Initial revision of ARM assembler.

runtime/vm/assembler_arm.cc

Index: runtime/vm/assembler_arm.cc
===================================================================
--- runtime/vm/assembler_arm.cc	(revision 17773)
+++ runtime/vm/assembler_arm.cc	(working copy)
@@ -10,9 +10,1490 @@
 namespace dart {
 
 DEFINE_FLAG(bool, print_stop_message, true, "Print stop message.");
-DEFINE_FLAG(bool, code_comments, false,
-            "Include comments into code and disassembly");
 
+
+// Instruction encoding bits.
+enum {
+  H   = 1 << 5,   // halfword (or byte)
+  L   = 1 << 20,  // load (or store)
+  S   = 1 << 20,  // set condition code (or leave unchanged)
+  W   = 1 << 21,  // writeback base register (or leave unchanged)
+  A   = 1 << 21,  // accumulate in multiply instruction (or not)
+  B   = 1 << 22,  // unsigned byte (or word)
+  N   = 1 << 22,  // long (or short)
+  U   = 1 << 23,  // positive (or negative) offset/index
+  P   = 1 << 24,  // offset/pre-indexed addressing (or post-indexed addressing)
+  I   = 1 << 25,  // immediate shifter operand (or not)
+
+  B0 = 1,
+  B1 = 1 << 1,
+  B2 = 1 << 2,
+  B3 = 1 << 3,
+  B4 = 1 << 4,
+  B5 = 1 << 5,
+  B6 = 1 << 6,
+  B7 = 1 << 7,
+  B8 = 1 << 8,
+  B9 = 1 << 9,
+  B10 = 1 << 10,
+  B11 = 1 << 11,
+  B12 = 1 << 12,
+  B16 = 1 << 16,
+  B17 = 1 << 17,
+  B18 = 1 << 18,
+  B19 = 1 << 19,
+  B20 = 1 << 20,
+  B21 = 1 << 21,
+  B22 = 1 << 22,
+  B23 = 1 << 23,
+  B24 = 1 << 24,
+  B25 = 1 << 25,
+  B26 = 1 << 26,
+  B27 = 1 << 27,
+
+  // ldrex/strex register field encodings.
+  kLdExRnShift = 16,
+  kLdExRtShift = 12,
+  kStrExRnShift = 16,
+  kStrExRdShift = 12,
+  kStrExRtShift = 0,
+};
+
+
+uint32_t Address::encoding3() const {
+  const uint32_t offset_mask = (1 << 12) - 1;
+  uint32_t offset = encoding_ & offset_mask;
+  ASSERT(offset < 256);
+  return (encoding_ & ~offset_mask) | ((offset & 0xf0) << 4) | (offset & 0xf);
+}
+
+
+uint32_t Address::vencoding() const {
+  const uint32_t offset_mask = (1 << 12) - 1;
+  uint32_t offset = encoding_ & offset_mask;
+  ASSERT(offset < (1 << 10));  // In the range 0 to +1020.
+  ASSERT(Utils::Utils::IsAligned(offset, 2));  // Multiple of 4.
+  int mode = encoding_ & ((8|4|1) << 21);
+  ASSERT((mode == Offset) || (mode == NegOffset));
+  uint32_t vencoding = (encoding_ & (0xf << kRnShift)) | (offset >> 2);
+  if (mode == Offset) {
+    vencoding |= 1 << 23;
+  }
+  return vencoding;
+}
+
+
+void Assembler::Emit(int32_t value) {
+  AssemblerBuffer::EnsureCapacity ensured(&buffer_);
+  buffer_.Emit<int32_t>(value);
+}
+
+
+void Assembler::EmitType01(Condition cond,
+                           int type,
+                           Opcode opcode,
+                           int set_cc,
+                           Register rn,
+                           Register rd,
+                           ShifterOperand so) {
+  ASSERT(rd != kNoRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = static_cast<int32_t>(cond) << kConditionShift |
+                     type << kTypeShift |
+                     static_cast<int32_t>(opcode) << kOpcodeShift |
+                     set_cc << kSShift |
+                     static_cast<int32_t>(rn) << kRnShift |
+                     static_cast<int32_t>(rd) << kRdShift |
+                     so.encoding();
+  Emit(encoding);
+}
+
+
+void Assembler::EmitType5(Condition cond, int offset, bool link) {
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = static_cast<int32_t>(cond) << kConditionShift |
+                     5 << kTypeShift |
+                     (link ? 1 : 0) << kLinkShift;
+  Emit(Assembler::EncodeBranchOffset(offset, encoding));
+}
+
+
+void Assembler::EmitMemOp(Condition cond,
+                          bool load,
+                          bool byte,
+                          Register rd,
+                          Address ad) {
+  ASSERT(rd != kNoRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B26 |
+                     (load ? L : 0) |
+                     (byte ? B : 0) |
+                     (static_cast<int32_t>(rd) << kRdShift) |
+                     ad.encoding();
+  Emit(encoding);
+}
+
+
+void Assembler::EmitMemOpAddressMode3(Condition cond,
+                                      int32_t mode,
+                                      Register rd,
+                                      Address ad) {
+  ASSERT(rd != kNoRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B22  |
+                     mode |
+                     (static_cast<int32_t>(rd) << kRdShift) |
+                     ad.encoding3();
+  Emit(encoding);
+}
+
+
+void Assembler::EmitMultiMemOp(Condition cond,
+                               BlockAddressMode am,
+                               bool load,
+                               Register base,
+                               RegList regs) {
+  ASSERT(base != kNoRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 |
+                     am |
+                     (load ? L : 0) |
+                     (static_cast<int32_t>(base) << kRnShift) |
+                     regs;
+  Emit(encoding);
+}
+
+
+void Assembler::EmitShiftImmediate(Condition cond,
+                                   Shift opcode,
+                                   Register rd,
+                                   Register rm,
+                                   ShifterOperand so) {
+  ASSERT(cond != kNoCondition);
+  ASSERT(so.type() == 1);
+  int32_t encoding = static_cast<int32_t>(cond) << kConditionShift |
+                     static_cast<int32_t>(MOV) << kOpcodeShift |
+                     static_cast<int32_t>(rd) << kRdShift |
+                     so.encoding() << kShiftImmShift |
+                     static_cast<int32_t>(opcode) << kShiftShift |
+                     static_cast<int32_t>(rm);
+  Emit(encoding);
+}
+
+
+void Assembler::EmitShiftRegister(Condition cond,
+                                  Shift opcode,
+                                  Register rd,
+                                  Register rm,
+                                  ShifterOperand so) {
+  ASSERT(cond != kNoCondition);
+  ASSERT(so.type() == 0);
+  int32_t encoding = static_cast<int32_t>(cond) << kConditionShift |
+                     static_cast<int32_t>(MOV) << kOpcodeShift |
+                     static_cast<int32_t>(rd) << kRdShift |
+                     so.encoding() << kShiftRegisterShift |
+                     static_cast<int32_t>(opcode) << kShiftShift |
+                     B4 |
+                     static_cast<int32_t>(rm);
+  Emit(encoding);
+}
+
+
+void Assembler::EmitBranch(Condition cond, Label* label, bool link) {
+  if (label->IsBound()) {
+    EmitType5(cond, label->Position() - buffer_.Size(), link);
+  } else {
+    int position = buffer_.Size();
+    // Use the offset field of the branch instruction for linking the sites.
+    EmitType5(cond, label->position_, link);
+    label->LinkTo(position);
+  }
+}
+
+
+void Assembler::and_(Register rd, Register rn, ShifterOperand so,
+                     Condition cond) {
+  EmitType01(cond, so.type(), AND, 0, rn, rd, so);
+}
+
+
+void Assembler::eor(Register rd, Register rn, ShifterOperand so,
+                    Condition cond) {
+  EmitType01(cond, so.type(), EOR, 0, rn, rd, so);
+}
+
+
+void Assembler::sub(Register rd, Register rn, ShifterOperand so,
+                    Condition cond) {
+  EmitType01(cond, so.type(), SUB, 0, rn, rd, so);
+}
+
+void Assembler::rsb(Register rd, Register rn, ShifterOperand so,
+                    Condition cond) {
+  EmitType01(cond, so.type(), RSB, 0, rn, rd, so);
+}
+
+void Assembler::rsbs(Register rd, Register rn, ShifterOperand so,
+                     Condition cond) {
+  EmitType01(cond, so.type(), RSB, 1, rn, rd, so);
+}
+
+
+void Assembler::add(Register rd, Register rn, ShifterOperand so,
+                    Condition cond) {
+  EmitType01(cond, so.type(), ADD, 0, rn, rd, so);
+}
+
+
+void Assembler::adds(Register rd, Register rn, ShifterOperand so,
+                     Condition cond) {
+  EmitType01(cond, so.type(), ADD, 1, rn, rd, so);
+}
+
+
+void Assembler::subs(Register rd, Register rn, ShifterOperand so,
+                     Condition cond) {
+  EmitType01(cond, so.type(), SUB, 1, rn, rd, so);
+}
+
+
+void Assembler::adc(Register rd, Register rn, ShifterOperand so,
+                    Condition cond) {
+  EmitType01(cond, so.type(), ADC, 0, rn, rd, so);
+}
+
+
+void Assembler::sbc(Register rd, Register rn, ShifterOperand so,
+                    Condition cond) {
+  EmitType01(cond, so.type(), SBC, 0, rn, rd, so);
+}
+
+
+void Assembler::rsc(Register rd, Register rn, ShifterOperand so,
+                    Condition cond) {
+  EmitType01(cond, so.type(), RSC, 0, rn, rd, so);
+}
+
+
+void Assembler::tst(Register rn, ShifterOperand so, Condition cond) {
+  EmitType01(cond, so.type(), TST, 1, rn, R0, so);
+}
+
+
+void Assembler::teq(Register rn, ShifterOperand so, Condition cond) {
+  EmitType01(cond, so.type(), TEQ, 1, rn, R0, so);
+}
+
+
+void Assembler::cmp(Register rn, ShifterOperand so, Condition cond) {
+  EmitType01(cond, so.type(), CMP, 1, rn, R0, so);
+}
+
+
+void Assembler::cmn(Register rn, ShifterOperand so, Condition cond) {
+  EmitType01(cond, so.type(), CMN, 1, rn, R0, so);
+}
+
+
+void Assembler::orr(Register rd, Register rn, ShifterOperand so,
+                    Condition cond) {
+  EmitType01(cond, so.type(), ORR, 0, rn, rd, so);
+}
+
+
+void Assembler::orrs(Register rd, Register rn, ShifterOperand so,
+                     Condition cond) {
+  EmitType01(cond, so.type(), ORR, 1, rn, rd, so);
+}
+
+
+void Assembler::mov(Register rd, ShifterOperand so, Condition cond) {
+  EmitType01(cond, so.type(), MOV, 0, R0, rd, so);
+}
+
+
+void Assembler::movs(Register rd, ShifterOperand so, Condition cond) {
+  EmitType01(cond, so.type(), MOV, 1, R0, rd, so);
+}
+
+
+void Assembler::bic(Register rd, Register rn, ShifterOperand so,
+                    Condition cond) {
+  EmitType01(cond, so.type(), BIC, 0, rn, rd, so);
+}
+
+
+void Assembler::mvn(Register rd, ShifterOperand so, Condition cond) {
+  EmitType01(cond, so.type(), MVN, 0, R0, rd, so);
+}
+
+
+void Assembler::mvns(Register rd, ShifterOperand so, Condition cond) {
+  EmitType01(cond, so.type(), MVN, 1, R0, rd, so);
+}
+
+
+void Assembler::clz(Register rd, Register rm, Condition cond) {
+  ASSERT(rd != kNoRegister);
+  ASSERT(rm != kNoRegister);
+  ASSERT(cond != kNoCondition);
+  ASSERT(rd != PC);
+  ASSERT(rm != PC);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B24 | B22 | B21 | (0xf << 16) |
+                     (static_cast<int32_t>(rd) << kRdShift) |
+                     (0xf << 8) | B4 | static_cast<int32_t>(rm);
+  Emit(encoding);
+}
+
+
+void Assembler::movw(Register rd, uint16_t imm16, Condition cond) {
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = static_cast<int32_t>(cond) << kConditionShift |
+                     B25 | B24 | ((imm16 >> 12) << 16) |
+                     static_cast<int32_t>(rd) << kRdShift | (imm16 & 0xfff);
+  Emit(encoding);
+}
+
+
+void Assembler::movt(Register rd, uint16_t imm16, Condition cond) {
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = static_cast<int32_t>(cond) << kConditionShift |
+                     B25 | B24 | B22 | ((imm16 >> 12) << 16) |
+                     static_cast<int32_t>(rd) << kRdShift | (imm16 & 0xfff);
+  Emit(encoding);
+}
+
+
+void Assembler::EmitMulOp(Condition cond, int32_t opcode,
+                          Register rd, Register rn,
+                          Register rm, Register rs) {
+  ASSERT(rd != kNoRegister);
+  ASSERT(rn != kNoRegister);
+  ASSERT(rm != kNoRegister);
+  ASSERT(rs != kNoRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = opcode |
+      (static_cast<int32_t>(cond) << kConditionShift) |
+      (static_cast<int32_t>(rn) << kRnShift) |
+      (static_cast<int32_t>(rd) << kRdShift) |
+      (static_cast<int32_t>(rs) << kRsShift) |
+      B7 | B4 |
+      (static_cast<int32_t>(rm) << kRmShift);
+  Emit(encoding);
+}
+
+
+void Assembler::mul(Register rd, Register rn,
+                    Register rm, Condition cond) {
+  // Assembler registers rd, rn, rm are encoded as rn, rm, rs.
+  EmitMulOp(cond, 0, R0, rd, rn, rm);
+}
+
+
+void Assembler::mla(Register rd, Register rn,
+                    Register rm, Register ra, Condition cond) {
+  // Assembler registers rd, rn, rm, ra are encoded as rn, rm, rs, rd.
+  EmitMulOp(cond, B21, ra, rd, rn, rm);
+}
+
+
+void Assembler::mls(Register rd, Register rn,
+                    Register rm, Register ra, Condition cond) {
+  // Assembler registers rd, rn, rm, ra are encoded as rn, rm, rs, rd.
+  EmitMulOp(cond, B22 | B21, ra, rd, rn, rm);
+}
+
+
+void Assembler::umull(Register rd_lo, Register rd_hi,
+                      Register rn, Register rm, Condition cond) {
+  // Assembler registers rd_lo, rd_hi, rn, rm are encoded as rd, rn, rm, rs.
+  EmitMulOp(cond, B23, rd_lo, rd_hi, rn, rm);
+}
+
+
+void Assembler::ldr(Register rd, Address ad, Condition cond) {
+  EmitMemOp(cond, true, false, rd, ad);
+}
+
+
+void Assembler::str(Register rd, Address ad, Condition cond) {
+  EmitMemOp(cond, false, false, rd, ad);
+}
+
+
+void Assembler::ldrb(Register rd, Address ad, Condition cond) {
+  EmitMemOp(cond, true, true, rd, ad);
+}
+
+
+void Assembler::strb(Register rd, Address ad, Condition cond) {
+  EmitMemOp(cond, false, true, rd, ad);
+}
+
+
+void Assembler::ldrh(Register rd, Address ad, Condition cond) {
+  EmitMemOpAddressMode3(cond, L | B7 | H | B4, rd, ad);
+}
+
+
+void Assembler::strh(Register rd, Address ad, Condition cond) {
+  EmitMemOpAddressMode3(cond, B7 | H | B4, rd, ad);
+}
+
+
+void Assembler::ldrsb(Register rd, Address ad, Condition cond) {
+  EmitMemOpAddressMode3(cond, L | B7 | B6 | B4, rd, ad);
+}
+
+
+void Assembler::ldrsh(Register rd, Address ad, Condition cond) {
+  EmitMemOpAddressMode3(cond, L | B7 | B6 | H | B4, rd, ad);
+}
+
+
+void Assembler::ldrd(Register rd, Address ad, Condition cond) {
+  ASSERT((rd % 2) == 0);
+  EmitMemOpAddressMode3(cond, B7 | B6 | B4, rd, ad);
+}
+
+
+void Assembler::strd(Register rd, Address ad, Condition cond) {
+  ASSERT((rd % 2) == 0);
+  EmitMemOpAddressMode3(cond, B7 | B6 | B5 | B4, rd, ad);
+}
+
+
+void Assembler::ldm(BlockAddressMode am, Register base, RegList regs,
+                    Condition cond) {
+  EmitMultiMemOp(cond, am, true, base, regs);
+}
+
+
+void Assembler::stm(BlockAddressMode am, Register base, RegList regs,
+                    Condition cond) {
+  EmitMultiMemOp(cond, am, false, base, regs);
+}
+
+
+void Assembler::ldrex(Register rt, Register rn, Condition cond) {
+  ASSERT(rn != kNoRegister);
+  ASSERT(rt != kNoRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B24 |
+                     B23 |
+                     L   |
+                     (static_cast<int32_t>(rn) << kLdExRnShift) |
+                     (static_cast<int32_t>(rt) << kLdExRtShift) |
+                     B11 | B10 | B9 | B8 | B7 | B4 | B3 | B2 | B1 | B0;
+  Emit(encoding);
+}
+
+
+void Assembler::strex(Register rd, Register rt, Register rn, Condition cond) {
+  ASSERT(rn != kNoRegister);
+  ASSERT(rd != kNoRegister);
+  ASSERT(rt != kNoRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B24 |
+                     B23 |
+                     (static_cast<int32_t>(rn) << kStrExRnShift) |
+                     (static_cast<int32_t>(rd) << kStrExRdShift) |
+                     B11 | B10 | B9 | B8 | B7 | B4 |
+                     (static_cast<int32_t>(rt) << kStrExRtShift);
+  Emit(encoding);
+}
+
+
+void Assembler::clrex() {
+  int32_t encoding = (kSpecialCondition << kConditionShift) |
+                     B26 | B24 | B22 | B21 | B20 | (0xff << 12) | B4 | 0xf;
+  Emit(encoding);
+}
+
+
+void Assembler::nop(Condition cond) {
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B25 | B24 | B21 | (0xf << 12);
+  Emit(encoding);
+}
+
+
+void Assembler::vmovsr(SRegister sn, Register rt, Condition cond) {
+  ASSERT(sn != kNoSRegister);
+  ASSERT(rt != kNoRegister);
+  ASSERT(rt != SP);
+  ASSERT(rt != PC);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B25 |
+                     ((static_cast<int32_t>(sn) >> 1)*B16) |
+                     (static_cast<int32_t>(rt)*B12) | B11 | B9 |
+                     ((static_cast<int32_t>(sn) & 1)*B7) | B4;
+  Emit(encoding);
+}
+
+
+void Assembler::vmovrs(Register rt, SRegister sn, Condition cond) {
+  ASSERT(sn != kNoSRegister);
+  ASSERT(rt != kNoRegister);
+  ASSERT(rt != SP);
+  ASSERT(rt != PC);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B25 | B20 |
+                     ((static_cast<int32_t>(sn) >> 1)*B16) |
+                     (static_cast<int32_t>(rt)*B12) | B11 | B9 |
+                     ((static_cast<int32_t>(sn) & 1)*B7) | B4;
+  Emit(encoding);
+}
+
+
+void Assembler::vmovsrr(SRegister sm, Register rt, Register rt2,
+                        Condition cond) {
+  ASSERT(sm != kNoSRegister);
+  ASSERT(sm != S31);
+  ASSERT(rt != kNoRegister);
+  ASSERT(rt != SP);
+  ASSERT(rt != PC);
+  ASSERT(rt2 != kNoRegister);
+  ASSERT(rt2 != SP);
+  ASSERT(rt2 != PC);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B22 |
+                     (static_cast<int32_t>(rt2)*B16) |
+                     (static_cast<int32_t>(rt)*B12) | B11 | B9 |
+                     ((static_cast<int32_t>(sm) & 1)*B5) | B4 |
+                     (static_cast<int32_t>(sm) >> 1);
+  Emit(encoding);
+}
+
+
+void Assembler::vmovrrs(Register rt, Register rt2, SRegister sm,
+                        Condition cond) {
+  ASSERT(sm != kNoSRegister);
+  ASSERT(sm != S31);
+  ASSERT(rt != kNoRegister);
+  ASSERT(rt != SP);
+  ASSERT(rt != PC);
+  ASSERT(rt2 != kNoRegister);
+  ASSERT(rt2 != SP);
+  ASSERT(rt2 != PC);
+  ASSERT(rt != rt2);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B22 | B20 |
+                     (static_cast<int32_t>(rt2)*B16) |
+                     (static_cast<int32_t>(rt)*B12) | B11 | B9 |
+                     ((static_cast<int32_t>(sm) & 1)*B5) | B4 |
+                     (static_cast<int32_t>(sm) >> 1);
+  Emit(encoding);
+}
+
+
+void Assembler::vmovdrr(DRegister dm, Register rt, Register rt2,
+                        Condition cond) {
+  ASSERT(dm != kNoDRegister);
+  ASSERT(rt != kNoRegister);
+  ASSERT(rt != SP);
+  ASSERT(rt != PC);
+  ASSERT(rt2 != kNoRegister);
+  ASSERT(rt2 != SP);
+  ASSERT(rt2 != PC);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B22 |
+                     (static_cast<int32_t>(rt2)*B16) |
+                     (static_cast<int32_t>(rt)*B12) | B11 | B9 | B8 |
+                     ((static_cast<int32_t>(dm) >> 4)*B5) | B4 |
+                     (static_cast<int32_t>(dm) & 0xf);
+  Emit(encoding);
+}
+
+
+void Assembler::vmovrrd(Register rt, Register rt2, DRegister dm,
+                        Condition cond) {
+  ASSERT(dm != kNoDRegister);
+  ASSERT(rt != kNoRegister);
+  ASSERT(rt != SP);
+  ASSERT(rt != PC);
+  ASSERT(rt2 != kNoRegister);
+  ASSERT(rt2 != SP);
+  ASSERT(rt2 != PC);
+  ASSERT(rt != rt2);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B22 | B20 |
+                     (static_cast<int32_t>(rt2)*B16) |
+                     (static_cast<int32_t>(rt)*B12) | B11 | B9 | B8 |
+                     ((static_cast<int32_t>(dm) >> 4)*B5) | B4 |
+                     (static_cast<int32_t>(dm) & 0xf);
+  Emit(encoding);
+}
+
+
+void Assembler::vldrs(SRegister sd, Address ad, Condition cond) {
+  ASSERT(sd != kNoSRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B24 | B20 |
+                     ((static_cast<int32_t>(sd) & 1)*B22) |
+                     ((static_cast<int32_t>(sd) >> 1)*B12) |
+                     B11 | B9 | ad.vencoding();
+  Emit(encoding);
+}
+
+
+void Assembler::vstrs(SRegister sd, Address ad, Condition cond) {
+  ASSERT(static_cast<Register>(ad.encoding_ & (0xf << kRnShift)) != PC);
+  ASSERT(sd != kNoSRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B24 |
+                     ((static_cast<int32_t>(sd) & 1)*B22) |
+                     ((static_cast<int32_t>(sd) >> 1)*B12) |
+                     B11 | B9 | ad.vencoding();
+  Emit(encoding);
+}
+
+
+void Assembler::vldrd(DRegister dd, Address ad, Condition cond) {
+  ASSERT(dd != kNoDRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B24 | B20 |
+                     ((static_cast<int32_t>(dd) >> 4)*B22) |
+                     ((static_cast<int32_t>(dd) & 0xf)*B12) |
+                     B11 | B9 | B8 | ad.vencoding();
+  Emit(encoding);
+}
+
+
+void Assembler::vstrd(DRegister dd, Address ad, Condition cond) {
+  ASSERT(static_cast<Register>(ad.encoding_ & (0xf << kRnShift)) != PC);
+  ASSERT(dd != kNoDRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B24 |
+                     ((static_cast<int32_t>(dd) >> 4)*B22) |
+                     ((static_cast<int32_t>(dd) & 0xf)*B12) |
+                     B11 | B9 | B8 | ad.vencoding();
+  Emit(encoding);
+}
+
+
+void Assembler::EmitVFPsss(Condition cond, int32_t opcode,
+                           SRegister sd, SRegister sn, SRegister sm) {
+  ASSERT(sd != kNoSRegister);
+  ASSERT(sn != kNoSRegister);
+  ASSERT(sm != kNoSRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B25 | B11 | B9 | opcode |
+                     ((static_cast<int32_t>(sd) & 1)*B22) |
+                     ((static_cast<int32_t>(sn) >> 1)*B16) |
+                     ((static_cast<int32_t>(sd) >> 1)*B12) |
+                     ((static_cast<int32_t>(sn) & 1)*B7) |
+                     ((static_cast<int32_t>(sm) & 1)*B5) |
+                     (static_cast<int32_t>(sm) >> 1);
+  Emit(encoding);
+}
+
+
+void Assembler::EmitVFPddd(Condition cond, int32_t opcode,
+                           DRegister dd, DRegister dn, DRegister dm) {
+  ASSERT(dd != kNoDRegister);
+  ASSERT(dn != kNoDRegister);
+  ASSERT(dm != kNoDRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B25 | B11 | B9 | B8 | opcode |
+                     ((static_cast<int32_t>(dd) >> 4)*B22) |
+                     ((static_cast<int32_t>(dn) & 0xf)*B16) |
+                     ((static_cast<int32_t>(dd) & 0xf)*B12) |
+                     ((static_cast<int32_t>(dn) >> 4)*B7) |
+                     ((static_cast<int32_t>(dm) >> 4)*B5) |
+                     (static_cast<int32_t>(dm) & 0xf);
+  Emit(encoding);
+}
+
+
+void Assembler::vmovs(SRegister sd, SRegister sm, Condition cond) {
+  EmitVFPsss(cond, B23 | B21 | B20 | B6, sd, S0, sm);
+}
+
+
+void Assembler::vmovd(DRegister dd, DRegister dm, Condition cond) {
+  EmitVFPddd(cond, B23 | B21 | B20 | B6, dd, D0, dm);
+}
+
+
+bool Assembler::vmovs(SRegister sd, float s_imm, Condition cond) {
+  uint32_t imm32 = bit_cast<uint32_t, float>(s_imm);
+  if (((imm32 & ((1 << 19) - 1)) == 0) &&
+      ((((imm32 >> 25) & ((1 << 6) - 1)) == (1 << 5)) ||
+       (((imm32 >> 25) & ((1 << 6) - 1)) == ((1 << 5) -1)))) {
+    uint8_t imm8 = ((imm32 >> 31) << 7) | (((imm32 >> 29) & 1) << 6) |
+        ((imm32 >> 19) & ((1 << 6) -1));
+    EmitVFPsss(cond, B23 | B21 | B20 | ((imm8 >> 4)*B16) | (imm8 & 0xf),
+               sd, S0, S0);
+    return true;
+  }
+  return false;
+}
+
+
+bool Assembler::vmovd(DRegister dd, double d_imm, Condition cond) {
+  uint64_t imm64 = bit_cast<uint64_t, double>(d_imm);
+  if (((imm64 & ((1LL << 48) - 1)) == 0) &&
+      ((((imm64 >> 54) & ((1 << 9) - 1)) == (1 << 8)) ||
+       (((imm64 >> 54) & ((1 << 9) - 1)) == ((1 << 8) -1)))) {
+    uint8_t imm8 = ((imm64 >> 63) << 7) | (((imm64 >> 61) & 1) << 6) |
+        ((imm64 >> 48) & ((1 << 6) -1));
+    EmitVFPddd(cond, B23 | B21 | B20 | ((imm8 >> 4)*B16) | B8 | (imm8 & 0xf),
+               dd, D0, D0);
+    return true;
+  }
+  return false;
+}
+
+
+void Assembler::vadds(SRegister sd, SRegister sn, SRegister sm,
+                      Condition cond) {
+  EmitVFPsss(cond, B21 | B20, sd, sn, sm);
+}
+
+
+void Assembler::vaddd(DRegister dd, DRegister dn, DRegister dm,
+                      Condition cond) {
+  EmitVFPddd(cond, B21 | B20, dd, dn, dm);
+}
+
+
+void Assembler::vsubs(SRegister sd, SRegister sn, SRegister sm,
+                      Condition cond) {
+  EmitVFPsss(cond, B21 | B20 | B6, sd, sn, sm);
+}
+
+
+void Assembler::vsubd(DRegister dd, DRegister dn, DRegister dm,
+                      Condition cond) {
+  EmitVFPddd(cond, B21 | B20 | B6, dd, dn, dm);
+}
+
+
+void Assembler::vmuls(SRegister sd, SRegister sn, SRegister sm,
+                      Condition cond) {
+  EmitVFPsss(cond, B21, sd, sn, sm);
+}
+
+
+void Assembler::vmuld(DRegister dd, DRegister dn, DRegister dm,
+                      Condition cond) {
+  EmitVFPddd(cond, B21, dd, dn, dm);
+}
+
+
+void Assembler::vmlas(SRegister sd, SRegister sn, SRegister sm,
+                      Condition cond) {
+  EmitVFPsss(cond, 0, sd, sn, sm);
+}
+
+
+void Assembler::vmlad(DRegister dd, DRegister dn, DRegister dm,
+                      Condition cond) {
+  EmitVFPddd(cond, 0, dd, dn, dm);
+}
+
+
+void Assembler::vmlss(SRegister sd, SRegister sn, SRegister sm,
+                      Condition cond) {
+  EmitVFPsss(cond, B6, sd, sn, sm);
+}
+
+
+void Assembler::vmlsd(DRegister dd, DRegister dn, DRegister dm,
+                      Condition cond) {
+  EmitVFPddd(cond, B6, dd, dn, dm);
+}
+
+
+void Assembler::vdivs(SRegister sd, SRegister sn, SRegister sm,
+                      Condition cond) {
+  EmitVFPsss(cond, B23, sd, sn, sm);
+}
+
+
+void Assembler::vdivd(DRegister dd, DRegister dn, DRegister dm,
+                      Condition cond) {
+  EmitVFPddd(cond, B23, dd, dn, dm);
+}
+
+
+void Assembler::vabss(SRegister sd, SRegister sm, Condition cond) {
+  EmitVFPsss(cond, B23 | B21 | B20 | B7 | B6, sd, S0, sm);
+}
+
+
+void Assembler::vabsd(DRegister dd, DRegister dm, Condition cond) {
+  EmitVFPddd(cond, B23 | B21 | B20 | B7 | B6, dd, D0, dm);
+}
+
+
+void Assembler::vnegs(SRegister sd, SRegister sm, Condition cond) {
+  EmitVFPsss(cond, B23 | B21 | B20 | B16 | B6, sd, S0, sm);
+}
+
+
+void Assembler::vnegd(DRegister dd, DRegister dm, Condition cond) {
+  EmitVFPddd(cond, B23 | B21 | B20 | B16 | B6, dd, D0, dm);
+}
+
+
+void Assembler::vsqrts(SRegister sd, SRegister sm, Condition cond) {
+  EmitVFPsss(cond, B23 | B21 | B20 | B16 | B7 | B6, sd, S0, sm);
+}
+
+void Assembler::vsqrtd(DRegister dd, DRegister dm, Condition cond) {
+  EmitVFPddd(cond, B23 | B21 | B20 | B16 | B7 | B6, dd, D0, dm);
+}
+
+
+void Assembler::EmitVFPsd(Condition cond, int32_t opcode,
+                          SRegister sd, DRegister dm) {
+  ASSERT(sd != kNoSRegister);
+  ASSERT(dm != kNoDRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B25 | B11 | B9 | opcode |
+                     ((static_cast<int32_t>(sd) & 1)*B22) |
+                     ((static_cast<int32_t>(sd) >> 1)*B12) |
+                     ((static_cast<int32_t>(dm) >> 4)*B5) |
+                     (static_cast<int32_t>(dm) & 0xf);
+  Emit(encoding);
+}
+
+
+void Assembler::EmitVFPds(Condition cond, int32_t opcode,
+                          DRegister dd, SRegister sm) {
+  ASSERT(dd != kNoDRegister);
+  ASSERT(sm != kNoSRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B25 | B11 | B9 | opcode |
+                     ((static_cast<int32_t>(dd) >> 4)*B22) |
+                     ((static_cast<int32_t>(dd) & 0xf)*B12) |
+                     ((static_cast<int32_t>(sm) & 1)*B5) |
+                     (static_cast<int32_t>(sm) >> 1);
+  Emit(encoding);
+}
+
+
+void Assembler::vcvtsd(SRegister sd, DRegister dm, Condition cond) {
+  EmitVFPsd(cond, B23 | B21 | B20 | B18 | B17 | B16 | B8 | B7 | B6, sd, dm);
+}
+
+
+void Assembler::vcvtds(DRegister dd, SRegister sm, Condition cond) {
+  EmitVFPds(cond, B23 | B21 | B20 | B18 | B17 | B16 | B7 | B6, dd, sm);
+}
+
+
+void Assembler::vcvtis(SRegister sd, SRegister sm, Condition cond) {
+  EmitVFPsss(cond, B23 | B21 | B20 | B19 | B18 | B16 | B7 | B6, sd, S0, sm);
+}
+
+
+void Assembler::vcvtid(SRegister sd, DRegister dm, Condition cond) {
+  EmitVFPsd(cond, B23 | B21 | B20 | B19 | B18 | B16 | B8 | B7 | B6, sd, dm);
+}
+
+
+void Assembler::vcvtsi(SRegister sd, SRegister sm, Condition cond) {
+  EmitVFPsss(cond, B23 | B21 | B20 | B19 | B7 | B6, sd, S0, sm);
+}
+
+
+void Assembler::vcvtdi(DRegister dd, SRegister sm, Condition cond) {
+  EmitVFPds(cond, B23 | B21 | B20 | B19 | B8 | B7 | B6, dd, sm);
+}
+
+
+void Assembler::vcvtus(SRegister sd, SRegister sm, Condition cond) {
+  EmitVFPsss(cond, B23 | B21 | B20 | B19 | B18 | B7 | B6, sd, S0, sm);
+}
+
+
+void Assembler::vcvtud(SRegister sd, DRegister dm, Condition cond) {
+  EmitVFPsd(cond, B23 | B21 | B20 | B19 | B18 | B8 | B7 | B6, sd, dm);
+}
+
+
+void Assembler::vcvtsu(SRegister sd, SRegister sm, Condition cond) {
+  EmitVFPsss(cond, B23 | B21 | B20 | B19 | B6, sd, S0, sm);
+}
+
+
+void Assembler::vcvtdu(DRegister dd, SRegister sm, Condition cond) {
+  EmitVFPds(cond, B23 | B21 | B20 | B19 | B8 | B6, dd, sm);
+}
+
+
+void Assembler::vcmps(SRegister sd, SRegister sm, Condition cond) {
+  EmitVFPsss(cond, B23 | B21 | B20 | B18 | B6, sd, S0, sm);
+}
+
+
+void Assembler::vcmpd(DRegister dd, DRegister dm, Condition cond) {
+  EmitVFPddd(cond, B23 | B21 | B20 | B18 | B6, dd, D0, dm);
+}
+
+
+void Assembler::vcmpsz(SRegister sd, Condition cond) {
+  EmitVFPsss(cond, B23 | B21 | B20 | B18 | B16 | B6, sd, S0, S0);
+}
+
+
+void Assembler::vcmpdz(DRegister dd, Condition cond) {
+  EmitVFPddd(cond, B23 | B21 | B20 | B18 | B16 | B6, dd, D0, D0);
+}
+
+
+void Assembler::vmstat(Condition cond) {  // VMRS APSR_nzcv, FPSCR
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B27 | B26 | B25 | B23 | B22 | B21 | B20 | B16 |
+                     (static_cast<int32_t>(PC)*B12) |
+                     B11 | B9 | B4;
+  Emit(encoding);
+}
+
+
+void Assembler::svc(uint32_t imm24) {
+  ASSERT(imm24 < (1 << 24));
+  int32_t encoding = (AL << kConditionShift) | B27 | B26 | B25 | B24 | imm24;
+  Emit(encoding);
+}
+
+
+void Assembler::bkpt(uint16_t imm16) {
+  int32_t encoding = (AL << kConditionShift) | B24 | B21 |
+                     ((imm16 >> 4) << 8) | B6 | B5 | B4 | (imm16 & 0xf);
+  Emit(encoding);
+}
+
+
+void Assembler::b(Label* label, Condition cond) {
+  EmitBranch(cond, label, false);
+}
+
+
+void Assembler::bl(Label* label, Condition cond) {
+  EmitBranch(cond, label, true);
+}
+
+
+void Assembler::blx(Register rm, Condition cond) {
+  ASSERT(rm != kNoRegister);
+  ASSERT(cond != kNoCondition);
+  int32_t encoding = (static_cast<int32_t>(cond) << kConditionShift) |
+                     B24 | B21 | (0xfff << 8) | B5 | B4 |
+                     (static_cast<int32_t>(rm) << kRmShift);
+  Emit(encoding);
+}
+
+
+void Assembler::MarkExceptionHandler(Label* label) {
+  EmitType01(AL, 1, TST, 1, PC, R0, ShifterOperand(0));
+  Label l;
+  b(&l);
+  EmitBranch(AL, label, false);
+  Bind(&l);
+}
+
+
+void Assembler::LoadObject(Register rd, const Object& object) {
+  UNIMPLEMENTED();
+}
+
+
+void Assembler::Bind(Label* label) {
+  ASSERT(!label->IsBound());
+  int bound_pc = buffer_.Size();
+  while (label->IsLinked()) {
+    int32_t position = label->Position();
+    int32_t next = buffer_.Load<int32_t>(position);
+    int32_t encoded = Assembler::EncodeBranchOffset(bound_pc - position, next);
+    buffer_.Store<int32_t>(position, encoded);
+    label->position_ = Assembler::DecodeBranchOffset(next);
+  }
+  label->BindTo(bound_pc);
+}
+
+
+bool Address::CanHoldLoadOffset(LoadOperandType type, int offset) {
+  switch (type) {
+    case kLoadSignedByte:
+    case kLoadSignedHalfword:
+    case kLoadUnsignedHalfword:
+    case kLoadWordPair:
+      return Utils::IsAbsoluteUint(8, offset);  // Addressing mode 3.
+    case kLoadUnsignedByte:
+    case kLoadWord:
+      return Utils::IsAbsoluteUint(12, offset);  // Addressing mode 2.
+    case kLoadSWord:
+    case kLoadDWord:
+      return Utils::IsAbsoluteUint(10, offset);  // VFP addressing mode.
+    default:
+      UNREACHABLE();
+      return false;
+  }
+}
+
+
+bool Address::CanHoldStoreOffset(StoreOperandType type, int offset) {
+  switch (type) {
+    case kStoreHalfword:
+    case kStoreWordPair:
+      return Utils::IsAbsoluteUint(8, offset);  // Addressing mode 3.
+    case kStoreByte:
+    case kStoreWord:
+      return Utils::IsAbsoluteUint(12, offset);  // Addressing mode 2.
+    case kStoreSWord:
+    case kStoreDWord:
+      return Utils::IsAbsoluteUint(10, offset);  // VFP addressing mode.
+    default:
+      UNREACHABLE();
+      return false;
+  }
+}
+
+
+void Assembler::Push(Register rd, Condition cond) {
+  str(rd, Address(SP, -kWordSize, Address::PreIndex), cond);
+}
+
+
+void Assembler::Pop(Register rd, Condition cond) {
+  ldr(rd, Address(SP, kWordSize, Address::PostIndex), cond);
+}
+
+
+void Assembler::PushList(RegList regs, Condition cond) {
+  stm(DB_W, SP, regs, cond);
+}
+
+
+void Assembler::PopList(RegList regs, Condition cond) {
+  ldm(IA_W, SP, regs, cond);
+}
+
+
+void Assembler::Mov(Register rd, Register rm, Condition cond) {
+  if (rd != rm) {
+    mov(rd, ShifterOperand(rm), cond);
+  }
+}
+
+
+void Assembler::Lsl(Register rd, Register rm, uint32_t shift_imm,
+                    Condition cond) {
+  ASSERT(shift_imm != 0);  // Do not use Lsl if no shift is wanted.
+  mov(rd, ShifterOperand(rm, LSL, shift_imm), cond);
+}
+
+
+void Assembler::Lsr(Register rd, Register rm, uint32_t shift_imm,
+                    Condition cond) {
+  ASSERT(shift_imm != 0);  // Do not use Lsr if no shift is wanted.
+  if (shift_imm == 32) shift_imm = 0;  // Comply to UAL syntax.
+  mov(rd, ShifterOperand(rm, LSR, shift_imm), cond);
+}
+
+
+void Assembler::Asr(Register rd, Register rm, uint32_t shift_imm,
+                    Condition cond) {
+  ASSERT(shift_imm != 0);  // Do not use Asr if no shift is wanted.
+  if (shift_imm == 32) shift_imm = 0;  // Comply to UAL syntax.
+  mov(rd, ShifterOperand(rm, ASR, shift_imm), cond);
+}
+
+
+void Assembler::Ror(Register rd, Register rm, uint32_t shift_imm,
+                    Condition cond) {
+  ASSERT(shift_imm != 0);  // Use Rrx instruction.
+  mov(rd, ShifterOperand(rm, ROR, shift_imm), cond);
+}
+
+
+void Assembler::Rrx(Register rd, Register rm, Condition cond) {
+  mov(rd, ShifterOperand(rm, ROR, 0), cond);
+}
+
+
+void Assembler::Branch(const ExternalLabel* label) {
+  // TODO(regis): Revisit this code sequence.
+  LoadImmediate(IP, label->address());  // Target address is never patched.
+  mov(PC, ShifterOperand(IP));
+}
+
+
+void Assembler::BranchLink(const ExternalLabel* label) {
+  // TODO(regis): Revisit this code sequence.
+  // Make sure that CodePatcher is able to patch this code sequence.
+  // For added code robustness, use 'blx lr' in a patchable sequence and
+  // use 'blx ip' in a non-patchable sequence (see other BranchLink flavors).
+  ldr(LR, Address(PC));
+  Label skip;
+  b(&skip);
+  Emit(label->address());  // May get patched.
+  Bind(&skip);
+  blx(LR);  // Use blx instruction so that the return branch prediction works.
+}
+
+
+void Assembler::BranchLinkStore(const ExternalLabel* label, Address ad) {
+  // TODO(regis): Revisit this code sequence.
+  LoadImmediate(IP, label->address());  // Target address is never patched.
+  str(PC, ad);
+  blx(IP);  // Use blx instruction so that the return branch prediction works.
+}
+
+
+void Assembler::BranchLinkOffset(Register base, int offset) {
+  ASSERT(base != PC);
+  ASSERT(base != IP);
+  if (Address::CanHoldLoadOffset(kLoadWord, offset)) {
+    ldr(IP, Address(base, offset));
+  } else {
+    int offset_hi = offset & ~kOffset12Mask;
+    int offset_lo = offset & kOffset12Mask;
+    ShifterOperand offset_hi_op;
+    if (ShifterOperand::CanHold(offset_hi, &offset_hi_op)) {
+      add(IP, base, offset_hi_op);
+      ldr(IP, Address(IP, offset_lo));
+    } else {
+      LoadImmediate(IP, offset_hi);
+      add(IP, IP, ShifterOperand(base));
+      ldr(IP, Address(IP, offset_lo));
+    }
+  }
+  blx(IP);  // Use blx instruction so that the return branch prediction works.
+}
+
+
+void Assembler::LoadImmediate(Register rd, int32_t value, Condition cond) {
+  ShifterOperand shifter_op;
+  if (ShifterOperand::CanHold(value, &shifter_op)) {
+    mov(rd, shifter_op, cond);
+  } else if (ShifterOperand::CanHold(~value, &shifter_op)) {
+    mvn(rd, shifter_op, cond);
+  } else {
+    movw(rd, Utils::Low16Bits(value), cond);
+    uint16_t value_high = Utils::High16Bits(value);
+    if (value_high != 0) {
+      movt(rd, value_high, cond);
+    }
+  }
+}
+
+
+void Assembler::LoadSImmediate(SRegister sd, float value, Condition cond) {
+  if (!vmovs(sd, value, cond)) {
+    LoadImmediate(IP, bit_cast<int32_t, float>(value), cond);
+    vmovsr(sd, IP, cond);
+  }
+}
+
+
+void Assembler::LoadDImmediate(DRegister dd,
+                               double value,
+                               Register scratch,
+                               Condition cond) {
+  // TODO(regis): Revisit this code sequence.
+  ASSERT(scratch != PC);
+  ASSERT(scratch != IP);
+  if (!vmovd(dd, value, cond)) {
+    // A scratch register and IP are needed to load an arbitrary double.
+    ASSERT(scratch != kNoRegister);
+    int64_t imm64 = bit_cast<int64_t, double>(value);
+    LoadImmediate(IP, Utils::Low32Bits(imm64), cond);
+    LoadImmediate(scratch, Utils::High32Bits(imm64), cond);
+    vmovdrr(dd, IP, scratch, cond);
+  }
+}
+
+
+void Assembler::LoadFromOffset(LoadOperandType type,
+                               Register reg,
+                               Register base,
+                               int32_t offset,
+                               Condition cond) {
+  if (!Address::CanHoldLoadOffset(type, offset)) {
+    ASSERT(base != IP);
+    LoadImmediate(IP, offset, cond);
+    add(IP, IP, ShifterOperand(base), cond);
+    base = IP;
+    offset = 0;
+  }
+  ASSERT(Address::CanHoldLoadOffset(type, offset));
+  switch (type) {
+    case kLoadSignedByte:
+      ldrsb(reg, Address(base, offset), cond);
+      break;
+    case kLoadUnsignedByte:
+      ldrb(reg, Address(base, offset), cond);
+      break;
+    case kLoadSignedHalfword:
+      ldrsh(reg, Address(base, offset), cond);
+      break;
+    case kLoadUnsignedHalfword:
+      ldrh(reg, Address(base, offset), cond);
+      break;
+    case kLoadWord:
+      ldr(reg, Address(base, offset), cond);
+      break;
+    case kLoadWordPair:
+      ldrd(reg, Address(base, offset), cond);
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+void Assembler::StoreToOffset(StoreOperandType type,
+                              Register reg,
+                              Register base,
+                              int32_t offset,
+                              Condition cond) {
+  if (!Address::CanHoldStoreOffset(type, offset)) {
+    ASSERT(reg != IP);
+    ASSERT(base != IP);
+    LoadImmediate(IP, offset, cond);
+    add(IP, IP, ShifterOperand(base), cond);
+    base = IP;
+    offset = 0;
+  }
+  ASSERT(Address::CanHoldStoreOffset(type, offset));
+  switch (type) {
+    case kStoreByte:
+      strb(reg, Address(base, offset), cond);
+      break;
+    case kStoreHalfword:
+      strh(reg, Address(base, offset), cond);
+      break;
+    case kStoreWord:
+      str(reg, Address(base, offset), cond);
+      break;
+    case kStoreWordPair:
+      strd(reg, Address(base, offset), cond);
+      break;
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+void Assembler::LoadSFromOffset(SRegister reg,
+                                Register base,
+                                int32_t offset,
+                                Condition cond) {
+  if (!Address::CanHoldLoadOffset(kLoadSWord, offset)) {
+    ASSERT(base != IP);
+    LoadImmediate(IP, offset, cond);
+    add(IP, IP, ShifterOperand(base), cond);
+    base = IP;
+    offset = 0;
+  }
+  ASSERT(Address::CanHoldLoadOffset(kLoadSWord, offset));
+  vldrs(reg, Address(base, offset), cond);
+}
+
+
+void Assembler::StoreSToOffset(SRegister reg,
+                               Register base,
+                               int32_t offset,
+                               Condition cond) {
+  if (!Address::CanHoldStoreOffset(kStoreSWord, offset)) {
+    ASSERT(base != IP);
+    LoadImmediate(IP, offset, cond);
+    add(IP, IP, ShifterOperand(base), cond);
+    base = IP;
+    offset = 0;
+  }
+  ASSERT(Address::CanHoldStoreOffset(kStoreSWord, offset));
+  vstrs(reg, Address(base, offset), cond);
+}
+
+
+void Assembler::LoadDFromOffset(DRegister reg,
+                                Register base,
+                                int32_t offset,
+                                Condition cond) {
+  if (!Address::CanHoldLoadOffset(kLoadDWord, offset)) {
+    ASSERT(base != IP);
+    LoadImmediate(IP, offset, cond);
+    add(IP, IP, ShifterOperand(base), cond);
+    base = IP;
+    offset = 0;
+  }
+  ASSERT(Address::CanHoldLoadOffset(kLoadDWord, offset));
+  vldrd(reg, Address(base, offset), cond);
+}
+
+
+void Assembler::StoreDToOffset(DRegister reg,
+                               Register base,
+                               int32_t offset,
+                               Condition cond) {
+  if (!Address::CanHoldStoreOffset(kStoreDWord, offset)) {
+    ASSERT(base != IP);
+    LoadImmediate(IP, offset, cond);
+    add(IP, IP, ShifterOperand(base), cond);
+    base = IP;
+    offset = 0;
+  }
+  ASSERT(Address::CanHoldStoreOffset(kStoreDWord, offset));
+  vstrd(reg, Address(base, offset), cond);
+}
+
+
+void Assembler::AddConstant(Register rd, int32_t value, Condition cond) {
+  AddConstant(rd, rd, value, cond);
+}
+
+
+void Assembler::AddConstant(Register rd, Register rn, int32_t value,
+                            Condition cond) {
+  if (value == 0) {
+    if (rd != rn) {
+      mov(rd, ShifterOperand(rn), cond);
+    }
+    return;
+  }
+  // We prefer to select the shorter code sequence rather than selecting add for
+  // positive values and sub for negatives ones, which would slightly improve
+  // the readability of generated code for some constants.
+  ShifterOperand shifter_op;
+  if (ShifterOperand::CanHold(value, &shifter_op)) {
+    add(rd, rn, shifter_op, cond);
+  } else if (ShifterOperand::CanHold(-value, &shifter_op)) {
+    sub(rd, rn, shifter_op, cond);
+  } else {
+    ASSERT(rn != IP);
+    if (ShifterOperand::CanHold(~value, &shifter_op)) {
+      mvn(IP, shifter_op, cond);
+      add(rd, rn, ShifterOperand(IP), cond);
+    } else if (ShifterOperand::CanHold(~(-value), &shifter_op)) {
+      mvn(IP, shifter_op, cond);
+      sub(rd, rn, ShifterOperand(IP), cond);
+    } else {
+      movw(IP, Utils::Low16Bits(value), cond);
+      uint16_t value_high = Utils::High16Bits(value);
+      if (value_high != 0) {
+        movt(IP, value_high, cond);
+      }
+      add(rd, rn, ShifterOperand(IP), cond);
+    }
+  }
+}
+
+
+void Assembler::AddConstantSetFlags(Register rd, Register rn, int32_t value,
+                                    Condition cond) {
+  ShifterOperand shifter_op;
+  if (ShifterOperand::CanHold(value, &shifter_op)) {
+    adds(rd, rn, shifter_op, cond);
+  } else if (ShifterOperand::CanHold(-value, &shifter_op)) {
+    subs(rd, rn, shifter_op, cond);
+  } else {
+    ASSERT(rn != IP);
+    if (ShifterOperand::CanHold(~value, &shifter_op)) {
+      mvn(IP, shifter_op, cond);
+      adds(rd, rn, ShifterOperand(IP), cond);
+    } else if (ShifterOperand::CanHold(~(-value), &shifter_op)) {
+      mvn(IP, shifter_op, cond);
+      subs(rd, rn, ShifterOperand(IP), cond);
+    } else {
+      movw(IP, Utils::Low16Bits(value), cond);
+      uint16_t value_high = Utils::High16Bits(value);
+      if (value_high != 0) {
+        movt(IP, value_high, cond);
+      }
+      adds(rd, rn, ShifterOperand(IP), cond);
+    }
+  }
+}
+
+
+void Assembler::AddConstantWithCarry(Register rd, Register rn, int32_t value,
+                                     Condition cond) {
+  ShifterOperand shifter_op;
+  if (ShifterOperand::CanHold(value, &shifter_op)) {
+    adc(rd, rn, shifter_op, cond);
+  } else if (ShifterOperand::CanHold(-value - 1, &shifter_op)) {
+    sbc(rd, rn, shifter_op, cond);
+  } else {
+    ASSERT(rn != IP);
+    if (ShifterOperand::CanHold(~value, &shifter_op)) {
+      mvn(IP, shifter_op, cond);
+      adc(rd, rn, ShifterOperand(IP), cond);
+    } else if (ShifterOperand::CanHold(~(-value - 1), &shifter_op)) {
+      mvn(IP, shifter_op, cond);
+      sbc(rd, rn, ShifterOperand(IP), cond);
+    } else {
+      movw(IP, Utils::Low16Bits(value), cond);
+      uint16_t value_high = Utils::High16Bits(value);
+      if (value_high != 0) {
+        movt(IP, value_high, cond);
+      }
+      adc(rd, rn, ShifterOperand(IP), cond);
+    }
+  }
+}
+
+
+void Assembler::Stop(const char* message) {
+  if (FLAG_print_stop_message) {
+    UNIMPLEMENTED();  // Emit call to StubCode::PrintStopMessage().
+  }
+  // Emit the message address before the svc instruction, so that we can
+  // 'unstop' and continue execution in the simulator or jump to the next
+  // instruction in gdb.
+  Label stop;
+  b(&stop);
+  Emit(reinterpret_cast<int32_t>(message));
+  Bind(&stop);
+  svc(kStopMessageSvcCode);
+}
+
+
+int32_t Assembler::EncodeBranchOffset(int offset, int32_t inst) {
+  // The offset is off by 8 due to the way the ARM CPUs read PC.
+  offset -= 8;
+  ASSERT(Utils::IsAligned(offset, 4));
+  ASSERT(Utils::IsInt(Utils::CountOneBits(kBranchOffsetMask), offset));
+
+  // Properly preserve only the bits supported in the instruction.
+  offset >>= 2;
+  offset &= kBranchOffsetMask;
+  return (inst & ~kBranchOffsetMask) | offset;
+}
+
+
+int Assembler::DecodeBranchOffset(int32_t inst) {
+  // Sign-extend, left-shift by 2, then add 8.
+  return ((((inst & kBranchOffsetMask) << 8) >> 6) + 8);
+}
+
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_ARM