Upgrade to 3.29

Update V8 to 3.29.88.17 and update makefiles to support building on
all the relevant platforms.

Bug: 17370214

Change-Id: Ia3407c157fd8d72a93e23d8318ccaf6ecf77fa4e
diff --git a/src/arm64/code-stubs-arm64.cc b/src/arm64/code-stubs-arm64.cc
new file mode 100644
index 0000000..4978e5e
--- /dev/null
+++ b/src/arm64/code-stubs-arm64.cc
@@ -0,0 +1,5069 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/v8.h"
+
+#if V8_TARGET_ARCH_ARM64
+
+#include "src/bootstrapper.h"
+#include "src/code-stubs.h"
+#include "src/codegen.h"
+#include "src/ic/handler-compiler.h"
+#include "src/ic/ic.h"
+#include "src/isolate.h"
+#include "src/jsregexp.h"
+#include "src/regexp-macro-assembler.h"
+#include "src/runtime.h"
+
+namespace v8 {
+namespace internal {
+
+
+static void InitializeArrayConstructorDescriptor(
+    Isolate* isolate, CodeStubDescriptor* descriptor,
+    int constant_stack_parameter_count) {
+  // cp: context
+  // x1: function
+  // x2: allocation site with elements kind
+  // x0: number of arguments to the constructor function
+  Address deopt_handler = Runtime::FunctionForId(
+      Runtime::kArrayConstructor)->entry;
+
+  if (constant_stack_parameter_count == 0) {
+    descriptor->Initialize(deopt_handler, constant_stack_parameter_count,
+                           JS_FUNCTION_STUB_MODE);
+  } else {
+    descriptor->Initialize(x0, deopt_handler, constant_stack_parameter_count,
+                           JS_FUNCTION_STUB_MODE, PASS_ARGUMENTS);
+  }
+}
+
+
+void ArrayNoArgumentConstructorStub::InitializeDescriptor(
+    CodeStubDescriptor* descriptor) {
+  InitializeArrayConstructorDescriptor(isolate(), descriptor, 0);
+}
+
+
+void ArraySingleArgumentConstructorStub::InitializeDescriptor(
+    CodeStubDescriptor* descriptor) {
+  InitializeArrayConstructorDescriptor(isolate(), descriptor, 1);
+}
+
+
+void ArrayNArgumentsConstructorStub::InitializeDescriptor(
+    CodeStubDescriptor* descriptor) {
+  InitializeArrayConstructorDescriptor(isolate(), descriptor, -1);
+}
+
+
+static void InitializeInternalArrayConstructorDescriptor(
+    Isolate* isolate, CodeStubDescriptor* descriptor,
+    int constant_stack_parameter_count) {
+  Address deopt_handler = Runtime::FunctionForId(
+      Runtime::kInternalArrayConstructor)->entry;
+
+  if (constant_stack_parameter_count == 0) {
+    descriptor->Initialize(deopt_handler, constant_stack_parameter_count,
+                           JS_FUNCTION_STUB_MODE);
+  } else {
+    descriptor->Initialize(x0, deopt_handler, constant_stack_parameter_count,
+                           JS_FUNCTION_STUB_MODE, PASS_ARGUMENTS);
+  }
+}
+
+
+void InternalArrayNoArgumentConstructorStub::InitializeDescriptor(
+    CodeStubDescriptor* descriptor) {
+  InitializeInternalArrayConstructorDescriptor(isolate(), descriptor, 0);
+}
+
+
+void InternalArraySingleArgumentConstructorStub::InitializeDescriptor(
+    CodeStubDescriptor* descriptor) {
+  InitializeInternalArrayConstructorDescriptor(isolate(), descriptor, 1);
+}
+
+
+void InternalArrayNArgumentsConstructorStub::InitializeDescriptor(
+    CodeStubDescriptor* descriptor) {
+  InitializeInternalArrayConstructorDescriptor(isolate(), descriptor, -1);
+}
+
+
+#define __ ACCESS_MASM(masm)
+
+
+void HydrogenCodeStub::GenerateLightweightMiss(MacroAssembler* masm,
+                                               ExternalReference miss) {
+  // Update the static counter each time a new code stub is generated.
+  isolate()->counters()->code_stubs()->Increment();
+
+  CallInterfaceDescriptor descriptor = GetCallInterfaceDescriptor();
+  int param_count = descriptor.GetEnvironmentParameterCount();
+  {
+    // Call the runtime system in a fresh internal frame.
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    DCHECK((param_count == 0) ||
+           x0.Is(descriptor.GetEnvironmentParameterRegister(param_count - 1)));
+
+    // Push arguments
+    MacroAssembler::PushPopQueue queue(masm);
+    for (int i = 0; i < param_count; ++i) {
+      queue.Queue(descriptor.GetEnvironmentParameterRegister(i));
+    }
+    queue.PushQueued();
+
+    __ CallExternalReference(miss, param_count);
+  }
+
+  __ Ret();
+}
+
+
+void DoubleToIStub::Generate(MacroAssembler* masm) {
+  Label done;
+  Register input = source();
+  Register result = destination();
+  DCHECK(is_truncating());
+
+  DCHECK(result.Is64Bits());
+  DCHECK(jssp.Is(masm->StackPointer()));
+
+  int double_offset = offset();
+
+  DoubleRegister double_scratch = d0;  // only used if !skip_fastpath()
+  Register scratch1 = GetAllocatableRegisterThatIsNotOneOf(input, result);
+  Register scratch2 =
+      GetAllocatableRegisterThatIsNotOneOf(input, result, scratch1);
+
+  __ Push(scratch1, scratch2);
+  // Account for saved regs if input is jssp.
+  if (input.is(jssp)) double_offset += 2 * kPointerSize;
+
+  if (!skip_fastpath()) {
+    __ Push(double_scratch);
+    if (input.is(jssp)) double_offset += 1 * kDoubleSize;
+    __ Ldr(double_scratch, MemOperand(input, double_offset));
+    // Try to convert with a FPU convert instruction.  This handles all
+    // non-saturating cases.
+    __ TryConvertDoubleToInt64(result, double_scratch, &done);
+    __ Fmov(result, double_scratch);
+  } else {
+    __ Ldr(result, MemOperand(input, double_offset));
+  }
+
+  // If we reach here we need to manually convert the input to an int32.
+
+  // Extract the exponent.
+  Register exponent = scratch1;
+  __ Ubfx(exponent, result, HeapNumber::kMantissaBits,
+          HeapNumber::kExponentBits);
+
+  // It the exponent is >= 84 (kMantissaBits + 32), the result is always 0 since
+  // the mantissa gets shifted completely out of the int32_t result.
+  __ Cmp(exponent, HeapNumber::kExponentBias + HeapNumber::kMantissaBits + 32);
+  __ CzeroX(result, ge);
+  __ B(ge, &done);
+
+  // The Fcvtzs sequence handles all cases except where the conversion causes
+  // signed overflow in the int64_t target. Since we've already handled
+  // exponents >= 84, we can guarantee that 63 <= exponent < 84.
+
+  if (masm->emit_debug_code()) {
+    __ Cmp(exponent, HeapNumber::kExponentBias + 63);
+    // Exponents less than this should have been handled by the Fcvt case.
+    __ Check(ge, kUnexpectedValue);
+  }
+
+  // Isolate the mantissa bits, and set the implicit '1'.
+  Register mantissa = scratch2;
+  __ Ubfx(mantissa, result, 0, HeapNumber::kMantissaBits);
+  __ Orr(mantissa, mantissa, 1UL << HeapNumber::kMantissaBits);
+
+  // Negate the mantissa if necessary.
+  __ Tst(result, kXSignMask);
+  __ Cneg(mantissa, mantissa, ne);
+
+  // Shift the mantissa bits in the correct place. We know that we have to shift
+  // it left here, because exponent >= 63 >= kMantissaBits.
+  __ Sub(exponent, exponent,
+         HeapNumber::kExponentBias + HeapNumber::kMantissaBits);
+  __ Lsl(result, mantissa, exponent);
+
+  __ Bind(&done);
+  if (!skip_fastpath()) {
+    __ Pop(double_scratch);
+  }
+  __ Pop(scratch2, scratch1);
+  __ Ret();
+}
+
+
+// See call site for description.
+static void EmitIdenticalObjectComparison(MacroAssembler* masm,
+                                          Register left,
+                                          Register right,
+                                          Register scratch,
+                                          FPRegister double_scratch,
+                                          Label* slow,
+                                          Condition cond) {
+  DCHECK(!AreAliased(left, right, scratch));
+  Label not_identical, return_equal, heap_number;
+  Register result = x0;
+
+  __ Cmp(right, left);
+  __ B(ne, &not_identical);
+
+  // Test for NaN. Sadly, we can't just compare to factory::nan_value(),
+  // so we do the second best thing - test it ourselves.
+  // They are both equal and they are not both Smis so both of them are not
+  // Smis.  If it's not a heap number, then return equal.
+  if ((cond == lt) || (cond == gt)) {
+    __ JumpIfObjectType(right, scratch, scratch, FIRST_SPEC_OBJECT_TYPE, slow,
+                        ge);
+  } else if (cond == eq) {
+    __ JumpIfHeapNumber(right, &heap_number);
+  } else {
+    Register right_type = scratch;
+    __ JumpIfObjectType(right, right_type, right_type, HEAP_NUMBER_TYPE,
+                        &heap_number);
+    // Comparing JS objects with <=, >= is complicated.
+    __ Cmp(right_type, FIRST_SPEC_OBJECT_TYPE);
+    __ B(ge, slow);
+    // Normally here we fall through to return_equal, but undefined is
+    // special: (undefined == undefined) == true, but
+    // (undefined <= undefined) == false!  See ECMAScript 11.8.5.
+    if ((cond == le) || (cond == ge)) {
+      __ Cmp(right_type, ODDBALL_TYPE);
+      __ B(ne, &return_equal);
+      __ JumpIfNotRoot(right, Heap::kUndefinedValueRootIndex, &return_equal);
+      if (cond == le) {
+        // undefined <= undefined should fail.
+        __ Mov(result, GREATER);
+      } else {
+        // undefined >= undefined should fail.
+        __ Mov(result, LESS);
+      }
+      __ Ret();
+    }
+  }
+
+  __ Bind(&return_equal);
+  if (cond == lt) {
+    __ Mov(result, GREATER);  // Things aren't less than themselves.
+  } else if (cond == gt) {
+    __ Mov(result, LESS);     // Things aren't greater than themselves.
+  } else {
+    __ Mov(result, EQUAL);    // Things are <=, >=, ==, === themselves.
+  }
+  __ Ret();
+
+  // Cases lt and gt have been handled earlier, and case ne is never seen, as
+  // it is handled in the parser (see Parser::ParseBinaryExpression). We are
+  // only concerned with cases ge, le and eq here.
+  if ((cond != lt) && (cond != gt)) {
+    DCHECK((cond == ge) || (cond == le) || (cond == eq));
+    __ Bind(&heap_number);
+    // Left and right are identical pointers to a heap number object. Return
+    // non-equal if the heap number is a NaN, and equal otherwise. Comparing
+    // the number to itself will set the overflow flag iff the number is NaN.
+    __ Ldr(double_scratch, FieldMemOperand(right, HeapNumber::kValueOffset));
+    __ Fcmp(double_scratch, double_scratch);
+    __ B(vc, &return_equal);  // Not NaN, so treat as normal heap number.
+
+    if (cond == le) {
+      __ Mov(result, GREATER);
+    } else {
+      __ Mov(result, LESS);
+    }
+    __ Ret();
+  }
+
+  // No fall through here.
+  if (FLAG_debug_code) {
+    __ Unreachable();
+  }
+
+  __ Bind(&not_identical);
+}
+
+
+// See call site for description.
+static void EmitStrictTwoHeapObjectCompare(MacroAssembler* masm,
+                                           Register left,
+                                           Register right,
+                                           Register left_type,
+                                           Register right_type,
+                                           Register scratch) {
+  DCHECK(!AreAliased(left, right, left_type, right_type, scratch));
+
+  if (masm->emit_debug_code()) {
+    // We assume that the arguments are not identical.
+    __ Cmp(left, right);
+    __ Assert(ne, kExpectedNonIdenticalObjects);
+  }
+
+  // If either operand is a JS object or an oddball value, then they are not
+  // equal since their pointers are different.
+  // There is no test for undetectability in strict equality.
+  STATIC_ASSERT(LAST_TYPE == LAST_SPEC_OBJECT_TYPE);
+  Label right_non_object;
+
+  __ Cmp(right_type, FIRST_SPEC_OBJECT_TYPE);
+  __ B(lt, &right_non_object);
+
+  // Return non-zero - x0 already contains a non-zero pointer.
+  DCHECK(left.is(x0) || right.is(x0));
+  Label return_not_equal;
+  __ Bind(&return_not_equal);
+  __ Ret();
+
+  __ Bind(&right_non_object);
+
+  // Check for oddballs: true, false, null, undefined.
+  __ Cmp(right_type, ODDBALL_TYPE);
+
+  // If right is not ODDBALL, test left. Otherwise, set eq condition.
+  __ Ccmp(left_type, ODDBALL_TYPE, ZFlag, ne);
+
+  // If right or left is not ODDBALL, test left >= FIRST_SPEC_OBJECT_TYPE.
+  // Otherwise, right or left is ODDBALL, so set a ge condition.
+  __ Ccmp(left_type, FIRST_SPEC_OBJECT_TYPE, NVFlag, ne);
+
+  __ B(ge, &return_not_equal);
+
+  // Internalized strings are unique, so they can only be equal if they are the
+  // same object. We have already tested that case, so if left and right are
+  // both internalized strings, they cannot be equal.
+  STATIC_ASSERT((kInternalizedTag == 0) && (kStringTag == 0));
+  __ Orr(scratch, left_type, right_type);
+  __ TestAndBranchIfAllClear(
+      scratch, kIsNotStringMask | kIsNotInternalizedMask, &return_not_equal);
+}
+
+
+// See call site for description.
+static void EmitSmiNonsmiComparison(MacroAssembler* masm,
+                                    Register left,
+                                    Register right,
+                                    FPRegister left_d,
+                                    FPRegister right_d,
+                                    Label* slow,
+                                    bool strict) {
+  DCHECK(!AreAliased(left_d, right_d));
+  DCHECK((left.is(x0) && right.is(x1)) ||
+         (right.is(x0) && left.is(x1)));
+  Register result = x0;
+
+  Label right_is_smi, done;
+  __ JumpIfSmi(right, &right_is_smi);
+
+  // Left is the smi. Check whether right is a heap number.
+  if (strict) {
+    // If right is not a number and left is a smi, then strict equality cannot
+    // succeed. Return non-equal.
+    Label is_heap_number;
+    __ JumpIfHeapNumber(right, &is_heap_number);
+    // Register right is a non-zero pointer, which is a valid NOT_EQUAL result.
+    if (!right.is(result)) {
+      __ Mov(result, NOT_EQUAL);
+    }
+    __ Ret();
+    __ Bind(&is_heap_number);
+  } else {
+    // Smi compared non-strictly with a non-smi, non-heap-number. Call the
+    // runtime.
+    __ JumpIfNotHeapNumber(right, slow);
+  }
+
+  // Left is the smi. Right is a heap number. Load right value into right_d, and
+  // convert left smi into double in left_d.
+  __ Ldr(right_d, FieldMemOperand(right, HeapNumber::kValueOffset));
+  __ SmiUntagToDouble(left_d, left);
+  __ B(&done);
+
+  __ Bind(&right_is_smi);
+  // Right is a smi. Check whether the non-smi left is a heap number.
+  if (strict) {
+    // If left is not a number and right is a smi then strict equality cannot
+    // succeed. Return non-equal.
+    Label is_heap_number;
+    __ JumpIfHeapNumber(left, &is_heap_number);
+    // Register left is a non-zero pointer, which is a valid NOT_EQUAL result.
+    if (!left.is(result)) {
+      __ Mov(result, NOT_EQUAL);
+    }
+    __ Ret();
+    __ Bind(&is_heap_number);
+  } else {
+    // Smi compared non-strictly with a non-smi, non-heap-number. Call the
+    // runtime.
+    __ JumpIfNotHeapNumber(left, slow);
+  }
+
+  // Right is the smi. Left is a heap number. Load left value into left_d, and
+  // convert right smi into double in right_d.
+  __ Ldr(left_d, FieldMemOperand(left, HeapNumber::kValueOffset));
+  __ SmiUntagToDouble(right_d, right);
+
+  // Fall through to both_loaded_as_doubles.
+  __ Bind(&done);
+}
+
+
+// Fast negative check for internalized-to-internalized equality.
+// See call site for description.
+static void EmitCheckForInternalizedStringsOrObjects(MacroAssembler* masm,
+                                                     Register left,
+                                                     Register right,
+                                                     Register left_map,
+                                                     Register right_map,
+                                                     Register left_type,
+                                                     Register right_type,
+                                                     Label* possible_strings,
+                                                     Label* not_both_strings) {
+  DCHECK(!AreAliased(left, right, left_map, right_map, left_type, right_type));
+  Register result = x0;
+
+  Label object_test;
+  STATIC_ASSERT((kInternalizedTag == 0) && (kStringTag == 0));
+  // TODO(all): reexamine this branch sequence for optimisation wrt branch
+  // prediction.
+  __ Tbnz(right_type, MaskToBit(kIsNotStringMask), &object_test);
+  __ Tbnz(right_type, MaskToBit(kIsNotInternalizedMask), possible_strings);
+  __ Tbnz(left_type, MaskToBit(kIsNotStringMask), not_both_strings);
+  __ Tbnz(left_type, MaskToBit(kIsNotInternalizedMask), possible_strings);
+
+  // Both are internalized. We already checked that they weren't the same
+  // pointer, so they are not equal.
+  __ Mov(result, NOT_EQUAL);
+  __ Ret();
+
+  __ Bind(&object_test);
+
+  __ Cmp(right_type, FIRST_SPEC_OBJECT_TYPE);
+
+  // If right >= FIRST_SPEC_OBJECT_TYPE, test left.
+  // Otherwise, right < FIRST_SPEC_OBJECT_TYPE, so set lt condition.
+  __ Ccmp(left_type, FIRST_SPEC_OBJECT_TYPE, NFlag, ge);
+
+  __ B(lt, not_both_strings);
+
+  // If both objects are undetectable, they are equal. Otherwise, they are not
+  // equal, since they are different objects and an object is not equal to
+  // undefined.
+
+  // Returning here, so we can corrupt right_type and left_type.
+  Register right_bitfield = right_type;
+  Register left_bitfield = left_type;
+  __ Ldrb(right_bitfield, FieldMemOperand(right_map, Map::kBitFieldOffset));
+  __ Ldrb(left_bitfield, FieldMemOperand(left_map, Map::kBitFieldOffset));
+  __ And(result, right_bitfield, left_bitfield);
+  __ And(result, result, 1 << Map::kIsUndetectable);
+  __ Eor(result, result, 1 << Map::kIsUndetectable);
+  __ Ret();
+}
+
+
+static void CompareICStub_CheckInputType(MacroAssembler* masm, Register input,
+                                         CompareICState::State expected,
+                                         Label* fail) {
+  Label ok;
+  if (expected == CompareICState::SMI) {
+    __ JumpIfNotSmi(input, fail);
+  } else if (expected == CompareICState::NUMBER) {
+    __ JumpIfSmi(input, &ok);
+    __ JumpIfNotHeapNumber(input, fail);
+  }
+  // We could be strict about internalized/non-internalized here, but as long as
+  // hydrogen doesn't care, the stub doesn't have to care either.
+  __ Bind(&ok);
+}
+
+
+void CompareICStub::GenerateGeneric(MacroAssembler* masm) {
+  Register lhs = x1;
+  Register rhs = x0;
+  Register result = x0;
+  Condition cond = GetCondition();
+
+  Label miss;
+  CompareICStub_CheckInputType(masm, lhs, left(), &miss);
+  CompareICStub_CheckInputType(masm, rhs, right(), &miss);
+
+  Label slow;  // Call builtin.
+  Label not_smis, both_loaded_as_doubles;
+  Label not_two_smis, smi_done;
+  __ JumpIfEitherNotSmi(lhs, rhs, &not_two_smis);
+  __ SmiUntag(lhs);
+  __ Sub(result, lhs, Operand::UntagSmi(rhs));
+  __ Ret();
+
+  __ Bind(&not_two_smis);
+
+  // NOTICE! This code is only reached after a smi-fast-case check, so it is
+  // certain that at least one operand isn't a smi.
+
+  // Handle the case where the objects are identical. Either returns the answer
+  // or goes to slow. Only falls through if the objects were not identical.
+  EmitIdenticalObjectComparison(masm, lhs, rhs, x10, d0, &slow, cond);
+
+  // If either is a smi (we know that at least one is not a smi), then they can
+  // only be strictly equal if the other is a HeapNumber.
+  __ JumpIfBothNotSmi(lhs, rhs, &not_smis);
+
+  // Exactly one operand is a smi. EmitSmiNonsmiComparison generates code that
+  // can:
+  //  1) Return the answer.
+  //  2) Branch to the slow case.
+  //  3) Fall through to both_loaded_as_doubles.
+  // In case 3, we have found out that we were dealing with a number-number
+  // comparison. The double values of the numbers have been loaded, right into
+  // rhs_d, left into lhs_d.
+  FPRegister rhs_d = d0;
+  FPRegister lhs_d = d1;
+  EmitSmiNonsmiComparison(masm, lhs, rhs, lhs_d, rhs_d, &slow, strict());
+
+  __ Bind(&both_loaded_as_doubles);
+  // The arguments have been converted to doubles and stored in rhs_d and
+  // lhs_d.
+  Label nan;
+  __ Fcmp(lhs_d, rhs_d);
+  __ B(vs, &nan);  // Overflow flag set if either is NaN.
+  STATIC_ASSERT((LESS == -1) && (EQUAL == 0) && (GREATER == 1));
+  __ Cset(result, gt);  // gt => 1, otherwise (lt, eq) => 0 (EQUAL).
+  __ Csinv(result, result, xzr, ge);  // lt => -1, gt => 1, eq => 0.
+  __ Ret();
+
+  __ Bind(&nan);
+  // Left and/or right is a NaN. Load the result register with whatever makes
+  // the comparison fail, since comparisons with NaN always fail (except ne,
+  // which is filtered out at a higher level.)
+  DCHECK(cond != ne);
+  if ((cond == lt) || (cond == le)) {
+    __ Mov(result, GREATER);
+  } else {
+    __ Mov(result, LESS);
+  }
+  __ Ret();
+
+  __ Bind(&not_smis);
+  // At this point we know we are dealing with two different objects, and
+  // neither of them is a smi. The objects are in rhs_ and lhs_.
+
+  // Load the maps and types of the objects.
+  Register rhs_map = x10;
+  Register rhs_type = x11;
+  Register lhs_map = x12;
+  Register lhs_type = x13;
+  __ Ldr(rhs_map, FieldMemOperand(rhs, HeapObject::kMapOffset));
+  __ Ldr(lhs_map, FieldMemOperand(lhs, HeapObject::kMapOffset));
+  __ Ldrb(rhs_type, FieldMemOperand(rhs_map, Map::kInstanceTypeOffset));
+  __ Ldrb(lhs_type, FieldMemOperand(lhs_map, Map::kInstanceTypeOffset));
+
+  if (strict()) {
+    // This emits a non-equal return sequence for some object types, or falls
+    // through if it was not lucky.
+    EmitStrictTwoHeapObjectCompare(masm, lhs, rhs, lhs_type, rhs_type, x14);
+  }
+
+  Label check_for_internalized_strings;
+  Label flat_string_check;
+  // Check for heap number comparison. Branch to earlier double comparison code
+  // if they are heap numbers, otherwise, branch to internalized string check.
+  __ Cmp(rhs_type, HEAP_NUMBER_TYPE);
+  __ B(ne, &check_for_internalized_strings);
+  __ Cmp(lhs_map, rhs_map);
+
+  // If maps aren't equal, lhs_ and rhs_ are not heap numbers. Branch to flat
+  // string check.
+  __ B(ne, &flat_string_check);
+
+  // Both lhs_ and rhs_ are heap numbers. Load them and branch to the double
+  // comparison code.
+  __ Ldr(lhs_d, FieldMemOperand(lhs, HeapNumber::kValueOffset));
+  __ Ldr(rhs_d, FieldMemOperand(rhs, HeapNumber::kValueOffset));
+  __ B(&both_loaded_as_doubles);
+
+  __ Bind(&check_for_internalized_strings);
+  // In the strict case, the EmitStrictTwoHeapObjectCompare already took care
+  // of internalized strings.
+  if ((cond == eq) && !strict()) {
+    // Returns an answer for two internalized strings or two detectable objects.
+    // Otherwise branches to the string case or not both strings case.
+    EmitCheckForInternalizedStringsOrObjects(masm, lhs, rhs, lhs_map, rhs_map,
+                                             lhs_type, rhs_type,
+                                             &flat_string_check, &slow);
+  }
+
+  // Check for both being sequential one-byte strings,
+  // and inline if that is the case.
+  __ Bind(&flat_string_check);
+  __ JumpIfBothInstanceTypesAreNotSequentialOneByte(lhs_type, rhs_type, x14,
+                                                    x15, &slow);
+
+  __ IncrementCounter(isolate()->counters()->string_compare_native(), 1, x10,
+                      x11);
+  if (cond == eq) {
+    StringHelper::GenerateFlatOneByteStringEquals(masm, lhs, rhs, x10, x11,
+                                                  x12);
+  } else {
+    StringHelper::GenerateCompareFlatOneByteStrings(masm, lhs, rhs, x10, x11,
+                                                    x12, x13);
+  }
+
+  // Never fall through to here.
+  if (FLAG_debug_code) {
+    __ Unreachable();
+  }
+
+  __ Bind(&slow);
+
+  __ Push(lhs, rhs);
+  // Figure out which native to call and setup the arguments.
+  Builtins::JavaScript native;
+  if (cond == eq) {
+    native = strict() ? Builtins::STRICT_EQUALS : Builtins::EQUALS;
+  } else {
+    native = Builtins::COMPARE;
+    int ncr;  // NaN compare result
+    if ((cond == lt) || (cond == le)) {
+      ncr = GREATER;
+    } else {
+      DCHECK((cond == gt) || (cond == ge));  // remaining cases
+      ncr = LESS;
+    }
+    __ Mov(x10, Smi::FromInt(ncr));
+    __ Push(x10);
+  }
+
+  // Call the native; it returns -1 (less), 0 (equal), or 1 (greater)
+  // tagged as a small integer.
+  __ InvokeBuiltin(native, JUMP_FUNCTION);
+
+  __ Bind(&miss);
+  GenerateMiss(masm);
+}
+
+
+void StoreBufferOverflowStub::Generate(MacroAssembler* masm) {
+  CPURegList saved_regs = kCallerSaved;
+  CPURegList saved_fp_regs = kCallerSavedFP;
+
+  // We don't allow a GC during a store buffer overflow so there is no need to
+  // store the registers in any particular way, but we do have to store and
+  // restore them.
+
+  // We don't care if MacroAssembler scratch registers are corrupted.
+  saved_regs.Remove(*(masm->TmpList()));
+  saved_fp_regs.Remove(*(masm->FPTmpList()));
+
+  __ PushCPURegList(saved_regs);
+  if (save_doubles()) {
+    __ PushCPURegList(saved_fp_regs);
+  }
+
+  AllowExternalCallThatCantCauseGC scope(masm);
+  __ Mov(x0, ExternalReference::isolate_address(isolate()));
+  __ CallCFunction(
+      ExternalReference::store_buffer_overflow_function(isolate()), 1, 0);
+
+  if (save_doubles()) {
+    __ PopCPURegList(saved_fp_regs);
+  }
+  __ PopCPURegList(saved_regs);
+  __ Ret();
+}
+
+
+void StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime(
+    Isolate* isolate) {
+  StoreBufferOverflowStub stub1(isolate, kDontSaveFPRegs);
+  stub1.GetCode();
+  StoreBufferOverflowStub stub2(isolate, kSaveFPRegs);
+  stub2.GetCode();
+}
+
+
+void StoreRegistersStateStub::Generate(MacroAssembler* masm) {
+  MacroAssembler::NoUseRealAbortsScope no_use_real_aborts(masm);
+  UseScratchRegisterScope temps(masm);
+  Register saved_lr = temps.UnsafeAcquire(to_be_pushed_lr());
+  Register return_address = temps.AcquireX();
+  __ Mov(return_address, lr);
+  // Restore lr with the value it had before the call to this stub (the value
+  // which must be pushed).
+  __ Mov(lr, saved_lr);
+  __ PushSafepointRegisters();
+  __ Ret(return_address);
+}
+
+
+void RestoreRegistersStateStub::Generate(MacroAssembler* masm) {
+  MacroAssembler::NoUseRealAbortsScope no_use_real_aborts(masm);
+  UseScratchRegisterScope temps(masm);
+  Register return_address = temps.AcquireX();
+  // Preserve the return address (lr will be clobbered by the pop).
+  __ Mov(return_address, lr);
+  __ PopSafepointRegisters();
+  __ Ret(return_address);
+}
+
+
+void MathPowStub::Generate(MacroAssembler* masm) {
+  // Stack on entry:
+  // jssp[0]: Exponent (as a tagged value).
+  // jssp[1]: Base (as a tagged value).
+  //
+  // The (tagged) result will be returned in x0, as a heap number.
+
+  Register result_tagged = x0;
+  Register base_tagged = x10;
+  Register exponent_tagged = MathPowTaggedDescriptor::exponent();
+  DCHECK(exponent_tagged.is(x11));
+  Register exponent_integer = MathPowIntegerDescriptor::exponent();
+  DCHECK(exponent_integer.is(x12));
+  Register scratch1 = x14;
+  Register scratch0 = x15;
+  Register saved_lr = x19;
+  FPRegister result_double = d0;
+  FPRegister base_double = d0;
+  FPRegister exponent_double = d1;
+  FPRegister base_double_copy = d2;
+  FPRegister scratch1_double = d6;
+  FPRegister scratch0_double = d7;
+
+  // A fast-path for integer exponents.
+  Label exponent_is_smi, exponent_is_integer;
+  // Bail out to runtime.
+  Label call_runtime;
+  // Allocate a heap number for the result, and return it.
+  Label done;
+
+  // Unpack the inputs.
+  if (exponent_type() == ON_STACK) {
+    Label base_is_smi;
+    Label unpack_exponent;
+
+    __ Pop(exponent_tagged, base_tagged);
+
+    __ JumpIfSmi(base_tagged, &base_is_smi);
+    __ JumpIfNotHeapNumber(base_tagged, &call_runtime);
+    // base_tagged is a heap number, so load its double value.
+    __ Ldr(base_double, FieldMemOperand(base_tagged, HeapNumber::kValueOffset));
+    __ B(&unpack_exponent);
+    __ Bind(&base_is_smi);
+    // base_tagged is a SMI, so untag it and convert it to a double.
+    __ SmiUntagToDouble(base_double, base_tagged);
+
+    __ Bind(&unpack_exponent);
+    //  x10   base_tagged       The tagged base (input).
+    //  x11   exponent_tagged   The tagged exponent (input).
+    //  d1    base_double       The base as a double.
+    __ JumpIfSmi(exponent_tagged, &exponent_is_smi);
+    __ JumpIfNotHeapNumber(exponent_tagged, &call_runtime);
+    // exponent_tagged is a heap number, so load its double value.
+    __ Ldr(exponent_double,
+           FieldMemOperand(exponent_tagged, HeapNumber::kValueOffset));
+  } else if (exponent_type() == TAGGED) {
+    __ JumpIfSmi(exponent_tagged, &exponent_is_smi);
+    __ Ldr(exponent_double,
+           FieldMemOperand(exponent_tagged, HeapNumber::kValueOffset));
+  }
+
+  // Handle double (heap number) exponents.
+  if (exponent_type() != INTEGER) {
+    // Detect integer exponents stored as doubles and handle those in the
+    // integer fast-path.
+    __ TryRepresentDoubleAsInt64(exponent_integer, exponent_double,
+                                 scratch0_double, &exponent_is_integer);
+
+    if (exponent_type() == ON_STACK) {
+      FPRegister  half_double = d3;
+      FPRegister  minus_half_double = d4;
+      // Detect square root case. Crankshaft detects constant +/-0.5 at compile
+      // time and uses DoMathPowHalf instead. We then skip this check for
+      // non-constant cases of +/-0.5 as these hardly occur.
+
+      __ Fmov(minus_half_double, -0.5);
+      __ Fmov(half_double, 0.5);
+      __ Fcmp(minus_half_double, exponent_double);
+      __ Fccmp(half_double, exponent_double, NZFlag, ne);
+      // Condition flags at this point:
+      //    0.5;  nZCv    // Identified by eq && pl
+      //   -0.5:  NZcv    // Identified by eq && mi
+      //  other:  ?z??    // Identified by ne
+      __ B(ne, &call_runtime);
+
+      // The exponent is 0.5 or -0.5.
+
+      // Given that exponent is known to be either 0.5 or -0.5, the following
+      // special cases could apply (according to ECMA-262 15.8.2.13):
+      //
+      //  base.isNaN():                   The result is NaN.
+      //  (base == +INFINITY) || (base == -INFINITY)
+      //    exponent == 0.5:              The result is +INFINITY.
+      //    exponent == -0.5:             The result is +0.
+      //  (base == +0) || (base == -0)
+      //    exponent == 0.5:              The result is +0.
+      //    exponent == -0.5:             The result is +INFINITY.
+      //  (base < 0) && base.isFinite():  The result is NaN.
+      //
+      // Fsqrt (and Fdiv for the -0.5 case) can handle all of those except
+      // where base is -INFINITY or -0.
+
+      // Add +0 to base. This has no effect other than turning -0 into +0.
+      __ Fadd(base_double, base_double, fp_zero);
+      // The operation -0+0 results in +0 in all cases except where the
+      // FPCR rounding mode is 'round towards minus infinity' (RM). The
+      // ARM64 simulator does not currently simulate FPCR (where the rounding
+      // mode is set), so test the operation with some debug code.
+      if (masm->emit_debug_code()) {
+        UseScratchRegisterScope temps(masm);
+        Register temp = temps.AcquireX();
+        __ Fneg(scratch0_double, fp_zero);
+        // Verify that we correctly generated +0.0 and -0.0.
+        //  bits(+0.0) = 0x0000000000000000
+        //  bits(-0.0) = 0x8000000000000000
+        __ Fmov(temp, fp_zero);
+        __ CheckRegisterIsClear(temp, kCouldNotGenerateZero);
+        __ Fmov(temp, scratch0_double);
+        __ Eor(temp, temp, kDSignMask);
+        __ CheckRegisterIsClear(temp, kCouldNotGenerateNegativeZero);
+        // Check that -0.0 + 0.0 == +0.0.
+        __ Fadd(scratch0_double, scratch0_double, fp_zero);
+        __ Fmov(temp, scratch0_double);
+        __ CheckRegisterIsClear(temp, kExpectedPositiveZero);
+      }
+
+      // If base is -INFINITY, make it +INFINITY.
+      //  * Calculate base - base: All infinities will become NaNs since both
+      //    -INFINITY+INFINITY and +INFINITY-INFINITY are NaN in ARM64.
+      //  * If the result is NaN, calculate abs(base).
+      __ Fsub(scratch0_double, base_double, base_double);
+      __ Fcmp(scratch0_double, 0.0);
+      __ Fabs(scratch1_double, base_double);
+      __ Fcsel(base_double, scratch1_double, base_double, vs);
+
+      // Calculate the square root of base.
+      __ Fsqrt(result_double, base_double);
+      __ Fcmp(exponent_double, 0.0);
+      __ B(ge, &done);  // Finish now for exponents of 0.5.
+      // Find the inverse for exponents of -0.5.
+      __ Fmov(scratch0_double, 1.0);
+      __ Fdiv(result_double, scratch0_double, result_double);
+      __ B(&done);
+    }
+
+    {
+      AllowExternalCallThatCantCauseGC scope(masm);
+      __ Mov(saved_lr, lr);
+      __ CallCFunction(
+          ExternalReference::power_double_double_function(isolate()),
+          0, 2);
+      __ Mov(lr, saved_lr);
+      __ B(&done);
+    }
+
+    // Handle SMI exponents.
+    __ Bind(&exponent_is_smi);
+    //  x10   base_tagged       The tagged base (input).
+    //  x11   exponent_tagged   The tagged exponent (input).
+    //  d1    base_double       The base as a double.
+    __ SmiUntag(exponent_integer, exponent_tagged);
+  }
+
+  __ Bind(&exponent_is_integer);
+  //  x10   base_tagged       The tagged base (input).
+  //  x11   exponent_tagged   The tagged exponent (input).
+  //  x12   exponent_integer  The exponent as an integer.
+  //  d1    base_double       The base as a double.
+
+  // Find abs(exponent). For negative exponents, we can find the inverse later.
+  Register exponent_abs = x13;
+  __ Cmp(exponent_integer, 0);
+  __ Cneg(exponent_abs, exponent_integer, mi);
+  //  x13   exponent_abs      The value of abs(exponent_integer).
+
+  // Repeatedly multiply to calculate the power.
+  //  result = 1.0;
+  //  For each bit n (exponent_integer{n}) {
+  //    if (exponent_integer{n}) {
+  //      result *= base;
+  //    }
+  //    base *= base;
+  //    if (remaining bits in exponent_integer are all zero) {
+  //      break;
+  //    }
+  //  }
+  Label power_loop, power_loop_entry, power_loop_exit;
+  __ Fmov(scratch1_double, base_double);
+  __ Fmov(base_double_copy, base_double);
+  __ Fmov(result_double, 1.0);
+  __ B(&power_loop_entry);
+
+  __ Bind(&power_loop);
+  __ Fmul(scratch1_double, scratch1_double, scratch1_double);
+  __ Lsr(exponent_abs, exponent_abs, 1);
+  __ Cbz(exponent_abs, &power_loop_exit);
+
+  __ Bind(&power_loop_entry);
+  __ Tbz(exponent_abs, 0, &power_loop);
+  __ Fmul(result_double, result_double, scratch1_double);
+  __ B(&power_loop);
+
+  __ Bind(&power_loop_exit);
+
+  // If the exponent was positive, result_double holds the result.
+  __ Tbz(exponent_integer, kXSignBit, &done);
+
+  // The exponent was negative, so find the inverse.
+  __ Fmov(scratch0_double, 1.0);
+  __ Fdiv(result_double, scratch0_double, result_double);
+  // ECMA-262 only requires Math.pow to return an 'implementation-dependent
+  // approximation' of base^exponent. However, mjsunit/math-pow uses Math.pow
+  // to calculate the subnormal value 2^-1074. This method of calculating
+  // negative powers doesn't work because 2^1074 overflows to infinity. To
+  // catch this corner-case, we bail out if the result was 0. (This can only
+  // occur if the divisor is infinity or the base is zero.)
+  __ Fcmp(result_double, 0.0);
+  __ B(&done, ne);
+
+  if (exponent_type() == ON_STACK) {
+    // Bail out to runtime code.
+    __ Bind(&call_runtime);
+    // Put the arguments back on the stack.
+    __ Push(base_tagged, exponent_tagged);
+    __ TailCallRuntime(Runtime::kMathPowRT, 2, 1);
+
+    // Return.
+    __ Bind(&done);
+    __ AllocateHeapNumber(result_tagged, &call_runtime, scratch0, scratch1,
+                          result_double);
+    DCHECK(result_tagged.is(x0));
+    __ IncrementCounter(
+        isolate()->counters()->math_pow(), 1, scratch0, scratch1);
+    __ Ret();
+  } else {
+    AllowExternalCallThatCantCauseGC scope(masm);
+    __ Mov(saved_lr, lr);
+    __ Fmov(base_double, base_double_copy);
+    __ Scvtf(exponent_double, exponent_integer);
+    __ CallCFunction(
+        ExternalReference::power_double_double_function(isolate()),
+        0, 2);
+    __ Mov(lr, saved_lr);
+    __ Bind(&done);
+    __ IncrementCounter(
+        isolate()->counters()->math_pow(), 1, scratch0, scratch1);
+    __ Ret();
+  }
+}
+
+
+void CodeStub::GenerateStubsAheadOfTime(Isolate* isolate) {
+  // It is important that the following stubs are generated in this order
+  // because pregenerated stubs can only call other pregenerated stubs.
+  // RecordWriteStub uses StoreBufferOverflowStub, which in turn uses
+  // CEntryStub.
+  CEntryStub::GenerateAheadOfTime(isolate);
+  StoreBufferOverflowStub::GenerateFixedRegStubsAheadOfTime(isolate);
+  StubFailureTrampolineStub::GenerateAheadOfTime(isolate);
+  ArrayConstructorStubBase::GenerateStubsAheadOfTime(isolate);
+  CreateAllocationSiteStub::GenerateAheadOfTime(isolate);
+  BinaryOpICStub::GenerateAheadOfTime(isolate);
+  StoreRegistersStateStub::GenerateAheadOfTime(isolate);
+  RestoreRegistersStateStub::GenerateAheadOfTime(isolate);
+  BinaryOpICWithAllocationSiteStub::GenerateAheadOfTime(isolate);
+}
+
+
+void StoreRegistersStateStub::GenerateAheadOfTime(Isolate* isolate) {
+  StoreRegistersStateStub stub(isolate);
+  stub.GetCode();
+}
+
+
+void RestoreRegistersStateStub::GenerateAheadOfTime(Isolate* isolate) {
+  RestoreRegistersStateStub stub(isolate);
+  stub.GetCode();
+}
+
+
+void CodeStub::GenerateFPStubs(Isolate* isolate) {
+  // Floating-point code doesn't get special handling in ARM64, so there's
+  // nothing to do here.
+  USE(isolate);
+}
+
+
+bool CEntryStub::NeedsImmovableCode() {
+  // CEntryStub stores the return address on the stack before calling into
+  // C++ code. In some cases, the VM accesses this address, but it is not used
+  // when the C++ code returns to the stub because LR holds the return address
+  // in AAPCS64. If the stub is moved (perhaps during a GC), we could end up
+  // returning to dead code.
+  // TODO(jbramley): Whilst this is the only analysis that makes sense, I can't
+  // find any comment to confirm this, and I don't hit any crashes whatever
+  // this function returns. The anaylsis should be properly confirmed.
+  return true;
+}
+
+
+void CEntryStub::GenerateAheadOfTime(Isolate* isolate) {
+  CEntryStub stub(isolate, 1, kDontSaveFPRegs);
+  stub.GetCode();
+  CEntryStub stub_fp(isolate, 1, kSaveFPRegs);
+  stub_fp.GetCode();
+}
+
+
+void CEntryStub::Generate(MacroAssembler* masm) {
+  // The Abort mechanism relies on CallRuntime, which in turn relies on
+  // CEntryStub, so until this stub has been generated, we have to use a
+  // fall-back Abort mechanism.
+  //
+  // Note that this stub must be generated before any use of Abort.
+  MacroAssembler::NoUseRealAbortsScope no_use_real_aborts(masm);
+
+  ASM_LOCATION("CEntryStub::Generate entry");
+  ProfileEntryHookStub::MaybeCallEntryHook(masm);
+
+  // Register parameters:
+  //    x0: argc (including receiver, untagged)
+  //    x1: target
+  //
+  // The stack on entry holds the arguments and the receiver, with the receiver
+  // at the highest address:
+  //
+  //    jssp]argc-1]: receiver
+  //    jssp[argc-2]: arg[argc-2]
+  //    ...           ...
+  //    jssp[1]:      arg[1]
+  //    jssp[0]:      arg[0]
+  //
+  // The arguments are in reverse order, so that arg[argc-2] is actually the
+  // first argument to the target function and arg[0] is the last.
+  DCHECK(jssp.Is(__ StackPointer()));
+  const Register& argc_input = x0;
+  const Register& target_input = x1;
+
+  // Calculate argv, argc and the target address, and store them in
+  // callee-saved registers so we can retry the call without having to reload
+  // these arguments.
+  // TODO(jbramley): If the first call attempt succeeds in the common case (as
+  // it should), then we might be better off putting these parameters directly
+  // into their argument registers, rather than using callee-saved registers and
+  // preserving them on the stack.
+  const Register& argv = x21;
+  const Register& argc = x22;
+  const Register& target = x23;
+
+  // Derive argv from the stack pointer so that it points to the first argument
+  // (arg[argc-2]), or just below the receiver in case there are no arguments.
+  //  - Adjust for the arg[] array.
+  Register temp_argv = x11;
+  __ Add(temp_argv, jssp, Operand(x0, LSL, kPointerSizeLog2));
+  //  - Adjust for the receiver.
+  __ Sub(temp_argv, temp_argv, 1 * kPointerSize);
+
+  // Enter the exit frame. Reserve three slots to preserve x21-x23 callee-saved
+  // registers.
+  FrameScope scope(masm, StackFrame::MANUAL);
+  __ EnterExitFrame(save_doubles(), x10, 3);
+  DCHECK(csp.Is(__ StackPointer()));
+
+  // Poke callee-saved registers into reserved space.
+  __ Poke(argv, 1 * kPointerSize);
+  __ Poke(argc, 2 * kPointerSize);
+  __ Poke(target, 3 * kPointerSize);
+
+  // We normally only keep tagged values in callee-saved registers, as they
+  // could be pushed onto the stack by called stubs and functions, and on the
+  // stack they can confuse the GC. However, we're only calling C functions
+  // which can push arbitrary data onto the stack anyway, and so the GC won't
+  // examine that part of the stack.
+  __ Mov(argc, argc_input);
+  __ Mov(target, target_input);
+  __ Mov(argv, temp_argv);
+
+  // x21 : argv
+  // x22 : argc
+  // x23 : call target
+  //
+  // The stack (on entry) holds the arguments and the receiver, with the
+  // receiver at the highest address:
+  //
+  //         argv[8]:     receiver
+  // argv -> argv[0]:     arg[argc-2]
+  //         ...          ...
+  //         argv[...]:   arg[1]
+  //         argv[...]:   arg[0]
+  //
+  // Immediately below (after) this is the exit frame, as constructed by
+  // EnterExitFrame:
+  //         fp[8]:    CallerPC (lr)
+  //   fp -> fp[0]:    CallerFP (old fp)
+  //         fp[-8]:   Space reserved for SPOffset.
+  //         fp[-16]:  CodeObject()
+  //         csp[...]: Saved doubles, if saved_doubles is true.
+  //         csp[32]:  Alignment padding, if necessary.
+  //         csp[24]:  Preserved x23 (used for target).
+  //         csp[16]:  Preserved x22 (used for argc).
+  //         csp[8]:   Preserved x21 (used for argv).
+  //  csp -> csp[0]:   Space reserved for the return address.
+  //
+  // After a successful call, the exit frame, preserved registers (x21-x23) and
+  // the arguments (including the receiver) are dropped or popped as
+  // appropriate. The stub then returns.
+  //
+  // After an unsuccessful call, the exit frame and suchlike are left
+  // untouched, and the stub either throws an exception by jumping to one of
+  // the exception_returned label.
+
+  DCHECK(csp.Is(__ StackPointer()));
+
+  // Prepare AAPCS64 arguments to pass to the builtin.
+  __ Mov(x0, argc);
+  __ Mov(x1, argv);
+  __ Mov(x2, ExternalReference::isolate_address(isolate()));
+
+  Label return_location;
+  __ Adr(x12, &return_location);
+  __ Poke(x12, 0);
+
+  if (__ emit_debug_code()) {
+    // Verify that the slot below fp[kSPOffset]-8 points to the return location
+    // (currently in x12).
+    UseScratchRegisterScope temps(masm);
+    Register temp = temps.AcquireX();
+    __ Ldr(temp, MemOperand(fp, ExitFrameConstants::kSPOffset));
+    __ Ldr(temp, MemOperand(temp, -static_cast<int64_t>(kXRegSize)));
+    __ Cmp(temp, x12);
+    __ Check(eq, kReturnAddressNotFoundInFrame);
+  }
+
+  // Call the builtin.
+  __ Blr(target);
+  __ Bind(&return_location);
+
+  //  x0    result      The return code from the call.
+  //  x21   argv
+  //  x22   argc
+  //  x23   target
+  const Register& result = x0;
+
+  // Check result for exception sentinel.
+  Label exception_returned;
+  __ CompareRoot(result, Heap::kExceptionRootIndex);
+  __ B(eq, &exception_returned);
+
+  // The call succeeded, so unwind the stack and return.
+
+  // Restore callee-saved registers x21-x23.
+  __ Mov(x11, argc);
+
+  __ Peek(argv, 1 * kPointerSize);
+  __ Peek(argc, 2 * kPointerSize);
+  __ Peek(target, 3 * kPointerSize);
+
+  __ LeaveExitFrame(save_doubles(), x10, true);
+  DCHECK(jssp.Is(__ StackPointer()));
+  // Pop or drop the remaining stack slots and return from the stub.
+  //         jssp[24]:    Arguments array (of size argc), including receiver.
+  //         jssp[16]:    Preserved x23 (used for target).
+  //         jssp[8]:     Preserved x22 (used for argc).
+  //         jssp[0]:     Preserved x21 (used for argv).
+  __ Drop(x11);
+  __ AssertFPCRState();
+  __ Ret();
+
+  // The stack pointer is still csp if we aren't returning, and the frame
+  // hasn't changed (except for the return address).
+  __ SetStackPointer(csp);
+
+  // Handling of exception.
+  __ Bind(&exception_returned);
+
+  // Retrieve the pending exception.
+  ExternalReference pending_exception_address(
+      Isolate::kPendingExceptionAddress, isolate());
+  const Register& exception = result;
+  const Register& exception_address = x11;
+  __ Mov(exception_address, Operand(pending_exception_address));
+  __ Ldr(exception, MemOperand(exception_address));
+
+  // Clear the pending exception.
+  __ Mov(x10, Operand(isolate()->factory()->the_hole_value()));
+  __ Str(x10, MemOperand(exception_address));
+
+  //  x0    exception   The exception descriptor.
+  //  x21   argv
+  //  x22   argc
+  //  x23   target
+
+  // Special handling of termination exceptions, which are uncatchable by
+  // JavaScript code.
+  Label throw_termination_exception;
+  __ Cmp(exception, Operand(isolate()->factory()->termination_exception()));
+  __ B(eq, &throw_termination_exception);
+
+  // We didn't execute a return case, so the stack frame hasn't been updated
+  // (except for the return address slot). However, we don't need to initialize
+  // jssp because the throw method will immediately overwrite it when it
+  // unwinds the stack.
+  __ SetStackPointer(jssp);
+
+  ASM_LOCATION("Throw normal");
+  __ Mov(argv, 0);
+  __ Mov(argc, 0);
+  __ Mov(target, 0);
+  __ Throw(x0, x10, x11, x12, x13);
+
+  __ Bind(&throw_termination_exception);
+  ASM_LOCATION("Throw termination");
+  __ Mov(argv, 0);
+  __ Mov(argc, 0);
+  __ Mov(target, 0);
+  __ ThrowUncatchable(x0, x10, x11, x12, x13);
+}
+
+
+// This is the entry point from C++. 5 arguments are provided in x0-x4.
+// See use of the CALL_GENERATED_CODE macro for example in src/execution.cc.
+// Input:
+//   x0: code entry.
+//   x1: function.
+//   x2: receiver.
+//   x3: argc.
+//   x4: argv.
+// Output:
+//   x0: result.
+void JSEntryStub::Generate(MacroAssembler* masm) {
+  DCHECK(jssp.Is(__ StackPointer()));
+  Register code_entry = x0;
+
+  // Enable instruction instrumentation. This only works on the simulator, and
+  // will have no effect on the model or real hardware.
+  __ EnableInstrumentation();
+
+  Label invoke, handler_entry, exit;
+
+  // Push callee-saved registers and synchronize the system stack pointer (csp)
+  // and the JavaScript stack pointer (jssp).
+  //
+  // We must not write to jssp until after the PushCalleeSavedRegisters()
+  // call, since jssp is itself a callee-saved register.
+  __ SetStackPointer(csp);
+  __ PushCalleeSavedRegisters();
+  __ Mov(jssp, csp);
+  __ SetStackPointer(jssp);
+
+  // Configure the FPCR. We don't restore it, so this is technically not allowed
+  // according to AAPCS64. However, we only set default-NaN mode and this will
+  // be harmless for most C code. Also, it works for ARM.
+  __ ConfigureFPCR();
+
+  ProfileEntryHookStub::MaybeCallEntryHook(masm);
+
+  // Set up the reserved register for 0.0.
+  __ Fmov(fp_zero, 0.0);
+
+  // Build an entry frame (see layout below).
+  int marker = type();
+  int64_t bad_frame_pointer = -1L;  // Bad frame pointer to fail if it is used.
+  __ Mov(x13, bad_frame_pointer);
+  __ Mov(x12, Smi::FromInt(marker));
+  __ Mov(x11, ExternalReference(Isolate::kCEntryFPAddress, isolate()));
+  __ Ldr(x10, MemOperand(x11));
+
+  __ Push(x13, xzr, x12, x10);
+  // Set up fp.
+  __ Sub(fp, jssp, EntryFrameConstants::kCallerFPOffset);
+
+  // Push the JS entry frame marker. Also set js_entry_sp if this is the
+  // outermost JS call.
+  Label non_outermost_js, done;
+  ExternalReference js_entry_sp(Isolate::kJSEntrySPAddress, isolate());
+  __ Mov(x10, ExternalReference(js_entry_sp));
+  __ Ldr(x11, MemOperand(x10));
+  __ Cbnz(x11, &non_outermost_js);
+  __ Str(fp, MemOperand(x10));
+  __ Mov(x12, Smi::FromInt(StackFrame::OUTERMOST_JSENTRY_FRAME));
+  __ Push(x12);
+  __ B(&done);
+  __ Bind(&non_outermost_js);
+  // We spare one instruction by pushing xzr since the marker is 0.
+  DCHECK(Smi::FromInt(StackFrame::INNER_JSENTRY_FRAME) == NULL);
+  __ Push(xzr);
+  __ Bind(&done);
+
+  // The frame set up looks like this:
+  // jssp[0] : JS entry frame marker.
+  // jssp[1] : C entry FP.
+  // jssp[2] : stack frame marker.
+  // jssp[3] : stack frmae marker.
+  // jssp[4] : bad frame pointer 0xfff...ff   <- fp points here.
+
+
+  // Jump to a faked try block that does the invoke, with a faked catch
+  // block that sets the pending exception.
+  __ B(&invoke);
+
+  // Prevent the constant pool from being emitted between the record of the
+  // handler_entry position and the first instruction of the sequence here.
+  // There is no risk because Assembler::Emit() emits the instruction before
+  // checking for constant pool emission, but we do not want to depend on
+  // that.
+  {
+    Assembler::BlockPoolsScope block_pools(masm);
+    __ bind(&handler_entry);
+    handler_offset_ = handler_entry.pos();
+    // Caught exception: Store result (exception) in the pending exception
+    // field in the JSEnv and return a failure sentinel. Coming in here the
+    // fp will be invalid because the PushTryHandler below sets it to 0 to
+    // signal the existence of the JSEntry frame.
+    __ Mov(x10, Operand(ExternalReference(Isolate::kPendingExceptionAddress,
+                                          isolate())));
+  }
+  __ Str(code_entry, MemOperand(x10));
+  __ LoadRoot(x0, Heap::kExceptionRootIndex);
+  __ B(&exit);
+
+  // Invoke: Link this frame into the handler chain.  There's only one
+  // handler block in this code object, so its index is 0.
+  __ Bind(&invoke);
+  __ PushTryHandler(StackHandler::JS_ENTRY, 0);
+  // If an exception not caught by another handler occurs, this handler
+  // returns control to the code after the B(&invoke) above, which
+  // restores all callee-saved registers (including cp and fp) to their
+  // saved values before returning a failure to C.
+
+  // Clear any pending exceptions.
+  __ Mov(x10, Operand(isolate()->factory()->the_hole_value()));
+  __ Mov(x11, Operand(ExternalReference(Isolate::kPendingExceptionAddress,
+                                        isolate())));
+  __ Str(x10, MemOperand(x11));
+
+  // Invoke the function by calling through the JS entry trampoline builtin.
+  // Notice that we cannot store a reference to the trampoline code directly in
+  // this stub, because runtime stubs are not traversed when doing GC.
+
+  // Expected registers by Builtins::JSEntryTrampoline
+  // x0: code entry.
+  // x1: function.
+  // x2: receiver.
+  // x3: argc.
+  // x4: argv.
+  ExternalReference entry(type() == StackFrame::ENTRY_CONSTRUCT
+                              ? Builtins::kJSConstructEntryTrampoline
+                              : Builtins::kJSEntryTrampoline,
+                          isolate());
+  __ Mov(x10, entry);
+
+  // Call the JSEntryTrampoline.
+  __ Ldr(x11, MemOperand(x10));  // Dereference the address.
+  __ Add(x12, x11, Code::kHeaderSize - kHeapObjectTag);
+  __ Blr(x12);
+
+  // Unlink this frame from the handler chain.
+  __ PopTryHandler();
+
+
+  __ Bind(&exit);
+  // x0 holds the result.
+  // The stack pointer points to the top of the entry frame pushed on entry from
+  // C++ (at the beginning of this stub):
+  // jssp[0] : JS entry frame marker.
+  // jssp[1] : C entry FP.
+  // jssp[2] : stack frame marker.
+  // jssp[3] : stack frmae marker.
+  // jssp[4] : bad frame pointer 0xfff...ff   <- fp points here.
+
+  // Check if the current stack frame is marked as the outermost JS frame.
+  Label non_outermost_js_2;
+  __ Pop(x10);
+  __ Cmp(x10, Smi::FromInt(StackFrame::OUTERMOST_JSENTRY_FRAME));
+  __ B(ne, &non_outermost_js_2);
+  __ Mov(x11, ExternalReference(js_entry_sp));
+  __ Str(xzr, MemOperand(x11));
+  __ Bind(&non_outermost_js_2);
+
+  // Restore the top frame descriptors from the stack.
+  __ Pop(x10);
+  __ Mov(x11, ExternalReference(Isolate::kCEntryFPAddress, isolate()));
+  __ Str(x10, MemOperand(x11));
+
+  // Reset the stack to the callee saved registers.
+  __ Drop(-EntryFrameConstants::kCallerFPOffset, kByteSizeInBytes);
+  // Restore the callee-saved registers and return.
+  DCHECK(jssp.Is(__ StackPointer()));
+  __ Mov(csp, jssp);
+  __ SetStackPointer(csp);
+  __ PopCalleeSavedRegisters();
+  // After this point, we must not modify jssp because it is a callee-saved
+  // register which we have just restored.
+  __ Ret();
+}
+
+
+void FunctionPrototypeStub::Generate(MacroAssembler* masm) {
+  Label miss;
+  Register receiver = LoadDescriptor::ReceiverRegister();
+
+  NamedLoadHandlerCompiler::GenerateLoadFunctionPrototype(masm, receiver, x10,
+                                                          x11, &miss);
+
+  __ Bind(&miss);
+  PropertyAccessCompiler::TailCallBuiltin(
+      masm, PropertyAccessCompiler::MissBuiltin(Code::LOAD_IC));
+}
+
+
+void InstanceofStub::Generate(MacroAssembler* masm) {
+  // Stack on entry:
+  // jssp[0]: function.
+  // jssp[8]: object.
+  //
+  // Returns result in x0. Zero indicates instanceof, smi 1 indicates not
+  // instanceof.
+
+  Register result = x0;
+  Register function = right();
+  Register object = left();
+  Register scratch1 = x6;
+  Register scratch2 = x7;
+  Register res_true = x8;
+  Register res_false = x9;
+  // Only used if there was an inline map check site. (See
+  // LCodeGen::DoInstanceOfKnownGlobal().)
+  Register map_check_site = x4;
+  // Delta for the instructions generated between the inline map check and the
+  // instruction setting the result.
+  const int32_t kDeltaToLoadBoolResult = 4 * kInstructionSize;
+
+  Label not_js_object, slow;
+
+  if (!HasArgsInRegisters()) {
+    __ Pop(function, object);
+  }
+
+  if (ReturnTrueFalseObject()) {
+    __ LoadTrueFalseRoots(res_true, res_false);
+  } else {
+    // This is counter-intuitive, but correct.
+    __ Mov(res_true, Smi::FromInt(0));
+    __ Mov(res_false, Smi::FromInt(1));
+  }
+
+  // Check that the left hand side is a JS object and load its map as a side
+  // effect.
+  Register map = x12;
+  __ JumpIfSmi(object, &not_js_object);
+  __ IsObjectJSObjectType(object, map, scratch2, &not_js_object);
+
+  // If there is a call site cache, don't look in the global cache, but do the
+  // real lookup and update the call site cache.
+  if (!HasCallSiteInlineCheck() && !ReturnTrueFalseObject()) {
+    Label miss;
+    __ JumpIfNotRoot(function, Heap::kInstanceofCacheFunctionRootIndex, &miss);
+    __ JumpIfNotRoot(map, Heap::kInstanceofCacheMapRootIndex, &miss);
+    __ LoadRoot(result, Heap::kInstanceofCacheAnswerRootIndex);
+    __ Ret();
+    __ Bind(&miss);
+  }
+
+  // Get the prototype of the function.
+  Register prototype = x13;
+  __ TryGetFunctionPrototype(function, prototype, scratch2, &slow,
+                             MacroAssembler::kMissOnBoundFunction);
+
+  // Check that the function prototype is a JS object.
+  __ JumpIfSmi(prototype, &slow);
+  __ IsObjectJSObjectType(prototype, scratch1, scratch2, &slow);
+
+  // Update the global instanceof or call site inlined cache with the current
+  // map and function. The cached answer will be set when it is known below.
+  if (HasCallSiteInlineCheck()) {
+    // Patch the (relocated) inlined map check.
+    __ GetRelocatedValueLocation(map_check_site, scratch1);
+    // We have a cell, so need another level of dereferencing.
+    __ Ldr(scratch1, MemOperand(scratch1));
+    __ Str(map, FieldMemOperand(scratch1, Cell::kValueOffset));
+  } else {
+    __ StoreRoot(function, Heap::kInstanceofCacheFunctionRootIndex);
+    __ StoreRoot(map, Heap::kInstanceofCacheMapRootIndex);
+  }
+
+  Label return_true, return_result;
+  Register smi_value = scratch1;
+  {
+    // Loop through the prototype chain looking for the function prototype.
+    Register chain_map = x1;
+    Register chain_prototype = x14;
+    Register null_value = x15;
+    Label loop;
+    __ Ldr(chain_prototype, FieldMemOperand(map, Map::kPrototypeOffset));
+    __ LoadRoot(null_value, Heap::kNullValueRootIndex);
+    // Speculatively set a result.
+    __ Mov(result, res_false);
+    if (!HasCallSiteInlineCheck() && ReturnTrueFalseObject()) {
+      // Value to store in the cache cannot be an object.
+      __ Mov(smi_value, Smi::FromInt(1));
+    }
+
+    __ Bind(&loop);
+
+    // If the chain prototype is the object prototype, return true.
+    __ Cmp(chain_prototype, prototype);
+    __ B(eq, &return_true);
+
+    // If the chain prototype is null, we've reached the end of the chain, so
+    // return false.
+    __ Cmp(chain_prototype, null_value);
+    __ B(eq, &return_result);
+
+    // Otherwise, load the next prototype in the chain, and loop.
+    __ Ldr(chain_map, FieldMemOperand(chain_prototype, HeapObject::kMapOffset));
+    __ Ldr(chain_prototype, FieldMemOperand(chain_map, Map::kPrototypeOffset));
+    __ B(&loop);
+  }
+
+  // Return sequence when no arguments are on the stack.
+  // We cannot fall through to here.
+  __ Bind(&return_true);
+  __ Mov(result, res_true);
+  if (!HasCallSiteInlineCheck() && ReturnTrueFalseObject()) {
+    // Value to store in the cache cannot be an object.
+    __ Mov(smi_value, Smi::FromInt(0));
+  }
+  __ Bind(&return_result);
+  if (HasCallSiteInlineCheck()) {
+    DCHECK(ReturnTrueFalseObject());
+    __ Add(map_check_site, map_check_site, kDeltaToLoadBoolResult);
+    __ GetRelocatedValueLocation(map_check_site, scratch2);
+    __ Str(result, MemOperand(scratch2));
+  } else {
+    Register cached_value = ReturnTrueFalseObject() ? smi_value : result;
+    __ StoreRoot(cached_value, Heap::kInstanceofCacheAnswerRootIndex);
+  }
+  __ Ret();
+
+  Label object_not_null, object_not_null_or_smi;
+
+  __ Bind(&not_js_object);
+  Register object_type = x14;
+  //   x0   result        result return register (uninit)
+  //   x10  function      pointer to function
+  //   x11  object        pointer to object
+  //   x14  object_type   type of object (uninit)
+
+  // Before null, smi and string checks, check that the rhs is a function.
+  // For a non-function rhs, an exception must be thrown.
+  __ JumpIfSmi(function, &slow);
+  __ JumpIfNotObjectType(
+      function, scratch1, object_type, JS_FUNCTION_TYPE, &slow);
+
+  __ Mov(result, res_false);
+
+  // Null is not instance of anything.
+  __ Cmp(object_type, Operand(isolate()->factory()->null_value()));
+  __ B(ne, &object_not_null);
+  __ Ret();
+
+  __ Bind(&object_not_null);
+  // Smi values are not instances of anything.
+  __ JumpIfNotSmi(object, &object_not_null_or_smi);
+  __ Ret();
+
+  __ Bind(&object_not_null_or_smi);
+  // String values are not instances of anything.
+  __ IsObjectJSStringType(object, scratch2, &slow);
+  __ Ret();
+
+  // Slow-case. Tail call builtin.
+  __ Bind(&slow);
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    // Arguments have either been passed into registers or have been previously
+    // popped. We need to push them before calling builtin.
+    __ Push(object, function);
+    __ InvokeBuiltin(Builtins::INSTANCE_OF, CALL_FUNCTION);
+  }
+  if (ReturnTrueFalseObject()) {
+    // Reload true/false because they were clobbered in the builtin call.
+    __ LoadTrueFalseRoots(res_true, res_false);
+    __ Cmp(result, 0);
+    __ Csel(result, res_true, res_false, eq);
+  }
+  __ Ret();
+}
+
+
+void ArgumentsAccessStub::GenerateReadElement(MacroAssembler* masm) {
+  Register arg_count = ArgumentsAccessReadDescriptor::parameter_count();
+  Register key = ArgumentsAccessReadDescriptor::index();
+  DCHECK(arg_count.is(x0));
+  DCHECK(key.is(x1));
+
+  // The displacement is the offset of the last parameter (if any) relative
+  // to the frame pointer.
+  static const int kDisplacement =
+      StandardFrameConstants::kCallerSPOffset - kPointerSize;
+
+  // Check that the key is a smi.
+  Label slow;
+  __ JumpIfNotSmi(key, &slow);
+
+  // Check if the calling frame is an arguments adaptor frame.
+  Register local_fp = x11;
+  Register caller_fp = x11;
+  Register caller_ctx = x12;
+  Label skip_adaptor;
+  __ Ldr(caller_fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ Ldr(caller_ctx, MemOperand(caller_fp,
+                                StandardFrameConstants::kContextOffset));
+  __ Cmp(caller_ctx, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
+  __ Csel(local_fp, fp, caller_fp, ne);
+  __ B(ne, &skip_adaptor);
+
+  // Load the actual arguments limit found in the arguments adaptor frame.
+  __ Ldr(arg_count, MemOperand(caller_fp,
+                               ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ Bind(&skip_adaptor);
+
+  // Check index against formal parameters count limit. Use unsigned comparison
+  // to get negative check for free: branch if key < 0 or key >= arg_count.
+  __ Cmp(key, arg_count);
+  __ B(hs, &slow);
+
+  // Read the argument from the stack and return it.
+  __ Sub(x10, arg_count, key);
+  __ Add(x10, local_fp, Operand::UntagSmiAndScale(x10, kPointerSizeLog2));
+  __ Ldr(x0, MemOperand(x10, kDisplacement));
+  __ Ret();
+
+  // Slow case: handle non-smi or out-of-bounds access to arguments by calling
+  // the runtime system.
+  __ Bind(&slow);
+  __ Push(key);
+  __ TailCallRuntime(Runtime::kGetArgumentsProperty, 1, 1);
+}
+
+
+void ArgumentsAccessStub::GenerateNewSloppySlow(MacroAssembler* masm) {
+  // Stack layout on entry.
+  //  jssp[0]:  number of parameters (tagged)
+  //  jssp[8]:  address of receiver argument
+  //  jssp[16]: function
+
+  // Check if the calling frame is an arguments adaptor frame.
+  Label runtime;
+  Register caller_fp = x10;
+  __ Ldr(caller_fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  // Load and untag the context.
+  __ Ldr(w11, UntagSmiMemOperand(caller_fp,
+                                 StandardFrameConstants::kContextOffset));
+  __ Cmp(w11, StackFrame::ARGUMENTS_ADAPTOR);
+  __ B(ne, &runtime);
+
+  // Patch the arguments.length and parameters pointer in the current frame.
+  __ Ldr(x11, MemOperand(caller_fp,
+                         ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ Poke(x11, 0 * kXRegSize);
+  __ Add(x10, caller_fp, Operand::UntagSmiAndScale(x11, kPointerSizeLog2));
+  __ Add(x10, x10, StandardFrameConstants::kCallerSPOffset);
+  __ Poke(x10, 1 * kXRegSize);
+
+  __ Bind(&runtime);
+  __ TailCallRuntime(Runtime::kNewSloppyArguments, 3, 1);
+}
+
+
+void ArgumentsAccessStub::GenerateNewSloppyFast(MacroAssembler* masm) {
+  // Stack layout on entry.
+  //  jssp[0]:  number of parameters (tagged)
+  //  jssp[8]:  address of receiver argument
+  //  jssp[16]: function
+  //
+  // Returns pointer to result object in x0.
+
+  // Note: arg_count_smi is an alias of param_count_smi.
+  Register arg_count_smi = x3;
+  Register param_count_smi = x3;
+  Register param_count = x7;
+  Register recv_arg = x14;
+  Register function = x4;
+  __ Pop(param_count_smi, recv_arg, function);
+  __ SmiUntag(param_count, param_count_smi);
+
+  // Check if the calling frame is an arguments adaptor frame.
+  Register caller_fp = x11;
+  Register caller_ctx = x12;
+  Label runtime;
+  Label adaptor_frame, try_allocate;
+  __ Ldr(caller_fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ Ldr(caller_ctx, MemOperand(caller_fp,
+                                StandardFrameConstants::kContextOffset));
+  __ Cmp(caller_ctx, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
+  __ B(eq, &adaptor_frame);
+
+  // No adaptor, parameter count = argument count.
+
+  //   x1   mapped_params number of mapped params, min(params, args) (uninit)
+  //   x2   arg_count     number of function arguments (uninit)
+  //   x3   arg_count_smi number of function arguments (smi)
+  //   x4   function      function pointer
+  //   x7   param_count   number of function parameters
+  //   x11  caller_fp     caller's frame pointer
+  //   x14  recv_arg      pointer to receiver arguments
+
+  Register arg_count = x2;
+  __ Mov(arg_count, param_count);
+  __ B(&try_allocate);
+
+  // We have an adaptor frame. Patch the parameters pointer.
+  __ Bind(&adaptor_frame);
+  __ Ldr(arg_count_smi,
+         MemOperand(caller_fp,
+                    ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ SmiUntag(arg_count, arg_count_smi);
+  __ Add(x10, caller_fp, Operand(arg_count, LSL, kPointerSizeLog2));
+  __ Add(recv_arg, x10, StandardFrameConstants::kCallerSPOffset);
+
+  // Compute the mapped parameter count = min(param_count, arg_count)
+  Register mapped_params = x1;
+  __ Cmp(param_count, arg_count);
+  __ Csel(mapped_params, param_count, arg_count, lt);
+
+  __ Bind(&try_allocate);
+
+  //   x0   alloc_obj     pointer to allocated objects: param map, backing
+  //                      store, arguments (uninit)
+  //   x1   mapped_params number of mapped parameters, min(params, args)
+  //   x2   arg_count     number of function arguments
+  //   x3   arg_count_smi number of function arguments (smi)
+  //   x4   function      function pointer
+  //   x7   param_count   number of function parameters
+  //   x10  size          size of objects to allocate (uninit)
+  //   x14  recv_arg      pointer to receiver arguments
+
+  // Compute the size of backing store, parameter map, and arguments object.
+  // 1. Parameter map, has two extra words containing context and backing
+  // store.
+  const int kParameterMapHeaderSize =
+      FixedArray::kHeaderSize + 2 * kPointerSize;
+
+  // Calculate the parameter map size, assuming it exists.
+  Register size = x10;
+  __ Mov(size, Operand(mapped_params, LSL, kPointerSizeLog2));
+  __ Add(size, size, kParameterMapHeaderSize);
+
+  // If there are no mapped parameters, set the running size total to zero.
+  // Otherwise, use the parameter map size calculated earlier.
+  __ Cmp(mapped_params, 0);
+  __ CzeroX(size, eq);
+
+  // 2. Add the size of the backing store and arguments object.
+  __ Add(size, size, Operand(arg_count, LSL, kPointerSizeLog2));
+  __ Add(size, size,
+         FixedArray::kHeaderSize + Heap::kSloppyArgumentsObjectSize);
+
+  // Do the allocation of all three objects in one go. Assign this to x0, as it
+  // will be returned to the caller.
+  Register alloc_obj = x0;
+  __ Allocate(size, alloc_obj, x11, x12, &runtime, TAG_OBJECT);
+
+  // Get the arguments boilerplate from the current (global) context.
+
+  //   x0   alloc_obj       pointer to allocated objects (param map, backing
+  //                        store, arguments)
+  //   x1   mapped_params   number of mapped parameters, min(params, args)
+  //   x2   arg_count       number of function arguments
+  //   x3   arg_count_smi   number of function arguments (smi)
+  //   x4   function        function pointer
+  //   x7   param_count     number of function parameters
+  //   x11  sloppy_args_map offset to args (or aliased args) map (uninit)
+  //   x14  recv_arg        pointer to receiver arguments
+
+  Register global_object = x10;
+  Register global_ctx = x10;
+  Register sloppy_args_map = x11;
+  Register aliased_args_map = x10;
+  __ Ldr(global_object, GlobalObjectMemOperand());
+  __ Ldr(global_ctx, FieldMemOperand(global_object,
+                                     GlobalObject::kNativeContextOffset));
+
+  __ Ldr(sloppy_args_map,
+         ContextMemOperand(global_ctx, Context::SLOPPY_ARGUMENTS_MAP_INDEX));
+  __ Ldr(aliased_args_map,
+         ContextMemOperand(global_ctx, Context::ALIASED_ARGUMENTS_MAP_INDEX));
+  __ Cmp(mapped_params, 0);
+  __ CmovX(sloppy_args_map, aliased_args_map, ne);
+
+  // Copy the JS object part.
+  __ Str(sloppy_args_map, FieldMemOperand(alloc_obj, JSObject::kMapOffset));
+  __ LoadRoot(x10, Heap::kEmptyFixedArrayRootIndex);
+  __ Str(x10, FieldMemOperand(alloc_obj, JSObject::kPropertiesOffset));
+  __ Str(x10, FieldMemOperand(alloc_obj, JSObject::kElementsOffset));
+
+  // Set up the callee in-object property.
+  STATIC_ASSERT(Heap::kArgumentsCalleeIndex == 1);
+  const int kCalleeOffset = JSObject::kHeaderSize +
+                            Heap::kArgumentsCalleeIndex * kPointerSize;
+  __ AssertNotSmi(function);
+  __ Str(function, FieldMemOperand(alloc_obj, kCalleeOffset));
+
+  // Use the length and set that as an in-object property.
+  STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
+  const int kLengthOffset = JSObject::kHeaderSize +
+                            Heap::kArgumentsLengthIndex * kPointerSize;
+  __ Str(arg_count_smi, FieldMemOperand(alloc_obj, kLengthOffset));
+
+  // Set up the elements pointer in the allocated arguments object.
+  // If we allocated a parameter map, "elements" will point there, otherwise
+  // it will point to the backing store.
+
+  //   x0   alloc_obj     pointer to allocated objects (param map, backing
+  //                      store, arguments)
+  //   x1   mapped_params number of mapped parameters, min(params, args)
+  //   x2   arg_count     number of function arguments
+  //   x3   arg_count_smi number of function arguments (smi)
+  //   x4   function      function pointer
+  //   x5   elements      pointer to parameter map or backing store (uninit)
+  //   x6   backing_store pointer to backing store (uninit)
+  //   x7   param_count   number of function parameters
+  //   x14  recv_arg      pointer to receiver arguments
+
+  Register elements = x5;
+  __ Add(elements, alloc_obj, Heap::kSloppyArgumentsObjectSize);
+  __ Str(elements, FieldMemOperand(alloc_obj, JSObject::kElementsOffset));
+
+  // Initialize parameter map. If there are no mapped arguments, we're done.
+  Label skip_parameter_map;
+  __ Cmp(mapped_params, 0);
+  // Set up backing store address, because it is needed later for filling in
+  // the unmapped arguments.
+  Register backing_store = x6;
+  __ CmovX(backing_store, elements, eq);
+  __ B(eq, &skip_parameter_map);
+
+  __ LoadRoot(x10, Heap::kSloppyArgumentsElementsMapRootIndex);
+  __ Str(x10, FieldMemOperand(elements, FixedArray::kMapOffset));
+  __ Add(x10, mapped_params, 2);
+  __ SmiTag(x10);
+  __ Str(x10, FieldMemOperand(elements, FixedArray::kLengthOffset));
+  __ Str(cp, FieldMemOperand(elements,
+                             FixedArray::kHeaderSize + 0 * kPointerSize));
+  __ Add(x10, elements, Operand(mapped_params, LSL, kPointerSizeLog2));
+  __ Add(x10, x10, kParameterMapHeaderSize);
+  __ Str(x10, FieldMemOperand(elements,
+                              FixedArray::kHeaderSize + 1 * kPointerSize));
+
+  // Copy the parameter slots and the holes in the arguments.
+  // We need to fill in mapped_parameter_count slots. Then index the context,
+  // where parameters are stored in reverse order, at:
+  //
+  //   MIN_CONTEXT_SLOTS .. MIN_CONTEXT_SLOTS + parameter_count - 1
+  //
+  // The mapped parameter thus needs to get indices:
+  //
+  //   MIN_CONTEXT_SLOTS + parameter_count - 1 ..
+  //     MIN_CONTEXT_SLOTS + parameter_count - mapped_parameter_count
+  //
+  // We loop from right to left.
+
+  //   x0   alloc_obj     pointer to allocated objects (param map, backing
+  //                      store, arguments)
+  //   x1   mapped_params number of mapped parameters, min(params, args)
+  //   x2   arg_count     number of function arguments
+  //   x3   arg_count_smi number of function arguments (smi)
+  //   x4   function      function pointer
+  //   x5   elements      pointer to parameter map or backing store (uninit)
+  //   x6   backing_store pointer to backing store (uninit)
+  //   x7   param_count   number of function parameters
+  //   x11  loop_count    parameter loop counter (uninit)
+  //   x12  index         parameter index (smi, uninit)
+  //   x13  the_hole      hole value (uninit)
+  //   x14  recv_arg      pointer to receiver arguments
+
+  Register loop_count = x11;
+  Register index = x12;
+  Register the_hole = x13;
+  Label parameters_loop, parameters_test;
+  __ Mov(loop_count, mapped_params);
+  __ Add(index, param_count, static_cast<int>(Context::MIN_CONTEXT_SLOTS));
+  __ Sub(index, index, mapped_params);
+  __ SmiTag(index);
+  __ LoadRoot(the_hole, Heap::kTheHoleValueRootIndex);
+  __ Add(backing_store, elements, Operand(loop_count, LSL, kPointerSizeLog2));
+  __ Add(backing_store, backing_store, kParameterMapHeaderSize);
+
+  __ B(&parameters_test);
+
+  __ Bind(&parameters_loop);
+  __ Sub(loop_count, loop_count, 1);
+  __ Mov(x10, Operand(loop_count, LSL, kPointerSizeLog2));
+  __ Add(x10, x10, kParameterMapHeaderSize - kHeapObjectTag);
+  __ Str(index, MemOperand(elements, x10));
+  __ Sub(x10, x10, kParameterMapHeaderSize - FixedArray::kHeaderSize);
+  __ Str(the_hole, MemOperand(backing_store, x10));
+  __ Add(index, index, Smi::FromInt(1));
+  __ Bind(&parameters_test);
+  __ Cbnz(loop_count, &parameters_loop);
+
+  __ Bind(&skip_parameter_map);
+  // Copy arguments header and remaining slots (if there are any.)
+  __ LoadRoot(x10, Heap::kFixedArrayMapRootIndex);
+  __ Str(x10, FieldMemOperand(backing_store, FixedArray::kMapOffset));
+  __ Str(arg_count_smi, FieldMemOperand(backing_store,
+                                        FixedArray::kLengthOffset));
+
+  //   x0   alloc_obj     pointer to allocated objects (param map, backing
+  //                      store, arguments)
+  //   x1   mapped_params number of mapped parameters, min(params, args)
+  //   x2   arg_count     number of function arguments
+  //   x4   function      function pointer
+  //   x3   arg_count_smi number of function arguments (smi)
+  //   x6   backing_store pointer to backing store (uninit)
+  //   x14  recv_arg      pointer to receiver arguments
+
+  Label arguments_loop, arguments_test;
+  __ Mov(x10, mapped_params);
+  __ Sub(recv_arg, recv_arg, Operand(x10, LSL, kPointerSizeLog2));
+  __ B(&arguments_test);
+
+  __ Bind(&arguments_loop);
+  __ Sub(recv_arg, recv_arg, kPointerSize);
+  __ Ldr(x11, MemOperand(recv_arg));
+  __ Add(x12, backing_store, Operand(x10, LSL, kPointerSizeLog2));
+  __ Str(x11, FieldMemOperand(x12, FixedArray::kHeaderSize));
+  __ Add(x10, x10, 1);
+
+  __ Bind(&arguments_test);
+  __ Cmp(x10, arg_count);
+  __ B(lt, &arguments_loop);
+
+  __ Ret();
+
+  // Do the runtime call to allocate the arguments object.
+  __ Bind(&runtime);
+  __ Push(function, recv_arg, arg_count_smi);
+  __ TailCallRuntime(Runtime::kNewSloppyArguments, 3, 1);
+}
+
+
+void LoadIndexedInterceptorStub::Generate(MacroAssembler* masm) {
+  // Return address is in lr.
+  Label slow;
+
+  Register receiver = LoadDescriptor::ReceiverRegister();
+  Register key = LoadDescriptor::NameRegister();
+
+  // Check that the key is an array index, that is Uint32.
+  __ TestAndBranchIfAnySet(key, kSmiTagMask | kSmiSignMask, &slow);
+
+  // Everything is fine, call runtime.
+  __ Push(receiver, key);
+  __ TailCallExternalReference(
+      ExternalReference(IC_Utility(IC::kLoadElementWithInterceptor),
+                        masm->isolate()),
+      2, 1);
+
+  __ Bind(&slow);
+  PropertyAccessCompiler::TailCallBuiltin(
+      masm, PropertyAccessCompiler::MissBuiltin(Code::KEYED_LOAD_IC));
+}
+
+
+void ArgumentsAccessStub::GenerateNewStrict(MacroAssembler* masm) {
+  // Stack layout on entry.
+  //  jssp[0]:  number of parameters (tagged)
+  //  jssp[8]:  address of receiver argument
+  //  jssp[16]: function
+  //
+  // Returns pointer to result object in x0.
+
+  // Get the stub arguments from the frame, and make an untagged copy of the
+  // parameter count.
+  Register param_count_smi = x1;
+  Register params = x2;
+  Register function = x3;
+  Register param_count = x13;
+  __ Pop(param_count_smi, params, function);
+  __ SmiUntag(param_count, param_count_smi);
+
+  // Test if arguments adaptor needed.
+  Register caller_fp = x11;
+  Register caller_ctx = x12;
+  Label try_allocate, runtime;
+  __ Ldr(caller_fp, MemOperand(fp, StandardFrameConstants::kCallerFPOffset));
+  __ Ldr(caller_ctx, MemOperand(caller_fp,
+                                StandardFrameConstants::kContextOffset));
+  __ Cmp(caller_ctx, Smi::FromInt(StackFrame::ARGUMENTS_ADAPTOR));
+  __ B(ne, &try_allocate);
+
+  //   x1   param_count_smi   number of parameters passed to function (smi)
+  //   x2   params            pointer to parameters
+  //   x3   function          function pointer
+  //   x11  caller_fp         caller's frame pointer
+  //   x13  param_count       number of parameters passed to function
+
+  // Patch the argument length and parameters pointer.
+  __ Ldr(param_count_smi,
+         MemOperand(caller_fp,
+                    ArgumentsAdaptorFrameConstants::kLengthOffset));
+  __ SmiUntag(param_count, param_count_smi);
+  __ Add(x10, caller_fp, Operand(param_count, LSL, kPointerSizeLog2));
+  __ Add(params, x10, StandardFrameConstants::kCallerSPOffset);
+
+  // Try the new space allocation. Start out with computing the size of the
+  // arguments object and the elements array in words.
+  Register size = x10;
+  __ Bind(&try_allocate);
+  __ Add(size, param_count, FixedArray::kHeaderSize / kPointerSize);
+  __ Cmp(param_count, 0);
+  __ CzeroX(size, eq);
+  __ Add(size, size, Heap::kStrictArgumentsObjectSize / kPointerSize);
+
+  // Do the allocation of both objects in one go. Assign this to x0, as it will
+  // be returned to the caller.
+  Register alloc_obj = x0;
+  __ Allocate(size, alloc_obj, x11, x12, &runtime,
+              static_cast<AllocationFlags>(TAG_OBJECT | SIZE_IN_WORDS));
+
+  // Get the arguments boilerplate from the current (native) context.
+  Register global_object = x10;
+  Register global_ctx = x10;
+  Register strict_args_map = x4;
+  __ Ldr(global_object, GlobalObjectMemOperand());
+  __ Ldr(global_ctx, FieldMemOperand(global_object,
+                                     GlobalObject::kNativeContextOffset));
+  __ Ldr(strict_args_map,
+         ContextMemOperand(global_ctx, Context::STRICT_ARGUMENTS_MAP_INDEX));
+
+  //   x0   alloc_obj         pointer to allocated objects: parameter array and
+  //                          arguments object
+  //   x1   param_count_smi   number of parameters passed to function (smi)
+  //   x2   params            pointer to parameters
+  //   x3   function          function pointer
+  //   x4   strict_args_map   offset to arguments map
+  //   x13  param_count       number of parameters passed to function
+  __ Str(strict_args_map, FieldMemOperand(alloc_obj, JSObject::kMapOffset));
+  __ LoadRoot(x5, Heap::kEmptyFixedArrayRootIndex);
+  __ Str(x5, FieldMemOperand(alloc_obj, JSObject::kPropertiesOffset));
+  __ Str(x5, FieldMemOperand(alloc_obj, JSObject::kElementsOffset));
+
+  // Set the smi-tagged length as an in-object property.
+  STATIC_ASSERT(Heap::kArgumentsLengthIndex == 0);
+  const int kLengthOffset = JSObject::kHeaderSize +
+                            Heap::kArgumentsLengthIndex * kPointerSize;
+  __ Str(param_count_smi, FieldMemOperand(alloc_obj, kLengthOffset));
+
+  // If there are no actual arguments, we're done.
+  Label done;
+  __ Cbz(param_count, &done);
+
+  // Set up the elements pointer in the allocated arguments object and
+  // initialize the header in the elements fixed array.
+  Register elements = x5;
+  __ Add(elements, alloc_obj, Heap::kStrictArgumentsObjectSize);
+  __ Str(elements, FieldMemOperand(alloc_obj, JSObject::kElementsOffset));
+  __ LoadRoot(x10, Heap::kFixedArrayMapRootIndex);
+  __ Str(x10, FieldMemOperand(elements, FixedArray::kMapOffset));
+  __ Str(param_count_smi, FieldMemOperand(elements, FixedArray::kLengthOffset));
+
+  //   x0   alloc_obj         pointer to allocated objects: parameter array and
+  //                          arguments object
+  //   x1   param_count_smi   number of parameters passed to function (smi)
+  //   x2   params            pointer to parameters
+  //   x3   function          function pointer
+  //   x4   array             pointer to array slot (uninit)
+  //   x5   elements          pointer to elements array of alloc_obj
+  //   x13  param_count       number of parameters passed to function
+
+  // Copy the fixed array slots.
+  Label loop;
+  Register array = x4;
+  // Set up pointer to first array slot.
+  __ Add(array, elements, FixedArray::kHeaderSize - kHeapObjectTag);
+
+  __ Bind(&loop);
+  // Pre-decrement the parameters pointer by kPointerSize on each iteration.
+  // Pre-decrement in order to skip receiver.
+  __ Ldr(x10, MemOperand(params, -kPointerSize, PreIndex));
+  // Post-increment elements by kPointerSize on each iteration.
+  __ Str(x10, MemOperand(array, kPointerSize, PostIndex));
+  __ Sub(param_count, param_count, 1);
+  __ Cbnz(param_count, &loop);
+
+  // Return from stub.
+  __ Bind(&done);
+  __ Ret();
+
+  // Do the runtime call to allocate the arguments object.
+  __ Bind(&runtime);
+  __ Push(function, params, param_count_smi);
+  __ TailCallRuntime(Runtime::kNewStrictArguments, 3, 1);
+}
+
+
+void RegExpExecStub::Generate(MacroAssembler* masm) {
+#ifdef V8_INTERPRETED_REGEXP
+  __ TailCallRuntime(Runtime::kRegExpExecRT, 4, 1);
+#else  // V8_INTERPRETED_REGEXP
+
+  // Stack frame on entry.
+  //  jssp[0]: last_match_info (expected JSArray)
+  //  jssp[8]: previous index
+  //  jssp[16]: subject string
+  //  jssp[24]: JSRegExp object
+  Label runtime;
+
+  // Use of registers for this function.
+
+  // Variable registers:
+  //   x10-x13                                  used as scratch registers
+  //   w0       string_type                     type of subject string
+  //   x2       jsstring_length                 subject string length
+  //   x3       jsregexp_object                 JSRegExp object
+  //   w4       string_encoding                 Latin1 or UC16
+  //   w5       sliced_string_offset            if the string is a SlicedString
+  //                                            offset to the underlying string
+  //   w6       string_representation           groups attributes of the string:
+  //                                              - is a string
+  //                                              - type of the string
+  //                                              - is a short external string
+  Register string_type = w0;
+  Register jsstring_length = x2;
+  Register jsregexp_object = x3;
+  Register string_encoding = w4;
+  Register sliced_string_offset = w5;
+  Register string_representation = w6;
+
+  // These are in callee save registers and will be preserved by the call
+  // to the native RegExp code, as this code is called using the normal
+  // C calling convention. When calling directly from generated code the
+  // native RegExp code will not do a GC and therefore the content of
+  // these registers are safe to use after the call.
+
+  //   x19       subject                        subject string
+  //   x20       regexp_data                    RegExp data (FixedArray)
+  //   x21       last_match_info_elements       info relative to the last match
+  //                                            (FixedArray)
+  //   x22       code_object                    generated regexp code
+  Register subject = x19;
+  Register regexp_data = x20;
+  Register last_match_info_elements = x21;
+  Register code_object = x22;
+
+  // TODO(jbramley): Is it necessary to preserve these? I don't think ARM does.
+  CPURegList used_callee_saved_registers(subject,
+                                         regexp_data,
+                                         last_match_info_elements,
+                                         code_object);
+  __ PushCPURegList(used_callee_saved_registers);
+
+  // Stack frame.
+  //  jssp[0] : x19
+  //  jssp[8] : x20
+  //  jssp[16]: x21
+  //  jssp[24]: x22
+  //  jssp[32]: last_match_info (JSArray)
+  //  jssp[40]: previous index
+  //  jssp[48]: subject string
+  //  jssp[56]: JSRegExp object
+
+  const int kLastMatchInfoOffset = 4 * kPointerSize;
+  const int kPreviousIndexOffset = 5 * kPointerSize;
+  const int kSubjectOffset = 6 * kPointerSize;
+  const int kJSRegExpOffset = 7 * kPointerSize;
+
+  // Ensure that a RegExp stack is allocated.
+  ExternalReference address_of_regexp_stack_memory_address =
+      ExternalReference::address_of_regexp_stack_memory_address(isolate());
+  ExternalReference address_of_regexp_stack_memory_size =
+      ExternalReference::address_of_regexp_stack_memory_size(isolate());
+  __ Mov(x10, address_of_regexp_stack_memory_size);
+  __ Ldr(x10, MemOperand(x10));
+  __ Cbz(x10, &runtime);
+
+  // Check that the first argument is a JSRegExp object.
+  DCHECK(jssp.Is(__ StackPointer()));
+  __ Peek(jsregexp_object, kJSRegExpOffset);
+  __ JumpIfSmi(jsregexp_object, &runtime);
+  __ JumpIfNotObjectType(jsregexp_object, x10, x10, JS_REGEXP_TYPE, &runtime);
+
+  // Check that the RegExp has been compiled (data contains a fixed array).
+  __ Ldr(regexp_data, FieldMemOperand(jsregexp_object, JSRegExp::kDataOffset));
+  if (FLAG_debug_code) {
+    STATIC_ASSERT(kSmiTag == 0);
+    __ Tst(regexp_data, kSmiTagMask);
+    __ Check(ne, kUnexpectedTypeForRegExpDataFixedArrayExpected);
+    __ CompareObjectType(regexp_data, x10, x10, FIXED_ARRAY_TYPE);
+    __ Check(eq, kUnexpectedTypeForRegExpDataFixedArrayExpected);
+  }
+
+  // Check the type of the RegExp. Only continue if type is JSRegExp::IRREGEXP.
+  __ Ldr(x10, FieldMemOperand(regexp_data, JSRegExp::kDataTagOffset));
+  __ Cmp(x10, Smi::FromInt(JSRegExp::IRREGEXP));
+  __ B(ne, &runtime);
+
+  // Check that the number of captures fit in the static offsets vector buffer.
+  // We have always at least one capture for the whole match, plus additional
+  // ones due to capturing parentheses. A capture takes 2 registers.
+  // The number of capture registers then is (number_of_captures + 1) * 2.
+  __ Ldrsw(x10,
+           UntagSmiFieldMemOperand(regexp_data,
+                                   JSRegExp::kIrregexpCaptureCountOffset));
+  // Check (number_of_captures + 1) * 2 <= offsets vector size
+  //             number_of_captures * 2 <= offsets vector size - 2
+  STATIC_ASSERT(Isolate::kJSRegexpStaticOffsetsVectorSize >= 2);
+  __ Add(x10, x10, x10);
+  __ Cmp(x10, Isolate::kJSRegexpStaticOffsetsVectorSize - 2);
+  __ B(hi, &runtime);
+
+  // Initialize offset for possibly sliced string.
+  __ Mov(sliced_string_offset, 0);
+
+  DCHECK(jssp.Is(__ StackPointer()));
+  __ Peek(subject, kSubjectOffset);
+  __ JumpIfSmi(subject, &runtime);
+
+  __ Ldr(x10, FieldMemOperand(subject, HeapObject::kMapOffset));
+  __ Ldrb(string_type, FieldMemOperand(x10, Map::kInstanceTypeOffset));
+
+  __ Ldr(jsstring_length, FieldMemOperand(subject, String::kLengthOffset));
+
+  // Handle subject string according to its encoding and representation:
+  // (1) Sequential string?  If yes, go to (5).
+  // (2) Anything but sequential or cons?  If yes, go to (6).
+  // (3) Cons string.  If the string is flat, replace subject with first string.
+  //     Otherwise bailout.
+  // (4) Is subject external?  If yes, go to (7).
+  // (5) Sequential string.  Load regexp code according to encoding.
+  // (E) Carry on.
+  /// [...]
+
+  // Deferred code at the end of the stub:
+  // (6) Not a long external string?  If yes, go to (8).
+  // (7) External string.  Make it, offset-wise, look like a sequential string.
+  //     Go to (5).
+  // (8) Short external string or not a string?  If yes, bail out to runtime.
+  // (9) Sliced string.  Replace subject with parent.  Go to (4).
+
+  Label check_underlying;   // (4)
+  Label seq_string;         // (5)
+  Label not_seq_nor_cons;   // (6)
+  Label external_string;    // (7)
+  Label not_long_external;  // (8)
+
+  // (1) Sequential string?  If yes, go to (5).
+  __ And(string_representation,
+         string_type,
+         kIsNotStringMask |
+             kStringRepresentationMask |
+             kShortExternalStringMask);
+  // We depend on the fact that Strings of type
+  // SeqString and not ShortExternalString are defined
+  // by the following pattern:
+  //   string_type: 0XX0 XX00
+  //                ^  ^   ^^
+  //                |  |   ||
+  //                |  |   is a SeqString
+  //                |  is not a short external String
+  //                is a String
+  STATIC_ASSERT((kStringTag | kSeqStringTag) == 0);
+  STATIC_ASSERT(kShortExternalStringTag != 0);
+  __ Cbz(string_representation, &seq_string);  // Go to (5).
+
+  // (2) Anything but sequential or cons?  If yes, go to (6).
+  STATIC_ASSERT(kConsStringTag < kExternalStringTag);
+  STATIC_ASSERT(kSlicedStringTag > kExternalStringTag);
+  STATIC_ASSERT(kIsNotStringMask > kExternalStringTag);
+  STATIC_ASSERT(kShortExternalStringTag > kExternalStringTag);
+  __ Cmp(string_representation, kExternalStringTag);
+  __ B(ge, &not_seq_nor_cons);  // Go to (6).
+
+  // (3) Cons string.  Check that it's flat.
+  __ Ldr(x10, FieldMemOperand(subject, ConsString::kSecondOffset));
+  __ JumpIfNotRoot(x10, Heap::kempty_stringRootIndex, &runtime);
+  // Replace subject with first string.
+  __ Ldr(subject, FieldMemOperand(subject, ConsString::kFirstOffset));
+
+  // (4) Is subject external?  If yes, go to (7).
+  __ Bind(&check_underlying);
+  // Reload the string type.
+  __ Ldr(x10, FieldMemOperand(subject, HeapObject::kMapOffset));
+  __ Ldrb(string_type, FieldMemOperand(x10, Map::kInstanceTypeOffset));
+  STATIC_ASSERT(kSeqStringTag == 0);
+  // The underlying external string is never a short external string.
+  STATIC_ASSERT(ExternalString::kMaxShortLength < ConsString::kMinLength);
+  STATIC_ASSERT(ExternalString::kMaxShortLength < SlicedString::kMinLength);
+  __ TestAndBranchIfAnySet(string_type.X(),
+                           kStringRepresentationMask,
+                           &external_string);  // Go to (7).
+
+  // (5) Sequential string.  Load regexp code according to encoding.
+  __ Bind(&seq_string);
+
+  // Check that the third argument is a positive smi less than the subject
+  // string length. A negative value will be greater (unsigned comparison).
+  DCHECK(jssp.Is(__ StackPointer()));
+  __ Peek(x10, kPreviousIndexOffset);
+  __ JumpIfNotSmi(x10, &runtime);
+  __ Cmp(jsstring_length, x10);
+  __ B(ls, &runtime);
+
+  // Argument 2 (x1): We need to load argument 2 (the previous index) into x1
+  // before entering the exit frame.
+  __ SmiUntag(x1, x10);
+
+  // The third bit determines the string encoding in string_type.
+  STATIC_ASSERT(kOneByteStringTag == 0x04);
+  STATIC_ASSERT(kTwoByteStringTag == 0x00);
+  STATIC_ASSERT(kStringEncodingMask == 0x04);
+
+  // Find the code object based on the assumptions above.
+  // kDataOneByteCodeOffset and kDataUC16CodeOffset are adjacent, adds an offset
+  // of kPointerSize to reach the latter.
+  DCHECK_EQ(JSRegExp::kDataOneByteCodeOffset + kPointerSize,
+            JSRegExp::kDataUC16CodeOffset);
+  __ Mov(x10, kPointerSize);
+  // We will need the encoding later: Latin1 = 0x04
+  //                                  UC16   = 0x00
+  __ Ands(string_encoding, string_type, kStringEncodingMask);
+  __ CzeroX(x10, ne);
+  __ Add(x10, regexp_data, x10);
+  __ Ldr(code_object, FieldMemOperand(x10, JSRegExp::kDataOneByteCodeOffset));
+
+  // (E) Carry on.  String handling is done.
+
+  // Check that the irregexp code has been generated for the actual string
+  // encoding. If it has, the field contains a code object otherwise it contains
+  // a smi (code flushing support).
+  __ JumpIfSmi(code_object, &runtime);
+
+  // All checks done. Now push arguments for native regexp code.
+  __ IncrementCounter(isolate()->counters()->regexp_entry_native(), 1,
+                      x10,
+                      x11);
+
+  // Isolates: note we add an additional parameter here (isolate pointer).
+  __ EnterExitFrame(false, x10, 1);
+  DCHECK(csp.Is(__ StackPointer()));
+
+  // We have 9 arguments to pass to the regexp code, therefore we have to pass
+  // one on the stack and the rest as registers.
+
+  // Note that the placement of the argument on the stack isn't standard
+  // AAPCS64:
+  // csp[0]: Space for the return address placed by DirectCEntryStub.
+  // csp[8]: Argument 9, the current isolate address.
+
+  __ Mov(x10, ExternalReference::isolate_address(isolate()));
+  __ Poke(x10, kPointerSize);
+
+  Register length = w11;
+  Register previous_index_in_bytes = w12;
+  Register start = x13;
+
+  // Load start of the subject string.
+  __ Add(start, subject, SeqString::kHeaderSize - kHeapObjectTag);
+  // Load the length from the original subject string from the previous stack
+  // frame. Therefore we have to use fp, which points exactly to two pointer
+  // sizes below the previous sp. (Because creating a new stack frame pushes
+  // the previous fp onto the stack and decrements sp by 2 * kPointerSize.)
+  __ Ldr(subject, MemOperand(fp, kSubjectOffset + 2 * kPointerSize));
+  __ Ldr(length, UntagSmiFieldMemOperand(subject, String::kLengthOffset));
+
+  // Handle UC16 encoding, two bytes make one character.
+  //   string_encoding: if Latin1: 0x04
+  //                    if UC16:   0x00
+  STATIC_ASSERT(kStringEncodingMask == 0x04);
+  __ Ubfx(string_encoding, string_encoding, 2, 1);
+  __ Eor(string_encoding, string_encoding, 1);
+  //   string_encoding: if Latin1: 0
+  //                    if UC16:   1
+
+  // Convert string positions from characters to bytes.
+  // Previous index is in x1.
+  __ Lsl(previous_index_in_bytes, w1, string_encoding);
+  __ Lsl(length, length, string_encoding);
+  __ Lsl(sliced_string_offset, sliced_string_offset, string_encoding);
+
+  // Argument 1 (x0): Subject string.
+  __ Mov(x0, subject);
+
+  // Argument 2 (x1): Previous index, already there.
+
+  // Argument 3 (x2): Get the start of input.
+  // Start of input = start of string + previous index + substring offset
+  //                                                     (0 if the string
+  //                                                      is not sliced).
+  __ Add(w10, previous_index_in_bytes, sliced_string_offset);
+  __ Add(x2, start, Operand(w10, UXTW));
+
+  // Argument 4 (x3):
+  // End of input = start of input + (length of input - previous index)
+  __ Sub(w10, length, previous_index_in_bytes);
+  __ Add(x3, x2, Operand(w10, UXTW));
+
+  // Argument 5 (x4): static offsets vector buffer.
+  __ Mov(x4, ExternalReference::address_of_static_offsets_vector(isolate()));
+
+  // Argument 6 (x5): Set the number of capture registers to zero to force
+  // global regexps to behave as non-global. This stub is not used for global
+  // regexps.
+  __ Mov(x5, 0);
+
+  // Argument 7 (x6): Start (high end) of backtracking stack memory area.
+  __ Mov(x10, address_of_regexp_stack_memory_address);
+  __ Ldr(x10, MemOperand(x10));
+  __ Mov(x11, address_of_regexp_stack_memory_size);
+  __ Ldr(x11, MemOperand(x11));
+  __ Add(x6, x10, x11);
+
+  // Argument 8 (x7): Indicate that this is a direct call from JavaScript.
+  __ Mov(x7, 1);
+
+  // Locate the code entry and call it.
+  __ Add(code_object, code_object, Code::kHeaderSize - kHeapObjectTag);
+  DirectCEntryStub stub(isolate());
+  stub.GenerateCall(masm, code_object);
+
+  __ LeaveExitFrame(false, x10, true);
+
+  // The generated regexp code returns an int32 in w0.
+  Label failure, exception;
+  __ CompareAndBranch(w0, NativeRegExpMacroAssembler::FAILURE, eq, &failure);
+  __ CompareAndBranch(w0,
+                      NativeRegExpMacroAssembler::EXCEPTION,
+                      eq,
+                      &exception);
+  __ CompareAndBranch(w0, NativeRegExpMacroAssembler::RETRY, eq, &runtime);
+
+  // Success: process the result from the native regexp code.
+  Register number_of_capture_registers = x12;
+
+  // Calculate number of capture registers (number_of_captures + 1) * 2
+  // and store it in the last match info.
+  __ Ldrsw(x10,
+           UntagSmiFieldMemOperand(regexp_data,
+                                   JSRegExp::kIrregexpCaptureCountOffset));
+  __ Add(x10, x10, x10);
+  __ Add(number_of_capture_registers, x10, 2);
+
+  // Check that the fourth object is a JSArray object.
+  DCHECK(jssp.Is(__ StackPointer()));
+  __ Peek(x10, kLastMatchInfoOffset);
+  __ JumpIfSmi(x10, &runtime);
+  __ JumpIfNotObjectType(x10, x11, x11, JS_ARRAY_TYPE, &runtime);
+
+  // Check that the JSArray is the fast case.
+  __ Ldr(last_match_info_elements,
+         FieldMemOperand(x10, JSArray::kElementsOffset));
+  __ Ldr(x10,
+         FieldMemOperand(last_match_info_elements, HeapObject::kMapOffset));
+  __ JumpIfNotRoot(x10, Heap::kFixedArrayMapRootIndex, &runtime);
+
+  // Check that the last match info has space for the capture registers and the
+  // additional information (overhead).
+  //     (number_of_captures + 1) * 2 + overhead <= last match info size
+  //     (number_of_captures * 2) + 2 + overhead <= last match info size
+  //      number_of_capture_registers + overhead <= last match info size
+  __ Ldrsw(x10,
+           UntagSmiFieldMemOperand(last_match_info_elements,
+                                   FixedArray::kLengthOffset));
+  __ Add(x11, number_of_capture_registers, RegExpImpl::kLastMatchOverhead);
+  __ Cmp(x11, x10);
+  __ B(gt, &runtime);
+
+  // Store the capture count.
+  __ SmiTag(x10, number_of_capture_registers);
+  __ Str(x10,
+         FieldMemOperand(last_match_info_elements,
+                         RegExpImpl::kLastCaptureCountOffset));
+  // Store last subject and last input.
+  __ Str(subject,
+         FieldMemOperand(last_match_info_elements,
+                         RegExpImpl::kLastSubjectOffset));
+  // Use x10 as the subject string in order to only need
+  // one RecordWriteStub.
+  __ Mov(x10, subject);
+  __ RecordWriteField(last_match_info_elements,
+                      RegExpImpl::kLastSubjectOffset,
+                      x10,
+                      x11,
+                      kLRHasNotBeenSaved,
+                      kDontSaveFPRegs);
+  __ Str(subject,
+         FieldMemOperand(last_match_info_elements,
+                         RegExpImpl::kLastInputOffset));
+  __ Mov(x10, subject);
+  __ RecordWriteField(last_match_info_elements,
+                      RegExpImpl::kLastInputOffset,
+                      x10,
+                      x11,
+                      kLRHasNotBeenSaved,
+                      kDontSaveFPRegs);
+
+  Register last_match_offsets = x13;
+  Register offsets_vector_index = x14;
+  Register current_offset = x15;
+
+  // Get the static offsets vector filled by the native regexp code
+  // and fill the last match info.
+  ExternalReference address_of_static_offsets_vector =
+      ExternalReference::address_of_static_offsets_vector(isolate());
+  __ Mov(offsets_vector_index, address_of_static_offsets_vector);
+
+  Label next_capture, done;
+  // Capture register counter starts from number of capture registers and
+  // iterates down to zero (inclusive).
+  __ Add(last_match_offsets,
+         last_match_info_elements,
+         RegExpImpl::kFirstCaptureOffset - kHeapObjectTag);
+  __ Bind(&next_capture);
+  __ Subs(number_of_capture_registers, number_of_capture_registers, 2);
+  __ B(mi, &done);
+  // Read two 32 bit values from the static offsets vector buffer into
+  // an X register
+  __ Ldr(current_offset,
+         MemOperand(offsets_vector_index, kWRegSize * 2, PostIndex));
+  // Store the smi values in the last match info.
+  __ SmiTag(x10, current_offset);
+  // Clearing the 32 bottom bits gives us a Smi.
+  STATIC_ASSERT(kSmiTag == 0);
+  __ Bic(x11, current_offset, kSmiShiftMask);
+  __ Stp(x10,
+         x11,
+         MemOperand(last_match_offsets, kXRegSize * 2, PostIndex));
+  __ B(&next_capture);
+  __ Bind(&done);
+
+  // Return last match info.
+  __ Peek(x0, kLastMatchInfoOffset);
+  __ PopCPURegList(used_callee_saved_registers);
+  // Drop the 4 arguments of the stub from the stack.
+  __ Drop(4);
+  __ Ret();
+
+  __ Bind(&exception);
+  Register exception_value = x0;
+  // A stack overflow (on the backtrack stack) may have occured
+  // in the RegExp code but no exception has been created yet.
+  // If there is no pending exception, handle that in the runtime system.
+  __ Mov(x10, Operand(isolate()->factory()->the_hole_value()));
+  __ Mov(x11,
+         Operand(ExternalReference(Isolate::kPendingExceptionAddress,
+                                   isolate())));
+  __ Ldr(exception_value, MemOperand(x11));
+  __ Cmp(x10, exception_value);
+  __ B(eq, &runtime);
+
+  __ Str(x10, MemOperand(x11));  // Clear pending exception.
+
+  // Check if the exception is a termination. If so, throw as uncatchable.
+  Label termination_exception;
+  __ JumpIfRoot(exception_value,
+                Heap::kTerminationExceptionRootIndex,
+                &termination_exception);
+
+  __ Throw(exception_value, x10, x11, x12, x13);
+
+  __ Bind(&termination_exception);
+  __ ThrowUncatchable(exception_value, x10, x11, x12, x13);
+
+  __ Bind(&failure);
+  __ Mov(x0, Operand(isolate()->factory()->null_value()));
+  __ PopCPURegList(used_callee_saved_registers);
+  // Drop the 4 arguments of the stub from the stack.
+  __ Drop(4);
+  __ Ret();
+
+  __ Bind(&runtime);
+  __ PopCPURegList(used_callee_saved_registers);
+  __ TailCallRuntime(Runtime::kRegExpExecRT, 4, 1);
+
+  // Deferred code for string handling.
+  // (6) Not a long external string?  If yes, go to (8).
+  __ Bind(&not_seq_nor_cons);
+  // Compare flags are still set.
+  __ B(ne, &not_long_external);  // Go to (8).
+
+  // (7) External string. Make it, offset-wise, look like a sequential string.
+  __ Bind(&external_string);
+  if (masm->emit_debug_code()) {
+    // Assert that we do not have a cons or slice (indirect strings) here.
+    // Sequential strings have already been ruled out.
+    __ Ldr(x10, FieldMemOperand(subject, HeapObject::kMapOffset));
+    __ Ldrb(x10, FieldMemOperand(x10, Map::kInstanceTypeOffset));
+    __ Tst(x10, kIsIndirectStringMask);
+    __ Check(eq, kExternalStringExpectedButNotFound);
+    __ And(x10, x10, kStringRepresentationMask);
+    __ Cmp(x10, 0);
+    __ Check(ne, kExternalStringExpectedButNotFound);
+  }
+  __ Ldr(subject,
+         FieldMemOperand(subject, ExternalString::kResourceDataOffset));
+  // Move the pointer so that offset-wise, it looks like a sequential string.
+  STATIC_ASSERT(SeqTwoByteString::kHeaderSize == SeqOneByteString::kHeaderSize);
+  __ Sub(subject, subject, SeqTwoByteString::kHeaderSize - kHeapObjectTag);
+  __ B(&seq_string);    // Go to (5).
+
+  // (8) If this is a short external string or not a string, bail out to
+  // runtime.
+  __ Bind(&not_long_external);
+  STATIC_ASSERT(kShortExternalStringTag != 0);
+  __ TestAndBranchIfAnySet(string_representation,
+                           kShortExternalStringMask | kIsNotStringMask,
+                           &runtime);
+
+  // (9) Sliced string. Replace subject with parent.
+  __ Ldr(sliced_string_offset,
+         UntagSmiFieldMemOperand(subject, SlicedString::kOffsetOffset));
+  __ Ldr(subject, FieldMemOperand(subject, SlicedString::kParentOffset));
+  __ B(&check_underlying);    // Go to (4).
+#endif
+}
+
+
+static void GenerateRecordCallTarget(MacroAssembler* masm,
+                                     Register argc,
+                                     Register function,
+                                     Register feedback_vector,
+                                     Register index,
+                                     Register scratch1,
+                                     Register scratch2) {
+  ASM_LOCATION("GenerateRecordCallTarget");
+  DCHECK(!AreAliased(scratch1, scratch2,
+                     argc, function, feedback_vector, index));
+  // Cache the called function in a feedback vector slot. Cache states are
+  // uninitialized, monomorphic (indicated by a JSFunction), and megamorphic.
+  //  argc :            number of arguments to the construct function
+  //  function :        the function to call
+  //  feedback_vector : the feedback vector
+  //  index :           slot in feedback vector (smi)
+  Label initialize, done, miss, megamorphic, not_array_function;
+
+  DCHECK_EQ(*TypeFeedbackVector::MegamorphicSentinel(masm->isolate()),
+            masm->isolate()->heap()->megamorphic_symbol());
+  DCHECK_EQ(*TypeFeedbackVector::UninitializedSentinel(masm->isolate()),
+            masm->isolate()->heap()->uninitialized_symbol());
+
+  // Load the cache state.
+  __ Add(scratch1, feedback_vector,
+         Operand::UntagSmiAndScale(index, kPointerSizeLog2));
+  __ Ldr(scratch1, FieldMemOperand(scratch1, FixedArray::kHeaderSize));
+
+  // A monomorphic cache hit or an already megamorphic state: invoke the
+  // function without changing the state.
+  __ Cmp(scratch1, function);
+  __ B(eq, &done);
+
+  if (!FLAG_pretenuring_call_new) {
+    // If we came here, we need to see if we are the array function.
+    // If we didn't have a matching function, and we didn't find the megamorph
+    // sentinel, then we have in the slot either some other function or an
+    // AllocationSite. Do a map check on the object in scratch1 register.
+    __ Ldr(scratch2, FieldMemOperand(scratch1, AllocationSite::kMapOffset));
+    __ JumpIfNotRoot(scratch2, Heap::kAllocationSiteMapRootIndex, &miss);
+
+    // Make sure the function is the Array() function
+    __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, scratch1);
+    __ Cmp(function, scratch1);
+    __ B(ne, &megamorphic);
+    __ B(&done);
+  }
+
+  __ Bind(&miss);
+
+  // A monomorphic miss (i.e, here the cache is not uninitialized) goes
+  // megamorphic.
+  __ JumpIfRoot(scratch1, Heap::kUninitializedSymbolRootIndex, &initialize);
+  // MegamorphicSentinel is an immortal immovable object (undefined) so no
+  // write-barrier is needed.
+  __ Bind(&megamorphic);
+  __ Add(scratch1, feedback_vector,
+         Operand::UntagSmiAndScale(index, kPointerSizeLog2));
+  __ LoadRoot(scratch2, Heap::kMegamorphicSymbolRootIndex);
+  __ Str(scratch2, FieldMemOperand(scratch1, FixedArray::kHeaderSize));
+  __ B(&done);
+
+  // An uninitialized cache is patched with the function or sentinel to
+  // indicate the ElementsKind if function is the Array constructor.
+  __ Bind(&initialize);
+
+  if (!FLAG_pretenuring_call_new) {
+    // Make sure the function is the Array() function
+    __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, scratch1);
+    __ Cmp(function, scratch1);
+    __ B(ne, &not_array_function);
+
+    // The target function is the Array constructor,
+    // Create an AllocationSite if we don't already have it, store it in the
+    // slot.
+    {
+      FrameScope scope(masm, StackFrame::INTERNAL);
+      CreateAllocationSiteStub create_stub(masm->isolate());
+
+      // Arguments register must be smi-tagged to call out.
+      __ SmiTag(argc);
+      __ Push(argc, function, feedback_vector, index);
+
+      // CreateAllocationSiteStub expect the feedback vector in x2 and the slot
+      // index in x3.
+      DCHECK(feedback_vector.Is(x2) && index.Is(x3));
+      __ CallStub(&create_stub);
+
+      __ Pop(index, feedback_vector, function, argc);
+      __ SmiUntag(argc);
+    }
+    __ B(&done);
+
+    __ Bind(&not_array_function);
+  }
+
+  // An uninitialized cache is patched with the function.
+
+  __ Add(scratch1, feedback_vector,
+         Operand::UntagSmiAndScale(index, kPointerSizeLog2));
+  __ Add(scratch1, scratch1, FixedArray::kHeaderSize - kHeapObjectTag);
+  __ Str(function, MemOperand(scratch1, 0));
+
+  __ Push(function);
+  __ RecordWrite(feedback_vector, scratch1, function, kLRHasNotBeenSaved,
+                 kDontSaveFPRegs, EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+  __ Pop(function);
+
+  __ Bind(&done);
+}
+
+
+static void EmitContinueIfStrictOrNative(MacroAssembler* masm, Label* cont) {
+  // Do not transform the receiver for strict mode functions.
+  __ Ldr(x3, FieldMemOperand(x1, JSFunction::kSharedFunctionInfoOffset));
+  __ Ldr(w4, FieldMemOperand(x3, SharedFunctionInfo::kCompilerHintsOffset));
+  __ Tbnz(w4, SharedFunctionInfo::kStrictModeFunction, cont);
+
+  // Do not transform the receiver for native (Compilerhints already in x3).
+  __ Tbnz(w4, SharedFunctionInfo::kNative, cont);
+}
+
+
+static void EmitSlowCase(MacroAssembler* masm,
+                         int argc,
+                         Register function,
+                         Register type,
+                         Label* non_function) {
+  // Check for function proxy.
+  // x10 : function type.
+  __ CompareAndBranch(type, JS_FUNCTION_PROXY_TYPE, ne, non_function);
+  __ Push(function);  // put proxy as additional argument
+  __ Mov(x0, argc + 1);
+  __ Mov(x2, 0);
+  __ GetBuiltinFunction(x1, Builtins::CALL_FUNCTION_PROXY);
+  {
+    Handle<Code> adaptor =
+        masm->isolate()->builtins()->ArgumentsAdaptorTrampoline();
+    __ Jump(adaptor, RelocInfo::CODE_TARGET);
+  }
+
+  // CALL_NON_FUNCTION expects the non-function callee as receiver (instead
+  // of the original receiver from the call site).
+  __ Bind(non_function);
+  __ Poke(function, argc * kXRegSize);
+  __ Mov(x0, argc);  // Set up the number of arguments.
+  __ Mov(x2, 0);
+  __ GetBuiltinFunction(function, Builtins::CALL_NON_FUNCTION);
+  __ Jump(masm->isolate()->builtins()->ArgumentsAdaptorTrampoline(),
+          RelocInfo::CODE_TARGET);
+}
+
+
+static void EmitWrapCase(MacroAssembler* masm, int argc, Label* cont) {
+  // Wrap the receiver and patch it back onto the stack.
+  { FrameScope frame_scope(masm, StackFrame::INTERNAL);
+    __ Push(x1, x3);
+    __ InvokeBuiltin(Builtins::TO_OBJECT, CALL_FUNCTION);
+    __ Pop(x1);
+  }
+  __ Poke(x0, argc * kPointerSize);
+  __ B(cont);
+}
+
+
+static void CallFunctionNoFeedback(MacroAssembler* masm,
+                                   int argc, bool needs_checks,
+                                   bool call_as_method) {
+  // x1  function    the function to call
+  Register function = x1;
+  Register type = x4;
+  Label slow, non_function, wrap, cont;
+
+  // TODO(jbramley): This function has a lot of unnamed registers. Name them,
+  // and tidy things up a bit.
+
+  if (needs_checks) {
+    // Check that the function is really a JavaScript function.
+    __ JumpIfSmi(function, &non_function);
+
+    // Goto slow case if we do not have a function.
+    __ JumpIfNotObjectType(function, x10, type, JS_FUNCTION_TYPE, &slow);
+  }
+
+  // Fast-case: Invoke the function now.
+  // x1  function  pushed function
+  ParameterCount actual(argc);
+
+  if (call_as_method) {
+    if (needs_checks) {
+      EmitContinueIfStrictOrNative(masm, &cont);
+    }
+
+    // Compute the receiver in sloppy mode.
+    __ Peek(x3, argc * kPointerSize);
+
+    if (needs_checks) {
+      __ JumpIfSmi(x3, &wrap);
+      __ JumpIfObjectType(x3, x10, type, FIRST_SPEC_OBJECT_TYPE, &wrap, lt);
+    } else {
+      __ B(&wrap);
+    }
+
+    __ Bind(&cont);
+  }
+
+  __ InvokeFunction(function,
+                    actual,
+                    JUMP_FUNCTION,
+                    NullCallWrapper());
+  if (needs_checks) {
+    // Slow-case: Non-function called.
+    __ Bind(&slow);
+    EmitSlowCase(masm, argc, function, type, &non_function);
+  }
+
+  if (call_as_method) {
+    __ Bind(&wrap);
+    EmitWrapCase(masm, argc, &cont);
+  }
+}
+
+
+void CallFunctionStub::Generate(MacroAssembler* masm) {
+  ASM_LOCATION("CallFunctionStub::Generate");
+  CallFunctionNoFeedback(masm, argc(), NeedsChecks(), CallAsMethod());
+}
+
+
+void CallConstructStub::Generate(MacroAssembler* masm) {
+  ASM_LOCATION("CallConstructStub::Generate");
+  // x0 : number of arguments
+  // x1 : the function to call
+  // x2 : feedback vector
+  // x3 : slot in feedback vector (smi) (if r2 is not the megamorphic symbol)
+  Register function = x1;
+  Label slow, non_function_call;
+
+  // Check that the function is not a smi.
+  __ JumpIfSmi(function, &non_function_call);
+  // Check that the function is a JSFunction.
+  Register object_type = x10;
+  __ JumpIfNotObjectType(function, object_type, object_type, JS_FUNCTION_TYPE,
+                         &slow);
+
+  if (RecordCallTarget()) {
+    GenerateRecordCallTarget(masm, x0, function, x2, x3, x4, x5);
+
+    __ Add(x5, x2, Operand::UntagSmiAndScale(x3, kPointerSizeLog2));
+    if (FLAG_pretenuring_call_new) {
+      // Put the AllocationSite from the feedback vector into x2.
+      // By adding kPointerSize we encode that we know the AllocationSite
+      // entry is at the feedback vector slot given by x3 + 1.
+      __ Ldr(x2, FieldMemOperand(x5, FixedArray::kHeaderSize + kPointerSize));
+    } else {
+    Label feedback_register_initialized;
+      // Put the AllocationSite from the feedback vector into x2, or undefined.
+      __ Ldr(x2, FieldMemOperand(x5, FixedArray::kHeaderSize));
+      __ Ldr(x5, FieldMemOperand(x2, AllocationSite::kMapOffset));
+      __ JumpIfRoot(x5, Heap::kAllocationSiteMapRootIndex,
+                    &feedback_register_initialized);
+      __ LoadRoot(x2, Heap::kUndefinedValueRootIndex);
+      __ bind(&feedback_register_initialized);
+    }
+
+    __ AssertUndefinedOrAllocationSite(x2, x5);
+  }
+
+  // Jump to the function-specific construct stub.
+  Register jump_reg = x4;
+  Register shared_func_info = jump_reg;
+  Register cons_stub = jump_reg;
+  Register cons_stub_code = jump_reg;
+  __ Ldr(shared_func_info,
+         FieldMemOperand(function, JSFunction::kSharedFunctionInfoOffset));
+  __ Ldr(cons_stub,
+         FieldMemOperand(shared_func_info,
+                         SharedFunctionInfo::kConstructStubOffset));
+  __ Add(cons_stub_code, cons_stub, Code::kHeaderSize - kHeapObjectTag);
+  __ Br(cons_stub_code);
+
+  Label do_call;
+  __ Bind(&slow);
+  __ Cmp(object_type, JS_FUNCTION_PROXY_TYPE);
+  __ B(ne, &non_function_call);
+  __ GetBuiltinFunction(x1, Builtins::CALL_FUNCTION_PROXY_AS_CONSTRUCTOR);
+  __ B(&do_call);
+
+  __ Bind(&non_function_call);
+  __ GetBuiltinFunction(x1, Builtins::CALL_NON_FUNCTION_AS_CONSTRUCTOR);
+
+  __ Bind(&do_call);
+  // Set expected number of arguments to zero (not changing x0).
+  __ Mov(x2, 0);
+  __ Jump(isolate()->builtins()->ArgumentsAdaptorTrampoline(),
+          RelocInfo::CODE_TARGET);
+}
+
+
+static void EmitLoadTypeFeedbackVector(MacroAssembler* masm, Register vector) {
+  __ Ldr(vector, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
+  __ Ldr(vector, FieldMemOperand(vector,
+                                 JSFunction::kSharedFunctionInfoOffset));
+  __ Ldr(vector, FieldMemOperand(vector,
+                                 SharedFunctionInfo::kFeedbackVectorOffset));
+}
+
+
+void CallIC_ArrayStub::Generate(MacroAssembler* masm) {
+  // x1 - function
+  // x3 - slot id
+  Label miss;
+  Register function = x1;
+  Register feedback_vector = x2;
+  Register index = x3;
+  Register scratch = x4;
+
+  EmitLoadTypeFeedbackVector(masm, feedback_vector);
+
+  __ LoadGlobalFunction(Context::ARRAY_FUNCTION_INDEX, scratch);
+  __ Cmp(function, scratch);
+  __ B(ne, &miss);
+
+  __ Mov(x0, Operand(arg_count()));
+
+  __ Add(scratch, feedback_vector,
+         Operand::UntagSmiAndScale(index, kPointerSizeLog2));
+  __ Ldr(scratch, FieldMemOperand(scratch, FixedArray::kHeaderSize));
+
+  // Verify that scratch contains an AllocationSite
+  Register map = x5;
+  __ Ldr(map, FieldMemOperand(scratch, HeapObject::kMapOffset));
+  __ JumpIfNotRoot(map, Heap::kAllocationSiteMapRootIndex, &miss);
+
+  Register allocation_site = feedback_vector;
+  __ Mov(allocation_site, scratch);
+  ArrayConstructorStub stub(masm->isolate(), arg_count());
+  __ TailCallStub(&stub);
+
+  __ bind(&miss);
+  GenerateMiss(masm);
+
+  // The slow case, we need this no matter what to complete a call after a miss.
+  CallFunctionNoFeedback(masm,
+                         arg_count(),
+                         true,
+                         CallAsMethod());
+
+  __ Unreachable();
+}
+
+
+void CallICStub::Generate(MacroAssembler* masm) {
+  ASM_LOCATION("CallICStub");
+
+  // x1 - function
+  // x3 - slot id (Smi)
+  Label extra_checks_or_miss, slow_start;
+  Label slow, non_function, wrap, cont;
+  Label have_js_function;
+  int argc = arg_count();
+  ParameterCount actual(argc);
+
+  Register function = x1;
+  Register feedback_vector = x2;
+  Register index = x3;
+  Register type = x4;
+
+  EmitLoadTypeFeedbackVector(masm, feedback_vector);
+
+  // The checks. First, does x1 match the recorded monomorphic target?
+  __ Add(x4, feedback_vector,
+         Operand::UntagSmiAndScale(index, kPointerSizeLog2));
+  __ Ldr(x4, FieldMemOperand(x4, FixedArray::kHeaderSize));
+
+  __ Cmp(x4, function);
+  __ B(ne, &extra_checks_or_miss);
+
+  __ bind(&have_js_function);
+  if (CallAsMethod()) {
+    EmitContinueIfStrictOrNative(masm, &cont);
+
+    // Compute the receiver in sloppy mode.
+    __ Peek(x3, argc * kPointerSize);
+
+    __ JumpIfSmi(x3, &wrap);
+    __ JumpIfObjectType(x3, x10, type, FIRST_SPEC_OBJECT_TYPE, &wrap, lt);
+
+    __ Bind(&cont);
+  }
+
+  __ InvokeFunction(function,
+                    actual,
+                    JUMP_FUNCTION,
+                    NullCallWrapper());
+
+  __ bind(&slow);
+  EmitSlowCase(masm, argc, function, type, &non_function);
+
+  if (CallAsMethod()) {
+    __ bind(&wrap);
+    EmitWrapCase(masm, argc, &cont);
+  }
+
+  __ bind(&extra_checks_or_miss);
+  Label miss;
+
+  __ JumpIfRoot(x4, Heap::kMegamorphicSymbolRootIndex, &slow_start);
+  __ JumpIfRoot(x4, Heap::kUninitializedSymbolRootIndex, &miss);
+
+  if (!FLAG_trace_ic) {
+    // We are going megamorphic. If the feedback is a JSFunction, it is fine
+    // to handle it here. More complex cases are dealt with in the runtime.
+    __ AssertNotSmi(x4);
+    __ JumpIfNotObjectType(x4, x5, x5, JS_FUNCTION_TYPE, &miss);
+    __ Add(x4, feedback_vector,
+           Operand::UntagSmiAndScale(index, kPointerSizeLog2));
+    __ LoadRoot(x5, Heap::kMegamorphicSymbolRootIndex);
+    __ Str(x5, FieldMemOperand(x4, FixedArray::kHeaderSize));
+    __ B(&slow_start);
+  }
+
+  // We are here because tracing is on or we are going monomorphic.
+  __ bind(&miss);
+  GenerateMiss(masm);
+
+  // the slow case
+  __ bind(&slow_start);
+
+  // Check that the function is really a JavaScript function.
+  __ JumpIfSmi(function, &non_function);
+
+  // Goto slow case if we do not have a function.
+  __ JumpIfNotObjectType(function, x10, type, JS_FUNCTION_TYPE, &slow);
+  __ B(&have_js_function);
+}
+
+
+void CallICStub::GenerateMiss(MacroAssembler* masm) {
+  ASM_LOCATION("CallICStub[Miss]");
+
+  // Get the receiver of the function from the stack; 1 ~ return address.
+  __ Peek(x4, (arg_count() + 1) * kPointerSize);
+
+  {
+    FrameScope scope(masm, StackFrame::INTERNAL);
+
+    // Push the receiver and the function and feedback info.
+    __ Push(x4, x1, x2, x3);
+
+    // Call the entry.
+    IC::UtilityId id = GetICState() == DEFAULT ? IC::kCallIC_Miss
+                                               : IC::kCallIC_Customization_Miss;
+
+    ExternalReference miss = ExternalReference(IC_Utility(id),
+                                               masm->isolate());
+    __ CallExternalReference(miss, 4);
+
+    // Move result to edi and exit the internal frame.
+    __ Mov(x1, x0);
+  }
+}
+
+
+void StringCharCodeAtGenerator::GenerateFast(MacroAssembler* masm) {
+  // If the receiver is a smi trigger the non-string case.
+  __ JumpIfSmi(object_, receiver_not_string_);
+
+  // Fetch the instance type of the receiver into result register.
+  __ Ldr(result_, FieldMemOperand(object_, HeapObject::kMapOffset));
+  __ Ldrb(result_, FieldMemOperand(result_, Map::kInstanceTypeOffset));
+
+  // If the receiver is not a string trigger the non-string case.
+  __ TestAndBranchIfAnySet(result_, kIsNotStringMask, receiver_not_string_);
+
+  // If the index is non-smi trigger the non-smi case.
+  __ JumpIfNotSmi(index_, &index_not_smi_);
+
+  __ Bind(&got_smi_index_);
+  // Check for index out of range.
+  __ Ldrsw(result_, UntagSmiFieldMemOperand(object_, String::kLengthOffset));
+  __ Cmp(result_, Operand::UntagSmi(index_));
+  __ B(ls, index_out_of_range_);
+
+  __ SmiUntag(index_);
+
+  StringCharLoadGenerator::Generate(masm,
+                                    object_,
+                                    index_.W(),
+                                    result_,
+                                    &call_runtime_);
+  __ SmiTag(result_);
+  __ Bind(&exit_);
+}
+
+
+void StringCharCodeAtGenerator::GenerateSlow(
+    MacroAssembler* masm,
+    const RuntimeCallHelper& call_helper) {
+  __ Abort(kUnexpectedFallthroughToCharCodeAtSlowCase);
+
+  __ Bind(&index_not_smi_);
+  // If index is a heap number, try converting it to an integer.
+  __ JumpIfNotHeapNumber(index_, index_not_number_);
+  call_helper.BeforeCall(masm);
+  // Save object_ on the stack and pass index_ as argument for runtime call.
+  __ Push(object_, index_);
+  if (index_flags_ == STRING_INDEX_IS_NUMBER) {
+    __ CallRuntime(Runtime::kNumberToIntegerMapMinusZero, 1);
+  } else {
+    DCHECK(index_flags_ == STRING_INDEX_IS_ARRAY_INDEX);
+    // NumberToSmi discards numbers that are not exact integers.
+    __ CallRuntime(Runtime::kNumberToSmi, 1);
+  }
+  // Save the conversion result before the pop instructions below
+  // have a chance to overwrite it.
+  __ Mov(index_, x0);
+  __ Pop(object_);
+  // Reload the instance type.
+  __ Ldr(result_, FieldMemOperand(object_, HeapObject::kMapOffset));
+  __ Ldrb(result_, FieldMemOperand(result_, Map::kInstanceTypeOffset));
+  call_helper.AfterCall(masm);
+
+  // If index is still not a smi, it must be out of range.
+  __ JumpIfNotSmi(index_, index_out_of_range_);
+  // Otherwise, return to the fast path.
+  __ B(&got_smi_index_);
+
+  // Call runtime. We get here when the receiver is a string and the
+  // index is a number, but the code of getting the actual character
+  // is too complex (e.g., when the string needs to be flattened).
+  __ Bind(&call_runtime_);
+  call_helper.BeforeCall(masm);
+  __ SmiTag(index_);
+  __ Push(object_, index_);
+  __ CallRuntime(Runtime::kStringCharCodeAtRT, 2);
+  __ Mov(result_, x0);
+  call_helper.AfterCall(masm);
+  __ B(&exit_);
+
+  __ Abort(kUnexpectedFallthroughFromCharCodeAtSlowCase);
+}
+
+
+void StringCharFromCodeGenerator::GenerateFast(MacroAssembler* masm) {
+  __ JumpIfNotSmi(code_, &slow_case_);
+  __ Cmp(code_, Smi::FromInt(String::kMaxOneByteCharCode));
+  __ B(hi, &slow_case_);
+
+  __ LoadRoot(result_, Heap::kSingleCharacterStringCacheRootIndex);
+  // At this point code register contains smi tagged one-byte char code.
+  __ Add(result_, result_, Operand::UntagSmiAndScale(code_, kPointerSizeLog2));
+  __ Ldr(result_, FieldMemOperand(result_, FixedArray::kHeaderSize));
+  __ JumpIfRoot(result_, Heap::kUndefinedValueRootIndex, &slow_case_);
+  __ Bind(&exit_);
+}
+
+
+void StringCharFromCodeGenerator::GenerateSlow(
+    MacroAssembler* masm,
+    const RuntimeCallHelper& call_helper) {
+  __ Abort(kUnexpectedFallthroughToCharFromCodeSlowCase);
+
+  __ Bind(&slow_case_);
+  call_helper.BeforeCall(masm);
+  __ Push(code_);
+  __ CallRuntime(Runtime::kCharFromCode, 1);
+  __ Mov(result_, x0);
+  call_helper.AfterCall(masm);
+  __ B(&exit_);
+
+  __ Abort(kUnexpectedFallthroughFromCharFromCodeSlowCase);
+}
+
+
+void CompareICStub::GenerateSmis(MacroAssembler* masm) {
+  // Inputs are in x0 (lhs) and x1 (rhs).
+  DCHECK(state() == CompareICState::SMI);
+  ASM_LOCATION("CompareICStub[Smis]");
+  Label miss;
+  // Bail out (to 'miss') unless both x0 and x1 are smis.
+  __ JumpIfEitherNotSmi(x0, x1, &miss);
+
+  if (GetCondition() == eq) {
+    // For equality we do not care about the sign of the result.
+    __ Sub(x0, x0, x1);
+  } else {
+    // Untag before subtracting to avoid handling overflow.
+    __ SmiUntag(x1);
+    __ Sub(x0, x1, Operand::UntagSmi(x0));
+  }
+  __ Ret();
+
+  __ Bind(&miss);
+  GenerateMiss(masm);
+}
+
+
+void CompareICStub::GenerateNumbers(MacroAssembler* masm) {
+  DCHECK(state() == CompareICState::NUMBER);
+  ASM_LOCATION("CompareICStub[HeapNumbers]");
+
+  Label unordered, maybe_undefined1, maybe_undefined2;
+  Label miss, handle_lhs, values_in_d_regs;
+  Label untag_rhs, untag_lhs;
+
+  Register result = x0;
+  Register rhs = x0;
+  Register lhs = x1;
+  FPRegister rhs_d = d0;
+  FPRegister lhs_d = d1;
+
+  if (left() == CompareICState::SMI) {
+    __ JumpIfNotSmi(lhs, &miss);
+  }
+  if (right() == CompareICState::SMI) {
+    __ JumpIfNotSmi(rhs, &miss);
+  }
+
+  __ SmiUntagToDouble(rhs_d, rhs, kSpeculativeUntag);
+  __ SmiUntagToDouble(lhs_d, lhs, kSpeculativeUntag);
+
+  // Load rhs if it's a heap number.
+  __ JumpIfSmi(rhs, &handle_lhs);
+  __ JumpIfNotHeapNumber(rhs, &maybe_undefined1);
+  __ Ldr(rhs_d, FieldMemOperand(rhs, HeapNumber::kValueOffset));
+
+  // Load lhs if it's a heap number.
+  __ Bind(&handle_lhs);
+  __ JumpIfSmi(lhs, &values_in_d_regs);
+  __ JumpIfNotHeapNumber(lhs, &maybe_undefined2);
+  __ Ldr(lhs_d, FieldMemOperand(lhs, HeapNumber::kValueOffset));
+
+  __ Bind(&values_in_d_regs);
+  __ Fcmp(lhs_d, rhs_d);
+  __ B(vs, &unordered);  // Overflow flag set if either is NaN.
+  STATIC_ASSERT((LESS == -1) && (EQUAL == 0) && (GREATER == 1));
+  __ Cset(result, gt);  // gt => 1, otherwise (lt, eq) => 0 (EQUAL).
+  __ Csinv(result, result, xzr, ge);  // lt => -1, gt => 1, eq => 0.
+  __ Ret();
+
+  __ Bind(&unordered);
+  CompareICStub stub(isolate(), op(), CompareICState::GENERIC,
+                     CompareICState::GENERIC, CompareICState::GENERIC);
+  __ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
+
+  __ Bind(&maybe_undefined1);
+  if (Token::IsOrderedRelationalCompareOp(op())) {
+    __ JumpIfNotRoot(rhs, Heap::kUndefinedValueRootIndex, &miss);
+    __ JumpIfSmi(lhs, &unordered);
+    __ JumpIfNotHeapNumber(lhs, &maybe_undefined2);
+    __ B(&unordered);
+  }
+
+  __ Bind(&maybe_undefined2);
+  if (Token::IsOrderedRelationalCompareOp(op())) {
+    __ JumpIfRoot(lhs, Heap::kUndefinedValueRootIndex, &unordered);
+  }
+
+  __ Bind(&miss);
+  GenerateMiss(masm);
+}
+
+
+void CompareICStub::GenerateInternalizedStrings(MacroAssembler* masm) {
+  DCHECK(state() == CompareICState::INTERNALIZED_STRING);
+  ASM_LOCATION("CompareICStub[InternalizedStrings]");
+  Label miss;
+
+  Register result = x0;
+  Register rhs = x0;
+  Register lhs = x1;
+
+  // Check that both operands are heap objects.
+  __ JumpIfEitherSmi(lhs, rhs, &miss);
+
+  // Check that both operands are internalized strings.
+  Register rhs_map = x10;
+  Register lhs_map = x11;
+  Register rhs_type = x10;
+  Register lhs_type = x11;
+  __ Ldr(lhs_map, FieldMemOperand(lhs, HeapObject::kMapOffset));
+  __ Ldr(rhs_map, FieldMemOperand(rhs, HeapObject::kMapOffset));
+  __ Ldrb(lhs_type, FieldMemOperand(lhs_map, Map::kInstanceTypeOffset));
+  __ Ldrb(rhs_type, FieldMemOperand(rhs_map, Map::kInstanceTypeOffset));
+
+  STATIC_ASSERT((kInternalizedTag == 0) && (kStringTag == 0));
+  __ Orr(x12, lhs_type, rhs_type);
+  __ TestAndBranchIfAnySet(
+      x12, kIsNotStringMask | kIsNotInternalizedMask, &miss);
+
+  // Internalized strings are compared by identity.
+  STATIC_ASSERT(EQUAL == 0);
+  __ Cmp(lhs, rhs);
+  __ Cset(result, ne);
+  __ Ret();
+
+  __ Bind(&miss);
+  GenerateMiss(masm);
+}
+
+
+void CompareICStub::GenerateUniqueNames(MacroAssembler* masm) {
+  DCHECK(state() == CompareICState::UNIQUE_NAME);
+  ASM_LOCATION("CompareICStub[UniqueNames]");
+  DCHECK(GetCondition() == eq);
+  Label miss;
+
+  Register result = x0;
+  Register rhs = x0;
+  Register lhs = x1;
+
+  Register lhs_instance_type = w2;
+  Register rhs_instance_type = w3;
+
+  // Check that both operands are heap objects.
+  __ JumpIfEitherSmi(lhs, rhs, &miss);
+
+  // Check that both operands are unique names. This leaves the instance
+  // types loaded in tmp1 and tmp2.
+  __ Ldr(x10, FieldMemOperand(lhs, HeapObject::kMapOffset));
+  __ Ldr(x11, FieldMemOperand(rhs, HeapObject::kMapOffset));
+  __ Ldrb(lhs_instance_type, FieldMemOperand(x10, Map::kInstanceTypeOffset));
+  __ Ldrb(rhs_instance_type, FieldMemOperand(x11, Map::kInstanceTypeOffset));
+
+  // To avoid a miss, each instance type should be either SYMBOL_TYPE or it
+  // should have kInternalizedTag set.
+  __ JumpIfNotUniqueNameInstanceType(lhs_instance_type, &miss);
+  __ JumpIfNotUniqueNameInstanceType(rhs_instance_type, &miss);
+
+  // Unique names are compared by identity.
+  STATIC_ASSERT(EQUAL == 0);
+  __ Cmp(lhs, rhs);
+  __ Cset(result, ne);
+  __ Ret();
+
+  __ Bind(&miss);
+  GenerateMiss(masm);
+}
+
+
+void CompareICStub::GenerateStrings(MacroAssembler* masm) {
+  DCHECK(state() == CompareICState::STRING);
+  ASM_LOCATION("CompareICStub[Strings]");
+
+  Label miss;
+
+  bool equality = Token::IsEqualityOp(op());
+
+  Register result = x0;
+  Register rhs = x0;
+  Register lhs = x1;
+
+  // Check that both operands are heap objects.
+  __ JumpIfEitherSmi(rhs, lhs, &miss);
+
+  // Check that both operands are strings.
+  Register rhs_map = x10;
+  Register lhs_map = x11;
+  Register rhs_type = x10;
+  Register lhs_type = x11;
+  __ Ldr(lhs_map, FieldMemOperand(lhs, HeapObject::kMapOffset));
+  __ Ldr(rhs_map, FieldMemOperand(rhs, HeapObject::kMapOffset));
+  __ Ldrb(lhs_type, FieldMemOperand(lhs_map, Map::kInstanceTypeOffset));
+  __ Ldrb(rhs_type, FieldMemOperand(rhs_map, Map::kInstanceTypeOffset));
+  STATIC_ASSERT(kNotStringTag != 0);
+  __ Orr(x12, lhs_type, rhs_type);
+  __ Tbnz(x12, MaskToBit(kIsNotStringMask), &miss);
+
+  // Fast check for identical strings.
+  Label not_equal;
+  __ Cmp(lhs, rhs);
+  __ B(ne, &not_equal);
+  __ Mov(result, EQUAL);
+  __ Ret();
+
+  __ Bind(&not_equal);
+  // Handle not identical strings
+
+  // Check that both strings are internalized strings. If they are, we're done
+  // because we already know they are not identical. We know they are both
+  // strings.
+  if (equality) {
+    DCHECK(GetCondition() == eq);
+    STATIC_ASSERT(kInternalizedTag == 0);
+    Label not_internalized_strings;
+    __ Orr(x12, lhs_type, rhs_type);
+    __ TestAndBranchIfAnySet(
+        x12, kIsNotInternalizedMask, &not_internalized_strings);
+    // Result is in rhs (x0), and not EQUAL, as rhs is not a smi.
+    __ Ret();
+    __ Bind(&not_internalized_strings);
+  }
+
+  // Check that both strings are sequential one-byte.
+  Label runtime;
+  __ JumpIfBothInstanceTypesAreNotSequentialOneByte(lhs_type, rhs_type, x12,
+                                                    x13, &runtime);
+
+  // Compare flat one-byte strings. Returns when done.
+  if (equality) {
+    StringHelper::GenerateFlatOneByteStringEquals(masm, lhs, rhs, x10, x11,
+                                                  x12);
+  } else {
+    StringHelper::GenerateCompareFlatOneByteStrings(masm, lhs, rhs, x10, x11,
+                                                    x12, x13);
+  }
+
+  // Handle more complex cases in runtime.
+  __ Bind(&runtime);
+  __ Push(lhs, rhs);
+  if (equality) {
+    __ TailCallRuntime(Runtime::kStringEquals, 2, 1);
+  } else {
+    __ TailCallRuntime(Runtime::kStringCompare, 2, 1);
+  }
+
+  __ Bind(&miss);
+  GenerateMiss(masm);
+}
+
+
+void CompareICStub::GenerateObjects(MacroAssembler* masm) {
+  DCHECK(state() == CompareICState::OBJECT);
+  ASM_LOCATION("CompareICStub[Objects]");
+
+  Label miss;
+
+  Register result = x0;
+  Register rhs = x0;
+  Register lhs = x1;
+
+  __ JumpIfEitherSmi(rhs, lhs, &miss);
+
+  __ JumpIfNotObjectType(rhs, x10, x10, JS_OBJECT_TYPE, &miss);
+  __ JumpIfNotObjectType(lhs, x10, x10, JS_OBJECT_TYPE, &miss);
+
+  DCHECK(GetCondition() == eq);
+  __ Sub(result, rhs, lhs);
+  __ Ret();
+
+  __ Bind(&miss);
+  GenerateMiss(masm);
+}
+
+
+void CompareICStub::GenerateKnownObjects(MacroAssembler* masm) {
+  ASM_LOCATION("CompareICStub[KnownObjects]");
+
+  Label miss;
+
+  Register result = x0;
+  Register rhs = x0;
+  Register lhs = x1;
+
+  __ JumpIfEitherSmi(rhs, lhs, &miss);
+
+  Register rhs_map = x10;
+  Register lhs_map = x11;
+  __ Ldr(rhs_map, FieldMemOperand(rhs, HeapObject::kMapOffset));
+  __ Ldr(lhs_map, FieldMemOperand(lhs, HeapObject::kMapOffset));
+  __ Cmp(rhs_map, Operand(known_map_));
+  __ B(ne, &miss);
+  __ Cmp(lhs_map, Operand(known_map_));
+  __ B(ne, &miss);
+
+  __ Sub(result, rhs, lhs);
+  __ Ret();
+
+  __ Bind(&miss);
+  GenerateMiss(masm);
+}
+
+
+// This method handles the case where a compare stub had the wrong
+// implementation. It calls a miss handler, which re-writes the stub. All other
+// CompareICStub::Generate* methods should fall back into this one if their
+// operands were not the expected types.
+void CompareICStub::GenerateMiss(MacroAssembler* masm) {
+  ASM_LOCATION("CompareICStub[Miss]");
+
+  Register stub_entry = x11;
+  {
+    ExternalReference miss =
+      ExternalReference(IC_Utility(IC::kCompareIC_Miss), isolate());
+
+    FrameScope scope(masm, StackFrame::INTERNAL);
+    Register op = x10;
+    Register left = x1;
+    Register right = x0;
+    // Preserve some caller-saved registers.
+    __ Push(x1, x0, lr);
+    // Push the arguments.
+    __ Mov(op, Smi::FromInt(this->op()));
+    __ Push(left, right, op);
+
+    // Call the miss handler. This also pops the arguments.
+    __ CallExternalReference(miss, 3);
+
+    // Compute the entry point of the rewritten stub.
+    __ Add(stub_entry, x0, Code::kHeaderSize - kHeapObjectTag);
+    // Restore caller-saved registers.
+    __ Pop(lr, x0, x1);
+  }
+
+  // Tail-call to the new stub.
+  __ Jump(stub_entry);
+}
+
+
+void SubStringStub::Generate(MacroAssembler* masm) {
+  ASM_LOCATION("SubStringStub::Generate");
+  Label runtime;
+
+  // Stack frame on entry.
+  //  lr: return address
+  //  jssp[0]:  substring "to" offset
+  //  jssp[8]:  substring "from" offset
+  //  jssp[16]: pointer to string object
+
+  // This stub is called from the native-call %_SubString(...), so
+  // nothing can be assumed about the arguments. It is tested that:
+  //  "string" is a sequential string,
+  //  both "from" and "to" are smis, and
+  //  0 <= from <= to <= string.length (in debug mode.)
+  // If any of these assumptions fail, we call the runtime system.
+
+  static const int kToOffset = 0 * kPointerSize;
+  static const int kFromOffset = 1 * kPointerSize;
+  static const int kStringOffset = 2 * kPointerSize;
+
+  Register to = x0;
+  Register from = x15;
+  Register input_string = x10;
+  Register input_length = x11;
+  Register input_type = x12;
+  Register result_string = x0;
+  Register result_length = x1;
+  Register temp = x3;
+
+  __ Peek(to, kToOffset);
+  __ Peek(from, kFromOffset);
+
+  // Check that both from and to are smis. If not, jump to runtime.
+  __ JumpIfEitherNotSmi(from, to, &runtime);
+  __ SmiUntag(from);
+  __ SmiUntag(to);
+
+  // Calculate difference between from and to. If to < from, branch to runtime.
+  __ Subs(result_length, to, from);
+  __ B(mi, &runtime);
+
+  // Check from is positive.
+  __ Tbnz(from, kWSignBit, &runtime);
+
+  // Make sure first argument is a string.
+  __ Peek(input_string, kStringOffset);
+  __ JumpIfSmi(input_string, &runtime);
+  __ IsObjectJSStringType(input_string, input_type, &runtime);
+
+  Label single_char;
+  __ Cmp(result_length, 1);
+  __ B(eq, &single_char);
+
+  // Short-cut for the case of trivial substring.
+  Label return_x0;
+  __ Ldrsw(input_length,
+           UntagSmiFieldMemOperand(input_string, String::kLengthOffset));
+
+  __ Cmp(result_length, input_length);
+  __ CmovX(x0, input_string, eq);
+  // Return original string.
+  __ B(eq, &return_x0);
+
+  // Longer than original string's length or negative: unsafe arguments.
+  __ B(hi, &runtime);
+
+  // Shorter than original string's length: an actual substring.
+
+  //   x0   to               substring end character offset
+  //   x1   result_length    length of substring result
+  //   x10  input_string     pointer to input string object
+  //   x10  unpacked_string  pointer to unpacked string object
+  //   x11  input_length     length of input string
+  //   x12  input_type       instance type of input string
+  //   x15  from             substring start character offset
+
+  // Deal with different string types: update the index if necessary and put
+  // the underlying string into register unpacked_string.
+  Label underlying_unpacked, sliced_string, seq_or_external_string;
+  Label update_instance_type;
+  // If the string is not indirect, it can only be sequential or external.
+  STATIC_ASSERT(kIsIndirectStringMask == (kSlicedStringTag & kConsStringTag));
+  STATIC_ASSERT(kIsIndirectStringMask != 0);
+
+  // Test for string types, and branch/fall through to appropriate unpacking
+  // code.
+  __ Tst(input_type, kIsIndirectStringMask);
+  __ B(eq, &seq_or_external_string);
+  __ Tst(input_type, kSlicedNotConsMask);
+  __ B(ne, &sliced_string);
+
+  Register unpacked_string = input_string;
+
+  // Cons string. Check whether it is flat, then fetch first part.
+  __ Ldr(temp, FieldMemOperand(input_string, ConsString::kSecondOffset));
+  __ JumpIfNotRoot(temp, Heap::kempty_stringRootIndex, &runtime);
+  __ Ldr(unpacked_string,
+         FieldMemOperand(input_string, ConsString::kFirstOffset));
+  __ B(&update_instance_type);
+
+  __ Bind(&sliced_string);
+  // Sliced string. Fetch parent and correct start index by offset.
+  __ Ldrsw(temp,
+           UntagSmiFieldMemOperand(input_string, SlicedString::kOffsetOffset));
+  __ Add(from, from, temp);
+  __ Ldr(unpacked_string,
+         FieldMemOperand(input_string, SlicedString::kParentOffset));
+
+  __ Bind(&update_instance_type);
+  __ Ldr(temp, FieldMemOperand(unpacked_string, HeapObject::kMapOffset));
+  __ Ldrb(input_type, FieldMemOperand(temp, Map::kInstanceTypeOffset));
+  // Now control must go to &underlying_unpacked. Since the no code is generated
+  // before then we fall through instead of generating a useless branch.
+
+  __ Bind(&seq_or_external_string);
+  // Sequential or external string. Registers unpacked_string and input_string
+  // alias, so there's nothing to do here.
+  // Note that if code is added here, the above code must be updated.
+
+  //   x0   result_string    pointer to result string object (uninit)
+  //   x1   result_length    length of substring result
+  //   x10  unpacked_string  pointer to unpacked string object
+  //   x11  input_length     length of input string
+  //   x12  input_type       instance type of input string
+  //   x15  from             substring start character offset
+  __ Bind(&underlying_unpacked);
+
+  if (FLAG_string_slices) {
+    Label copy_routine;
+    __ Cmp(result_length, SlicedString::kMinLength);
+    // Short slice. Copy instead of slicing.
+    __ B(lt, &copy_routine);
+    // Allocate new sliced string. At this point we do not reload the instance
+    // type including the string encoding because we simply rely on the info
+    // provided by the original string. It does not matter if the original
+    // string's encoding is wrong because we always have to recheck encoding of
+    // the newly created string's parent anyway due to externalized strings.
+    Label two_byte_slice, set_slice_header;
+    STATIC_ASSERT((kStringEncodingMask & kOneByteStringTag) != 0);
+    STATIC_ASSERT((kStringEncodingMask & kTwoByteStringTag) == 0);
+    __ Tbz(input_type, MaskToBit(kStringEncodingMask), &two_byte_slice);
+    __ AllocateOneByteSlicedString(result_string, result_length, x3, x4,
+                                   &runtime);
+    __ B(&set_slice_header);
+
+    __ Bind(&two_byte_slice);
+    __ AllocateTwoByteSlicedString(result_string, result_length, x3, x4,
+                                   &runtime);
+
+    __ Bind(&set_slice_header);
+    __ SmiTag(from);
+    __ Str(from, FieldMemOperand(result_string, SlicedString::kOffsetOffset));
+    __ Str(unpacked_string,
+           FieldMemOperand(result_string, SlicedString::kParentOffset));
+    __ B(&return_x0);
+
+    __ Bind(&copy_routine);
+  }
+
+  //   x0   result_string    pointer to result string object (uninit)
+  //   x1   result_length    length of substring result
+  //   x10  unpacked_string  pointer to unpacked string object
+  //   x11  input_length     length of input string
+  //   x12  input_type       instance type of input string
+  //   x13  unpacked_char0   pointer to first char of unpacked string (uninit)
+  //   x13  substring_char0  pointer to first char of substring (uninit)
+  //   x14  result_char0     pointer to first char of result (uninit)
+  //   x15  from             substring start character offset
+  Register unpacked_char0 = x13;
+  Register substring_char0 = x13;
+  Register result_char0 = x14;
+  Label two_byte_sequential, sequential_string, allocate_result;
+  STATIC_ASSERT(kExternalStringTag != 0);
+  STATIC_ASSERT(kSeqStringTag == 0);
+
+  __ Tst(input_type, kExternalStringTag);
+  __ B(eq, &sequential_string);
+
+  __ Tst(input_type, kShortExternalStringTag);
+  __ B(ne, &runtime);
+  __ Ldr(unpacked_char0,
+         FieldMemOperand(unpacked_string, ExternalString::kResourceDataOffset));
+  // unpacked_char0 points to the first character of the underlying string.
+  __ B(&allocate_result);
+
+  __ Bind(&sequential_string);
+  // Locate first character of underlying subject string.
+  STATIC_ASSERT(SeqTwoByteString::kHeaderSize == SeqOneByteString::kHeaderSize);
+  __ Add(unpacked_char0, unpacked_string,
+         SeqOneByteString::kHeaderSize - kHeapObjectTag);
+
+  __ Bind(&allocate_result);
+  // Sequential one-byte string. Allocate the result.
+  STATIC_ASSERT((kOneByteStringTag & kStringEncodingMask) != 0);
+  __ Tbz(input_type, MaskToBit(kStringEncodingMask), &two_byte_sequential);
+
+  // Allocate and copy the resulting one-byte string.
+  __ AllocateOneByteString(result_string, result_length, x3, x4, x5, &runtime);
+
+  // Locate first character of substring to copy.
+  __ Add(substring_char0, unpacked_char0, from);
+
+  // Locate first character of result.
+  __ Add(result_char0, result_string,
+         SeqOneByteString::kHeaderSize - kHeapObjectTag);
+
+  STATIC_ASSERT((SeqOneByteString::kHeaderSize & kObjectAlignmentMask) == 0);
+  __ CopyBytes(result_char0, substring_char0, result_length, x3, kCopyLong);
+  __ B(&return_x0);
+
+  // Allocate and copy the resulting two-byte string.
+  __ Bind(&two_byte_sequential);
+  __ AllocateTwoByteString(result_string, result_length, x3, x4, x5, &runtime);
+
+  // Locate first character of substring to copy.
+  __ Add(substring_char0, unpacked_char0, Operand(from, LSL, 1));
+
+  // Locate first character of result.
+  __ Add(result_char0, result_string,
+         SeqTwoByteString::kHeaderSize - kHeapObjectTag);
+
+  STATIC_ASSERT((SeqTwoByteString::kHeaderSize & kObjectAlignmentMask) == 0);
+  __ Add(result_length, result_length, result_length);
+  __ CopyBytes(result_char0, substring_char0, result_length, x3, kCopyLong);
+
+  __ Bind(&return_x0);
+  Counters* counters = isolate()->counters();
+  __ IncrementCounter(counters->sub_string_native(), 1, x3, x4);
+  __ Drop(3);
+  __ Ret();
+
+  __ Bind(&runtime);
+  __ TailCallRuntime(Runtime::kSubString, 3, 1);
+
+  __ bind(&single_char);
+  // x1: result_length
+  // x10: input_string
+  // x12: input_type
+  // x15: from (untagged)
+  __ SmiTag(from);
+  StringCharAtGenerator generator(
+      input_string, from, result_length, x0,
+      &runtime, &runtime, &runtime, STRING_INDEX_IS_NUMBER);
+  generator.GenerateFast(masm);
+  __ Drop(3);
+  __ Ret();
+  generator.SkipSlow(masm, &runtime);
+}
+
+
+void StringHelper::GenerateFlatOneByteStringEquals(
+    MacroAssembler* masm, Register left, Register right, Register scratch1,
+    Register scratch2, Register scratch3) {
+  DCHECK(!AreAliased(left, right, scratch1, scratch2, scratch3));
+  Register result = x0;
+  Register left_length = scratch1;
+  Register right_length = scratch2;
+
+  // Compare lengths. If lengths differ, strings can't be equal. Lengths are
+  // smis, and don't need to be untagged.
+  Label strings_not_equal, check_zero_length;
+  __ Ldr(left_length, FieldMemOperand(left, String::kLengthOffset));
+  __ Ldr(right_length, FieldMemOperand(right, String::kLengthOffset));
+  __ Cmp(left_length, right_length);
+  __ B(eq, &check_zero_length);
+
+  __ Bind(&strings_not_equal);
+  __ Mov(result, Smi::FromInt(NOT_EQUAL));
+  __ Ret();
+
+  // Check if the length is zero. If so, the strings must be equal (and empty.)
+  Label compare_chars;
+  __ Bind(&check_zero_length);
+  STATIC_ASSERT(kSmiTag == 0);
+  __ Cbnz(left_length, &compare_chars);
+  __ Mov(result, Smi::FromInt(EQUAL));
+  __ Ret();
+
+  // Compare characters. Falls through if all characters are equal.
+  __ Bind(&compare_chars);
+  GenerateOneByteCharsCompareLoop(masm, left, right, left_length, scratch2,
+                                  scratch3, &strings_not_equal);
+
+  // Characters in strings are equal.
+  __ Mov(result, Smi::FromInt(EQUAL));
+  __ Ret();
+}
+
+
+void StringHelper::GenerateCompareFlatOneByteStrings(
+    MacroAssembler* masm, Register left, Register right, Register scratch1,
+    Register scratch2, Register scratch3, Register scratch4) {
+  DCHECK(!AreAliased(left, right, scratch1, scratch2, scratch3, scratch4));
+  Label result_not_equal, compare_lengths;
+
+  // Find minimum length and length difference.
+  Register length_delta = scratch3;
+  __ Ldr(scratch1, FieldMemOperand(left, String::kLengthOffset));
+  __ Ldr(scratch2, FieldMemOperand(right, String::kLengthOffset));
+  __ Subs(length_delta, scratch1, scratch2);
+
+  Register min_length = scratch1;
+  __ Csel(min_length, scratch2, scratch1, gt);
+  __ Cbz(min_length, &compare_lengths);
+
+  // Compare loop.
+  GenerateOneByteCharsCompareLoop(masm, left, right, min_length, scratch2,
+                                  scratch4, &result_not_equal);
+
+  // Compare lengths - strings up to min-length are equal.
+  __ Bind(&compare_lengths);
+
+  DCHECK(Smi::FromInt(EQUAL) == static_cast<Smi*>(0));
+
+  // Use length_delta as result if it's zero.
+  Register result = x0;
+  __ Subs(result, length_delta, 0);
+
+  __ Bind(&result_not_equal);
+  Register greater = x10;
+  Register less = x11;
+  __ Mov(greater, Smi::FromInt(GREATER));
+  __ Mov(less, Smi::FromInt(LESS));
+  __ CmovX(result, greater, gt);
+  __ CmovX(result, less, lt);
+  __ Ret();
+}
+
+
+void StringHelper::GenerateOneByteCharsCompareLoop(
+    MacroAssembler* masm, Register left, Register right, Register length,
+    Register scratch1, Register scratch2, Label* chars_not_equal) {
+  DCHECK(!AreAliased(left, right, length, scratch1, scratch2));
+
+  // Change index to run from -length to -1 by adding length to string
+  // start. This means that loop ends when index reaches zero, which
+  // doesn't need an additional compare.
+  __ SmiUntag(length);
+  __ Add(scratch1, length, SeqOneByteString::kHeaderSize - kHeapObjectTag);
+  __ Add(left, left, scratch1);
+  __ Add(right, right, scratch1);
+
+  Register index = length;
+  __ Neg(index, length);  // index = -length;
+
+  // Compare loop
+  Label loop;
+  __ Bind(&loop);
+  __ Ldrb(scratch1, MemOperand(left, index));
+  __ Ldrb(scratch2, MemOperand(right, index));
+  __ Cmp(scratch1, scratch2);
+  __ B(ne, chars_not_equal);
+  __ Add(index, index, 1);
+  __ Cbnz(index, &loop);
+}
+
+
+void StringCompareStub::Generate(MacroAssembler* masm) {
+  Label runtime;
+
+  Counters* counters = isolate()->counters();
+
+  // Stack frame on entry.
+  //  sp[0]: right string
+  //  sp[8]: left string
+  Register right = x10;
+  Register left = x11;
+  Register result = x0;
+  __ Pop(right, left);
+
+  Label not_same;
+  __ Subs(result, right, left);
+  __ B(ne, &not_same);
+  STATIC_ASSERT(EQUAL == 0);
+  __ IncrementCounter(counters->string_compare_native(), 1, x3, x4);
+  __ Ret();
+
+  __ Bind(&not_same);
+
+  // Check that both objects are sequential one-byte strings.
+  __ JumpIfEitherIsNotSequentialOneByteStrings(left, right, x12, x13, &runtime);
+
+  // Compare flat one-byte strings natively. Remove arguments from stack first,
+  // as this function will generate a return.
+  __ IncrementCounter(counters->string_compare_native(), 1, x3, x4);
+  StringHelper::GenerateCompareFlatOneByteStrings(masm, left, right, x12, x13,
+                                                  x14, x15);
+
+  __ Bind(&runtime);
+
+  // Push arguments back on to the stack.
+  //  sp[0] = right string
+  //  sp[8] = left string.
+  __ Push(left, right);
+
+  // Call the runtime.
+  // Returns -1 (less), 0 (equal), or 1 (greater) tagged as a small integer.
+  __ TailCallRuntime(Runtime::kStringCompare, 2, 1);
+}
+
+
+void BinaryOpICWithAllocationSiteStub::Generate(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- x1    : left
+  //  -- x0    : right
+  //  -- lr    : return address
+  // -----------------------------------
+
+  // Load x2 with the allocation site.  We stick an undefined dummy value here
+  // and replace it with the real allocation site later when we instantiate this
+  // stub in BinaryOpICWithAllocationSiteStub::GetCodeCopyFromTemplate().
+  __ LoadObject(x2, handle(isolate()->heap()->undefined_value()));
+
+  // Make sure that we actually patched the allocation site.
+  if (FLAG_debug_code) {
+    __ AssertNotSmi(x2, kExpectedAllocationSite);
+    __ Ldr(x10, FieldMemOperand(x2, HeapObject::kMapOffset));
+    __ AssertRegisterIsRoot(x10, Heap::kAllocationSiteMapRootIndex,
+                            kExpectedAllocationSite);
+  }
+
+  // Tail call into the stub that handles binary operations with allocation
+  // sites.
+  BinaryOpWithAllocationSiteStub stub(isolate(), state());
+  __ TailCallStub(&stub);
+}
+
+
+void RecordWriteStub::GenerateIncremental(MacroAssembler* masm, Mode mode) {
+  // We need some extra registers for this stub, they have been allocated
+  // but we need to save them before using them.
+  regs_.Save(masm);
+
+  if (remembered_set_action() == EMIT_REMEMBERED_SET) {
+    Label dont_need_remembered_set;
+
+    Register val = regs_.scratch0();
+    __ Ldr(val, MemOperand(regs_.address()));
+    __ JumpIfNotInNewSpace(val, &dont_need_remembered_set);
+
+    __ CheckPageFlagSet(regs_.object(), val, 1 << MemoryChunk::SCAN_ON_SCAVENGE,
+                        &dont_need_remembered_set);
+
+    // First notify the incremental marker if necessary, then update the
+    // remembered set.
+    CheckNeedsToInformIncrementalMarker(
+        masm, kUpdateRememberedSetOnNoNeedToInformIncrementalMarker, mode);
+    InformIncrementalMarker(masm);
+    regs_.Restore(masm);  // Restore the extra scratch registers we used.
+
+    __ RememberedSetHelper(object(), address(),
+                           value(),  // scratch1
+                           save_fp_regs_mode(), MacroAssembler::kReturnAtEnd);
+
+    __ Bind(&dont_need_remembered_set);
+  }
+
+  CheckNeedsToInformIncrementalMarker(
+      masm, kReturnOnNoNeedToInformIncrementalMarker, mode);
+  InformIncrementalMarker(masm);
+  regs_.Restore(masm);  // Restore the extra scratch registers we used.
+  __ Ret();
+}
+
+
+void RecordWriteStub::InformIncrementalMarker(MacroAssembler* masm) {
+  regs_.SaveCallerSaveRegisters(masm, save_fp_regs_mode());
+  Register address =
+    x0.Is(regs_.address()) ? regs_.scratch0() : regs_.address();
+  DCHECK(!address.Is(regs_.object()));
+  DCHECK(!address.Is(x0));
+  __ Mov(address, regs_.address());
+  __ Mov(x0, regs_.object());
+  __ Mov(x1, address);
+  __ Mov(x2, ExternalReference::isolate_address(isolate()));
+
+  AllowExternalCallThatCantCauseGC scope(masm);
+  ExternalReference function =
+      ExternalReference::incremental_marking_record_write_function(
+          isolate());
+  __ CallCFunction(function, 3, 0);
+
+  regs_.RestoreCallerSaveRegisters(masm, save_fp_regs_mode());
+}
+
+
+void RecordWriteStub::CheckNeedsToInformIncrementalMarker(
+    MacroAssembler* masm,
+    OnNoNeedToInformIncrementalMarker on_no_need,
+    Mode mode) {
+  Label on_black;
+  Label need_incremental;
+  Label need_incremental_pop_scratch;
+
+  Register mem_chunk = regs_.scratch0();
+  Register counter = regs_.scratch1();
+  __ Bic(mem_chunk, regs_.object(), Page::kPageAlignmentMask);
+  __ Ldr(counter,
+         MemOperand(mem_chunk, MemoryChunk::kWriteBarrierCounterOffset));
+  __ Subs(counter, counter, 1);
+  __ Str(counter,
+         MemOperand(mem_chunk, MemoryChunk::kWriteBarrierCounterOffset));
+  __ B(mi, &need_incremental);
+
+  // If the object is not black we don't have to inform the incremental marker.
+  __ JumpIfBlack(regs_.object(), regs_.scratch0(), regs_.scratch1(), &on_black);
+
+  regs_.Restore(masm);  // Restore the extra scratch registers we used.
+  if (on_no_need == kUpdateRememberedSetOnNoNeedToInformIncrementalMarker) {
+    __ RememberedSetHelper(object(), address(),
+                           value(),  // scratch1
+                           save_fp_regs_mode(), MacroAssembler::kReturnAtEnd);
+  } else {
+    __ Ret();
+  }
+
+  __ Bind(&on_black);
+  // Get the value from the slot.
+  Register val = regs_.scratch0();
+  __ Ldr(val, MemOperand(regs_.address()));
+
+  if (mode == INCREMENTAL_COMPACTION) {
+    Label ensure_not_white;
+
+    __ CheckPageFlagClear(val, regs_.scratch1(),
+                          MemoryChunk::kEvacuationCandidateMask,
+                          &ensure_not_white);
+
+    __ CheckPageFlagClear(regs_.object(),
+                          regs_.scratch1(),
+                          MemoryChunk::kSkipEvacuationSlotsRecordingMask,
+                          &need_incremental);
+
+    __ Bind(&ensure_not_white);
+  }
+
+  // We need extra registers for this, so we push the object and the address
+  // register temporarily.
+  __ Push(regs_.address(), regs_.object());
+  __ EnsureNotWhite(val,
+                    regs_.scratch1(),  // Scratch.
+                    regs_.object(),    // Scratch.
+                    regs_.address(),   // Scratch.
+                    regs_.scratch2(),  // Scratch.
+                    &need_incremental_pop_scratch);
+  __ Pop(regs_.object(), regs_.address());
+
+  regs_.Restore(masm);  // Restore the extra scratch registers we used.
+  if (on_no_need == kUpdateRememberedSetOnNoNeedToInformIncrementalMarker) {
+    __ RememberedSetHelper(object(), address(),
+                           value(),  // scratch1
+                           save_fp_regs_mode(), MacroAssembler::kReturnAtEnd);
+  } else {
+    __ Ret();
+  }
+
+  __ Bind(&need_incremental_pop_scratch);
+  __ Pop(regs_.object(), regs_.address());
+
+  __ Bind(&need_incremental);
+  // Fall through when we need to inform the incremental marker.
+}
+
+
+void RecordWriteStub::Generate(MacroAssembler* masm) {
+  Label skip_to_incremental_noncompacting;
+  Label skip_to_incremental_compacting;
+
+  // We patch these two first instructions back and forth between a nop and
+  // real branch when we start and stop incremental heap marking.
+  // Initially the stub is expected to be in STORE_BUFFER_ONLY mode, so 2 nops
+  // are generated.
+  // See RecordWriteStub::Patch for details.
+  {
+    InstructionAccurateScope scope(masm, 2);
+    __ adr(xzr, &skip_to_incremental_noncompacting);
+    __ adr(xzr, &skip_to_incremental_compacting);
+  }
+
+  if (remembered_set_action() == EMIT_REMEMBERED_SET) {
+    __ RememberedSetHelper(object(), address(),
+                           value(),  // scratch1
+                           save_fp_regs_mode(), MacroAssembler::kReturnAtEnd);
+  }
+  __ Ret();
+
+  __ Bind(&skip_to_incremental_noncompacting);
+  GenerateIncremental(masm, INCREMENTAL);
+
+  __ Bind(&skip_to_incremental_compacting);
+  GenerateIncremental(masm, INCREMENTAL_COMPACTION);
+}
+
+
+void StoreArrayLiteralElementStub::Generate(MacroAssembler* masm) {
+  // x0     value            element value to store
+  // x3     index_smi        element index as smi
+  // sp[0]  array_index_smi  array literal index in function as smi
+  // sp[1]  array            array literal
+
+  Register value = x0;
+  Register index_smi = x3;
+
+  Register array = x1;
+  Register array_map = x2;
+  Register array_index_smi = x4;
+  __ PeekPair(array_index_smi, array, 0);
+  __ Ldr(array_map, FieldMemOperand(array, JSObject::kMapOffset));
+
+  Label double_elements, smi_element, fast_elements, slow_elements;
+  Register bitfield2 = x10;
+  __ Ldrb(bitfield2, FieldMemOperand(array_map, Map::kBitField2Offset));
+
+  // Jump if array's ElementsKind is not FAST*_SMI_ELEMENTS, FAST_ELEMENTS or
+  // FAST_HOLEY_ELEMENTS.
+  STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
+  STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
+  STATIC_ASSERT(FAST_ELEMENTS == 2);
+  STATIC_ASSERT(FAST_HOLEY_ELEMENTS == 3);
+  __ Cmp(bitfield2, Map::kMaximumBitField2FastHoleyElementValue);
+  __ B(hi, &double_elements);
+
+  __ JumpIfSmi(value, &smi_element);
+
+  // Jump if array's ElementsKind is not FAST_ELEMENTS or FAST_HOLEY_ELEMENTS.
+  __ Tbnz(bitfield2, MaskToBit(FAST_ELEMENTS << Map::ElementsKindBits::kShift),
+          &fast_elements);
+
+  // Store into the array literal requires an elements transition. Call into
+  // the runtime.
+  __ Bind(&slow_elements);
+  __ Push(array, index_smi, value);
+  __ Ldr(x10, MemOperand(fp, JavaScriptFrameConstants::kFunctionOffset));
+  __ Ldr(x11, FieldMemOperand(x10, JSFunction::kLiteralsOffset));
+  __ Push(x11, array_index_smi);
+  __ TailCallRuntime(Runtime::kStoreArrayLiteralElement, 5, 1);
+
+  // Array literal has ElementsKind of FAST_*_ELEMENTS and value is an object.
+  __ Bind(&fast_elements);
+  __ Ldr(x10, FieldMemOperand(array, JSObject::kElementsOffset));
+  __ Add(x11, x10, Operand::UntagSmiAndScale(index_smi, kPointerSizeLog2));
+  __ Add(x11, x11, FixedArray::kHeaderSize - kHeapObjectTag);
+  __ Str(value, MemOperand(x11));
+  // Update the write barrier for the array store.
+  __ RecordWrite(x10, x11, value, kLRHasNotBeenSaved, kDontSaveFPRegs,
+                 EMIT_REMEMBERED_SET, OMIT_SMI_CHECK);
+  __ Ret();
+
+  // Array literal has ElementsKind of FAST_*_SMI_ELEMENTS or FAST_*_ELEMENTS,
+  // and value is Smi.
+  __ Bind(&smi_element);
+  __ Ldr(x10, FieldMemOperand(array, JSObject::kElementsOffset));
+  __ Add(x11, x10, Operand::UntagSmiAndScale(index_smi, kPointerSizeLog2));
+  __ Str(value, FieldMemOperand(x11, FixedArray::kHeaderSize));
+  __ Ret();
+
+  __ Bind(&double_elements);
+  __ Ldr(x10, FieldMemOperand(array, JSObject::kElementsOffset));
+  __ StoreNumberToDoubleElements(value, index_smi, x10, x11, d0,
+                                 &slow_elements);
+  __ Ret();
+}
+
+
+void StubFailureTrampolineStub::Generate(MacroAssembler* masm) {
+  CEntryStub ces(isolate(), 1, kSaveFPRegs);
+  __ Call(ces.GetCode(), RelocInfo::CODE_TARGET);
+  int parameter_count_offset =
+      StubFailureTrampolineFrame::kCallerStackParameterCountFrameOffset;
+  __ Ldr(x1, MemOperand(fp, parameter_count_offset));
+  if (function_mode() == JS_FUNCTION_STUB_MODE) {
+    __ Add(x1, x1, 1);
+  }
+  masm->LeaveFrame(StackFrame::STUB_FAILURE_TRAMPOLINE);
+  __ Drop(x1);
+  // Return to IC Miss stub, continuation still on stack.
+  __ Ret();
+}
+
+
+void LoadICTrampolineStub::Generate(MacroAssembler* masm) {
+  EmitLoadTypeFeedbackVector(masm, VectorLoadICDescriptor::VectorRegister());
+  VectorLoadStub stub(isolate(), state());
+  __ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
+}
+
+
+void KeyedLoadICTrampolineStub::Generate(MacroAssembler* masm) {
+  EmitLoadTypeFeedbackVector(masm, VectorLoadICDescriptor::VectorRegister());
+  VectorKeyedLoadStub stub(isolate());
+  __ Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
+}
+
+
+static unsigned int GetProfileEntryHookCallSize(MacroAssembler* masm) {
+  // The entry hook is a "BumpSystemStackPointer" instruction (sub),
+  // followed by a "Push lr" instruction, followed by a call.
+  unsigned int size =
+      Assembler::kCallSizeWithRelocation + (2 * kInstructionSize);
+  if (CpuFeatures::IsSupported(ALWAYS_ALIGN_CSP)) {
+    // If ALWAYS_ALIGN_CSP then there will be an extra bic instruction in
+    // "BumpSystemStackPointer".
+    size += kInstructionSize;
+  }
+  return size;
+}
+
+
+void ProfileEntryHookStub::MaybeCallEntryHook(MacroAssembler* masm) {
+  if (masm->isolate()->function_entry_hook() != NULL) {
+    ProfileEntryHookStub stub(masm->isolate());
+    Assembler::BlockConstPoolScope no_const_pools(masm);
+    DontEmitDebugCodeScope no_debug_code(masm);
+    Label entry_hook_call_start;
+    __ Bind(&entry_hook_call_start);
+    __ Push(lr);
+    __ CallStub(&stub);
+    DCHECK(masm->SizeOfCodeGeneratedSince(&entry_hook_call_start) ==
+           GetProfileEntryHookCallSize(masm));
+
+    __ Pop(lr);
+  }
+}
+
+
+void ProfileEntryHookStub::Generate(MacroAssembler* masm) {
+  MacroAssembler::NoUseRealAbortsScope no_use_real_aborts(masm);
+
+  // Save all kCallerSaved registers (including lr), since this can be called
+  // from anywhere.
+  // TODO(jbramley): What about FP registers?
+  __ PushCPURegList(kCallerSaved);
+  DCHECK(kCallerSaved.IncludesAliasOf(lr));
+  const int kNumSavedRegs = kCallerSaved.Count();
+
+  // Compute the function's address as the first argument.
+  __ Sub(x0, lr, GetProfileEntryHookCallSize(masm));
+
+#if V8_HOST_ARCH_ARM64
+  uintptr_t entry_hook =
+      reinterpret_cast<uintptr_t>(isolate()->function_entry_hook());
+  __ Mov(x10, entry_hook);
+#else
+  // Under the simulator we need to indirect the entry hook through a trampoline
+  // function at a known address.
+  ApiFunction dispatcher(FUNCTION_ADDR(EntryHookTrampoline));
+  __ Mov(x10, Operand(ExternalReference(&dispatcher,
+                                        ExternalReference::BUILTIN_CALL,
+                                        isolate())));
+  // It additionally takes an isolate as a third parameter
+  __ Mov(x2, ExternalReference::isolate_address(isolate()));
+#endif
+
+  // The caller's return address is above the saved temporaries.
+  // Grab its location for the second argument to the hook.
+  __ Add(x1, __ StackPointer(), kNumSavedRegs * kPointerSize);
+
+  {
+    // Create a dummy frame, as CallCFunction requires this.
+    FrameScope frame(masm, StackFrame::MANUAL);
+    __ CallCFunction(x10, 2, 0);
+  }
+
+  __ PopCPURegList(kCallerSaved);
+  __ Ret();
+}
+
+
+void DirectCEntryStub::Generate(MacroAssembler* masm) {
+  // When calling into C++ code the stack pointer must be csp.
+  // Therefore this code must use csp for peek/poke operations when the
+  // stub is generated. When the stub is called
+  // (via DirectCEntryStub::GenerateCall), the caller must setup an ExitFrame
+  // and configure the stack pointer *before* doing the call.
+  const Register old_stack_pointer = __ StackPointer();
+  __ SetStackPointer(csp);
+
+  // Put return address on the stack (accessible to GC through exit frame pc).
+  __ Poke(lr, 0);
+  // Call the C++ function.
+  __ Blr(x10);
+  // Return to calling code.
+  __ Peek(lr, 0);
+  __ AssertFPCRState();
+  __ Ret();
+
+  __ SetStackPointer(old_stack_pointer);
+}
+
+void DirectCEntryStub::GenerateCall(MacroAssembler* masm,
+                                    Register target) {
+  // Make sure the caller configured the stack pointer (see comment in
+  // DirectCEntryStub::Generate).
+  DCHECK(csp.Is(__ StackPointer()));
+
+  intptr_t code =
+      reinterpret_cast<intptr_t>(GetCode().location());
+  __ Mov(lr, Operand(code, RelocInfo::CODE_TARGET));
+  __ Mov(x10, target);
+  // Branch to the stub.
+  __ Blr(lr);
+}
+
+
+// Probe the name dictionary in the 'elements' register.
+// Jump to the 'done' label if a property with the given name is found.
+// Jump to the 'miss' label otherwise.
+//
+// If lookup was successful 'scratch2' will be equal to elements + 4 * index.
+// 'elements' and 'name' registers are preserved on miss.
+void NameDictionaryLookupStub::GeneratePositiveLookup(
+    MacroAssembler* masm,
+    Label* miss,
+    Label* done,
+    Register elements,
+    Register name,
+    Register scratch1,
+    Register scratch2) {
+  DCHECK(!AreAliased(elements, name, scratch1, scratch2));
+
+  // Assert that name contains a string.
+  __ AssertName(name);
+
+  // Compute the capacity mask.
+  __ Ldrsw(scratch1, UntagSmiFieldMemOperand(elements, kCapacityOffset));
+  __ Sub(scratch1, scratch1, 1);
+
+  // Generate an unrolled loop that performs a few probes before giving up.
+  for (int i = 0; i < kInlinedProbes; i++) {
+    // Compute the masked index: (hash + i + i * i) & mask.
+    __ Ldr(scratch2, FieldMemOperand(name, Name::kHashFieldOffset));
+    if (i > 0) {
+      // Add the probe offset (i + i * i) left shifted to avoid right shifting
+      // the hash in a separate instruction. The value hash + i + i * i is right
+      // shifted in the following and instruction.
+      DCHECK(NameDictionary::GetProbeOffset(i) <
+          1 << (32 - Name::kHashFieldOffset));
+      __ Add(scratch2, scratch2, Operand(
+          NameDictionary::GetProbeOffset(i) << Name::kHashShift));
+    }
+    __ And(scratch2, scratch1, Operand(scratch2, LSR, Name::kHashShift));
+
+    // Scale the index by multiplying by the element size.
+    DCHECK(NameDictionary::kEntrySize == 3);
+    __ Add(scratch2, scratch2, Operand(scratch2, LSL, 1));
+
+    // Check if the key is identical to the name.
+    UseScratchRegisterScope temps(masm);
+    Register scratch3 = temps.AcquireX();
+    __ Add(scratch2, elements, Operand(scratch2, LSL, kPointerSizeLog2));
+    __ Ldr(scratch3, FieldMemOperand(scratch2, kElementsStartOffset));
+    __ Cmp(name, scratch3);
+    __ B(eq, done);
+  }
+
+  // The inlined probes didn't find the entry.
+  // Call the complete stub to scan the whole dictionary.
+
+  CPURegList spill_list(CPURegister::kRegister, kXRegSizeInBits, 0, 6);
+  spill_list.Combine(lr);
+  spill_list.Remove(scratch1);
+  spill_list.Remove(scratch2);
+
+  __ PushCPURegList(spill_list);
+
+  if (name.is(x0)) {
+    DCHECK(!elements.is(x1));
+    __ Mov(x1, name);
+    __ Mov(x0, elements);
+  } else {
+    __ Mov(x0, elements);
+    __ Mov(x1, name);
+  }
+
+  Label not_found;
+  NameDictionaryLookupStub stub(masm->isolate(), POSITIVE_LOOKUP);
+  __ CallStub(&stub);
+  __ Cbz(x0, &not_found);
+  __ Mov(scratch2, x2);  // Move entry index into scratch2.
+  __ PopCPURegList(spill_list);
+  __ B(done);
+
+  __ Bind(&not_found);
+  __ PopCPURegList(spill_list);
+  __ B(miss);
+}
+
+
+void NameDictionaryLookupStub::GenerateNegativeLookup(MacroAssembler* masm,
+                                                      Label* miss,
+                                                      Label* done,
+                                                      Register receiver,
+                                                      Register properties,
+                                                      Handle<Name> name,
+                                                      Register scratch0) {
+  DCHECK(!AreAliased(receiver, properties, scratch0));
+  DCHECK(name->IsUniqueName());
+  // If names of slots in range from 1 to kProbes - 1 for the hash value are
+  // not equal to the name and kProbes-th slot is not used (its name is the
+  // undefined value), it guarantees the hash table doesn't contain the
+  // property. It's true even if some slots represent deleted properties
+  // (their names are the hole value).
+  for (int i = 0; i < kInlinedProbes; i++) {
+    // scratch0 points to properties hash.
+    // Compute the masked index: (hash + i + i * i) & mask.
+    Register index = scratch0;
+    // Capacity is smi 2^n.
+    __ Ldrsw(index, UntagSmiFieldMemOperand(properties, kCapacityOffset));
+    __ Sub(index, index, 1);
+    __ And(index, index, name->Hash() + NameDictionary::GetProbeOffset(i));
+
+    // Scale the index by multiplying by the entry size.
+    DCHECK(NameDictionary::kEntrySize == 3);
+    __ Add(index, index, Operand(index, LSL, 1));  // index *= 3.
+
+    Register entity_name = scratch0;
+    // Having undefined at this place means the name is not contained.
+    Register tmp = index;
+    __ Add(tmp, properties, Operand(index, LSL, kPointerSizeLog2));
+    __ Ldr(entity_name, FieldMemOperand(tmp, kElementsStartOffset));
+
+    __ JumpIfRoot(entity_name, Heap::kUndefinedValueRootIndex, done);
+
+    // Stop if found the property.
+    __ Cmp(entity_name, Operand(name));
+    __ B(eq, miss);
+
+    Label good;
+    __ JumpIfRoot(entity_name, Heap::kTheHoleValueRootIndex, &good);
+
+    // Check if the entry name is not a unique name.
+    __ Ldr(entity_name, FieldMemOperand(entity_name, HeapObject::kMapOffset));
+    __ Ldrb(entity_name,
+            FieldMemOperand(entity_name, Map::kInstanceTypeOffset));
+    __ JumpIfNotUniqueNameInstanceType(entity_name, miss);
+    __ Bind(&good);
+  }
+
+  CPURegList spill_list(CPURegister::kRegister, kXRegSizeInBits, 0, 6);
+  spill_list.Combine(lr);
+  spill_list.Remove(scratch0);  // Scratch registers don't need to be preserved.
+
+  __ PushCPURegList(spill_list);
+
+  __ Ldr(x0, FieldMemOperand(receiver, JSObject::kPropertiesOffset));
+  __ Mov(x1, Operand(name));
+  NameDictionaryLookupStub stub(masm->isolate(), NEGATIVE_LOOKUP);
+  __ CallStub(&stub);
+  // Move stub return value to scratch0. Note that scratch0 is not included in
+  // spill_list and won't be clobbered by PopCPURegList.
+  __ Mov(scratch0, x0);
+  __ PopCPURegList(spill_list);
+
+  __ Cbz(scratch0, done);
+  __ B(miss);
+}
+
+
+void NameDictionaryLookupStub::Generate(MacroAssembler* masm) {
+  // This stub overrides SometimesSetsUpAFrame() to return false. That means
+  // we cannot call anything that could cause a GC from this stub.
+  //
+  // Arguments are in x0 and x1:
+  //   x0: property dictionary.
+  //   x1: the name of the property we are looking for.
+  //
+  // Return value is in x0 and is zero if lookup failed, non zero otherwise.
+  // If the lookup is successful, x2 will contains the index of the entry.
+
+  Register result = x0;
+  Register dictionary = x0;
+  Register key = x1;
+  Register index = x2;
+  Register mask = x3;
+  Register hash = x4;
+  Register undefined = x5;
+  Register entry_key = x6;
+
+  Label in_dictionary, maybe_in_dictionary, not_in_dictionary;
+
+  __ Ldrsw(mask, UntagSmiFieldMemOperand(dictionary, kCapacityOffset));
+  __ Sub(mask, mask, 1);
+
+  __ Ldr(hash, FieldMemOperand(key, Name::kHashFieldOffset));
+  __ LoadRoot(undefined, Heap::kUndefinedValueRootIndex);
+
+  for (int i = kInlinedProbes; i < kTotalProbes; i++) {
+    // Compute the masked index: (hash + i + i * i) & mask.
+    // Capacity is smi 2^n.
+    if (i > 0) {
+      // Add the probe offset (i + i * i) left shifted to avoid right shifting
+      // the hash in a separate instruction. The value hash + i + i * i is right
+      // shifted in the following and instruction.
+      DCHECK(NameDictionary::GetProbeOffset(i) <
+             1 << (32 - Name::kHashFieldOffset));
+      __ Add(index, hash,
+             NameDictionary::GetProbeOffset(i) << Name::kHashShift);
+    } else {
+      __ Mov(index, hash);
+    }
+    __ And(index, mask, Operand(index, LSR, Name::kHashShift));
+
+    // Scale the index by multiplying by the entry size.
+    DCHECK(NameDictionary::kEntrySize == 3);
+    __ Add(index, index, Operand(index, LSL, 1));  // index *= 3.
+
+    __ Add(index, dictionary, Operand(index, LSL, kPointerSizeLog2));
+    __ Ldr(entry_key, FieldMemOperand(index, kElementsStartOffset));
+
+    // Having undefined at this place means the name is not contained.
+    __ Cmp(entry_key, undefined);
+    __ B(eq, &not_in_dictionary);
+
+    // Stop if found the property.
+    __ Cmp(entry_key, key);
+    __ B(eq, &in_dictionary);
+
+    if (i != kTotalProbes - 1 && mode() == NEGATIVE_LOOKUP) {
+      // Check if the entry name is not a unique name.
+      __ Ldr(entry_key, FieldMemOperand(entry_key, HeapObject::kMapOffset));
+      __ Ldrb(entry_key, FieldMemOperand(entry_key, Map::kInstanceTypeOffset));
+      __ JumpIfNotUniqueNameInstanceType(entry_key, &maybe_in_dictionary);
+    }
+  }
+
+  __ Bind(&maybe_in_dictionary);
+  // If we are doing negative lookup then probing failure should be
+  // treated as a lookup success. For positive lookup, probing failure
+  // should be treated as lookup failure.
+  if (mode() == POSITIVE_LOOKUP) {
+    __ Mov(result, 0);
+    __ Ret();
+  }
+
+  __ Bind(&in_dictionary);
+  __ Mov(result, 1);
+  __ Ret();
+
+  __ Bind(&not_in_dictionary);
+  __ Mov(result, 0);
+  __ Ret();
+}
+
+
+template<class T>
+static void CreateArrayDispatch(MacroAssembler* masm,
+                                AllocationSiteOverrideMode mode) {
+  ASM_LOCATION("CreateArrayDispatch");
+  if (mode == DISABLE_ALLOCATION_SITES) {
+    T stub(masm->isolate(), GetInitialFastElementsKind(), mode);
+     __ TailCallStub(&stub);
+
+  } else if (mode == DONT_OVERRIDE) {
+    Register kind = x3;
+    int last_index =
+        GetSequenceIndexFromFastElementsKind(TERMINAL_FAST_ELEMENTS_KIND);
+    for (int i = 0; i <= last_index; ++i) {
+      Label next;
+      ElementsKind candidate_kind = GetFastElementsKindFromSequenceIndex(i);
+      // TODO(jbramley): Is this the best way to handle this? Can we make the
+      // tail calls conditional, rather than hopping over each one?
+      __ CompareAndBranch(kind, candidate_kind, ne, &next);
+      T stub(masm->isolate(), candidate_kind);
+      __ TailCallStub(&stub);
+      __ Bind(&next);
+    }
+
+    // If we reached this point there is a problem.
+    __ Abort(kUnexpectedElementsKindInArrayConstructor);
+
+  } else {
+    UNREACHABLE();
+  }
+}
+
+
+// TODO(jbramley): If this needs to be a special case, make it a proper template
+// specialization, and not a separate function.
+static void CreateArrayDispatchOneArgument(MacroAssembler* masm,
+                                           AllocationSiteOverrideMode mode) {
+  ASM_LOCATION("CreateArrayDispatchOneArgument");
+  // x0 - argc
+  // x1 - constructor?
+  // x2 - allocation site (if mode != DISABLE_ALLOCATION_SITES)
+  // x3 - kind (if mode != DISABLE_ALLOCATION_SITES)
+  // sp[0] - last argument
+
+  Register allocation_site = x2;
+  Register kind = x3;
+
+  Label normal_sequence;
+  if (mode == DONT_OVERRIDE) {
+    STATIC_ASSERT(FAST_SMI_ELEMENTS == 0);
+    STATIC_ASSERT(FAST_HOLEY_SMI_ELEMENTS == 1);
+    STATIC_ASSERT(FAST_ELEMENTS == 2);
+    STATIC_ASSERT(FAST_HOLEY_ELEMENTS == 3);
+    STATIC_ASSERT(FAST_DOUBLE_ELEMENTS == 4);
+    STATIC_ASSERT(FAST_HOLEY_DOUBLE_ELEMENTS == 5);
+
+    // Is the low bit set? If so, the array is holey.
+    __ Tbnz(kind, 0, &normal_sequence);
+  }
+
+  // Look at the last argument.
+  // TODO(jbramley): What does a 0 argument represent?
+  __ Peek(x10, 0);
+  __ Cbz(x10, &normal_sequence);
+
+  if (mode == DISABLE_ALLOCATION_SITES) {
+    ElementsKind initial = GetInitialFastElementsKind();
+    ElementsKind holey_initial = GetHoleyElementsKind(initial);
+
+    ArraySingleArgumentConstructorStub stub_holey(masm->isolate(),
+                                                  holey_initial,
+                                                  DISABLE_ALLOCATION_SITES);
+    __ TailCallStub(&stub_holey);
+
+    __ Bind(&normal_sequence);
+    ArraySingleArgumentConstructorStub stub(masm->isolate(),
+                                            initial,
+                                            DISABLE_ALLOCATION_SITES);
+    __ TailCallStub(&stub);
+  } else if (mode == DONT_OVERRIDE) {
+    // We are going to create a holey array, but our kind is non-holey.
+    // Fix kind and retry (only if we have an allocation site in the slot).
+    __ Orr(kind, kind, 1);
+
+    if (FLAG_debug_code) {
+      __ Ldr(x10, FieldMemOperand(allocation_site, 0));
+      __ JumpIfNotRoot(x10, Heap::kAllocationSiteMapRootIndex,
+                       &normal_sequence);
+      __ Assert(eq, kExpectedAllocationSite);
+    }
+
+    // Save the resulting elements kind in type info. We can't just store 'kind'
+    // in the AllocationSite::transition_info field because elements kind is
+    // restricted to a portion of the field; upper bits need to be left alone.
+    STATIC_ASSERT(AllocationSite::ElementsKindBits::kShift == 0);
+    __ Ldr(x11, FieldMemOperand(allocation_site,
+                                AllocationSite::kTransitionInfoOffset));
+    __ Add(x11, x11, Smi::FromInt(kFastElementsKindPackedToHoley));
+    __ Str(x11, FieldMemOperand(allocation_site,
+                                AllocationSite::kTransitionInfoOffset));
+
+    __ Bind(&normal_sequence);
+    int last_index =
+        GetSequenceIndexFromFastElementsKind(TERMINAL_FAST_ELEMENTS_KIND);
+    for (int i = 0; i <= last_index; ++i) {
+      Label next;
+      ElementsKind candidate_kind = GetFastElementsKindFromSequenceIndex(i);
+      __ CompareAndBranch(kind, candidate_kind, ne, &next);
+      ArraySingleArgumentConstructorStub stub(masm->isolate(), candidate_kind);
+      __ TailCallStub(&stub);
+      __ Bind(&next);
+    }
+
+    // If we reached this point there is a problem.
+    __ Abort(kUnexpectedElementsKindInArrayConstructor);
+  } else {
+    UNREACHABLE();
+  }
+}
+
+
+template<class T>
+static void ArrayConstructorStubAheadOfTimeHelper(Isolate* isolate) {
+  int to_index = GetSequenceIndexFromFastElementsKind(
+      TERMINAL_FAST_ELEMENTS_KIND);
+  for (int i = 0; i <= to_index; ++i) {
+    ElementsKind kind = GetFastElementsKindFromSequenceIndex(i);
+    T stub(isolate, kind);
+    stub.GetCode();
+    if (AllocationSite::GetMode(kind) != DONT_TRACK_ALLOCATION_SITE) {
+      T stub1(isolate, kind, DISABLE_ALLOCATION_SITES);
+      stub1.GetCode();
+    }
+  }
+}
+
+
+void ArrayConstructorStubBase::GenerateStubsAheadOfTime(Isolate* isolate) {
+  ArrayConstructorStubAheadOfTimeHelper<ArrayNoArgumentConstructorStub>(
+      isolate);
+  ArrayConstructorStubAheadOfTimeHelper<ArraySingleArgumentConstructorStub>(
+      isolate);
+  ArrayConstructorStubAheadOfTimeHelper<ArrayNArgumentsConstructorStub>(
+      isolate);
+}
+
+
+void InternalArrayConstructorStubBase::GenerateStubsAheadOfTime(
+    Isolate* isolate) {
+  ElementsKind kinds[2] = { FAST_ELEMENTS, FAST_HOLEY_ELEMENTS };
+  for (int i = 0; i < 2; i++) {
+    // For internal arrays we only need a few things
+    InternalArrayNoArgumentConstructorStub stubh1(isolate, kinds[i]);
+    stubh1.GetCode();
+    InternalArraySingleArgumentConstructorStub stubh2(isolate, kinds[i]);
+    stubh2.GetCode();
+    InternalArrayNArgumentsConstructorStub stubh3(isolate, kinds[i]);
+    stubh3.GetCode();
+  }
+}
+
+
+void ArrayConstructorStub::GenerateDispatchToArrayStub(
+    MacroAssembler* masm,
+    AllocationSiteOverrideMode mode) {
+  Register argc = x0;
+  if (argument_count() == ANY) {
+    Label zero_case, n_case;
+    __ Cbz(argc, &zero_case);
+    __ Cmp(argc, 1);
+    __ B(ne, &n_case);
+
+    // One argument.
+    CreateArrayDispatchOneArgument(masm, mode);
+
+    __ Bind(&zero_case);
+    // No arguments.
+    CreateArrayDispatch<ArrayNoArgumentConstructorStub>(masm, mode);
+
+    __ Bind(&n_case);
+    // N arguments.
+    CreateArrayDispatch<ArrayNArgumentsConstructorStub>(masm, mode);
+
+  } else if (argument_count() == NONE) {
+    CreateArrayDispatch<ArrayNoArgumentConstructorStub>(masm, mode);
+  } else if (argument_count() == ONE) {
+    CreateArrayDispatchOneArgument(masm, mode);
+  } else if (argument_count() == MORE_THAN_ONE) {
+    CreateArrayDispatch<ArrayNArgumentsConstructorStub>(masm, mode);
+  } else {
+    UNREACHABLE();
+  }
+}
+
+
+void ArrayConstructorStub::Generate(MacroAssembler* masm) {
+  ASM_LOCATION("ArrayConstructorStub::Generate");
+  // ----------- S t a t e -------------
+  //  -- x0 : argc (only if argument_count() == ANY)
+  //  -- x1 : constructor
+  //  -- x2 : AllocationSite or undefined
+  //  -- sp[0] : return address
+  //  -- sp[4] : last argument
+  // -----------------------------------
+  Register constructor = x1;
+  Register allocation_site = x2;
+
+  if (FLAG_debug_code) {
+    // The array construct code is only set for the global and natives
+    // builtin Array functions which always have maps.
+
+    Label unexpected_map, map_ok;
+    // Initial map for the builtin Array function should be a map.
+    __ Ldr(x10, FieldMemOperand(constructor,
+                                JSFunction::kPrototypeOrInitialMapOffset));
+    // Will both indicate a NULL and a Smi.
+    __ JumpIfSmi(x10, &unexpected_map);
+    __ JumpIfObjectType(x10, x10, x11, MAP_TYPE, &map_ok);
+    __ Bind(&unexpected_map);
+    __ Abort(kUnexpectedInitialMapForArrayFunction);
+    __ Bind(&map_ok);
+
+    // We should either have undefined in the allocation_site register or a
+    // valid AllocationSite.
+    __ AssertUndefinedOrAllocationSite(allocation_site, x10);
+  }
+
+  Register kind = x3;
+  Label no_info;
+  // Get the elements kind and case on that.
+  __ JumpIfRoot(allocation_site, Heap::kUndefinedValueRootIndex, &no_info);
+
+  __ Ldrsw(kind,
+           UntagSmiFieldMemOperand(allocation_site,
+                                   AllocationSite::kTransitionInfoOffset));
+  __ And(kind, kind, AllocationSite::ElementsKindBits::kMask);
+  GenerateDispatchToArrayStub(masm, DONT_OVERRIDE);
+
+  __ Bind(&no_info);
+  GenerateDispatchToArrayStub(masm, DISABLE_ALLOCATION_SITES);
+}
+
+
+void InternalArrayConstructorStub::GenerateCase(
+    MacroAssembler* masm, ElementsKind kind) {
+  Label zero_case, n_case;
+  Register argc = x0;
+
+  __ Cbz(argc, &zero_case);
+  __ CompareAndBranch(argc, 1, ne, &n_case);
+
+  // One argument.
+  if (IsFastPackedElementsKind(kind)) {
+    Label packed_case;
+
+    // We might need to create a holey array; look at the first argument.
+    __ Peek(x10, 0);
+    __ Cbz(x10, &packed_case);
+
+    InternalArraySingleArgumentConstructorStub
+        stub1_holey(isolate(), GetHoleyElementsKind(kind));
+    __ TailCallStub(&stub1_holey);
+
+    __ Bind(&packed_case);
+  }
+  InternalArraySingleArgumentConstructorStub stub1(isolate(), kind);
+  __ TailCallStub(&stub1);
+
+  __ Bind(&zero_case);
+  // No arguments.
+  InternalArrayNoArgumentConstructorStub stub0(isolate(), kind);
+  __ TailCallStub(&stub0);
+
+  __ Bind(&n_case);
+  // N arguments.
+  InternalArrayNArgumentsConstructorStub stubN(isolate(), kind);
+  __ TailCallStub(&stubN);
+}
+
+
+void InternalArrayConstructorStub::Generate(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- x0 : argc
+  //  -- x1 : constructor
+  //  -- sp[0] : return address
+  //  -- sp[4] : last argument
+  // -----------------------------------
+
+  Register constructor = x1;
+
+  if (FLAG_debug_code) {
+    // The array construct code is only set for the global and natives
+    // builtin Array functions which always have maps.
+
+    Label unexpected_map, map_ok;
+    // Initial map for the builtin Array function should be a map.
+    __ Ldr(x10, FieldMemOperand(constructor,
+                                JSFunction::kPrototypeOrInitialMapOffset));
+    // Will both indicate a NULL and a Smi.
+    __ JumpIfSmi(x10, &unexpected_map);
+    __ JumpIfObjectType(x10, x10, x11, MAP_TYPE, &map_ok);
+    __ Bind(&unexpected_map);
+    __ Abort(kUnexpectedInitialMapForArrayFunction);
+    __ Bind(&map_ok);
+  }
+
+  Register kind = w3;
+  // Figure out the right elements kind
+  __ Ldr(x10, FieldMemOperand(constructor,
+                              JSFunction::kPrototypeOrInitialMapOffset));
+
+  // Retrieve elements_kind from map.
+  __ LoadElementsKindFromMap(kind, x10);
+
+  if (FLAG_debug_code) {
+    Label done;
+    __ Cmp(x3, FAST_ELEMENTS);
+    __ Ccmp(x3, FAST_HOLEY_ELEMENTS, ZFlag, ne);
+    __ Assert(eq, kInvalidElementsKindForInternalArrayOrInternalPackedArray);
+  }
+
+  Label fast_elements_case;
+  __ CompareAndBranch(kind, FAST_ELEMENTS, eq, &fast_elements_case);
+  GenerateCase(masm, FAST_HOLEY_ELEMENTS);
+
+  __ Bind(&fast_elements_case);
+  GenerateCase(masm, FAST_ELEMENTS);
+}
+
+
+void CallApiFunctionStub::Generate(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- x0                  : callee
+  //  -- x4                  : call_data
+  //  -- x2                  : holder
+  //  -- x1                  : api_function_address
+  //  -- cp                  : context
+  //  --
+  //  -- sp[0]               : last argument
+  //  -- ...
+  //  -- sp[(argc - 1) * 8]  : first argument
+  //  -- sp[argc * 8]        : receiver
+  // -----------------------------------
+
+  Register callee = x0;
+  Register call_data = x4;
+  Register holder = x2;
+  Register api_function_address = x1;
+  Register context = cp;
+
+  int argc = this->argc();
+  bool is_store = this->is_store();
+  bool call_data_undefined = this->call_data_undefined();
+
+  typedef FunctionCallbackArguments FCA;
+
+  STATIC_ASSERT(FCA::kContextSaveIndex == 6);
+  STATIC_ASSERT(FCA::kCalleeIndex == 5);
+  STATIC_ASSERT(FCA::kDataIndex == 4);
+  STATIC_ASSERT(FCA::kReturnValueOffset == 3);
+  STATIC_ASSERT(FCA::kReturnValueDefaultValueIndex == 2);
+  STATIC_ASSERT(FCA::kIsolateIndex == 1);
+  STATIC_ASSERT(FCA::kHolderIndex == 0);
+  STATIC_ASSERT(FCA::kArgsLength == 7);
+
+  // FunctionCallbackArguments: context, callee and call data.
+  __ Push(context, callee, call_data);
+
+  // Load context from callee
+  __ Ldr(context, FieldMemOperand(callee, JSFunction::kContextOffset));
+
+  if (!call_data_undefined) {
+    __ LoadRoot(call_data, Heap::kUndefinedValueRootIndex);
+  }
+  Register isolate_reg = x5;
+  __ Mov(isolate_reg, ExternalReference::isolate_address(isolate()));
+
+  // FunctionCallbackArguments:
+  //    return value, return value default, isolate, holder.
+  __ Push(call_data, call_data, isolate_reg, holder);
+
+  // Prepare arguments.
+  Register args = x6;
+  __ Mov(args, masm->StackPointer());
+
+  // Allocate the v8::Arguments structure in the arguments' space, since it's
+  // not controlled by GC.
+  const int kApiStackSpace = 4;
+
+  // Allocate space for CallApiFunctionAndReturn can store some scratch
+  // registeres on the stack.
+  const int kCallApiFunctionSpillSpace = 4;
+
+  FrameScope frame_scope(masm, StackFrame::MANUAL);
+  __ EnterExitFrame(false, x10, kApiStackSpace + kCallApiFunctionSpillSpace);
+
+  DCHECK(!AreAliased(x0, api_function_address));
+  // x0 = FunctionCallbackInfo&
+  // Arguments is after the return address.
+  __ Add(x0, masm->StackPointer(), 1 * kPointerSize);
+  // FunctionCallbackInfo::implicit_args_ and FunctionCallbackInfo::values_
+  __ Add(x10, args, Operand((FCA::kArgsLength - 1 + argc) * kPointerSize));
+  __ Stp(args, x10, MemOperand(x0, 0 * kPointerSize));
+  // FunctionCallbackInfo::length_ = argc and
+  // FunctionCallbackInfo::is_construct_call = 0
+  __ Mov(x10, argc);
+  __ Stp(x10, xzr, MemOperand(x0, 2 * kPointerSize));
+
+  const int kStackUnwindSpace = argc + FCA::kArgsLength + 1;
+  ExternalReference thunk_ref =
+      ExternalReference::invoke_function_callback(isolate());
+
+  AllowExternalCallThatCantCauseGC scope(masm);
+  MemOperand context_restore_operand(
+      fp, (2 + FCA::kContextSaveIndex) * kPointerSize);
+  // Stores return the first js argument
+  int return_value_offset = 0;
+  if (is_store) {
+    return_value_offset = 2 + FCA::kArgsLength;
+  } else {
+    return_value_offset = 2 + FCA::kReturnValueOffset;
+  }
+  MemOperand return_value_operand(fp, return_value_offset * kPointerSize);
+
+  const int spill_offset = 1 + kApiStackSpace;
+  __ CallApiFunctionAndReturn(api_function_address,
+                              thunk_ref,
+                              kStackUnwindSpace,
+                              spill_offset,
+                              return_value_operand,
+                              &context_restore_operand);
+}
+
+
+void CallApiGetterStub::Generate(MacroAssembler* masm) {
+  // ----------- S t a t e -------------
+  //  -- sp[0]                  : name
+  //  -- sp[8 - kArgsLength*8]  : PropertyCallbackArguments object
+  //  -- ...
+  //  -- x2                     : api_function_address
+  // -----------------------------------
+
+  Register api_function_address = ApiGetterDescriptor::function_address();
+  DCHECK(api_function_address.is(x2));
+
+  __ Mov(x0, masm->StackPointer());  // x0 = Handle<Name>
+  __ Add(x1, x0, 1 * kPointerSize);  // x1 = PCA
+
+  const int kApiStackSpace = 1;
+
+  // Allocate space for CallApiFunctionAndReturn can store some scratch
+  // registeres on the stack.
+  const int kCallApiFunctionSpillSpace = 4;
+
+  FrameScope frame_scope(masm, StackFrame::MANUAL);
+  __ EnterExitFrame(false, x10, kApiStackSpace + kCallApiFunctionSpillSpace);
+
+  // Create PropertyAccessorInfo instance on the stack above the exit frame with
+  // x1 (internal::Object** args_) as the data.
+  __ Poke(x1, 1 * kPointerSize);
+  __ Add(x1, masm->StackPointer(), 1 * kPointerSize);  // x1 = AccessorInfo&
+
+  const int kStackUnwindSpace = PropertyCallbackArguments::kArgsLength + 1;
+
+  ExternalReference thunk_ref =
+      ExternalReference::invoke_accessor_getter_callback(isolate());
+
+  const int spill_offset = 1 + kApiStackSpace;
+  __ CallApiFunctionAndReturn(api_function_address,
+                              thunk_ref,
+                              kStackUnwindSpace,
+                              spill_offset,
+                              MemOperand(fp, 6 * kPointerSize),
+                              NULL);
+}
+
+
+#undef __
+
+} }  // namespace v8::internal
+
+#endif  // V8_TARGET_ARCH_ARM64