Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

17 files changed, 8070 insertions, 0 deletions

diff --git a/qemu/disas/libvixl/LICENCE b/qemu/disas/libvixl/LICENCE
new file mode 100644
index 000000000..b7e160a3f
--- /dev/null
+++ b/qemu/disas/libvixl/LICENCE
@@ -0,0 +1,30 @@
+LICENCE
+=======
+
+The software in this repository is covered by the following licence.
+
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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.
diff --git a/qemu/disas/libvixl/Makefile.objs b/qemu/disas/libvixl/Makefile.objs
new file mode 100644
index 000000000..17e6565d1
--- /dev/null
+++ b/qemu/disas/libvixl/Makefile.objs
@@ -0,0 +1,8 @@
+libvixl_OBJS = utils.o \
+               a64/instructions-a64.o \
+               a64/decoder-a64.o \
+               a64/disasm-a64.o
+
+$(addprefix $(obj)/,$(libvixl_OBJS)): QEMU_CFLAGS := -I$(SRC_PATH)/disas/libvixl $(QEMU_CFLAGS)
+
+common-obj-$(CONFIG_ARM_A64_DIS) += $(libvixl_OBJS)
diff --git a/qemu/disas/libvixl/README b/qemu/disas/libvixl/README
new file mode 100644
index 000000000..58db41c67
--- /dev/null
+++ b/qemu/disas/libvixl/README
@@ -0,0 +1,12 @@
+
+The code in this directory is a subset of libvixl:
+ https://github.com/armvixl/vixl
+(specifically, it is the set of files needed for disassembly only,
+taken from libvixl 1.7).
+Bugfixes should preferably be sent upstream initially.
+
+The disassembler does not currently support the entire A64 instruction
+set. Notably:
+ * No Advanced SIMD support.
+ * Limited support for system instructions.
+ * A few miscellaneous integer and floating point instructions are missing.
diff --git a/qemu/disas/libvixl/a64/assembler-a64.h b/qemu/disas/libvixl/a64/assembler-a64.h
new file mode 100644
index 000000000..35aaf20f7
--- /dev/null
+++ b/qemu/disas/libvixl/a64/assembler-a64.h
@@ -0,0 +1,2353 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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 VIXL_A64_ASSEMBLER_A64_H_
+#define VIXL_A64_ASSEMBLER_A64_H_
+
+#include <list>
+#include <stack>
+
+#include "globals.h"
+#include "utils.h"
+#include "code-buffer.h"
+#include "a64/instructions-a64.h"
+
+namespace vixl {
+
+typedef uint64_t RegList;
+static const int kRegListSizeInBits = sizeof(RegList) * 8;
+
+
+// Registers.
+
+// Some CPURegister methods can return Register and FPRegister types, so we
+// need to declare them in advance.
+class Register;
+class FPRegister;
+
+
+class CPURegister {
+ public:
+  enum RegisterType {
+    // The kInvalid value is used to detect uninitialized static instances,
+    // which are always zero-initialized before any constructors are called.
+    kInvalid = 0,
+    kRegister,
+    kFPRegister,
+    kNoRegister
+  };
+
+  CPURegister() : code_(0), size_(0), type_(kNoRegister) {
+    VIXL_ASSERT(!IsValid());
+    VIXL_ASSERT(IsNone());
+  }
+
+  CPURegister(unsigned code, unsigned size, RegisterType type)
+      : code_(code), size_(size), type_(type) {
+    VIXL_ASSERT(IsValidOrNone());
+  }
+
+  unsigned code() const {
+    VIXL_ASSERT(IsValid());
+    return code_;
+  }
+
+  RegisterType type() const {
+    VIXL_ASSERT(IsValidOrNone());
+    return type_;
+  }
+
+  RegList Bit() const {
+    VIXL_ASSERT(code_ < (sizeof(RegList) * 8));
+    return IsValid() ? (static_cast<RegList>(1) << code_) : 0;
+  }
+
+  unsigned size() const {
+    VIXL_ASSERT(IsValid());
+    return size_;
+  }
+
+  int SizeInBytes() const {
+    VIXL_ASSERT(IsValid());
+    VIXL_ASSERT(size() % 8 == 0);
+    return size_ / 8;
+  }
+
+  int SizeInBits() const {
+    VIXL_ASSERT(IsValid());
+    return size_;
+  }
+
+  bool Is32Bits() const {
+    VIXL_ASSERT(IsValid());
+    return size_ == 32;
+  }
+
+  bool Is64Bits() const {
+    VIXL_ASSERT(IsValid());
+    return size_ == 64;
+  }
+
+  bool IsValid() const {
+    if (IsValidRegister() || IsValidFPRegister()) {
+      VIXL_ASSERT(!IsNone());
+      return true;
+    } else {
+      VIXL_ASSERT(IsNone());
+      return false;
+    }
+  }
+
+  bool IsValidRegister() const {
+    return IsRegister() &&
+           ((size_ == kWRegSize) || (size_ == kXRegSize)) &&
+           ((code_ < kNumberOfRegisters) || (code_ == kSPRegInternalCode));
+  }
+
+  bool IsValidFPRegister() const {
+    return IsFPRegister() &&
+           ((size_ == kSRegSize) || (size_ == kDRegSize)) &&
+           (code_ < kNumberOfFPRegisters);
+  }
+
+  bool IsNone() const {
+    // kNoRegister types should always have size 0 and code 0.
+    VIXL_ASSERT((type_ != kNoRegister) || (code_ == 0));
+    VIXL_ASSERT((type_ != kNoRegister) || (size_ == 0));
+
+    return type_ == kNoRegister;
+  }
+
+  bool Aliases(const CPURegister& other) const {
+    VIXL_ASSERT(IsValidOrNone() && other.IsValidOrNone());
+    return (code_ == other.code_) && (type_ == other.type_);
+  }
+
+  bool Is(const CPURegister& other) const {
+    VIXL_ASSERT(IsValidOrNone() && other.IsValidOrNone());
+    return Aliases(other) && (size_ == other.size_);
+  }
+
+  bool IsZero() const {
+    VIXL_ASSERT(IsValid());
+    return IsRegister() && (code_ == kZeroRegCode);
+  }
+
+  bool IsSP() const {
+    VIXL_ASSERT(IsValid());
+    return IsRegister() && (code_ == kSPRegInternalCode);
+  }
+
+  bool IsRegister() const {
+    return type_ == kRegister;
+  }
+
+  bool IsFPRegister() const {
+    return type_ == kFPRegister;
+  }
+
+  bool IsW() const { return IsValidRegister() && Is32Bits(); }
+  bool IsX() const { return IsValidRegister() && Is64Bits(); }
+  bool IsS() const { return IsValidFPRegister() && Is32Bits(); }
+  bool IsD() const { return IsValidFPRegister() && Is64Bits(); }
+
+  const Register& W() const;
+  const Register& X() const;
+  const FPRegister& S() const;
+  const FPRegister& D() const;
+
+  bool IsSameSizeAndType(const CPURegister& other) const {
+    return (size_ == other.size_) && (type_ == other.type_);
+  }
+
+ protected:
+  unsigned code_;
+  unsigned size_;
+  RegisterType type_;
+
+ private:
+  bool IsValidOrNone() const {
+    return IsValid() || IsNone();
+  }
+};
+
+
+class Register : public CPURegister {
+ public:
+  Register() : CPURegister() {}
+  explicit Register(const CPURegister& other)
+      : CPURegister(other.code(), other.size(), other.type()) {
+    VIXL_ASSERT(IsValidRegister());
+  }
+  Register(unsigned code, unsigned size)
+      : CPURegister(code, size, kRegister) {}
+
+  bool IsValid() const {
+    VIXL_ASSERT(IsRegister() || IsNone());
+    return IsValidRegister();
+  }
+
+  static const Register& WRegFromCode(unsigned code);
+  static const Register& XRegFromCode(unsigned code);
+
+ private:
+  static const Register wregisters[];
+  static const Register xregisters[];
+};
+
+
+class FPRegister : public CPURegister {
+ public:
+  FPRegister() : CPURegister() {}
+  explicit FPRegister(const CPURegister& other)
+      : CPURegister(other.code(), other.size(), other.type()) {
+    VIXL_ASSERT(IsValidFPRegister());
+  }
+  FPRegister(unsigned code, unsigned size)
+      : CPURegister(code, size, kFPRegister) {}
+
+  bool IsValid() const {
+    VIXL_ASSERT(IsFPRegister() || IsNone());
+    return IsValidFPRegister();
+  }
+
+  static const FPRegister& SRegFromCode(unsigned code);
+  static const FPRegister& DRegFromCode(unsigned code);
+
+ private:
+  static const FPRegister sregisters[];
+  static const FPRegister dregisters[];
+};
+
+
+// No*Reg is used to indicate an unused argument, or an error case. Note that
+// these all compare equal (using the Is() method). The Register and FPRegister
+// variants are provided for convenience.
+const Register NoReg;
+const FPRegister NoFPReg;
+const CPURegister NoCPUReg;
+
+
+#define DEFINE_REGISTERS(N)  \
+const Register w##N(N, kWRegSize);  \
+const Register x##N(N, kXRegSize);
+REGISTER_CODE_LIST(DEFINE_REGISTERS)
+#undef DEFINE_REGISTERS
+const Register wsp(kSPRegInternalCode, kWRegSize);
+const Register sp(kSPRegInternalCode, kXRegSize);
+
+
+#define DEFINE_FPREGISTERS(N)  \
+const FPRegister s##N(N, kSRegSize);  \
+const FPRegister d##N(N, kDRegSize);
+REGISTER_CODE_LIST(DEFINE_FPREGISTERS)
+#undef DEFINE_FPREGISTERS
+
+
+// Registers aliases.
+const Register ip0 = x16;
+const Register ip1 = x17;
+const Register lr = x30;
+const Register xzr = x31;
+const Register wzr = w31;
+
+
+// AreAliased returns true if any of the named registers overlap. Arguments
+// set to NoReg are ignored. The system stack pointer may be specified.
+bool AreAliased(const CPURegister& reg1,
+                const CPURegister& reg2,
+                const CPURegister& reg3 = NoReg,
+                const CPURegister& reg4 = NoReg,
+                const CPURegister& reg5 = NoReg,
+                const CPURegister& reg6 = NoReg,
+                const CPURegister& reg7 = NoReg,
+                const CPURegister& reg8 = NoReg);
+
+
+// AreSameSizeAndType returns true if all of the specified registers have the
+// same size, and are of the same type. The system stack pointer may be
+// specified. Arguments set to NoReg are ignored, as are any subsequent
+// arguments. At least one argument (reg1) must be valid (not NoCPUReg).
+bool AreSameSizeAndType(const CPURegister& reg1,
+                        const CPURegister& reg2,
+                        const CPURegister& reg3 = NoCPUReg,
+                        const CPURegister& reg4 = NoCPUReg,
+                        const CPURegister& reg5 = NoCPUReg,
+                        const CPURegister& reg6 = NoCPUReg,
+                        const CPURegister& reg7 = NoCPUReg,
+                        const CPURegister& reg8 = NoCPUReg);
+
+
+// Lists of registers.
+class CPURegList {
+ public:
+  explicit CPURegList(CPURegister reg1,
+                      CPURegister reg2 = NoCPUReg,
+                      CPURegister reg3 = NoCPUReg,
+                      CPURegister reg4 = NoCPUReg)
+      : list_(reg1.Bit() | reg2.Bit() | reg3.Bit() | reg4.Bit()),
+        size_(reg1.size()), type_(reg1.type()) {
+    VIXL_ASSERT(AreSameSizeAndType(reg1, reg2, reg3, reg4));
+    VIXL_ASSERT(IsValid());
+  }
+
+  CPURegList(CPURegister::RegisterType type, unsigned size, RegList list)
+      : list_(list), size_(size), type_(type) {
+    VIXL_ASSERT(IsValid());
+  }
+
+  CPURegList(CPURegister::RegisterType type, unsigned size,
+             unsigned first_reg, unsigned last_reg)
+      : size_(size), type_(type) {
+    VIXL_ASSERT(((type == CPURegister::kRegister) &&
+                 (last_reg < kNumberOfRegisters)) ||
+                ((type == CPURegister::kFPRegister) &&
+                 (last_reg < kNumberOfFPRegisters)));
+    VIXL_ASSERT(last_reg >= first_reg);
+    list_ = (UINT64_C(1) << (last_reg + 1)) - 1;
+    list_ &= ~((UINT64_C(1) << first_reg) - 1);
+    VIXL_ASSERT(IsValid());
+  }
+
+  CPURegister::RegisterType type() const {
+    VIXL_ASSERT(IsValid());
+    return type_;
+  }
+
+  // Combine another CPURegList into this one. Registers that already exist in
+  // this list are left unchanged. The type and size of the registers in the
+  // 'other' list must match those in this list.
+  void Combine(const CPURegList& other) {
+    VIXL_ASSERT(IsValid());
+    VIXL_ASSERT(other.type() == type_);
+    VIXL_ASSERT(other.RegisterSizeInBits() == size_);
+    list_ |= other.list();
+  }
+
+  // Remove every register in the other CPURegList from this one. Registers that
+  // do not exist in this list are ignored. The type and size of the registers
+  // in the 'other' list must match those in this list.
+  void Remove(const CPURegList& other) {
+    VIXL_ASSERT(IsValid());
+    VIXL_ASSERT(other.type() == type_);
+    VIXL_ASSERT(other.RegisterSizeInBits() == size_);
+    list_ &= ~other.list();
+  }
+
+  // Variants of Combine and Remove which take a single register.
+  void Combine(const CPURegister& other) {
+    VIXL_ASSERT(other.type() == type_);
+    VIXL_ASSERT(other.size() == size_);
+    Combine(other.code());
+  }
+
+  void Remove(const CPURegister& other) {
+    VIXL_ASSERT(other.type() == type_);
+    VIXL_ASSERT(other.size() == size_);
+    Remove(other.code());
+  }
+
+  // Variants of Combine and Remove which take a single register by its code;
+  // the type and size of the register is inferred from this list.
+  void Combine(int code) {
+    VIXL_ASSERT(IsValid());
+    VIXL_ASSERT(CPURegister(code, size_, type_).IsValid());
+    list_ |= (UINT64_C(1) << code);
+  }
+
+  void Remove(int code) {
+    VIXL_ASSERT(IsValid());
+    VIXL_ASSERT(CPURegister(code, size_, type_).IsValid());
+    list_ &= ~(UINT64_C(1) << code);
+  }
+
+  static CPURegList Union(const CPURegList& list_1, const CPURegList& list_2) {
+    VIXL_ASSERT(list_1.type_ == list_2.type_);
+    VIXL_ASSERT(list_1.size_ == list_2.size_);
+    return CPURegList(list_1.type_, list_1.size_, list_1.list_ | list_2.list_);
+  }
+  static CPURegList Union(const CPURegList& list_1,
+                          const CPURegList& list_2,
+                          const CPURegList& list_3);
+  static CPURegList Union(const CPURegList& list_1,
+                          const CPURegList& list_2,
+                          const CPURegList& list_3,
+                          const CPURegList& list_4);
+
+  static CPURegList Intersection(const CPURegList& list_1,
+                                 const CPURegList& list_2) {
+    VIXL_ASSERT(list_1.type_ == list_2.type_);
+    VIXL_ASSERT(list_1.size_ == list_2.size_);
+    return CPURegList(list_1.type_, list_1.size_, list_1.list_ & list_2.list_);
+  }
+  static CPURegList Intersection(const CPURegList& list_1,
+                                 const CPURegList& list_2,
+                                 const CPURegList& list_3);
+  static CPURegList Intersection(const CPURegList& list_1,
+                                 const CPURegList& list_2,
+                                 const CPURegList& list_3,
+                                 const CPURegList& list_4);
+
+  RegList list() const {
+    VIXL_ASSERT(IsValid());
+    return list_;
+  }
+
+  void set_list(RegList new_list) {
+    VIXL_ASSERT(IsValid());
+    list_ = new_list;
+  }
+
+  // Remove all callee-saved registers from the list. This can be useful when
+  // preparing registers for an AAPCS64 function call, for example.
+  void RemoveCalleeSaved();
+
+  CPURegister PopLowestIndex();
+  CPURegister PopHighestIndex();
+
+  // AAPCS64 callee-saved registers.
+  static CPURegList GetCalleeSaved(unsigned size = kXRegSize);
+  static CPURegList GetCalleeSavedFP(unsigned size = kDRegSize);
+
+  // AAPCS64 caller-saved registers. Note that this includes lr.
+  static CPURegList GetCallerSaved(unsigned size = kXRegSize);
+  static CPURegList GetCallerSavedFP(unsigned size = kDRegSize);
+
+  bool IsEmpty() const {
+    VIXL_ASSERT(IsValid());
+    return list_ == 0;
+  }
+
+  bool IncludesAliasOf(const CPURegister& other) const {
+    VIXL_ASSERT(IsValid());
+    return (type_ == other.type()) && ((other.Bit() & list_) != 0);
+  }
+
+  bool IncludesAliasOf(int code) const {
+    VIXL_ASSERT(IsValid());
+    return ((code & list_) != 0);
+  }
+
+  int Count() const {
+    VIXL_ASSERT(IsValid());
+    return CountSetBits(list_, kRegListSizeInBits);
+  }
+
+  unsigned RegisterSizeInBits() const {
+    VIXL_ASSERT(IsValid());
+    return size_;
+  }
+
+  unsigned RegisterSizeInBytes() const {
+    int size_in_bits = RegisterSizeInBits();
+    VIXL_ASSERT((size_in_bits % 8) == 0);
+    return size_in_bits / 8;
+  }
+
+  unsigned TotalSizeInBytes() const {
+    VIXL_ASSERT(IsValid());
+    return RegisterSizeInBytes() * Count();
+  }
+
+ private:
+  RegList list_;
+  unsigned size_;
+  CPURegister::RegisterType type_;
+
+  bool IsValid() const;
+};
+
+
+// AAPCS64 callee-saved registers.
+extern const CPURegList kCalleeSaved;
+extern const CPURegList kCalleeSavedFP;
+
+
+// AAPCS64 caller-saved registers. Note that this includes lr.
+extern const CPURegList kCallerSaved;
+extern const CPURegList kCallerSavedFP;
+
+
+// Operand.
+class Operand {
+ public:
+  // #<immediate>
+  // where <immediate> is int64_t.
+  // This is allowed to be an implicit constructor because Operand is
+  // a wrapper class that doesn't normally perform any type conversion.
+  Operand(int64_t immediate);           // NOLINT(runtime/explicit)
+
+  // rm, {<shift> #<shift_amount>}
+  // where <shift> is one of {LSL, LSR, ASR, ROR}.
+  //       <shift_amount> is uint6_t.
+  // This is allowed to be an implicit constructor because Operand is
+  // a wrapper class that doesn't normally perform any type conversion.
+  Operand(Register reg,
+          Shift shift = LSL,
+          unsigned shift_amount = 0);   // NOLINT(runtime/explicit)
+
+  // rm, {<extend> {#<shift_amount>}}
+  // where <extend> is one of {UXTB, UXTH, UXTW, UXTX, SXTB, SXTH, SXTW, SXTX}.
+  //       <shift_amount> is uint2_t.
+  explicit Operand(Register reg, Extend extend, unsigned shift_amount = 0);
+
+  bool IsImmediate() const;
+  bool IsShiftedRegister() const;
+  bool IsExtendedRegister() const;
+  bool IsZero() const;
+
+  // This returns an LSL shift (<= 4) operand as an equivalent extend operand,
+  // which helps in the encoding of instructions that use the stack pointer.
+  Operand ToExtendedRegister() const;
+
+  int64_t immediate() const {
+    VIXL_ASSERT(IsImmediate());
+    return immediate_;
+  }
+
+  Register reg() const {
+    VIXL_ASSERT(IsShiftedRegister() || IsExtendedRegister());
+    return reg_;
+  }
+
+  Shift shift() const {
+    VIXL_ASSERT(IsShiftedRegister());
+    return shift_;
+  }
+
+  Extend extend() const {
+    VIXL_ASSERT(IsExtendedRegister());
+    return extend_;
+  }
+
+  unsigned shift_amount() const {
+    VIXL_ASSERT(IsShiftedRegister() || IsExtendedRegister());
+    return shift_amount_;
+  }
+
+ private:
+  int64_t immediate_;
+  Register reg_;
+  Shift shift_;
+  Extend extend_;
+  unsigned shift_amount_;
+};
+
+
+// MemOperand represents the addressing mode of a load or store instruction.
+class MemOperand {
+ public:
+  explicit MemOperand(Register base,
+                      int64_t offset = 0,
+                      AddrMode addrmode = Offset);
+  explicit MemOperand(Register base,
+                      Register regoffset,
+                      Shift shift = LSL,
+                      unsigned shift_amount = 0);
+  explicit MemOperand(Register base,
+                      Register regoffset,
+                      Extend extend,
+                      unsigned shift_amount = 0);
+  explicit MemOperand(Register base,
+                      const Operand& offset,
+                      AddrMode addrmode = Offset);
+
+  const Register& base() const { return base_; }
+  const Register& regoffset() const { return regoffset_; }
+  int64_t offset() const { return offset_; }
+  AddrMode addrmode() const { return addrmode_; }
+  Shift shift() const { return shift_; }
+  Extend extend() const { return extend_; }
+  unsigned shift_amount() const { return shift_amount_; }
+  bool IsImmediateOffset() const;
+  bool IsRegisterOffset() const;
+  bool IsPreIndex() const;
+  bool IsPostIndex() const;
+
+ private:
+  Register base_;
+  Register regoffset_;
+  int64_t offset_;
+  AddrMode addrmode_;
+  Shift shift_;
+  Extend extend_;
+  unsigned shift_amount_;
+};
+
+
+class Label {
+ public:
+  Label() : location_(kLocationUnbound) {}
+  ~Label() {
+    // If the label has been linked to, it needs to be bound to a target.
+    VIXL_ASSERT(!IsLinked() || IsBound());
+  }
+
+  bool IsBound() const { return location_ >= 0; }
+  bool IsLinked() const { return !links_.empty(); }
+
+  ptrdiff_t location() const { return location_; }
+
+ private:
+  // The list of linked instructions is stored in a stack-like structure. We
+  // don't use std::stack directly because it's slow for the common case where
+  // only one or two instructions refer to a label, and labels themselves are
+  // short-lived. This class behaves like std::stack, but the first few links
+  // are preallocated (configured by kPreallocatedLinks).
+  //
+  // If more than N links are required, this falls back to std::stack.
+  class LinksStack {
+   public:
+    LinksStack() : size_(0), links_extended_(NULL) {}
+    ~LinksStack() {
+      delete links_extended_;
+    }
+
+    size_t size() const {
+      return size_;
+    }
+
+    bool empty() const {
+      return size_ == 0;
+    }
+
+    void push(ptrdiff_t value) {
+      if (size_ < kPreallocatedLinks) {
+        links_[size_] = value;
+      } else {
+        if (links_extended_ == NULL) {
+          links_extended_ = new std::stack<ptrdiff_t>();
+        }
+        VIXL_ASSERT(size_ == (links_extended_->size() + kPreallocatedLinks));
+        links_extended_->push(value);
+      }
+      size_++;
+    }
+
+    ptrdiff_t top() const {
+      return (size_ <= kPreallocatedLinks) ? links_[size_ - 1]
+                                           : links_extended_->top();
+    }
+
+    void pop() {
+      size_--;
+      if (size_ >= kPreallocatedLinks) {
+        links_extended_->pop();
+        VIXL_ASSERT(size_ == (links_extended_->size() + kPreallocatedLinks));
+      }
+    }
+
+   private:
+    static const size_t kPreallocatedLinks = 4;
+
+    size_t size_;
+    ptrdiff_t links_[kPreallocatedLinks];
+    std::stack<ptrdiff_t> * links_extended_;
+  };
+
+  void Bind(ptrdiff_t location) {
+    // Labels can only be bound once.
+    VIXL_ASSERT(!IsBound());
+    location_ = location;
+  }
+
+  void AddLink(ptrdiff_t instruction) {
+    // If a label is bound, the assembler already has the information it needs
+    // to write the instruction, so there is no need to add it to links_.
+    VIXL_ASSERT(!IsBound());
+    links_.push(instruction);
+  }
+
+  ptrdiff_t GetAndRemoveNextLink() {
+    VIXL_ASSERT(IsLinked());
+    ptrdiff_t link = links_.top();
+    links_.pop();
+    return link;
+  }
+
+  // The offsets of the instructions that have linked to this label.
+  LinksStack links_;
+  // The label location.
+  ptrdiff_t location_;
+
+  static const ptrdiff_t kLocationUnbound = -1;
+
+  // It is not safe to copy labels, so disable the copy constructor by declaring
+  // it private (without an implementation).
+  Label(const Label&);
+
+  // The Assembler class is responsible for binding and linking labels, since
+  // the stored offsets need to be consistent with the Assembler's buffer.
+  friend class Assembler;
+};
+
+
+// A literal is a 32-bit or 64-bit piece of data stored in the instruction
+// stream and loaded through a pc relative load. The same literal can be
+// referred to by multiple instructions but a literal can only reside at one
+// place in memory. A literal can be used by a load before or after being
+// placed in memory.
+//
+// Internally an offset of 0 is associated with a literal which has been
+// neither used nor placed. Then two possibilities arise:
+//  1) the label is placed, the offset (stored as offset + 1) is used to
+//     resolve any subsequent load using the label.
+//  2) the label is not placed and offset is the offset of the last load using
+//     the literal (stored as -offset -1). If multiple loads refer to this
+//     literal then the last load holds the offset of the preceding load and
+//     all loads form a chain. Once the offset is placed all the loads in the
+//     chain are resolved and future loads fall back to possibility 1.
+class RawLiteral {
+ public:
+  RawLiteral() : size_(0), offset_(0), raw_value_(0) {}
+
+  size_t size() {
+    VIXL_STATIC_ASSERT(kDRegSizeInBytes == kXRegSizeInBytes);
+    VIXL_STATIC_ASSERT(kSRegSizeInBytes == kWRegSizeInBytes);
+    VIXL_ASSERT((size_ == kXRegSizeInBytes) || (size_ == kWRegSizeInBytes));
+    return size_;
+  }
+  uint64_t raw_value64() {
+    VIXL_ASSERT(size_ == kXRegSizeInBytes);
+    return raw_value_;
+  }
+  uint32_t raw_value32() {
+    VIXL_ASSERT(size_ == kWRegSizeInBytes);
+    VIXL_ASSERT(is_uint32(raw_value_) || is_int32(raw_value_));
+    return static_cast<uint32_t>(raw_value_);
+  }
+  bool IsUsed() { return offset_ < 0; }
+  bool IsPlaced() { return offset_ > 0; }
+
+ protected:
+  ptrdiff_t offset() {
+    VIXL_ASSERT(IsPlaced());
+    return offset_ - 1;
+  }
+  void set_offset(ptrdiff_t offset) {
+    VIXL_ASSERT(offset >= 0);
+    VIXL_ASSERT(IsWordAligned(offset));
+    VIXL_ASSERT(!IsPlaced());
+    offset_ = offset + 1;
+  }
+  ptrdiff_t last_use() {
+    VIXL_ASSERT(IsUsed());
+    return -offset_ - 1;
+  }
+  void set_last_use(ptrdiff_t offset) {
+    VIXL_ASSERT(offset >= 0);
+    VIXL_ASSERT(IsWordAligned(offset));
+    VIXL_ASSERT(!IsPlaced());
+    offset_ = -offset - 1;
+  }
+
+  size_t size_;
+  ptrdiff_t offset_;
+  uint64_t raw_value_;
+
+  friend class Assembler;
+};
+
+
+template <typename T>
+class Literal : public RawLiteral {
+ public:
+  explicit Literal(T value) {
+    size_ = sizeof(value);
+    memcpy(&raw_value_, &value, sizeof(value));
+  }
+};
+
+
+// Control whether or not position-independent code should be emitted.
+enum PositionIndependentCodeOption {
+  // All code generated will be position-independent; all branches and
+  // references to labels generated with the Label class will use PC-relative
+  // addressing.
+  PositionIndependentCode,
+
+  // Allow VIXL to generate code that refers to absolute addresses. With this
+  // option, it will not be possible to copy the code buffer and run it from a
+  // different address; code must be generated in its final location.
+  PositionDependentCode,
+
+  // Allow VIXL to assume that the bottom 12 bits of the address will be
+  // constant, but that the top 48 bits may change. This allows `adrp` to
+  // function in systems which copy code between pages, but otherwise maintain
+  // 4KB page alignment.
+  PageOffsetDependentCode
+};
+
+
+// Control how scaled- and unscaled-offset loads and stores are generated.
+enum LoadStoreScalingOption {
+  // Prefer scaled-immediate-offset instructions, but emit unscaled-offset,
+  // register-offset, pre-index or post-index instructions if necessary.
+  PreferScaledOffset,
+
+  // Prefer unscaled-immediate-offset instructions, but emit scaled-offset,
+  // register-offset, pre-index or post-index instructions if necessary.
+  PreferUnscaledOffset,
+
+  // Require scaled-immediate-offset instructions.
+  RequireScaledOffset,
+
+  // Require unscaled-immediate-offset instructions.
+  RequireUnscaledOffset
+};
+
+
+// Assembler.
+class Assembler {
+ public:
+  Assembler(size_t capacity,
+            PositionIndependentCodeOption pic = PositionIndependentCode);
+  Assembler(byte* buffer, size_t capacity,
+            PositionIndependentCodeOption pic = PositionIndependentCode);
+
+  // The destructor asserts that one of the following is true:
+  //  * The Assembler object has not been used.
+  //  * Nothing has been emitted since the last Reset() call.
+  //  * Nothing has been emitted since the last FinalizeCode() call.
+  ~Assembler();
+
+  // System functions.
+
+  // Start generating code from the beginning of the buffer, discarding any code
+  // and data that has already been emitted into the buffer.
+  void Reset();
+
+  // Finalize a code buffer of generated instructions. This function must be
+  // called before executing or copying code from the buffer.
+  void FinalizeCode();
+
+  // Label.
+  // Bind a label to the current PC.
+  void bind(Label* label);
+
+  // Bind a label to a specified offset from the start of the buffer.
+  void BindToOffset(Label* label, ptrdiff_t offset);
+
+  // Place a literal at the current PC.
+  void place(RawLiteral* literal);
+
+  ptrdiff_t CursorOffset() const {
+    return buffer_->CursorOffset();
+  }
+
+  ptrdiff_t BufferEndOffset() const {
+    return static_cast<ptrdiff_t>(buffer_->capacity());
+  }
+
+  // Return the address of an offset in the buffer.
+  template <typename T>
+  T GetOffsetAddress(ptrdiff_t offset) {
+    VIXL_STATIC_ASSERT(sizeof(T) >= sizeof(uintptr_t));
+    return buffer_->GetOffsetAddress<T>(offset);
+  }
+
+  // Return the address of a bound label.
+  template <typename T>
+  T GetLabelAddress(const Label * label) {
+    VIXL_ASSERT(label->IsBound());
+    VIXL_STATIC_ASSERT(sizeof(T) >= sizeof(uintptr_t));
+    return GetOffsetAddress<T>(label->location());
+  }
+
+  // Return the address of the cursor.
+  template <typename T>
+  T GetCursorAddress() {
+    VIXL_STATIC_ASSERT(sizeof(T) >= sizeof(uintptr_t));
+    return GetOffsetAddress<T>(CursorOffset());
+  }
+
+  // Return the address of the start of the buffer.
+  template <typename T>
+  T GetStartAddress() {
+    VIXL_STATIC_ASSERT(sizeof(T) >= sizeof(uintptr_t));
+    return GetOffsetAddress<T>(0);
+  }
+
+  // Instruction set functions.
+
+  // Branch / Jump instructions.
+  // Branch to register.
+  void br(const Register& xn);
+
+  // Branch with link to register.
+  void blr(const Register& xn);
+
+  // Branch to register with return hint.
+  void ret(const Register& xn = lr);
+
+  // Unconditional branch to label.
+  void b(Label* label);
+
+  // Conditional branch to label.
+  void b(Label* label, Condition cond);
+
+  // Unconditional branch to PC offset.
+  void b(int imm26);
+
+  // Conditional branch to PC offset.
+  void b(int imm19, Condition cond);
+
+  // Branch with link to label.
+  void bl(Label* label);
+
+  // Branch with link to PC offset.
+  void bl(int imm26);
+
+  // Compare and branch to label if zero.
+  void cbz(const Register& rt, Label* label);
+
+  // Compare and branch to PC offset if zero.
+  void cbz(const Register& rt, int imm19);
+
+  // Compare and branch to label if not zero.
+  void cbnz(const Register& rt, Label* label);
+
+  // Compare and branch to PC offset if not zero.
+  void cbnz(const Register& rt, int imm19);
+
+  // Test bit and branch to label if zero.
+  void tbz(const Register& rt, unsigned bit_pos, Label* label);
+
+  // Test bit and branch to PC offset if zero.
+  void tbz(const Register& rt, unsigned bit_pos, int imm14);
+
+  // Test bit and branch to label if not zero.
+  void tbnz(const Register& rt, unsigned bit_pos, Label* label);
+
+  // Test bit and branch to PC offset if not zero.
+  void tbnz(const Register& rt, unsigned bit_pos, int imm14);
+
+  // Address calculation instructions.
+  // Calculate a PC-relative address. Unlike for branches the offset in adr is
+  // unscaled (i.e. the result can be unaligned).
+
+  // Calculate the address of a label.
+  void adr(const Register& rd, Label* label);
+
+  // Calculate the address of a PC offset.
+  void adr(const Register& rd, int imm21);
+
+  // Calculate the page address of a label.
+  void adrp(const Register& rd, Label* label);
+
+  // Calculate the page address of a PC offset.
+  void adrp(const Register& rd, int imm21);
+
+  // Data Processing instructions.
+  // Add.
+  void add(const Register& rd,
+           const Register& rn,
+           const Operand& operand);
+
+  // Add and update status flags.
+  void adds(const Register& rd,
+            const Register& rn,
+            const Operand& operand);
+
+  // Compare negative.
+  void cmn(const Register& rn, const Operand& operand);
+
+  // Subtract.
+  void sub(const Register& rd,
+           const Register& rn,
+           const Operand& operand);
+
+  // Subtract and update status flags.
+  void subs(const Register& rd,
+            const Register& rn,
+            const Operand& operand);
+
+  // Compare.
+  void cmp(const Register& rn, const Operand& operand);
+
+  // Negate.
+  void neg(const Register& rd,
+           const Operand& operand);
+
+  // Negate and update status flags.
+  void negs(const Register& rd,
+            const Operand& operand);
+
+  // Add with carry bit.
+  void adc(const Register& rd,
+           const Register& rn,
+           const Operand& operand);
+
+  // Add with carry bit and update status flags.
+  void adcs(const Register& rd,
+            const Register& rn,
+            const Operand& operand);
+
+  // Subtract with carry bit.
+  void sbc(const Register& rd,
+           const Register& rn,
+           const Operand& operand);
+
+  // Subtract with carry bit and update status flags.
+  void sbcs(const Register& rd,
+            const Register& rn,
+            const Operand& operand);
+
+  // Negate with carry bit.
+  void ngc(const Register& rd,
+           const Operand& operand);
+
+  // Negate with carry bit and update status flags.
+  void ngcs(const Register& rd,
+            const Operand& operand);
+
+  // Logical instructions.
+  // Bitwise and (A & B).
+  void and_(const Register& rd,
+            const Register& rn,
+            const Operand& operand);
+
+  // Bitwise and (A & B) and update status flags.
+  void ands(const Register& rd,
+            const Register& rn,
+            const Operand& operand);
+
+  // Bit test and set flags.
+  void tst(const Register& rn, const Operand& operand);
+
+  // Bit clear (A & ~B).
+  void bic(const Register& rd,
+           const Register& rn,
+           const Operand& operand);
+
+  // Bit clear (A & ~B) and update status flags.
+  void bics(const Register& rd,
+            const Register& rn,
+            const Operand& operand);
+
+  // Bitwise or (A | B).
+  void orr(const Register& rd, const Register& rn, const Operand& operand);
+
+  // Bitwise nor (A | ~B).
+  void orn(const Register& rd, const Register& rn, const Operand& operand);
+
+  // Bitwise eor/xor (A ^ B).
+  void eor(const Register& rd, const Register& rn, const Operand& operand);
+
+  // Bitwise enor/xnor (A ^ ~B).
+  void eon(const Register& rd, const Register& rn, const Operand& operand);
+
+  // Logical shift left by variable.
+  void lslv(const Register& rd, const Register& rn, const Register& rm);
+
+  // Logical shift right by variable.
+  void lsrv(const Register& rd, const Register& rn, const Register& rm);
+
+  // Arithmetic shift right by variable.
+  void asrv(const Register& rd, const Register& rn, const Register& rm);
+
+  // Rotate right by variable.
+  void rorv(const Register& rd, const Register& rn, const Register& rm);
+
+  // Bitfield instructions.
+  // Bitfield move.
+  void bfm(const Register& rd,
+           const Register& rn,
+           unsigned immr,
+           unsigned imms);
+
+  // Signed bitfield move.
+  void sbfm(const Register& rd,
+            const Register& rn,
+            unsigned immr,
+            unsigned imms);
+
+  // Unsigned bitfield move.
+  void ubfm(const Register& rd,
+            const Register& rn,
+            unsigned immr,
+            unsigned imms);
+
+  // Bfm aliases.
+  // Bitfield insert.
+  void bfi(const Register& rd,
+           const Register& rn,
+           unsigned lsb,
+           unsigned width) {
+    VIXL_ASSERT(width >= 1);
+    VIXL_ASSERT(lsb + width <= rn.size());
+    bfm(rd, rn, (rd.size() - lsb) & (rd.size() - 1), width - 1);
+  }
+
+  // Bitfield extract and insert low.
+  void bfxil(const Register& rd,
+             const Register& rn,
+             unsigned lsb,
+             unsigned width) {
+    VIXL_ASSERT(width >= 1);
+    VIXL_ASSERT(lsb + width <= rn.size());
+    bfm(rd, rn, lsb, lsb + width - 1);
+  }
+
+  // Sbfm aliases.
+  // Arithmetic shift right.
+  void asr(const Register& rd, const Register& rn, unsigned shift) {
+    VIXL_ASSERT(shift < rd.size());
+    sbfm(rd, rn, shift, rd.size() - 1);
+  }
+
+  // Signed bitfield insert with zero at right.
+  void sbfiz(const Register& rd,
+             const Register& rn,
+             unsigned lsb,
+             unsigned width) {
+    VIXL_ASSERT(width >= 1);
+    VIXL_ASSERT(lsb + width <= rn.size());
+    sbfm(rd, rn, (rd.size() - lsb) & (rd.size() - 1), width - 1);
+  }
+
+  // Signed bitfield extract.
+  void sbfx(const Register& rd,
+            const Register& rn,
+            unsigned lsb,
+            unsigned width) {
+    VIXL_ASSERT(width >= 1);
+    VIXL_ASSERT(lsb + width <= rn.size());
+    sbfm(rd, rn, lsb, lsb + width - 1);
+  }
+
+  // Signed extend byte.
+  void sxtb(const Register& rd, const Register& rn) {
+    sbfm(rd, rn, 0, 7);
+  }
+
+  // Signed extend halfword.
+  void sxth(const Register& rd, const Register& rn) {
+    sbfm(rd, rn, 0, 15);
+  }
+
+  // Signed extend word.
+  void sxtw(const Register& rd, const Register& rn) {
+    sbfm(rd, rn, 0, 31);
+  }
+
+  // Ubfm aliases.
+  // Logical shift left.
+  void lsl(const Register& rd, const Register& rn, unsigned shift) {
+    unsigned reg_size = rd.size();
+    VIXL_ASSERT(shift < reg_size);
+    ubfm(rd, rn, (reg_size - shift) % reg_size, reg_size - shift - 1);
+  }
+
+  // Logical shift right.
+  void lsr(const Register& rd, const Register& rn, unsigned shift) {
+    VIXL_ASSERT(shift < rd.size());
+    ubfm(rd, rn, shift, rd.size() - 1);
+  }
+
+  // Unsigned bitfield insert with zero at right.
+  void ubfiz(const Register& rd,
+             const Register& rn,
+             unsigned lsb,
+             unsigned width) {
+    VIXL_ASSERT(width >= 1);
+    VIXL_ASSERT(lsb + width <= rn.size());
+    ubfm(rd, rn, (rd.size() - lsb) & (rd.size() - 1), width - 1);
+  }
+
+  // Unsigned bitfield extract.
+  void ubfx(const Register& rd,
+            const Register& rn,
+            unsigned lsb,
+            unsigned width) {
+    VIXL_ASSERT(width >= 1);
+    VIXL_ASSERT(lsb + width <= rn.size());
+    ubfm(rd, rn, lsb, lsb + width - 1);
+  }
+
+  // Unsigned extend byte.
+  void uxtb(const Register& rd, const Register& rn) {
+    ubfm(rd, rn, 0, 7);
+  }
+
+  // Unsigned extend halfword.
+  void uxth(const Register& rd, const Register& rn) {
+    ubfm(rd, rn, 0, 15);
+  }
+
+  // Unsigned extend word.
+  void uxtw(const Register& rd, const Register& rn) {
+    ubfm(rd, rn, 0, 31);
+  }
+
+  // Extract.
+  void extr(const Register& rd,
+            const Register& rn,
+            const Register& rm,
+            unsigned lsb);
+
+  // Conditional select: rd = cond ? rn : rm.
+  void csel(const Register& rd,
+            const Register& rn,
+            const Register& rm,
+            Condition cond);
+
+  // Conditional select increment: rd = cond ? rn : rm + 1.
+  void csinc(const Register& rd,
+             const Register& rn,
+             const Register& rm,
+             Condition cond);
+
+  // Conditional select inversion: rd = cond ? rn : ~rm.
+  void csinv(const Register& rd,
+             const Register& rn,
+             const Register& rm,
+             Condition cond);
+
+  // Conditional select negation: rd = cond ? rn : -rm.
+  void csneg(const Register& rd,
+             const Register& rn,
+             const Register& rm,
+             Condition cond);
+
+  // Conditional set: rd = cond ? 1 : 0.
+  void cset(const Register& rd, Condition cond);
+
+  // Conditional set mask: rd = cond ? -1 : 0.
+  void csetm(const Register& rd, Condition cond);
+
+  // Conditional increment: rd = cond ? rn + 1 : rn.
+  void cinc(const Register& rd, const Register& rn, Condition cond);
+
+  // Conditional invert: rd = cond ? ~rn : rn.
+  void cinv(const Register& rd, const Register& rn, Condition cond);
+
+  // Conditional negate: rd = cond ? -rn : rn.
+  void cneg(const Register& rd, const Register& rn, Condition cond);
+
+  // Rotate right.
+  void ror(const Register& rd, const Register& rs, unsigned shift) {
+    extr(rd, rs, rs, shift);
+  }
+
+  // Conditional comparison.
+  // Conditional compare negative.
+  void ccmn(const Register& rn,
+            const Operand& operand,
+            StatusFlags nzcv,
+            Condition cond);
+
+  // Conditional compare.
+  void ccmp(const Register& rn,
+            const Operand& operand,
+            StatusFlags nzcv,
+            Condition cond);
+
+  // Multiply.
+  void mul(const Register& rd, const Register& rn, const Register& rm);
+
+  // Negated multiply.
+  void mneg(const Register& rd, const Register& rn, const Register& rm);
+
+  // Signed long multiply: 32 x 32 -> 64-bit.
+  void smull(const Register& rd, const Register& rn, const Register& rm);
+
+  // Signed multiply high: 64 x 64 -> 64-bit <127:64>.
+  void smulh(const Register& xd, const Register& xn, const Register& xm);
+
+  // Multiply and accumulate.
+  void madd(const Register& rd,
+            const Register& rn,
+            const Register& rm,
+            const Register& ra);
+
+  // Multiply and subtract.
+  void msub(const Register& rd,
+            const Register& rn,
+            const Register& rm,
+            const Register& ra);
+
+  // Signed long multiply and accumulate: 32 x 32 + 64 -> 64-bit.
+  void smaddl(const Register& rd,
+              const Register& rn,
+              const Register& rm,
+              const Register& ra);
+
+  // Unsigned long multiply and accumulate: 32 x 32 + 64 -> 64-bit.
+  void umaddl(const Register& rd,
+              const Register& rn,
+              const Register& rm,
+              const Register& ra);
+
+  // Signed long multiply and subtract: 64 - (32 x 32) -> 64-bit.
+  void smsubl(const Register& rd,
+              const Register& rn,
+              const Register& rm,
+              const Register& ra);
+
+  // Unsigned long multiply and subtract: 64 - (32 x 32) -> 64-bit.
+  void umsubl(const Register& rd,
+              const Register& rn,
+              const Register& rm,
+              const Register& ra);
+
+  // Signed integer divide.
+  void sdiv(const Register& rd, const Register& rn, const Register& rm);
+
+  // Unsigned integer divide.
+  void udiv(const Register& rd, const Register& rn, const Register& rm);
+
+  // Bit reverse.
+  void rbit(const Register& rd, const Register& rn);
+
+  // Reverse bytes in 16-bit half words.
+  void rev16(const Register& rd, const Register& rn);
+
+  // Reverse bytes in 32-bit words.
+  void rev32(const Register& rd, const Register& rn);
+
+  // Reverse bytes.
+  void rev(const Register& rd, const Register& rn);
+
+  // Count leading zeroes.
+  void clz(const Register& rd, const Register& rn);
+
+  // Count leading sign bits.
+  void cls(const Register& rd, const Register& rn);
+
+  // Memory instructions.
+  // Load integer or FP register.
+  void ldr(const CPURegister& rt, const MemOperand& src,
+           LoadStoreScalingOption option = PreferScaledOffset);
+
+  // Store integer or FP register.
+  void str(const CPURegister& rt, const MemOperand& dst,
+           LoadStoreScalingOption option = PreferScaledOffset);
+
+  // Load word with sign extension.
+  void ldrsw(const Register& rt, const MemOperand& src,
+             LoadStoreScalingOption option = PreferScaledOffset);
+
+  // Load byte.
+  void ldrb(const Register& rt, const MemOperand& src,
+            LoadStoreScalingOption option = PreferScaledOffset);
+
+  // Store byte.
+  void strb(const Register& rt, const MemOperand& dst,
+            LoadStoreScalingOption option = PreferScaledOffset);
+
+  // Load byte with sign extension.
+  void ldrsb(const Register& rt, const MemOperand& src,
+             LoadStoreScalingOption option = PreferScaledOffset);
+
+  // Load half-word.
+  void ldrh(const Register& rt, const MemOperand& src,
+            LoadStoreScalingOption option = PreferScaledOffset);
+
+  // Store half-word.
+  void strh(const Register& rt, const MemOperand& dst,
+            LoadStoreScalingOption option = PreferScaledOffset);
+
+  // Load half-word with sign extension.
+  void ldrsh(const Register& rt, const MemOperand& src,
+             LoadStoreScalingOption option = PreferScaledOffset);
+
+  // Load integer or FP register (with unscaled offset).
+  void ldur(const CPURegister& rt, const MemOperand& src,
+            LoadStoreScalingOption option = PreferUnscaledOffset);
+
+  // Store integer or FP register (with unscaled offset).
+  void stur(const CPURegister& rt, const MemOperand& src,
+            LoadStoreScalingOption option = PreferUnscaledOffset);
+
+  // Load word with sign extension.
+  void ldursw(const Register& rt, const MemOperand& src,
+              LoadStoreScalingOption option = PreferUnscaledOffset);
+
+  // Load byte (with unscaled offset).
+  void ldurb(const Register& rt, const MemOperand& src,
+             LoadStoreScalingOption option = PreferUnscaledOffset);
+
+  // Store byte (with unscaled offset).
+  void sturb(const Register& rt, const MemOperand& dst,
+             LoadStoreScalingOption option = PreferUnscaledOffset);
+
+  // Load byte with sign extension (and unscaled offset).
+  void ldursb(const Register& rt, const MemOperand& src,
+              LoadStoreScalingOption option = PreferUnscaledOffset);
+
+  // Load half-word (with unscaled offset).
+  void ldurh(const Register& rt, const MemOperand& src,
+             LoadStoreScalingOption option = PreferUnscaledOffset);
+
+  // Store half-word (with unscaled offset).
+  void sturh(const Register& rt, const MemOperand& dst,
+             LoadStoreScalingOption option = PreferUnscaledOffset);
+
+  // Load half-word with sign extension (and unscaled offset).
+  void ldursh(const Register& rt, const MemOperand& src,
+              LoadStoreScalingOption option = PreferUnscaledOffset);
+
+  // Load integer or FP register pair.
+  void ldp(const CPURegister& rt, const CPURegister& rt2,
+           const MemOperand& src);
+
+  // Store integer or FP register pair.
+  void stp(const CPURegister& rt, const CPURegister& rt2,
+           const MemOperand& dst);
+
+  // Load word pair with sign extension.
+  void ldpsw(const Register& rt, const Register& rt2, const MemOperand& src);
+
+  // Load integer or FP register pair, non-temporal.
+  void ldnp(const CPURegister& rt, const CPURegister& rt2,
+            const MemOperand& src);
+
+  // Store integer or FP register pair, non-temporal.
+  void stnp(const CPURegister& rt, const CPURegister& rt2,
+            const MemOperand& dst);
+
+  // Load integer or FP register from literal pool.
+  void ldr(const CPURegister& rt, RawLiteral* literal);
+
+  // Load word with sign extension from literal pool.
+  void ldrsw(const Register& rt, RawLiteral* literal);
+
+  // Load integer or FP register from pc + imm19 << 2.
+  void ldr(const CPURegister& rt, int imm19);
+
+  // Load word with sign extension from pc + imm19 << 2.
+  void ldrsw(const Register& rt, int imm19);
+
+  // Store exclusive byte.
+  void stxrb(const Register& rs, const Register& rt, const MemOperand& dst);
+
+  // Store exclusive half-word.
+  void stxrh(const Register& rs, const Register& rt, const MemOperand& dst);
+
+  // Store exclusive register.
+  void stxr(const Register& rs, const Register& rt, const MemOperand& dst);
+
+  // Load exclusive byte.
+  void ldxrb(const Register& rt, const MemOperand& src);
+
+  // Load exclusive half-word.
+  void ldxrh(const Register& rt, const MemOperand& src);
+
+  // Load exclusive register.
+  void ldxr(const Register& rt, const MemOperand& src);
+
+  // Store exclusive register pair.
+  void stxp(const Register& rs,
+            const Register& rt,
+            const Register& rt2,
+            const MemOperand& dst);
+
+  // Load exclusive register pair.
+  void ldxp(const Register& rt, const Register& rt2, const MemOperand& src);
+
+  // Store-release exclusive byte.
+  void stlxrb(const Register& rs, const Register& rt, const MemOperand& dst);
+
+  // Store-release exclusive half-word.
+  void stlxrh(const Register& rs, const Register& rt, const MemOperand& dst);
+
+  // Store-release exclusive register.
+  void stlxr(const Register& rs, const Register& rt, const MemOperand& dst);
+
+  // Load-acquire exclusive byte.
+  void ldaxrb(const Register& rt, const MemOperand& src);
+
+  // Load-acquire exclusive half-word.
+  void ldaxrh(const Register& rt, const MemOperand& src);
+
+  // Load-acquire exclusive register.
+  void ldaxr(const Register& rt, const MemOperand& src);
+
+  // Store-release exclusive register pair.
+  void stlxp(const Register& rs,
+             const Register& rt,
+             const Register& rt2,
+             const MemOperand& dst);
+
+  // Load-acquire exclusive register pair.
+  void ldaxp(const Register& rt, const Register& rt2, const MemOperand& src);
+
+  // Store-release byte.
+  void stlrb(const Register& rt, const MemOperand& dst);
+
+  // Store-release half-word.
+  void stlrh(const Register& rt, const MemOperand& dst);
+
+  // Store-release register.
+  void stlr(const Register& rt, const MemOperand& dst);
+
+  // Load-acquire byte.
+  void ldarb(const Register& rt, const MemOperand& src);
+
+  // Load-acquire half-word.
+  void ldarh(const Register& rt, const MemOperand& src);
+
+  // Load-acquire register.
+  void ldar(const Register& rt, const MemOperand& src);
+
+  // Prefetch memory.
+  void prfm(PrefetchOperation op, const MemOperand& addr,
+            LoadStoreScalingOption option = PreferScaledOffset);
+
+  // Prefetch memory (with unscaled offset).
+  void prfum(PrefetchOperation op, const MemOperand& addr,
+             LoadStoreScalingOption option = PreferUnscaledOffset);
+
+  // Prefetch memory in the literal pool.
+  void prfm(PrefetchOperation op, RawLiteral* literal);
+
+  // Prefetch from pc + imm19 << 2.
+  void prfm(PrefetchOperation op, int imm19);
+
+  // Move instructions. The default shift of -1 indicates that the move
+  // instruction will calculate an appropriate 16-bit immediate and left shift
+  // that is equal to the 64-bit immediate argument. If an explicit left shift
+  // is specified (0, 16, 32 or 48), the immediate must be a 16-bit value.
+  //
+  // For movk, an explicit shift can be used to indicate which half word should
+  // be overwritten, eg. movk(x0, 0, 0) will overwrite the least-significant
+  // half word with zero, whereas movk(x0, 0, 48) will overwrite the
+  // most-significant.
+
+  // Move immediate and keep.
+  void movk(const Register& rd, uint64_t imm, int shift = -1) {
+    MoveWide(rd, imm, shift, MOVK);
+  }
+
+  // Move inverted immediate.
+  void movn(const Register& rd, uint64_t imm, int shift = -1) {
+    MoveWide(rd, imm, shift, MOVN);
+  }
+
+  // Move immediate.
+  void movz(const Register& rd, uint64_t imm, int shift = -1) {
+    MoveWide(rd, imm, shift, MOVZ);
+  }
+
+  // Misc instructions.
+  // Monitor debug-mode breakpoint.
+  void brk(int code);
+
+  // Halting debug-mode breakpoint.
+  void hlt(int code);
+
+  // Move register to register.
+  void mov(const Register& rd, const Register& rn);
+
+  // Move inverted operand to register.
+  void mvn(const Register& rd, const Operand& operand);
+
+  // System instructions.
+  // Move to register from system register.
+  void mrs(const Register& rt, SystemRegister sysreg);
+
+  // Move from register to system register.
+  void msr(SystemRegister sysreg, const Register& rt);
+
+  // System hint.
+  void hint(SystemHint code);
+
+  // Clear exclusive monitor.
+  void clrex(int imm4 = 0xf);
+
+  // Data memory barrier.
+  void dmb(BarrierDomain domain, BarrierType type);
+
+  // Data synchronization barrier.
+  void dsb(BarrierDomain domain, BarrierType type);
+
+  // Instruction synchronization barrier.
+  void isb();
+
+  // Alias for system instructions.
+  // No-op.
+  void nop() {
+    hint(NOP);
+  }
+
+  // FP instructions.
+  // Move double precision immediate to FP register.
+  void fmov(const FPRegister& fd, double imm);
+
+  // Move single precision immediate to FP register.
+  void fmov(const FPRegister& fd, float imm);
+
+  // Move FP register to register.
+  void fmov(const Register& rd, const FPRegister& fn);
+
+  // Move register to FP register.
+  void fmov(const FPRegister& fd, const Register& rn);
+
+  // Move FP register to FP register.
+  void fmov(const FPRegister& fd, const FPRegister& fn);
+
+  // FP add.
+  void fadd(const FPRegister& fd, const FPRegister& fn, const FPRegister& fm);
+
+  // FP subtract.
+  void fsub(const FPRegister& fd, const FPRegister& fn, const FPRegister& fm);
+
+  // FP multiply.
+  void fmul(const FPRegister& fd, const FPRegister& fn, const FPRegister& fm);
+
+  // FP fused multiply and add.
+  void fmadd(const FPRegister& fd,
+             const FPRegister& fn,
+             const FPRegister& fm,
+             const FPRegister& fa);
+
+  // FP fused multiply and subtract.
+  void fmsub(const FPRegister& fd,
+             const FPRegister& fn,
+             const FPRegister& fm,
+             const FPRegister& fa);
+
+  // FP fused multiply, add and negate.
+  void fnmadd(const FPRegister& fd,
+              const FPRegister& fn,
+              const FPRegister& fm,
+              const FPRegister& fa);
+
+  // FP fused multiply, subtract and negate.
+  void fnmsub(const FPRegister& fd,
+              const FPRegister& fn,
+              const FPRegister& fm,
+              const FPRegister& fa);
+
+  // FP divide.
+  void fdiv(const FPRegister& fd, const FPRegister& fn, const FPRegister& fm);
+
+  // FP maximum.
+  void fmax(const FPRegister& fd, const FPRegister& fn, const FPRegister& fm);
+
+  // FP minimum.
+  void fmin(const FPRegister& fd, const FPRegister& fn, const FPRegister& fm);
+
+  // FP maximum number.
+  void fmaxnm(const FPRegister& fd, const FPRegister& fn, const FPRegister& fm);
+
+  // FP minimum number.
+  void fminnm(const FPRegister& fd, const FPRegister& fn, const FPRegister& fm);
+
+  // FP absolute.
+  void fabs(const FPRegister& fd, const FPRegister& fn);
+
+  // FP negate.
+  void fneg(const FPRegister& fd, const FPRegister& fn);
+
+  // FP square root.
+  void fsqrt(const FPRegister& fd, const FPRegister& fn);
+
+  // FP round to integer (nearest with ties to away).
+  void frinta(const FPRegister& fd, const FPRegister& fn);
+
+  // FP round to integer (implicit rounding).
+  void frinti(const FPRegister& fd, const FPRegister& fn);
+
+  // FP round to integer (toward minus infinity).
+  void frintm(const FPRegister& fd, const FPRegister& fn);
+
+  // FP round to integer (nearest with ties to even).
+  void frintn(const FPRegister& fd, const FPRegister& fn);
+
+  // FP round to integer (toward plus infinity).
+  void frintp(const FPRegister& fd, const FPRegister& fn);
+
+  // FP round to integer (exact, implicit rounding).
+  void frintx(const FPRegister& fd, const FPRegister& fn);
+
+  // FP round to integer (towards zero).
+  void frintz(const FPRegister& fd, const FPRegister& fn);
+
+  // FP compare registers.
+  void fcmp(const FPRegister& fn, const FPRegister& fm);
+
+  // FP compare immediate.
+  void fcmp(const FPRegister& fn, double value);
+
+  // FP conditional compare.
+  void fccmp(const FPRegister& fn,
+             const FPRegister& fm,
+             StatusFlags nzcv,
+             Condition cond);
+
+  // FP conditional select.
+  void fcsel(const FPRegister& fd,
+             const FPRegister& fn,
+             const FPRegister& fm,
+             Condition cond);
+
+  // Common FP Convert function.
+  void FPConvertToInt(const Register& rd,
+                      const FPRegister& fn,
+                      FPIntegerConvertOp op);
+
+  // FP convert between single and double precision.
+  void fcvt(const FPRegister& fd, const FPRegister& fn);
+
+  // Convert FP to signed integer (nearest with ties to away).
+  void fcvtas(const Register& rd, const FPRegister& fn);
+
+  // Convert FP to unsigned integer (nearest with ties to away).
+  void fcvtau(const Register& rd, const FPRegister& fn);
+
+  // Convert FP to signed integer (round towards -infinity).
+  void fcvtms(const Register& rd, const FPRegister& fn);
+
+  // Convert FP to unsigned integer (round towards -infinity).
+  void fcvtmu(const Register& rd, const FPRegister& fn);
+
+  // Convert FP to signed integer (nearest with ties to even).
+  void fcvtns(const Register& rd, const FPRegister& fn);
+
+  // Convert FP to unsigned integer (nearest with ties to even).
+  void fcvtnu(const Register& rd, const FPRegister& fn);
+
+  // Convert FP to signed integer (round towards zero).
+  void fcvtzs(const Register& rd, const FPRegister& fn);
+
+  // Convert FP to unsigned integer (round towards zero).
+  void fcvtzu(const Register& rd, const FPRegister& fn);
+
+  // Convert signed integer or fixed point to FP.
+  void scvtf(const FPRegister& fd, const Register& rn, unsigned fbits = 0);
+
+  // Convert unsigned integer or fixed point to FP.
+  void ucvtf(const FPRegister& fd, const Register& rn, unsigned fbits = 0);
+
+  // Emit generic instructions.
+  // Emit raw instructions into the instruction stream.
+  void dci(Instr raw_inst) { Emit(raw_inst); }
+
+  // Emit 32 bits of data into the instruction stream.
+  void dc32(uint32_t data) {
+    VIXL_ASSERT(buffer_monitor_ > 0);
+    buffer_->Emit32(data);
+  }
+
+  // Emit 64 bits of data into the instruction stream.
+  void dc64(uint64_t data) {
+    VIXL_ASSERT(buffer_monitor_ > 0);
+    buffer_->Emit64(data);
+  }
+
+  // Copy a string into the instruction stream, including the terminating NULL
+  // character. The instruction pointer is then aligned correctly for
+  // subsequent instructions.
+  void EmitString(const char * string) {
+    VIXL_ASSERT(string != NULL);
+    VIXL_ASSERT(buffer_monitor_ > 0);
+
+    buffer_->EmitString(string);
+    buffer_->Align();
+  }
+
+  // Code generation helpers.
+
+  // Register encoding.
+  static Instr Rd(CPURegister rd) {
+    VIXL_ASSERT(rd.code() != kSPRegInternalCode);
+    return rd.code() << Rd_offset;
+  }
+
+  static Instr Rn(CPURegister rn) {
+    VIXL_ASSERT(rn.code() != kSPRegInternalCode);
+    return rn.code() << Rn_offset;
+  }
+
+  static Instr Rm(CPURegister rm) {
+    VIXL_ASSERT(rm.code() != kSPRegInternalCode);
+    return rm.code() << Rm_offset;
+  }
+
+  static Instr Ra(CPURegister ra) {
+    VIXL_ASSERT(ra.code() != kSPRegInternalCode);
+    return ra.code() << Ra_offset;
+  }
+
+  static Instr Rt(CPURegister rt) {
+    VIXL_ASSERT(rt.code() != kSPRegInternalCode);
+    return rt.code() << Rt_offset;
+  }
+
+  static Instr Rt2(CPURegister rt2) {
+    VIXL_ASSERT(rt2.code() != kSPRegInternalCode);
+    return rt2.code() << Rt2_offset;
+  }
+
+  static Instr Rs(CPURegister rs) {
+    VIXL_ASSERT(rs.code() != kSPRegInternalCode);
+    return rs.code() << Rs_offset;
+  }
+
+  // These encoding functions allow the stack pointer to be encoded, and
+  // disallow the zero register.
+  static Instr RdSP(Register rd) {
+    VIXL_ASSERT(!rd.IsZero());
+    return (rd.code() & kRegCodeMask) << Rd_offset;
+  }
+
+  static Instr RnSP(Register rn) {
+    VIXL_ASSERT(!rn.IsZero());
+    return (rn.code() & kRegCodeMask) << Rn_offset;
+  }
+
+  // Flags encoding.
+  static Instr Flags(FlagsUpdate S) {
+    if (S == SetFlags) {
+      return 1 << FlagsUpdate_offset;
+    } else if (S == LeaveFlags) {
+      return 0 << FlagsUpdate_offset;
+    }
+    VIXL_UNREACHABLE();
+    return 0;
+  }
+
+  static Instr Cond(Condition cond) {
+    return cond << Condition_offset;
+  }
+
+  // PC-relative address encoding.
+  static Instr ImmPCRelAddress(int imm21) {
+    VIXL_ASSERT(is_int21(imm21));
+    Instr imm = static_cast<Instr>(truncate_to_int21(imm21));
+    Instr immhi = (imm >> ImmPCRelLo_width) << ImmPCRelHi_offset;
+    Instr immlo = imm << ImmPCRelLo_offset;
+    return (immhi & ImmPCRelHi_mask) | (immlo & ImmPCRelLo_mask);
+  }
+
+  // Branch encoding.
+  static Instr ImmUncondBranch(int imm26) {
+    VIXL_ASSERT(is_int26(imm26));
+    return truncate_to_int26(imm26) << ImmUncondBranch_offset;
+  }
+
+  static Instr ImmCondBranch(int imm19) {
+    VIXL_ASSERT(is_int19(imm19));
+    return truncate_to_int19(imm19) << ImmCondBranch_offset;
+  }
+
+  static Instr ImmCmpBranch(int imm19) {
+    VIXL_ASSERT(is_int19(imm19));
+    return truncate_to_int19(imm19) << ImmCmpBranch_offset;
+  }
+
+  static Instr ImmTestBranch(int imm14) {
+    VIXL_ASSERT(is_int14(imm14));
+    return truncate_to_int14(imm14) << ImmTestBranch_offset;
+  }
+
+  static Instr ImmTestBranchBit(unsigned bit_pos) {
+    VIXL_ASSERT(is_uint6(bit_pos));
+    // Subtract five from the shift offset, as we need bit 5 from bit_pos.
+    unsigned b5 = bit_pos << (ImmTestBranchBit5_offset - 5);
+    unsigned b40 = bit_pos << ImmTestBranchBit40_offset;
+    b5 &= ImmTestBranchBit5_mask;
+    b40 &= ImmTestBranchBit40_mask;
+    return b5 | b40;
+  }
+
+  // Data Processing encoding.
+  static Instr SF(Register rd) {
+      return rd.Is64Bits() ? SixtyFourBits : ThirtyTwoBits;
+  }
+
+  static Instr ImmAddSub(int64_t imm) {
+    VIXL_ASSERT(IsImmAddSub(imm));
+    if (is_uint12(imm)) {  // No shift required.
+      return imm << ImmAddSub_offset;
+    } else {
+      return ((imm >> 12) << ImmAddSub_offset) | (1 << ShiftAddSub_offset);
+    }
+  }
+
+  static Instr ImmS(unsigned imms, unsigned reg_size) {
+    VIXL_ASSERT(((reg_size == kXRegSize) && is_uint6(imms)) ||
+           ((reg_size == kWRegSize) && is_uint5(imms)));
+    USE(reg_size);
+    return imms << ImmS_offset;
+  }
+
+  static Instr ImmR(unsigned immr, unsigned reg_size) {
+    VIXL_ASSERT(((reg_size == kXRegSize) && is_uint6(immr)) ||
+           ((reg_size == kWRegSize) && is_uint5(immr)));
+    USE(reg_size);
+    VIXL_ASSERT(is_uint6(immr));
+    return immr << ImmR_offset;
+  }
+
+  static Instr ImmSetBits(unsigned imms, unsigned reg_size) {
+    VIXL_ASSERT((reg_size == kWRegSize) || (reg_size == kXRegSize));
+    VIXL_ASSERT(is_uint6(imms));
+    VIXL_ASSERT((reg_size == kXRegSize) || is_uint6(imms + 3));
+    USE(reg_size);
+    return imms << ImmSetBits_offset;
+  }
+
+  static Instr ImmRotate(unsigned immr, unsigned reg_size) {
+    VIXL_ASSERT((reg_size == kWRegSize) || (reg_size == kXRegSize));
+    VIXL_ASSERT(((reg_size == kXRegSize) && is_uint6(immr)) ||
+           ((reg_size == kWRegSize) && is_uint5(immr)));
+    USE(reg_size);
+    return immr << ImmRotate_offset;
+  }
+
+  static Instr ImmLLiteral(int imm19) {
+    VIXL_ASSERT(is_int19(imm19));
+    return truncate_to_int19(imm19) << ImmLLiteral_offset;
+  }
+
+  static Instr BitN(unsigned bitn, unsigned reg_size) {
+    VIXL_ASSERT((reg_size == kWRegSize) || (reg_size == kXRegSize));
+    VIXL_ASSERT((reg_size == kXRegSize) || (bitn == 0));
+    USE(reg_size);
+    return bitn << BitN_offset;
+  }
+
+  static Instr ShiftDP(Shift shift) {
+    VIXL_ASSERT(shift == LSL || shift == LSR || shift == ASR || shift == ROR);
+    return shift << ShiftDP_offset;
+  }
+
+  static Instr ImmDPShift(unsigned amount) {
+    VIXL_ASSERT(is_uint6(amount));
+    return amount << ImmDPShift_offset;
+  }
+
+  static Instr ExtendMode(Extend extend) {
+    return extend << ExtendMode_offset;
+  }
+
+  static Instr ImmExtendShift(unsigned left_shift) {
+    VIXL_ASSERT(left_shift <= 4);
+    return left_shift << ImmExtendShift_offset;
+  }
+
+  static Instr ImmCondCmp(unsigned imm) {
+    VIXL_ASSERT(is_uint5(imm));
+    return imm << ImmCondCmp_offset;
+  }
+
+  static Instr Nzcv(StatusFlags nzcv) {
+    return ((nzcv >> Flags_offset) & 0xf) << Nzcv_offset;
+  }
+
+  // MemOperand offset encoding.
+  static Instr ImmLSUnsigned(int imm12) {
+    VIXL_ASSERT(is_uint12(imm12));
+    return imm12 << ImmLSUnsigned_offset;
+  }
+
+  static Instr ImmLS(int imm9) {
+    VIXL_ASSERT(is_int9(imm9));
+    return truncate_to_int9(imm9) << ImmLS_offset;
+  }
+
+  static Instr ImmLSPair(int imm7, LSDataSize size) {
+    VIXL_ASSERT(((imm7 >> size) << size) == imm7);
+    int scaled_imm7 = imm7 >> size;
+    VIXL_ASSERT(is_int7(scaled_imm7));
+    return truncate_to_int7(scaled_imm7) << ImmLSPair_offset;
+  }
+
+  static Instr ImmShiftLS(unsigned shift_amount) {
+    VIXL_ASSERT(is_uint1(shift_amount));
+    return shift_amount << ImmShiftLS_offset;
+  }
+
+  static Instr ImmPrefetchOperation(int imm5) {
+    VIXL_ASSERT(is_uint5(imm5));
+    return imm5 << ImmPrefetchOperation_offset;
+  }
+
+  static Instr ImmException(int imm16) {
+    VIXL_ASSERT(is_uint16(imm16));
+    return imm16 << ImmException_offset;
+  }
+
+  static Instr ImmSystemRegister(int imm15) {
+    VIXL_ASSERT(is_uint15(imm15));
+    return imm15 << ImmSystemRegister_offset;
+  }
+
+  static Instr ImmHint(int imm7) {
+    VIXL_ASSERT(is_uint7(imm7));
+    return imm7 << ImmHint_offset;
+  }
+
+  static Instr CRm(int imm4) {
+    VIXL_ASSERT(is_uint4(imm4));
+    return imm4 << CRm_offset;
+  }
+
+  static Instr ImmBarrierDomain(int imm2) {
+    VIXL_ASSERT(is_uint2(imm2));
+    return imm2 << ImmBarrierDomain_offset;
+  }
+
+  static Instr ImmBarrierType(int imm2) {
+    VIXL_ASSERT(is_uint2(imm2));
+    return imm2 << ImmBarrierType_offset;
+  }
+
+  static LSDataSize CalcLSDataSize(LoadStoreOp op) {
+    VIXL_ASSERT((SizeLS_offset + SizeLS_width) == (kInstructionSize * 8));
+    return static_cast<LSDataSize>(op >> SizeLS_offset);
+  }
+
+  // Move immediates encoding.
+  static Instr ImmMoveWide(uint64_t imm) {
+    VIXL_ASSERT(is_uint16(imm));
+    return imm << ImmMoveWide_offset;
+  }
+
+  static Instr ShiftMoveWide(int64_t shift) {
+    VIXL_ASSERT(is_uint2(shift));
+    return shift << ShiftMoveWide_offset;
+  }
+
+  // FP Immediates.
+  static Instr ImmFP32(float imm);
+  static Instr ImmFP64(double imm);
+
+  // FP register type.
+  static Instr FPType(FPRegister fd) {
+    return fd.Is64Bits() ? FP64 : FP32;
+  }
+
+  static Instr FPScale(unsigned scale) {
+    VIXL_ASSERT(is_uint6(scale));
+    return scale << FPScale_offset;
+  }
+
+  // Immediate field checking helpers.
+  static bool IsImmAddSub(int64_t immediate);
+  static bool IsImmConditionalCompare(int64_t immediate);
+  static bool IsImmFP32(float imm);
+  static bool IsImmFP64(double imm);
+  static bool IsImmLogical(uint64_t value,
+                           unsigned width,
+                           unsigned* n = NULL,
+                           unsigned* imm_s = NULL,
+                           unsigned* imm_r = NULL);
+  static bool IsImmLSPair(int64_t offset, LSDataSize size);
+  static bool IsImmLSScaled(int64_t offset, LSDataSize size);
+  static bool IsImmLSUnscaled(int64_t offset);
+  static bool IsImmMovn(uint64_t imm, unsigned reg_size);
+  static bool IsImmMovz(uint64_t imm, unsigned reg_size);
+
+  // Size of the code generated since label to the current position.
+  size_t SizeOfCodeGeneratedSince(Label* label) const {
+    VIXL_ASSERT(label->IsBound());
+    return buffer_->OffsetFrom(label->location());
+  }
+
+  size_t SizeOfCodeGenerated() const {
+    return buffer_->CursorOffset();
+  }
+
+  size_t BufferCapacity() const { return buffer_->capacity(); }
+
+  size_t RemainingBufferSpace() const { return buffer_->RemainingBytes(); }
+
+  void EnsureSpaceFor(size_t amount) {
+    if (buffer_->RemainingBytes() < amount) {
+      size_t capacity = buffer_->capacity();
+      size_t size = buffer_->CursorOffset();
+      do {
+        // TODO(all): refine.
+        capacity *= 2;
+      } while ((capacity - size) <  amount);
+      buffer_->Grow(capacity);
+    }
+  }
+
+#ifdef VIXL_DEBUG
+  void AcquireBuffer() {
+    VIXL_ASSERT(buffer_monitor_ >= 0);
+    buffer_monitor_++;
+  }
+
+  void ReleaseBuffer() {
+    buffer_monitor_--;
+    VIXL_ASSERT(buffer_monitor_ >= 0);
+  }
+#endif
+
+  PositionIndependentCodeOption pic() const {
+    return pic_;
+  }
+
+  bool AllowPageOffsetDependentCode() const {
+    return (pic() == PageOffsetDependentCode) ||
+           (pic() == PositionDependentCode);
+  }
+
+  static const Register& AppropriateZeroRegFor(const CPURegister& reg) {
+    return reg.Is64Bits() ? xzr : wzr;
+  }
+
+
+ protected:
+  void LoadStore(const CPURegister& rt,
+                 const MemOperand& addr,
+                 LoadStoreOp op,
+                 LoadStoreScalingOption option = PreferScaledOffset);
+
+  void LoadStorePair(const CPURegister& rt,
+                     const CPURegister& rt2,
+                     const MemOperand& addr,
+                     LoadStorePairOp op);
+
+  void Prefetch(PrefetchOperation op,
+                const MemOperand& addr,
+                LoadStoreScalingOption option = PreferScaledOffset);
+
+  // TODO(all): The third parameter should be passed by reference but gcc 4.8.2
+  // reports a bogus uninitialised warning then.
+  void Logical(const Register& rd,
+               const Register& rn,
+               const Operand operand,
+               LogicalOp op);
+  void LogicalImmediate(const Register& rd,
+                        const Register& rn,
+                        unsigned n,
+                        unsigned imm_s,
+                        unsigned imm_r,
+                        LogicalOp op);
+
+  void ConditionalCompare(const Register& rn,
+                          const Operand& operand,
+                          StatusFlags nzcv,
+                          Condition cond,
+                          ConditionalCompareOp op);
+
+  void AddSubWithCarry(const Register& rd,
+                       const Register& rn,
+                       const Operand& operand,
+                       FlagsUpdate S,
+                       AddSubWithCarryOp op);
+
+
+  // Functions for emulating operands not directly supported by the instruction
+  // set.
+  void EmitShift(const Register& rd,
+                 const Register& rn,
+                 Shift shift,
+                 unsigned amount);
+  void EmitExtendShift(const Register& rd,
+                       const Register& rn,
+                       Extend extend,
+                       unsigned left_shift);
+
+  void AddSub(const Register& rd,
+              const Register& rn,
+              const Operand& operand,
+              FlagsUpdate S,
+              AddSubOp op);
+
+  // Find an appropriate LoadStoreOp or LoadStorePairOp for the specified
+  // registers. Only simple loads are supported; sign- and zero-extension (such
+  // as in LDPSW_x or LDRB_w) are not supported.
+  static LoadStoreOp LoadOpFor(const CPURegister& rt);
+  static LoadStorePairOp LoadPairOpFor(const CPURegister& rt,
+                                       const CPURegister& rt2);
+  static LoadStoreOp StoreOpFor(const CPURegister& rt);
+  static LoadStorePairOp StorePairOpFor(const CPURegister& rt,
+                                        const CPURegister& rt2);
+  static LoadStorePairNonTemporalOp LoadPairNonTemporalOpFor(
+    const CPURegister& rt, const CPURegister& rt2);
+  static LoadStorePairNonTemporalOp StorePairNonTemporalOpFor(
+    const CPURegister& rt, const CPURegister& rt2);
+  static LoadLiteralOp LoadLiteralOpFor(const CPURegister& rt);
+
+
+ private:
+  // Instruction helpers.
+  void MoveWide(const Register& rd,
+                uint64_t imm,
+                int shift,
+                MoveWideImmediateOp mov_op);
+  void DataProcShiftedRegister(const Register& rd,
+                               const Register& rn,
+                               const Operand& operand,
+                               FlagsUpdate S,
+                               Instr op);
+  void DataProcExtendedRegister(const Register& rd,
+                                const Register& rn,
+                                const Operand& operand,
+                                FlagsUpdate S,
+                                Instr op);
+  void LoadStorePairNonTemporal(const CPURegister& rt,
+                                const CPURegister& rt2,
+                                const MemOperand& addr,
+                                LoadStorePairNonTemporalOp op);
+  void LoadLiteral(const CPURegister& rt, uint64_t imm, LoadLiteralOp op);
+  void ConditionalSelect(const Register& rd,
+                         const Register& rn,
+                         const Register& rm,
+                         Condition cond,
+                         ConditionalSelectOp op);
+  void DataProcessing1Source(const Register& rd,
+                             const Register& rn,
+                             DataProcessing1SourceOp op);
+  void DataProcessing3Source(const Register& rd,
+                             const Register& rn,
+                             const Register& rm,
+                             const Register& ra,
+                             DataProcessing3SourceOp op);
+  void FPDataProcessing1Source(const FPRegister& fd,
+                               const FPRegister& fn,
+                               FPDataProcessing1SourceOp op);
+  void FPDataProcessing2Source(const FPRegister& fd,
+                               const FPRegister& fn,
+                               const FPRegister& fm,
+                               FPDataProcessing2SourceOp op);
+  void FPDataProcessing3Source(const FPRegister& fd,
+                               const FPRegister& fn,
+                               const FPRegister& fm,
+                               const FPRegister& fa,
+                               FPDataProcessing3SourceOp op);
+
+  // Encode the specified MemOperand for the specified access size and scaling
+  // preference.
+  Instr LoadStoreMemOperand(const MemOperand& addr,
+                            LSDataSize size,
+                            LoadStoreScalingOption option);
+
+  // Link the current (not-yet-emitted) instruction to the specified label, then
+  // return an offset to be encoded in the instruction. If the label is not yet
+  // bound, an offset of 0 is returned.
+  ptrdiff_t LinkAndGetByteOffsetTo(Label * label);
+  ptrdiff_t LinkAndGetInstructionOffsetTo(Label * label);
+  ptrdiff_t LinkAndGetPageOffsetTo(Label * label);
+
+  // A common implementation for the LinkAndGet<Type>OffsetTo helpers.
+  template <int element_shift>
+  ptrdiff_t LinkAndGetOffsetTo(Label* label);
+
+  // Literal load offset are in words (32-bit).
+  ptrdiff_t LinkAndGetWordOffsetTo(RawLiteral* literal);
+
+  // Emit the instruction in buffer_.
+  void Emit(Instr instruction) {
+    VIXL_STATIC_ASSERT(sizeof(instruction) == kInstructionSize);
+    VIXL_ASSERT(buffer_monitor_ > 0);
+    buffer_->Emit32(instruction);
+  }
+
+  // Buffer where the code is emitted.
+  CodeBuffer* buffer_;
+  PositionIndependentCodeOption pic_;
+
+#ifdef VIXL_DEBUG
+  int64_t buffer_monitor_;
+#endif
+};
+
+
+// All Assembler emits MUST acquire/release the underlying code buffer. The
+// helper scope below will do so and optionally ensure the buffer is big enough
+// to receive the emit. It is possible to request the scope not to perform any
+// checks (kNoCheck) if for example it is known in advance the buffer size is
+// adequate or there is some other size checking mechanism in place.
+class CodeBufferCheckScope {
+ public:
+  // Tell whether or not the scope needs to ensure the associated CodeBuffer
+  // has enough space for the requested size.
+  enum CheckPolicy {
+    kNoCheck,
+    kCheck
+  };
+
+  // Tell whether or not the scope should assert the amount of code emitted
+  // within the scope is consistent with the requested amount.
+  enum AssertPolicy {
+    kNoAssert,    // No assert required.
+    kExactSize,   // The code emitted must be exactly size bytes.
+    kMaximumSize  // The code emitted must be at most size bytes.
+  };
+
+  CodeBufferCheckScope(Assembler* assm,
+                       size_t size,
+                       CheckPolicy check_policy = kCheck,
+                       AssertPolicy assert_policy = kMaximumSize)
+      : assm_(assm) {
+    if (check_policy == kCheck) assm->EnsureSpaceFor(size);
+#ifdef VIXL_DEBUG
+    assm->bind(&start_);
+    size_ = size;
+    assert_policy_ = assert_policy;
+    assm->AcquireBuffer();
+#else
+    USE(assert_policy);
+#endif
+  }
+
+  // This is a shortcut for CodeBufferCheckScope(assm, 0, kNoCheck, kNoAssert).
+  explicit CodeBufferCheckScope(Assembler* assm) : assm_(assm) {
+#ifdef VIXL_DEBUG
+    size_ = 0;
+    assert_policy_ = kNoAssert;
+    assm->AcquireBuffer();
+#endif
+  }
+
+  ~CodeBufferCheckScope() {
+#ifdef VIXL_DEBUG
+    assm_->ReleaseBuffer();
+    switch (assert_policy_) {
+      case kNoAssert: break;
+      case kExactSize:
+        VIXL_ASSERT(assm_->SizeOfCodeGeneratedSince(&start_) == size_);
+        break;
+      case kMaximumSize:
+        VIXL_ASSERT(assm_->SizeOfCodeGeneratedSince(&start_) <= size_);
+        break;
+      default:
+        VIXL_UNREACHABLE();
+    }
+#endif
+  }
+
+ protected:
+  Assembler* assm_;
+#ifdef VIXL_DEBUG
+  Label start_;
+  size_t size_;
+  AssertPolicy assert_policy_;
+#endif
+};
+
+}  // namespace vixl
+
+#endif  // VIXL_A64_ASSEMBLER_A64_H_
diff --git a/qemu/disas/libvixl/a64/constants-a64.h b/qemu/disas/libvixl/a64/constants-a64.h
new file mode 100644
index 000000000..bc1a2c4b9
--- /dev/null
+++ b/qemu/disas/libvixl/a64/constants-a64.h
@@ -0,0 +1,1213 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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 VIXL_A64_CONSTANTS_A64_H_
+#define VIXL_A64_CONSTANTS_A64_H_
+
+namespace vixl {
+
+const unsigned kNumberOfRegisters = 32;
+const unsigned kNumberOfFPRegisters = 32;
+
+#define REGISTER_CODE_LIST(R)                                                  \
+R(0)  R(1)  R(2)  R(3)  R(4)  R(5)  R(6)  R(7)                                 \
+R(8)  R(9)  R(10) R(11) R(12) R(13) R(14) R(15)                                \
+R(16) R(17) R(18) R(19) R(20) R(21) R(22) R(23)                                \
+R(24) R(25) R(26) R(27) R(28) R(29) R(30) R(31)
+
+#define INSTRUCTION_FIELDS_LIST(V_)                                            \
+/* Register fields */                                                          \
+V_(Rd, 4, 0, Bits)                        /* Destination register.        */   \
+V_(Rn, 9, 5, Bits)                        /* First source register.       */   \
+V_(Rm, 20, 16, Bits)                      /* Second source register.      */   \
+V_(Ra, 14, 10, Bits)                      /* Third source register.       */   \
+V_(Rt, 4, 0, Bits)                        /* Load/store register.         */   \
+V_(Rt2, 14, 10, Bits)                     /* Load/store second register.  */   \
+V_(Rs, 20, 16, Bits)                      /* Exclusive access status.     */   \
+                                                                               \
+/* Common bits */                                                              \
+V_(SixtyFourBits, 31, 31, Bits)                                                \
+V_(FlagsUpdate, 29, 29, Bits)                                                  \
+                                                                               \
+/* PC relative addressing */                                                   \
+V_(ImmPCRelHi, 23, 5, SignedBits)                                              \
+V_(ImmPCRelLo, 30, 29, Bits)                                                   \
+                                                                               \
+/* Add/subtract/logical shift register */                                      \
+V_(ShiftDP, 23, 22, Bits)                                                      \
+V_(ImmDPShift, 15, 10, Bits)                                                   \
+                                                                               \
+/* Add/subtract immediate */                                                   \
+V_(ImmAddSub, 21, 10, Bits)                                                    \
+V_(ShiftAddSub, 23, 22, Bits)                                                  \
+                                                                               \
+/* Add/substract extend */                                                     \
+V_(ImmExtendShift, 12, 10, Bits)                                               \
+V_(ExtendMode, 15, 13, Bits)                                                   \
+                                                                               \
+/* Move wide */                                                                \
+V_(ImmMoveWide, 20, 5, Bits)                                                   \
+V_(ShiftMoveWide, 22, 21, Bits)                                                \
+                                                                               \
+/* Logical immediate, bitfield and extract */                                  \
+V_(BitN, 22, 22, Bits)                                                         \
+V_(ImmRotate, 21, 16, Bits)                                                    \
+V_(ImmSetBits, 15, 10, Bits)                                                   \
+V_(ImmR, 21, 16, Bits)                                                         \
+V_(ImmS, 15, 10, Bits)                                                         \
+                                                                               \
+/* Test and branch immediate */                                                \
+V_(ImmTestBranch, 18, 5, SignedBits)                                           \
+V_(ImmTestBranchBit40, 23, 19, Bits)                                           \
+V_(ImmTestBranchBit5, 31, 31, Bits)                                            \
+                                                                               \
+/* Conditionals */                                                             \
+V_(Condition, 15, 12, Bits)                                                    \
+V_(ConditionBranch, 3, 0, Bits)                                                \
+V_(Nzcv, 3, 0, Bits)                                                           \
+V_(ImmCondCmp, 20, 16, Bits)                                                   \
+V_(ImmCondBranch, 23, 5, SignedBits)                                           \
+                                                                               \
+/* Floating point */                                                           \
+V_(FPType, 23, 22, Bits)                                                       \
+V_(ImmFP, 20, 13, Bits)                                                        \
+V_(FPScale, 15, 10, Bits)                                                      \
+                                                                               \
+/* Load Store */                                                               \
+V_(ImmLS, 20, 12, SignedBits)                                                  \
+V_(ImmLSUnsigned, 21, 10, Bits)                                                \
+V_(ImmLSPair, 21, 15, SignedBits)                                              \
+V_(SizeLS, 31, 30, Bits)                                                       \
+V_(ImmShiftLS, 12, 12, Bits)                                                   \
+V_(ImmPrefetchOperation, 4, 0, Bits)                                           \
+V_(PrefetchHint, 4, 3, Bits)                                                   \
+V_(PrefetchTarget, 2, 1, Bits)                                                 \
+V_(PrefetchStream, 0, 0, Bits)                                                 \
+                                                                               \
+/* Other immediates */                                                         \
+V_(ImmUncondBranch, 25, 0, SignedBits)                                         \
+V_(ImmCmpBranch, 23, 5, SignedBits)                                            \
+V_(ImmLLiteral, 23, 5, SignedBits)                                             \
+V_(ImmException, 20, 5, Bits)                                                  \
+V_(ImmHint, 11, 5, Bits)                                                       \
+V_(ImmBarrierDomain, 11, 10, Bits)                                             \
+V_(ImmBarrierType, 9, 8, Bits)                                                 \
+                                                                               \
+/* System (MRS, MSR) */                                                        \
+V_(ImmSystemRegister, 19, 5, Bits)                                             \
+V_(SysO0, 19, 19, Bits)                                                        \
+V_(SysOp1, 18, 16, Bits)                                                       \
+V_(SysOp2, 7, 5, Bits)                                                         \
+V_(CRn, 15, 12, Bits)                                                          \
+V_(CRm, 11, 8, Bits)                                                           \
+                                                                               \
+/* Load-/store-exclusive */                                                    \
+V_(LdStXLoad, 22, 22, Bits)                                                    \
+V_(LdStXNotExclusive, 23, 23, Bits)                                            \
+V_(LdStXAcquireRelease, 15, 15, Bits)                                          \
+V_(LdStXSizeLog2, 31, 30, Bits)                                                \
+V_(LdStXPair, 21, 21, Bits)                                                    \
+
+
+#define SYSTEM_REGISTER_FIELDS_LIST(V_, M_)                                    \
+/* NZCV */                                                                     \
+V_(Flags, 31, 28, Bits)                                                        \
+V_(N, 31, 31, Bits)                                                            \
+V_(Z, 30, 30, Bits)                                                            \
+V_(C, 29, 29, Bits)                                                            \
+V_(V, 28, 28, Bits)                                                            \
+M_(NZCV, Flags_mask)                                                           \
+                                                                               \
+/* FPCR */                                                                     \
+V_(AHP, 26, 26, Bits)                                                          \
+V_(DN, 25, 25, Bits)                                                           \
+V_(FZ, 24, 24, Bits)                                                           \
+V_(RMode, 23, 22, Bits)                                                        \
+M_(FPCR, AHP_mask | DN_mask | FZ_mask | RMode_mask)
+
+
+// Fields offsets.
+#define DECLARE_FIELDS_OFFSETS(Name, HighBit, LowBit, X)                       \
+const int Name##_offset = LowBit;                                              \
+const int Name##_width = HighBit - LowBit + 1;                                 \
+const uint32_t Name##_mask = ((1 << Name##_width) - 1) << LowBit;
+#define NOTHING(A, B)
+INSTRUCTION_FIELDS_LIST(DECLARE_FIELDS_OFFSETS)
+SYSTEM_REGISTER_FIELDS_LIST(DECLARE_FIELDS_OFFSETS, NOTHING)
+#undef NOTHING
+#undef DECLARE_FIELDS_BITS
+
+// ImmPCRel is a compound field (not present in INSTRUCTION_FIELDS_LIST), formed
+// from ImmPCRelLo and ImmPCRelHi.
+const int ImmPCRel_mask = ImmPCRelLo_mask | ImmPCRelHi_mask;
+
+// Condition codes.
+enum Condition {
+  eq = 0,
+  ne = 1,
+  hs = 2,
+  lo = 3,
+  mi = 4,
+  pl = 5,
+  vs = 6,
+  vc = 7,
+  hi = 8,
+  ls = 9,
+  ge = 10,
+  lt = 11,
+  gt = 12,
+  le = 13,
+  al = 14,
+  nv = 15  // Behaves as always/al.
+};
+
+inline Condition InvertCondition(Condition cond) {
+  // Conditions al and nv behave identically, as "always true". They can't be
+  // inverted, because there is no "always false" condition.
+  VIXL_ASSERT((cond != al) && (cond != nv));
+  return static_cast<Condition>(cond ^ 1);
+}
+
+enum FlagsUpdate {
+  SetFlags   = 1,
+  LeaveFlags = 0
+};
+
+enum StatusFlags {
+  NoFlag    = 0,
+
+  // Derive the flag combinations from the system register bit descriptions.
+  NFlag     = N_mask,
+  ZFlag     = Z_mask,
+  CFlag     = C_mask,
+  VFlag     = V_mask,
+  NZFlag    = NFlag | ZFlag,
+  NCFlag    = NFlag | CFlag,
+  NVFlag    = NFlag | VFlag,
+  ZCFlag    = ZFlag | CFlag,
+  ZVFlag    = ZFlag | VFlag,
+  CVFlag    = CFlag | VFlag,
+  NZCFlag   = NFlag | ZFlag | CFlag,
+  NZVFlag   = NFlag | ZFlag | VFlag,
+  NCVFlag   = NFlag | CFlag | VFlag,
+  ZCVFlag   = ZFlag | CFlag | VFlag,
+  NZCVFlag  = NFlag | ZFlag | CFlag | VFlag,
+
+  // Floating-point comparison results.
+  FPEqualFlag       = ZCFlag,
+  FPLessThanFlag    = NFlag,
+  FPGreaterThanFlag = CFlag,
+  FPUnorderedFlag   = CVFlag
+};
+
+enum Shift {
+  NO_SHIFT = -1,
+  LSL = 0x0,
+  LSR = 0x1,
+  ASR = 0x2,
+  ROR = 0x3
+};
+
+enum Extend {
+  NO_EXTEND = -1,
+  UXTB      = 0,
+  UXTH      = 1,
+  UXTW      = 2,
+  UXTX      = 3,
+  SXTB      = 4,
+  SXTH      = 5,
+  SXTW      = 6,
+  SXTX      = 7
+};
+
+enum SystemHint {
+  NOP   = 0,
+  YIELD = 1,
+  WFE   = 2,
+  WFI   = 3,
+  SEV   = 4,
+  SEVL  = 5
+};
+
+enum BarrierDomain {
+  OuterShareable = 0,
+  NonShareable   = 1,
+  InnerShareable = 2,
+  FullSystem     = 3
+};
+
+enum BarrierType {
+  BarrierOther  = 0,
+  BarrierReads  = 1,
+  BarrierWrites = 2,
+  BarrierAll    = 3
+};
+
+enum PrefetchOperation {
+  PLDL1KEEP = 0x00,
+  PLDL1STRM = 0x01,
+  PLDL2KEEP = 0x02,
+  PLDL2STRM = 0x03,
+  PLDL3KEEP = 0x04,
+  PLDL3STRM = 0x05,
+
+  PLIL1KEEP = 0x08,
+  PLIL1STRM = 0x09,
+  PLIL2KEEP = 0x0a,
+  PLIL2STRM = 0x0b,
+  PLIL3KEEP = 0x0c,
+  PLIL3STRM = 0x0d,
+
+  PSTL1KEEP = 0x10,
+  PSTL1STRM = 0x11,
+  PSTL2KEEP = 0x12,
+  PSTL2STRM = 0x13,
+  PSTL3KEEP = 0x14,
+  PSTL3STRM = 0x15
+};
+
+// System/special register names.
+// This information is not encoded as one field but as the concatenation of
+// multiple fields (Op0<0>, Op1, Crn, Crm, Op2).
+enum SystemRegister {
+  NZCV = ((0x1 << SysO0_offset) |
+          (0x3 << SysOp1_offset) |
+          (0x4 << CRn_offset) |
+          (0x2 << CRm_offset) |
+          (0x0 << SysOp2_offset)) >> ImmSystemRegister_offset,
+  FPCR = ((0x1 << SysO0_offset) |
+          (0x3 << SysOp1_offset) |
+          (0x4 << CRn_offset) |
+          (0x4 << CRm_offset) |
+          (0x0 << SysOp2_offset)) >> ImmSystemRegister_offset
+};
+
+// Instruction enumerations.
+//
+// These are the masks that define a class of instructions, and the list of
+// instructions within each class. Each enumeration has a Fixed, FMask and
+// Mask value.
+//
+// Fixed: The fixed bits in this instruction class.
+// FMask: The mask used to extract the fixed bits in the class.
+// Mask:  The mask used to identify the instructions within a class.
+//
+// The enumerations can be used like this:
+//
+// VIXL_ASSERT(instr->Mask(PCRelAddressingFMask) == PCRelAddressingFixed);
+// switch(instr->Mask(PCRelAddressingMask)) {
+//   case ADR:  Format("adr 'Xd, 'AddrPCRelByte"); break;
+//   case ADRP: Format("adrp 'Xd, 'AddrPCRelPage"); break;
+//   default:   printf("Unknown instruction\n");
+// }
+
+
+// Generic fields.
+enum GenericInstrField {
+  SixtyFourBits        = 0x80000000,
+  ThirtyTwoBits        = 0x00000000,
+  FP32                 = 0x00000000,
+  FP64                 = 0x00400000
+};
+
+// PC relative addressing.
+enum PCRelAddressingOp {
+  PCRelAddressingFixed = 0x10000000,
+  PCRelAddressingFMask = 0x1F000000,
+  PCRelAddressingMask  = 0x9F000000,
+  ADR                  = PCRelAddressingFixed | 0x00000000,
+  ADRP                 = PCRelAddressingFixed | 0x80000000
+};
+
+// Add/sub (immediate, shifted and extended.)
+const int kSFOffset = 31;
+enum AddSubOp {
+  AddSubOpMask      = 0x60000000,
+  AddSubSetFlagsBit = 0x20000000,
+  ADD               = 0x00000000,
+  ADDS              = ADD | AddSubSetFlagsBit,
+  SUB               = 0x40000000,
+  SUBS              = SUB | AddSubSetFlagsBit
+};
+
+#define ADD_SUB_OP_LIST(V)  \
+  V(ADD),                   \
+  V(ADDS),                  \
+  V(SUB),                   \
+  V(SUBS)
+
+enum AddSubImmediateOp {
+  AddSubImmediateFixed = 0x11000000,
+  AddSubImmediateFMask = 0x1F000000,
+  AddSubImmediateMask  = 0xFF000000,
+  #define ADD_SUB_IMMEDIATE(A)           \
+  A##_w_imm = AddSubImmediateFixed | A,  \
+  A##_x_imm = AddSubImmediateFixed | A | SixtyFourBits
+  ADD_SUB_OP_LIST(ADD_SUB_IMMEDIATE)
+  #undef ADD_SUB_IMMEDIATE
+};
+
+enum AddSubShiftedOp {
+  AddSubShiftedFixed   = 0x0B000000,
+  AddSubShiftedFMask   = 0x1F200000,
+  AddSubShiftedMask    = 0xFF200000,
+  #define ADD_SUB_SHIFTED(A)             \
+  A##_w_shift = AddSubShiftedFixed | A,  \
+  A##_x_shift = AddSubShiftedFixed | A | SixtyFourBits
+  ADD_SUB_OP_LIST(ADD_SUB_SHIFTED)
+  #undef ADD_SUB_SHIFTED
+};
+
+enum AddSubExtendedOp {
+  AddSubExtendedFixed  = 0x0B200000,
+  AddSubExtendedFMask  = 0x1F200000,
+  AddSubExtendedMask   = 0xFFE00000,
+  #define ADD_SUB_EXTENDED(A)           \
+  A##_w_ext = AddSubExtendedFixed | A,  \
+  A##_x_ext = AddSubExtendedFixed | A | SixtyFourBits
+  ADD_SUB_OP_LIST(ADD_SUB_EXTENDED)
+  #undef ADD_SUB_EXTENDED
+};
+
+// Add/sub with carry.
+enum AddSubWithCarryOp {
+  AddSubWithCarryFixed = 0x1A000000,
+  AddSubWithCarryFMask = 0x1FE00000,
+  AddSubWithCarryMask  = 0xFFE0FC00,
+  ADC_w                = AddSubWithCarryFixed | ADD,
+  ADC_x                = AddSubWithCarryFixed | ADD | SixtyFourBits,
+  ADC                  = ADC_w,
+  ADCS_w               = AddSubWithCarryFixed | ADDS,
+  ADCS_x               = AddSubWithCarryFixed | ADDS | SixtyFourBits,
+  SBC_w                = AddSubWithCarryFixed | SUB,
+  SBC_x                = AddSubWithCarryFixed | SUB | SixtyFourBits,
+  SBC                  = SBC_w,
+  SBCS_w               = AddSubWithCarryFixed | SUBS,
+  SBCS_x               = AddSubWithCarryFixed | SUBS | SixtyFourBits
+};
+
+
+// Logical (immediate and shifted register).
+enum LogicalOp {
+  LogicalOpMask = 0x60200000,
+  NOT   = 0x00200000,
+  AND   = 0x00000000,
+  BIC   = AND | NOT,
+  ORR   = 0x20000000,
+  ORN   = ORR | NOT,
+  EOR   = 0x40000000,
+  EON   = EOR | NOT,
+  ANDS  = 0x60000000,
+  BICS  = ANDS | NOT
+};
+
+// Logical immediate.
+enum LogicalImmediateOp {
+  LogicalImmediateFixed = 0x12000000,
+  LogicalImmediateFMask = 0x1F800000,
+  LogicalImmediateMask  = 0xFF800000,
+  AND_w_imm   = LogicalImmediateFixed | AND,
+  AND_x_imm   = LogicalImmediateFixed | AND | SixtyFourBits,
+  ORR_w_imm   = LogicalImmediateFixed | ORR,
+  ORR_x_imm   = LogicalImmediateFixed | ORR | SixtyFourBits,
+  EOR_w_imm   = LogicalImmediateFixed | EOR,
+  EOR_x_imm   = LogicalImmediateFixed | EOR | SixtyFourBits,
+  ANDS_w_imm  = LogicalImmediateFixed | ANDS,
+  ANDS_x_imm  = LogicalImmediateFixed | ANDS | SixtyFourBits
+};
+
+// Logical shifted register.
+enum LogicalShiftedOp {
+  LogicalShiftedFixed = 0x0A000000,
+  LogicalShiftedFMask = 0x1F000000,
+  LogicalShiftedMask  = 0xFF200000,
+  AND_w               = LogicalShiftedFixed | AND,
+  AND_x               = LogicalShiftedFixed | AND | SixtyFourBits,
+  AND_shift           = AND_w,
+  BIC_w               = LogicalShiftedFixed | BIC,
+  BIC_x               = LogicalShiftedFixed | BIC | SixtyFourBits,
+  BIC_shift           = BIC_w,
+  ORR_w               = LogicalShiftedFixed | ORR,
+  ORR_x               = LogicalShiftedFixed | ORR | SixtyFourBits,
+  ORR_shift           = ORR_w,
+  ORN_w               = LogicalShiftedFixed | ORN,
+  ORN_x               = LogicalShiftedFixed | ORN | SixtyFourBits,
+  ORN_shift           = ORN_w,
+  EOR_w               = LogicalShiftedFixed | EOR,
+  EOR_x               = LogicalShiftedFixed | EOR | SixtyFourBits,
+  EOR_shift           = EOR_w,
+  EON_w               = LogicalShiftedFixed | EON,
+  EON_x               = LogicalShiftedFixed | EON | SixtyFourBits,
+  EON_shift           = EON_w,
+  ANDS_w              = LogicalShiftedFixed | ANDS,
+  ANDS_x              = LogicalShiftedFixed | ANDS | SixtyFourBits,
+  ANDS_shift          = ANDS_w,
+  BICS_w              = LogicalShiftedFixed | BICS,
+  BICS_x              = LogicalShiftedFixed | BICS | SixtyFourBits,
+  BICS_shift          = BICS_w
+};
+
+// Move wide immediate.
+enum MoveWideImmediateOp {
+  MoveWideImmediateFixed = 0x12800000,
+  MoveWideImmediateFMask = 0x1F800000,
+  MoveWideImmediateMask  = 0xFF800000,
+  MOVN                   = 0x00000000,
+  MOVZ                   = 0x40000000,
+  MOVK                   = 0x60000000,
+  MOVN_w                 = MoveWideImmediateFixed | MOVN,
+  MOVN_x                 = MoveWideImmediateFixed | MOVN | SixtyFourBits,
+  MOVZ_w                 = MoveWideImmediateFixed | MOVZ,
+  MOVZ_x                 = MoveWideImmediateFixed | MOVZ | SixtyFourBits,
+  MOVK_w                 = MoveWideImmediateFixed | MOVK,
+  MOVK_x                 = MoveWideImmediateFixed | MOVK | SixtyFourBits
+};
+
+// Bitfield.
+const int kBitfieldNOffset = 22;
+enum BitfieldOp {
+  BitfieldFixed = 0x13000000,
+  BitfieldFMask = 0x1F800000,
+  BitfieldMask  = 0xFF800000,
+  SBFM_w        = BitfieldFixed | 0x00000000,
+  SBFM_x        = BitfieldFixed | 0x80000000,
+  SBFM          = SBFM_w,
+  BFM_w         = BitfieldFixed | 0x20000000,
+  BFM_x         = BitfieldFixed | 0xA0000000,
+  BFM           = BFM_w,
+  UBFM_w        = BitfieldFixed | 0x40000000,
+  UBFM_x        = BitfieldFixed | 0xC0000000,
+  UBFM          = UBFM_w
+  // Bitfield N field.
+};
+
+// Extract.
+enum ExtractOp {
+  ExtractFixed = 0x13800000,
+  ExtractFMask = 0x1F800000,
+  ExtractMask  = 0xFFA00000,
+  EXTR_w       = ExtractFixed | 0x00000000,
+  EXTR_x       = ExtractFixed | 0x80000000,
+  EXTR         = EXTR_w
+};
+
+// Unconditional branch.
+enum UnconditionalBranchOp {
+  UnconditionalBranchFixed = 0x14000000,
+  UnconditionalBranchFMask = 0x7C000000,
+  UnconditionalBranchMask  = 0xFC000000,
+  B                        = UnconditionalBranchFixed | 0x00000000,
+  BL                       = UnconditionalBranchFixed | 0x80000000
+};
+
+// Unconditional branch to register.
+enum UnconditionalBranchToRegisterOp {
+  UnconditionalBranchToRegisterFixed = 0xD6000000,
+  UnconditionalBranchToRegisterFMask = 0xFE000000,
+  UnconditionalBranchToRegisterMask  = 0xFFFFFC1F,
+  BR      = UnconditionalBranchToRegisterFixed | 0x001F0000,
+  BLR     = UnconditionalBranchToRegisterFixed | 0x003F0000,
+  RET     = UnconditionalBranchToRegisterFixed | 0x005F0000
+};
+
+// Compare and branch.
+enum CompareBranchOp {
+  CompareBranchFixed = 0x34000000,
+  CompareBranchFMask = 0x7E000000,
+  CompareBranchMask  = 0xFF000000,
+  CBZ_w              = CompareBranchFixed | 0x00000000,
+  CBZ_x              = CompareBranchFixed | 0x80000000,
+  CBZ                = CBZ_w,
+  CBNZ_w             = CompareBranchFixed | 0x01000000,
+  CBNZ_x             = CompareBranchFixed | 0x81000000,
+  CBNZ               = CBNZ_w
+};
+
+// Test and branch.
+enum TestBranchOp {
+  TestBranchFixed = 0x36000000,
+  TestBranchFMask = 0x7E000000,
+  TestBranchMask  = 0x7F000000,
+  TBZ             = TestBranchFixed | 0x00000000,
+  TBNZ            = TestBranchFixed | 0x01000000
+};
+
+// Conditional branch.
+enum ConditionalBranchOp {
+  ConditionalBranchFixed = 0x54000000,
+  ConditionalBranchFMask = 0xFE000000,
+  ConditionalBranchMask  = 0xFF000010,
+  B_cond                 = ConditionalBranchFixed | 0x00000000
+};
+
+// System.
+// System instruction encoding is complicated because some instructions use op
+// and CR fields to encode parameters. To handle this cleanly, the system
+// instructions are split into more than one enum.
+
+enum SystemOp {
+  SystemFixed = 0xD5000000,
+  SystemFMask = 0xFFC00000
+};
+
+enum SystemSysRegOp {
+  SystemSysRegFixed = 0xD5100000,
+  SystemSysRegFMask = 0xFFD00000,
+  SystemSysRegMask  = 0xFFF00000,
+  MRS               = SystemSysRegFixed | 0x00200000,
+  MSR               = SystemSysRegFixed | 0x00000000
+};
+
+enum SystemHintOp {
+  SystemHintFixed = 0xD503201F,
+  SystemHintFMask = 0xFFFFF01F,
+  SystemHintMask  = 0xFFFFF01F,
+  HINT            = SystemHintFixed | 0x00000000
+};
+
+// Exception.
+enum ExceptionOp {
+  ExceptionFixed = 0xD4000000,
+  ExceptionFMask = 0xFF000000,
+  ExceptionMask  = 0xFFE0001F,
+  HLT            = ExceptionFixed | 0x00400000,
+  BRK            = ExceptionFixed | 0x00200000,
+  SVC            = ExceptionFixed | 0x00000001,
+  HVC            = ExceptionFixed | 0x00000002,
+  SMC            = ExceptionFixed | 0x00000003,
+  DCPS1          = ExceptionFixed | 0x00A00001,
+  DCPS2          = ExceptionFixed | 0x00A00002,
+  DCPS3          = ExceptionFixed | 0x00A00003
+};
+
+enum MemBarrierOp {
+  MemBarrierFixed = 0xD503309F,
+  MemBarrierFMask = 0xFFFFF09F,
+  MemBarrierMask  = 0xFFFFF0FF,
+  DSB             = MemBarrierFixed | 0x00000000,
+  DMB             = MemBarrierFixed | 0x00000020,
+  ISB             = MemBarrierFixed | 0x00000040
+};
+
+enum SystemExclusiveMonitorOp {
+  SystemExclusiveMonitorFixed = 0xD503305F,
+  SystemExclusiveMonitorFMask = 0xFFFFF0FF,
+  SystemExclusiveMonitorMask  = 0xFFFFF0FF,
+  CLREX                       = SystemExclusiveMonitorFixed
+};
+
+// Any load or store.
+enum LoadStoreAnyOp {
+  LoadStoreAnyFMask = 0x0a000000,
+  LoadStoreAnyFixed = 0x08000000
+};
+
+// Any load pair or store pair.
+enum LoadStorePairAnyOp {
+  LoadStorePairAnyFMask = 0x3a000000,
+  LoadStorePairAnyFixed = 0x28000000
+};
+
+#define LOAD_STORE_PAIR_OP_LIST(V)  \
+  V(STP, w,   0x00000000),          \
+  V(LDP, w,   0x00400000),          \
+  V(LDPSW, x, 0x40400000),          \
+  V(STP, x,   0x80000000),          \
+  V(LDP, x,   0x80400000),          \
+  V(STP, s,   0x04000000),          \
+  V(LDP, s,   0x04400000),          \
+  V(STP, d,   0x44000000),          \
+  V(LDP, d,   0x44400000)
+
+// Load/store pair (post, pre and offset.)
+enum LoadStorePairOp {
+  LoadStorePairMask = 0xC4400000,
+  LoadStorePairLBit = 1 << 22,
+  #define LOAD_STORE_PAIR(A, B, C) \
+  A##_##B = C
+  LOAD_STORE_PAIR_OP_LIST(LOAD_STORE_PAIR)
+  #undef LOAD_STORE_PAIR
+};
+
+enum LoadStorePairPostIndexOp {
+  LoadStorePairPostIndexFixed = 0x28800000,
+  LoadStorePairPostIndexFMask = 0x3B800000,
+  LoadStorePairPostIndexMask  = 0xFFC00000,
+  #define LOAD_STORE_PAIR_POST_INDEX(A, B, C)  \
+  A##_##B##_post = LoadStorePairPostIndexFixed | A##_##B
+  LOAD_STORE_PAIR_OP_LIST(LOAD_STORE_PAIR_POST_INDEX)
+  #undef LOAD_STORE_PAIR_POST_INDEX
+};
+
+enum LoadStorePairPreIndexOp {
+  LoadStorePairPreIndexFixed = 0x29800000,
+  LoadStorePairPreIndexFMask = 0x3B800000,
+  LoadStorePairPreIndexMask  = 0xFFC00000,
+  #define LOAD_STORE_PAIR_PRE_INDEX(A, B, C)  \
+  A##_##B##_pre = LoadStorePairPreIndexFixed | A##_##B
+  LOAD_STORE_PAIR_OP_LIST(LOAD_STORE_PAIR_PRE_INDEX)
+  #undef LOAD_STORE_PAIR_PRE_INDEX
+};
+
+enum LoadStorePairOffsetOp {
+  LoadStorePairOffsetFixed = 0x29000000,
+  LoadStorePairOffsetFMask = 0x3B800000,
+  LoadStorePairOffsetMask  = 0xFFC00000,
+  #define LOAD_STORE_PAIR_OFFSET(A, B, C)  \
+  A##_##B##_off = LoadStorePairOffsetFixed | A##_##B
+  LOAD_STORE_PAIR_OP_LIST(LOAD_STORE_PAIR_OFFSET)
+  #undef LOAD_STORE_PAIR_OFFSET
+};
+
+enum LoadStorePairNonTemporalOp {
+  LoadStorePairNonTemporalFixed = 0x28000000,
+  LoadStorePairNonTemporalFMask = 0x3B800000,
+  LoadStorePairNonTemporalMask  = 0xFFC00000,
+  STNP_w = LoadStorePairNonTemporalFixed | STP_w,
+  LDNP_w = LoadStorePairNonTemporalFixed | LDP_w,
+  STNP_x = LoadStorePairNonTemporalFixed | STP_x,
+  LDNP_x = LoadStorePairNonTemporalFixed | LDP_x,
+  STNP_s = LoadStorePairNonTemporalFixed | STP_s,
+  LDNP_s = LoadStorePairNonTemporalFixed | LDP_s,
+  STNP_d = LoadStorePairNonTemporalFixed | STP_d,
+  LDNP_d = LoadStorePairNonTemporalFixed | LDP_d
+};
+
+// Load literal.
+enum LoadLiteralOp {
+  LoadLiteralFixed = 0x18000000,
+  LoadLiteralFMask = 0x3B000000,
+  LoadLiteralMask  = 0xFF000000,
+  LDR_w_lit        = LoadLiteralFixed | 0x00000000,
+  LDR_x_lit        = LoadLiteralFixed | 0x40000000,
+  LDRSW_x_lit      = LoadLiteralFixed | 0x80000000,
+  PRFM_lit         = LoadLiteralFixed | 0xC0000000,
+  LDR_s_lit        = LoadLiteralFixed | 0x04000000,
+  LDR_d_lit        = LoadLiteralFixed | 0x44000000
+};
+
+#define LOAD_STORE_OP_LIST(V)     \
+  V(ST, RB, w,  0x00000000),  \
+  V(ST, RH, w,  0x40000000),  \
+  V(ST, R, w,   0x80000000),  \
+  V(ST, R, x,   0xC0000000),  \
+  V(LD, RB, w,  0x00400000),  \
+  V(LD, RH, w,  0x40400000),  \
+  V(LD, R, w,   0x80400000),  \
+  V(LD, R, x,   0xC0400000),  \
+  V(LD, RSB, x, 0x00800000),  \
+  V(LD, RSH, x, 0x40800000),  \
+  V(LD, RSW, x, 0x80800000),  \
+  V(LD, RSB, w, 0x00C00000),  \
+  V(LD, RSH, w, 0x40C00000),  \
+  V(ST, R, s,   0x84000000),  \
+  V(ST, R, d,   0xC4000000),  \
+  V(LD, R, s,   0x84400000),  \
+  V(LD, R, d,   0xC4400000)
+
+
+// Load/store (post, pre, offset and unsigned.)
+enum LoadStoreOp {
+  LoadStoreOpMask = 0xC4C00000,
+  #define LOAD_STORE(A, B, C, D)  \
+  A##B##_##C = D
+  LOAD_STORE_OP_LIST(LOAD_STORE),
+  #undef LOAD_STORE
+  PRFM = 0xC0800000
+};
+
+// Load/store unscaled offset.
+enum LoadStoreUnscaledOffsetOp {
+  LoadStoreUnscaledOffsetFixed = 0x38000000,
+  LoadStoreUnscaledOffsetFMask = 0x3B200C00,
+  LoadStoreUnscaledOffsetMask  = 0xFFE00C00,
+  PRFUM                        = LoadStoreUnscaledOffsetFixed | PRFM,
+  #define LOAD_STORE_UNSCALED(A, B, C, D)  \
+  A##U##B##_##C = LoadStoreUnscaledOffsetFixed | D
+  LOAD_STORE_OP_LIST(LOAD_STORE_UNSCALED)
+  #undef LOAD_STORE_UNSCALED
+};
+
+// Load/store post index.
+enum LoadStorePostIndex {
+  LoadStorePostIndexFixed = 0x38000400,
+  LoadStorePostIndexFMask = 0x3B200C00,
+  LoadStorePostIndexMask  = 0xFFE00C00,
+  #define LOAD_STORE_POST_INDEX(A, B, C, D)  \
+  A##B##_##C##_post = LoadStorePostIndexFixed | D
+  LOAD_STORE_OP_LIST(LOAD_STORE_POST_INDEX)
+  #undef LOAD_STORE_POST_INDEX
+};
+
+// Load/store pre index.
+enum LoadStorePreIndex {
+  LoadStorePreIndexFixed = 0x38000C00,
+  LoadStorePreIndexFMask = 0x3B200C00,
+  LoadStorePreIndexMask  = 0xFFE00C00,
+  #define LOAD_STORE_PRE_INDEX(A, B, C, D)  \
+  A##B##_##C##_pre = LoadStorePreIndexFixed | D
+  LOAD_STORE_OP_LIST(LOAD_STORE_PRE_INDEX)
+  #undef LOAD_STORE_PRE_INDEX
+};
+
+// Load/store unsigned offset.
+enum LoadStoreUnsignedOffset {
+  LoadStoreUnsignedOffsetFixed = 0x39000000,
+  LoadStoreUnsignedOffsetFMask = 0x3B000000,
+  LoadStoreUnsignedOffsetMask  = 0xFFC00000,
+  PRFM_unsigned                = LoadStoreUnsignedOffsetFixed | PRFM,
+  #define LOAD_STORE_UNSIGNED_OFFSET(A, B, C, D) \
+  A##B##_##C##_unsigned = LoadStoreUnsignedOffsetFixed | D
+  LOAD_STORE_OP_LIST(LOAD_STORE_UNSIGNED_OFFSET)
+  #undef LOAD_STORE_UNSIGNED_OFFSET
+};
+
+// Load/store register offset.
+enum LoadStoreRegisterOffset {
+  LoadStoreRegisterOffsetFixed = 0x38200800,
+  LoadStoreRegisterOffsetFMask = 0x3B200C00,
+  LoadStoreRegisterOffsetMask  = 0xFFE00C00,
+  PRFM_reg                     = LoadStoreRegisterOffsetFixed | PRFM,
+  #define LOAD_STORE_REGISTER_OFFSET(A, B, C, D) \
+  A##B##_##C##_reg = LoadStoreRegisterOffsetFixed | D
+  LOAD_STORE_OP_LIST(LOAD_STORE_REGISTER_OFFSET)
+  #undef LOAD_STORE_REGISTER_OFFSET
+};
+
+enum LoadStoreExclusive {
+  LoadStoreExclusiveFixed = 0x08000000,
+  LoadStoreExclusiveFMask = 0x3F000000,
+  LoadStoreExclusiveMask  = 0xFFE08000,
+  STXRB_w  = LoadStoreExclusiveFixed | 0x00000000,
+  STXRH_w  = LoadStoreExclusiveFixed | 0x40000000,
+  STXR_w   = LoadStoreExclusiveFixed | 0x80000000,
+  STXR_x   = LoadStoreExclusiveFixed | 0xC0000000,
+  LDXRB_w  = LoadStoreExclusiveFixed | 0x00400000,
+  LDXRH_w  = LoadStoreExclusiveFixed | 0x40400000,
+  LDXR_w   = LoadStoreExclusiveFixed | 0x80400000,
+  LDXR_x   = LoadStoreExclusiveFixed | 0xC0400000,
+  STXP_w   = LoadStoreExclusiveFixed | 0x80200000,
+  STXP_x   = LoadStoreExclusiveFixed | 0xC0200000,
+  LDXP_w   = LoadStoreExclusiveFixed | 0x80600000,
+  LDXP_x   = LoadStoreExclusiveFixed | 0xC0600000,
+  STLXRB_w = LoadStoreExclusiveFixed | 0x00008000,
+  STLXRH_w = LoadStoreExclusiveFixed | 0x40008000,
+  STLXR_w  = LoadStoreExclusiveFixed | 0x80008000,
+  STLXR_x  = LoadStoreExclusiveFixed | 0xC0008000,
+  LDAXRB_w = LoadStoreExclusiveFixed | 0x00408000,
+  LDAXRH_w = LoadStoreExclusiveFixed | 0x40408000,
+  LDAXR_w  = LoadStoreExclusiveFixed | 0x80408000,
+  LDAXR_x  = LoadStoreExclusiveFixed | 0xC0408000,
+  STLXP_w  = LoadStoreExclusiveFixed | 0x80208000,
+  STLXP_x  = LoadStoreExclusiveFixed | 0xC0208000,
+  LDAXP_w  = LoadStoreExclusiveFixed | 0x80608000,
+  LDAXP_x  = LoadStoreExclusiveFixed | 0xC0608000,
+  STLRB_w  = LoadStoreExclusiveFixed | 0x00808000,
+  STLRH_w  = LoadStoreExclusiveFixed | 0x40808000,
+  STLR_w   = LoadStoreExclusiveFixed | 0x80808000,
+  STLR_x   = LoadStoreExclusiveFixed | 0xC0808000,
+  LDARB_w  = LoadStoreExclusiveFixed | 0x00C08000,
+  LDARH_w  = LoadStoreExclusiveFixed | 0x40C08000,
+  LDAR_w   = LoadStoreExclusiveFixed | 0x80C08000,
+  LDAR_x   = LoadStoreExclusiveFixed | 0xC0C08000
+};
+
+// Conditional compare.
+enum ConditionalCompareOp {
+  ConditionalCompareMask = 0x60000000,
+  CCMN                   = 0x20000000,
+  CCMP                   = 0x60000000
+};
+
+// Conditional compare register.
+enum ConditionalCompareRegisterOp {
+  ConditionalCompareRegisterFixed = 0x1A400000,
+  ConditionalCompareRegisterFMask = 0x1FE00800,
+  ConditionalCompareRegisterMask  = 0xFFE00C10,
+  CCMN_w = ConditionalCompareRegisterFixed | CCMN,
+  CCMN_x = ConditionalCompareRegisterFixed | SixtyFourBits | CCMN,
+  CCMP_w = ConditionalCompareRegisterFixed | CCMP,
+  CCMP_x = ConditionalCompareRegisterFixed | SixtyFourBits | CCMP
+};
+
+// Conditional compare immediate.
+enum ConditionalCompareImmediateOp {
+  ConditionalCompareImmediateFixed = 0x1A400800,
+  ConditionalCompareImmediateFMask = 0x1FE00800,
+  ConditionalCompareImmediateMask  = 0xFFE00C10,
+  CCMN_w_imm = ConditionalCompareImmediateFixed | CCMN,
+  CCMN_x_imm = ConditionalCompareImmediateFixed | SixtyFourBits | CCMN,
+  CCMP_w_imm = ConditionalCompareImmediateFixed | CCMP,
+  CCMP_x_imm = ConditionalCompareImmediateFixed | SixtyFourBits | CCMP
+};
+
+// Conditional select.
+enum ConditionalSelectOp {
+  ConditionalSelectFixed = 0x1A800000,
+  ConditionalSelectFMask = 0x1FE00000,
+  ConditionalSelectMask  = 0xFFE00C00,
+  CSEL_w                 = ConditionalSelectFixed | 0x00000000,
+  CSEL_x                 = ConditionalSelectFixed | 0x80000000,
+  CSEL                   = CSEL_w,
+  CSINC_w                = ConditionalSelectFixed | 0x00000400,
+  CSINC_x                = ConditionalSelectFixed | 0x80000400,
+  CSINC                  = CSINC_w,
+  CSINV_w                = ConditionalSelectFixed | 0x40000000,
+  CSINV_x                = ConditionalSelectFixed | 0xC0000000,
+  CSINV                  = CSINV_w,
+  CSNEG_w                = ConditionalSelectFixed | 0x40000400,
+  CSNEG_x                = ConditionalSelectFixed | 0xC0000400,
+  CSNEG                  = CSNEG_w
+};
+
+// Data processing 1 source.
+enum DataProcessing1SourceOp {
+  DataProcessing1SourceFixed = 0x5AC00000,
+  DataProcessing1SourceFMask = 0x5FE00000,
+  DataProcessing1SourceMask  = 0xFFFFFC00,
+  RBIT    = DataProcessing1SourceFixed | 0x00000000,
+  RBIT_w  = RBIT,
+  RBIT_x  = RBIT | SixtyFourBits,
+  REV16   = DataProcessing1SourceFixed | 0x00000400,
+  REV16_w = REV16,
+  REV16_x = REV16 | SixtyFourBits,
+  REV     = DataProcessing1SourceFixed | 0x00000800,
+  REV_w   = REV,
+  REV32_x = REV | SixtyFourBits,
+  REV_x   = DataProcessing1SourceFixed | SixtyFourBits | 0x00000C00,
+  CLZ     = DataProcessing1SourceFixed | 0x00001000,
+  CLZ_w   = CLZ,
+  CLZ_x   = CLZ | SixtyFourBits,
+  CLS     = DataProcessing1SourceFixed | 0x00001400,
+  CLS_w   = CLS,
+  CLS_x   = CLS | SixtyFourBits
+};
+
+// Data processing 2 source.
+enum DataProcessing2SourceOp {
+  DataProcessing2SourceFixed = 0x1AC00000,
+  DataProcessing2SourceFMask = 0x5FE00000,
+  DataProcessing2SourceMask  = 0xFFE0FC00,
+  UDIV_w  = DataProcessing2SourceFixed | 0x00000800,
+  UDIV_x  = DataProcessing2SourceFixed | 0x80000800,
+  UDIV    = UDIV_w,
+  SDIV_w  = DataProcessing2SourceFixed | 0x00000C00,
+  SDIV_x  = DataProcessing2SourceFixed | 0x80000C00,
+  SDIV    = SDIV_w,
+  LSLV_w  = DataProcessing2SourceFixed | 0x00002000,
+  LSLV_x  = DataProcessing2SourceFixed | 0x80002000,
+  LSLV    = LSLV_w,
+  LSRV_w  = DataProcessing2SourceFixed | 0x00002400,
+  LSRV_x  = DataProcessing2SourceFixed | 0x80002400,
+  LSRV    = LSRV_w,
+  ASRV_w  = DataProcessing2SourceFixed | 0x00002800,
+  ASRV_x  = DataProcessing2SourceFixed | 0x80002800,
+  ASRV    = ASRV_w,
+  RORV_w  = DataProcessing2SourceFixed | 0x00002C00,
+  RORV_x  = DataProcessing2SourceFixed | 0x80002C00,
+  RORV    = RORV_w,
+  CRC32B  = DataProcessing2SourceFixed | 0x00004000,
+  CRC32H  = DataProcessing2SourceFixed | 0x00004400,
+  CRC32W  = DataProcessing2SourceFixed | 0x00004800,
+  CRC32X  = DataProcessing2SourceFixed | SixtyFourBits | 0x00004C00,
+  CRC32CB = DataProcessing2SourceFixed | 0x00005000,
+  CRC32CH = DataProcessing2SourceFixed | 0x00005400,
+  CRC32CW = DataProcessing2SourceFixed | 0x00005800,
+  CRC32CX = DataProcessing2SourceFixed | SixtyFourBits | 0x00005C00
+};
+
+// Data processing 3 source.
+enum DataProcessing3SourceOp {
+  DataProcessing3SourceFixed = 0x1B000000,
+  DataProcessing3SourceFMask = 0x1F000000,
+  DataProcessing3SourceMask  = 0xFFE08000,
+  MADD_w                     = DataProcessing3SourceFixed | 0x00000000,
+  MADD_x                     = DataProcessing3SourceFixed | 0x80000000,
+  MADD                       = MADD_w,
+  MSUB_w                     = DataProcessing3SourceFixed | 0x00008000,
+  MSUB_x                     = DataProcessing3SourceFixed | 0x80008000,
+  MSUB                       = MSUB_w,
+  SMADDL_x                   = DataProcessing3SourceFixed | 0x80200000,
+  SMSUBL_x                   = DataProcessing3SourceFixed | 0x80208000,
+  SMULH_x                    = DataProcessing3SourceFixed | 0x80400000,
+  UMADDL_x                   = DataProcessing3SourceFixed | 0x80A00000,
+  UMSUBL_x                   = DataProcessing3SourceFixed | 0x80A08000,
+  UMULH_x                    = DataProcessing3SourceFixed | 0x80C00000
+};
+
+// Floating point compare.
+enum FPCompareOp {
+  FPCompareFixed = 0x1E202000,
+  FPCompareFMask = 0x5F203C00,
+  FPCompareMask  = 0xFFE0FC1F,
+  FCMP_s         = FPCompareFixed | 0x00000000,
+  FCMP_d         = FPCompareFixed | FP64 | 0x00000000,
+  FCMP           = FCMP_s,
+  FCMP_s_zero    = FPCompareFixed | 0x00000008,
+  FCMP_d_zero    = FPCompareFixed | FP64 | 0x00000008,
+  FCMP_zero      = FCMP_s_zero,
+  FCMPE_s        = FPCompareFixed | 0x00000010,
+  FCMPE_d        = FPCompareFixed | FP64 | 0x00000010,
+  FCMPE_s_zero   = FPCompareFixed | 0x00000018,
+  FCMPE_d_zero   = FPCompareFixed | FP64 | 0x00000018
+};
+
+// Floating point conditional compare.
+enum FPConditionalCompareOp {
+  FPConditionalCompareFixed = 0x1E200400,
+  FPConditionalCompareFMask = 0x5F200C00,
+  FPConditionalCompareMask  = 0xFFE00C10,
+  FCCMP_s                   = FPConditionalCompareFixed | 0x00000000,
+  FCCMP_d                   = FPConditionalCompareFixed | FP64 | 0x00000000,
+  FCCMP                     = FCCMP_s,
+  FCCMPE_s                  = FPConditionalCompareFixed | 0x00000010,
+  FCCMPE_d                  = FPConditionalCompareFixed | FP64 | 0x00000010,
+  FCCMPE                    = FCCMPE_s
+};
+
+// Floating point conditional select.
+enum FPConditionalSelectOp {
+  FPConditionalSelectFixed = 0x1E200C00,
+  FPConditionalSelectFMask = 0x5F200C00,
+  FPConditionalSelectMask  = 0xFFE00C00,
+  FCSEL_s                  = FPConditionalSelectFixed | 0x00000000,
+  FCSEL_d                  = FPConditionalSelectFixed | FP64 | 0x00000000,
+  FCSEL                    = FCSEL_s
+};
+
+// Floating point immediate.
+enum FPImmediateOp {
+  FPImmediateFixed = 0x1E201000,
+  FPImmediateFMask = 0x5F201C00,
+  FPImmediateMask  = 0xFFE01C00,
+  FMOV_s_imm       = FPImmediateFixed | 0x00000000,
+  FMOV_d_imm       = FPImmediateFixed | FP64 | 0x00000000
+};
+
+// Floating point data processing 1 source.
+enum FPDataProcessing1SourceOp {
+  FPDataProcessing1SourceFixed = 0x1E204000,
+  FPDataProcessing1SourceFMask = 0x5F207C00,
+  FPDataProcessing1SourceMask  = 0xFFFFFC00,
+  FMOV_s   = FPDataProcessing1SourceFixed | 0x00000000,
+  FMOV_d   = FPDataProcessing1SourceFixed | FP64 | 0x00000000,
+  FMOV     = FMOV_s,
+  FABS_s   = FPDataProcessing1SourceFixed | 0x00008000,
+  FABS_d   = FPDataProcessing1SourceFixed | FP64 | 0x00008000,
+  FABS     = FABS_s,
+  FNEG_s   = FPDataProcessing1SourceFixed | 0x00010000,
+  FNEG_d   = FPDataProcessing1SourceFixed | FP64 | 0x00010000,
+  FNEG     = FNEG_s,
+  FSQRT_s  = FPDataProcessing1SourceFixed | 0x00018000,
+  FSQRT_d  = FPDataProcessing1SourceFixed | FP64 | 0x00018000,
+  FSQRT    = FSQRT_s,
+  FCVT_ds  = FPDataProcessing1SourceFixed | 0x00028000,
+  FCVT_sd  = FPDataProcessing1SourceFixed | FP64 | 0x00020000,
+  FRINTN_s = FPDataProcessing1SourceFixed | 0x00040000,
+  FRINTN_d = FPDataProcessing1SourceFixed | FP64 | 0x00040000,
+  FRINTN   = FRINTN_s,
+  FRINTP_s = FPDataProcessing1SourceFixed | 0x00048000,
+  FRINTP_d = FPDataProcessing1SourceFixed | FP64 | 0x00048000,
+  FRINTP   = FRINTP_s,
+  FRINTM_s = FPDataProcessing1SourceFixed | 0x00050000,
+  FRINTM_d = FPDataProcessing1SourceFixed | FP64 | 0x00050000,
+  FRINTM   = FRINTM_s,
+  FRINTZ_s = FPDataProcessing1SourceFixed | 0x00058000,
+  FRINTZ_d = FPDataProcessing1SourceFixed | FP64 | 0x00058000,
+  FRINTZ   = FRINTZ_s,
+  FRINTA_s = FPDataProcessing1SourceFixed | 0x00060000,
+  FRINTA_d = FPDataProcessing1SourceFixed | FP64 | 0x00060000,
+  FRINTA   = FRINTA_s,
+  FRINTX_s = FPDataProcessing1SourceFixed | 0x00070000,
+  FRINTX_d = FPDataProcessing1SourceFixed | FP64 | 0x00070000,
+  FRINTX   = FRINTX_s,
+  FRINTI_s = FPDataProcessing1SourceFixed | 0x00078000,
+  FRINTI_d = FPDataProcessing1SourceFixed | FP64 | 0x00078000,
+  FRINTI   = FRINTI_s
+};
+
+// Floating point data processing 2 source.
+enum FPDataProcessing2SourceOp {
+  FPDataProcessing2SourceFixed = 0x1E200800,
+  FPDataProcessing2SourceFMask = 0x5F200C00,
+  FPDataProcessing2SourceMask  = 0xFFE0FC00,
+  FMUL     = FPDataProcessing2SourceFixed | 0x00000000,
+  FMUL_s   = FMUL,
+  FMUL_d   = FMUL | FP64,
+  FDIV     = FPDataProcessing2SourceFixed | 0x00001000,
+  FDIV_s   = FDIV,
+  FDIV_d   = FDIV | FP64,
+  FADD     = FPDataProcessing2SourceFixed | 0x00002000,
+  FADD_s   = FADD,
+  FADD_d   = FADD | FP64,
+  FSUB     = FPDataProcessing2SourceFixed | 0x00003000,
+  FSUB_s   = FSUB,
+  FSUB_d   = FSUB | FP64,
+  FMAX     = FPDataProcessing2SourceFixed | 0x00004000,
+  FMAX_s   = FMAX,
+  FMAX_d   = FMAX | FP64,
+  FMIN     = FPDataProcessing2SourceFixed | 0x00005000,
+  FMIN_s   = FMIN,
+  FMIN_d   = FMIN | FP64,
+  FMAXNM   = FPDataProcessing2SourceFixed | 0x00006000,
+  FMAXNM_s = FMAXNM,
+  FMAXNM_d = FMAXNM | FP64,
+  FMINNM   = FPDataProcessing2SourceFixed | 0x00007000,
+  FMINNM_s = FMINNM,
+  FMINNM_d = FMINNM | FP64,
+  FNMUL    = FPDataProcessing2SourceFixed | 0x00008000,
+  FNMUL_s  = FNMUL,
+  FNMUL_d  = FNMUL | FP64
+};
+
+// Floating point data processing 3 source.
+enum FPDataProcessing3SourceOp {
+  FPDataProcessing3SourceFixed = 0x1F000000,
+  FPDataProcessing3SourceFMask = 0x5F000000,
+  FPDataProcessing3SourceMask  = 0xFFE08000,
+  FMADD_s                      = FPDataProcessing3SourceFixed | 0x00000000,
+  FMSUB_s                      = FPDataProcessing3SourceFixed | 0x00008000,
+  FNMADD_s                     = FPDataProcessing3SourceFixed | 0x00200000,
+  FNMSUB_s                     = FPDataProcessing3SourceFixed | 0x00208000,
+  FMADD_d                      = FPDataProcessing3SourceFixed | 0x00400000,
+  FMSUB_d                      = FPDataProcessing3SourceFixed | 0x00408000,
+  FNMADD_d                     = FPDataProcessing3SourceFixed | 0x00600000,
+  FNMSUB_d                     = FPDataProcessing3SourceFixed | 0x00608000
+};
+
+// Conversion between floating point and integer.
+enum FPIntegerConvertOp {
+  FPIntegerConvertFixed = 0x1E200000,
+  FPIntegerConvertFMask = 0x5F20FC00,
+  FPIntegerConvertMask  = 0xFFFFFC00,
+  FCVTNS    = FPIntegerConvertFixed | 0x00000000,
+  FCVTNS_ws = FCVTNS,
+  FCVTNS_xs = FCVTNS | SixtyFourBits,
+  FCVTNS_wd = FCVTNS | FP64,
+  FCVTNS_xd = FCVTNS | SixtyFourBits | FP64,
+  FCVTNU    = FPIntegerConvertFixed | 0x00010000,
+  FCVTNU_ws = FCVTNU,
+  FCVTNU_xs = FCVTNU | SixtyFourBits,
+  FCVTNU_wd = FCVTNU | FP64,
+  FCVTNU_xd = FCVTNU | SixtyFourBits | FP64,
+  FCVTPS    = FPIntegerConvertFixed | 0x00080000,
+  FCVTPS_ws = FCVTPS,
+  FCVTPS_xs = FCVTPS | SixtyFourBits,
+  FCVTPS_wd = FCVTPS | FP64,
+  FCVTPS_xd = FCVTPS | SixtyFourBits | FP64,
+  FCVTPU    = FPIntegerConvertFixed | 0x00090000,
+  FCVTPU_ws = FCVTPU,
+  FCVTPU_xs = FCVTPU | SixtyFourBits,
+  FCVTPU_wd = FCVTPU | FP64,
+  FCVTPU_xd = FCVTPU | SixtyFourBits | FP64,
+  FCVTMS    = FPIntegerConvertFixed | 0x00100000,
+  FCVTMS_ws = FCVTMS,
+  FCVTMS_xs = FCVTMS | SixtyFourBits,
+  FCVTMS_wd = FCVTMS | FP64,
+  FCVTMS_xd = FCVTMS | SixtyFourBits | FP64,
+  FCVTMU    = FPIntegerConvertFixed | 0x00110000,
+  FCVTMU_ws = FCVTMU,
+  FCVTMU_xs = FCVTMU | SixtyFourBits,
+  FCVTMU_wd = FCVTMU | FP64,
+  FCVTMU_xd = FCVTMU | SixtyFourBits | FP64,
+  FCVTZS    = FPIntegerConvertFixed | 0x00180000,
+  FCVTZS_ws = FCVTZS,
+  FCVTZS_xs = FCVTZS | SixtyFourBits,
+  FCVTZS_wd = FCVTZS | FP64,
+  FCVTZS_xd = FCVTZS | SixtyFourBits | FP64,
+  FCVTZU    = FPIntegerConvertFixed | 0x00190000,
+  FCVTZU_ws = FCVTZU,
+  FCVTZU_xs = FCVTZU | SixtyFourBits,
+  FCVTZU_wd = FCVTZU | FP64,
+  FCVTZU_xd = FCVTZU | SixtyFourBits | FP64,
+  SCVTF     = FPIntegerConvertFixed | 0x00020000,
+  SCVTF_sw  = SCVTF,
+  SCVTF_sx  = SCVTF | SixtyFourBits,
+  SCVTF_dw  = SCVTF | FP64,
+  SCVTF_dx  = SCVTF | SixtyFourBits | FP64,
+  UCVTF     = FPIntegerConvertFixed | 0x00030000,
+  UCVTF_sw  = UCVTF,
+  UCVTF_sx  = UCVTF | SixtyFourBits,
+  UCVTF_dw  = UCVTF | FP64,
+  UCVTF_dx  = UCVTF | SixtyFourBits | FP64,
+  FCVTAS    = FPIntegerConvertFixed | 0x00040000,
+  FCVTAS_ws = FCVTAS,
+  FCVTAS_xs = FCVTAS | SixtyFourBits,
+  FCVTAS_wd = FCVTAS | FP64,
+  FCVTAS_xd = FCVTAS | SixtyFourBits | FP64,
+  FCVTAU    = FPIntegerConvertFixed | 0x00050000,
+  FCVTAU_ws = FCVTAU,
+  FCVTAU_xs = FCVTAU | SixtyFourBits,
+  FCVTAU_wd = FCVTAU | FP64,
+  FCVTAU_xd = FCVTAU | SixtyFourBits | FP64,
+  FMOV_ws   = FPIntegerConvertFixed | 0x00060000,
+  FMOV_sw   = FPIntegerConvertFixed | 0x00070000,
+  FMOV_xd   = FMOV_ws | SixtyFourBits | FP64,
+  FMOV_dx   = FMOV_sw | SixtyFourBits | FP64
+};
+
+// Conversion between fixed point and floating point.
+enum FPFixedPointConvertOp {
+  FPFixedPointConvertFixed = 0x1E000000,
+  FPFixedPointConvertFMask = 0x5F200000,
+  FPFixedPointConvertMask  = 0xFFFF0000,
+  FCVTZS_fixed    = FPFixedPointConvertFixed | 0x00180000,
+  FCVTZS_ws_fixed = FCVTZS_fixed,
+  FCVTZS_xs_fixed = FCVTZS_fixed | SixtyFourBits,
+  FCVTZS_wd_fixed = FCVTZS_fixed | FP64,
+  FCVTZS_xd_fixed = FCVTZS_fixed | SixtyFourBits | FP64,
+  FCVTZU_fixed    = FPFixedPointConvertFixed | 0x00190000,
+  FCVTZU_ws_fixed = FCVTZU_fixed,
+  FCVTZU_xs_fixed = FCVTZU_fixed | SixtyFourBits,
+  FCVTZU_wd_fixed = FCVTZU_fixed | FP64,
+  FCVTZU_xd_fixed = FCVTZU_fixed | SixtyFourBits | FP64,
+  SCVTF_fixed     = FPFixedPointConvertFixed | 0x00020000,
+  SCVTF_sw_fixed  = SCVTF_fixed,
+  SCVTF_sx_fixed  = SCVTF_fixed | SixtyFourBits,
+  SCVTF_dw_fixed  = SCVTF_fixed | FP64,
+  SCVTF_dx_fixed  = SCVTF_fixed | SixtyFourBits | FP64,
+  UCVTF_fixed     = FPFixedPointConvertFixed | 0x00030000,
+  UCVTF_sw_fixed  = UCVTF_fixed,
+  UCVTF_sx_fixed  = UCVTF_fixed | SixtyFourBits,
+  UCVTF_dw_fixed  = UCVTF_fixed | FP64,
+  UCVTF_dx_fixed  = UCVTF_fixed | SixtyFourBits | FP64
+};
+
+// Unimplemented and unallocated instructions. These are defined to make fixed
+// bit assertion easier.
+enum UnimplementedOp {
+  UnimplementedFixed = 0x00000000,
+  UnimplementedFMask = 0x00000000
+};
+
+enum UnallocatedOp {
+  UnallocatedFixed = 0x00000000,
+  UnallocatedFMask = 0x00000000
+};
+
+}  // namespace vixl
+
+#endif  // VIXL_A64_CONSTANTS_A64_H_
diff --git a/qemu/disas/libvixl/a64/cpu-a64.h b/qemu/disas/libvixl/a64/cpu-a64.h
new file mode 100644
index 000000000..59b7974a1
--- /dev/null
+++ b/qemu/disas/libvixl/a64/cpu-a64.h
@@ -0,0 +1,83 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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 VIXL_CPU_A64_H
+#define VIXL_CPU_A64_H
+
+#include "globals.h"
+#include "instructions-a64.h"
+
+namespace vixl {
+
+class CPU {
+ public:
+  // Initialise CPU support.
+  static void SetUp();
+
+  // Ensures the data at a given address and with a given size is the same for
+  // the I and D caches. I and D caches are not automatically coherent on ARM
+  // so this operation is required before any dynamically generated code can
+  // safely run.
+  static void EnsureIAndDCacheCoherency(void *address, size_t length);
+
+  // Handle tagged pointers.
+  template <typename T>
+  static T SetPointerTag(T pointer, uint64_t tag) {
+    VIXL_ASSERT(is_uintn(kAddressTagWidth, tag));
+
+    // Use C-style casts to get static_cast behaviour for integral types (T),
+    // and reinterpret_cast behaviour for other types.
+
+    uint64_t raw = (uint64_t)pointer;
+    VIXL_STATIC_ASSERT(sizeof(pointer) == sizeof(raw));
+
+    raw = (raw & ~kAddressTagMask) | (tag << kAddressTagOffset);
+    return (T)raw;
+  }
+
+  template <typename T>
+  static uint64_t GetPointerTag(T pointer) {
+    // Use C-style casts to get static_cast behaviour for integral types (T),
+    // and reinterpret_cast behaviour for other types.
+
+    uint64_t raw = (uint64_t)pointer;
+    VIXL_STATIC_ASSERT(sizeof(pointer) == sizeof(raw));
+
+    return (raw & kAddressTagMask) >> kAddressTagOffset;
+  }
+
+ private:
+  // Return the content of the cache type register.
+  static uint32_t GetCacheType();
+
+  // I and D cache line size in bytes.
+  static unsigned icache_line_size_;
+  static unsigned dcache_line_size_;
+};
+
+}  // namespace vixl
+
+#endif  // VIXL_CPU_A64_H
diff --git a/qemu/disas/libvixl/a64/decoder-a64.cc b/qemu/disas/libvixl/a64/decoder-a64.cc
new file mode 100644
index 000000000..82591ca30
--- /dev/null
+++ b/qemu/disas/libvixl/a64/decoder-a64.cc
@@ -0,0 +1,707 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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.
+
+#include "globals.h"
+#include "utils.h"
+#include "a64/decoder-a64.h"
+
+namespace vixl {
+
+void Decoder::DecodeInstruction(const Instruction *instr) {
+  if (instr->Bits(28, 27) == 0) {
+    VisitUnallocated(instr);
+  } else {
+    switch (instr->Bits(27, 24)) {
+      // 0:   PC relative addressing.
+      case 0x0: DecodePCRelAddressing(instr); break;
+
+      // 1:   Add/sub immediate.
+      case 0x1: DecodeAddSubImmediate(instr); break;
+
+      // A:   Logical shifted register.
+      //      Add/sub with carry.
+      //      Conditional compare register.
+      //      Conditional compare immediate.
+      //      Conditional select.
+      //      Data processing 1 source.
+      //      Data processing 2 source.
+      // B:   Add/sub shifted register.
+      //      Add/sub extended register.
+      //      Data processing 3 source.
+      case 0xA:
+      case 0xB: DecodeDataProcessing(instr); break;
+
+      // 2:   Logical immediate.
+      //      Move wide immediate.
+      case 0x2: DecodeLogical(instr); break;
+
+      // 3:   Bitfield.
+      //      Extract.
+      case 0x3: DecodeBitfieldExtract(instr); break;
+
+      // 4:   Unconditional branch immediate.
+      //      Exception generation.
+      //      Compare and branch immediate.
+      // 5:   Compare and branch immediate.
+      //      Conditional branch.
+      //      System.
+      // 6,7: Unconditional branch.
+      //      Test and branch immediate.
+      case 0x4:
+      case 0x5:
+      case 0x6:
+      case 0x7: DecodeBranchSystemException(instr); break;
+
+      // 8,9: Load/store register pair post-index.
+      //      Load register literal.
+      //      Load/store register unscaled immediate.
+      //      Load/store register immediate post-index.
+      //      Load/store register immediate pre-index.
+      //      Load/store register offset.
+      //      Load/store exclusive.
+      // C,D: Load/store register pair offset.
+      //      Load/store register pair pre-index.
+      //      Load/store register unsigned immediate.
+      //      Advanced SIMD.
+      case 0x8:
+      case 0x9:
+      case 0xC:
+      case 0xD: DecodeLoadStore(instr); break;
+
+      // E:   FP fixed point conversion.
+      //      FP integer conversion.
+      //      FP data processing 1 source.
+      //      FP compare.
+      //      FP immediate.
+      //      FP data processing 2 source.
+      //      FP conditional compare.
+      //      FP conditional select.
+      //      Advanced SIMD.
+      // F:   FP data processing 3 source.
+      //      Advanced SIMD.
+      case 0xE:
+      case 0xF: DecodeFP(instr); break;
+    }
+  }
+}
+
+void Decoder::AppendVisitor(DecoderVisitor* new_visitor) {
+  visitors_.push_back(new_visitor);
+}
+
+
+void Decoder::PrependVisitor(DecoderVisitor* new_visitor) {
+  visitors_.push_front(new_visitor);
+}
+
+
+void Decoder::InsertVisitorBefore(DecoderVisitor* new_visitor,
+                                  DecoderVisitor* registered_visitor) {
+  std::list<DecoderVisitor*>::iterator it;
+  for (it = visitors_.begin(); it != visitors_.end(); it++) {
+    if (*it == registered_visitor) {
+      visitors_.insert(it, new_visitor);
+      return;
+    }
+  }
+  // We reached the end of the list. The last element must be
+  // registered_visitor.
+  VIXL_ASSERT(*it == registered_visitor);
+  visitors_.insert(it, new_visitor);
+}
+
+
+void Decoder::InsertVisitorAfter(DecoderVisitor* new_visitor,
+                                 DecoderVisitor* registered_visitor) {
+  std::list<DecoderVisitor*>::iterator it;
+  for (it = visitors_.begin(); it != visitors_.end(); it++) {
+    if (*it == registered_visitor) {
+      it++;
+      visitors_.insert(it, new_visitor);
+      return;
+    }
+  }
+  // We reached the end of the list. The last element must be
+  // registered_visitor.
+  VIXL_ASSERT(*it == registered_visitor);
+  visitors_.push_back(new_visitor);
+}
+
+
+void Decoder::RemoveVisitor(DecoderVisitor* visitor) {
+  visitors_.remove(visitor);
+}
+
+
+void Decoder::DecodePCRelAddressing(const Instruction* instr) {
+  VIXL_ASSERT(instr->Bits(27, 24) == 0x0);
+  // We know bit 28 is set, as <b28:b27> = 0 is filtered out at the top level
+  // decode.
+  VIXL_ASSERT(instr->Bit(28) == 0x1);
+  VisitPCRelAddressing(instr);
+}
+
+
+void Decoder::DecodeBranchSystemException(const Instruction* instr) {
+  VIXL_ASSERT((instr->Bits(27, 24) == 0x4) ||
+              (instr->Bits(27, 24) == 0x5) ||
+              (instr->Bits(27, 24) == 0x6) ||
+              (instr->Bits(27, 24) == 0x7) );
+
+  switch (instr->Bits(31, 29)) {
+    case 0:
+    case 4: {
+      VisitUnconditionalBranch(instr);
+      break;
+    }
+    case 1:
+    case 5: {
+      if (instr->Bit(25) == 0) {
+        VisitCompareBranch(instr);
+      } else {
+        VisitTestBranch(instr);
+      }
+      break;
+    }
+    case 2: {
+      if (instr->Bit(25) == 0) {
+        if ((instr->Bit(24) == 0x1) ||
+            (instr->Mask(0x01000010) == 0x00000010)) {
+          VisitUnallocated(instr);
+        } else {
+          VisitConditionalBranch(instr);
+        }
+      } else {
+        VisitUnallocated(instr);
+      }
+      break;
+    }
+    case 6: {
+      if (instr->Bit(25) == 0) {
+        if (instr->Bit(24) == 0) {
+          if ((instr->Bits(4, 2) != 0) ||
+              (instr->Mask(0x00E0001D) == 0x00200001) ||
+              (instr->Mask(0x00E0001D) == 0x00400001) ||
+              (instr->Mask(0x00E0001E) == 0x00200002) ||
+              (instr->Mask(0x00E0001E) == 0x00400002) ||
+              (instr->Mask(0x00E0001C) == 0x00600000) ||
+              (instr->Mask(0x00E0001C) == 0x00800000) ||
+              (instr->Mask(0x00E0001F) == 0x00A00000) ||
+              (instr->Mask(0x00C0001C) == 0x00C00000)) {
+            VisitUnallocated(instr);
+          } else {
+            VisitException(instr);
+          }
+        } else {
+          if (instr->Bits(23, 22) == 0) {
+            const Instr masked_003FF0E0 = instr->Mask(0x003FF0E0);
+            if ((instr->Bits(21, 19) == 0x4) ||
+                (masked_003FF0E0 == 0x00033000) ||
+                (masked_003FF0E0 == 0x003FF020) ||
+                (masked_003FF0E0 == 0x003FF060) ||
+                (masked_003FF0E0 == 0x003FF0E0) ||
+                (instr->Mask(0x00388000) == 0x00008000) ||
+                (instr->Mask(0x0038E000) == 0x00000000) ||
+                (instr->Mask(0x0039E000) == 0x00002000) ||
+                (instr->Mask(0x003AE000) == 0x00002000) ||
+                (instr->Mask(0x003CE000) == 0x00042000) ||
+                (instr->Mask(0x003FFFC0) == 0x000320C0) ||
+                (instr->Mask(0x003FF100) == 0x00032100) ||
+                (instr->Mask(0x003FF200) == 0x00032200) ||
+                (instr->Mask(0x003FF400) == 0x00032400) ||
+                (instr->Mask(0x003FF800) == 0x00032800) ||
+                (instr->Mask(0x0038F000) == 0x00005000) ||
+                (instr->Mask(0x0038E000) == 0x00006000)) {
+              VisitUnallocated(instr);
+            } else {
+              VisitSystem(instr);
+            }
+          } else {
+            VisitUnallocated(instr);
+          }
+        }
+      } else {
+        if ((instr->Bit(24) == 0x1) ||
+            (instr->Bits(20, 16) != 0x1F) ||
+            (instr->Bits(15, 10) != 0) ||
+            (instr->Bits(4, 0) != 0) ||
+            (instr->Bits(24, 21) == 0x3) ||
+            (instr->Bits(24, 22) == 0x3)) {
+          VisitUnallocated(instr);
+        } else {
+          VisitUnconditionalBranchToRegister(instr);
+        }
+      }
+      break;
+    }
+    case 3:
+    case 7: {
+      VisitUnallocated(instr);
+      break;
+    }
+  }
+}
+
+
+void Decoder::DecodeLoadStore(const Instruction* instr) {
+  VIXL_ASSERT((instr->Bits(27, 24) == 0x8) ||
+              (instr->Bits(27, 24) == 0x9) ||
+              (instr->Bits(27, 24) == 0xC) ||
+              (instr->Bits(27, 24) == 0xD) );
+
+  if (instr->Bit(24) == 0) {
+    if (instr->Bit(28) == 0) {
+      if (instr->Bit(29) == 0) {
+        if (instr->Bit(26) == 0) {
+          VisitLoadStoreExclusive(instr);
+        } else {
+          DecodeAdvSIMDLoadStore(instr);
+        }
+      } else {
+        if ((instr->Bits(31, 30) == 0x3) ||
+            (instr->Mask(0xC4400000) == 0x40000000)) {
+          VisitUnallocated(instr);
+        } else {
+          if (instr->Bit(23) == 0) {
+            if (instr->Mask(0xC4400000) == 0xC0400000) {
+              VisitUnallocated(instr);
+            } else {
+              VisitLoadStorePairNonTemporal(instr);
+            }
+          } else {
+            VisitLoadStorePairPostIndex(instr);
+          }
+        }
+      }
+    } else {
+      if (instr->Bit(29) == 0) {
+        if (instr->Mask(0xC4000000) == 0xC4000000) {
+          VisitUnallocated(instr);
+        } else {
+          VisitLoadLiteral(instr);
+        }
+      } else {
+        if ((instr->Mask(0x84C00000) == 0x80C00000) ||
+            (instr->Mask(0x44800000) == 0x44800000) ||
+            (instr->Mask(0x84800000) == 0x84800000)) {
+          VisitUnallocated(instr);
+        } else {
+          if (instr->Bit(21) == 0) {
+            switch (instr->Bits(11, 10)) {
+              case 0: {
+                VisitLoadStoreUnscaledOffset(instr);
+                break;
+              }
+              case 1: {
+                if (instr->Mask(0xC4C00000) == 0xC0800000) {
+                  VisitUnallocated(instr);
+                } else {
+                  VisitLoadStorePostIndex(instr);
+                }
+                break;
+              }
+              case 2: {
+                // TODO: VisitLoadStoreRegisterOffsetUnpriv.
+                VisitUnimplemented(instr);
+                break;
+              }
+              case 3: {
+                if (instr->Mask(0xC4C00000) == 0xC0800000) {
+                  VisitUnallocated(instr);
+                } else {
+                  VisitLoadStorePreIndex(instr);
+                }
+                break;
+              }
+            }
+          } else {
+            if (instr->Bits(11, 10) == 0x2) {
+              if (instr->Bit(14) == 0) {
+                VisitUnallocated(instr);
+              } else {
+                VisitLoadStoreRegisterOffset(instr);
+              }
+            } else {
+              VisitUnallocated(instr);
+            }
+          }
+        }
+      }
+    }
+  } else {
+    if (instr->Bit(28) == 0) {
+      if (instr->Bit(29) == 0) {
+        VisitUnallocated(instr);
+      } else {
+        if ((instr->Bits(31, 30) == 0x3) ||
+            (instr->Mask(0xC4400000) == 0x40000000)) {
+          VisitUnallocated(instr);
+        } else {
+          if (instr->Bit(23) == 0) {
+            VisitLoadStorePairOffset(instr);
+          } else {
+            VisitLoadStorePairPreIndex(instr);
+          }
+        }
+      }
+    } else {
+      if (instr->Bit(29) == 0) {
+        VisitUnallocated(instr);
+      } else {
+        if ((instr->Mask(0x84C00000) == 0x80C00000) ||
+            (instr->Mask(0x44800000) == 0x44800000) ||
+            (instr->Mask(0x84800000) == 0x84800000)) {
+          VisitUnallocated(instr);
+        } else {
+          VisitLoadStoreUnsignedOffset(instr);
+        }
+      }
+    }
+  }
+}
+
+
+void Decoder::DecodeLogical(const Instruction* instr) {
+  VIXL_ASSERT(instr->Bits(27, 24) == 0x2);
+
+  if (instr->Mask(0x80400000) == 0x00400000) {
+    VisitUnallocated(instr);
+  } else {
+    if (instr->Bit(23) == 0) {
+      VisitLogicalImmediate(instr);
+    } else {
+      if (instr->Bits(30, 29) == 0x1) {
+        VisitUnallocated(instr);
+      } else {
+        VisitMoveWideImmediate(instr);
+      }
+    }
+  }
+}
+
+
+void Decoder::DecodeBitfieldExtract(const Instruction* instr) {
+  VIXL_ASSERT(instr->Bits(27, 24) == 0x3);
+
+  if ((instr->Mask(0x80400000) == 0x80000000) ||
+      (instr->Mask(0x80400000) == 0x00400000) ||
+      (instr->Mask(0x80008000) == 0x00008000)) {
+    VisitUnallocated(instr);
+  } else if (instr->Bit(23) == 0) {
+    if ((instr->Mask(0x80200000) == 0x00200000) ||
+        (instr->Mask(0x60000000) == 0x60000000)) {
+      VisitUnallocated(instr);
+    } else {
+      VisitBitfield(instr);
+    }
+  } else {
+    if ((instr->Mask(0x60200000) == 0x00200000) ||
+        (instr->Mask(0x60000000) != 0x00000000)) {
+      VisitUnallocated(instr);
+    } else {
+      VisitExtract(instr);
+    }
+  }
+}
+
+
+void Decoder::DecodeAddSubImmediate(const Instruction* instr) {
+  VIXL_ASSERT(instr->Bits(27, 24) == 0x1);
+  if (instr->Bit(23) == 1) {
+    VisitUnallocated(instr);
+  } else {
+    VisitAddSubImmediate(instr);
+  }
+}
+
+
+void Decoder::DecodeDataProcessing(const Instruction* instr) {
+  VIXL_ASSERT((instr->Bits(27, 24) == 0xA) ||
+              (instr->Bits(27, 24) == 0xB));
+
+  if (instr->Bit(24) == 0) {
+    if (instr->Bit(28) == 0) {
+      if (instr->Mask(0x80008000) == 0x00008000) {
+        VisitUnallocated(instr);
+      } else {
+        VisitLogicalShifted(instr);
+      }
+    } else {
+      switch (instr->Bits(23, 21)) {
+        case 0: {
+          if (instr->Mask(0x0000FC00) != 0) {
+            VisitUnallocated(instr);
+          } else {
+            VisitAddSubWithCarry(instr);
+          }
+          break;
+        }
+        case 2: {
+          if ((instr->Bit(29) == 0) ||
+              (instr->Mask(0x00000410) != 0)) {
+            VisitUnallocated(instr);
+          } else {
+            if (instr->Bit(11) == 0) {
+              VisitConditionalCompareRegister(instr);
+            } else {
+              VisitConditionalCompareImmediate(instr);
+            }
+          }
+          break;
+        }
+        case 4: {
+          if (instr->Mask(0x20000800) != 0x00000000) {
+            VisitUnallocated(instr);
+          } else {
+            VisitConditionalSelect(instr);
+          }
+          break;
+        }
+        case 6: {
+          if (instr->Bit(29) == 0x1) {
+            VisitUnallocated(instr);
+          } else {
+            if (instr->Bit(30) == 0) {
+              if ((instr->Bit(15) == 0x1) ||
+                  (instr->Bits(15, 11) == 0) ||
+                  (instr->Bits(15, 12) == 0x1) ||
+                  (instr->Bits(15, 12) == 0x3) ||
+                  (instr->Bits(15, 13) == 0x3) ||
+                  (instr->Mask(0x8000EC00) == 0x00004C00) ||
+                  (instr->Mask(0x8000E800) == 0x80004000) ||
+                  (instr->Mask(0x8000E400) == 0x80004000)) {
+                VisitUnallocated(instr);
+              } else {
+                VisitDataProcessing2Source(instr);
+              }
+            } else {
+              if ((instr->Bit(13) == 1) ||
+                  (instr->Bits(20, 16) != 0) ||
+                  (instr->Bits(15, 14) != 0) ||
+                  (instr->Mask(0xA01FFC00) == 0x00000C00) ||
+                  (instr->Mask(0x201FF800) == 0x00001800)) {
+                VisitUnallocated(instr);
+              } else {
+                VisitDataProcessing1Source(instr);
+              }
+            }
+            break;
+          }
+        }
+        case 1:
+        case 3:
+        case 5:
+        case 7: VisitUnallocated(instr); break;
+      }
+    }
+  } else {
+    if (instr->Bit(28) == 0) {
+     if (instr->Bit(21) == 0) {
+        if ((instr->Bits(23, 22) == 0x3) ||
+            (instr->Mask(0x80008000) == 0x00008000)) {
+          VisitUnallocated(instr);
+        } else {
+          VisitAddSubShifted(instr);
+        }
+      } else {
+        if ((instr->Mask(0x00C00000) != 0x00000000) ||
+            (instr->Mask(0x00001400) == 0x00001400) ||
+            (instr->Mask(0x00001800) == 0x00001800)) {
+          VisitUnallocated(instr);
+        } else {
+          VisitAddSubExtended(instr);
+        }
+      }
+    } else {
+      if ((instr->Bit(30) == 0x1) ||
+          (instr->Bits(30, 29) == 0x1) ||
+          (instr->Mask(0xE0600000) == 0x00200000) ||
+          (instr->Mask(0xE0608000) == 0x00400000) ||
+          (instr->Mask(0x60608000) == 0x00408000) ||
+          (instr->Mask(0x60E00000) == 0x00E00000) ||
+          (instr->Mask(0x60E00000) == 0x00800000) ||
+          (instr->Mask(0x60E00000) == 0x00600000)) {
+        VisitUnallocated(instr);
+      } else {
+        VisitDataProcessing3Source(instr);
+      }
+    }
+  }
+}
+
+
+void Decoder::DecodeFP(const Instruction* instr) {
+  VIXL_ASSERT((instr->Bits(27, 24) == 0xE) ||
+              (instr->Bits(27, 24) == 0xF));
+
+  if (instr->Bit(28) == 0) {
+    DecodeAdvSIMDDataProcessing(instr);
+  } else {
+    if (instr->Bit(29) == 1) {
+      VisitUnallocated(instr);
+    } else {
+      if (instr->Bits(31, 30) == 0x3) {
+        VisitUnallocated(instr);
+      } else if (instr->Bits(31, 30) == 0x1) {
+        DecodeAdvSIMDDataProcessing(instr);
+      } else {
+        if (instr->Bit(24) == 0) {
+          if (instr->Bit(21) == 0) {
+            if ((instr->Bit(23) == 1) ||
+                (instr->Bit(18) == 1) ||
+                (instr->Mask(0x80008000) == 0x00000000) ||
+                (instr->Mask(0x000E0000) == 0x00000000) ||
+                (instr->Mask(0x000E0000) == 0x000A0000) ||
+                (instr->Mask(0x00160000) == 0x00000000) ||
+                (instr->Mask(0x00160000) == 0x00120000)) {
+              VisitUnallocated(instr);
+            } else {
+              VisitFPFixedPointConvert(instr);
+            }
+          } else {
+            if (instr->Bits(15, 10) == 32) {
+              VisitUnallocated(instr);
+            } else if (instr->Bits(15, 10) == 0) {
+              if ((instr->Bits(23, 22) == 0x3) ||
+                  (instr->Mask(0x000E0000) == 0x000A0000) ||
+                  (instr->Mask(0x000E0000) == 0x000C0000) ||
+                  (instr->Mask(0x00160000) == 0x00120000) ||
+                  (instr->Mask(0x00160000) == 0x00140000) ||
+                  (instr->Mask(0x20C40000) == 0x00800000) ||
+                  (instr->Mask(0x20C60000) == 0x00840000) ||
+                  (instr->Mask(0xA0C60000) == 0x80060000) ||
+                  (instr->Mask(0xA0C60000) == 0x00860000) ||
+                  (instr->Mask(0xA0C60000) == 0x00460000) ||
+                  (instr->Mask(0xA0CE0000) == 0x80860000) ||
+                  (instr->Mask(0xA0CE0000) == 0x804E0000) ||
+                  (instr->Mask(0xA0CE0000) == 0x000E0000) ||
+                  (instr->Mask(0xA0D60000) == 0x00160000) ||
+                  (instr->Mask(0xA0D60000) == 0x80560000) ||
+                  (instr->Mask(0xA0D60000) == 0x80960000)) {
+                VisitUnallocated(instr);
+              } else {
+                VisitFPIntegerConvert(instr);
+              }
+            } else if (instr->Bits(14, 10) == 16) {
+              const Instr masked_A0DF8000 = instr->Mask(0xA0DF8000);
+              if ((instr->Mask(0x80180000) != 0) ||
+                  (masked_A0DF8000 == 0x00020000) ||
+                  (masked_A0DF8000 == 0x00030000) ||
+                  (masked_A0DF8000 == 0x00068000) ||
+                  (masked_A0DF8000 == 0x00428000) ||
+                  (masked_A0DF8000 == 0x00430000) ||
+                  (masked_A0DF8000 == 0x00468000) ||
+                  (instr->Mask(0xA0D80000) == 0x00800000) ||
+                  (instr->Mask(0xA0DE0000) == 0x00C00000) ||
+                  (instr->Mask(0xA0DF0000) == 0x00C30000) ||
+                  (instr->Mask(0xA0DC0000) == 0x00C40000)) {
+                VisitUnallocated(instr);
+              } else {
+                VisitFPDataProcessing1Source(instr);
+              }
+            } else if (instr->Bits(13, 10) == 8) {
+              if ((instr->Bits(15, 14) != 0) ||
+                  (instr->Bits(2, 0) != 0) ||
+                  (instr->Mask(0x80800000) != 0x00000000)) {
+                VisitUnallocated(instr);
+              } else {
+                VisitFPCompare(instr);
+              }
+            } else if (instr->Bits(12, 10) == 4) {
+              if ((instr->Bits(9, 5) != 0) ||
+                  (instr->Mask(0x80800000) != 0x00000000)) {
+                VisitUnallocated(instr);
+              } else {
+                VisitFPImmediate(instr);
+              }
+            } else {
+              if (instr->Mask(0x80800000) != 0x00000000) {
+                VisitUnallocated(instr);
+              } else {
+                switch (instr->Bits(11, 10)) {
+                  case 1: {
+                    VisitFPConditionalCompare(instr);
+                    break;
+                  }
+                  case 2: {
+                    if ((instr->Bits(15, 14) == 0x3) ||
+                        (instr->Mask(0x00009000) == 0x00009000) ||
+                        (instr->Mask(0x0000A000) == 0x0000A000)) {
+                      VisitUnallocated(instr);
+                    } else {
+                      VisitFPDataProcessing2Source(instr);
+                    }
+                    break;
+                  }
+                  case 3: {
+                    VisitFPConditionalSelect(instr);
+                    break;
+                  }
+                  default: VIXL_UNREACHABLE();
+                }
+              }
+            }
+          }
+        } else {
+          // Bit 30 == 1 has been handled earlier.
+          VIXL_ASSERT(instr->Bit(30) == 0);
+          if (instr->Mask(0xA0800000) != 0) {
+            VisitUnallocated(instr);
+          } else {
+            VisitFPDataProcessing3Source(instr);
+          }
+        }
+      }
+    }
+  }
+}
+
+
+void Decoder::DecodeAdvSIMDLoadStore(const Instruction* instr) {
+  // TODO: Implement Advanced SIMD load/store instruction decode.
+  VIXL_ASSERT(instr->Bits(29, 25) == 0x6);
+  VisitUnimplemented(instr);
+}
+
+
+void Decoder::DecodeAdvSIMDDataProcessing(const Instruction* instr) {
+  // TODO: Implement Advanced SIMD data processing instruction decode.
+  VIXL_ASSERT(instr->Bits(27, 25) == 0x7);
+  VisitUnimplemented(instr);
+}
+
+
+#define DEFINE_VISITOR_CALLERS(A)                                              \
+  void Decoder::Visit##A(const Instruction *instr) {                           \
+    VIXL_ASSERT(instr->Mask(A##FMask) == A##Fixed);                            \
+    std::list<DecoderVisitor*>::iterator it;                                   \
+    for (it = visitors_.begin(); it != visitors_.end(); it++) {                \
+      (*it)->Visit##A(instr);                                                  \
+    }                                                                          \
+  }
+VISITOR_LIST(DEFINE_VISITOR_CALLERS)
+#undef DEFINE_VISITOR_CALLERS
+}  // namespace vixl
diff --git a/qemu/disas/libvixl/a64/decoder-a64.h b/qemu/disas/libvixl/a64/decoder-a64.h
new file mode 100644
index 000000000..fd08d6c1f
--- /dev/null
+++ b/qemu/disas/libvixl/a64/decoder-a64.h
@@ -0,0 +1,239 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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 VIXL_A64_DECODER_A64_H_
+#define VIXL_A64_DECODER_A64_H_
+
+#include <list>
+
+#include "globals.h"
+#include "a64/instructions-a64.h"
+
+
+// List macro containing all visitors needed by the decoder class.
+
+#define VISITOR_LIST(V)             \
+  V(PCRelAddressing)                \
+  V(AddSubImmediate)                \
+  V(LogicalImmediate)               \
+  V(MoveWideImmediate)              \
+  V(Bitfield)                       \
+  V(Extract)                        \
+  V(UnconditionalBranch)            \
+  V(UnconditionalBranchToRegister)  \
+  V(CompareBranch)                  \
+  V(TestBranch)                     \
+  V(ConditionalBranch)              \
+  V(System)                         \
+  V(Exception)                      \
+  V(LoadStorePairPostIndex)         \
+  V(LoadStorePairOffset)            \
+  V(LoadStorePairPreIndex)          \
+  V(LoadStorePairNonTemporal)       \
+  V(LoadLiteral)                    \
+  V(LoadStoreUnscaledOffset)        \
+  V(LoadStorePostIndex)             \
+  V(LoadStorePreIndex)              \
+  V(LoadStoreRegisterOffset)        \
+  V(LoadStoreUnsignedOffset)        \
+  V(LoadStoreExclusive)             \
+  V(LogicalShifted)                 \
+  V(AddSubShifted)                  \
+  V(AddSubExtended)                 \
+  V(AddSubWithCarry)                \
+  V(ConditionalCompareRegister)     \
+  V(ConditionalCompareImmediate)    \
+  V(ConditionalSelect)              \
+  V(DataProcessing1Source)          \
+  V(DataProcessing2Source)          \
+  V(DataProcessing3Source)          \
+  V(FPCompare)                      \
+  V(FPConditionalCompare)           \
+  V(FPConditionalSelect)            \
+  V(FPImmediate)                    \
+  V(FPDataProcessing1Source)        \
+  V(FPDataProcessing2Source)        \
+  V(FPDataProcessing3Source)        \
+  V(FPIntegerConvert)               \
+  V(FPFixedPointConvert)            \
+  V(Unallocated)                    \
+  V(Unimplemented)
+
+namespace vixl {
+
+// The Visitor interface. Disassembler and simulator (and other tools)
+// must provide implementations for all of these functions.
+class DecoderVisitor {
+ public:
+  enum VisitorConstness {
+    kConstVisitor,
+    kNonConstVisitor
+  };
+  explicit DecoderVisitor(VisitorConstness constness = kConstVisitor)
+      : constness_(constness) {}
+
+  virtual ~DecoderVisitor() {}
+
+  #define DECLARE(A) virtual void Visit##A(const Instruction* instr) = 0;
+  VISITOR_LIST(DECLARE)
+  #undef DECLARE
+
+  bool IsConstVisitor() const { return constness_ == kConstVisitor; }
+  Instruction* MutableInstruction(const Instruction* instr) {
+    VIXL_ASSERT(!IsConstVisitor());
+    return const_cast<Instruction*>(instr);
+  }
+
+ private:
+  const VisitorConstness constness_;
+};
+
+
+class Decoder {
+ public:
+  Decoder() {}
+
+  // Top-level wrappers around the actual decoding function.
+  void Decode(const Instruction* instr) {
+    std::list<DecoderVisitor*>::iterator it;
+    for (it = visitors_.begin(); it != visitors_.end(); it++) {
+      VIXL_ASSERT((*it)->IsConstVisitor());
+    }
+    DecodeInstruction(instr);
+  }
+  void Decode(Instruction* instr) {
+    DecodeInstruction(const_cast<const Instruction*>(instr));
+  }
+
+  // Register a new visitor class with the decoder.
+  // Decode() will call the corresponding visitor method from all registered
+  // visitor classes when decoding reaches the leaf node of the instruction
+  // decode tree.
+  // Visitors are called in order.
+  // A visitor can be registered multiple times.
+  //
+  //   d.AppendVisitor(V1);
+  //   d.AppendVisitor(V2);
+  //   d.PrependVisitor(V2);
+  //   d.AppendVisitor(V3);
+  //
+  //   d.Decode(i);
+  //
+  // will call in order visitor methods in V2, V1, V2, V3.
+  void AppendVisitor(DecoderVisitor* visitor);
+  void PrependVisitor(DecoderVisitor* visitor);
+  // These helpers register `new_visitor` before or after the first instance of
+  // `registered_visiter` in the list.
+  // So if
+  //   V1, V2, V1, V2
+  // are registered in this order in the decoder, calls to
+  //   d.InsertVisitorAfter(V3, V1);
+  //   d.InsertVisitorBefore(V4, V2);
+  // will yield the order
+  //   V1, V3, V4, V2, V1, V2
+  //
+  // For more complex modifications of the order of registered visitors, one can
+  // directly access and modify the list of visitors via the `visitors()'
+  // accessor.
+  void InsertVisitorBefore(DecoderVisitor* new_visitor,
+                           DecoderVisitor* registered_visitor);
+  void InsertVisitorAfter(DecoderVisitor* new_visitor,
+                          DecoderVisitor* registered_visitor);
+
+  // Remove all instances of a previously registered visitor class from the list
+  // of visitors stored by the decoder.
+  void RemoveVisitor(DecoderVisitor* visitor);
+
+  #define DECLARE(A) void Visit##A(const Instruction* instr);
+  VISITOR_LIST(DECLARE)
+  #undef DECLARE
+
+
+  std::list<DecoderVisitor*>* visitors() { return &visitors_; }
+
+ private:
+  // Decodes an instruction and calls the visitor functions registered with the
+  // Decoder class.
+  void DecodeInstruction(const Instruction* instr);
+
+  // Decode the PC relative addressing instruction, and call the corresponding
+  // visitors.
+  // On entry, instruction bits 27:24 = 0x0.
+  void DecodePCRelAddressing(const Instruction* instr);
+
+  // Decode the add/subtract immediate instruction, and call the correspoding
+  // visitors.
+  // On entry, instruction bits 27:24 = 0x1.
+  void DecodeAddSubImmediate(const Instruction* instr);
+
+  // Decode the branch, system command, and exception generation parts of
+  // the instruction tree, and call the corresponding visitors.
+  // On entry, instruction bits 27:24 = {0x4, 0x5, 0x6, 0x7}.
+  void DecodeBranchSystemException(const Instruction* instr);
+
+  // Decode the load and store parts of the instruction tree, and call
+  // the corresponding visitors.
+  // On entry, instruction bits 27:24 = {0x8, 0x9, 0xC, 0xD}.
+  void DecodeLoadStore(const Instruction* instr);
+
+  // Decode the logical immediate and move wide immediate parts of the
+  // instruction tree, and call the corresponding visitors.
+  // On entry, instruction bits 27:24 = 0x2.
+  void DecodeLogical(const Instruction* instr);
+
+  // Decode the bitfield and extraction parts of the instruction tree,
+  // and call the corresponding visitors.
+  // On entry, instruction bits 27:24 = 0x3.
+  void DecodeBitfieldExtract(const Instruction* instr);
+
+  // Decode the data processing parts of the instruction tree, and call the
+  // corresponding visitors.
+  // On entry, instruction bits 27:24 = {0x1, 0xA, 0xB}.
+  void DecodeDataProcessing(const Instruction* instr);
+
+  // Decode the floating point parts of the instruction tree, and call the
+  // corresponding visitors.
+  // On entry, instruction bits 27:24 = {0xE, 0xF}.
+  void DecodeFP(const Instruction* instr);
+
+  // Decode the Advanced SIMD (NEON) load/store part of the instruction tree,
+  // and call the corresponding visitors.
+  // On entry, instruction bits 29:25 = 0x6.
+  void DecodeAdvSIMDLoadStore(const Instruction* instr);
+
+  // Decode the Advanced SIMD (NEON) data processing part of the instruction
+  // tree, and call the corresponding visitors.
+  // On entry, instruction bits 27:25 = 0x7.
+  void DecodeAdvSIMDDataProcessing(const Instruction* instr);
+
+ private:
+  // Visitors are registered in a list.
+  std::list<DecoderVisitor*> visitors_;
+};
+
+}  // namespace vixl
+
+#endif  // VIXL_A64_DECODER_A64_H_
diff --git a/qemu/disas/libvixl/a64/disasm-a64.cc b/qemu/disas/libvixl/a64/disasm-a64.cc
new file mode 100644
index 000000000..f7bc2468b
--- /dev/null
+++ b/qemu/disas/libvixl/a64/disasm-a64.cc
@@ -0,0 +1,1954 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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.
+
+#include <cstdlib>
+#include "a64/disasm-a64.h"
+
+namespace vixl {
+
+Disassembler::Disassembler() {
+  buffer_size_ = 256;
+  buffer_ = reinterpret_cast<char*>(malloc(buffer_size_));
+  buffer_pos_ = 0;
+  own_buffer_ = true;
+  code_address_offset_ = 0;
+}
+
+
+Disassembler::Disassembler(char* text_buffer, int buffer_size) {
+  buffer_size_ = buffer_size;
+  buffer_ = text_buffer;
+  buffer_pos_ = 0;
+  own_buffer_ = false;
+  code_address_offset_ = 0;
+}
+
+
+Disassembler::~Disassembler() {
+  if (own_buffer_) {
+    free(buffer_);
+  }
+}
+
+
+char* Disassembler::GetOutput() {
+  return buffer_;
+}
+
+
+void Disassembler::VisitAddSubImmediate(const Instruction* instr) {
+  bool rd_is_zr = RdIsZROrSP(instr);
+  bool stack_op = (rd_is_zr || RnIsZROrSP(instr)) &&
+                  (instr->ImmAddSub() == 0) ? true : false;
+  const char *mnemonic = "";
+  const char *form = "'Rds, 'Rns, 'IAddSub";
+  const char *form_cmp = "'Rns, 'IAddSub";
+  const char *form_mov = "'Rds, 'Rns";
+
+  switch (instr->Mask(AddSubImmediateMask)) {
+    case ADD_w_imm:
+    case ADD_x_imm: {
+      mnemonic = "add";
+      if (stack_op) {
+        mnemonic = "mov";
+        form = form_mov;
+      }
+      break;
+    }
+    case ADDS_w_imm:
+    case ADDS_x_imm: {
+      mnemonic = "adds";
+      if (rd_is_zr) {
+        mnemonic = "cmn";
+        form = form_cmp;
+      }
+      break;
+    }
+    case SUB_w_imm:
+    case SUB_x_imm: mnemonic = "sub"; break;
+    case SUBS_w_imm:
+    case SUBS_x_imm: {
+      mnemonic = "subs";
+      if (rd_is_zr) {
+        mnemonic = "cmp";
+        form = form_cmp;
+      }
+      break;
+    }
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitAddSubShifted(const Instruction* instr) {
+  bool rd_is_zr = RdIsZROrSP(instr);
+  bool rn_is_zr = RnIsZROrSP(instr);
+  const char *mnemonic = "";
+  const char *form = "'Rd, 'Rn, 'Rm'HDP";
+  const char *form_cmp = "'Rn, 'Rm'HDP";
+  const char *form_neg = "'Rd, 'Rm'HDP";
+
+  switch (instr->Mask(AddSubShiftedMask)) {
+    case ADD_w_shift:
+    case ADD_x_shift: mnemonic = "add"; break;
+    case ADDS_w_shift:
+    case ADDS_x_shift: {
+      mnemonic = "adds";
+      if (rd_is_zr) {
+        mnemonic = "cmn";
+        form = form_cmp;
+      }
+      break;
+    }
+    case SUB_w_shift:
+    case SUB_x_shift: {
+      mnemonic = "sub";
+      if (rn_is_zr) {
+        mnemonic = "neg";
+        form = form_neg;
+      }
+      break;
+    }
+    case SUBS_w_shift:
+    case SUBS_x_shift: {
+      mnemonic = "subs";
+      if (rd_is_zr) {
+        mnemonic = "cmp";
+        form = form_cmp;
+      } else if (rn_is_zr) {
+        mnemonic = "negs";
+        form = form_neg;
+      }
+      break;
+    }
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitAddSubExtended(const Instruction* instr) {
+  bool rd_is_zr = RdIsZROrSP(instr);
+  const char *mnemonic = "";
+  Extend mode = static_cast<Extend>(instr->ExtendMode());
+  const char *form = ((mode == UXTX) || (mode == SXTX)) ?
+                     "'Rds, 'Rns, 'Xm'Ext" : "'Rds, 'Rns, 'Wm'Ext";
+  const char *form_cmp = ((mode == UXTX) || (mode == SXTX)) ?
+                         "'Rns, 'Xm'Ext" : "'Rns, 'Wm'Ext";
+
+  switch (instr->Mask(AddSubExtendedMask)) {
+    case ADD_w_ext:
+    case ADD_x_ext: mnemonic = "add"; break;
+    case ADDS_w_ext:
+    case ADDS_x_ext: {
+      mnemonic = "adds";
+      if (rd_is_zr) {
+        mnemonic = "cmn";
+        form = form_cmp;
+      }
+      break;
+    }
+    case SUB_w_ext:
+    case SUB_x_ext: mnemonic = "sub"; break;
+    case SUBS_w_ext:
+    case SUBS_x_ext: {
+      mnemonic = "subs";
+      if (rd_is_zr) {
+        mnemonic = "cmp";
+        form = form_cmp;
+      }
+      break;
+    }
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitAddSubWithCarry(const Instruction* instr) {
+  bool rn_is_zr = RnIsZROrSP(instr);
+  const char *mnemonic = "";
+  const char *form = "'Rd, 'Rn, 'Rm";
+  const char *form_neg = "'Rd, 'Rm";
+
+  switch (instr->Mask(AddSubWithCarryMask)) {
+    case ADC_w:
+    case ADC_x: mnemonic = "adc"; break;
+    case ADCS_w:
+    case ADCS_x: mnemonic = "adcs"; break;
+    case SBC_w:
+    case SBC_x: {
+      mnemonic = "sbc";
+      if (rn_is_zr) {
+        mnemonic = "ngc";
+        form = form_neg;
+      }
+      break;
+    }
+    case SBCS_w:
+    case SBCS_x: {
+      mnemonic = "sbcs";
+      if (rn_is_zr) {
+        mnemonic = "ngcs";
+        form = form_neg;
+      }
+      break;
+    }
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitLogicalImmediate(const Instruction* instr) {
+  bool rd_is_zr = RdIsZROrSP(instr);
+  bool rn_is_zr = RnIsZROrSP(instr);
+  const char *mnemonic = "";
+  const char *form = "'Rds, 'Rn, 'ITri";
+
+  if (instr->ImmLogical() == 0) {
+    // The immediate encoded in the instruction is not in the expected format.
+    Format(instr, "unallocated", "(LogicalImmediate)");
+    return;
+  }
+
+  switch (instr->Mask(LogicalImmediateMask)) {
+    case AND_w_imm:
+    case AND_x_imm: mnemonic = "and"; break;
+    case ORR_w_imm:
+    case ORR_x_imm: {
+      mnemonic = "orr";
+      unsigned reg_size = (instr->SixtyFourBits() == 1) ? kXRegSize
+                                                        : kWRegSize;
+      if (rn_is_zr && !IsMovzMovnImm(reg_size, instr->ImmLogical())) {
+        mnemonic = "mov";
+        form = "'Rds, 'ITri";
+      }
+      break;
+    }
+    case EOR_w_imm:
+    case EOR_x_imm: mnemonic = "eor"; break;
+    case ANDS_w_imm:
+    case ANDS_x_imm: {
+      mnemonic = "ands";
+      if (rd_is_zr) {
+        mnemonic = "tst";
+        form = "'Rn, 'ITri";
+      }
+      break;
+    }
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+bool Disassembler::IsMovzMovnImm(unsigned reg_size, uint64_t value) {
+  VIXL_ASSERT((reg_size == kXRegSize) ||
+              ((reg_size == kWRegSize) && (value <= 0xffffffff)));
+
+  // Test for movz: 16 bits set at positions 0, 16, 32 or 48.
+  if (((value & UINT64_C(0xffffffffffff0000)) == 0) ||
+      ((value & UINT64_C(0xffffffff0000ffff)) == 0) ||
+      ((value & UINT64_C(0xffff0000ffffffff)) == 0) ||
+      ((value & UINT64_C(0x0000ffffffffffff)) == 0)) {
+    return true;
+  }
+
+  // Test for movn: NOT(16 bits set at positions 0, 16, 32 or 48).
+  if ((reg_size == kXRegSize) &&
+      (((~value & UINT64_C(0xffffffffffff0000)) == 0) ||
+       ((~value & UINT64_C(0xffffffff0000ffff)) == 0) ||
+       ((~value & UINT64_C(0xffff0000ffffffff)) == 0) ||
+       ((~value & UINT64_C(0x0000ffffffffffff)) == 0))) {
+    return true;
+  }
+  if ((reg_size == kWRegSize) &&
+      (((value & 0xffff0000) == 0xffff0000) ||
+       ((value & 0x0000ffff) == 0x0000ffff))) {
+    return true;
+  }
+  return false;
+}
+
+
+void Disassembler::VisitLogicalShifted(const Instruction* instr) {
+  bool rd_is_zr = RdIsZROrSP(instr);
+  bool rn_is_zr = RnIsZROrSP(instr);
+  const char *mnemonic = "";
+  const char *form = "'Rd, 'Rn, 'Rm'HLo";
+
+  switch (instr->Mask(LogicalShiftedMask)) {
+    case AND_w:
+    case AND_x: mnemonic = "and"; break;
+    case BIC_w:
+    case BIC_x: mnemonic = "bic"; break;
+    case EOR_w:
+    case EOR_x: mnemonic = "eor"; break;
+    case EON_w:
+    case EON_x: mnemonic = "eon"; break;
+    case BICS_w:
+    case BICS_x: mnemonic = "bics"; break;
+    case ANDS_w:
+    case ANDS_x: {
+      mnemonic = "ands";
+      if (rd_is_zr) {
+        mnemonic = "tst";
+        form = "'Rn, 'Rm'HLo";
+      }
+      break;
+    }
+    case ORR_w:
+    case ORR_x: {
+      mnemonic = "orr";
+      if (rn_is_zr && (instr->ImmDPShift() == 0) && (instr->ShiftDP() == LSL)) {
+        mnemonic = "mov";
+        form = "'Rd, 'Rm";
+      }
+      break;
+    }
+    case ORN_w:
+    case ORN_x: {
+      mnemonic = "orn";
+      if (rn_is_zr) {
+        mnemonic = "mvn";
+        form = "'Rd, 'Rm'HLo";
+      }
+      break;
+    }
+    default: VIXL_UNREACHABLE();
+  }
+
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitConditionalCompareRegister(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "'Rn, 'Rm, 'INzcv, 'Cond";
+
+  switch (instr->Mask(ConditionalCompareRegisterMask)) {
+    case CCMN_w:
+    case CCMN_x: mnemonic = "ccmn"; break;
+    case CCMP_w:
+    case CCMP_x: mnemonic = "ccmp"; break;
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitConditionalCompareImmediate(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "'Rn, 'IP, 'INzcv, 'Cond";
+
+  switch (instr->Mask(ConditionalCompareImmediateMask)) {
+    case CCMN_w_imm:
+    case CCMN_x_imm: mnemonic = "ccmn"; break;
+    case CCMP_w_imm:
+    case CCMP_x_imm: mnemonic = "ccmp"; break;
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitConditionalSelect(const Instruction* instr) {
+  bool rnm_is_zr = (RnIsZROrSP(instr) && RmIsZROrSP(instr));
+  bool rn_is_rm = (instr->Rn() == instr->Rm());
+  const char *mnemonic = "";
+  const char *form = "'Rd, 'Rn, 'Rm, 'Cond";
+  const char *form_test = "'Rd, 'CInv";
+  const char *form_update = "'Rd, 'Rn, 'CInv";
+
+  Condition cond = static_cast<Condition>(instr->Condition());
+  bool invertible_cond = (cond != al) && (cond != nv);
+
+  switch (instr->Mask(ConditionalSelectMask)) {
+    case CSEL_w:
+    case CSEL_x: mnemonic = "csel"; break;
+    case CSINC_w:
+    case CSINC_x: {
+      mnemonic = "csinc";
+      if (rnm_is_zr && invertible_cond) {
+        mnemonic = "cset";
+        form = form_test;
+      } else if (rn_is_rm && invertible_cond) {
+        mnemonic = "cinc";
+        form = form_update;
+      }
+      break;
+    }
+    case CSINV_w:
+    case CSINV_x: {
+      mnemonic = "csinv";
+      if (rnm_is_zr && invertible_cond) {
+        mnemonic = "csetm";
+        form = form_test;
+      } else if (rn_is_rm && invertible_cond) {
+        mnemonic = "cinv";
+        form = form_update;
+      }
+      break;
+    }
+    case CSNEG_w:
+    case CSNEG_x: {
+      mnemonic = "csneg";
+      if (rn_is_rm && invertible_cond) {
+        mnemonic = "cneg";
+        form = form_update;
+      }
+      break;
+    }
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitBitfield(const Instruction* instr) {
+  unsigned s = instr->ImmS();
+  unsigned r = instr->ImmR();
+  unsigned rd_size_minus_1 =
+    ((instr->SixtyFourBits() == 1) ? kXRegSize : kWRegSize) - 1;
+  const char *mnemonic = "";
+  const char *form = "";
+  const char *form_shift_right = "'Rd, 'Rn, 'IBr";
+  const char *form_extend = "'Rd, 'Wn";
+  const char *form_bfiz = "'Rd, 'Rn, 'IBZ-r, 'IBs+1";
+  const char *form_bfx = "'Rd, 'Rn, 'IBr, 'IBs-r+1";
+  const char *form_lsl = "'Rd, 'Rn, 'IBZ-r";
+
+  switch (instr->Mask(BitfieldMask)) {
+    case SBFM_w:
+    case SBFM_x: {
+      mnemonic = "sbfx";
+      form = form_bfx;
+      if (r == 0) {
+        form = form_extend;
+        if (s == 7) {
+          mnemonic = "sxtb";
+        } else if (s == 15) {
+          mnemonic = "sxth";
+        } else if ((s == 31) && (instr->SixtyFourBits() == 1)) {
+          mnemonic = "sxtw";
+        } else {
+          form = form_bfx;
+        }
+      } else if (s == rd_size_minus_1) {
+        mnemonic = "asr";
+        form = form_shift_right;
+      } else if (s < r) {
+        mnemonic = "sbfiz";
+        form = form_bfiz;
+      }
+      break;
+    }
+    case UBFM_w:
+    case UBFM_x: {
+      mnemonic = "ubfx";
+      form = form_bfx;
+      if (r == 0) {
+        form = form_extend;
+        if (s == 7) {
+          mnemonic = "uxtb";
+        } else if (s == 15) {
+          mnemonic = "uxth";
+        } else {
+          form = form_bfx;
+        }
+      }
+      if (s == rd_size_minus_1) {
+        mnemonic = "lsr";
+        form = form_shift_right;
+      } else if (r == s + 1) {
+        mnemonic = "lsl";
+        form = form_lsl;
+      } else if (s < r) {
+        mnemonic = "ubfiz";
+        form = form_bfiz;
+      }
+      break;
+    }
+    case BFM_w:
+    case BFM_x: {
+      mnemonic = "bfxil";
+      form = form_bfx;
+      if (s < r) {
+        mnemonic = "bfi";
+        form = form_bfiz;
+      }
+    }
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitExtract(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "'Rd, 'Rn, 'Rm, 'IExtract";
+
+  switch (instr->Mask(ExtractMask)) {
+    case EXTR_w:
+    case EXTR_x: {
+      if (instr->Rn() == instr->Rm()) {
+        mnemonic = "ror";
+        form = "'Rd, 'Rn, 'IExtract";
+      } else {
+        mnemonic = "extr";
+      }
+      break;
+    }
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitPCRelAddressing(const Instruction* instr) {
+  switch (instr->Mask(PCRelAddressingMask)) {
+    case ADR: Format(instr, "adr", "'Xd, 'AddrPCRelByte"); break;
+    case ADRP: Format(instr, "adrp", "'Xd, 'AddrPCRelPage"); break;
+    default: Format(instr, "unimplemented", "(PCRelAddressing)");
+  }
+}
+
+
+void Disassembler::VisitConditionalBranch(const Instruction* instr) {
+  switch (instr->Mask(ConditionalBranchMask)) {
+    case B_cond: Format(instr, "b.'CBrn", "'BImmCond"); break;
+    default: VIXL_UNREACHABLE();
+  }
+}
+
+
+void Disassembler::VisitUnconditionalBranchToRegister(
+    const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "'Xn";
+
+  switch (instr->Mask(UnconditionalBranchToRegisterMask)) {
+    case BR: mnemonic = "br"; break;
+    case BLR: mnemonic = "blr"; break;
+    case RET: {
+      mnemonic = "ret";
+      if (instr->Rn() == kLinkRegCode) {
+        form = NULL;
+      }
+      break;
+    }
+    default: form = "(UnconditionalBranchToRegister)";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitUnconditionalBranch(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "'BImmUncn";
+
+  switch (instr->Mask(UnconditionalBranchMask)) {
+    case B: mnemonic = "b"; break;
+    case BL: mnemonic = "bl"; break;
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitDataProcessing1Source(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "'Rd, 'Rn";
+
+  switch (instr->Mask(DataProcessing1SourceMask)) {
+    #define FORMAT(A, B)  \
+    case A##_w:           \
+    case A##_x: mnemonic = B; break;
+    FORMAT(RBIT, "rbit");
+    FORMAT(REV16, "rev16");
+    FORMAT(REV, "rev");
+    FORMAT(CLZ, "clz");
+    FORMAT(CLS, "cls");
+    #undef FORMAT
+    case REV32_x: mnemonic = "rev32"; break;
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitDataProcessing2Source(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "'Rd, 'Rn, 'Rm";
+
+  switch (instr->Mask(DataProcessing2SourceMask)) {
+    #define FORMAT(A, B)  \
+    case A##_w:           \
+    case A##_x: mnemonic = B; break;
+    FORMAT(UDIV, "udiv");
+    FORMAT(SDIV, "sdiv");
+    FORMAT(LSLV, "lsl");
+    FORMAT(LSRV, "lsr");
+    FORMAT(ASRV, "asr");
+    FORMAT(RORV, "ror");
+    #undef FORMAT
+    default: form = "(DataProcessing2Source)";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitDataProcessing3Source(const Instruction* instr) {
+  bool ra_is_zr = RaIsZROrSP(instr);
+  const char *mnemonic = "";
+  const char *form = "'Xd, 'Wn, 'Wm, 'Xa";
+  const char *form_rrr = "'Rd, 'Rn, 'Rm";
+  const char *form_rrrr = "'Rd, 'Rn, 'Rm, 'Ra";
+  const char *form_xww = "'Xd, 'Wn, 'Wm";
+  const char *form_xxx = "'Xd, 'Xn, 'Xm";
+
+  switch (instr->Mask(DataProcessing3SourceMask)) {
+    case MADD_w:
+    case MADD_x: {
+      mnemonic = "madd";
+      form = form_rrrr;
+      if (ra_is_zr) {
+        mnemonic = "mul";
+        form = form_rrr;
+      }
+      break;
+    }
+    case MSUB_w:
+    case MSUB_x: {
+      mnemonic = "msub";
+      form = form_rrrr;
+      if (ra_is_zr) {
+        mnemonic = "mneg";
+        form = form_rrr;
+      }
+      break;
+    }
+    case SMADDL_x: {
+      mnemonic = "smaddl";
+      if (ra_is_zr) {
+        mnemonic = "smull";
+        form = form_xww;
+      }
+      break;
+    }
+    case SMSUBL_x: {
+      mnemonic = "smsubl";
+      if (ra_is_zr) {
+        mnemonic = "smnegl";
+        form = form_xww;
+      }
+      break;
+    }
+    case UMADDL_x: {
+      mnemonic = "umaddl";
+      if (ra_is_zr) {
+        mnemonic = "umull";
+        form = form_xww;
+      }
+      break;
+    }
+    case UMSUBL_x: {
+      mnemonic = "umsubl";
+      if (ra_is_zr) {
+        mnemonic = "umnegl";
+        form = form_xww;
+      }
+      break;
+    }
+    case SMULH_x: {
+      mnemonic = "smulh";
+      form = form_xxx;
+      break;
+    }
+    case UMULH_x: {
+      mnemonic = "umulh";
+      form = form_xxx;
+      break;
+    }
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitCompareBranch(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "'Rt, 'BImmCmpa";
+
+  switch (instr->Mask(CompareBranchMask)) {
+    case CBZ_w:
+    case CBZ_x: mnemonic = "cbz"; break;
+    case CBNZ_w:
+    case CBNZ_x: mnemonic = "cbnz"; break;
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitTestBranch(const Instruction* instr) {
+  const char *mnemonic = "";
+  // If the top bit of the immediate is clear, the tested register is
+  // disassembled as Wt, otherwise Xt. As the top bit of the immediate is
+  // encoded in bit 31 of the instruction, we can reuse the Rt form, which
+  // uses bit 31 (normally "sf") to choose the register size.
+  const char *form = "'Rt, 'IS, 'BImmTest";
+
+  switch (instr->Mask(TestBranchMask)) {
+    case TBZ: mnemonic = "tbz"; break;
+    case TBNZ: mnemonic = "tbnz"; break;
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitMoveWideImmediate(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "'Rd, 'IMoveImm";
+
+  // Print the shift separately for movk, to make it clear which half word will
+  // be overwritten. Movn and movz print the computed immediate, which includes
+  // shift calculation.
+  switch (instr->Mask(MoveWideImmediateMask)) {
+    case MOVN_w:
+    case MOVN_x:
+      if ((instr->ImmMoveWide()) || (instr->ShiftMoveWide() == 0)) {
+        if ((instr->SixtyFourBits() == 0) && (instr->ImmMoveWide() == 0xffff)) {
+          mnemonic = "movn";
+        } else {
+          mnemonic = "mov";
+          form = "'Rd, 'IMoveNeg";
+        }
+      } else {
+        mnemonic = "movn";
+      }
+      break;
+    case MOVZ_w:
+    case MOVZ_x:
+      if ((instr->ImmMoveWide()) || (instr->ShiftMoveWide() == 0))
+        mnemonic = "mov";
+      else
+        mnemonic = "movz";
+      break;
+    case MOVK_w:
+    case MOVK_x: mnemonic = "movk"; form = "'Rd, 'IMoveLSL"; break;
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+#define LOAD_STORE_LIST(V)    \
+  V(STRB_w, "strb", "'Wt")    \
+  V(STRH_w, "strh", "'Wt")    \
+  V(STR_w, "str", "'Wt")      \
+  V(STR_x, "str", "'Xt")      \
+  V(LDRB_w, "ldrb", "'Wt")    \
+  V(LDRH_w, "ldrh", "'Wt")    \
+  V(LDR_w, "ldr", "'Wt")      \
+  V(LDR_x, "ldr", "'Xt")      \
+  V(LDRSB_x, "ldrsb", "'Xt")  \
+  V(LDRSH_x, "ldrsh", "'Xt")  \
+  V(LDRSW_x, "ldrsw", "'Xt")  \
+  V(LDRSB_w, "ldrsb", "'Wt")  \
+  V(LDRSH_w, "ldrsh", "'Wt")  \
+  V(STR_s, "str", "'St")      \
+  V(STR_d, "str", "'Dt")      \
+  V(LDR_s, "ldr", "'St")      \
+  V(LDR_d, "ldr", "'Dt")
+
+void Disassembler::VisitLoadStorePreIndex(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "(LoadStorePreIndex)";
+
+  switch (instr->Mask(LoadStorePreIndexMask)) {
+    #define LS_PREINDEX(A, B, C) \
+    case A##_pre: mnemonic = B; form = C ", ['Xns'ILS]!"; break;
+    LOAD_STORE_LIST(LS_PREINDEX)
+    #undef LS_PREINDEX
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitLoadStorePostIndex(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "(LoadStorePostIndex)";
+
+  switch (instr->Mask(LoadStorePostIndexMask)) {
+    #define LS_POSTINDEX(A, B, C) \
+    case A##_post: mnemonic = B; form = C ", ['Xns]'ILS"; break;
+    LOAD_STORE_LIST(LS_POSTINDEX)
+    #undef LS_POSTINDEX
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitLoadStoreUnsignedOffset(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "(LoadStoreUnsignedOffset)";
+
+  switch (instr->Mask(LoadStoreUnsignedOffsetMask)) {
+    #define LS_UNSIGNEDOFFSET(A, B, C) \
+    case A##_unsigned: mnemonic = B; form = C ", ['Xns'ILU]"; break;
+    LOAD_STORE_LIST(LS_UNSIGNEDOFFSET)
+    #undef LS_UNSIGNEDOFFSET
+    case PRFM_unsigned: mnemonic = "prfm"; form = "'PrefOp, ['Xns'ILU]";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitLoadStoreRegisterOffset(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "(LoadStoreRegisterOffset)";
+
+  switch (instr->Mask(LoadStoreRegisterOffsetMask)) {
+    #define LS_REGISTEROFFSET(A, B, C) \
+    case A##_reg: mnemonic = B; form = C ", ['Xns, 'Offsetreg]"; break;
+    LOAD_STORE_LIST(LS_REGISTEROFFSET)
+    #undef LS_REGISTEROFFSET
+    case PRFM_reg: mnemonic = "prfm"; form = "'PrefOp, ['Xns, 'Offsetreg]";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitLoadStoreUnscaledOffset(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "'Wt, ['Xns'ILS]";
+  const char *form_x = "'Xt, ['Xns'ILS]";
+  const char *form_s = "'St, ['Xns'ILS]";
+  const char *form_d = "'Dt, ['Xns'ILS]";
+  const char *form_prefetch = "'PrefOp, ['Xns'ILS]";
+
+  switch (instr->Mask(LoadStoreUnscaledOffsetMask)) {
+    case STURB_w:  mnemonic = "sturb"; break;
+    case STURH_w:  mnemonic = "sturh"; break;
+    case STUR_w:   mnemonic = "stur"; break;
+    case STUR_x:   mnemonic = "stur"; form = form_x; break;
+    case STUR_s:   mnemonic = "stur"; form = form_s; break;
+    case STUR_d:   mnemonic = "stur"; form = form_d; break;
+    case LDURB_w:  mnemonic = "ldurb"; break;
+    case LDURH_w:  mnemonic = "ldurh"; break;
+    case LDUR_w:   mnemonic = "ldur"; break;
+    case LDUR_x:   mnemonic = "ldur"; form = form_x; break;
+    case LDUR_s:   mnemonic = "ldur"; form = form_s; break;
+    case LDUR_d:   mnemonic = "ldur"; form = form_d; break;
+    case LDURSB_x: form = form_x;  // Fall through.
+    case LDURSB_w: mnemonic = "ldursb"; break;
+    case LDURSH_x: form = form_x;  // Fall through.
+    case LDURSH_w: mnemonic = "ldursh"; break;
+    case LDURSW_x: mnemonic = "ldursw"; form = form_x; break;
+    case PRFUM:    mnemonic = "prfum"; form = form_prefetch; break;
+    default: form = "(LoadStoreUnscaledOffset)";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitLoadLiteral(const Instruction* instr) {
+  const char *mnemonic = "ldr";
+  const char *form = "(LoadLiteral)";
+
+  switch (instr->Mask(LoadLiteralMask)) {
+    case LDR_w_lit: form = "'Wt, 'ILLiteral 'LValue"; break;
+    case LDR_x_lit: form = "'Xt, 'ILLiteral 'LValue"; break;
+    case LDR_s_lit: form = "'St, 'ILLiteral 'LValue"; break;
+    case LDR_d_lit: form = "'Dt, 'ILLiteral 'LValue"; break;
+    case LDRSW_x_lit: {
+      mnemonic = "ldrsw";
+      form = "'Xt, 'ILLiteral 'LValue";
+      break;
+    }
+    case PRFM_lit: {
+      mnemonic = "prfm";
+      form = "'PrefOp, 'ILLiteral 'LValue";
+      break;
+    }
+    default: mnemonic = "unimplemented";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+#define LOAD_STORE_PAIR_LIST(V)         \
+  V(STP_w, "stp", "'Wt, 'Wt2", "4")     \
+  V(LDP_w, "ldp", "'Wt, 'Wt2", "4")     \
+  V(LDPSW_x, "ldpsw", "'Xt, 'Xt2", "4") \
+  V(STP_x, "stp", "'Xt, 'Xt2", "8")     \
+  V(LDP_x, "ldp", "'Xt, 'Xt2", "8")     \
+  V(STP_s, "stp", "'St, 'St2", "4")     \
+  V(LDP_s, "ldp", "'St, 'St2", "4")     \
+  V(STP_d, "stp", "'Dt, 'Dt2", "8")     \
+  V(LDP_d, "ldp", "'Dt, 'Dt2", "8")
+
+void Disassembler::VisitLoadStorePairPostIndex(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "(LoadStorePairPostIndex)";
+
+  switch (instr->Mask(LoadStorePairPostIndexMask)) {
+    #define LSP_POSTINDEX(A, B, C, D) \
+    case A##_post: mnemonic = B; form = C ", ['Xns]'ILP" D; break;
+    LOAD_STORE_PAIR_LIST(LSP_POSTINDEX)
+    #undef LSP_POSTINDEX
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitLoadStorePairPreIndex(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "(LoadStorePairPreIndex)";
+
+  switch (instr->Mask(LoadStorePairPreIndexMask)) {
+    #define LSP_PREINDEX(A, B, C, D) \
+    case A##_pre: mnemonic = B; form = C ", ['Xns'ILP" D "]!"; break;
+    LOAD_STORE_PAIR_LIST(LSP_PREINDEX)
+    #undef LSP_PREINDEX
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitLoadStorePairOffset(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "(LoadStorePairOffset)";
+
+  switch (instr->Mask(LoadStorePairOffsetMask)) {
+    #define LSP_OFFSET(A, B, C, D) \
+    case A##_off: mnemonic = B; form = C ", ['Xns'ILP" D "]"; break;
+    LOAD_STORE_PAIR_LIST(LSP_OFFSET)
+    #undef LSP_OFFSET
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitLoadStorePairNonTemporal(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form;
+
+  switch (instr->Mask(LoadStorePairNonTemporalMask)) {
+    case STNP_w: mnemonic = "stnp"; form = "'Wt, 'Wt2, ['Xns'ILP4]"; break;
+    case LDNP_w: mnemonic = "ldnp"; form = "'Wt, 'Wt2, ['Xns'ILP4]"; break;
+    case STNP_x: mnemonic = "stnp"; form = "'Xt, 'Xt2, ['Xns'ILP8]"; break;
+    case LDNP_x: mnemonic = "ldnp"; form = "'Xt, 'Xt2, ['Xns'ILP8]"; break;
+    case STNP_s: mnemonic = "stnp"; form = "'St, 'St2, ['Xns'ILP4]"; break;
+    case LDNP_s: mnemonic = "ldnp"; form = "'St, 'St2, ['Xns'ILP4]"; break;
+    case STNP_d: mnemonic = "stnp"; form = "'Dt, 'Dt2, ['Xns'ILP8]"; break;
+    case LDNP_d: mnemonic = "ldnp"; form = "'Dt, 'Dt2, ['Xns'ILP8]"; break;
+    default: form = "(LoadStorePairNonTemporal)";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitLoadStoreExclusive(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form;
+
+  switch (instr->Mask(LoadStoreExclusiveMask)) {
+    case STXRB_w: mnemonic = "stxrb"; form = "'Ws, 'Wt, ['Xns]"; break;
+    case STXRH_w: mnemonic = "stxrh"; form = "'Ws, 'Wt, ['Xns]"; break;
+    case STXR_w: mnemonic = "stxr"; form = "'Ws, 'Wt, ['Xns]"; break;
+    case STXR_x: mnemonic = "stxr"; form = "'Ws, 'Xt, ['Xns]"; break;
+    case LDXRB_w: mnemonic = "ldxrb"; form = "'Wt, ['Xns]"; break;
+    case LDXRH_w: mnemonic = "ldxrh"; form = "'Wt, ['Xns]"; break;
+    case LDXR_w: mnemonic = "ldxr"; form = "'Wt, ['Xns]"; break;
+    case LDXR_x: mnemonic = "ldxr"; form = "'Xt, ['Xns]"; break;
+    case STXP_w: mnemonic = "stxp"; form = "'Ws, 'Wt, 'Wt2, ['Xns]"; break;
+    case STXP_x: mnemonic = "stxp"; form = "'Ws, 'Xt, 'Xt2, ['Xns]"; break;
+    case LDXP_w: mnemonic = "ldxp"; form = "'Wt, 'Wt2, ['Xns]"; break;
+    case LDXP_x: mnemonic = "ldxp"; form = "'Xt, 'Xt2, ['Xns]"; break;
+    case STLXRB_w: mnemonic = "stlxrb"; form = "'Ws, 'Wt, ['Xns]"; break;
+    case STLXRH_w: mnemonic = "stlxrh"; form = "'Ws, 'Wt, ['Xns]"; break;
+    case STLXR_w: mnemonic = "stlxr"; form = "'Ws, 'Wt, ['Xns]"; break;
+    case STLXR_x: mnemonic = "stlxr"; form = "'Ws, 'Xt, ['Xns]"; break;
+    case LDAXRB_w: mnemonic = "ldaxrb"; form = "'Wt, ['Xns]"; break;
+    case LDAXRH_w: mnemonic = "ldaxrh"; form = "'Wt, ['Xns]"; break;
+    case LDAXR_w: mnemonic = "ldaxr"; form = "'Wt, ['Xns]"; break;
+    case LDAXR_x: mnemonic = "ldaxr"; form = "'Xt, ['Xns]"; break;
+    case STLXP_w: mnemonic = "stlxp"; form = "'Ws, 'Wt, 'Wt2, ['Xns]"; break;
+    case STLXP_x: mnemonic = "stlxp"; form = "'Ws, 'Xt, 'Xt2, ['Xns]"; break;
+    case LDAXP_w: mnemonic = "ldaxp"; form = "'Wt, 'Wt2, ['Xns]"; break;
+    case LDAXP_x: mnemonic = "ldaxp"; form = "'Xt, 'Xt2, ['Xns]"; break;
+    case STLRB_w: mnemonic = "stlrb"; form = "'Wt, ['Xns]"; break;
+    case STLRH_w: mnemonic = "stlrh"; form = "'Wt, ['Xns]"; break;
+    case STLR_w: mnemonic = "stlr"; form = "'Wt, ['Xns]"; break;
+    case STLR_x: mnemonic = "stlr"; form = "'Xt, ['Xns]"; break;
+    case LDARB_w: mnemonic = "ldarb"; form = "'Wt, ['Xns]"; break;
+    case LDARH_w: mnemonic = "ldarh"; form = "'Wt, ['Xns]"; break;
+    case LDAR_w: mnemonic = "ldar"; form = "'Wt, ['Xns]"; break;
+    case LDAR_x: mnemonic = "ldar"; form = "'Xt, ['Xns]"; break;
+    default: form = "(LoadStoreExclusive)";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitFPCompare(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "'Fn, 'Fm";
+  const char *form_zero = "'Fn, #0.0";
+
+  switch (instr->Mask(FPCompareMask)) {
+    case FCMP_s_zero:
+    case FCMP_d_zero: form = form_zero;  // Fall through.
+    case FCMP_s:
+    case FCMP_d: mnemonic = "fcmp"; break;
+    default: form = "(FPCompare)";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitFPConditionalCompare(const Instruction* instr) {
+  const char *mnemonic = "unmplemented";
+  const char *form = "'Fn, 'Fm, 'INzcv, 'Cond";
+
+  switch (instr->Mask(FPConditionalCompareMask)) {
+    case FCCMP_s:
+    case FCCMP_d: mnemonic = "fccmp"; break;
+    case FCCMPE_s:
+    case FCCMPE_d: mnemonic = "fccmpe"; break;
+    default: form = "(FPConditionalCompare)";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitFPConditionalSelect(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "'Fd, 'Fn, 'Fm, 'Cond";
+
+  switch (instr->Mask(FPConditionalSelectMask)) {
+    case FCSEL_s:
+    case FCSEL_d: mnemonic = "fcsel"; break;
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitFPDataProcessing1Source(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "'Fd, 'Fn";
+
+  switch (instr->Mask(FPDataProcessing1SourceMask)) {
+    #define FORMAT(A, B)  \
+    case A##_s:           \
+    case A##_d: mnemonic = B; break;
+    FORMAT(FMOV, "fmov");
+    FORMAT(FABS, "fabs");
+    FORMAT(FNEG, "fneg");
+    FORMAT(FSQRT, "fsqrt");
+    FORMAT(FRINTN, "frintn");
+    FORMAT(FRINTP, "frintp");
+    FORMAT(FRINTM, "frintm");
+    FORMAT(FRINTZ, "frintz");
+    FORMAT(FRINTA, "frinta");
+    FORMAT(FRINTX, "frintx");
+    FORMAT(FRINTI, "frinti");
+    #undef FORMAT
+    case FCVT_ds: mnemonic = "fcvt"; form = "'Dd, 'Sn"; break;
+    case FCVT_sd: mnemonic = "fcvt"; form = "'Sd, 'Dn"; break;
+    default: form = "(FPDataProcessing1Source)";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitFPDataProcessing2Source(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "'Fd, 'Fn, 'Fm";
+
+  switch (instr->Mask(FPDataProcessing2SourceMask)) {
+    #define FORMAT(A, B)  \
+    case A##_s:           \
+    case A##_d: mnemonic = B; break;
+    FORMAT(FMUL, "fmul");
+    FORMAT(FDIV, "fdiv");
+    FORMAT(FADD, "fadd");
+    FORMAT(FSUB, "fsub");
+    FORMAT(FMAX, "fmax");
+    FORMAT(FMIN, "fmin");
+    FORMAT(FMAXNM, "fmaxnm");
+    FORMAT(FMINNM, "fminnm");
+    FORMAT(FNMUL, "fnmul");
+    #undef FORMAT
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitFPDataProcessing3Source(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "'Fd, 'Fn, 'Fm, 'Fa";
+
+  switch (instr->Mask(FPDataProcessing3SourceMask)) {
+    #define FORMAT(A, B)  \
+    case A##_s:           \
+    case A##_d: mnemonic = B; break;
+    FORMAT(FMADD, "fmadd");
+    FORMAT(FMSUB, "fmsub");
+    FORMAT(FNMADD, "fnmadd");
+    FORMAT(FNMSUB, "fnmsub");
+    #undef FORMAT
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitFPImmediate(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "(FPImmediate)";
+
+  switch (instr->Mask(FPImmediateMask)) {
+    case FMOV_s_imm: mnemonic = "fmov"; form = "'Sd, 'IFPSingle"; break;
+    case FMOV_d_imm: mnemonic = "fmov"; form = "'Dd, 'IFPDouble"; break;
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitFPIntegerConvert(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "(FPIntegerConvert)";
+  const char *form_rf = "'Rd, 'Fn";
+  const char *form_fr = "'Fd, 'Rn";
+
+  switch (instr->Mask(FPIntegerConvertMask)) {
+    case FMOV_ws:
+    case FMOV_xd: mnemonic = "fmov"; form = form_rf; break;
+    case FMOV_sw:
+    case FMOV_dx: mnemonic = "fmov"; form = form_fr; break;
+    case FCVTAS_ws:
+    case FCVTAS_xs:
+    case FCVTAS_wd:
+    case FCVTAS_xd: mnemonic = "fcvtas"; form = form_rf; break;
+    case FCVTAU_ws:
+    case FCVTAU_xs:
+    case FCVTAU_wd:
+    case FCVTAU_xd: mnemonic = "fcvtau"; form = form_rf; break;
+    case FCVTMS_ws:
+    case FCVTMS_xs:
+    case FCVTMS_wd:
+    case FCVTMS_xd: mnemonic = "fcvtms"; form = form_rf; break;
+    case FCVTMU_ws:
+    case FCVTMU_xs:
+    case FCVTMU_wd:
+    case FCVTMU_xd: mnemonic = "fcvtmu"; form = form_rf; break;
+    case FCVTNS_ws:
+    case FCVTNS_xs:
+    case FCVTNS_wd:
+    case FCVTNS_xd: mnemonic = "fcvtns"; form = form_rf; break;
+    case FCVTNU_ws:
+    case FCVTNU_xs:
+    case FCVTNU_wd:
+    case FCVTNU_xd: mnemonic = "fcvtnu"; form = form_rf; break;
+    case FCVTZU_xd:
+    case FCVTZU_ws:
+    case FCVTZU_wd:
+    case FCVTZU_xs: mnemonic = "fcvtzu"; form = form_rf; break;
+    case FCVTZS_xd:
+    case FCVTZS_wd:
+    case FCVTZS_xs:
+    case FCVTZS_ws: mnemonic = "fcvtzs"; form = form_rf; break;
+    case SCVTF_sw:
+    case SCVTF_sx:
+    case SCVTF_dw:
+    case SCVTF_dx: mnemonic = "scvtf"; form = form_fr; break;
+    case UCVTF_sw:
+    case UCVTF_sx:
+    case UCVTF_dw:
+    case UCVTF_dx: mnemonic = "ucvtf"; form = form_fr; break;
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitFPFixedPointConvert(const Instruction* instr) {
+  const char *mnemonic = "";
+  const char *form = "'Rd, 'Fn, 'IFPFBits";
+  const char *form_fr = "'Fd, 'Rn, 'IFPFBits";
+
+  switch (instr->Mask(FPFixedPointConvertMask)) {
+    case FCVTZS_ws_fixed:
+    case FCVTZS_xs_fixed:
+    case FCVTZS_wd_fixed:
+    case FCVTZS_xd_fixed: mnemonic = "fcvtzs"; break;
+    case FCVTZU_ws_fixed:
+    case FCVTZU_xs_fixed:
+    case FCVTZU_wd_fixed:
+    case FCVTZU_xd_fixed: mnemonic = "fcvtzu"; break;
+    case SCVTF_sw_fixed:
+    case SCVTF_sx_fixed:
+    case SCVTF_dw_fixed:
+    case SCVTF_dx_fixed: mnemonic = "scvtf"; form = form_fr; break;
+    case UCVTF_sw_fixed:
+    case UCVTF_sx_fixed:
+    case UCVTF_dw_fixed:
+    case UCVTF_dx_fixed: mnemonic = "ucvtf"; form = form_fr; break;
+    default: VIXL_UNREACHABLE();
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitSystem(const Instruction* instr) {
+  // Some system instructions hijack their Op and Cp fields to represent a
+  // range of immediates instead of indicating a different instruction. This
+  // makes the decoding tricky.
+  const char *mnemonic = "unimplemented";
+  const char *form = "(System)";
+
+  if (instr->Mask(SystemExclusiveMonitorFMask) == SystemExclusiveMonitorFixed) {
+    switch (instr->Mask(SystemExclusiveMonitorMask)) {
+      case CLREX: {
+        mnemonic = "clrex";
+        form = (instr->CRm() == 0xf) ? NULL : "'IX";
+        break;
+      }
+    }
+  } else if (instr->Mask(SystemSysRegFMask) == SystemSysRegFixed) {
+    switch (instr->Mask(SystemSysRegMask)) {
+      case MRS: {
+        mnemonic = "mrs";
+        switch (instr->ImmSystemRegister()) {
+          case NZCV: form = "'Xt, nzcv"; break;
+          case FPCR: form = "'Xt, fpcr"; break;
+          default: form = "'Xt, (unknown)"; break;
+        }
+        break;
+      }
+      case MSR: {
+        mnemonic = "msr";
+        switch (instr->ImmSystemRegister()) {
+          case NZCV: form = "nzcv, 'Xt"; break;
+          case FPCR: form = "fpcr, 'Xt"; break;
+          default: form = "(unknown), 'Xt"; break;
+        }
+        break;
+      }
+    }
+  } else if (instr->Mask(SystemHintFMask) == SystemHintFixed) {
+    switch (instr->ImmHint()) {
+      case NOP: {
+        mnemonic = "nop";
+        form = NULL;
+        break;
+      }
+    }
+  } else if (instr->Mask(MemBarrierFMask) == MemBarrierFixed) {
+    switch (instr->Mask(MemBarrierMask)) {
+      case DMB: {
+        mnemonic = "dmb";
+        form = "'M";
+        break;
+      }
+      case DSB: {
+        mnemonic = "dsb";
+        form = "'M";
+        break;
+      }
+      case ISB: {
+        mnemonic = "isb";
+        form = NULL;
+        break;
+      }
+    }
+  }
+
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitException(const Instruction* instr) {
+  const char *mnemonic = "unimplemented";
+  const char *form = "'IDebug";
+
+  switch (instr->Mask(ExceptionMask)) {
+    case HLT: mnemonic = "hlt"; break;
+    case BRK: mnemonic = "brk"; break;
+    case SVC: mnemonic = "svc"; break;
+    case HVC: mnemonic = "hvc"; break;
+    case SMC: mnemonic = "smc"; break;
+    case DCPS1: mnemonic = "dcps1"; form = "{'IDebug}"; break;
+    case DCPS2: mnemonic = "dcps2"; form = "{'IDebug}"; break;
+    case DCPS3: mnemonic = "dcps3"; form = "{'IDebug}"; break;
+    default: form = "(Exception)";
+  }
+  Format(instr, mnemonic, form);
+}
+
+
+void Disassembler::VisitUnimplemented(const Instruction* instr) {
+  Format(instr, "unimplemented", "(Unimplemented)");
+}
+
+
+void Disassembler::VisitUnallocated(const Instruction* instr) {
+  Format(instr, "unallocated", "(Unallocated)");
+}
+
+
+void Disassembler::ProcessOutput(const Instruction* /*instr*/) {
+  // The base disasm does nothing more than disassembling into a buffer.
+}
+
+
+void Disassembler::AppendRegisterNameToOutput(const Instruction* instr,
+                                              const CPURegister& reg) {
+  USE(instr);
+  VIXL_ASSERT(reg.IsValid());
+  char reg_char;
+
+  if (reg.IsRegister()) {
+    reg_char = reg.Is64Bits() ? 'x' : 'w';
+  } else {
+    VIXL_ASSERT(reg.IsFPRegister());
+    reg_char = reg.Is64Bits() ? 'd' : 's';
+  }
+
+  if (reg.IsFPRegister() || !(reg.Aliases(sp) || reg.Aliases(xzr))) {
+    // A normal register: w0 - w30, x0 - x30, s0 - s31, d0 - d31.
+    AppendToOutput("%c%d", reg_char, reg.code());
+  } else if (reg.Aliases(sp)) {
+    // Disassemble w31/x31 as stack pointer wsp/sp.
+    AppendToOutput("%s", reg.Is64Bits() ? "sp" : "wsp");
+  } else {
+    // Disassemble w31/x31 as zero register wzr/xzr.
+    AppendToOutput("%czr", reg_char);
+  }
+}
+
+
+void Disassembler::AppendPCRelativeOffsetToOutput(const Instruction* instr,
+                                                  int64_t offset) {
+  USE(instr);
+  char sign = (offset < 0) ? '-' : '+';
+  AppendToOutput("#%c0x%" PRIx64, sign, std::abs(offset));
+}
+
+
+void Disassembler::AppendAddressToOutput(const Instruction* instr,
+                                         const void* addr) {
+  USE(instr);
+  AppendToOutput("(addr 0x%" PRIxPTR ")", reinterpret_cast<uintptr_t>(addr));
+}
+
+
+void Disassembler::AppendCodeAddressToOutput(const Instruction* instr,
+                                             const void* addr) {
+  AppendAddressToOutput(instr, addr);
+}
+
+
+void Disassembler::AppendDataAddressToOutput(const Instruction* instr,
+                                             const void* addr) {
+  AppendAddressToOutput(instr, addr);
+}
+
+
+void Disassembler::AppendCodeRelativeAddressToOutput(const Instruction* instr,
+                                                     const void* addr) {
+  USE(instr);
+  int64_t rel_addr = CodeRelativeAddress(addr);
+  if (rel_addr >= 0) {
+    AppendToOutput("(addr 0x%" PRIx64 ")", rel_addr);
+  } else {
+    AppendToOutput("(addr -0x%" PRIx64 ")", -rel_addr);
+  }
+}
+
+
+void Disassembler::AppendCodeRelativeCodeAddressToOutput(
+    const Instruction* instr, const void* addr) {
+  AppendCodeRelativeAddressToOutput(instr, addr);
+}
+
+
+void Disassembler::AppendCodeRelativeDataAddressToOutput(
+    const Instruction* instr, const void* addr) {
+  AppendCodeRelativeAddressToOutput(instr, addr);
+}
+
+
+void Disassembler::MapCodeAddress(int64_t base_address,
+                                  const Instruction* instr_address) {
+  set_code_address_offset(
+      base_address - reinterpret_cast<intptr_t>(instr_address));
+}
+int64_t Disassembler::CodeRelativeAddress(const void* addr) {
+  return reinterpret_cast<intptr_t>(addr) + code_address_offset();
+}
+
+
+void Disassembler::Format(const Instruction* instr, const char* mnemonic,
+                          const char* format) {
+  VIXL_ASSERT(mnemonic != NULL);
+  ResetOutput();
+  Substitute(instr, mnemonic);
+  if (format != NULL) {
+    buffer_[buffer_pos_++] = ' ';
+    Substitute(instr, format);
+  }
+  buffer_[buffer_pos_] = 0;
+  ProcessOutput(instr);
+}
+
+
+void Disassembler::Substitute(const Instruction* instr, const char* string) {
+  char chr = *string++;
+  while (chr != '\0') {
+    if (chr == '\'') {
+      string += SubstituteField(instr, string);
+    } else {
+      buffer_[buffer_pos_++] = chr;
+    }
+    chr = *string++;
+  }
+}
+
+
+int Disassembler::SubstituteField(const Instruction* instr,
+                                  const char* format) {
+  switch (format[0]) {
+    case 'R':  // Register. X or W, selected by sf bit.
+    case 'F':  // FP Register. S or D, selected by type field.
+    case 'W':
+    case 'X':
+    case 'S':
+    case 'D': return SubstituteRegisterField(instr, format);
+    case 'I': return SubstituteImmediateField(instr, format);
+    case 'L': return SubstituteLiteralField(instr, format);
+    case 'H': return SubstituteShiftField(instr, format);
+    case 'P': return SubstitutePrefetchField(instr, format);
+    case 'C': return SubstituteConditionField(instr, format);
+    case 'E': return SubstituteExtendField(instr, format);
+    case 'A': return SubstitutePCRelAddressField(instr, format);
+    case 'B': return SubstituteBranchTargetField(instr, format);
+    case 'O': return SubstituteLSRegOffsetField(instr, format);
+    case 'M': return SubstituteBarrierField(instr, format);
+    default: {
+      VIXL_UNREACHABLE();
+      return 1;
+    }
+  }
+}
+
+
+int Disassembler::SubstituteRegisterField(const Instruction* instr,
+                                          const char* format) {
+  unsigned reg_num = 0;
+  unsigned field_len = 2;
+  switch (format[1]) {
+    case 'd': reg_num = instr->Rd(); break;
+    case 'n': reg_num = instr->Rn(); break;
+    case 'm': reg_num = instr->Rm(); break;
+    case 'a': reg_num = instr->Ra(); break;
+    case 's': reg_num = instr->Rs(); break;
+    case 't': {
+      if (format[2] == '2') {
+        reg_num = instr->Rt2();
+        field_len = 3;
+      } else {
+        reg_num = instr->Rt();
+      }
+      break;
+    }
+    default: VIXL_UNREACHABLE();
+  }
+
+  // Increase field length for registers tagged as stack.
+  if (format[2] == 's') {
+    field_len = 3;
+  }
+
+  CPURegister::RegisterType reg_type;
+  unsigned reg_size;
+
+  if (format[0] == 'R') {
+    // Register type is R: use sf bit to choose X and W.
+    reg_type = CPURegister::kRegister;
+    reg_size = instr->SixtyFourBits() ? kXRegSize : kWRegSize;
+  } else if (format[0] == 'F') {
+    // Floating-point register: use type field to choose S or D.
+    reg_type = CPURegister::kFPRegister;
+    reg_size = ((instr->FPType() & 1) == 0) ? kSRegSize : kDRegSize;
+  } else {
+    // The register type is specified.
+    switch (format[0]) {
+      case 'W':
+        reg_type = CPURegister::kRegister; reg_size = kWRegSize; break;
+      case 'X':
+        reg_type = CPURegister::kRegister; reg_size = kXRegSize; break;
+      case 'S':
+        reg_type = CPURegister::kFPRegister; reg_size = kSRegSize; break;
+      case 'D':
+        reg_type = CPURegister::kFPRegister; reg_size = kDRegSize; break;
+      default:
+        VIXL_UNREACHABLE();
+        reg_type = CPURegister::kRegister;
+        reg_size = kXRegSize;
+    }
+  }
+
+  if ((reg_type == CPURegister::kRegister) &&
+      (reg_num == kZeroRegCode) && (format[2] == 's')) {
+    reg_num = kSPRegInternalCode;
+  }
+
+  AppendRegisterNameToOutput(instr, CPURegister(reg_num, reg_size, reg_type));
+
+  return field_len;
+}
+
+
+int Disassembler::SubstituteImmediateField(const Instruction* instr,
+                                           const char* format) {
+  VIXL_ASSERT(format[0] == 'I');
+
+  switch (format[1]) {
+    case 'M': {  // IMoveImm, IMoveNeg or IMoveLSL.
+      if (format[5] == 'L') {
+        AppendToOutput("#0x%" PRIx64, instr->ImmMoveWide());
+        if (instr->ShiftMoveWide() > 0) {
+          AppendToOutput(", lsl #%" PRId64, 16 * instr->ShiftMoveWide());
+        }
+      } else {
+        VIXL_ASSERT((format[5] == 'I') || (format[5] == 'N'));
+        uint64_t imm = instr->ImmMoveWide() << (16 * instr->ShiftMoveWide());
+        if (format[5] == 'N')
+          imm = ~imm;
+        if (!instr->SixtyFourBits())
+          imm &= UINT64_C(0xffffffff);
+        AppendToOutput("#0x%" PRIx64, imm);
+      }
+      return 8;
+    }
+    case 'L': {
+      switch (format[2]) {
+        case 'L': {  // ILLiteral - Immediate Load Literal.
+          AppendToOutput("pc%+" PRId64,
+                         instr->ImmLLiteral() << kLiteralEntrySizeLog2);
+          return 9;
+        }
+        case 'S': {  // ILS - Immediate Load/Store.
+          if (instr->ImmLS() != 0) {
+            AppendToOutput(", #%" PRId64, instr->ImmLS());
+          }
+          return 3;
+        }
+        case 'P': {  // ILPx - Immediate Load/Store Pair, x = access size.
+          if (instr->ImmLSPair() != 0) {
+            // format[3] is the scale value. Convert to a number.
+            int scale = format[3] - 0x30;
+            AppendToOutput(", #%" PRId64, instr->ImmLSPair() * scale);
+          }
+          return 4;
+        }
+        case 'U': {  // ILU - Immediate Load/Store Unsigned.
+          if (instr->ImmLSUnsigned() != 0) {
+            AppendToOutput(", #%" PRIu64,
+                           instr->ImmLSUnsigned() << instr->SizeLS());
+          }
+          return 3;
+        }
+      }
+    }
+    case 'C': {  // ICondB - Immediate Conditional Branch.
+      int64_t offset = instr->ImmCondBranch() << 2;
+      AppendPCRelativeOffsetToOutput(instr, offset);
+      return 6;
+    }
+    case 'A': {  // IAddSub.
+      VIXL_ASSERT(instr->ShiftAddSub() <= 1);
+      int64_t imm = instr->ImmAddSub() << (12 * instr->ShiftAddSub());
+      AppendToOutput("#0x%" PRIx64 " (%" PRId64 ")", imm, imm);
+      return 7;
+    }
+    case 'F': {  // IFPSingle, IFPDouble or IFPFBits.
+      if (format[3] == 'F') {  // IFPFbits.
+        AppendToOutput("#%" PRId64, 64 - instr->FPScale());
+        return 8;
+      } else {
+        AppendToOutput("#0x%" PRIx64 " (%.4f)", instr->ImmFP(),
+                       format[3] == 'S' ? instr->ImmFP32() : instr->ImmFP64());
+        return 9;
+      }
+    }
+    case 'T': {  // ITri - Immediate Triangular Encoded.
+      AppendToOutput("#0x%" PRIx64, instr->ImmLogical());
+      return 4;
+    }
+    case 'N': {  // INzcv.
+      int nzcv = (instr->Nzcv() << Flags_offset);
+      AppendToOutput("#%c%c%c%c", ((nzcv & NFlag) == 0) ? 'n' : 'N',
+                                  ((nzcv & ZFlag) == 0) ? 'z' : 'Z',
+                                  ((nzcv & CFlag) == 0) ? 'c' : 'C',
+                                  ((nzcv & VFlag) == 0) ? 'v' : 'V');
+      return 5;
+    }
+    case 'P': {  // IP - Conditional compare.
+      AppendToOutput("#%" PRId64, instr->ImmCondCmp());
+      return 2;
+    }
+    case 'B': {  // Bitfields.
+      return SubstituteBitfieldImmediateField(instr, format);
+    }
+    case 'E': {  // IExtract.
+      AppendToOutput("#%" PRId64, instr->ImmS());
+      return 8;
+    }
+    case 'S': {  // IS - Test and branch bit.
+      AppendToOutput("#%" PRId64, (instr->ImmTestBranchBit5() << 5) |
+                                  instr->ImmTestBranchBit40());
+      return 2;
+    }
+    case 'D': {  // IDebug - HLT and BRK instructions.
+      AppendToOutput("#0x%" PRIx64, instr->ImmException());
+      return 6;
+    }
+    case 'X': {  // IX - CLREX instruction.
+      AppendToOutput("#0x%" PRIx64, instr->CRm());
+      return 2;
+    }
+    default: {
+      VIXL_UNIMPLEMENTED();
+      return 0;
+    }
+  }
+}
+
+
+int Disassembler::SubstituteBitfieldImmediateField(const Instruction* instr,
+                                                   const char* format) {
+  VIXL_ASSERT((format[0] == 'I') && (format[1] == 'B'));
+  unsigned r = instr->ImmR();
+  unsigned s = instr->ImmS();
+
+  switch (format[2]) {
+    case 'r': {  // IBr.
+      AppendToOutput("#%d", r);
+      return 3;
+    }
+    case 's': {  // IBs+1 or IBs-r+1.
+      if (format[3] == '+') {
+        AppendToOutput("#%d", s + 1);
+        return 5;
+      } else {
+        VIXL_ASSERT(format[3] == '-');
+        AppendToOutput("#%d", s - r + 1);
+        return 7;
+      }
+    }
+    case 'Z': {  // IBZ-r.
+      VIXL_ASSERT((format[3] == '-') && (format[4] == 'r'));
+      unsigned reg_size = (instr->SixtyFourBits() == 1) ? kXRegSize : kWRegSize;
+      AppendToOutput("#%d", reg_size - r);
+      return 5;
+    }
+    default: {
+      VIXL_UNREACHABLE();
+      return 0;
+    }
+  }
+}
+
+
+int Disassembler::SubstituteLiteralField(const Instruction* instr,
+                                         const char* format) {
+  VIXL_ASSERT(strncmp(format, "LValue", 6) == 0);
+  USE(format);
+
+  const void * address = instr->LiteralAddress<const void *>();
+  switch (instr->Mask(LoadLiteralMask)) {
+    case LDR_w_lit:
+    case LDR_x_lit:
+    case LDRSW_x_lit:
+    case LDR_s_lit:
+    case LDR_d_lit:
+      AppendCodeRelativeDataAddressToOutput(instr, address);
+      break;
+    case PRFM_lit: {
+      // Use the prefetch hint to decide how to print the address.
+      switch (instr->PrefetchHint()) {
+        case 0x0:     // PLD: prefetch for load.
+        case 0x2:     // PST: prepare for store.
+          AppendCodeRelativeDataAddressToOutput(instr, address);
+          break;
+        case 0x1:     // PLI: preload instructions.
+          AppendCodeRelativeCodeAddressToOutput(instr, address);
+          break;
+        case 0x3:     // Unallocated hint.
+          AppendCodeRelativeAddressToOutput(instr, address);
+          break;
+      }
+      break;
+    }
+    default:
+      VIXL_UNREACHABLE();
+  }
+
+  return 6;
+}
+
+
+int Disassembler::SubstituteShiftField(const Instruction* instr,
+                                       const char* format) {
+  VIXL_ASSERT(format[0] == 'H');
+  VIXL_ASSERT(instr->ShiftDP() <= 0x3);
+
+  switch (format[1]) {
+    case 'D': {  // HDP.
+      VIXL_ASSERT(instr->ShiftDP() != ROR);
+    }  // Fall through.
+    case 'L': {  // HLo.
+      if (instr->ImmDPShift() != 0) {
+        const char* shift_type[] = {"lsl", "lsr", "asr", "ror"};
+        AppendToOutput(", %s #%" PRId64, shift_type[instr->ShiftDP()],
+                       instr->ImmDPShift());
+      }
+      return 3;
+    }
+    default:
+      VIXL_UNIMPLEMENTED();
+      return 0;
+  }
+}
+
+
+int Disassembler::SubstituteConditionField(const Instruction* instr,
+                                           const char* format) {
+  VIXL_ASSERT(format[0] == 'C');
+  const char* condition_code[] = { "eq", "ne", "hs", "lo",
+                                   "mi", "pl", "vs", "vc",
+                                   "hi", "ls", "ge", "lt",
+                                   "gt", "le", "al", "nv" };
+  int cond;
+  switch (format[1]) {
+    case 'B': cond = instr->ConditionBranch(); break;
+    case 'I': {
+      cond = InvertCondition(static_cast<Condition>(instr->Condition()));
+      break;
+    }
+    default: cond = instr->Condition();
+  }
+  AppendToOutput("%s", condition_code[cond]);
+  return 4;
+}
+
+
+int Disassembler::SubstitutePCRelAddressField(const Instruction* instr,
+                                              const char* format) {
+  VIXL_ASSERT((strcmp(format, "AddrPCRelByte") == 0) ||   // Used by `adr`.
+              (strcmp(format, "AddrPCRelPage") == 0));    // Used by `adrp`.
+
+  int64_t offset = instr->ImmPCRel();
+
+  // Compute the target address based on the effective address (after applying
+  // code_address_offset). This is required for correct behaviour of adrp.
+  const Instruction* base = instr + code_address_offset();
+  if (format[9] == 'P') {
+    offset *= kPageSize;
+    base = AlignDown(base, kPageSize);
+  }
+  // Strip code_address_offset before printing, so we can use the
+  // semantically-correct AppendCodeRelativeAddressToOutput.
+  const void* target =
+      reinterpret_cast<const void*>(base + offset - code_address_offset());
+
+  AppendPCRelativeOffsetToOutput(instr, offset);
+  AppendToOutput(" ");
+  AppendCodeRelativeAddressToOutput(instr, target);
+  return 13;
+}
+
+
+int Disassembler::SubstituteBranchTargetField(const Instruction* instr,
+                                              const char* format) {
+  VIXL_ASSERT(strncmp(format, "BImm", 4) == 0);
+
+  int64_t offset = 0;
+  switch (format[5]) {
+    // BImmUncn - unconditional branch immediate.
+    case 'n': offset = instr->ImmUncondBranch(); break;
+    // BImmCond - conditional branch immediate.
+    case 'o': offset = instr->ImmCondBranch(); break;
+    // BImmCmpa - compare and branch immediate.
+    case 'm': offset = instr->ImmCmpBranch(); break;
+    // BImmTest - test and branch immediate.
+    case 'e': offset = instr->ImmTestBranch(); break;
+    default: VIXL_UNIMPLEMENTED();
+  }
+  offset <<= kInstructionSizeLog2;
+  const void* target_address = reinterpret_cast<const void*>(instr + offset);
+  VIXL_STATIC_ASSERT(sizeof(*instr) == 1);
+
+  AppendPCRelativeOffsetToOutput(instr, offset);
+  AppendToOutput(" ");
+  AppendCodeRelativeCodeAddressToOutput(instr, target_address);
+
+  return 8;
+}
+
+
+int Disassembler::SubstituteExtendField(const Instruction* instr,
+                                        const char* format) {
+  VIXL_ASSERT(strncmp(format, "Ext", 3) == 0);
+  VIXL_ASSERT(instr->ExtendMode() <= 7);
+  USE(format);
+
+  const char* extend_mode[] = { "uxtb", "uxth", "uxtw", "uxtx",
+                                "sxtb", "sxth", "sxtw", "sxtx" };
+
+  // If rd or rn is SP, uxtw on 32-bit registers and uxtx on 64-bit
+  // registers becomes lsl.
+  if (((instr->Rd() == kZeroRegCode) || (instr->Rn() == kZeroRegCode)) &&
+      (((instr->ExtendMode() == UXTW) && (instr->SixtyFourBits() == 0)) ||
+       (instr->ExtendMode() == UXTX))) {
+    if (instr->ImmExtendShift() > 0) {
+      AppendToOutput(", lsl #%" PRId64, instr->ImmExtendShift());
+    }
+  } else {
+    AppendToOutput(", %s", extend_mode[instr->ExtendMode()]);
+    if (instr->ImmExtendShift() > 0) {
+      AppendToOutput(" #%" PRId64, instr->ImmExtendShift());
+    }
+  }
+  return 3;
+}
+
+
+int Disassembler::SubstituteLSRegOffsetField(const Instruction* instr,
+                                             const char* format) {
+  VIXL_ASSERT(strncmp(format, "Offsetreg", 9) == 0);
+  const char* extend_mode[] = { "undefined", "undefined", "uxtw", "lsl",
+                                "undefined", "undefined", "sxtw", "sxtx" };
+  USE(format);
+
+  unsigned shift = instr->ImmShiftLS();
+  Extend ext = static_cast<Extend>(instr->ExtendMode());
+  char reg_type = ((ext == UXTW) || (ext == SXTW)) ? 'w' : 'x';
+
+  unsigned rm = instr->Rm();
+  if (rm == kZeroRegCode) {
+    AppendToOutput("%czr", reg_type);
+  } else {
+    AppendToOutput("%c%d", reg_type, rm);
+  }
+
+  // Extend mode UXTX is an alias for shift mode LSL here.
+  if (!((ext == UXTX) && (shift == 0))) {
+    AppendToOutput(", %s", extend_mode[ext]);
+    if (shift != 0) {
+      AppendToOutput(" #%" PRId64, instr->SizeLS());
+    }
+  }
+  return 9;
+}
+
+
+int Disassembler::SubstitutePrefetchField(const Instruction* instr,
+                                          const char* format) {
+  VIXL_ASSERT(format[0] == 'P');
+  USE(format);
+
+  static const char* hints[] = {"ld", "li", "st"};
+  static const char* stream_options[] = {"keep", "strm"};
+
+  unsigned hint = instr->PrefetchHint();
+  unsigned target = instr->PrefetchTarget() + 1;
+  unsigned stream = instr->PrefetchStream();
+
+  if ((hint >= (sizeof(hints) / sizeof(hints[0]))) || (target > 3)) {
+    // Unallocated prefetch operations.
+    int prefetch_mode = instr->ImmPrefetchOperation();
+    AppendToOutput("#0b%c%c%c%c%c",
+                   (prefetch_mode & (1 << 4)) ? '1' : '0',
+                   (prefetch_mode & (1 << 3)) ? '1' : '0',
+                   (prefetch_mode & (1 << 2)) ? '1' : '0',
+                   (prefetch_mode & (1 << 1)) ? '1' : '0',
+                   (prefetch_mode & (1 << 0)) ? '1' : '0');
+  } else {
+    VIXL_ASSERT(stream < (sizeof(stream_options) / sizeof(stream_options[0])));
+    AppendToOutput("p%sl%d%s", hints[hint], target, stream_options[stream]);
+  }
+  return 6;
+}
+
+int Disassembler::SubstituteBarrierField(const Instruction* instr,
+                                         const char* format) {
+  VIXL_ASSERT(format[0] == 'M');
+  USE(format);
+
+  static const char* options[4][4] = {
+    { "sy (0b0000)", "oshld", "oshst", "osh" },
+    { "sy (0b0100)", "nshld", "nshst", "nsh" },
+    { "sy (0b1000)", "ishld", "ishst", "ish" },
+    { "sy (0b1100)", "ld", "st", "sy" }
+  };
+  int domain = instr->ImmBarrierDomain();
+  int type = instr->ImmBarrierType();
+
+  AppendToOutput("%s", options[domain][type]);
+  return 1;
+}
+
+void Disassembler::ResetOutput() {
+  buffer_pos_ = 0;
+  buffer_[buffer_pos_] = 0;
+}
+
+
+void Disassembler::AppendToOutput(const char* format, ...) {
+  va_list args;
+  va_start(args, format);
+  buffer_pos_ += vsnprintf(&buffer_[buffer_pos_], buffer_size_, format, args);
+  va_end(args);
+}
+
+
+void PrintDisassembler::ProcessOutput(const Instruction* instr) {
+  fprintf(stream_, "0x%016" PRIx64 "  %08" PRIx32 "\t\t%s\n",
+          reinterpret_cast<uint64_t>(instr),
+          instr->InstructionBits(),
+          GetOutput());
+}
+}  // namespace vixl
diff --git a/qemu/disas/libvixl/a64/disasm-a64.h b/qemu/disas/libvixl/a64/disasm-a64.h
new file mode 100644
index 000000000..ddfe98be1
--- /dev/null
+++ b/qemu/disas/libvixl/a64/disasm-a64.h
@@ -0,0 +1,176 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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 VIXL_A64_DISASM_A64_H
+#define VIXL_A64_DISASM_A64_H
+
+#include "globals.h"
+#include "utils.h"
+#include "instructions-a64.h"
+#include "decoder-a64.h"
+#include "assembler-a64.h"
+
+namespace vixl {
+
+class Disassembler: public DecoderVisitor {
+ public:
+  Disassembler();
+  Disassembler(char* text_buffer, int buffer_size);
+  virtual ~Disassembler();
+  char* GetOutput();
+
+  // Declare all Visitor functions.
+  #define DECLARE(A) virtual void Visit##A(const Instruction* instr);
+  VISITOR_LIST(DECLARE)
+  #undef DECLARE
+
+ protected:
+  virtual void ProcessOutput(const Instruction* instr);
+
+  // Default output functions.  The functions below implement a default way of
+  // printing elements in the disassembly. A sub-class can override these to
+  // customize the disassembly output.
+
+  // Prints the name of a register.
+  virtual void AppendRegisterNameToOutput(const Instruction* instr,
+                                          const CPURegister& reg);
+
+  // Prints a PC-relative offset. This is used for example when disassembling
+  // branches to immediate offsets.
+  virtual void AppendPCRelativeOffsetToOutput(const Instruction* instr,
+                                              int64_t offset);
+
+  // Prints an address, in the general case. It can be code or data. This is
+  // used for example to print the target address of an ADR instruction.
+  virtual void AppendCodeRelativeAddressToOutput(const Instruction* instr,
+                                                 const void* addr);
+
+  // Prints the address of some code.
+  // This is used for example to print the target address of a branch to an
+  // immediate offset.
+  // A sub-class can for example override this method to lookup the address and
+  // print an appropriate name.
+  virtual void AppendCodeRelativeCodeAddressToOutput(const Instruction* instr,
+                                                     const void* addr);
+
+  // Prints the address of some data.
+  // This is used for example to print the source address of a load literal
+  // instruction.
+  virtual void AppendCodeRelativeDataAddressToOutput(const Instruction* instr,
+                                                     const void* addr);
+
+  // Same as the above, but for addresses that are not relative to the code
+  // buffer. They are currently not used by VIXL.
+  virtual void AppendAddressToOutput(const Instruction* instr,
+                                     const void* addr);
+  virtual void AppendCodeAddressToOutput(const Instruction* instr,
+                                         const void* addr);
+  virtual void AppendDataAddressToOutput(const Instruction* instr,
+                                         const void* addr);
+
+ public:
+  // Get/Set the offset that should be added to code addresses when printing
+  // code-relative addresses in the AppendCodeRelative<Type>AddressToOutput()
+  // helpers.
+  // Below is an example of how a branch immediate instruction in memory at
+  // address 0xb010200 would disassemble with different offsets.
+  // Base address | Disassembly
+  //          0x0 | 0xb010200:  b #+0xcc  (addr 0xb0102cc)
+  //      0x10000 | 0xb000200:  b #+0xcc  (addr 0xb0002cc)
+  //    0xb010200 |       0x0:  b #+0xcc  (addr 0xcc)
+  void MapCodeAddress(int64_t base_address, const Instruction* instr_address);
+  int64_t CodeRelativeAddress(const void* instr);
+
+ private:
+  void Format(
+      const Instruction* instr, const char* mnemonic, const char* format);
+  void Substitute(const Instruction* instr, const char* string);
+  int SubstituteField(const Instruction* instr, const char* format);
+  int SubstituteRegisterField(const Instruction* instr, const char* format);
+  int SubstituteImmediateField(const Instruction* instr, const char* format);
+  int SubstituteLiteralField(const Instruction* instr, const char* format);
+  int SubstituteBitfieldImmediateField(
+      const Instruction* instr, const char* format);
+  int SubstituteShiftField(const Instruction* instr, const char* format);
+  int SubstituteExtendField(const Instruction* instr, const char* format);
+  int SubstituteConditionField(const Instruction* instr, const char* format);
+  int SubstitutePCRelAddressField(const Instruction* instr, const char* format);
+  int SubstituteBranchTargetField(const Instruction* instr, const char* format);
+  int SubstituteLSRegOffsetField(const Instruction* instr, const char* format);
+  int SubstitutePrefetchField(const Instruction* instr, const char* format);
+  int SubstituteBarrierField(const Instruction* instr, const char* format);
+
+  bool RdIsZROrSP(const Instruction* instr) const {
+    return (instr->Rd() == kZeroRegCode);
+  }
+
+  bool RnIsZROrSP(const Instruction* instr) const {
+    return (instr->Rn() == kZeroRegCode);
+  }
+
+  bool RmIsZROrSP(const Instruction* instr) const {
+    return (instr->Rm() == kZeroRegCode);
+  }
+
+  bool RaIsZROrSP(const Instruction* instr) const {
+    return (instr->Ra() == kZeroRegCode);
+  }
+
+  bool IsMovzMovnImm(unsigned reg_size, uint64_t value);
+
+  int64_t code_address_offset() const { return code_address_offset_; }
+
+ protected:
+  void ResetOutput();
+  void AppendToOutput(const char* string, ...) PRINTF_CHECK(2, 3);
+
+  void set_code_address_offset(int64_t code_address_offset) {
+    code_address_offset_ = code_address_offset;
+  }
+
+  char* buffer_;
+  uint32_t buffer_pos_;
+  uint32_t buffer_size_;
+  bool own_buffer_;
+
+  int64_t code_address_offset_;
+};
+
+
+class PrintDisassembler: public Disassembler {
+ public:
+  explicit PrintDisassembler(FILE* stream) : stream_(stream) { }
+  virtual ~PrintDisassembler() { }
+
+ protected:
+  virtual void ProcessOutput(const Instruction* instr);
+
+ private:
+  FILE *stream_;
+};
+}  // namespace vixl
+
+#endif  // VIXL_A64_DISASM_A64_H
diff --git a/qemu/disas/libvixl/a64/instructions-a64.cc b/qemu/disas/libvixl/a64/instructions-a64.cc
new file mode 100644
index 000000000..b09188683
--- /dev/null
+++ b/qemu/disas/libvixl/a64/instructions-a64.cc
@@ -0,0 +1,314 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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.
+
+#include "a64/instructions-a64.h"
+#include "a64/assembler-a64.h"
+
+namespace vixl {
+
+
+// Floating-point infinity values.
+const float kFP32PositiveInfinity = rawbits_to_float(0x7f800000);
+const float kFP32NegativeInfinity = rawbits_to_float(0xff800000);
+const double kFP64PositiveInfinity =
+    rawbits_to_double(UINT64_C(0x7ff0000000000000));
+const double kFP64NegativeInfinity =
+    rawbits_to_double(UINT64_C(0xfff0000000000000));
+
+
+// The default NaN values (for FPCR.DN=1).
+const double kFP64DefaultNaN = rawbits_to_double(UINT64_C(0x7ff8000000000000));
+const float kFP32DefaultNaN = rawbits_to_float(0x7fc00000);
+
+
+static uint64_t RotateRight(uint64_t value,
+                            unsigned int rotate,
+                            unsigned int width) {
+  VIXL_ASSERT(width <= 64);
+  rotate &= 63;
+  return ((value & ((UINT64_C(1) << rotate) - 1)) <<
+          (width - rotate)) | (value >> rotate);
+}
+
+
+static uint64_t RepeatBitsAcrossReg(unsigned reg_size,
+                                    uint64_t value,
+                                    unsigned width) {
+  VIXL_ASSERT((width == 2) || (width == 4) || (width == 8) || (width == 16) ||
+              (width == 32));
+  VIXL_ASSERT((reg_size == kWRegSize) || (reg_size == kXRegSize));
+  uint64_t result = value & ((UINT64_C(1) << width) - 1);
+  for (unsigned i = width; i < reg_size; i *= 2) {
+    result |= (result << i);
+  }
+  return result;
+}
+
+
+bool Instruction::IsLoad() const {
+  if (Mask(LoadStoreAnyFMask) != LoadStoreAnyFixed) {
+    return false;
+  }
+
+  if (Mask(LoadStorePairAnyFMask) == LoadStorePairAnyFixed) {
+    return Mask(LoadStorePairLBit) != 0;
+  } else {
+    LoadStoreOp op = static_cast<LoadStoreOp>(Mask(LoadStoreOpMask));
+    switch (op) {
+      case LDRB_w:
+      case LDRH_w:
+      case LDR_w:
+      case LDR_x:
+      case LDRSB_w:
+      case LDRSB_x:
+      case LDRSH_w:
+      case LDRSH_x:
+      case LDRSW_x:
+      case LDR_s:
+      case LDR_d: return true;
+      default: return false;
+    }
+  }
+}
+
+
+bool Instruction::IsStore() const {
+  if (Mask(LoadStoreAnyFMask) != LoadStoreAnyFixed) {
+    return false;
+  }
+
+  if (Mask(LoadStorePairAnyFMask) == LoadStorePairAnyFixed) {
+    return Mask(LoadStorePairLBit) == 0;
+  } else {
+    LoadStoreOp op = static_cast<LoadStoreOp>(Mask(LoadStoreOpMask));
+    switch (op) {
+      case STRB_w:
+      case STRH_w:
+      case STR_w:
+      case STR_x:
+      case STR_s:
+      case STR_d: return true;
+      default: return false;
+    }
+  }
+}
+
+
+// Logical immediates can't encode zero, so a return value of zero is used to
+// indicate a failure case. Specifically, where the constraints on imm_s are
+// not met.
+uint64_t Instruction::ImmLogical() const {
+  unsigned reg_size = SixtyFourBits() ? kXRegSize : kWRegSize;
+  int64_t n = BitN();
+  int64_t imm_s = ImmSetBits();
+  int64_t imm_r = ImmRotate();
+
+  // An integer is constructed from the n, imm_s and imm_r bits according to
+  // the following table:
+  //
+  //  N   imms    immr    size        S             R
+  //  1  ssssss  rrrrrr    64    UInt(ssssss)  UInt(rrrrrr)
+  //  0  0sssss  xrrrrr    32    UInt(sssss)   UInt(rrrrr)
+  //  0  10ssss  xxrrrr    16    UInt(ssss)    UInt(rrrr)
+  //  0  110sss  xxxrrr     8    UInt(sss)     UInt(rrr)
+  //  0  1110ss  xxxxrr     4    UInt(ss)      UInt(rr)
+  //  0  11110s  xxxxxr     2    UInt(s)       UInt(r)
+  // (s bits must not be all set)
+  //
+  // A pattern is constructed of size bits, where the least significant S+1
+  // bits are set. The pattern is rotated right by R, and repeated across a
+  // 32 or 64-bit value, depending on destination register width.
+  //
+
+  if (n == 1) {
+    if (imm_s == 0x3F) {
+      return 0;
+    }
+    uint64_t bits = (UINT64_C(1) << (imm_s + 1)) - 1;
+    return RotateRight(bits, imm_r, 64);
+  } else {
+    if ((imm_s >> 1) == 0x1F) {
+      return 0;
+    }
+    for (int width = 0x20; width >= 0x2; width >>= 1) {
+      if ((imm_s & width) == 0) {
+        int mask = width - 1;
+        if ((imm_s & mask) == mask) {
+          return 0;
+        }
+        uint64_t bits = (UINT64_C(1) << ((imm_s & mask) + 1)) - 1;
+        return RepeatBitsAcrossReg(reg_size,
+                                   RotateRight(bits, imm_r & mask, width),
+                                   width);
+      }
+    }
+  }
+  VIXL_UNREACHABLE();
+  return 0;
+}
+
+
+float Instruction::ImmFP32() const {
+  //  ImmFP: abcdefgh (8 bits)
+  // Single: aBbb.bbbc.defg.h000.0000.0000.0000.0000 (32 bits)
+  // where B is b ^ 1
+  uint32_t bits = ImmFP();
+  uint32_t bit7 = (bits >> 7) & 0x1;
+  uint32_t bit6 = (bits >> 6) & 0x1;
+  uint32_t bit5_to_0 = bits & 0x3f;
+  uint32_t result = (bit7 << 31) | ((32 - bit6) << 25) | (bit5_to_0 << 19);
+
+  return rawbits_to_float(result);
+}
+
+
+double Instruction::ImmFP64() const {
+  //  ImmFP: abcdefgh (8 bits)
+  // Double: aBbb.bbbb.bbcd.efgh.0000.0000.0000.0000
+  //         0000.0000.0000.0000.0000.0000.0000.0000 (64 bits)
+  // where B is b ^ 1
+  uint32_t bits = ImmFP();
+  uint64_t bit7 = (bits >> 7) & 0x1;
+  uint64_t bit6 = (bits >> 6) & 0x1;
+  uint64_t bit5_to_0 = bits & 0x3f;
+  uint64_t result = (bit7 << 63) | ((256 - bit6) << 54) | (bit5_to_0 << 48);
+
+  return rawbits_to_double(result);
+}
+
+
+LSDataSize CalcLSPairDataSize(LoadStorePairOp op) {
+  switch (op) {
+    case STP_x:
+    case LDP_x:
+    case STP_d:
+    case LDP_d: return LSDoubleWord;
+    default: return LSWord;
+  }
+}
+
+
+const Instruction* Instruction::ImmPCOffsetTarget() const {
+  const Instruction * base = this;
+  ptrdiff_t offset;
+  if (IsPCRelAddressing()) {
+    // ADR and ADRP.
+    offset = ImmPCRel();
+    if (Mask(PCRelAddressingMask) == ADRP) {
+      base = AlignDown(base, kPageSize);
+      offset *= kPageSize;
+    } else {
+      VIXL_ASSERT(Mask(PCRelAddressingMask) == ADR);
+    }
+  } else {
+    // All PC-relative branches.
+    VIXL_ASSERT(BranchType() != UnknownBranchType);
+    // Relative branch offsets are instruction-size-aligned.
+    offset = ImmBranch() << kInstructionSizeLog2;
+  }
+  return base + offset;
+}
+
+
+inline int Instruction::ImmBranch() const {
+  switch (BranchType()) {
+    case CondBranchType: return ImmCondBranch();
+    case UncondBranchType: return ImmUncondBranch();
+    case CompareBranchType: return ImmCmpBranch();
+    case TestBranchType: return ImmTestBranch();
+    default: VIXL_UNREACHABLE();
+  }
+  return 0;
+}
+
+
+void Instruction::SetImmPCOffsetTarget(const Instruction* target) {
+  if (IsPCRelAddressing()) {
+    SetPCRelImmTarget(target);
+  } else {
+    SetBranchImmTarget(target);
+  }
+}
+
+
+void Instruction::SetPCRelImmTarget(const Instruction* target) {
+  int32_t imm21;
+  if ((Mask(PCRelAddressingMask) == ADR)) {
+    imm21 = target - this;
+  } else {
+    VIXL_ASSERT(Mask(PCRelAddressingMask) == ADRP);
+    uintptr_t this_page = reinterpret_cast<uintptr_t>(this) / kPageSize;
+    uintptr_t target_page = reinterpret_cast<uintptr_t>(target) / kPageSize;
+    imm21 = target_page - this_page;
+  }
+  Instr imm = Assembler::ImmPCRelAddress(imm21);
+
+  SetInstructionBits(Mask(~ImmPCRel_mask) | imm);
+}
+
+
+void Instruction::SetBranchImmTarget(const Instruction* target) {
+  VIXL_ASSERT(((target - this) & 3) == 0);
+  Instr branch_imm = 0;
+  uint32_t imm_mask = 0;
+  int offset = (target - this) >> kInstructionSizeLog2;
+  switch (BranchType()) {
+    case CondBranchType: {
+      branch_imm = Assembler::ImmCondBranch(offset);
+      imm_mask = ImmCondBranch_mask;
+      break;
+    }
+    case UncondBranchType: {
+      branch_imm = Assembler::ImmUncondBranch(offset);
+      imm_mask = ImmUncondBranch_mask;
+      break;
+    }
+    case CompareBranchType: {
+      branch_imm = Assembler::ImmCmpBranch(offset);
+      imm_mask = ImmCmpBranch_mask;
+      break;
+    }
+    case TestBranchType: {
+      branch_imm = Assembler::ImmTestBranch(offset);
+      imm_mask = ImmTestBranch_mask;
+      break;
+    }
+    default: VIXL_UNREACHABLE();
+  }
+  SetInstructionBits(Mask(~imm_mask) | branch_imm);
+}
+
+
+void Instruction::SetImmLLiteral(const Instruction* source) {
+  VIXL_ASSERT(IsWordAligned(source));
+  ptrdiff_t offset = (source - this) >> kLiteralEntrySizeLog2;
+  Instr imm = Assembler::ImmLLiteral(offset);
+  Instr mask = ImmLLiteral_mask;
+
+  SetInstructionBits(Mask(~mask) | imm);
+}
+}  // namespace vixl
+
diff --git a/qemu/disas/libvixl/a64/instructions-a64.h b/qemu/disas/libvixl/a64/instructions-a64.h
new file mode 100644
index 000000000..f1d883ccc
--- /dev/null
+++ b/qemu/disas/libvixl/a64/instructions-a64.h
@@ -0,0 +1,384 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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 VIXL_A64_INSTRUCTIONS_A64_H_
+#define VIXL_A64_INSTRUCTIONS_A64_H_
+
+#include "globals.h"
+#include "utils.h"
+#include "a64/constants-a64.h"
+
+namespace vixl {
+// ISA constants. --------------------------------------------------------------
+
+typedef uint32_t Instr;
+const unsigned kInstructionSize = 4;
+const unsigned kInstructionSizeLog2 = 2;
+const unsigned kLiteralEntrySize = 4;
+const unsigned kLiteralEntrySizeLog2 = 2;
+const unsigned kMaxLoadLiteralRange = 1 * MBytes;
+
+// This is the nominal page size (as used by the adrp instruction); the actual
+// size of the memory pages allocated by the kernel is likely to differ.
+const unsigned kPageSize = 4 * KBytes;
+const unsigned kPageSizeLog2 = 12;
+
+const unsigned kWRegSize = 32;
+const unsigned kWRegSizeLog2 = 5;
+const unsigned kWRegSizeInBytes = kWRegSize / 8;
+const unsigned kWRegSizeInBytesLog2 = kWRegSizeLog2 - 3;
+const unsigned kXRegSize = 64;
+const unsigned kXRegSizeLog2 = 6;
+const unsigned kXRegSizeInBytes = kXRegSize / 8;
+const unsigned kXRegSizeInBytesLog2 = kXRegSizeLog2 - 3;
+const unsigned kSRegSize = 32;
+const unsigned kSRegSizeLog2 = 5;
+const unsigned kSRegSizeInBytes = kSRegSize / 8;
+const unsigned kSRegSizeInBytesLog2 = kSRegSizeLog2 - 3;
+const unsigned kDRegSize = 64;
+const unsigned kDRegSizeLog2 = 6;
+const unsigned kDRegSizeInBytes = kDRegSize / 8;
+const unsigned kDRegSizeInBytesLog2 = kDRegSizeLog2 - 3;
+const uint64_t kWRegMask = UINT64_C(0xffffffff);
+const uint64_t kXRegMask = UINT64_C(0xffffffffffffffff);
+const uint64_t kSRegMask = UINT64_C(0xffffffff);
+const uint64_t kDRegMask = UINT64_C(0xffffffffffffffff);
+const uint64_t kSSignMask = UINT64_C(0x80000000);
+const uint64_t kDSignMask = UINT64_C(0x8000000000000000);
+const uint64_t kWSignMask = UINT64_C(0x80000000);
+const uint64_t kXSignMask = UINT64_C(0x8000000000000000);
+const uint64_t kByteMask = UINT64_C(0xff);
+const uint64_t kHalfWordMask = UINT64_C(0xffff);
+const uint64_t kWordMask = UINT64_C(0xffffffff);
+const uint64_t kXMaxUInt = UINT64_C(0xffffffffffffffff);
+const uint64_t kWMaxUInt = UINT64_C(0xffffffff);
+const int64_t kXMaxInt = INT64_C(0x7fffffffffffffff);
+const int64_t kXMinInt = INT64_C(0x8000000000000000);
+const int32_t kWMaxInt = INT32_C(0x7fffffff);
+const int32_t kWMinInt = INT32_C(0x80000000);
+const unsigned kLinkRegCode = 30;
+const unsigned kZeroRegCode = 31;
+const unsigned kSPRegInternalCode = 63;
+const unsigned kRegCodeMask = 0x1f;
+
+const unsigned kAddressTagOffset = 56;
+const unsigned kAddressTagWidth = 8;
+const uint64_t kAddressTagMask =
+    ((UINT64_C(1) << kAddressTagWidth) - 1) << kAddressTagOffset;
+VIXL_STATIC_ASSERT(kAddressTagMask == UINT64_C(0xff00000000000000));
+
+// AArch64 floating-point specifics. These match IEEE-754.
+const unsigned kDoubleMantissaBits = 52;
+const unsigned kDoubleExponentBits = 11;
+const unsigned kFloatMantissaBits = 23;
+const unsigned kFloatExponentBits = 8;
+
+// Floating-point infinity values.
+extern const float kFP32PositiveInfinity;
+extern const float kFP32NegativeInfinity;
+extern const double kFP64PositiveInfinity;
+extern const double kFP64NegativeInfinity;
+
+// The default NaN values (for FPCR.DN=1).
+extern const double kFP64DefaultNaN;
+extern const float kFP32DefaultNaN;
+
+
+enum LSDataSize {
+  LSByte        = 0,
+  LSHalfword    = 1,
+  LSWord        = 2,
+  LSDoubleWord  = 3
+};
+
+LSDataSize CalcLSPairDataSize(LoadStorePairOp op);
+
+enum ImmBranchType {
+  UnknownBranchType = 0,
+  CondBranchType    = 1,
+  UncondBranchType  = 2,
+  CompareBranchType = 3,
+  TestBranchType    = 4
+};
+
+enum AddrMode {
+  Offset,
+  PreIndex,
+  PostIndex
+};
+
+enum FPRounding {
+  // The first four values are encodable directly by FPCR<RMode>.
+  FPTieEven = 0x0,
+  FPPositiveInfinity = 0x1,
+  FPNegativeInfinity = 0x2,
+  FPZero = 0x3,
+
+  // The final rounding mode is only available when explicitly specified by the
+  // instruction (such as with fcvta). It cannot be set in FPCR.
+  FPTieAway
+};
+
+enum Reg31Mode {
+  Reg31IsStackPointer,
+  Reg31IsZeroRegister
+};
+
+// Instructions. ---------------------------------------------------------------
+
+class Instruction {
+ public:
+  Instr InstructionBits() const {
+    return *(reinterpret_cast<const Instr*>(this));
+  }
+
+  void SetInstructionBits(Instr new_instr) {
+    *(reinterpret_cast<Instr*>(this)) = new_instr;
+  }
+
+  int Bit(int pos) const {
+    return (InstructionBits() >> pos) & 1;
+  }
+
+  uint32_t Bits(int msb, int lsb) const {
+    return unsigned_bitextract_32(msb, lsb, InstructionBits());
+  }
+
+  int32_t SignedBits(int msb, int lsb) const {
+    int32_t bits = *(reinterpret_cast<const int32_t*>(this));
+    return signed_bitextract_32(msb, lsb, bits);
+  }
+
+  Instr Mask(uint32_t mask) const {
+    return InstructionBits() & mask;
+  }
+
+  #define DEFINE_GETTER(Name, HighBit, LowBit, Func)             \
+  int64_t Name() const { return Func(HighBit, LowBit); }
+  INSTRUCTION_FIELDS_LIST(DEFINE_GETTER)
+  #undef DEFINE_GETTER
+
+  // ImmPCRel is a compound field (not present in INSTRUCTION_FIELDS_LIST),
+  // formed from ImmPCRelLo and ImmPCRelHi.
+  int ImmPCRel() const {
+    int const offset = ((ImmPCRelHi() << ImmPCRelLo_width) | ImmPCRelLo());
+    int const width = ImmPCRelLo_width + ImmPCRelHi_width;
+    return signed_bitextract_32(width-1, 0, offset);
+  }
+
+  uint64_t ImmLogical() const;
+  float ImmFP32() const;
+  double ImmFP64() const;
+
+  LSDataSize SizeLSPair() const {
+    return CalcLSPairDataSize(
+             static_cast<LoadStorePairOp>(Mask(LoadStorePairMask)));
+  }
+
+  // Helpers.
+  bool IsCondBranchImm() const {
+    return Mask(ConditionalBranchFMask) == ConditionalBranchFixed;
+  }
+
+  bool IsUncondBranchImm() const {
+    return Mask(UnconditionalBranchFMask) == UnconditionalBranchFixed;
+  }
+
+  bool IsCompareBranch() const {
+    return Mask(CompareBranchFMask) == CompareBranchFixed;
+  }
+
+  bool IsTestBranch() const {
+    return Mask(TestBranchFMask) == TestBranchFixed;
+  }
+
+  bool IsPCRelAddressing() const {
+    return Mask(PCRelAddressingFMask) == PCRelAddressingFixed;
+  }
+
+  bool IsLogicalImmediate() const {
+    return Mask(LogicalImmediateFMask) == LogicalImmediateFixed;
+  }
+
+  bool IsAddSubImmediate() const {
+    return Mask(AddSubImmediateFMask) == AddSubImmediateFixed;
+  }
+
+  bool IsAddSubExtended() const {
+    return Mask(AddSubExtendedFMask) == AddSubExtendedFixed;
+  }
+
+  bool IsLoadOrStore() const {
+    return Mask(LoadStoreAnyFMask) == LoadStoreAnyFixed;
+  }
+
+  bool IsLoad() const;
+  bool IsStore() const;
+
+  bool IsLoadLiteral() const {
+    // This includes PRFM_lit.
+    return Mask(LoadLiteralFMask) == LoadLiteralFixed;
+  }
+
+  bool IsMovn() const {
+    return (Mask(MoveWideImmediateMask) == MOVN_x) ||
+           (Mask(MoveWideImmediateMask) == MOVN_w);
+  }
+
+  // Indicate whether Rd can be the stack pointer or the zero register. This
+  // does not check that the instruction actually has an Rd field.
+  Reg31Mode RdMode() const {
+    // The following instructions use sp or wsp as Rd:
+    //  Add/sub (immediate) when not setting the flags.
+    //  Add/sub (extended) when not setting the flags.
+    //  Logical (immediate) when not setting the flags.
+    // Otherwise, r31 is the zero register.
+    if (IsAddSubImmediate() || IsAddSubExtended()) {
+      if (Mask(AddSubSetFlagsBit)) {
+        return Reg31IsZeroRegister;
+      } else {
+        return Reg31IsStackPointer;
+      }
+    }
+    if (IsLogicalImmediate()) {
+      // Of the logical (immediate) instructions, only ANDS (and its aliases)
+      // can set the flags. The others can all write into sp.
+      // Note that some logical operations are not available to
+      // immediate-operand instructions, so we have to combine two masks here.
+      if (Mask(LogicalImmediateMask & LogicalOpMask) == ANDS) {
+        return Reg31IsZeroRegister;
+      } else {
+        return Reg31IsStackPointer;
+      }
+    }
+    return Reg31IsZeroRegister;
+  }
+
+  // Indicate whether Rn can be the stack pointer or the zero register. This
+  // does not check that the instruction actually has an Rn field.
+  Reg31Mode RnMode() const {
+    // The following instructions use sp or wsp as Rn:
+    //  All loads and stores.
+    //  Add/sub (immediate).
+    //  Add/sub (extended).
+    // Otherwise, r31 is the zero register.
+    if (IsLoadOrStore() || IsAddSubImmediate() || IsAddSubExtended()) {
+      return Reg31IsStackPointer;
+    }
+    return Reg31IsZeroRegister;
+  }
+
+  ImmBranchType BranchType() const {
+    if (IsCondBranchImm()) {
+      return CondBranchType;
+    } else if (IsUncondBranchImm()) {
+      return UncondBranchType;
+    } else if (IsCompareBranch()) {
+      return CompareBranchType;
+    } else if (IsTestBranch()) {
+      return TestBranchType;
+    } else {
+      return UnknownBranchType;
+    }
+  }
+
+  // Find the target of this instruction. 'this' may be a branch or a
+  // PC-relative addressing instruction.
+  const Instruction* ImmPCOffsetTarget() const;
+
+  // Patch a PC-relative offset to refer to 'target'. 'this' may be a branch or
+  // a PC-relative addressing instruction.
+  void SetImmPCOffsetTarget(const Instruction* target);
+  // Patch a literal load instruction to load from 'source'.
+  void SetImmLLiteral(const Instruction* source);
+
+  // Calculate the address of a literal referred to by a load-literal
+  // instruction, and return it as the specified type.
+  //
+  // The literal itself is safely mutable only if the backing buffer is safely
+  // mutable.
+  template <typename T>
+  T LiteralAddress() const {
+    uint64_t base_raw = reinterpret_cast<uintptr_t>(this);
+    ptrdiff_t offset = ImmLLiteral() << kLiteralEntrySizeLog2;
+    uint64_t address_raw = base_raw + offset;
+
+    // Cast the address using a C-style cast. A reinterpret_cast would be
+    // appropriate, but it can't cast one integral type to another.
+    T address = (T)(address_raw);
+
+    // Assert that the address can be represented by the specified type.
+    VIXL_ASSERT((uint64_t)(address) == address_raw);
+
+    return address;
+  }
+
+  uint32_t Literal32() const {
+    uint32_t literal;
+    memcpy(&literal, LiteralAddress<const void*>(), sizeof(literal));
+    return literal;
+  }
+
+  uint64_t Literal64() const {
+    uint64_t literal;
+    memcpy(&literal, LiteralAddress<const void*>(), sizeof(literal));
+    return literal;
+  }
+
+  float LiteralFP32() const {
+    return rawbits_to_float(Literal32());
+  }
+
+  double LiteralFP64() const {
+    return rawbits_to_double(Literal64());
+  }
+
+  const Instruction* NextInstruction() const {
+    return this + kInstructionSize;
+  }
+
+  const Instruction* InstructionAtOffset(int64_t offset) const {
+    VIXL_ASSERT(IsWordAligned(this + offset));
+    return this + offset;
+  }
+
+  template<typename T> static Instruction* Cast(T src) {
+    return reinterpret_cast<Instruction*>(src);
+  }
+
+  template<typename T> static const Instruction* CastConst(T src) {
+    return reinterpret_cast<const Instruction*>(src);
+  }
+
+ private:
+  int ImmBranch() const;
+
+  void SetPCRelImmTarget(const Instruction* target);
+  void SetBranchImmTarget(const Instruction* target);
+};
+}  // namespace vixl
+
+#endif  // VIXL_A64_INSTRUCTIONS_A64_H_
diff --git a/qemu/disas/libvixl/code-buffer.h b/qemu/disas/libvixl/code-buffer.h
new file mode 100644
index 000000000..da6233dd8
--- /dev/null
+++ b/qemu/disas/libvixl/code-buffer.h
@@ -0,0 +1,113 @@
+// Copyright 2014, ARM Limited
+// 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 ARM Limited 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 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 VIXL_CODE_BUFFER_H
+#define VIXL_CODE_BUFFER_H
+
+#include <string.h>
+#include "globals.h"
+
+namespace vixl {
+
+class CodeBuffer {
+ public:
+  explicit CodeBuffer(size_t capacity = 4 * KBytes);
+  CodeBuffer(void* buffer, size_t capacity);
+  ~CodeBuffer();
+
+  void Reset();
+
+  ptrdiff_t OffsetFrom(ptrdiff_t offset) const {
+    ptrdiff_t cursor_offset = cursor_ - buffer_;
+    VIXL_ASSERT((offset >= 0) && (offset <= cursor_offset));
+    return cursor_offset - offset;
+  }
+
+  ptrdiff_t CursorOffset() const {
+    return OffsetFrom(0);
+  }
+
+  template <typename T>
+  T GetOffsetAddress(ptrdiff_t offset) const {
+    VIXL_ASSERT((offset >= 0) && (offset <= (cursor_ - buffer_)));
+    return reinterpret_cast<T>(buffer_ + offset);
+  }
+
+  size_t RemainingBytes() const {
+    VIXL_ASSERT((cursor_ >= buffer_) && (cursor_ <= (buffer_ + capacity_)));
+    return (buffer_ + capacity_) - cursor_;
+  }
+
+  // A code buffer can emit:
+  //  * 32-bit data: instruction and constant.
+  //  * 64-bit data: constant.
+  //  * string: debug info.
+  void Emit32(uint32_t data) { Emit(data); }
+
+  void Emit64(uint64_t data) { Emit(data); }
+
+  void EmitString(const char* string);
+
+  // Align to kInstructionSize.
+  void Align();
+
+  size_t capacity() const { return capacity_; }
+
+  bool IsManaged() const { return managed_; }
+
+  void Grow(size_t new_capacity);
+
+  bool IsDirty() const { return dirty_; }
+
+  void SetClean() { dirty_ = false; }
+
+ private:
+  template <typename T>
+  void Emit(T value) {
+    VIXL_ASSERT(RemainingBytes() >= sizeof(value));
+    dirty_ = true;
+    memcpy(cursor_, &value, sizeof(value));
+    cursor_ += sizeof(value);
+  }
+
+  // Backing store of the buffer.
+  byte* buffer_;
+  // If true the backing store is allocated and deallocated by the buffer. The
+  // backing store can then grow on demand. If false the backing store is
+  // provided by the user and cannot be resized internally.
+  bool managed_;
+  // Pointer to the next location to be written.
+  byte* cursor_;
+  // True if there has been any write since the buffer was created or cleaned.
+  bool dirty_;
+  // Capacity in bytes of the backing store.
+  size_t capacity_;
+};
+
+}  // namespace vixl
+
+#endif  // VIXL_CODE_BUFFER_H
+
diff --git a/qemu/disas/libvixl/globals.h b/qemu/disas/libvixl/globals.h
new file mode 100644
index 000000000..0c2493105
--- /dev/null
+++ b/qemu/disas/libvixl/globals.h
@@ -0,0 +1,85 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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 VIXL_GLOBALS_H
+#define VIXL_GLOBALS_H
+
+// Get standard C99 macros for integer types.
+#ifndef __STDC_CONSTANT_MACROS
+#define __STDC_CONSTANT_MACROS
+#endif
+
+#ifndef __STDC_LIMIT_MACROS
+#define __STDC_LIMIT_MACROS
+#endif
+
+#ifndef __STDC_FORMAT_MACROS
+#define __STDC_FORMAT_MACROS
+#endif
+
+#include <stdint.h>
+#include <inttypes.h>
+
+#include <assert.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include "platform.h"
+
+
+typedef uint8_t byte;
+
+const int KBytes = 1024;
+const int MBytes = 1024 * KBytes;
+
+#define VIXL_ABORT() printf("in %s, line %i", __FILE__, __LINE__); abort()
+#ifdef VIXL_DEBUG
+  #define VIXL_ASSERT(condition) assert(condition)
+  #define VIXL_CHECK(condition) VIXL_ASSERT(condition)
+  #define VIXL_UNIMPLEMENTED() printf("UNIMPLEMENTED\t"); VIXL_ABORT()
+  #define VIXL_UNREACHABLE() printf("UNREACHABLE\t"); VIXL_ABORT()
+#else
+  #define VIXL_ASSERT(condition) ((void) 0)
+  #define VIXL_CHECK(condition) assert(condition)
+  #define VIXL_UNIMPLEMENTED() ((void) 0)
+  #define VIXL_UNREACHABLE() ((void) 0)
+#endif
+// This is not as powerful as template based assertions, but it is simple.
+// It assumes that the descriptions are unique. If this starts being a problem,
+// we can switch to a different implemention.
+#define VIXL_CONCAT(a, b) a##b
+#define VIXL_STATIC_ASSERT_LINE(line, condition) \
+  typedef char VIXL_CONCAT(STATIC_ASSERT_LINE_, line)[(condition) ? 1 : -1] \
+  __attribute__((unused))
+#define VIXL_STATIC_ASSERT(condition) VIXL_STATIC_ASSERT_LINE(__LINE__, condition) //NOLINT
+
+template <typename T> inline void USE(T) {}
+
+#define VIXL_ALIGNMENT_EXCEPTION() printf("ALIGNMENT EXCEPTION\t"); VIXL_ABORT()
+
+#endif  // VIXL_GLOBALS_H
diff --git a/qemu/disas/libvixl/platform.h b/qemu/disas/libvixl/platform.h
new file mode 100644
index 000000000..de2b110cc
--- /dev/null
+++ b/qemu/disas/libvixl/platform.h
@@ -0,0 +1,37 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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 PLATFORM_H
+#define PLATFORM_H
+
+// Define platform specific functionalities.
+#include <signal.h>
+
+namespace vixl {
+inline void HostBreakpoint() { raise(SIGINT); }
+}  // namespace vixl
+
+#endif
diff --git a/qemu/disas/libvixl/utils.cc b/qemu/disas/libvixl/utils.cc
new file mode 100644
index 000000000..80b132a11
--- /dev/null
+++ b/qemu/disas/libvixl/utils.cc
@@ -0,0 +1,151 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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.
+
+#include "utils.h"
+#include <stdio.h>
+
+namespace vixl {
+
+uint32_t float_to_rawbits(float value) {
+  uint32_t bits = 0;
+  memcpy(&bits, &value, 4);
+  return bits;
+}
+
+
+uint64_t double_to_rawbits(double value) {
+  uint64_t bits = 0;
+  memcpy(&bits, &value, 8);
+  return bits;
+}
+
+
+float rawbits_to_float(uint32_t bits) {
+  float value = 0.0;
+  memcpy(&value, &bits, 4);
+  return value;
+}
+
+
+double rawbits_to_double(uint64_t bits) {
+  double value = 0.0;
+  memcpy(&value, &bits, 8);
+  return value;
+}
+
+
+int CountLeadingZeros(uint64_t value, int width) {
+  VIXL_ASSERT((width == 32) || (width == 64));
+  int count = 0;
+  uint64_t bit_test = UINT64_C(1) << (width - 1);
+  while ((count < width) && ((bit_test & value) == 0)) {
+    count++;
+    bit_test >>= 1;
+  }
+  return count;
+}
+
+
+int CountLeadingSignBits(int64_t value, int width) {
+  VIXL_ASSERT((width == 32) || (width == 64));
+  if (value >= 0) {
+    return CountLeadingZeros(value, width) - 1;
+  } else {
+    return CountLeadingZeros(~value, width) - 1;
+  }
+}
+
+
+int CountTrailingZeros(uint64_t value, int width) {
+  VIXL_ASSERT((width == 32) || (width == 64));
+  int count = 0;
+  while ((count < width) && (((value >> count) & 1) == 0)) {
+    count++;
+  }
+  return count;
+}
+
+
+int CountSetBits(uint64_t value, int width) {
+  // TODO: Other widths could be added here, as the implementation already
+  // supports them.
+  VIXL_ASSERT((width == 32) || (width == 64));
+
+  // Mask out unused bits to ensure that they are not counted.
+  value &= (UINT64_C(0xffffffffffffffff) >> (64-width));
+
+  // Add up the set bits.
+  // The algorithm works by adding pairs of bit fields together iteratively,
+  // where the size of each bit field doubles each time.
+  // An example for an 8-bit value:
+  // Bits:  h  g  f  e  d  c  b  a
+  //         \ |   \ |   \ |   \ |
+  // value = h+g   f+e   d+c   b+a
+  //            \    |      \    |
+  // value =   h+g+f+e     d+c+b+a
+  //                  \          |
+  // value =       h+g+f+e+d+c+b+a
+  const uint64_t kMasks[] = {
+    UINT64_C(0x5555555555555555),
+    UINT64_C(0x3333333333333333),
+    UINT64_C(0x0f0f0f0f0f0f0f0f),
+    UINT64_C(0x00ff00ff00ff00ff),
+    UINT64_C(0x0000ffff0000ffff),
+    UINT64_C(0x00000000ffffffff),
+  };
+
+  for (unsigned i = 0; i < (sizeof(kMasks) / sizeof(kMasks[0])); i++) {
+    int shift = 1 << i;
+    value = ((value >> shift) & kMasks[i]) + (value & kMasks[i]);
+  }
+
+  return value;
+}
+
+
+uint64_t LowestSetBit(uint64_t value) {
+  return value & -value;
+}
+
+
+bool IsPowerOf2(int64_t value) {
+  return (value != 0) && ((value & (value - 1)) == 0);
+}
+
+
+unsigned CountClearHalfWords(uint64_t imm, unsigned reg_size) {
+  VIXL_ASSERT((reg_size % 8) == 0);
+  int count = 0;
+  for (unsigned i = 0; i < (reg_size / 16); i++) {
+    if ((imm & 0xffff) == 0) {
+      count++;
+    }
+    imm >>= 16;
+  }
+  return count;
+}
+
+}  // namespace vixl
diff --git a/qemu/disas/libvixl/utils.h b/qemu/disas/libvixl/utils.h
new file mode 100644
index 000000000..b4406263a
--- /dev/null
+++ b/qemu/disas/libvixl/utils.h
@@ -0,0 +1,211 @@
+// Copyright 2013, ARM Limited
+// 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 ARM Limited 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 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 VIXL_UTILS_H
+#define VIXL_UTILS_H
+
+#include <math.h>
+#include <string.h>
+#include "globals.h"
+
+namespace vixl {
+
+// Macros for compile-time format checking.
+#if defined(__GNUC__)
+#define PRINTF_CHECK(format_index, varargs_index) \
+  __attribute__((format(printf, format_index, varargs_index)))
+#else
+#define PRINTF_CHECK(format_index, varargs_index)
+#endif
+
+// Check number width.
+inline bool is_intn(unsigned n, int64_t x) {
+  VIXL_ASSERT((0 < n) && (n < 64));
+  int64_t limit = INT64_C(1) << (n - 1);
+  return (-limit <= x) && (x < limit);
+}
+
+inline bool is_uintn(unsigned n, int64_t x) {
+  VIXL_ASSERT((0 < n) && (n < 64));
+  return !(x >> n);
+}
+
+inline unsigned truncate_to_intn(unsigned n, int64_t x) {
+  VIXL_ASSERT((0 < n) && (n < 64));
+  return (x & ((INT64_C(1) << n) - 1));
+}
+
+#define INT_1_TO_63_LIST(V)                                                    \
+V(1)  V(2)  V(3)  V(4)  V(5)  V(6)  V(7)  V(8)                                 \
+V(9)  V(10) V(11) V(12) V(13) V(14) V(15) V(16)                                \
+V(17) V(18) V(19) V(20) V(21) V(22) V(23) V(24)                                \
+V(25) V(26) V(27) V(28) V(29) V(30) V(31) V(32)                                \
+V(33) V(34) V(35) V(36) V(37) V(38) V(39) V(40)                                \
+V(41) V(42) V(43) V(44) V(45) V(46) V(47) V(48)                                \
+V(49) V(50) V(51) V(52) V(53) V(54) V(55) V(56)                                \
+V(57) V(58) V(59) V(60) V(61) V(62) V(63)
+
+#define DECLARE_IS_INT_N(N)                                                    \
+inline bool is_int##N(int64_t x) { return is_intn(N, x); }
+#define DECLARE_IS_UINT_N(N)                                                   \
+inline bool is_uint##N(int64_t x) { return is_uintn(N, x); }
+#define DECLARE_TRUNCATE_TO_INT_N(N)                                           \
+inline int truncate_to_int##N(int x) { return truncate_to_intn(N, x); }
+INT_1_TO_63_LIST(DECLARE_IS_INT_N)
+INT_1_TO_63_LIST(DECLARE_IS_UINT_N)
+INT_1_TO_63_LIST(DECLARE_TRUNCATE_TO_INT_N)
+#undef DECLARE_IS_INT_N
+#undef DECLARE_IS_UINT_N
+#undef DECLARE_TRUNCATE_TO_INT_N
+
+// Bit field extraction.
+inline uint32_t unsigned_bitextract_32(int msb, int lsb, uint32_t x) {
+  return (x >> lsb) & ((1 << (1 + msb - lsb)) - 1);
+}
+
+inline uint64_t unsigned_bitextract_64(int msb, int lsb, uint64_t x) {
+  return (x >> lsb) & ((static_cast<uint64_t>(1) << (1 + msb - lsb)) - 1);
+}
+
+inline int32_t signed_bitextract_32(int msb, int lsb, int32_t x) {
+  return (x << (31 - msb)) >> (lsb + 31 - msb);
+}
+
+inline int64_t signed_bitextract_64(int msb, int lsb, int64_t x) {
+  return (x << (63 - msb)) >> (lsb + 63 - msb);
+}
+
+// Floating point representation.
+uint32_t float_to_rawbits(float value);
+uint64_t double_to_rawbits(double value);
+float rawbits_to_float(uint32_t bits);
+double rawbits_to_double(uint64_t bits);
+
+
+// NaN tests.
+inline bool IsSignallingNaN(double num) {
+  const uint64_t kFP64QuietNaNMask = UINT64_C(0x0008000000000000);
+  uint64_t raw = double_to_rawbits(num);
+  if (isnan(num) && ((raw & kFP64QuietNaNMask) == 0)) {
+    return true;
+  }
+  return false;
+}
+
+
+inline bool IsSignallingNaN(float num) {
+  const uint32_t kFP32QuietNaNMask = 0x00400000;
+  uint32_t raw = float_to_rawbits(num);
+  if (isnan(num) && ((raw & kFP32QuietNaNMask) == 0)) {
+    return true;
+  }
+  return false;
+}
+
+
+template <typename T>
+inline bool IsQuietNaN(T num) {
+  return isnan(num) && !IsSignallingNaN(num);
+}
+
+
+// Convert the NaN in 'num' to a quiet NaN.
+inline double ToQuietNaN(double num) {
+  const uint64_t kFP64QuietNaNMask = UINT64_C(0x0008000000000000);
+  VIXL_ASSERT(isnan(num));
+  return rawbits_to_double(double_to_rawbits(num) | kFP64QuietNaNMask);
+}
+
+
+inline float ToQuietNaN(float num) {
+  const uint32_t kFP32QuietNaNMask = 0x00400000;
+  VIXL_ASSERT(isnan(num));
+  return rawbits_to_float(float_to_rawbits(num) | kFP32QuietNaNMask);
+}
+
+
+// Fused multiply-add.
+inline double FusedMultiplyAdd(double op1, double op2, double a) {
+  return fma(op1, op2, a);
+}
+
+
+inline float FusedMultiplyAdd(float op1, float op2, float a) {
+  return fmaf(op1, op2, a);
+}
+
+
+// Bit counting.
+int CountLeadingZeros(uint64_t value, int width);
+int CountLeadingSignBits(int64_t value, int width);
+int CountTrailingZeros(uint64_t value, int width);
+int CountSetBits(uint64_t value, int width);
+uint64_t LowestSetBit(uint64_t value);
+bool IsPowerOf2(int64_t value);
+
+unsigned CountClearHalfWords(uint64_t imm, unsigned reg_size);
+
+// Pointer alignment
+// TODO: rename/refactor to make it specific to instructions.
+template<typename T>
+bool IsWordAligned(T pointer) {
+  VIXL_ASSERT(sizeof(pointer) == sizeof(intptr_t));   // NOLINT(runtime/sizeof)
+  return ((intptr_t)(pointer) & 3) == 0;
+}
+
+// Increment a pointer (up to 64 bits) until it has the specified alignment.
+template<class T>
+T AlignUp(T pointer, size_t alignment) {
+  // Use C-style casts to get static_cast behaviour for integral types (T), and
+  // reinterpret_cast behaviour for other types.
+
+  uint64_t pointer_raw = (uint64_t)pointer;
+  VIXL_STATIC_ASSERT(sizeof(pointer) <= sizeof(pointer_raw));
+
+  size_t align_step = (alignment - pointer_raw) % alignment;
+  VIXL_ASSERT((pointer_raw + align_step) % alignment == 0);
+
+  return (T)(pointer_raw + align_step);
+}
+
+// Decrement a pointer (up to 64 bits) until it has the specified alignment.
+template<class T>
+T AlignDown(T pointer, size_t alignment) {
+  // Use C-style casts to get static_cast behaviour for integral types (T), and
+  // reinterpret_cast behaviour for other types.
+
+  uint64_t pointer_raw = (uint64_t)pointer;
+  VIXL_STATIC_ASSERT(sizeof(pointer) <= sizeof(pointer_raw));
+
+  size_t align_step = pointer_raw % alignment;
+  VIXL_ASSERT((pointer_raw - align_step) % alignment == 0);
+
+  return (T)(pointer_raw - align_step);
+}
+
+}  // namespace vixl
+
+#endif  // VIXL_UTILS_H