A64: add missing files.

src/a64/macro-assembler-a64.h

+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_A64_MACRO_ASSEMBLER_A64_H_
+#define V8_A64_MACRO_ASSEMBLER_A64_H_
+
+#include "v8globals.h"
+#include "globals.h"
+
+#include "a64/assembler-a64-inl.h"
+
+namespace v8 {
+namespace internal {
+
+#define LS_MACRO_LIST(V)                                      \
+  V(Ldrb, Register&, rt, LDRB_w)                              \
+  V(Strb, Register&, rt, STRB_w)                              \
+  V(Ldrsb, Register&, rt, rt.Is64Bits() ? LDRSB_x : LDRSB_w)  \
+  V(Ldrh, Register&, rt, LDRH_w)                              \
+  V(Strh, Register&, rt, STRH_w)                              \
+  V(Ldrsh, Register&, rt, rt.Is64Bits() ? LDRSH_x : LDRSH_w)  \
+  V(Ldr, CPURegister&, rt, LoadOpFor(rt))                     \
+  V(Str, CPURegister&, rt, StoreOpFor(rt))                    \
+  V(Ldrsw, Register&, rt, LDRSW_x)
+
+
+// ----------------------------------------------------------------------------
+// Static helper functions
+
+// Generate a MemOperand for loading a field from an object.
+inline MemOperand FieldMemOperand(Register object, int offset);
+inline MemOperand UntagSmiFieldMemOperand(Register object, int offset);
+
+// Generate a MemOperand for loading a SMI from memory.
+inline MemOperand UntagSmiMemOperand(Register object, int offset);
+
+
+// ----------------------------------------------------------------------------
+// MacroAssembler
+
+enum PregenExpectation { MAYBE_PREGENERATED, EXPECT_PREGENERATED };
+enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
+enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
+enum LinkRegisterStatus { kLRHasNotBeenSaved, kLRHasBeenSaved };
+enum TargetAddressStorageMode {
+  CAN_INLINE_TARGET_ADDRESS,
+  NEVER_INLINE_TARGET_ADDRESS
+};
+enum UntagMode { kNotSpeculativeUntag, kSpeculativeUntag };
+enum ArrayHasHoles { kArrayCantHaveHoles, kArrayCanHaveHoles };
+enum CopyHint { kCopyUnknown, kCopyShort, kCopyLong };
+enum DiscardMoveMode { kDontDiscardForSameWReg, kDiscardForSameWReg };
+
+class MacroAssembler : public Assembler {
+ public:
+  MacroAssembler(Isolate* isolate, byte * buffer, unsigned buffer_size);
+
+  inline Handle<Object> CodeObject();
+
+  // Instruction set functions ------------------------------------------------
+  // Logical macros.
+  inline void And(const Register& rd,
+                  const Register& rn,
+                  const Operand& operand);
+  inline void Ands(const Register& rd,
+                   const Register& rn,
+                   const Operand& operand);
+  inline void Bic(const Register& rd,
+                  const Register& rn,
+                  const Operand& operand);
+  inline void Bics(const Register& rd,
+                   const Register& rn,
+                   const Operand& operand);
+  inline void Orr(const Register& rd,
+                  const Register& rn,
+                  const Operand& operand);
+  inline void Orn(const Register& rd,
+                  const Register& rn,
+                  const Operand& operand);
+  inline void Eor(const Register& rd,
+                  const Register& rn,
+                  const Operand& operand);
+  inline void Eon(const Register& rd,
+                  const Register& rn,
+                  const Operand& operand);
+  inline void Tst(const Register& rn, const Operand& operand);
+  void LogicalMacro(const Register& rd,
+                    const Register& rn,
+                    const Operand& operand,
+                    LogicalOp op);
+
+  // Add and sub macros.
+  inline void Add(const Register& rd,
+                  const Register& rn,
+                  const Operand& operand);
+  inline void Adds(const Register& rd,
+                   const Register& rn,
+                   const Operand& operand);
+  inline void Sub(const Register& rd,
+                  const Register& rn,
+                  const Operand& operand);
+  inline void Subs(const Register& rd,
+                   const Register& rn,
+                   const Operand& operand);
+  inline void Cmn(const Register& rn, const Operand& operand);
+  inline void Cmp(const Register& rn, const Operand& operand);
+  inline void Neg(const Register& rd,
+                  const Operand& operand);
+  inline void Negs(const Register& rd,
+                   const Operand& operand);
+
+  void AddSubMacro(const Register& rd,
+                   const Register& rn,
+                   const Operand& operand,
+                   FlagsUpdate S,
+                   AddSubOp op);
+
+  // Add/sub with carry macros.
+  inline void Adc(const Register& rd,
+                  const Register& rn,
+                  const Operand& operand);
+  inline void Adcs(const Register& rd,
+                   const Register& rn,
+                   const Operand& operand);
+  inline void Sbc(const Register& rd,
+                  const Register& rn,
+                  const Operand& operand);
+  inline void Sbcs(const Register& rd,
+                   const Register& rn,
+                   const Operand& operand);
+  inline void Ngc(const Register& rd,
+                  const Operand& operand);
+  inline void Ngcs(const Register& rd,
+                   const Operand& operand);
+  void AddSubWithCarryMacro(const Register& rd,
+                            const Register& rn,
+                            const Operand& operand,
+                            FlagsUpdate S,
+                            AddSubWithCarryOp op);
+
+  // Move macros.
+  void Mov(const Register& rd,
+           const Operand& operand,
+           DiscardMoveMode discard_mode = kDontDiscardForSameWReg);
+  void Mov(const Register& rd, uint64_t imm);
+  inline void Mvn(const Register& rd, uint64_t imm);
+  void Mvn(const Register& rd, const Operand& operand);
+  static bool IsImmMovn(uint64_t imm, unsigned reg_size);
+  static bool IsImmMovz(uint64_t imm, unsigned reg_size);
+  static unsigned CountClearHalfWords(uint64_t imm, unsigned reg_size);
+
+  // Conditional macros.
+  inline void Ccmp(const Register& rn,
+                   const Operand& operand,
+                   StatusFlags nzcv,
+                   Condition cond);
+  inline void Ccmn(const Register& rn,
+                   const Operand& operand,
+                   StatusFlags nzcv,
+                   Condition cond);
+  void ConditionalCompareMacro(const Register& rn,
+                               const Operand& operand,
+                               StatusFlags nzcv,
+                               Condition cond,
+                               ConditionalCompareOp op);
+  void Csel(const Register& rd,
+            const Register& rn,
+            const Operand& operand,
+            Condition cond);
+
+  // Load/store macros.
+#define DECLARE_FUNCTION(FN, REGTYPE, REG, OP) \
+  inline void FN(const REGTYPE REG, const MemOperand& addr);
+  LS_MACRO_LIST(DECLARE_FUNCTION)
+#undef DECLARE_FUNCTION
+
+  void LoadStoreMacro(const CPURegister& rt,
+                      const MemOperand& addr,
+                      LoadStoreOp op);
+
+  // Remaining instructions are simple pass-through calls to the assembler.
+  inline void Adr(const Register& rd, Label* label);
+  inline void Asr(const Register& rd, const Register& rn, unsigned shift);
+  inline void Asr(const Register& rd, const Register& rn, const Register& rm);
+  inline void B(Label* label);
+  inline void B(Condition cond, Label* label);
+  inline void B(Label* label, Condition cond);
+  inline void Bfi(const Register& rd,
+                  const Register& rn,
+                  unsigned lsb,
+                  unsigned width);
+  inline void Bfxil(const Register& rd,
+                    const Register& rn,
+                    unsigned lsb,
+                    unsigned width);
+  inline void Bind(Label* label);
+  inline void Bl(Label* label);
+  inline void Blr(const Register& xn);
+  inline void Br(const Register& xn);
+  inline void Brk(int code);
+  inline void Cbnz(const Register& rt, Label* label);
+  inline void Cbz(const Register& rt, Label* label);
+  inline void Cinc(const Register& rd, const Register& rn, Condition cond);
+  inline void Cinv(const Register& rd, const Register& rn, Condition cond);
+  inline void Cls(const Register& rd, const Register& rn);
+  inline void Clz(const Register& rd, const Register& rn);
+  inline void Cneg(const Register& rd, const Register& rn, Condition cond);
+  inline void CzeroX(const Register& rd, Condition cond);
+  inline void CmovX(const Register& rd, const Register& rn, Condition cond);
+  inline void Cset(const Register& rd, Condition cond);
+  inline void Csetm(const Register& rd, Condition cond);
+  inline void Csinc(const Register& rd,
+                    const Register& rn,
+                    const Register& rm,
+                    Condition cond);
+  inline void Csinv(const Register& rd,
+                    const Register& rn,
+                    const Register& rm,
+                    Condition cond);
+  inline void Csneg(const Register& rd,
+                    const Register& rn,
+                    const Register& rm,
+                    Condition cond);
+  inline void Dmb(BarrierDomain domain, BarrierType type);
+  inline void Dsb(BarrierDomain domain, BarrierType type);
+  inline void Debug(const char* message, uint32_t code, Instr params = BREAK);
+  inline void Extr(const Register& rd,
+                   const Register& rn,
+                   const Register& rm,
+                   unsigned lsb);
+  inline void Fabs(const FPRegister& fd, const FPRegister& fn);
+  inline void Fadd(const FPRegister& fd,
+                   const FPRegister& fn,
+                   const FPRegister& fm);
+  inline void Fccmp(const FPRegister& fn,
+                    const FPRegister& fm,
+                    StatusFlags nzcv,
+                    Condition cond);
+  inline void Fcmp(const FPRegister& fn, const FPRegister& fm);
+  inline void Fcmp(const FPRegister& fn, double value);
+  inline void Fcsel(const FPRegister& fd,
+                    const FPRegister& fn,
+                    const FPRegister& fm,
+                    Condition cond);
+  inline void Fcvt(const FPRegister& fd, const FPRegister& fn);
+  inline void Fcvtas(const Register& rd, const FPRegister& fn);
+  inline void Fcvtau(const Register& rd, const FPRegister& fn);
+  inline void Fcvtms(const Register& rd, const FPRegister& fn);
+  inline void Fcvtmu(const Register& rd, const FPRegister& fn);
+  inline void Fcvtns(const Register& rd, const FPRegister& fn);
+  inline void Fcvtnu(const Register& rd, const FPRegister& fn);
+  inline void Fcvtzs(const Register& rd, const FPRegister& fn);
+  inline void Fcvtzu(const Register& rd, const FPRegister& fn);
+  inline void Fdiv(const FPRegister& fd,
+                   const FPRegister& fn,
+                   const FPRegister& fm);
+  inline void Fmadd(const FPRegister& fd,
+                    const FPRegister& fn,
+                    const FPRegister& fm,
+                    const FPRegister& fa);
+  inline void Fmax(const FPRegister& fd,
+                   const FPRegister& fn,
+                   const FPRegister& fm);
+  inline void Fmaxnm(const FPRegister& fd,
+                     const FPRegister& fn,
+                     const FPRegister& fm);
+  inline void Fmin(const FPRegister& fd,
+                   const FPRegister& fn,
+                   const FPRegister& fm);
+  inline void Fminnm(const FPRegister& fd,
+                     const FPRegister& fn,
+                     const FPRegister& fm);
+  inline void Fmov(FPRegister fd, FPRegister fn);
+  inline void Fmov(FPRegister fd, Register rn);
+  inline void Fmov(FPRegister fd, double imm);
+  inline void Fmov(Register rd, FPRegister fn);
+  inline void Fmsub(const FPRegister& fd,
+                    const FPRegister& fn,
+                    const FPRegister& fm,
+                    const FPRegister& fa);
+  inline void Fmul(const FPRegister& fd,
+                   const FPRegister& fn,
+                   const FPRegister& fm);
+  inline void Fneg(const FPRegister& fd, const FPRegister& fn);
+  inline void Fnmadd(const FPRegister& fd,
+                     const FPRegister& fn,
+                     const FPRegister& fm,
+                     const FPRegister& fa);
+  inline void Fnmsub(const FPRegister& fd,
+                     const FPRegister& fn,
+                     const FPRegister& fm,
+                     const FPRegister& fa);
+  inline void Frinta(const FPRegister& fd, const FPRegister& fn);
+  inline void Frintn(const FPRegister& fd, const FPRegister& fn);
+  inline void Frintz(const FPRegister& fd, const FPRegister& fn);
+  inline void Fsqrt(const FPRegister& fd, const FPRegister& fn);
+  inline void Fsub(const FPRegister& fd,
+                   const FPRegister& fn,
+                   const FPRegister& fm);
+  inline void Hint(SystemHint code);
+  inline void Hlt(int code);
+  inline void Isb();
+  inline void Ldnp(const CPURegister& rt,
+                   const CPURegister& rt2,
+                   const MemOperand& src);
+  inline void Ldp(const CPURegister& rt,
+                  const CPURegister& rt2,
+                  const MemOperand& src);
+  inline void Ldpsw(const Register& rt,
+                    const Register& rt2,
+                    const MemOperand& src);
+  inline void Ldr(const FPRegister& ft, double imm);
+  inline void Ldr(const Register& rt, uint64_t imm);
+  inline void Lsl(const Register& rd, const Register& rn, unsigned shift);
+  inline void Lsl(const Register& rd, const Register& rn, const Register& rm);
+  inline void Lsr(const Register& rd, const Register& rn, unsigned shift);
+  inline void Lsr(const Register& rd, const Register& rn, const Register& rm);
+  inline void Madd(const Register& rd,
+                   const Register& rn,
+                   const Register& rm,
+                   const Register& ra);
+  inline void Mneg(const Register& rd, const Register& rn, const Register& rm);
+  inline void Mov(const Register& rd, const Register& rm);
+  inline void Movk(const Register& rd, uint64_t imm, int shift = -1);
+  inline void Mrs(const Register& rt, SystemRegister sysreg);
+  inline void Msr(SystemRegister sysreg, const Register& rt);
+  inline void Msub(const Register& rd,
+                   const Register& rn,
+                   const Register& rm,
+                   const Register& ra);
+  inline void Mul(const Register& rd, const Register& rn, const Register& rm);
+  inline void Nop() { nop(); }
+  inline void Rbit(const Register& rd, const Register& rn);
+  inline void Ret(const Register& xn = lr);
+  inline void Rev(const Register& rd, const Register& rn);
+  inline void Rev16(const Register& rd, const Register& rn);
+  inline void Rev32(const Register& rd, const Register& rn);
+  inline void Ror(const Register& rd, const Register& rs, unsigned shift);
+  inline void Ror(const Register& rd, const Register& rn, const Register& rm);
+  inline void Sbfiz(const Register& rd,
+                    const Register& rn,
+                    unsigned lsb,
+                    unsigned width);
+  inline void Sbfx(const Register& rd,
+                   const Register& rn,
+                   unsigned lsb,
+                   unsigned width);
+  inline void Scvtf(const FPRegister& fd,
+                    const Register& rn,
+                    unsigned fbits = 0);
+  inline void Sdiv(const Register& rd, const Register& rn, const Register& rm);
+  inline void Smaddl(const Register& rd,
+                     const Register& rn,
+                     const Register& rm,
+                     const Register& ra);
+  inline void Smsubl(const Register& rd,
+                     const Register& rn,
+                     const Register& rm,
+                     const Register& ra);
+  inline void Smull(const Register& rd,
+                    const Register& rn,
+                    const Register& rm);
+  inline void Smulh(const Register& rd,
+                    const Register& rn,
+                    const Register& rm);
+  inline void Stnp(const CPURegister& rt,
+                   const CPURegister& rt2,
+                   const MemOperand& dst);
+  inline void Stp(const CPURegister& rt,
+                  const CPURegister& rt2,
+                  const MemOperand& dst);
+  inline void Sxtb(const Register& rd, const Register& rn);
+  inline void Sxth(const Register& rd, const Register& rn);
+  inline void Sxtw(const Register& rd, const Register& rn);
+  inline void Tbnz(const Register& rt, unsigned bit_pos, Label* label);
+  inline void Tbz(const Register& rt, unsigned bit_pos, Label* label);
+  inline void Ubfiz(const Register& rd,
+                    const Register& rn,
+                    unsigned lsb,
+                    unsigned width);
+  inline void Ubfx(const Register& rd,
+                   const Register& rn,
+                   unsigned lsb,
+                   unsigned width);
+  inline void Ucvtf(const FPRegister& fd,
+                    const Register& rn,
+                    unsigned fbits = 0);
+  inline void Udiv(const Register& rd, const Register& rn, const Register& rm);
+  inline void Umaddl(const Register& rd,
+                     const Register& rn,
+                     const Register& rm,
+                     const Register& ra);
+  inline void Umsubl(const Register& rd,
+                     const Register& rn,
+                     const Register& rm,
+                     const Register& ra);
+  inline void Unreachable();
+  inline void Uxtb(const Register& rd, const Register& rn);
+  inline void Uxth(const Register& rd, const Register& rn);
+  inline void Uxtw(const Register& rd, const Register& rn);
+
+  // Pseudo-instructions ------------------------------------------------------
+
+  // Compute rd = abs(rm).
+  // This function clobbers the condition flags.
+  //
+  // If rm is the minimum representable value, the result is not representable.
+  // Handlers for each case can be specified using the relevant labels.
+  void Abs(const Register& rd, const Register& rm,
+           Label * is_not_representable = NULL,
+           Label * is_representable = NULL);
+
+  // Push or pop up to 4 registers of the same width to or from the stack,
+  // using the current stack pointer as set by SetStackPointer.
+  //
+  // If an argument register is 'NoReg', all further arguments are also assumed
+  // to be 'NoReg', and are thus not pushed or popped.
+  //
+  // Arguments are ordered such that "Push(a, b);" is functionally equivalent
+  // to "Push(a); Push(b);".
+  //
+  // It is valid to push the same register more than once, and there is no
+  // restriction on the order in which registers are specified.
+  //
+  // It is not valid to pop into the same register more than once in one
+  // operation, not even into the zero register.
+  //
+  // If the current stack pointer (as set by SetStackPointer) is csp, then it
+  // must be aligned to 16 bytes on entry and the total size of the specified
+  // registers must also be a multiple of 16 bytes.
+  //
+  // Even if the current stack pointer is not the system stack pointer (csp),
+  // Push (and derived methods) will still modify the system stack pointer in
+  // order to comply with ABI rules about accessing memory below the system
+  // stack pointer.
+  //
+  // Other than the registers passed into Pop, the stack pointer and (possibly)
+  // the system stack pointer, these methods do not modify any other registers.
+  // Scratch registers such as Tmp0() and Tmp1() are preserved.
+  void Push(const CPURegister& src0, const CPURegister& src1 = NoReg,
+            const CPURegister& src2 = NoReg, const CPURegister& src3 = NoReg);
+  void Pop(const CPURegister& dst0, const CPURegister& dst1 = NoReg,
+           const CPURegister& dst2 = NoReg, const CPURegister& dst3 = NoReg);
+
+  // Alternative forms of Push and Pop, taking a RegList or CPURegList that
+  // specifies the registers that are to be pushed or popped. Higher-numbered
+  // registers are associated with higher memory addresses (as in the A32 push
+  // and pop instructions).
+  //
+  // (Push|Pop)SizeRegList allow you to specify the register size as a
+  // parameter. Only kXRegSize, kWRegSize, kDRegSize and kSRegSize are
+  // supported.
+  //
+  // Otherwise, (Push|Pop)(CPU|X|W|D|S)RegList is preferred.
+  void PushCPURegList(CPURegList registers);
+  void PopCPURegList(CPURegList registers);
+
+  inline void PushSizeRegList(RegList registers, unsigned reg_size,
+      CPURegister::RegisterType type = CPURegister::kRegister) {
+    PushCPURegList(CPURegList(type, reg_size, registers));
+  }
+  inline void PopSizeRegList(RegList registers, unsigned reg_size,
+      CPURegister::RegisterType type = CPURegister::kRegister) {
+    PopCPURegList(CPURegList(type, reg_size, registers));
+  }
+  inline void PushXRegList(RegList regs) {
+    PushSizeRegList(regs, kXRegSize);
+  }
+  inline void PopXRegList(RegList regs) {
+    PopSizeRegList(regs, kXRegSize);
+  }
+  inline void PushWRegList(RegList regs) {
+    PushSizeRegList(regs, kWRegSize);
+  }
+  inline void PopWRegList(RegList regs) {
+    PopSizeRegList(regs, kWRegSize);
+  }
+  inline void PushDRegList(RegList regs) {
+    PushSizeRegList(regs, kDRegSize, CPURegister::kFPRegister);
+  }
+  inline void PopDRegList(RegList regs) {
+    PopSizeRegList(regs, kDRegSize, CPURegister::kFPRegister);
+  }
+  inline void PushSRegList(RegList regs) {
+    PushSizeRegList(regs, kSRegSize, CPURegister::kFPRegister);
+  }
+  inline void PopSRegList(RegList regs) {
+    PopSizeRegList(regs, kSRegSize, CPURegister::kFPRegister);
+  }
+
+  // Push the specified register 'count' times.
+  void PushMultipleTimes(int count, Register src);
+
+  // This is a convenience method for pushing a single Handle<Object>.
+  inline void Push(Handle<Object> handle);
+  void Push(Smi* smi) { Push(Handle<Smi>(smi, isolate())); }
+
+  // Aliases of Push and Pop, required for V8 compatibility.
+  inline void push(Register src) {
+    Push(src);
+  }
+  inline void pop(Register dst) {
+    Pop(dst);
+  }
+
+  // Poke 'src' onto the stack. The offset is in bytes.
+  //
+  // If the current stack pointer (according to StackPointer()) is csp, then
+  // csp must be aligned to 16 bytes.
+  void Poke(const Register& src, const Operand& offset);
+
+  // Peek at a value on the stack, and put it in 'dst'. The offset is in bytes.
+  //
+  // If the current stack pointer (according to StackPointer()) is csp, then
+  // csp must be aligned to 16 bytes.
+  void Peek(const Register& dst, const Operand& offset);
+
+  // Claim or drop stack space without actually accessing memory.
+  //
+  // In debug mode, both of these will write invalid data into the claimed or
+  // dropped space.
+  //
+  // If the current stack pointer (according to StackPointer()) is csp, then it
+  // must be aligned to 16 bytes and the size claimed or dropped must be a
+  // multiple of 16 bytes.
+  //
+  // Note that unit_size must be specified in bytes. For variants which take a
+  // Register count, the unit size must be a power of two.
+  inline void Claim(uint64_t count, uint64_t unit_size = kXRegSizeInBytes);
+  inline void Claim(const Register& count,
+                    uint64_t unit_size = kXRegSizeInBytes);
+  inline void Drop(uint64_t count, uint64_t unit_size = kXRegSizeInBytes);
+  inline void Drop(const Register& count,
+                   uint64_t unit_size = kXRegSizeInBytes);
+
+  // Variants of Claim and Drop, where the 'count' parameter is a SMI held in a
+  // register.
+  inline void ClaimBySMI(const Register& count_smi,
+                         uint64_t unit_size = kXRegSizeInBytes);
+  inline void DropBySMI(const Register& count_smi,
+                        uint64_t unit_size = kXRegSizeInBytes);
+
+  // Compare a register with an operand, and branch to label depending on the
+  // condition. May corrupt the status flags.
+  inline void CompareAndBranch(const Register& lhs,
+                               const Operand& rhs,
+                               Condition cond,
+                               Label* label);
+
+  // Test the bits of register defined by bit_pattern, and branch if ANY of
+  // those bits are set. May corrupt the status flags.
+  inline void TestAndBranchIfAnySet(const Register& reg,
+                                    const uint64_t bit_pattern,
+                                    Label* label);
+
+  // Test the bits of register defined by bit_pattern, and branch if ALL of
+  // those bits are clear (ie. not set.) May corrupt the status flags.
+  inline void TestAndBranchIfAllClear(const Register& reg,
+                                      const uint64_t bit_pattern,
+                                      Label* label);
+
+  // Insert one or more instructions into the instruction stream that encode
+  // some caller-defined data. The instructions used will be executable with no
+  // side effects.
+  inline void InlineData(uint64_t data);
+
+  // Insert an instrumentation enable marker into the instruction stream.
+  inline void EnableInstrumentation();
+
+  // Insert an instrumentation disable marker into the instruction stream.
+  inline void DisableInstrumentation();
+
+  // Insert an instrumentation event marker into the instruction stream. These
+  // will be picked up by the instrumentation system to annotate an instruction
+  // profile. The argument marker_name must be a printable two character string;
+  // it will be encoded in the event marker.
+  inline void AnnotateInstrumentation(const char* marker_name);
+
+  // If emit_debug_code() is true, emit a run-time check to ensure that
+  // StackPointer() does not point below the system stack pointer.
+  //
+  // Whilst it is architecturally legal for StackPointer() to point below csp,
+  // it can be evidence of a potential bug because the ABI forbids accesses
+  // below csp.
+  //
+  // If emit_debug_code() is false, this emits no code.
+  //
+  // If StackPointer() is the system stack pointer, this emits no code.
+  void AssertStackConsistency();
+
+  // Preserve the callee-saved registers (as defined by AAPCS64).
+  //
+  // Higher-numbered registers are pushed before lower-numbered registers, and
+  // thus get higher addresses.
+  // Floating-point registers are pushed before general-purpose registers, and
+  // thus get higher addresses.
+  //
+  // Note that registers are not checked for invalid values. Use this method
+  // only if you know that the GC won't try to examine the values on the stack.
+  //
+  // This method must not be called unless the current stack pointer (as set by
+  // SetStackPointer) is the system stack pointer (csp), and is aligned to
+  // ActivationFrameAlignment().
+  void PushCalleeSavedRegisters();
+
+  // Restore the callee-saved registers (as defined by AAPCS64).
+  //
+  // Higher-numbered registers are popped after lower-numbered registers, and
+  // thus come from higher addresses.
+  // Floating-point registers are popped after general-purpose registers, and
+  // thus come from higher addresses.
+  //
+  // This method must not be called unless the current stack pointer (as set by
+  // SetStackPointer) is the system stack pointer (csp), and is aligned to
+  // ActivationFrameAlignment().
+  void PopCalleeSavedRegisters();
+
+  // Set the current stack pointer, but don't generate any code.
+  inline void SetStackPointer(const Register& stack_pointer) {
+    ASSERT(!AreAliased(stack_pointer, Tmp0(), Tmp1()));
+    sp_ = stack_pointer;
+  }
+
+  // Return the current stack pointer, as set by SetStackPointer.
+  inline const Register& StackPointer() const {
+    return sp_;
+  }
+
+  // Align csp for a frame, as per ActivationFrameAlignment, and make it the
+  // current stack pointer.
+  inline void AlignAndSetCSPForFrame() {
+    int sp_alignment = ActivationFrameAlignment();
+    // AAPCS64 mandates at least 16-byte alignment.
+    ASSERT(sp_alignment >= 16);
+    ASSERT(IsPowerOf2(sp_alignment));
+    Bic(csp, StackPointer(), sp_alignment - 1);
+    SetStackPointer(csp);
+  }
+
+  // Push the system stack pointer (csp) down to allow the same to be done to
+  // the current stack pointer (according to StackPointer()). This must be
+  // called _before_ accessing the memory.
+  //
+  // This is necessary when pushing or otherwise adding things to the stack, to
+  // satisfy the AAPCS64 constraint that the memory below the system stack
+  // pointer is not accessed.
+  //
+  // This method asserts that StackPointer() is not csp, since the call does
+  // not make sense in that context.
+  //
+  // TODO(jbramley): Currently, this method can only accept values of 'space'
+  // that can be encoded in one instruction. Refer to the implementation for
+  // details.
+  inline void BumpSystemStackPointer(const Operand& space);
+
+  // Helpers ------------------------------------------------------------------
+  // Root register.
+  inline void InitializeRootRegister();
+
+  // Load an object from the root table.
+  void LoadRoot(Register destination,
+                Heap::RootListIndex index);
+  // Store an object to the root table.
+  void StoreRoot(Register source,
+                 Heap::RootListIndex index);
+
+  // Load both TrueValue and FalseValue roots.
+  void LoadTrueFalseRoots(Register true_root, Register false_root);
+
+  void LoadHeapObject(Register dst, Handle<HeapObject> object);
+
+  void LoadObject(Register result, Handle<Object> object) {
+    AllowDeferredHandleDereference heap_object_check;
+    if (object->IsHeapObject()) {
+      LoadHeapObject(result, Handle<HeapObject>::cast(object));
+    } else {
+      Mov(result, Operand(object));
+    }
+  }
+
+  static int SafepointRegisterStackIndex(int reg_code);
+
+  void CheckForInvalidValuesInCalleeSavedRegs(RegList list);
+
+  // This is required for compatibility with architecture independant code.
+  // Remove if not needed.
+  inline void Move(Register dst, Register src) { Mov(dst, src); }
+
+  void LoadInstanceDescriptors(Register map,
+                               Register descriptors);
+  void EnumLengthUntagged(Register dst, Register map);
+  void EnumLengthSmi(Register dst, Register map);
+  void NumberOfOwnDescriptors(Register dst, Register map);
+
+  template<typename Field>
+  void DecodeField(Register reg) {
+    static const uint64_t shift = Field::kShift + kSmiShift;
+    static const uint64_t setbits = CountSetBits(Field::kMask, 32);
+    Ubfx(reg, reg, shift, setbits);
+  }
+
+  // ---- SMI and Number Utilities ----
+
+  inline void SmiTag(Register dst, Register src);
+  inline void SmiTag(Register smi);
+  inline void SmiUntag(Register dst, Register src);
+  inline void SmiUntag(Register smi);
+  inline void SmiUntagToDouble(FPRegister dst,
+                               Register src,
+                               UntagMode mode = kNotSpeculativeUntag);
+  inline void SmiUntagToFloat(FPRegister dst,
+                              Register src,
+                              UntagMode mode = kNotSpeculativeUntag);
+
+  // Compute the absolute value of 'smi' and leave the result in 'smi'
+  // register. If 'smi' is the most negative SMI, the absolute value cannot
+  // be represented as a SMI and a jump to 'slow' is done.
+  void SmiAbs(Register smi, Register scratch, Label *slow);
+
+  inline void JumpIfSmi(Register value,
+                        Label* smi_label,
+                        Label* not_smi_label = NULL);
+  inline void JumpIfNotSmi(Register value, Label* not_smi_label);
+  inline void JumpIfBothSmi(Register value1,
+                            Register value2,
+                            Label* both_smi_label,
+                            Label* not_smi_label = NULL);
+  inline void JumpIfEitherSmi(Register value1,
+                              Register value2,
+                              Label* either_smi_label,
+                              Label* not_smi_label = NULL);
+  inline void JumpIfEitherNotSmi(Register value1,
+                                 Register value2,
+                                 Label* not_smi_label);
+  inline void JumpIfBothNotSmi(Register value1,
+                               Register value2,
+                               Label* not_smi_label);
+
+  // Abort execution if argument is a smi, enabled via --debug-code.
+  void AssertNotSmi(Register object,
+                    const char* fail_message = "Operand is a smi");
+  void AssertSmi(Register object,
+                 const char* fail_message = "Operand is not a smi");
+
+  // Abort execution if argument is not a name, enabled via --debug-code.
+  void AssertName(Register object);
+
+  // Abort execution if argument is not a string, enabled via --debug-code.
+  void AssertString(Register object);
+
+  // Abort execution if argument is not the root value with the given index,
+  // enabled via --debug-code.
+  void AssertRootValue(Register src,
+                       Heap::RootListIndex root_value_index,
+                       const char* message);
+
+  void JumpForHeapNumber(Register object,
+                         Register heap_number_map,
+                         Label* on_heap_number,
+                         Label* on_not_heap_number = NULL);
+  void JumpIfHeapNumber(Register object,
+                        Label* on_heap_number,
+                        Register heap_number_map = NoReg);
+  void JumpIfNotHeapNumber(Register object,
+                           Label* on_not_heap_number,
+                           Register heap_number_map = NoReg);
+
+  // Saturate a signed 32-bit integer in input to an unsigned 8-bit integer in
+  // output.
+  void ClampInt32ToUint8(Register in_out);
+  void ClampInt32ToUint8(Register output, Register input);
+
+  // Saturate a double in input to an unsigned 8-bit integer in output.
+  void ClampDoubleToUint8(Register output,
+                          DoubleRegister input,
+                          DoubleRegister dbl_scratch);
+
+  // Try to convert a double to a signed 32-bit int.
+  // This succeeds if the result compares equal to the input, so inputs of -0.0
+  // are converted to 0 and handled as a success.
+  void TryConvertDoubleToInt32(Register as_int,
+                               FPRegister value,
+                               FPRegister scratch_d,
+                               Label* on_successful_conversion,
+                               Label* on_failed_conversion = NULL) {
+    ASSERT(as_int.Is32Bits());
+    TryConvertDoubleToInt(as_int, value, scratch_d, on_successful_conversion,
+                          on_failed_conversion);
+  }
+
+  // Try to convert a double to a signed 64-bit int.
+  // This succeeds if the result compares equal to the input, so inputs of -0.0
+  // are converted to 0 and handled as a success.
+  void TryConvertDoubleToInt64(Register as_int,
+                               FPRegister value,
+                               FPRegister scratch_d,
+                               Label* on_successful_conversion,
+                               Label* on_failed_conversion = NULL) {
+    ASSERT(as_int.Is64Bits());
+    TryConvertDoubleToInt(as_int, value, scratch_d, on_successful_conversion,
+                          on_failed_conversion);
+  }
+
+  // ---- Object Utilities ----
+
+  // Copy fields from 'src' to 'dst', where both are tagged objects.
+  // The 'temps' list is a list of X registers which can be used for scratch
+  // values. The temps list must include at least one register, and it must not
+  // contain Tmp0() or Tmp1().
+  //
+  // Currently, CopyFields cannot make use of more than three registers from
+  // the 'temps' list.
+  //
+  // As with several MacroAssembler methods, Tmp0() and Tmp1() will be used.
+  void CopyFields(Register dst, Register src, CPURegList temps, unsigned count);
+
+  // Copies a number of bytes from src to dst. All passed registers are
+  // clobbered. On exit src and dst will point to the place just after where the
+  // last byte was read or written and length will be zero. Hint may be used to
+  // determine which is the most efficient algorithm to use for copying.
+  void CopyBytes(Register dst,
+                 Register src,
+                 Register length,
+                 Register scratch,
+                 CopyHint hint = kCopyUnknown);
+
+  // Initialize fields with filler values. Fields starting at start_offset not
+  // including end_offset are overwritten with the value in filler. At the end
+  // of the loop, start_offset takes the value of end_offset.
+  void InitializeFieldsWithFiller(Register start_offset,
+                                  Register end_offset,
+                                  Register filler);
+
+  // ---- String Utilities ----
+
+
+  // Jump to label if either object is not a sequential ASCII string.
+  // Optionally perform a smi check on the objects first.
+  void JumpIfEitherIsNotSequentialAsciiStrings(
+      Register first,
+      Register second,
+      Register scratch1,
+      Register scratch2,
+      Label* failure,
+      SmiCheckType smi_check = DO_SMI_CHECK);
+
+  // Check if instance type is sequential ASCII string and jump to label if
+  // it is not.
+  void JumpIfInstanceTypeIsNotSequentialAscii(Register type,
+                                              Register scratch,
+                                              Label* failure);
+
+  // Checks if both instance types are sequential ASCII strings and jumps to
+  // label if either is not.
+  void JumpIfEitherInstanceTypeIsNotSequentialAscii(
+      Register first_object_instance_type,
+      Register second_object_instance_type,
+      Register scratch1,
+      Register scratch2,
+      Label* failure);
+
+  // Checks if both instance types are sequential ASCII strings and jumps to
+  // label if either is not.
+  void JumpIfBothInstanceTypesAreNotSequentialAscii(
+      Register first_object_instance_type,
+      Register second_object_instance_type,
+      Register scratch1,
+      Register scratch2,
+      Label* failure);
+
+  // ---- Calling / Jumping helpers ----
+
+  // This is required for compatibility in architecture indepenedant code.
+  inline void jmp(Label* L) { B(L); }
+
+  // Passes thrown value to the handler of top of the try handler chain.
+  // Register value must be x0.
+  void Throw(Register value,
+             Register scratch1,
+             Register scratch2,
+             Register scratch3,
+             Register scratch4);
+
+  // Propagates an uncatchable exception to the top of the current JS stack's
+  // handler chain. Register value must be x0.
+  void ThrowUncatchable(Register value,
+                        Register scratch1,
+                        Register scratch2,
+                        Register scratch3,
+                        Register scratch4);
+
+  void CallStub(CodeStub* stub, TypeFeedbackId ast_id = TypeFeedbackId::None());
+  void TailCallStub(CodeStub* stub);
+
+  void CallRuntime(const Runtime::Function* f, int num_arguments);
+  void CallRuntime(Runtime::FunctionId fid, int num_arguments);
+  void TailCallRuntime(Runtime::FunctionId fid,
+                       int num_arguments,
+                       int result_size);
+  void CallRuntimeSaveDoubles(Runtime::FunctionId id);
+
+  int ActivationFrameAlignment();
+
+  // Calls a C function.
+  // The called function is not allowed to trigger a
+  // garbage collection, since that might move the code and invalidate the
+  // return address (unless this is somehow accounted for by the called
+  // function).
+  void CallCFunction(ExternalReference function,
+                     int num_reg_arguments);
+  void CallCFunction(ExternalReference function,
+                     int num_reg_arguments,
+                     int num_double_arguments);
+  void CallCFunction(Register function,
+                     int num_reg_arguments,
+                     int num_double_arguments);
+
+  // Calls an API function. Allocates HandleScope, extracts returned value
+  // from handle and propagates exceptions.
+  // 'stack_space' is the space to be unwound on exit (includes the call JS
+  // arguments space and the additional space allocated for the fast call).
+  // 'spill_offset' is the offset from the stack pointer where
+  // CallApiFunctionAndReturn can spill registers.
+  void CallApiFunctionAndReturn(ExternalReference function,
+                                int stack_space,
+                                int spill_offset,
+                                bool returns_handle,
+                                int return_value_offset_from_fp);
+
+  // The number of register that CallApiFunctionAndReturn will need to save on
+  // the stack. The space for these registers need to be allocated in the
+  // ExitFrame before calling CallApiFunctionAndReturn.
+  static const int kCallApiFunctionSpillSpace = 4;
+
+  // Jump to a runtime routine.
+  void JumpToExternalReference(const ExternalReference& builtin);
+  // Tail call of a runtime routine (jump).
+  // Like JumpToExternalReference, but also takes care of passing the number
+  // of parameters.
+  void TailCallExternalReference(const ExternalReference& ext,
+                                 int num_arguments,
+                                 int result_size);
+  void CallExternalReference(const ExternalReference& ext,
+                             int num_arguments);
+
+
+  // Invoke specified builtin JavaScript function. Adds an entry to
+  // the unresolved list if the name does not resolve.
+  void InvokeBuiltin(Builtins::JavaScript id,
+                     InvokeFlag flag,
+                     const CallWrapper& call_wrapper = NullCallWrapper());
+
+  // Store the code object for the given builtin in the target register and
+  // setup the function in x1.
+  // TODO(all): Can we use another register than x1?
+  void GetBuiltinEntry(Register target, Builtins::JavaScript id);
+
+  // Store the function for the given builtin in the target register.
+  void GetBuiltinFunction(Register target, Builtins::JavaScript id);
+
+  void Jump(Register target);
+  void Jump(Address target, RelocInfo::Mode rmode);
+  void Jump(Handle<Code> code, RelocInfo::Mode rmode);
+  void Jump(intptr_t target, RelocInfo::Mode rmode);
+
+  void Call(Register target);
+  void Call(Label* target);
+  void Call(Address target, RelocInfo::Mode rmode);
+  void Call(Handle<Code> code,
+            RelocInfo::Mode rmode = RelocInfo::CODE_TARGET,
+            TypeFeedbackId ast_id = TypeFeedbackId::None());
+
+  // For every Call variant, there is a matching CallSize function that returns
+  // the size (in bytes) of the call sequence.
+  static int CallSize(Register target);
+  static int CallSize(Label* target);
+  static int CallSize(Address target, RelocInfo::Mode rmode);
+  static int CallSize(Handle<Code> code,
+                      RelocInfo::Mode rmode = RelocInfo::CODE_TARGET,
+                      TypeFeedbackId ast_id = TypeFeedbackId::None());
+
+  // Set up call kind marking in x5. The method takes x5 as an
+  // explicit first parameter to make the code more readable at the
+  // call sites.
+  void SetCallKind(Register dst, CallKind kind);
+
+  // Registers used through the invocation chain are hard-coded.
+  // We force passing the parameters to ensure the contracts are correctly
+  // honoured by the caller.
+  // 'function' must be x1.
+  // 'actual' must use an immediate or x0.
+  // 'expected' must use an immediate or x2.
+  // 'call_kind' must be x5.
+  void InvokePrologue(const ParameterCount& expected,
+                      const ParameterCount& actual,
+                      Handle<Code> code_constant,
+                      Register code_reg,
+                      Label* done,
+                      InvokeFlag flag,
+                      bool* definitely_mismatches,
+                      const CallWrapper& call_wrapper,
+                      CallKind call_kind);
+  void InvokeCode(Register code,
+                  const ParameterCount& expected,
+                  const ParameterCount& actual,
+                  InvokeFlag flag,
+                  const CallWrapper& call_wrapper,
+                  CallKind call_kind);
+  void InvokeCode(Handle<Code> code,
+                  const ParameterCount& expected,
+                  const ParameterCount& actual,
+                  RelocInfo::Mode rmode,
+                  InvokeFlag flag,
+                  CallKind call_kind);
+  // Invoke the JavaScript function in the given register.
+  // Changes the current context to the context in the function before invoking.
+  void InvokeFunction(Register function,
+                      const ParameterCount& actual,
+                      InvokeFlag flag,
+                      const CallWrapper& call_wrapper,
+                      CallKind call_kind);
+  void InvokeFunction(Handle<JSFunction> function,
+                      const ParameterCount& expected,
+                      const ParameterCount& actual,
+                      InvokeFlag flag,
+                      const CallWrapper& call_wrapper,
+                      CallKind call_kind,
+                      Register function_reg = NoReg);
+
+
+  // ---- Floating point helpers ----
+
+  enum ECMA262ToInt32Result {
+    // Provide an untagged int32_t which can be read using result.W(). That is,
+    // the upper 32 bits of result are undefined.
+    INT32_IN_W,
+
+    // Provide an untagged int32_t which can be read using the 64-bit result
+    // register. The int32_t result is sign-extended.
+    INT32_IN_X,
+
+    // Tag the int32_t result as a smi.
+    SMI
+  };
+
+  // Applies ECMA-262 ToInt32 (see section 9.5) to a double value.
+  void ECMA262ToInt32(Register result,
+                      DoubleRegister input,
+                      Register scratch1,
+                      Register scratch2,
+                      ECMA262ToInt32Result format = INT32_IN_X);
+
+  // As ECMA262ToInt32, but operate on a HeapNumber.
+  void HeapNumberECMA262ToInt32(Register result,
+                                Register heap_number,
+                                Register scratch1,
+                                Register scratch2,
+                                DoubleRegister double_scratch,
+                                ECMA262ToInt32Result format = INT32_IN_X);
+
+  // ---- Code generation helpers ----
+
+  // Generate a runtime call or jump for a unary operation.
+  // Caller-saved registers are not preserved.
+  // Expected on entry:
+  // x0: operand
+  // Returns with:
+  // x0: result
+  // sp on exit == sp before entry.
+  void GenerateNumberUnaryOperation(Token::Value op, InvokeFlag flag);
+
+  // Generate a runtime call or jump for a binary operation.
+  // Caller-saved registers are not preserved.
+  // Expected on entry:
+  // x0: right
+  // x1: left
+  // Returns with:
+  // x0: result
+  // sp on exit == sp before entry.
+  void GenerateNumberNumberBinaryOperation(Token::Value op, InvokeFlag flag);
+
+  void set_generating_stub(bool value) { generating_stub_ = value; }
+  bool generating_stub() const { return generating_stub_; }
+  void set_allow_stub_calls(bool value) { allow_stub_calls_ = value; }
+  bool allow_stub_calls() const { return allow_stub_calls_; }
+#if DEBUG
+  void set_allow_macro_instructions(bool value) {
+    allow_macro_instructions_ = value;
+  }
+  bool allow_macro_instructions() const { return allow_macro_instructions_; }
+#endif
+  void set_use_real_aborts(bool value) { use_real_aborts_ = value; }
+  bool use_real_aborts() const { return use_real_aborts_; }
+  void set_has_frame(bool value) { has_frame_ = value; }
+  bool has_frame() const { return has_frame_; }
+  bool AllowThisStubCall(CodeStub* stub);
+
+#ifdef ENABLE_DEBUGGER_SUPPORT
+  // ---------------------------------------------------------------------------
+  // Debugger Support
+
+  void DebugBreak();
+#endif
+  // ---------------------------------------------------------------------------
+  // Exception handling
+
+  // Push a new try handler and link into try handler chain.
+  void PushTryHandler(StackHandler::Kind kind, int handler_index);
+
+  // Unlink the stack handler on top of the stack from the try handler chain.
+  // Must preserve the result register.
+  void PopTryHandler();
+
+
+  // ---------------------------------------------------------------------------
+  // Allocation support
+
+  // Allocate an object in new space or old pointer space. The object_size is
+  // specified either in bytes or in words if the allocation flag SIZE_IN_WORDS
+  // is passed. The allocated object is returned in result.
+  //
+  // If the new space is exhausted control continues at the gc_required label.
+  // In this case, the result and scratch registers may still be clobbered.
+  // If flags includes TAG_OBJECT, the result is tagged as as a heap object.
+  void Allocate(Register object_size,
+                Register result,
+                Register scratch1,
+                Register scratch2,
+                Label* gc_required,
+                AllocationFlags flags);
+
+  void Allocate(int object_size,
+                Register result,
+                Register scratch1,
+                Register scratch2,
+                Label* gc_required,
+                AllocationFlags flags);
+
+  // Undo allocation in new space. The object passed and objects allocated after
+  // it will no longer be allocated. The caller must make sure that no pointers
+  // are left to the object(s) no longer allocated as they would be invalid when
+  // allocation is undone.
+  void UndoAllocationInNewSpace(Register object, Register scratch);
+
+  void AllocateTwoByteString(Register result,
+                             Register length,
+                             Register scratch1,
+                             Register scratch2,
+                             Register scratch3,
+                             Label* gc_required);
+  void AllocateAsciiString(Register result,
+                           Register length,
+                           Register scratch1,
+                           Register scratch2,
+                           Register scratch3,
+                           Label* gc_required);
+  void AllocateTwoByteConsString(Register result,
+                                 Register length,
+                                 Register scratch1,
+                                 Register scratch2,
+                                 Label* gc_required);
+  void AllocateAsciiConsString(Register result,
+                               Register length,
+                               Register scratch1,
+                               Register scratch2,
+                               Label* gc_required);
+  void AllocateTwoByteSlicedString(Register result,
+                                   Register length,
+                                   Register scratch1,
+                                   Register scratch2,
+                                   Label* gc_required);
+  void AllocateAsciiSlicedString(Register result,
+                                 Register length,
+                                 Register scratch1,
+                                 Register scratch2,
+                                 Label* gc_required);
+
+  // Allocates a heap number or jumps to the gc_required label if the young
+  // space is full and a scavenge is needed.
+  // All registers are clobbered.
+  // If no heap_number_map register is provided, the function will take care of
+  // loading it.
+  void AllocateHeapNumber(Register result,
+                          Label* gc_required,
+                          Register scratch1,
+                          Register scratch2,
+                          Register heap_number_map = NoReg);
+  void AllocateHeapNumberWithValue(Register result,
+                                   DoubleRegister value,
+                                   Label* gc_required,
+                                   Register scratch1,
+                                   Register scratch2,
+                                   Register heap_number_map = NoReg);
+
+  // ---------------------------------------------------------------------------
+  // Support functions.
+
+  // Try to get function prototype of a function and puts the value in the
+  // result register. Checks that the function really is a function and jumps
+  // to the miss label if the fast checks fail. The function register will be
+  // untouched; the other registers may be clobbered.
+  enum BoundFunctionAction {
+    kMissOnBoundFunction,
+    kDontMissOnBoundFunction
+  };
+
+  void TryGetFunctionPrototype(Register function,
+                               Register result,
+                               Register scratch,
+                               Label* miss,
+                               BoundFunctionAction action =
+                                 kDontMissOnBoundFunction);
+
+  // Compare object type for heap object.  heap_object contains a non-Smi
+  // whose object type should be compared with the given type.  This both
+  // sets the flags and leaves the object type in the type_reg register.
+  // It leaves the map in the map register (unless the type_reg and map register
+  // are the same register).  It leaves the heap object in the heap_object
+  // register unless the heap_object register is the same register as one of the
+  // other registers.
+  void CompareObjectType(Register heap_object,
+                         Register map,
+                         Register type_reg,
+                         InstanceType type);
+
+
+  // Compare object type for heap object, and branch if equal (or not.)
+  // heap_object contains a non-Smi whose object type should be compared with
+  // the given type.  This both sets the flags and leaves the object type in
+  // the type_reg register. It leaves the map in the map register (unless the
+  // type_reg and map register are the same register).  It leaves the heap
+  // object in the heap_object register unless the heap_object register is the
+  // same register as one of the other registers.
+  void JumpIfObjectType(Register object,
+                        Register map,
+                        Register type_reg,
+                        InstanceType type,
+                        Label* if_cond_pass,
+                        Condition cond = eq);
+
+  void JumpIfNotObjectType(Register object,
+                           Register map,
+                           Register type_reg,
+                           InstanceType type,
+                           Label* if_not_object);
+
+  // Compare instance type in a map.  map contains a valid map object whose
+  // object type should be compared with the given type.  This both
+  // sets the flags and leaves the object type in the type_reg register.
+  void CompareInstanceType(Register map,
+                           Register type_reg,
+                           InstanceType type);
+
+  // Compare an object's map with the specified map and its transitioned
+  // elements maps if mode is ALLOW_ELEMENT_TRANSITION_MAPS. Condition flags are
+  // set with result of map compare. If multiple map compares are required, the
+  // compare sequences branches to early_success.
+  void CompareMap(Register obj,
+                  Register scratch,
+                  Handle<Map> map,
+                  Label* early_success = NULL);
+
+  // As above, but the map of the object is already loaded into the register
+  // which is preserved by the code generated.
+  void CompareMap(Register obj_map,
+                  Handle<Map> map,
+                  Label* early_success = NULL);
+
+  // Check if the map of an object is equal to a specified map and branch to
+  // label if not. Skip the smi check if not required (object is known to be a
+  // heap object). If mode is ALLOW_ELEMENT_TRANSITION_MAPS, then also match
+  // against maps that are ElementsKind transition maps of the specified map.
+  void CheckMap(Register obj,
+                Register scratch,
+                Handle<Map> map,
+                Label* fail,
+                SmiCheckType smi_check_type);
+
+
+  void CheckMap(Register obj,
+                Register scratch,
+                Heap::RootListIndex index,
+                Label* fail,
+                SmiCheckType smi_check_type);
+
+  // As above, but the map of the object is already loaded into obj_map, and is
+  // preserved.
+  void CheckMap(Register obj_map,
+                Handle<Map> map,
+                Label* fail,
+                SmiCheckType smi_check_type);
+
+  // Check if the map of an object is equal to a specified map and branch to a
+  // specified target if equal. Skip the smi check if not required (object is
+  // known to be a heap object)
+  void DispatchMap(Register obj,
+                   Register scratch,
+                   Handle<Map> map,
+                   Handle<Code> success,
+                   SmiCheckType smi_check_type);
+
+  // Test the bitfield of the heap object map with mask and set the condition
+  // flags. The object register is preserved.
+  void TestMapBitfield(Register object, uint64_t mask);
+
+  // Load the elements kind field of an object, and return it in the result
+  // register.
+  void LoadElementsKind(Register result, Register object);
+
+  // Compare the object in a register to a value from the root list.
+  // Uses the Tmp0() register as scratch.
+  void CompareRoot(const Register& obj, Heap::RootListIndex index);
+
+  // Compare the object in a register to a value and jump if they are equal.
+  void JumpIfRoot(const Register& obj,
+                  Heap::RootListIndex index,
+                  Label* if_equal);
+
+  // Compare the object in a register to a value and jump if they are not equal.
+  void JumpIfNotRoot(const Register& obj,
+                     Heap::RootListIndex index,
+                     Label* if_not_equal);
+
+  // Load and check the instance type of an object for being a unique name.
+  // Loads the type into the second argument register.
+  // The object and type arguments can be the same register; in that case it
+  // will be overwritten with the type.
+  // Fall-through if the object was a string and jump on fail otherwise.
+  inline void IsObjectNameType(Register object, Register type, Label* fail);
+
+  inline void IsObjectJSObjectType(Register heap_object,
+                                   Register map,
+                                   Register scratch,
+                                   Label* fail);
+
+  // Check the instance type in the given map to see if it corresponds to a
+  // JS object type. Jump to the fail label if this is not the case and fall
+  // through otherwise. However if fail label is NULL, no branch will be
+  // performed and the flag will be updated. You can test the flag for "le"
+  // condition to test if it is a valid JS object type.
+  inline void IsInstanceJSObjectType(Register map,
+                                     Register scratch,
+                                     Label* fail);
+
+  // Load and check the instance type of an object for being a string.
+  // Loads the type into the second argument register.
+  // The object and type arguments can be the same register; in that case it
+  // will be overwritten with the type.
+  // Jumps to not_string or string appropriate. If the appropriate label is
+  // NULL, fall through.
+  inline void IsObjectJSStringType(Register object, Register type,
+                                   Label* not_string, Label* string = NULL);
+
+  // Compare the contents of a register with an operand, and branch to true,
+  // false or fall through, depending on condition.
+  void CompareAndSplit(const Register& lhs,
+                       const Operand& rhs,
+                       Condition cond,
+                       Label* if_true,
+                       Label* if_false,
+                       Label* fall_through);
+
+  // Test the bits of register defined by bit_pattern, and branch to
+  // if_any_set, if_all_clear or fall_through accordingly.
+  void TestAndSplit(const Register& reg,
+                    uint64_t bit_pattern,
+                    Label* if_all_clear,
+                    Label* if_any_set,
+                    Label* fall_through);
+
+  // Check if a map for a JSObject indicates that the object has fast elements.
+  // Jump to the specified label if it does not.
+  void CheckFastElements(Register map,
+                         Register scratch,
+                         Label* fail);
+
+  // Check if a map for a JSObject indicates that the object can have both smi
+  // and HeapObject elements.  Jump to the specified label if it does not.
+  void CheckFastObjectElements(Register map,
+                               Register scratch,
+                               Label* fail);
+
+  // Check if a map for a JSObject indicates that the object has fast smi only
+  // elements. Jump to the specified label if it does not.
+  void CheckFastSmiElements(Register map, Register scratch, Label* fail);
+
+  // Check to see if number can be stored as a double in FastDoubleElements.
+  // If it can, store it at the index specified by key_reg in the array,
+  // otherwise jump to fail.
+  void StoreNumberToDoubleElements(Register value_reg,
+                                   Register key_reg,
+                                   Register elements_reg,
+                                   Register scratch1,
+                                   FPRegister fpscratch1,
+                                   FPRegister fpscratch2,
+                                   Label* fail);
+
+  // Picks out an array index from the hash field.
+  // Register use:
+  //   hash - holds the index's hash. Clobbered.
+  //   index - holds the overwritten index on exit.
+  void IndexFromHash(Register hash, Register index);
+
+  // ---------------------------------------------------------------------------
+  // Inline caching support.
+
+  // Generate code for checking access rights - used for security checks
+  // on access to global objects across environments. The holder register
+  // is left untouched, whereas both scratch registers are clobbered.
+  void CheckAccessGlobalProxy(Register holder_reg,
+                              Register scratch,
+                              Label* miss);
+
+  // Hash the interger value in 'key' register.
+  // It uses the same algorithm as ComputeIntegerHash in utils.h.
+  void GetNumberHash(Register key, Register scratch);
+
+  // Load value from the dictionary.
+  //
+  // elements - holds the slow-case elements of the receiver on entry.
+  //            Unchanged unless 'result' is the same register.
+  //
+  // key      - holds the smi key on entry.
+  //            Unchanged unless 'result' is the same register.
+  //
+  // result   - holds the result on exit if the load succeeded.
+  //            Allowed to be the same as 'key' or 'result'.
+  //            Unchanged on bailout so 'key' or 'result' can be used
+  //            in further computation.
+  void LoadFromNumberDictionary(Label* miss,
+                                Register elements,
+                                Register key,
+                                Register result,
+                                Register scratch0,
+                                Register scratch1,
+                                Register scratch2,
+                                Register scratch3);
+
+  // ---------------------------------------------------------------------------
+  // Frames.
+
+  // Activation support.
+  // Note that Tmp0() and Tmp1() are used as a scratch registers. This is safe
+  // because these methods are not used in Crankshaft.
+  void EnterFrame(StackFrame::Type type);
+  void LeaveFrame(StackFrame::Type type);
+
+  // Returns map with validated enum cache in object register.
+  void CheckEnumCache(Register object,
+                      Register null_value,
+                      Register scratch0,
+                      Register scratch1,
+                      Register scratch2,
+                      Register scratch3,
+                      Label* call_runtime);
+
+  // AllocationSiteInfo support. Arrays may have an associated
+  // AllocationSiteInfo object that can be checked for in order to pretransition
+  // to another type.
+  // On entry, receiver should point to the array object.
+  // If allocation info is present, the Z flag is set (so that the eq
+  // condition will pass).
+  void TestJSArrayForAllocationSiteInfo(Register receiver,
+                                        Register scratch1,
+                                        Register scratch2);
+
+  // Enter exit frame. Exit frames are used when calling C code from generated
+  // (JavaScript) code.
+  //
+  // The stack pointer must be jssp on entry, and will be set to csp by this
+  // function. The frame pointer is also configured, but the only other
+  // registers modified by this function are the provided scratch register, and
+  // jssp.
+  //
+  // The 'extra_space' argument can be used to allocate some space in the exit
+  // frame that will be ignored by the GC. This space will be reserved in the
+  // bottom of the frame immediately above the return address slot.
+  //
+  // Set up a stack frame and registers as follows:
+  //         fp[8]: CallerPC (lr)
+  //   fp -> fp[0]: CallerFP (old fp)
+  //         fp[-8]: SPOffset (new csp)
+  //         fp[-16]: CodeObject()
+  //         csp[...]: Saved doubles, if saved_doubles is true.
+  //         csp[8]: Memory reserved for the caller if extra_space != 0.
+  //                 Alignment padding, if necessary.
+  //  csp -> csp[0]: Space reserved for the return address.
+  //
+  // This function also stores the new frame information in the top frame, so
+  // that the new frame becomes the current frame.
+  void EnterExitFrame(bool save_doubles,
+                      const Register& scratch,
+                      int extra_space = 0);
+
+  // Leave the current exit frame, after a C function has returned to generated
+  // (JavaScript) code.
+  //
+  // This effectively unwinds the operation of EnterExitFrame:
+  //  * Preserved doubles are restored (if restore_doubles is true).
+  //  * The frame information is removed from the top frame.
+  //  * The exit frame is dropped.
+  //  * The stack pointer is reset to jssp.
+  //
+  // The stack pointer must be csp on entry.
+  void LeaveExitFrame(bool restore_doubles, const Register& scratch);
+
+  void LoadContext(Register dst, int context_chain_length);
+
+  // ---------------------------------------------------------------------------
+  // StatsCounter support
+
+  void SetCounter(StatsCounter* counter, int value, Register scratch1,
+                  Register scratch2);
+  void IncrementCounter(StatsCounter* counter, int value, Register scratch1,
+                        Register scratch2);
+  void DecrementCounter(StatsCounter* counter, int value, Register scratch1,
+                        Register scratch2);
+
+  // ---------------------------------------------------------------------------
+  // Garbage collector support (GC).
+
+  enum RememberedSetFinalAction {
+    kReturnAtEnd,
+    kFallThroughAtEnd
+  };
+
+  // Record in the remembered set the fact that we have a pointer to new space
+  // at the address pointed to by the addr register. Only works if addr is not
+  // in new space.
+  void RememberedSetHelper(Register object,  // Used for debug code.
+                           Register addr,
+                           Register scratch,
+                           SaveFPRegsMode save_fp,
+                           RememberedSetFinalAction and_then);
+
+  // Push and pop the registers that can hold pointers, as defined by the
+  // RegList constant kSafepointSavedRegisters.
+  void PushSafepointRegisters();
+  void PopSafepointRegisters();
+
+  // Store value in register src in the safepoint stack slot for register dst.
+  void StoreToSafepointRegisterSlot(Register src, Register dst) {
+    Poke(src, SafepointRegisterStackIndex(dst.code()) * kPointerSize);
+  }
+
+  void CheckPageFlagSet(const Register& object,
+                        const Register& scratch,
+                        int mask,
+                        Label* if_any_set);
+
+  void CheckPageFlagClear(const Register& object,
+                          const Register& scratch,
+                          int mask,
+                          Label* if_all_clear);
+
+  void CheckMapDeprecated(Handle<Map> map,
+                          Register scratch,
+                          Label* if_deprecated);
+
+  // Check if object is in new space and jump accordingly.
+  // Register 'object' is preserved.
+  void JumpIfNotInNewSpace(Register object,
+                           Label* branch) {
+    InNewSpace(object, ne, branch);
+  }
+
+  void JumpIfInNewSpace(Register object,
+                        Label* branch) {
+    InNewSpace(object, eq, branch);
+  }
+
+  // Notify the garbage collector that we wrote a pointer into an object.
+  // |object| is the object being stored into, |value| is the object being
+  // stored.  value and scratch registers are clobbered by the operation.
+  // The offset is the offset from the start of the object, not the offset from
+  // the tagged HeapObject pointer.  For use with FieldOperand(reg, off).
+  void RecordWriteField(
+      Register object,
+      int offset,
+      Register value,
+      Register scratch,
+      LinkRegisterStatus lr_status,
+      SaveFPRegsMode save_fp,
+      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
+      SmiCheck smi_check = INLINE_SMI_CHECK,
+      PregenExpectation pregen_expectation = MAYBE_PREGENERATED);
+
+  // As above, but the offset has the tag presubtracted. For use with
+  // MemOperand(reg, off).
+  inline void RecordWriteContextSlot(
+      Register context,
+      int offset,
+      Register value,
+      Register scratch,
+      LinkRegisterStatus lr_status,
+      SaveFPRegsMode save_fp,
+      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
+      SmiCheck smi_check = INLINE_SMI_CHECK,
+      PregenExpectation pregen_expectation = MAYBE_PREGENERATED) {
+    RecordWriteField(context,
+                     offset + kHeapObjectTag,
+                     value,
+                     scratch,
+                     lr_status,
+                     save_fp,
+                     remembered_set_action,
+                     smi_check,
+                     pregen_expectation);
+  }
+
+  // For a given |object| notify the garbage collector that the slot |address|
+  // has been written.  |value| is the object being stored. The value and
+  // address registers are clobbered by the operation.
+  void RecordWrite(
+      Register object,
+      Register address,
+      Register value,
+      LinkRegisterStatus lr_status,
+      SaveFPRegsMode save_fp,
+      RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
+      SmiCheck smi_check = INLINE_SMI_CHECK,
+      PregenExpectation pregen_expecation = MAYBE_PREGENERATED);
+
+  // Checks the color of an object. If the object is already grey or black
+  // then we just fall through, since it is already live. If it is white and
+  // we can determine that it doesn't need to be scanned, then we just mark it
+  // black and fall through. For the rest we jump to the label so the
+  // incremental marker can fix its assumptions.
+  void EnsureNotWhite(Register object,
+                      Register scratch1,
+                      Register scratch2,
+                      Register scratch3,
+                      Register scratch4,
+                      Label* object_is_white_and_not_data);
+
+  // Detects conservatively whether an object is data-only, i.e. it does need to
+  // be scanned by the garbage collector.
+  void JumpIfDataObject(Register value,
+                        Register scratch,
+                        Label* not_data_object);
+
+  // Helper for finding the mark bits for an address.
+  // Note that the behaviour slightly differs from other architectures.
+  // On exit:
+  //  - addr_reg is unchanged.
+  //  - The bitmap register points at the word with the mark bits.
+  //  - The shift register contains the index of the first color bit for this
+  //    object in the bitmap.
+  inline void GetMarkBits(Register addr_reg,
+                          Register bitmap_reg,
+                          Register shift_reg);
+
+  // Check if an object has a given incremental marking color.
+  void HasColor(Register object,
+                Register scratch0,
+                Register scratch1,
+                Label* has_color,
+                int first_bit,
+                int second_bit);
+
+  void JumpIfBlack(Register object,
+                   Register scratch0,
+                   Register scratch1,
+                   Label* on_black);
+
+
+  // ---------------------------------------------------------------------------
+  // Debugging.
+
+  // Calls Abort(msg) if the condition cond is not satisfied.
+  // Use --debug_code to enable.
+  void Assert(Condition cond, const char* msg);
+  void AssertRegisterIsClear(Register reg, const char* msg);
+  void AssertRegisterIsRoot(Register reg, Heap::RootListIndex index);
+  void AssertFastElements(Register elements);
+
+  // Abort if the specified register contains the invalid color bit pattern.
+  // The pattern must be in bits [1:0] of 'reg' register.
+  //
+  // If emit_debug_code() is false, this emits no code.
+  void AssertHasValidColor(const Register& reg);
+
+  // Abort if 'object' register doesn't point to a string object.
+  //
+  // If emit_debug_code() is false, this emits no code.
+  void AssertIsString(const Register& object);
+
+  // Like Assert(), but always enabled.
+  void Check(Condition cond, const char* msg);
+  void CheckRegisterIsClear(Register reg, const char* msg);
+
+  // Print a message to stdout and abort execution.
+  void Abort(const char* msg);
+
+  // Conditionally load the cached Array transitioned map of type
+  // transitioned_kind from the native context if the map in register
+  // map_in_out is the cached Array map in the native context of
+  // expected_kind.
+  void LoadTransitionedArrayMapConditional(
+      ElementsKind expected_kind,
+      ElementsKind transitioned_kind,
+      Register map_in_out,
+      Register scratch,
+      Label* no_map_match);
+
+  // Load the initial map for new Arrays from a JSFunction.
+  void LoadInitialArrayMap(Register function_in,
+                           Register scratch,
+                           Register map_out,
+                           ArrayHasHoles holes);
+
+  void LoadArrayFunction(Register function);
+  void LoadGlobalFunction(int index, Register function);
+
+  // Load the initial map from the global function. The registers function and
+  // map can be the same, function is then overwritten.
+  void LoadGlobalFunctionInitialMap(Register function,
+                                    Register map,
+                                    Register scratch);
+
+  // --------------------------------------------------------------------------
+  // Set the registers used internally by the MacroAssembler as scratch
+  // registers. These registers are used to implement behaviours which are not
+  // directly supported by A64, and where an intermediate result is required.
+  //
+  // Both tmp0 and tmp1 may be set to any X register except for xzr, sp,
+  // and StackPointer(). Also, they must not be the same register (though they
+  // may both be NoReg).
+  //
+  // It is valid to set either or both of these registers to NoReg if you don't
+  // want the MacroAssembler to use any scratch registers. In a debug build, the
+  // Assembler will assert that any registers it uses are valid. Be aware that
+  // this check is not present in release builds. If this is a problem, use the
+  // Assembler directly.
+  void SetScratchRegisters(const Register& tmp0, const Register& tmp1) {
+    // V8 assumes the macro assembler uses ip0 and ip1 as temp registers.
+    ASSERT(tmp0.IsNone() || tmp0.Is(ip0));
+    ASSERT(tmp1.IsNone() || tmp1.Is(ip1));
+
+    ASSERT(!AreAliased(xzr, csp, tmp0, tmp1));
+    ASSERT(!AreAliased(StackPointer(), tmp0, tmp1));
+    tmp0_ = tmp0;
+    tmp1_ = tmp1;
+  }
+
+  const Register& Tmp0() const {
+    return tmp0_;
+  }
+
+  const Register& Tmp1() const {
+    return tmp1_;
+  }
+
+  const Register WTmp0() const {
+    return Register(tmp0_.code(), kWRegSize);
+  }
+
+  const Register WTmp1() const {
+    return Register(tmp1_.code(), kWRegSize);
+  }
+
+  void SetFPScratchRegister(const FPRegister& fptmp0) {
+    fptmp0_ = fptmp0;
+  }
+
+  const FPRegister& FPTmp0() const {
+    return fptmp0_;
+  }
+
+  const Register AppropriateTempFor(
+      const Register& target,
+      const CPURegister& forbidden = NoCPUReg) const {
+    Register candidate = forbidden.Is(Tmp0()) ? Tmp1() : Tmp0();
+    ASSERT(!candidate.Is(target));
+    return Register(candidate.code(), target.SizeInBits());
+  }
+
+  const FPRegister AppropriateTempFor(
+      const FPRegister& target,
+      const CPURegister& forbidden = NoCPUReg) const {
+    USE(forbidden);
+    FPRegister candidate = FPTmp0();
+    ASSERT(!candidate.Is(forbidden));
+    ASSERT(!candidate.Is(target));
+    return FPRegister(candidate.code(), target.SizeInBits());
+  }
+
+  // Like printf, but print at run-time from generated code.
+  //
+  // The caller must ensure that arguments for floating-point placeholders
+  // (such as %e, %f or %g) are FPRegisters, and that arguments for integer
+  // placeholders are Registers.
+  //
+  // A maximum of four arguments may be given to any single Printf call. The
+  // arguments must be of the same type, but they do not need to have the same
+  // size.
+  //
+  // The following registers cannot be printed:
+  //    Tmp0(), Tmp1(), StackPointer(), csp.
+  //
+  // This function automatically preserves caller-saved registers so that
+  // calling code can use Printf at any point without having to worry about
+  // corruption. The preservation mechanism generates a lot of code. If this is
+  // a problem, preserve the important registers manually and then call
+  // PrintfNoPreserve. Callee-saved registers are not used by Printf, and are
+  // implicitly preserved.
+  //
+  // Unlike many MacroAssembler functions, x8 and x9 are guaranteed to be
+  // preserved, and can be printed. This allows Printf to be used during debug
+  // code.
+  //
+  // This function assumes (and asserts) that the current stack pointer is
+  // callee-saved, not caller-saved. This is most likely the case anyway, as a
+  // caller-saved stack pointer doesn't make a lot of sense.
+  void Printf(const char * format,
+              const CPURegister& arg0 = NoCPUReg,
+              const CPURegister& arg1 = NoCPUReg,
+              const CPURegister& arg2 = NoCPUReg,
+              const CPURegister& arg3 = NoCPUReg);
+
+  // Like Printf, but don't preserve any caller-saved registers, not even 'lr'.
+  //
+  // The return code from the system printf call will be returned in x0.
+  void PrintfNoPreserve(const char * format,
+                        const CPURegister& arg0 = NoCPUReg,
+                        const CPURegister& arg1 = NoCPUReg,
+                        const CPURegister& arg2 = NoCPUReg,
+                        const CPURegister& arg3 = NoCPUReg);
+
+  // Code ageing support functions.
+
+  // Code ageing on A64 works similarly to on ARM. When V8 wants to mark a
+  // function as old, it replaces some of the function prologue (generated by
+  // FullCodeGenerator::Generate) with a call to a special stub (ultimately
+  // generated by GenerateMakeCodeYoungAgainCommon). The stub restores the
+  // function prologue to its initial young state (indicating that it has been
+  // recently run) and continues. A young function is therefore one which has a
+  // normal frame setup sequence, and an old function has a code age sequence
+  // which calls a code ageing stub.
+
+  // Set up a basic stack frame for young code (or code exempt from ageing) with
+  // type FUNCTION. It may be patched later for code ageing support. This is
+  // done by to Code::PatchPlatformCodeAge and EmitCodeAgeSequence.
+  //
+  // This function takes an Assembler so it can be called from either a
+  // MacroAssembler or a PatchingAssembler context.
+  static void EmitFrameSetupForCodeAgePatching(Assembler * assm);
+
+  // Call EmitFrameSetupForCodeAgePatching from a MacroAssembler context.
+  void EmitFrameSetupForCodeAgePatching();
+
+  // Emit a code age sequence that calls the relevant code age stub. The code
+  // generated by this sequence is expected to replace the code generated by
+  // EmitFrameSetupForCodeAgePatching, and represents an old function.
+  //
+  // It never makes sense to call this other than in a patching context, so this
+  // method only accepts a PatchingAssembler.
+  //
+  // If stub is NULL, this function generates the code age sequence but omits
+  // the stub address that is normally embedded in the instruction stream. This
+  // can be used by debug code to verify code age sequences.
+  static void EmitCodeAgeSequence(PatchingAssembler * assm, Code * stub);
+
+  // Return true if the sequence is a young sequence geneated by
+  // EmitFrameSetupForCodeAgePatching. Otherwise, this method asserts that the
+  // sequence is a code age sequence (emitted by EmitCodeAgeSequence).
+  static bool IsYoungSequence(byte* sequence);
+
+#ifdef DEBUG
+  // Return true if the sequence is a code age sequence generated by
+  // EmitCodeAgeSequence.
+  static bool IsCodeAgeSequence(byte* sequence);
+#endif
+
+ private:
+  // Helpers for CopyFields.
+  // These each implement CopyFields in a different way.
+  void CopyFieldsLoopPairsHelper(Register dst, Register src, unsigned count,
+                                 Register scratch1, Register scratch2,
+                                 Register scratch3);
+  void CopyFieldsUnrolledPairsHelper(Register dst, Register src, unsigned count,
+                                     Register scratch1, Register scratch2);
+  void CopyFieldsUnrolledHelper(Register dst, Register src, unsigned count,
+                                Register scratch1);
+
+  // The actual Push and Pop implementations. These don't generate any code
+  // other than that required for the push or pop. This allows
+  // (Push|Pop)CPURegList to bundle together run-time assertions for a large
+  // block of registers.
+  //
+  // Note that size is per register, and is specified in bytes.
+  void PushHelper(int count, int size,
+                  const CPURegister& src0, const CPURegister& src1,
+                  const CPURegister& src2, const CPURegister& src3);
+  void PopHelper(int count, int size,
+                 const CPURegister& dst0, const CPURegister& dst1,
+                 const CPURegister& dst2, const CPURegister& dst3);
+
+  // Perform necessary maintenance operations before a push or pop.
+  //
+  // Note that size is per register, and is specified in bytes.
+  void PrepareForPush(int count, int size);
+  void PrepareForPop(int count, int size);
+
+  // Call Printf. On a native build, a simple call will be generated, but if the
+  // simulator is being used then a suitable pseudo-instruction is used. The
+  // arguments and stack (csp) must be prepared by the caller as for a normal
+  // AAPCS64 call to 'printf'.
+  //
+  // The 'type' argument specifies the type of the optional arguments.
+  void CallPrintf(CPURegister::RegisterType type = CPURegister::kNoRegister);
+
+  // Helper for throwing exceptions.  Compute a handler address and jump to
+  // it.  See the implementation for register usage.
+  void JumpToHandlerEntry(Register exception,
+                          Register object,
+                          Register state,
+                          Register scratch1,
+                          Register scratch2);
+
+  // Helper for implementing JumpIfNotInNewSpace and JumpIfInNewSpace.
+  void InNewSpace(Register object,
+                  Condition cond,  // eq for new space, ne otherwise.
+                  Label* branch);
+
+  // Try to convert a double to an int so that integer fast-paths may be
+  // used. Not every valid integer value is guaranteed to be caught.
+  // It supports both 32-bit and 64-bit integers depending whether 'as_int'
+  // is a W or X register.
+  //
+  // This does not distinguish between +0 and -0, so if this distinction is
+  // important it must be checked separately.
+  void TryConvertDoubleToInt(Register as_int,
+                             FPRegister value,
+                             FPRegister scratch_d,
+                             Label* on_successful_conversion,
+                             Label* on_failed_conversion = NULL);
+
+  bool generating_stub_;
+  bool allow_stub_calls_;
+#if DEBUG
+  // Tell whether any of the macro instruction can be used. When false the
+  // MacroAssembler will assert if a method which can emit a variable number
+  // of instructions is called.
+  bool allow_macro_instructions_;
+#endif
+  bool has_frame_;
+
+  // The Abort method should call a V8 runtime function, but the CallRuntime
+  // mechanism depends on CEntryStub. If use_real_aborts is false, Abort will
+  // use a simpler abort mechanism that doesn't depend on CEntryStub.
+  //
+  // The purpose of this is to allow Aborts to be compiled whilst CEntryStub is
+  // being generated.
+  bool use_real_aborts_;
+
+  // This handle will be patched with the code object on installation.
+  Handle<Object> code_object_;
+
+  // The register to use as a stack pointer for stack operations.
+  Register sp_;
+
+  // Scratch registers used internally by the MacroAssembler.
+  Register tmp0_;
+  Register tmp1_;
+  FPRegister fptmp0_;
+
+  void InitializeNewString(Register string,
+                           Register length,
+                           Heap::RootListIndex map_index,
+                           Register scratch1,
+                           Register scratch2);
+};
+
+
+// Use this scope when you need a one-to-one mapping bewteen methods and
+// instructions. This scope prevents the MacroAssembler from being called and
+// literal pools from being emitted. It also asserts the number of instructions
+// emitted is what you specified when creating the scope.
+class InstructionAccurateScope BASE_EMBEDDED {
+ public:
+  explicit InstructionAccurateScope(MacroAssembler* masm)
+      : masm_(masm), size_(0) {
+    masm_->StartBlockConstPool();
+#ifdef DEBUG
+    previous_allow_macro_instructions_ = masm_->allow_macro_instructions();
+    masm_->set_allow_macro_instructions(false);
+#endif
+  }
+
+  InstructionAccurateScope(MacroAssembler* masm, size_t count)
+      : masm_(masm), size_(count * kInstructionSize) {
+    masm_->StartBlockConstPool();
+#ifdef DEBUG
+    masm_->bind(&start_);
+    previous_allow_macro_instructions_ = masm_->allow_macro_instructions();
+    masm_->set_allow_macro_instructions(false);
+#endif
+  }
+
+  ~InstructionAccurateScope() {
+    masm_->EndBlockConstPool();
+#ifdef DEBUG
+    if (start_.is_bound()) {
+      ASSERT(masm_->SizeOfCodeGeneratedSince(&start_) == size_);
+    }
+    masm_->set_allow_macro_instructions(previous_allow_macro_instructions_);
+#endif
+  }
+
+ private:
+  MacroAssembler* masm_;
+  size_t size_;
+#ifdef DEBUG
+  Label start_;
+  bool previous_allow_macro_instructions_;
+#endif
+};
+
+
+inline MemOperand ContextMemOperand(Register context, int index) {
+  return MemOperand(context, Context::SlotOffset(index));
+}
+
+inline MemOperand GlobalObjectMemOperand() {
+  return ContextMemOperand(cp, Context::GLOBAL_OBJECT_INDEX);
+}
+
+
+// Encode and decode information about patchable inline SMI checks.
+class InlineSmiCheckInfo {
+ public:
+  explicit InlineSmiCheckInfo(Address info);
+
+  inline bool HasSmiCheck() const {
+    return smi_check_ != NULL;
+  }
+
+  inline const Register& SmiRegister() const {
+    return reg_;
+  }
+
+  inline Instruction* SmiCheck() const {
+    return smi_check_;
+  }
+
+  // Use MacroAssembler::InlineData to emit information about patchable inline
+  // SMI checks. The caller may specify 'reg' as NoReg and an unbound 'site' to
+  // indicate that there is no inline SMI check. Note that 'reg' cannot be csp.
+  //
+  // The generated patch information can be read using the InlineSMICheckInfo
+  // class.
+  static void Emit(MacroAssembler* masm, const Register& reg,
+                   const Label* smi_check);
+
+  // Emit information to indicate that there is no inline SMI check.
+  static void EmitNotInlined(MacroAssembler* masm) {
+    Label unbound;
+    Emit(masm, NoReg, &unbound);
+  }
+
+ private:
+  Register reg_;
+  Instruction* smi_check_;
+
+  // Fields in the data encoded by InlineData.
+
+  // A width of 5 (Rd_width) for the SMI register preclues the use of csp,
+  // since kSPRegInternalCode is 63. However, csp should never hold a SMI or be
+  // used in a patchable check. The Emit() method checks this.
+  //
+  // Note that the total size of the fields is restricted by the underlying
+  // storage size handled by the BitField class, which is a uint32_t.
+  class RegisterBits : public BitField<unsigned, 0, 5> {};
+  class DeltaBits : public BitField<uint32_t, 5, 32-5> {};
+};
+
+} }  // namespace v8::internal
+
+#ifdef GENERATED_CODE_COVERAGE
+#error "Unsupported option"
+#define CODE_COVERAGE_STRINGIFY(x) #x
+#define CODE_COVERAGE_TOSTRING(x) CODE_COVERAGE_STRINGIFY(x)
+#define __FILE_LINE__ __FILE__ ":" CODE_COVERAGE_TOSTRING(__LINE__)
+#define ACCESS_MASM(masm) masm->stop(__FILE_LINE__); masm->
+#else
+#define ACCESS_MASM(masm) masm->
+#endif
+
+#endif  // V8_A64_MACRO_ASSEMBLER_A64_H_