AArch64: Add ARM64 Assembler

This patch adds the ARM64 Assembler and ManagedRegister backend.
The implementation of the Arm64Assembler class is based on VIXL (a
programmatic A64 Assembler - see external/vixl ).

Change-Id: I842fd574637a953c19631eedf26f6c70d9ed7f9e
Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com>

6 files changed, 1890 insertions, 0 deletions

diff --git a/compiler/utils/arm64/assembler_arm64.cc b/compiler/utils/arm64/assembler_arm64.cc
new file mode 100644
index 0000000..b364ba0
--- /dev/null
+++ b/compiler/utils/arm64/assembler_arm64.cc
@@ -0,0 +1,616 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "assembler_arm64.h"
+#include "base/logging.h"
+#include "entrypoints/quick/quick_entrypoints.h"
+#include "offsets.h"
+#include "thread.h"
+#include "utils.h"
+
+namespace art {
+namespace arm64 {
+
+#ifdef ___
+#error "ARM64 Assembler macro already defined."
+#else
+#define ___   vixl_masm_->
+#endif
+
+void Arm64Assembler::EmitSlowPaths() {
+  if (!exception_blocks_.empty()) {
+    for (size_t i = 0; i < exception_blocks_.size(); i++) {
+      EmitExceptionPoll(exception_blocks_.at(i));
+    }
+  }
+  ___ FinalizeCode();
+}
+
+size_t Arm64Assembler::CodeSize() const {
+  return ___ SizeOfCodeGenerated();
+}
+
+void Arm64Assembler::FinalizeInstructions(const MemoryRegion& region) {
+  // Copy the instructions from the buffer.
+  MemoryRegion from(reinterpret_cast<void*>(vixl_buf_), CodeSize());
+  region.CopyFrom(0, from);
+}
+
+void Arm64Assembler::GetCurrentThread(ManagedRegister tr) {
+  ___ Mov(reg_x(tr.AsArm64().AsCoreRegister()), reg_x(TR));
+}
+
+void Arm64Assembler::GetCurrentThread(FrameOffset offset, ManagedRegister /* scratch */) {
+  StoreToOffset(TR, SP, offset.Int32Value());
+}
+
+// See Arm64 PCS Section 5.2.2.1.
+void Arm64Assembler::IncreaseFrameSize(size_t adjust) {
+  CHECK_ALIGNED(adjust, kStackAlignment);
+  AddConstant(SP, -adjust);
+}
+
+// See Arm64 PCS Section 5.2.2.1.
+void Arm64Assembler::DecreaseFrameSize(size_t adjust) {
+  CHECK_ALIGNED(adjust, kStackAlignment);
+  AddConstant(SP, adjust);
+}
+
+void Arm64Assembler::AddConstant(Register rd, int32_t value, Condition cond) {
+  AddConstant(rd, rd, value, cond);
+}
+
+void Arm64Assembler::AddConstant(Register rd, Register rn, int32_t value,
+                                 Condition cond) {
+  if ((cond == AL) || (cond == NV)) {
+    // VIXL macro-assembler handles all variants.
+    ___ Add(reg_x(rd), reg_x(rn), value);
+  } else {
+    // ip1 = rd + value
+    // rd = cond ? ip1 : rn
+    CHECK_NE(rn, IP1);
+    ___ Add(reg_x(IP1), reg_x(rn), value);
+    ___ Csel(reg_x(rd), reg_x(IP1), reg_x(rd), COND_OP(cond));
+  }
+}
+
+void Arm64Assembler::StoreWToOffset(StoreOperandType type, WRegister source,
+                                    Register base, int32_t offset) {
+  switch (type) {
+    case kStoreByte:
+      ___ Strb(reg_w(source), MEM_OP(reg_x(base), offset));
+      break;
+    case kStoreHalfword:
+      ___ Strh(reg_w(source), MEM_OP(reg_x(base), offset));
+      break;
+    case kStoreWord:
+      ___ Str(reg_w(source), MEM_OP(reg_x(base), offset));
+      break;
+    default:
+      LOG(FATAL) << "UNREACHABLE";
+  }
+}
+
+void Arm64Assembler::StoreToOffset(Register source, Register base, int32_t offset) {
+  CHECK_NE(source, SP);
+  ___ Str(reg_x(source), MEM_OP(reg_x(base), offset));
+}
+
+void Arm64Assembler::StoreSToOffset(SRegister source, Register base, int32_t offset) {
+  ___ Str(reg_s(source), MEM_OP(reg_x(base), offset));
+}
+
+void Arm64Assembler::StoreDToOffset(DRegister source, Register base, int32_t offset) {
+  ___ Str(reg_d(source), MEM_OP(reg_x(base), offset));
+}
+
+void Arm64Assembler::Store(FrameOffset offs, ManagedRegister m_src, size_t size) {
+  Arm64ManagedRegister src = m_src.AsArm64();
+  if (src.IsNoRegister()) {
+    CHECK_EQ(0u, size);
+  } else if (src.IsWRegister()) {
+    CHECK_EQ(4u, size);
+    StoreWToOffset(kStoreWord, src.AsWRegister(), SP, offs.Int32Value());
+  } else if (src.IsCoreRegister()) {
+    CHECK_EQ(8u, size);
+    StoreToOffset(src.AsCoreRegister(), SP, offs.Int32Value());
+  } else if (src.IsSRegister()) {
+    StoreSToOffset(src.AsSRegister(), SP, offs.Int32Value());
+  } else {
+    CHECK(src.IsDRegister()) << src;
+    StoreDToOffset(src.AsDRegister(), SP, offs.Int32Value());
+  }
+}
+
+void Arm64Assembler::StoreRef(FrameOffset offs, ManagedRegister m_src) {
+  Arm64ManagedRegister src = m_src.AsArm64();
+  CHECK(src.IsCoreRegister()) << src;
+  StoreToOffset(src.AsCoreRegister(), SP, offs.Int32Value());
+}
+
+void Arm64Assembler::StoreRawPtr(FrameOffset offs, ManagedRegister m_src) {
+  Arm64ManagedRegister src = m_src.AsArm64();
+  CHECK(src.IsCoreRegister()) << src;
+  StoreToOffset(src.AsCoreRegister(), SP, offs.Int32Value());
+}
+
+void Arm64Assembler::StoreImmediateToFrame(FrameOffset offs, uint32_t imm,
+                                           ManagedRegister m_scratch) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  CHECK(scratch.IsCoreRegister()) << scratch;
+  LoadImmediate(scratch.AsCoreRegister(), imm);
+  StoreToOffset(scratch.AsCoreRegister(), SP, offs.Int32Value());
+}
+
+void Arm64Assembler::StoreImmediateToThread(ThreadOffset offs, uint32_t imm,
+                                            ManagedRegister m_scratch) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  CHECK(scratch.IsCoreRegister()) << scratch;
+  LoadImmediate(scratch.AsCoreRegister(), imm);
+  StoreToOffset(scratch.AsCoreRegister(), TR, offs.Int32Value());
+}
+
+void Arm64Assembler::StoreStackOffsetToThread(ThreadOffset tr_offs,
+                                              FrameOffset fr_offs,
+                                              ManagedRegister m_scratch) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  CHECK(scratch.IsCoreRegister()) << scratch;
+  AddConstant(scratch.AsCoreRegister(), SP, fr_offs.Int32Value());
+  StoreToOffset(scratch.AsCoreRegister(), TR, tr_offs.Int32Value());
+}
+
+void Arm64Assembler::StoreStackPointerToThread(ThreadOffset tr_offs) {
+  // Arm64 does not support: "str sp, [dest]" therefore we use IP1 as a temp reg.
+  ___ Mov(reg_x(IP1), reg_x(SP));
+  StoreToOffset(IP1, TR, tr_offs.Int32Value());
+}
+
+void Arm64Assembler::StoreSpanning(FrameOffset dest_off, ManagedRegister m_source,
+                                   FrameOffset in_off, ManagedRegister m_scratch) {
+  Arm64ManagedRegister source = m_source.AsArm64();
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  StoreToOffset(source.AsCoreRegister(), SP, dest_off.Int32Value());
+  LoadFromOffset(scratch.AsCoreRegister(), SP, in_off.Int32Value());
+  StoreToOffset(scratch.AsCoreRegister(), SP, dest_off.Int32Value() + 8);
+}
+
+// Load routines.
+void Arm64Assembler::LoadImmediate(Register dest, int32_t value,
+                                   Condition cond) {
+  if ((cond == AL) || (cond == NV)) {
+    ___ Mov(reg_x(dest), value);
+  } else {
+    // ip1 = value
+    // rd = cond ? ip1 : rd
+    if (value != 0) {
+      CHECK_NE(dest, IP1);
+      ___ Mov(reg_x(IP1), value);
+      ___ Csel(reg_x(dest), reg_x(IP1), reg_x(dest), COND_OP(cond));
+    } else {
+      ___ Csel(reg_x(dest), reg_x(XZR), reg_x(dest), COND_OP(cond));
+    }
+  }
+}
+
+void Arm64Assembler::LoadWFromOffset(LoadOperandType type, WRegister dest,
+                                     Register base, int32_t offset) {
+  switch (type) {
+    case kLoadSignedByte:
+      ___ Ldrsb(reg_w(dest), MEM_OP(reg_x(base), offset));
+      break;
+    case kLoadSignedHalfword:
+      ___ Ldrsh(reg_w(dest), MEM_OP(reg_x(base), offset));
+      break;
+    case kLoadUnsignedByte:
+      ___ Ldrb(reg_w(dest), MEM_OP(reg_x(base), offset));
+      break;
+    case kLoadUnsignedHalfword:
+      ___ Ldrh(reg_w(dest), MEM_OP(reg_x(base), offset));
+      break;
+    case kLoadWord:
+      ___ Ldr(reg_w(dest), MEM_OP(reg_x(base), offset));
+      break;
+    default:
+        LOG(FATAL) << "UNREACHABLE";
+  }
+}
+
+// Note: We can extend this member by adding load type info - see
+// sign extended A64 load variants.
+void Arm64Assembler::LoadFromOffset(Register dest, Register base,
+                                    int32_t offset) {
+  CHECK_NE(dest, SP);
+  ___ Ldr(reg_x(dest), MEM_OP(reg_x(base), offset));
+}
+
+void Arm64Assembler::LoadSFromOffset(SRegister dest, Register base,
+                                     int32_t offset) {
+  ___ Ldr(reg_s(dest), MEM_OP(reg_x(base), offset));
+}
+
+void Arm64Assembler::LoadDFromOffset(DRegister dest, Register base,
+                                     int32_t offset) {
+  ___ Ldr(reg_d(dest), MEM_OP(reg_x(base), offset));
+}
+
+void Arm64Assembler::Load(Arm64ManagedRegister dest, Register base,
+                          int32_t offset, size_t size) {
+  if (dest.IsNoRegister()) {
+    CHECK_EQ(0u, size) << dest;
+  } else if (dest.IsWRegister()) {
+    CHECK_EQ(4u, size) << dest;
+    ___ Ldr(reg_w(dest.AsWRegister()), MEM_OP(reg_x(base), offset));
+  } else if (dest.IsCoreRegister()) {
+    CHECK_EQ(8u, size) << dest;
+    CHECK_NE(dest.AsCoreRegister(), SP) << dest;
+    ___ Ldr(reg_x(dest.AsCoreRegister()), MEM_OP(reg_x(base), offset));
+  } else if (dest.IsSRegister()) {
+    ___ Ldr(reg_s(dest.AsSRegister()), MEM_OP(reg_x(base), offset));
+  } else {
+    CHECK(dest.IsDRegister()) << dest;
+    ___ Ldr(reg_d(dest.AsDRegister()), MEM_OP(reg_x(base), offset));
+  }
+}
+
+void Arm64Assembler::Load(ManagedRegister m_dst, FrameOffset src, size_t size) {
+  return Load(m_dst.AsArm64(), SP, src.Int32Value(), size);
+}
+
+void Arm64Assembler::Load(ManagedRegister m_dst, ThreadOffset src, size_t size) {
+  return Load(m_dst.AsArm64(), TR, src.Int32Value(), size);
+}
+
+void Arm64Assembler::LoadRef(ManagedRegister m_dst, FrameOffset offs) {
+  Arm64ManagedRegister dst = m_dst.AsArm64();
+  CHECK(dst.IsCoreRegister()) << dst;
+  LoadFromOffset(dst.AsCoreRegister(), SP, offs.Int32Value());
+}
+
+void Arm64Assembler::LoadRef(ManagedRegister m_dst, ManagedRegister m_base,
+                             MemberOffset offs) {
+  Arm64ManagedRegister dst = m_dst.AsArm64();
+  Arm64ManagedRegister base = m_base.AsArm64();
+  CHECK(dst.IsCoreRegister() && base.IsCoreRegister());
+  LoadFromOffset(dst.AsCoreRegister(), base.AsCoreRegister(), offs.Int32Value());
+}
+
+void Arm64Assembler::LoadRawPtr(ManagedRegister m_dst, ManagedRegister m_base, Offset offs) {
+  Arm64ManagedRegister dst = m_dst.AsArm64();
+  Arm64ManagedRegister base = m_base.AsArm64();
+  CHECK(dst.IsCoreRegister() && base.IsCoreRegister());
+  LoadFromOffset(dst.AsCoreRegister(), base.AsCoreRegister(), offs.Int32Value());
+}
+
+void Arm64Assembler::LoadRawPtrFromThread(ManagedRegister m_dst, ThreadOffset offs) {
+  Arm64ManagedRegister dst = m_dst.AsArm64();
+  CHECK(dst.IsCoreRegister()) << dst;
+  LoadFromOffset(dst.AsCoreRegister(), TR, offs.Int32Value());
+}
+
+// Copying routines.
+void Arm64Assembler::Move(ManagedRegister m_dst, ManagedRegister m_src, size_t size) {
+  Arm64ManagedRegister dst = m_dst.AsArm64();
+  Arm64ManagedRegister src = m_src.AsArm64();
+  if (!dst.Equals(src)) {
+    if (dst.IsCoreRegister()) {
+      CHECK(src.IsCoreRegister()) << src;
+      ___ Mov(reg_x(dst.AsCoreRegister()), reg_x(src.AsCoreRegister()));
+    } else if (dst.IsWRegister()) {
+      CHECK(src.IsWRegister()) << src;
+      ___ Mov(reg_w(dst.AsWRegister()), reg_w(src.AsWRegister()));
+    } else if (dst.IsSRegister()) {
+      CHECK(src.IsSRegister()) << src;
+      ___ Fmov(reg_s(dst.AsSRegister()), reg_s(src.AsSRegister()));
+    } else {
+      CHECK(dst.IsDRegister()) << dst;
+      CHECK(src.IsDRegister()) << src;
+      ___ Fmov(reg_d(dst.AsDRegister()), reg_d(src.AsDRegister()));
+    }
+  }
+}
+
+void Arm64Assembler::CopyRawPtrFromThread(FrameOffset fr_offs,
+                                          ThreadOffset tr_offs,
+                                          ManagedRegister m_scratch) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  CHECK(scratch.IsCoreRegister()) << scratch;
+  LoadFromOffset(scratch.AsCoreRegister(), TR, tr_offs.Int32Value());
+  StoreToOffset(scratch.AsCoreRegister(), SP, fr_offs.Int32Value());
+}
+
+void Arm64Assembler::CopyRawPtrToThread(ThreadOffset tr_offs,
+                                        FrameOffset fr_offs,
+                                        ManagedRegister m_scratch) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  CHECK(scratch.IsCoreRegister()) << scratch;
+  LoadFromOffset(scratch.AsCoreRegister(), SP, fr_offs.Int32Value());
+  StoreToOffset(scratch.AsCoreRegister(), TR, tr_offs.Int32Value());
+}
+
+void Arm64Assembler::CopyRef(FrameOffset dest, FrameOffset src,
+                             ManagedRegister m_scratch) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  CHECK(scratch.IsCoreRegister()) << scratch;
+  LoadFromOffset(scratch.AsCoreRegister(), SP, src.Int32Value());
+  StoreToOffset(scratch.AsCoreRegister(), SP, dest.Int32Value());
+}
+
+void Arm64Assembler::Copy(FrameOffset dest, FrameOffset src,
+                          ManagedRegister m_scratch, size_t size) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  CHECK(scratch.IsCoreRegister() || scratch.IsWRegister()) << scratch;
+  CHECK(size == 4 || size == 8) << size;
+  if (size == 4) {
+    LoadWFromOffset(kLoadWord, scratch.AsWRegister(), SP, src.Int32Value());
+    StoreWToOffset(kStoreWord, scratch.AsWRegister(), SP, dest.Int32Value());
+  } else if (size == 8) {
+    LoadFromOffset(scratch.AsCoreRegister(), SP, src.Int32Value());
+    StoreToOffset(scratch.AsCoreRegister(), SP, dest.Int32Value());
+  } else {
+    UNIMPLEMENTED(FATAL) << "We only support Copy() of size 4 and 8";
+  }
+}
+
+void Arm64Assembler::Copy(FrameOffset dest, ManagedRegister src_base, Offset src_offset,
+                          ManagedRegister m_scratch, size_t size) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  Arm64ManagedRegister base = src_base.AsArm64();
+  CHECK(base.IsCoreRegister()) << base;
+  CHECK(scratch.IsCoreRegister() || scratch.IsWRegister()) << scratch;
+  CHECK(size == 4 || size == 8) << size;
+  if (size == 4) {
+    LoadWFromOffset(kLoadWord, scratch.AsWRegister(), base.AsCoreRegister(),
+                   src_offset.Int32Value());
+    StoreWToOffset(kStoreWord, scratch.AsWRegister(), SP, dest.Int32Value());
+  } else if (size == 8) {
+    LoadFromOffset(scratch.AsCoreRegister(), base.AsCoreRegister(), src_offset.Int32Value());
+    StoreToOffset(scratch.AsCoreRegister(), SP, dest.Int32Value());
+  } else {
+    UNIMPLEMENTED(FATAL) << "We only support Copy() of size 4 and 8";
+  }
+}
+
+void Arm64Assembler::Copy(ManagedRegister m_dest_base, Offset dest_offs, FrameOffset src,
+                          ManagedRegister m_scratch, size_t size) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  Arm64ManagedRegister base = m_dest_base.AsArm64();
+  CHECK(base.IsCoreRegister()) << base;
+  CHECK(scratch.IsCoreRegister() || scratch.IsWRegister()) << scratch;
+  CHECK(size == 4 || size == 8) << size;
+  if (size == 4) {
+    LoadWFromOffset(kLoadWord, scratch.AsWRegister(), SP, src.Int32Value());
+    StoreWToOffset(kStoreWord, scratch.AsWRegister(), base.AsCoreRegister(),
+                   dest_offs.Int32Value());
+  } else if (size == 8) {
+    LoadFromOffset(scratch.AsCoreRegister(), SP, src.Int32Value());
+    StoreToOffset(scratch.AsCoreRegister(), base.AsCoreRegister(), dest_offs.Int32Value());
+  } else {
+    UNIMPLEMENTED(FATAL) << "We only support Copy() of size 4 and 8";
+  }
+}
+
+void Arm64Assembler::Copy(FrameOffset /*dst*/, FrameOffset /*src_base*/, Offset /*src_offset*/,
+                          ManagedRegister /*mscratch*/, size_t /*size*/) {
+  UNIMPLEMENTED(FATAL) << "Unimplemented Copy() variant";
+}
+
+void Arm64Assembler::Copy(ManagedRegister m_dest, Offset dest_offset,
+                          ManagedRegister m_src, Offset src_offset,
+                          ManagedRegister m_scratch, size_t size) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  Arm64ManagedRegister src = m_src.AsArm64();
+  Arm64ManagedRegister dest = m_dest.AsArm64();
+  CHECK(dest.IsCoreRegister()) << dest;
+  CHECK(src.IsCoreRegister()) << src;
+  CHECK(scratch.IsCoreRegister() || scratch.IsWRegister()) << scratch;
+  CHECK(size == 4 || size == 8) << size;
+  if (size == 4) {
+    LoadWFromOffset(kLoadWord, scratch.AsWRegister(), src.AsCoreRegister(),
+                    src_offset.Int32Value());
+    StoreWToOffset(kStoreWord, scratch.AsWRegister(), dest.AsCoreRegister(),
+                   dest_offset.Int32Value());
+  } else if (size == 8) {
+    LoadFromOffset(scratch.AsCoreRegister(), src.AsCoreRegister(), src_offset.Int32Value());
+    StoreToOffset(scratch.AsCoreRegister(), dest.AsCoreRegister(), dest_offset.Int32Value());
+  } else {
+    UNIMPLEMENTED(FATAL) << "We only support Copy() of size 4 and 8";
+  }
+}
+
+void Arm64Assembler::Copy(FrameOffset /*dst*/, Offset /*dest_offset*/,
+                          FrameOffset /*src*/, Offset /*src_offset*/,
+                          ManagedRegister /*scratch*/, size_t /*size*/) {
+  UNIMPLEMENTED(FATAL) << "Unimplemented Copy() variant";
+}
+
+void Arm64Assembler::MemoryBarrier(ManagedRegister m_scratch) {
+  // TODO: Should we check that m_scratch is IP? - see arm.
+#if ANDROID_SMP != 0
+  ___ Dmb(vixl::InnerShareable, vixl::BarrierAll);
+#endif
+}
+
+void Arm64Assembler::SignExtend(ManagedRegister /*mreg*/, size_t /*size*/) {
+  UNIMPLEMENTED(FATAL) << "no sign extension necessary for Arm64";
+}
+
+void Arm64Assembler::ZeroExtend(ManagedRegister /*mreg*/, size_t /*size*/) {
+  UNIMPLEMENTED(FATAL) << "no zero extension necessary for Arm64";
+}
+
+void Arm64Assembler::VerifyObject(ManagedRegister /*src*/, bool /*could_be_null*/) {
+  // TODO: not validating references.
+}
+
+void Arm64Assembler::VerifyObject(FrameOffset /*src*/, bool /*could_be_null*/) {
+  // TODO: not validating references.
+}
+
+void Arm64Assembler::Call(ManagedRegister m_base, Offset offs, ManagedRegister m_scratch) {
+  Arm64ManagedRegister base = m_base.AsArm64();
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  CHECK(base.IsCoreRegister()) << base;
+  CHECK(scratch.IsCoreRegister()) << scratch;
+  LoadFromOffset(scratch.AsCoreRegister(), base.AsCoreRegister(), offs.Int32Value());
+  ___ Blr(reg_x(scratch.AsCoreRegister()));
+}
+
+void Arm64Assembler::Call(FrameOffset base, Offset offs, ManagedRegister m_scratch) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  CHECK(scratch.IsCoreRegister()) << scratch;
+  // Call *(*(SP + base) + offset)
+  LoadFromOffset(scratch.AsCoreRegister(), SP, base.Int32Value());
+  LoadFromOffset(scratch.AsCoreRegister(), scratch.AsCoreRegister(), offs.Int32Value());
+  ___ Blr(reg_x(scratch.AsCoreRegister()));
+}
+
+void Arm64Assembler::Call(ThreadOffset /*offset*/, ManagedRegister /*scratch*/) {
+  UNIMPLEMENTED(FATAL) << "Unimplemented Call() variant";
+}
+
+void Arm64Assembler::CreateSirtEntry(ManagedRegister m_out_reg, FrameOffset sirt_offs,
+                                     ManagedRegister m_in_reg, bool null_allowed) {
+  Arm64ManagedRegister out_reg = m_out_reg.AsArm64();
+  Arm64ManagedRegister in_reg = m_in_reg.AsArm64();
+  // For now we only hold stale sirt entries in x registers.
+  CHECK(in_reg.IsNoRegister() || in_reg.IsCoreRegister()) << in_reg;
+  CHECK(out_reg.IsCoreRegister()) << out_reg;
+  if (null_allowed) {
+    // Null values get a SIRT entry value of 0.  Otherwise, the SIRT entry is
+    // the address in the SIRT holding the reference.
+    // e.g. out_reg = (handle == 0) ? 0 : (SP+handle_offset)
+    if (in_reg.IsNoRegister()) {
+      LoadFromOffset(out_reg.AsCoreRegister(), SP, sirt_offs.Int32Value());
+      in_reg = out_reg;
+    }
+    ___ Cmp(reg_x(in_reg.AsCoreRegister()), 0);
+    if (!out_reg.Equals(in_reg)) {
+      LoadImmediate(out_reg.AsCoreRegister(), 0, EQ);
+    }
+    AddConstant(out_reg.AsCoreRegister(), SP, sirt_offs.Int32Value(), NE);
+  } else {
+    AddConstant(out_reg.AsCoreRegister(), SP, sirt_offs.Int32Value(), AL);
+  }
+}
+
+void Arm64Assembler::CreateSirtEntry(FrameOffset out_off, FrameOffset sirt_offset,
+                                     ManagedRegister m_scratch, bool null_allowed) {
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  CHECK(scratch.IsCoreRegister()) << scratch;
+  if (null_allowed) {
+    LoadFromOffset(scratch.AsCoreRegister(), SP, sirt_offset.Int32Value());
+    // Null values get a SIRT entry value of 0.  Otherwise, the sirt entry is
+    // the address in the SIRT holding the reference.
+    // e.g. scratch = (scratch == 0) ? 0 : (SP+sirt_offset)
+    ___ Cmp(reg_x(scratch.AsCoreRegister()), 0);
+    // Move this logic in add constants with flags.
+    AddConstant(scratch.AsCoreRegister(), SP, sirt_offset.Int32Value(), NE);
+  } else {
+    AddConstant(scratch.AsCoreRegister(), SP, sirt_offset.Int32Value(), AL);
+  }
+  StoreToOffset(scratch.AsCoreRegister(), SP, out_off.Int32Value());
+}
+
+void Arm64Assembler::LoadReferenceFromSirt(ManagedRegister m_out_reg,
+                                           ManagedRegister m_in_reg) {
+  Arm64ManagedRegister out_reg = m_out_reg.AsArm64();
+  Arm64ManagedRegister in_reg = m_in_reg.AsArm64();
+  CHECK(out_reg.IsCoreRegister()) << out_reg;
+  CHECK(in_reg.IsCoreRegister()) << in_reg;
+  vixl::Label exit;
+  if (!out_reg.Equals(in_reg)) {
+    // FIXME: Who sets the flags here?
+    LoadImmediate(out_reg.AsCoreRegister(), 0, EQ);
+  }
+  ___ Cmp(reg_x(in_reg.AsCoreRegister()), 0);
+  ___ B(&exit, COND_OP(EQ));
+  LoadFromOffset(out_reg.AsCoreRegister(), in_reg.AsCoreRegister(), 0);
+  ___ Bind(&exit);
+}
+
+void Arm64Assembler::ExceptionPoll(ManagedRegister m_scratch, size_t stack_adjust) {
+  CHECK_ALIGNED(stack_adjust, kStackAlignment);
+  Arm64ManagedRegister scratch = m_scratch.AsArm64();
+  Arm64Exception *current_exception = new Arm64Exception(scratch, stack_adjust);
+  exception_blocks_.push_back(current_exception);
+  LoadFromOffset(scratch.AsCoreRegister(), TR, Thread::ExceptionOffset().Int32Value());
+  ___ Cmp(reg_x(scratch.AsCoreRegister()), 0);
+  ___ B(current_exception->Entry(), COND_OP(NE));
+}
+
+void Arm64Assembler::EmitExceptionPoll(Arm64Exception *exception) {
+    // Bind exception poll entry.
+  ___ Bind(exception->Entry());
+  if (exception->stack_adjust_ != 0) {  // Fix up the frame.
+    DecreaseFrameSize(exception->stack_adjust_);
+  }
+  // Pass exception object as argument.
+  // Don't care about preserving X0 as this won't return.
+  ___ Mov(reg_x(X0), reg_x(exception->scratch_.AsCoreRegister()));
+  LoadFromOffset(IP1, TR, QUICK_ENTRYPOINT_OFFSET(pDeliverException).Int32Value());
+  ___ Blr(reg_x(IP1));
+  // Call should never return.
+  ___ Brk();
+}
+
+void Arm64Assembler::BuildFrame(size_t frame_size, ManagedRegister method_reg,
+                        const std::vector<ManagedRegister>& callee_save_regs,
+                        const std::vector<ManagedRegister>& entry_spills) {
+  CHECK_ALIGNED(frame_size, kStackAlignment);
+  CHECK(X0 == method_reg.AsArm64().AsCoreRegister());
+
+  // TODO: *create APCS FP - end of FP chain;
+  //       *add support for saving a different set of callee regs.
+  // For now we check that the size of callee regs vector is 20
+  // equivalent to the APCS callee saved regs [X19, x30] [D8, D15].
+  CHECK_EQ(callee_save_regs.size(), kCalleeSavedRegsSize);
+  ___ PushCalleeSavedRegisters();
+
+  // Increate frame to required size - must be at least space to push Method*.
+  CHECK_GT(frame_size, kCalleeSavedRegsSize * kPointerSize);
+  size_t adjust = frame_size - (kCalleeSavedRegsSize * kPointerSize);
+  IncreaseFrameSize(adjust);
+
+  // Write Method*.
+  StoreToOffset(X0, SP, 0);
+
+  // Write out entry spills, treated as X regs.
+  // TODO: we can implement a %2 STRP variant of StoreToOffset.
+  for (size_t i = 0; i < entry_spills.size(); ++i) {
+    Register reg = entry_spills.at(i).AsArm64().AsCoreRegister();
+    StoreToOffset(reg, SP, frame_size + kPointerSize + (i * kPointerSize));
+  }
+}
+
+void Arm64Assembler::RemoveFrame(size_t frame_size, const std::vector<ManagedRegister>& callee_save_regs) {
+  CHECK_ALIGNED(frame_size, kStackAlignment);
+
+  // For now we only check that the size of the frame is greater than the
+  // no of APCS callee saved regs [X19, X30] [D8, D15].
+  CHECK_EQ(callee_save_regs.size(), kCalleeSavedRegsSize);
+  CHECK_GT(frame_size, kCalleeSavedRegsSize * kPointerSize);
+
+  // Decrease frame size to start of callee saved regs.
+  size_t adjust = frame_size - (kCalleeSavedRegsSize * kPointerSize);
+  DecreaseFrameSize(adjust);
+
+  // Pop callee saved and return to LR.
+  ___ PopCalleeSavedRegisters();
+  ___ Ret();
+}
+
+}  // namespace arm64
+}  // namespace art
diff --git a/compiler/utils/arm64/assembler_arm64.h b/compiler/utils/arm64/assembler_arm64.h
new file mode 100644
index 0000000..70df252
--- /dev/null
+++ b/compiler/utils/arm64/assembler_arm64.h
@@ -0,0 +1,286 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_UTILS_ARM64_ASSEMBLER_ARM64_H_
+#define ART_COMPILER_UTILS_ARM64_ASSEMBLER_ARM64_H_
+
+#include <vector>
+
+#include "base/logging.h"
+#include "constants_arm64.h"
+#include "utils/arm64/managed_register_arm64.h"
+#include "utils/assembler.h"
+#include "offsets.h"
+#include "utils.h"
+#include "UniquePtr.h"
+#include "a64/macro-assembler-a64.h"
+#include "a64/disasm-a64.h"
+
+namespace art {
+namespace arm64 {
+
+#define MEM_OP(x...)      vixl::MemOperand(x)
+#define COND_OP(x)        static_cast<vixl::Condition>(x)
+
+enum Condition {
+  kNoCondition = -1,
+  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,    // Always.
+  NV = 15,    // Behaves as always/al.
+  kMaxCondition = 16,
+};
+
+enum LoadOperandType {
+  kLoadSignedByte,
+  kLoadUnsignedByte,
+  kLoadSignedHalfword,
+  kLoadUnsignedHalfword,
+  kLoadWord,
+  kLoadCoreWord,
+  kLoadSWord,
+  kLoadDWord
+};
+
+enum StoreOperandType {
+  kStoreByte,
+  kStoreHalfword,
+  kStoreWord,
+  kStoreCoreWord,
+  kStoreSWord,
+  kStoreDWord
+};
+
+class Arm64Exception;
+
+class Arm64Assembler : public Assembler {
+ public:
+  Arm64Assembler() : vixl_buf_(new byte[BUF_SIZE]),
+  vixl_masm_(new vixl::MacroAssembler(vixl_buf_, BUF_SIZE)) {}
+
+  virtual ~Arm64Assembler() {
+    if (kIsDebugBuild) {
+      vixl::Decoder *decoder = new vixl::Decoder();
+      vixl::PrintDisassembler *test = new vixl::PrintDisassembler(stdout);
+      decoder->AppendVisitor(test);
+
+      for (size_t i = 0; i < CodeSize() / vixl::kInstructionSize; ++i) {
+        vixl::Instruction *instr =
+          reinterpret_cast<vixl::Instruction*>(vixl_buf_ + i * vixl::kInstructionSize);
+        decoder->Decode(instr);
+      }
+    }
+    delete[] vixl_buf_;
+  }
+
+  // Emit slow paths queued during assembly.
+  void EmitSlowPaths();
+
+  // Size of generated code.
+  size_t CodeSize() const;
+
+  // Copy instructions out of assembly buffer into the given region of memory.
+  void FinalizeInstructions(const MemoryRegion& region);
+
+  // Emit code that will create an activation on the stack.
+  void BuildFrame(size_t frame_size, ManagedRegister method_reg,
+                  const std::vector<ManagedRegister>& callee_save_regs,
+                  const std::vector<ManagedRegister>& entry_spills);
+
+  // Emit code that will remove an activation from the stack.
+  void RemoveFrame(size_t frame_size,
+                   const std::vector<ManagedRegister>& callee_save_regs);
+
+  void IncreaseFrameSize(size_t adjust);
+  void DecreaseFrameSize(size_t adjust);
+
+  // Store routines.
+  void Store(FrameOffset offs, ManagedRegister src, size_t size);
+  void StoreRef(FrameOffset dest, ManagedRegister src);
+  void StoreRawPtr(FrameOffset dest, ManagedRegister src);
+  void StoreImmediateToFrame(FrameOffset dest, uint32_t imm,
+                                     ManagedRegister scratch);
+  void StoreImmediateToThread(ThreadOffset dest, uint32_t imm,
+                                      ManagedRegister scratch);
+  void StoreStackOffsetToThread(ThreadOffset thr_offs,
+                                        FrameOffset fr_offs,
+                                        ManagedRegister scratch);
+  void StoreStackPointerToThread(ThreadOffset thr_offs);
+  void StoreSpanning(FrameOffset dest, ManagedRegister src,
+                             FrameOffset in_off, ManagedRegister scratch);
+
+  // Load routines.
+  void Load(ManagedRegister dest, FrameOffset src, size_t size);
+  void Load(ManagedRegister dest, ThreadOffset src, size_t size);
+  void LoadRef(ManagedRegister dest, FrameOffset  src);
+  void LoadRef(ManagedRegister dest, ManagedRegister base,
+               MemberOffset offs);
+  void LoadRawPtr(ManagedRegister dest, ManagedRegister base,
+                  Offset offs);
+  void LoadRawPtrFromThread(ManagedRegister dest,
+                            ThreadOffset offs);
+  // Copying routines.
+  void Move(ManagedRegister dest, ManagedRegister src, size_t size);
+  void CopyRawPtrFromThread(FrameOffset fr_offs, ThreadOffset thr_offs,
+                            ManagedRegister scratch);
+  void CopyRawPtrToThread(ThreadOffset thr_offs, FrameOffset fr_offs,
+                          ManagedRegister scratch);
+  void CopyRef(FrameOffset dest, FrameOffset src,
+               ManagedRegister scratch);
+  void Copy(FrameOffset dest, FrameOffset src, ManagedRegister scratch, size_t size);
+  void Copy(FrameOffset dest, ManagedRegister src_base, Offset src_offset,
+            ManagedRegister scratch, size_t size);
+  void Copy(ManagedRegister dest_base, Offset dest_offset, FrameOffset src,
+            ManagedRegister scratch, size_t size);
+  void Copy(FrameOffset dest, FrameOffset src_base, Offset src_offset,
+            ManagedRegister scratch, size_t size);
+  void Copy(ManagedRegister dest, Offset dest_offset,
+            ManagedRegister src, Offset src_offset,
+            ManagedRegister scratch, size_t size);
+  void Copy(FrameOffset dest, Offset dest_offset, FrameOffset src, Offset src_offset,
+            ManagedRegister scratch, size_t size);
+  void MemoryBarrier(ManagedRegister scratch);
+
+  // Sign extension.
+  void SignExtend(ManagedRegister mreg, size_t size);
+
+  // Zero extension.
+  void ZeroExtend(ManagedRegister mreg, size_t size);
+
+  // Exploit fast access in managed code to Thread::Current().
+  void GetCurrentThread(ManagedRegister tr);
+  void GetCurrentThread(FrameOffset dest_offset,
+                        ManagedRegister scratch);
+
+  // Set up out_reg to hold a Object** into the SIRT, or to be NULL if the
+  // value is null and null_allowed. in_reg holds a possibly stale reference
+  // that can be used to avoid loading the SIRT entry to see if the value is
+  // NULL.
+  void CreateSirtEntry(ManagedRegister out_reg, FrameOffset sirt_offset,
+                       ManagedRegister in_reg, bool null_allowed);
+
+  // Set up out_off to hold a Object** into the SIRT, or to be NULL if the
+  // value is null and null_allowed.
+  void CreateSirtEntry(FrameOffset out_off, FrameOffset sirt_offset,
+                       ManagedRegister scratch, bool null_allowed);
+
+  // src holds a SIRT entry (Object**) load this into dst.
+  void LoadReferenceFromSirt(ManagedRegister dst,
+                             ManagedRegister src);
+
+  // Heap::VerifyObject on src. In some cases (such as a reference to this) we
+  // know that src may not be null.
+  void VerifyObject(ManagedRegister src, bool could_be_null);
+  void VerifyObject(FrameOffset src, bool could_be_null);
+
+  // Call to address held at [base+offset].
+  void Call(ManagedRegister base, Offset offset, ManagedRegister scratch);
+  void Call(FrameOffset base, Offset offset, ManagedRegister scratch);
+  void Call(ThreadOffset offset, ManagedRegister scratch);
+
+  // Generate code to check if Thread::Current()->exception_ is non-null
+  // and branch to a ExceptionSlowPath if it is.
+  void ExceptionPoll(ManagedRegister scratch, size_t stack_adjust);
+
+ private:
+  static vixl::Register reg_x(int code) {
+    CHECK(code < kNumberOfCoreRegisters) << code;
+    if (code == SP) {
+      return vixl::sp;
+    }
+    return vixl::Register::XRegFromCode(code);
+  }
+
+  static vixl::Register reg_w(int code) {
+    return vixl::Register::WRegFromCode(code);
+  }
+
+  static vixl::FPRegister reg_d(int code) {
+    return vixl::FPRegister::DRegFromCode(code);
+  }
+
+  static vixl::FPRegister reg_s(int code) {
+    return vixl::FPRegister::SRegFromCode(code);
+  }
+
+  // Emits Exception block.
+  void EmitExceptionPoll(Arm64Exception *exception);
+
+  void StoreWToOffset(StoreOperandType type, WRegister source,
+                      Register base, int32_t offset);
+  void StoreToOffset(Register source, Register base, int32_t offset);
+  void StoreSToOffset(SRegister source, Register base, int32_t offset);
+  void StoreDToOffset(DRegister source, Register base, int32_t offset);
+
+  void LoadImmediate(Register dest, int32_t value, Condition cond = AL);
+  void Load(Arm64ManagedRegister dst, Register src, int32_t src_offset, size_t size);
+  void LoadWFromOffset(LoadOperandType type, WRegister dest,
+                      Register base, int32_t offset);
+  void LoadFromOffset(Register dest, Register base, int32_t offset);
+  void LoadSFromOffset(SRegister dest, Register base, int32_t offset);
+  void LoadDFromOffset(DRegister dest, Register base, int32_t offset);
+  void AddConstant(Register rd, int32_t value, Condition cond = AL);
+  void AddConstant(Register rd, Register rn, int32_t value, Condition cond = AL);
+
+  // Vixl buffer size.
+  static constexpr size_t BUF_SIZE = 4096;
+
+  // Vixl buffer.
+  byte* vixl_buf_;
+
+  // Unique ptr - vixl assembler.
+  UniquePtr<vixl::MacroAssembler> vixl_masm_;
+
+  // List of exception blocks to generate at the end of the code cache.
+  std::vector<Arm64Exception*> exception_blocks_;
+};
+
+class Arm64Exception {
+ private:
+  explicit Arm64Exception(Arm64ManagedRegister scratch, size_t stack_adjust)
+      : scratch_(scratch), stack_adjust_(stack_adjust) {
+    }
+
+  vixl::Label* Entry() { return &exception_entry_; }
+
+  // Register used for passing Thread::Current()->exception_ .
+  const Arm64ManagedRegister scratch_;
+
+  // Stack adjust for ExceptionPool.
+  const size_t stack_adjust_;
+
+  vixl::Label exception_entry_;
+
+  friend class Arm64Assembler;
+  DISALLOW_COPY_AND_ASSIGN(Arm64Exception);
+};
+
+}  // namespace arm64
+}  // namespace art
+
+#endif  // ART_COMPILER_UTILS_ARM64_ASSEMBLER_ARM64_H_
diff --git a/compiler/utils/arm64/constants_arm64.h b/compiler/utils/arm64/constants_arm64.h
new file mode 100644
index 0000000..c05c2f1
--- /dev/null
+++ b/compiler/utils/arm64/constants_arm64.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_UTILS_ARM64_CONSTANTS_ARM64_H_
+#define ART_COMPILER_UTILS_ARM64_CONSTANTS_ARM64_H_
+
+#include <stdint.h>
+#include <iosfwd>
+#include "arch/arm64/registers_arm64.h"
+#include "base/casts.h"
+#include "base/logging.h"
+#include "globals.h"
+
+// TODO: Extend this file by adding missing functionality.
+
+namespace art {
+namespace arm64 {
+
+  constexpr unsigned int kCalleeSavedRegsSize = 20;
+
+}  // arm64
+}  // art
+
+#endif  // ART_COMPILER_UTILS_ARM64_CONSTANTS_ARM64_H_
diff --git a/compiler/utils/arm64/managed_register_arm64.cc b/compiler/utils/arm64/managed_register_arm64.cc
new file mode 100644
index 0000000..cc0b509
--- /dev/null
+++ b/compiler/utils/arm64/managed_register_arm64.cc
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "managed_register_arm64.h"
+#include "globals.h"
+
+namespace art {
+namespace arm64 {
+
+// TODO: Define convention
+//
+// Do not use APCS callee saved regs for now. Use:
+//  * [X0, X15]
+//  * [W0, W15]
+//  * [D0, D31]
+//  * [S0, S31]
+static const int kNumberOfAvailableCoreRegisters = (X15 - X0) + 1;
+static const int kNumberOfAvailableWRegisters = (W15 - W0) + 1;
+static const int kNumberOfAvailableDRegisters = kNumberOfDRegisters;
+static const int kNumberOfAvailableSRegisters = kNumberOfSRegisters;
+
+// Returns true if this managed-register overlaps the other managed-register.
+// GP Register Bank:
+//       31____0 W[n]
+// 63__________0 X[n]
+//
+// FP Register Bank:
+//       31____0 S[n]
+// 63__________0 D[n]
+bool Arm64ManagedRegister::Overlaps(const Arm64ManagedRegister& other) const {
+  if (IsNoRegister() || other.IsNoRegister()) return false;
+  if ((IsGPRegister() && other.IsGPRegister()) ||
+      (IsFPRegister() && other.IsFPRegister())) {
+    return (RegNo() == other.RegNo());
+  }
+  return false;
+}
+
+int Arm64ManagedRegister::RegNo() const {
+  CHECK(!IsNoRegister());
+  int no;
+  if (IsCoreRegister()) {
+    if (IsStackPointer()) {
+      no = static_cast<int>(X31);
+    } else {
+      no = static_cast<int>(AsCoreRegister());
+    }
+  } else if (IsWRegister()) {
+    no = static_cast<int>(AsWRegister());
+  } else if (IsDRegister()) {
+    no = static_cast<int>(AsDRegister());
+  } else if (IsSRegister()) {
+    no = static_cast<int>(AsSRegister());
+  } else {
+    no = kNoRegister;
+  }
+  return no;
+}
+
+int Arm64ManagedRegister::RegIdLow() const {
+  CHECK(IsCoreRegister() || IsDRegister());
+  int low = RegNo();
+  if (IsCoreRegister()) {
+    low += kNumberOfCoreRegIds;
+  } else if (IsDRegister()) {
+    low += kNumberOfCoreRegIds + kNumberOfWRegIds + kNumberOfDRegIds;
+  }
+  return low;
+}
+
+// FIXME: Find better naming.
+int Arm64ManagedRegister::RegIdHigh() const {
+  CHECK(IsWRegister() || IsSRegister());
+  int high = RegNo();
+  if (IsSRegister()) {
+    high += kNumberOfCoreRegIds + kNumberOfWRegIds;
+  }
+  return high;
+}
+
+void Arm64ManagedRegister::Print(std::ostream& os) const {
+  if (!IsValidManagedRegister()) {
+    os << "No Register";
+  } else if (IsCoreRegister()) {
+    os << "XCore: " << static_cast<int>(AsCoreRegister());
+  } else if (IsWRegister()) {
+    os << "WCore: " << static_cast<int>(AsWRegister());
+  } else if (IsDRegister()) {
+    os << "DRegister: " << static_cast<int>(AsDRegister());
+  } else if (IsSRegister()) {
+    os << "SRegister: " << static_cast<int>(AsSRegister());
+  } else {
+    os << "??: " << RegId();
+  }
+}
+
+std::ostream& operator<<(std::ostream& os, const Arm64ManagedRegister& reg) {
+  reg.Print(os);
+  return os;
+}
+
+}  // namespace arm64
+}  // namespace art
diff --git a/compiler/utils/arm64/managed_register_arm64.h b/compiler/utils/arm64/managed_register_arm64.h
new file mode 100644
index 0000000..5df37cc
--- /dev/null
+++ b/compiler/utils/arm64/managed_register_arm64.h
@@ -0,0 +1,224 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_COMPILER_UTILS_ARM64_MANAGED_REGISTER_ARM64_H_
+#define ART_COMPILER_UTILS_ARM64_MANAGED_REGISTER_ARM64_H_
+
+#include "base/logging.h"
+#include "constants_arm64.h"
+#include "utils/managed_register.h"
+
+namespace art {
+namespace arm64 {
+
+const int kNumberOfCoreRegIds = kNumberOfCoreRegisters;
+const int kNumberOfWRegIds = kNumberOfWRegisters;
+const int kNumberOfDRegIds = kNumberOfDRegisters;
+const int kNumberOfSRegIds = kNumberOfSRegisters;
+
+const int kNumberOfRegIds = kNumberOfCoreRegIds + kNumberOfWRegIds +
+  kNumberOfDRegIds + kNumberOfSRegIds;
+
+// Register ids map:
+//  [0..X[  core registers 64bit (enum Register)
+//  [X..W[  core registers 32bit (enum WRegister)
+//  [W..D[  double precision VFP registers (enum DRegister)
+//  [D..S[  single precision VFP registers (enum SRegister)
+//
+// where:
+//  X = kNumberOfCoreRegIds
+//  W = X + kNumberOfWRegIds
+//  D = W + kNumberOfDRegIds
+//  S = D + kNumberOfSRegIds
+//
+// An instance of class 'ManagedRegister' represents a single Arm64
+// register. A register can be one of the following:
+//  * core register 64bit context (enum Register)
+//  * core register 32bit context (enum WRegister)
+//  * VFP double precision register (enum DRegister)
+//  * VFP single precision register (enum SRegister)
+//
+// There is a one to one mapping between ManagedRegister and register id.
+
+class Arm64ManagedRegister : public ManagedRegister {
+ public:
+  Register AsCoreRegister() const {
+    CHECK(IsCoreRegister());
+    return static_cast<Register>(id_);
+  }
+
+  WRegister AsWRegister() const {
+    CHECK(IsWRegister());
+    return static_cast<WRegister>(id_ - kNumberOfCoreRegIds);
+  }
+
+  DRegister AsDRegister() const {
+    CHECK(IsDRegister());
+    return static_cast<DRegister>(id_ - kNumberOfCoreRegIds - kNumberOfWRegIds);
+  }
+
+  SRegister AsSRegister() const {
+    CHECK(IsSRegister());
+    return static_cast<SRegister>(id_ - kNumberOfCoreRegIds - kNumberOfWRegIds -
+                                  kNumberOfDRegIds);
+  }
+
+  WRegister AsOverlappingCoreRegisterLow() const {
+    CHECK(IsValidManagedRegister());
+    if (IsStackPointer()) return W31;
+    return static_cast<WRegister>(AsCoreRegister());
+  }
+
+  // FIXME: Find better naming.
+  Register AsOverlappingWRegisterCore() const {
+    CHECK(IsValidManagedRegister());
+    return static_cast<Register>(AsWRegister());
+  }
+
+  SRegister AsOverlappingDRegisterLow() const {
+    CHECK(IsValidManagedRegister());
+    return static_cast<SRegister>(AsDRegister());
+  }
+
+  // FIXME: Find better naming.
+  DRegister AsOverlappingSRegisterD() const {
+    CHECK(IsValidManagedRegister());
+    return static_cast<DRegister>(AsSRegister());
+  }
+
+  bool IsCoreRegister() const {
+    CHECK(IsValidManagedRegister());
+    return (0 <= id_) && (id_ < kNumberOfCoreRegIds);
+  }
+
+  bool IsWRegister() const {
+    CHECK(IsValidManagedRegister());
+    const int test = id_ - kNumberOfCoreRegIds;
+    return (0 <= test) && (test < kNumberOfWRegIds);
+  }
+
+  bool IsDRegister() const {
+    CHECK(IsValidManagedRegister());
+    const int test = id_ - (kNumberOfCoreRegIds + kNumberOfWRegIds);
+    return (0 <= test) && (test < kNumberOfDRegIds);
+  }
+
+  bool IsSRegister() const {
+    CHECK(IsValidManagedRegister());
+    const int test = id_ - (kNumberOfCoreRegIds + kNumberOfWRegIds +
+                            kNumberOfDRegIds);
+    return (0 <= test) && (test < kNumberOfSRegIds);
+  }
+
+  bool IsGPRegister() const {
+    return IsCoreRegister() || IsWRegister();
+  }
+
+  bool IsFPRegister() const {
+    return IsDRegister() || IsSRegister();
+  }
+
+  bool IsSameType(Arm64ManagedRegister test) const {
+    CHECK(IsValidManagedRegister() && test.IsValidManagedRegister());
+    return
+      (IsCoreRegister() && test.IsCoreRegister()) ||
+      (IsWRegister() && test.IsWRegister()) ||
+      (IsDRegister() && test.IsDRegister()) ||
+      (IsSRegister() && test.IsSRegister());
+  }
+
+  // Returns true if the two managed-registers ('this' and 'other') overlap.
+  // Either managed-register may be the NoRegister. If both are the NoRegister
+  // then false is returned.
+  bool Overlaps(const Arm64ManagedRegister& other) const;
+
+  void Print(std::ostream& os) const;
+
+  static Arm64ManagedRegister FromCoreRegister(Register r) {
+    CHECK_NE(r, kNoRegister);
+    return FromRegId(r);
+  }
+
+  static Arm64ManagedRegister FromWRegister(WRegister r) {
+    CHECK_NE(r, kNoWRegister);
+    return FromRegId(r + kNumberOfCoreRegIds);
+  }
+
+  static Arm64ManagedRegister FromDRegister(DRegister r) {
+    CHECK_NE(r, kNoDRegister);
+    return FromRegId(r + (kNumberOfCoreRegIds + kNumberOfWRegIds));
+  }
+
+  static Arm64ManagedRegister FromSRegister(SRegister r) {
+    CHECK_NE(r, kNoSRegister);
+    return FromRegId(r + (kNumberOfCoreRegIds + kNumberOfWRegIds +
+                          kNumberOfDRegIds));
+  }
+
+  // Returns the X register overlapping W register r.
+  static Arm64ManagedRegister FromWRegisterCore(WRegister r) {
+    CHECK_NE(r, kNoWRegister);
+    return FromRegId(r);
+  }
+
+  // Return the D register overlapping S register r.
+  static Arm64ManagedRegister FromSRegisterD(SRegister r) {
+    CHECK_NE(r, kNoSRegister);
+    return FromRegId(r + (kNumberOfCoreRegIds + kNumberOfWRegIds));
+  }
+
+ private:
+  bool IsValidManagedRegister() const {
+    return (0 <= id_) && (id_ < kNumberOfRegIds);
+  }
+
+  bool IsStackPointer() const {
+    return IsCoreRegister() && (id_ == SP);
+  }
+
+  int RegId() const {
+    CHECK(!IsNoRegister());
+    return id_;
+  }
+
+  int RegNo() const;
+  int RegIdLow() const;
+  int RegIdHigh() const;
+
+  friend class ManagedRegister;
+
+  explicit Arm64ManagedRegister(int reg_id) : ManagedRegister(reg_id) {}
+
+  static Arm64ManagedRegister FromRegId(int reg_id) {
+    Arm64ManagedRegister reg(reg_id);
+    CHECK(reg.IsValidManagedRegister());
+    return reg;
+  }
+};
+
+std::ostream& operator<<(std::ostream& os, const Arm64ManagedRegister& reg);
+
+}  // namespace arm64
+
+inline arm64::Arm64ManagedRegister ManagedRegister::AsArm64() const {
+  arm64::Arm64ManagedRegister reg(id_);
+  CHECK(reg.IsNoRegister() || reg.IsValidManagedRegister());
+  return reg;
+}
+
+}  // namespace art
+
+#endif  // ART_COMPILER_UTILS_ARM64_MANAGED_REGISTER_ARM64_H_
diff --git a/compiler/utils/arm64/managed_register_arm64_test.cc b/compiler/utils/arm64/managed_register_arm64_test.cc
new file mode 100644
index 0000000..3d98e12
--- /dev/null
+++ b/compiler/utils/arm64/managed_register_arm64_test.cc
@@ -0,0 +1,611 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "globals.h"
+#include "managed_register_arm64.h"
+#include "gtest/gtest.h"
+
+namespace art {
+namespace arm64 {
+
+TEST(Arm64ManagedRegister, NoRegister) {
+  Arm64ManagedRegister reg = ManagedRegister::NoRegister().AsArm64();
+  EXPECT_TRUE(reg.IsNoRegister());
+  EXPECT_TRUE(!reg.Overlaps(reg));
+}
+
+// X Register test.
+TEST(Arm64ManagedRegister, CoreRegister) {
+  Arm64ManagedRegister reg = Arm64ManagedRegister::FromCoreRegister(X0);
+  Arm64ManagedRegister wreg = Arm64ManagedRegister::FromWRegister(W0);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(wreg));
+  EXPECT_EQ(X0, reg.AsCoreRegister());
+
+  reg = Arm64ManagedRegister::FromCoreRegister(X1);
+  wreg = Arm64ManagedRegister::FromWRegister(W1);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(wreg));
+  EXPECT_EQ(X1, reg.AsCoreRegister());
+
+  reg = Arm64ManagedRegister::FromCoreRegister(X7);
+  wreg = Arm64ManagedRegister::FromWRegister(W7);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(wreg));
+  EXPECT_EQ(X7, reg.AsCoreRegister());
+
+  reg = Arm64ManagedRegister::FromCoreRegister(X15);
+  wreg = Arm64ManagedRegister::FromWRegister(W15);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(wreg));
+  EXPECT_EQ(X15, reg.AsCoreRegister());
+
+  reg = Arm64ManagedRegister::FromCoreRegister(X19);
+  wreg = Arm64ManagedRegister::FromWRegister(W19);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(wreg));
+  EXPECT_EQ(X19, reg.AsCoreRegister());
+
+  reg = Arm64ManagedRegister::FromCoreRegister(X16);
+  wreg = Arm64ManagedRegister::FromWRegister(W16);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(wreg));
+  EXPECT_EQ(IP0, reg.AsCoreRegister());
+
+  reg = Arm64ManagedRegister::FromCoreRegister(SP);
+  wreg = Arm64ManagedRegister::FromWRegister(WZR);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(wreg));
+  EXPECT_EQ(SP, reg.AsCoreRegister());
+}
+
+// W register test.
+TEST(Arm64ManagedRegister, WRegister) {
+  Arm64ManagedRegister reg = Arm64ManagedRegister::FromWRegister(W0);
+  Arm64ManagedRegister xreg = Arm64ManagedRegister::FromCoreRegister(X0);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(xreg));
+  EXPECT_EQ(W0, reg.AsWRegister());
+
+  reg = Arm64ManagedRegister::FromWRegister(W5);
+  xreg = Arm64ManagedRegister::FromCoreRegister(X5);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(xreg));
+  EXPECT_EQ(W5, reg.AsWRegister());
+
+  reg = Arm64ManagedRegister::FromWRegister(W6);
+  xreg = Arm64ManagedRegister::FromCoreRegister(X6);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(xreg));
+  EXPECT_EQ(W6, reg.AsWRegister());
+
+  reg = Arm64ManagedRegister::FromWRegister(W18);
+  xreg = Arm64ManagedRegister::FromCoreRegister(X18);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(xreg));
+  EXPECT_EQ(W18, reg.AsWRegister());
+
+  reg = Arm64ManagedRegister::FromWRegister(W29);
+  xreg = Arm64ManagedRegister::FromCoreRegister(FP);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(xreg));
+  EXPECT_EQ(W29, reg.AsWRegister());
+
+  reg = Arm64ManagedRegister::FromWRegister(WZR);
+  xreg = Arm64ManagedRegister::FromCoreRegister(SP);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(reg.IsWRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(xreg));
+  EXPECT_EQ(W31, reg.AsWRegister());
+}
+
+// D Register test.
+TEST(Arm64ManagedRegister, DRegister) {
+  Arm64ManagedRegister reg = Arm64ManagedRegister::FromDRegister(D0);
+  Arm64ManagedRegister sreg = Arm64ManagedRegister::FromSRegister(S0);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(sreg));
+  EXPECT_EQ(D0, reg.AsDRegister());
+  EXPECT_EQ(S0, reg.AsOverlappingDRegisterLow());
+  EXPECT_TRUE(reg.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+
+  reg = Arm64ManagedRegister::FromDRegister(D1);
+  sreg = Arm64ManagedRegister::FromSRegister(S1);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(sreg));
+  EXPECT_EQ(D1, reg.AsDRegister());
+  EXPECT_EQ(S1, reg.AsOverlappingDRegisterLow());
+  EXPECT_TRUE(reg.Equals(Arm64ManagedRegister::FromDRegister(D1)));
+
+  reg = Arm64ManagedRegister::FromDRegister(D20);
+  sreg = Arm64ManagedRegister::FromSRegister(S20);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(sreg));
+  EXPECT_EQ(D20, reg.AsDRegister());
+  EXPECT_EQ(S20, reg.AsOverlappingDRegisterLow());
+  EXPECT_TRUE(reg.Equals(Arm64ManagedRegister::FromDRegister(D20)));
+
+  reg = Arm64ManagedRegister::FromDRegister(D31);
+  sreg = Arm64ManagedRegister::FromSRegister(S31);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(reg.IsDRegister());
+  EXPECT_TRUE(!reg.IsSRegister());
+  EXPECT_TRUE(reg.Overlaps(sreg));
+  EXPECT_EQ(D31, reg.AsDRegister());
+  EXPECT_EQ(S31, reg.AsOverlappingDRegisterLow());
+  EXPECT_TRUE(reg.Equals(Arm64ManagedRegister::FromDRegister(D31)));
+}
+
+// S Register test.
+TEST(Arm64ManagedRegister, SRegister) {
+  Arm64ManagedRegister reg = Arm64ManagedRegister::FromSRegister(S0);
+  Arm64ManagedRegister dreg = Arm64ManagedRegister::FromDRegister(D0);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(reg.IsSRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(reg.Overlaps(dreg));
+  EXPECT_EQ(S0, reg.AsSRegister());
+  EXPECT_EQ(D0, reg.AsOverlappingSRegisterD());
+  EXPECT_TRUE(reg.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+
+  reg = Arm64ManagedRegister::FromSRegister(S5);
+  dreg = Arm64ManagedRegister::FromDRegister(D5);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(reg.IsSRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(reg.Overlaps(dreg));
+  EXPECT_EQ(S5, reg.AsSRegister());
+  EXPECT_EQ(D5, reg.AsOverlappingSRegisterD());
+  EXPECT_TRUE(reg.Equals(Arm64ManagedRegister::FromSRegister(S5)));
+
+  reg = Arm64ManagedRegister::FromSRegister(S7);
+  dreg = Arm64ManagedRegister::FromDRegister(D7);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(reg.IsSRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(reg.Overlaps(dreg));
+  EXPECT_EQ(S7, reg.AsSRegister());
+  EXPECT_EQ(D7, reg.AsOverlappingSRegisterD());
+  EXPECT_TRUE(reg.Equals(Arm64ManagedRegister::FromSRegister(S7)));
+
+  reg = Arm64ManagedRegister::FromSRegister(S31);
+  dreg = Arm64ManagedRegister::FromDRegister(D31);
+  EXPECT_TRUE(!reg.IsNoRegister());
+  EXPECT_TRUE(!reg.IsCoreRegister());
+  EXPECT_TRUE(!reg.IsWRegister());
+  EXPECT_TRUE(reg.IsSRegister());
+  EXPECT_TRUE(!reg.IsDRegister());
+  EXPECT_TRUE(reg.Overlaps(dreg));
+  EXPECT_EQ(S31, reg.AsSRegister());
+  EXPECT_EQ(D31, reg.AsOverlappingSRegisterD());
+  EXPECT_TRUE(reg.Equals(Arm64ManagedRegister::FromSRegister(S31)));
+}
+
+TEST(Arm64ManagedRegister, Equals) {
+  ManagedRegister no_reg = ManagedRegister::NoRegister();
+  EXPECT_TRUE(no_reg.Equals(Arm64ManagedRegister::NoRegister()));
+  EXPECT_TRUE(!no_reg.Equals(Arm64ManagedRegister::FromCoreRegister(X0)));
+  EXPECT_TRUE(!no_reg.Equals(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!no_reg.Equals(Arm64ManagedRegister::FromWRegister(W0)));
+  EXPECT_TRUE(!no_reg.Equals(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(!no_reg.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!no_reg.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+
+  Arm64ManagedRegister reg_X0 = Arm64ManagedRegister::FromCoreRegister(X0);
+  EXPECT_TRUE(!reg_X0.Equals(Arm64ManagedRegister::NoRegister()));
+  EXPECT_TRUE(reg_X0.Equals(Arm64ManagedRegister::FromCoreRegister(X0)));
+  EXPECT_TRUE(!reg_X0.Equals(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg_X0.Equals(Arm64ManagedRegister::FromWRegister(W0)));
+  EXPECT_TRUE(!reg_X0.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg_X0.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+
+  Arm64ManagedRegister reg_X1 = Arm64ManagedRegister::FromCoreRegister(X1);
+  EXPECT_TRUE(!reg_X1.Equals(Arm64ManagedRegister::NoRegister()));
+  EXPECT_TRUE(!reg_X1.Equals(Arm64ManagedRegister::FromCoreRegister(X0)));
+  EXPECT_TRUE(reg_X1.Equals(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg_X1.Equals(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(!reg_X1.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg_X1.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg_X1.Equals(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(!reg_X1.Equals(Arm64ManagedRegister::FromSRegister(S1)));
+
+  Arm64ManagedRegister reg_X31 = Arm64ManagedRegister::FromCoreRegister(X31);
+  EXPECT_TRUE(!reg_X31.Equals(Arm64ManagedRegister::NoRegister()));
+  EXPECT_TRUE(!reg_X31.Equals(Arm64ManagedRegister::FromCoreRegister(SP)));
+  EXPECT_TRUE(reg_X31.Equals(Arm64ManagedRegister::FromCoreRegister(XZR)));
+  EXPECT_TRUE(!reg_X31.Equals(Arm64ManagedRegister::FromWRegister(W31)));
+  EXPECT_TRUE(!reg_X31.Equals(Arm64ManagedRegister::FromWRegister(WZR)));
+  EXPECT_TRUE(!reg_X31.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg_X31.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+
+  Arm64ManagedRegister reg_SP = Arm64ManagedRegister::FromCoreRegister(SP);
+  EXPECT_TRUE(!reg_SP.Equals(Arm64ManagedRegister::NoRegister()));
+  // We expect these to pass - SP has a different semantic than X31/XZR.
+  EXPECT_TRUE(!reg_SP.Equals(Arm64ManagedRegister::FromCoreRegister(X31)));
+  EXPECT_TRUE(!reg_SP.Equals(Arm64ManagedRegister::FromCoreRegister(XZR)));
+  EXPECT_TRUE(!reg_SP.Equals(Arm64ManagedRegister::FromWRegister(W31)));
+  EXPECT_TRUE(!reg_SP.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg_SP.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+
+  Arm64ManagedRegister reg_W8 = Arm64ManagedRegister::FromWRegister(W8);
+  EXPECT_TRUE(!reg_W8.Equals(Arm64ManagedRegister::NoRegister()));
+  EXPECT_TRUE(!reg_W8.Equals(Arm64ManagedRegister::FromCoreRegister(X0)));
+  EXPECT_TRUE(!reg_W8.Equals(Arm64ManagedRegister::FromCoreRegister(X8)));
+  EXPECT_TRUE(reg_W8.Equals(Arm64ManagedRegister::FromWRegister(W8)));
+  EXPECT_TRUE(!reg_W8.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg_W8.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg_W8.Equals(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(!reg_W8.Equals(Arm64ManagedRegister::FromSRegister(S1)));
+
+  Arm64ManagedRegister reg_W12 = Arm64ManagedRegister::FromWRegister(W12);
+  EXPECT_TRUE(!reg_W12.Equals(Arm64ManagedRegister::NoRegister()));
+  EXPECT_TRUE(!reg_W12.Equals(Arm64ManagedRegister::FromCoreRegister(X0)));
+  EXPECT_TRUE(!reg_W12.Equals(Arm64ManagedRegister::FromCoreRegister(X8)));
+  EXPECT_TRUE(reg_W12.Equals(Arm64ManagedRegister::FromWRegister(W12)));
+  EXPECT_TRUE(!reg_W12.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg_W12.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg_W12.Equals(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(!reg_W12.Equals(Arm64ManagedRegister::FromSRegister(S1)));
+
+  Arm64ManagedRegister reg_S0 = Arm64ManagedRegister::FromSRegister(S0);
+  EXPECT_TRUE(!reg_S0.Equals(Arm64ManagedRegister::NoRegister()));
+  EXPECT_TRUE(!reg_S0.Equals(Arm64ManagedRegister::FromCoreRegister(X0)));
+  EXPECT_TRUE(!reg_S0.Equals(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg_S0.Equals(Arm64ManagedRegister::FromWRegister(W0)));
+  EXPECT_TRUE(reg_S0.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg_S0.Equals(Arm64ManagedRegister::FromSRegister(S1)));
+  EXPECT_TRUE(!reg_S0.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg_S0.Equals(Arm64ManagedRegister::FromDRegister(D1)));
+
+  Arm64ManagedRegister reg_S1 = Arm64ManagedRegister::FromSRegister(S1);
+  EXPECT_TRUE(!reg_S1.Equals(Arm64ManagedRegister::NoRegister()));
+  EXPECT_TRUE(!reg_S1.Equals(Arm64ManagedRegister::FromCoreRegister(X0)));
+  EXPECT_TRUE(!reg_S1.Equals(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg_S1.Equals(Arm64ManagedRegister::FromWRegister(W0)));
+  EXPECT_TRUE(!reg_S1.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(reg_S1.Equals(Arm64ManagedRegister::FromSRegister(S1)));
+  EXPECT_TRUE(!reg_S1.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg_S1.Equals(Arm64ManagedRegister::FromDRegister(D1)));
+
+  Arm64ManagedRegister reg_S31 = Arm64ManagedRegister::FromSRegister(S31);
+  EXPECT_TRUE(!reg_S31.Equals(Arm64ManagedRegister::NoRegister()));
+  EXPECT_TRUE(!reg_S31.Equals(Arm64ManagedRegister::FromCoreRegister(X0)));
+  EXPECT_TRUE(!reg_S31.Equals(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg_S31.Equals(Arm64ManagedRegister::FromWRegister(W0)));
+  EXPECT_TRUE(!reg_S31.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(reg_S31.Equals(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg_S31.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg_S31.Equals(Arm64ManagedRegister::FromDRegister(D1)));
+
+  Arm64ManagedRegister reg_D0 = Arm64ManagedRegister::FromDRegister(D0);
+  EXPECT_TRUE(!reg_D0.Equals(Arm64ManagedRegister::NoRegister()));
+  EXPECT_TRUE(!reg_D0.Equals(Arm64ManagedRegister::FromCoreRegister(X0)));
+  EXPECT_TRUE(!reg_D0.Equals(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(!reg_D0.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg_D0.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg_D0.Equals(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(reg_D0.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg_D0.Equals(Arm64ManagedRegister::FromDRegister(D1)));
+
+  Arm64ManagedRegister reg_D15 = Arm64ManagedRegister::FromDRegister(D15);
+  EXPECT_TRUE(!reg_D15.Equals(Arm64ManagedRegister::NoRegister()));
+  EXPECT_TRUE(!reg_D15.Equals(Arm64ManagedRegister::FromCoreRegister(X0)));
+  EXPECT_TRUE(!reg_D15.Equals(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg_D15.Equals(Arm64ManagedRegister::FromWRegister(W0)));
+  EXPECT_TRUE(!reg_D15.Equals(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg_D15.Equals(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg_D15.Equals(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg_D15.Equals(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(reg_D15.Equals(Arm64ManagedRegister::FromDRegister(D15)));
+}
+
+TEST(Arm64ManagedRegister, Overlaps) {
+  Arm64ManagedRegister reg = Arm64ManagedRegister::FromCoreRegister(X0);
+  Arm64ManagedRegister reg_o = Arm64ManagedRegister::FromWRegister(W0);
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(SP)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromWRegister(W0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W12)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(WZR)));
+  EXPECT_EQ(X0, reg_o.AsOverlappingWRegisterCore());
+  EXPECT_EQ(W0, reg.AsOverlappingCoreRegisterLow());
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S30)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D7)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D15)));
+
+  reg = Arm64ManagedRegister::FromCoreRegister(X10);
+  reg_o = Arm64ManagedRegister::FromWRegister(W10);
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X10)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(SP)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromWRegister(W10)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W12)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(WZR)));
+  EXPECT_EQ(X10, reg_o.AsOverlappingWRegisterCore());
+  EXPECT_EQ(W10, reg.AsOverlappingCoreRegisterLow());
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S30)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D7)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D15)));
+
+  reg = Arm64ManagedRegister::FromCoreRegister(IP1);
+  reg_o = Arm64ManagedRegister::FromWRegister(W17);
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X17)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(SP)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromWRegister(W17)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W12)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(WZR)));
+  EXPECT_EQ(X17, reg_o.AsOverlappingWRegisterCore());
+  EXPECT_EQ(W17, reg.AsOverlappingCoreRegisterLow());
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S30)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D7)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D15)));
+
+  reg = Arm64ManagedRegister::FromCoreRegister(XZR);
+  reg_o = Arm64ManagedRegister::FromWRegister(WZR);
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(SP)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromWRegister(W31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W12)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W19)));
+  EXPECT_EQ(X31, reg_o.AsOverlappingWRegisterCore());
+  EXPECT_EQ(W31, reg.AsOverlappingCoreRegisterLow());
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S30)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D7)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D15)));
+
+  reg = Arm64ManagedRegister::FromCoreRegister(SP);
+  reg_o = Arm64ManagedRegister::FromWRegister(WZR);
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X15)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromWRegister(WZR)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W12)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromWRegister(W31)));
+  EXPECT_EQ(X31, reg_o.AsOverlappingWRegisterCore());
+  EXPECT_EQ(W31, reg.AsOverlappingCoreRegisterLow());
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S30)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D7)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D15)));
+
+  reg = Arm64ManagedRegister::FromWRegister(W1);
+  reg_o = Arm64ManagedRegister::FromCoreRegister(X1);
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(WZR)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W12)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W31)));
+  EXPECT_EQ(W1, reg_o.AsOverlappingCoreRegisterLow());
+  EXPECT_EQ(X1, reg.AsOverlappingWRegisterCore());
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S30)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D7)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D15)));
+
+  reg = Arm64ManagedRegister::FromWRegister(W21);
+  reg_o = Arm64ManagedRegister::FromCoreRegister(X21);
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromWRegister(W21)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X21)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(WZR)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W12)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W31)));
+  EXPECT_EQ(W21, reg_o.AsOverlappingCoreRegisterLow());
+  EXPECT_EQ(X21, reg.AsOverlappingWRegisterCore());
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S30)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D7)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D15)));
+
+
+  reg = Arm64ManagedRegister::FromSRegister(S1);
+  reg_o = Arm64ManagedRegister::FromDRegister(D1);
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(WZR)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W12)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W31)));
+  EXPECT_EQ(S1, reg_o.AsOverlappingDRegisterLow());
+  EXPECT_EQ(D1, reg.AsOverlappingSRegisterD());
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromSRegister(S1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S30)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D0)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromDRegister(D1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D7)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D15)));
+
+  reg = Arm64ManagedRegister::FromSRegister(S15);
+  reg_o = Arm64ManagedRegister::FromDRegister(D15);
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(WZR)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W12)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W31)));
+  EXPECT_EQ(S15, reg_o.AsOverlappingDRegisterLow());
+  EXPECT_EQ(D15, reg.AsOverlappingSRegisterD());
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromSRegister(S15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S17)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S16)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D16)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromDRegister(D15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D17)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D20)));
+
+  reg = Arm64ManagedRegister::FromDRegister(D15);
+  reg_o = Arm64ManagedRegister::FromSRegister(S15);
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromCoreRegister(X15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(WZR)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W1)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W12)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromWRegister(W31)));
+  EXPECT_EQ(S15, reg.AsOverlappingDRegisterLow());
+  EXPECT_EQ(D15, reg_o.AsOverlappingSRegisterD());
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S0)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromSRegister(S15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S17)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S16)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromSRegister(S31)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D16)));
+  EXPECT_TRUE(reg.Overlaps(Arm64ManagedRegister::FromDRegister(D15)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D2)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D17)));
+  EXPECT_TRUE(!reg.Overlaps(Arm64ManagedRegister::FromDRegister(D20)));
+}
+
+}  // namespace arm64
+}  // namespace art