        exits_collector_.exits()[i], alloc, *slots);
-  }
-}
-
-
 }  // namespace dart