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      1 // Copyright (c) 1994-2006 Sun Microsystems Inc.
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      3 //
      4 // Redistribution and use in source and binary forms, with or without
      5 // modification, are permitted provided that the following conditions
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      7 //
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      9 // this list of conditions and the following disclaimer.
     10 //
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     20 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     21 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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     23 // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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     29 // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     30 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     31 // OF THE POSSIBILITY OF SUCH DAMAGE.
     32 
     33 // The original source code covered by the above license above has been
     34 // modified significantly by Google Inc.
     35 // Copyright 2012 the V8 project authors. All rights reserved.
     36 
     37 #include "src/v8.h"
     38 
     39 #if V8_TARGET_ARCH_ARM
     40 
     41 #include "src/arm/assembler-arm-inl.h"
     42 #include "src/base/bits.h"
     43 #include "src/base/cpu.h"
     44 #include "src/macro-assembler.h"
     45 #include "src/serialize.h"
     46 
     47 namespace v8 {
     48 namespace internal {
     49 
     50 // Get the CPU features enabled by the build. For cross compilation the
     51 // preprocessor symbols CAN_USE_ARMV7_INSTRUCTIONS and CAN_USE_VFP3_INSTRUCTIONS
     52 // can be defined to enable ARMv7 and VFPv3 instructions when building the
     53 // snapshot.
     54 static unsigned CpuFeaturesImpliedByCompiler() {
     55   unsigned answer = 0;
     56 #ifdef CAN_USE_ARMV7_INSTRUCTIONS
     57   if (FLAG_enable_armv7) answer |= 1u << ARMv7;
     58 #endif  // CAN_USE_ARMV7_INSTRUCTIONS
     59 #ifdef CAN_USE_VFP3_INSTRUCTIONS
     60   if (FLAG_enable_vfp3) answer |= 1u << VFP3 | 1u << ARMv7;
     61 #endif  // CAN_USE_VFP3_INSTRUCTIONS
     62 #ifdef CAN_USE_VFP32DREGS
     63   if (FLAG_enable_32dregs) answer |= 1u << VFP32DREGS;
     64 #endif  // CAN_USE_VFP32DREGS
     65 #ifdef CAN_USE_NEON
     66   if (FLAG_enable_neon) answer |= 1u << NEON;
     67 #endif  // CAN_USE_VFP32DREGS
     68   if ((answer & (1u << ARMv7)) && FLAG_enable_unaligned_accesses) {
     69     answer |= 1u << UNALIGNED_ACCESSES;
     70   }
     71 
     72   return answer;
     73 }
     74 
     75 
     76 void CpuFeatures::ProbeImpl(bool cross_compile) {
     77   supported_ |= CpuFeaturesImpliedByCompiler();
     78   cache_line_size_ = 64;
     79 
     80   // Only use statically determined features for cross compile (snapshot).
     81   if (cross_compile) return;
     82 
     83 #ifndef __arm__
     84   // For the simulator build, use whatever the flags specify.
     85   if (FLAG_enable_armv7) {
     86     supported_ |= 1u << ARMv7;
     87     if (FLAG_enable_vfp3) supported_ |= 1u << VFP3;
     88     if (FLAG_enable_neon) supported_ |= 1u << NEON | 1u << VFP32DREGS;
     89     if (FLAG_enable_sudiv) supported_ |= 1u << SUDIV;
     90     if (FLAG_enable_movw_movt) supported_ |= 1u << MOVW_MOVT_IMMEDIATE_LOADS;
     91     if (FLAG_enable_32dregs) supported_ |= 1u << VFP32DREGS;
     92   }
     93   if (FLAG_enable_mls) supported_ |= 1u << MLS;
     94   if (FLAG_enable_unaligned_accesses) supported_ |= 1u << UNALIGNED_ACCESSES;
     95 
     96 #else  // __arm__
     97   // Probe for additional features at runtime.
     98   base::CPU cpu;
     99   if (FLAG_enable_vfp3 && cpu.has_vfp3()) {
    100     // This implementation also sets the VFP flags if runtime
    101     // detection of VFP returns true. VFPv3 implies ARMv7, see ARM DDI
    102     // 0406B, page A1-6.
    103     supported_ |= 1u << VFP3 | 1u << ARMv7;
    104   }
    105 
    106   if (FLAG_enable_neon && cpu.has_neon()) supported_ |= 1u << NEON;
    107   if (FLAG_enable_sudiv && cpu.has_idiva()) supported_ |= 1u << SUDIV;
    108   if (FLAG_enable_mls && cpu.has_thumb2()) supported_ |= 1u << MLS;
    109 
    110   if (cpu.architecture() >= 7) {
    111     if (FLAG_enable_armv7) supported_ |= 1u << ARMv7;
    112     if (FLAG_enable_unaligned_accesses) supported_ |= 1u << UNALIGNED_ACCESSES;
    113     // Use movw/movt for QUALCOMM ARMv7 cores.
    114     if (FLAG_enable_movw_movt && cpu.implementer() == base::CPU::QUALCOMM) {
    115       supported_ |= 1u << MOVW_MOVT_IMMEDIATE_LOADS;
    116     }
    117   }
    118 
    119   // ARM Cortex-A9 and Cortex-A5 have 32 byte cachelines.
    120   if (cpu.implementer() == base::CPU::ARM &&
    121       (cpu.part() == base::CPU::ARM_CORTEX_A5 ||
    122        cpu.part() == base::CPU::ARM_CORTEX_A9)) {
    123     cache_line_size_ = 32;
    124   }
    125 
    126   if (FLAG_enable_32dregs && cpu.has_vfp3_d32()) supported_ |= 1u << VFP32DREGS;
    127 #endif
    128 
    129   DCHECK(!IsSupported(VFP3) || IsSupported(ARMv7));
    130 }
    131 
    132 
    133 void CpuFeatures::PrintTarget() {
    134   const char* arm_arch = NULL;
    135   const char* arm_target_type = "";
    136   const char* arm_no_probe = "";
    137   const char* arm_fpu = "";
    138   const char* arm_thumb = "";
    139   const char* arm_float_abi = NULL;
    140 
    141 #if !defined __arm__
    142   arm_target_type = " simulator";
    143 #endif
    144 
    145 #if defined ARM_TEST_NO_FEATURE_PROBE
    146   arm_no_probe = " noprobe";
    147 #endif
    148 
    149 #if defined CAN_USE_ARMV7_INSTRUCTIONS
    150   arm_arch = "arm v7";
    151 #else
    152   arm_arch = "arm v6";
    153 #endif
    154 
    155 #if defined CAN_USE_NEON
    156   arm_fpu = " neon";
    157 #elif defined CAN_USE_VFP3_INSTRUCTIONS
    158 #  if defined CAN_USE_VFP32DREGS
    159   arm_fpu = " vfp3";
    160 #  else
    161   arm_fpu = " vfp3-d16";
    162 #  endif
    163 #else
    164   arm_fpu = " vfp2";
    165 #endif
    166 
    167 #ifdef __arm__
    168   arm_float_abi = base::OS::ArmUsingHardFloat() ? "hard" : "softfp";
    169 #elif USE_EABI_HARDFLOAT
    170   arm_float_abi = "hard";
    171 #else
    172   arm_float_abi = "softfp";
    173 #endif
    174 
    175 #if defined __arm__ && (defined __thumb__) || (defined __thumb2__)
    176   arm_thumb = " thumb";
    177 #endif
    178 
    179   printf("target%s%s %s%s%s %s\n",
    180          arm_target_type, arm_no_probe, arm_arch, arm_fpu, arm_thumb,
    181          arm_float_abi);
    182 }
    183 
    184 
    185 void CpuFeatures::PrintFeatures() {
    186   printf(
    187     "ARMv7=%d VFP3=%d VFP32DREGS=%d NEON=%d SUDIV=%d UNALIGNED_ACCESSES=%d "
    188     "MOVW_MOVT_IMMEDIATE_LOADS=%d",
    189     CpuFeatures::IsSupported(ARMv7),
    190     CpuFeatures::IsSupported(VFP3),
    191     CpuFeatures::IsSupported(VFP32DREGS),
    192     CpuFeatures::IsSupported(NEON),
    193     CpuFeatures::IsSupported(SUDIV),
    194     CpuFeatures::IsSupported(UNALIGNED_ACCESSES),
    195     CpuFeatures::IsSupported(MOVW_MOVT_IMMEDIATE_LOADS));
    196 #ifdef __arm__
    197   bool eabi_hardfloat = base::OS::ArmUsingHardFloat();
    198 #elif USE_EABI_HARDFLOAT
    199   bool eabi_hardfloat = true;
    200 #else
    201   bool eabi_hardfloat = false;
    202 #endif
    203     printf(" USE_EABI_HARDFLOAT=%d\n", eabi_hardfloat);
    204 }
    205 
    206 
    207 // -----------------------------------------------------------------------------
    208 // Implementation of DwVfpRegister
    209 
    210 const char* DwVfpRegister::AllocationIndexToString(int index) {
    211   DCHECK(index >= 0 && index < NumAllocatableRegisters());
    212   DCHECK(kScratchDoubleReg.code() - kDoubleRegZero.code() ==
    213          kNumReservedRegisters - 1);
    214   if (index >= kDoubleRegZero.code()) index += kNumReservedRegisters;
    215   return VFPRegisters::Name(index, true);
    216 }
    217 
    218 
    219 // -----------------------------------------------------------------------------
    220 // Implementation of RelocInfo
    221 
    222 const int RelocInfo::kApplyMask = 0;
    223 
    224 
    225 bool RelocInfo::IsCodedSpecially() {
    226   // The deserializer needs to know whether a pointer is specially coded. Being
    227   // specially coded on ARM means that it is a movw/movt instruction, or is an
    228   // out of line constant pool entry. These only occur if
    229   // FLAG_enable_ool_constant_pool is true.
    230   return FLAG_enable_ool_constant_pool;
    231 }
    232 
    233 
    234 bool RelocInfo::IsInConstantPool() {
    235   return Assembler::is_constant_pool_load(pc_);
    236 }
    237 
    238 
    239 void RelocInfo::PatchCode(byte* instructions, int instruction_count) {
    240   // Patch the code at the current address with the supplied instructions.
    241   Instr* pc = reinterpret_cast<Instr*>(pc_);
    242   Instr* instr = reinterpret_cast<Instr*>(instructions);
    243   for (int i = 0; i < instruction_count; i++) {
    244     *(pc + i) = *(instr + i);
    245   }
    246 
    247   // Indicate that code has changed.
    248   CpuFeatures::FlushICache(pc_, instruction_count * Assembler::kInstrSize);
    249 }
    250 
    251 
    252 // Patch the code at the current PC with a call to the target address.
    253 // Additional guard instructions can be added if required.
    254 void RelocInfo::PatchCodeWithCall(Address target, int guard_bytes) {
    255   // Patch the code at the current address with a call to the target.
    256   UNIMPLEMENTED();
    257 }
    258 
    259 
    260 // -----------------------------------------------------------------------------
    261 // Implementation of Operand and MemOperand
    262 // See assembler-arm-inl.h for inlined constructors
    263 
    264 Operand::Operand(Handle<Object> handle) {
    265   AllowDeferredHandleDereference using_raw_address;
    266   rm_ = no_reg;
    267   // Verify all Objects referred by code are NOT in new space.
    268   Object* obj = *handle;
    269   if (obj->IsHeapObject()) {
    270     DCHECK(!HeapObject::cast(obj)->GetHeap()->InNewSpace(obj));
    271     imm32_ = reinterpret_cast<intptr_t>(handle.location());
    272     rmode_ = RelocInfo::EMBEDDED_OBJECT;
    273   } else {
    274     // no relocation needed
    275     imm32_ = reinterpret_cast<intptr_t>(obj);
    276     rmode_ = RelocInfo::NONE32;
    277   }
    278 }
    279 
    280 
    281 Operand::Operand(Register rm, ShiftOp shift_op, int shift_imm) {
    282   DCHECK(is_uint5(shift_imm));
    283 
    284   rm_ = rm;
    285   rs_ = no_reg;
    286   shift_op_ = shift_op;
    287   shift_imm_ = shift_imm & 31;
    288 
    289   if ((shift_op == ROR) && (shift_imm == 0)) {
    290     // ROR #0 is functionally equivalent to LSL #0 and this allow us to encode
    291     // RRX as ROR #0 (See below).
    292     shift_op = LSL;
    293   } else if (shift_op == RRX) {
    294     // encoded as ROR with shift_imm == 0
    295     DCHECK(shift_imm == 0);
    296     shift_op_ = ROR;
    297     shift_imm_ = 0;
    298   }
    299 }
    300 
    301 
    302 Operand::Operand(Register rm, ShiftOp shift_op, Register rs) {
    303   DCHECK(shift_op != RRX);
    304   rm_ = rm;
    305   rs_ = no_reg;
    306   shift_op_ = shift_op;
    307   rs_ = rs;
    308 }
    309 
    310 
    311 MemOperand::MemOperand(Register rn, int32_t offset, AddrMode am) {
    312   rn_ = rn;
    313   rm_ = no_reg;
    314   offset_ = offset;
    315   am_ = am;
    316 }
    317 
    318 
    319 MemOperand::MemOperand(Register rn, Register rm, AddrMode am) {
    320   rn_ = rn;
    321   rm_ = rm;
    322   shift_op_ = LSL;
    323   shift_imm_ = 0;
    324   am_ = am;
    325 }
    326 
    327 
    328 MemOperand::MemOperand(Register rn, Register rm,
    329                        ShiftOp shift_op, int shift_imm, AddrMode am) {
    330   DCHECK(is_uint5(shift_imm));
    331   rn_ = rn;
    332   rm_ = rm;
    333   shift_op_ = shift_op;
    334   shift_imm_ = shift_imm & 31;
    335   am_ = am;
    336 }
    337 
    338 
    339 NeonMemOperand::NeonMemOperand(Register rn, AddrMode am, int align) {
    340   DCHECK((am == Offset) || (am == PostIndex));
    341   rn_ = rn;
    342   rm_ = (am == Offset) ? pc : sp;
    343   SetAlignment(align);
    344 }
    345 
    346 
    347 NeonMemOperand::NeonMemOperand(Register rn, Register rm, int align) {
    348   rn_ = rn;
    349   rm_ = rm;
    350   SetAlignment(align);
    351 }
    352 
    353 
    354 void NeonMemOperand::SetAlignment(int align) {
    355   switch (align) {
    356     case 0:
    357       align_ = 0;
    358       break;
    359     case 64:
    360       align_ = 1;
    361       break;
    362     case 128:
    363       align_ = 2;
    364       break;
    365     case 256:
    366       align_ = 3;
    367       break;
    368     default:
    369       UNREACHABLE();
    370       align_ = 0;
    371       break;
    372   }
    373 }
    374 
    375 
    376 NeonListOperand::NeonListOperand(DoubleRegister base, int registers_count) {
    377   base_ = base;
    378   switch (registers_count) {
    379     case 1:
    380       type_ = nlt_1;
    381       break;
    382     case 2:
    383       type_ = nlt_2;
    384       break;
    385     case 3:
    386       type_ = nlt_3;
    387       break;
    388     case 4:
    389       type_ = nlt_4;
    390       break;
    391     default:
    392       UNREACHABLE();
    393       type_ = nlt_1;
    394       break;
    395   }
    396 }
    397 
    398 
    399 // -----------------------------------------------------------------------------
    400 // Specific instructions, constants, and masks.
    401 
    402 // str(r, MemOperand(sp, 4, NegPreIndex), al) instruction (aka push(r))
    403 // register r is not encoded.
    404 const Instr kPushRegPattern =
    405     al | B26 | 4 | NegPreIndex | kRegister_sp_Code * B16;
    406 // ldr(r, MemOperand(sp, 4, PostIndex), al) instruction (aka pop(r))
    407 // register r is not encoded.
    408 const Instr kPopRegPattern =
    409     al | B26 | L | 4 | PostIndex | kRegister_sp_Code * B16;
    410 // ldr rd, [pc, #offset]
    411 const Instr kLdrPCImmedMask = 15 * B24 | 7 * B20 | 15 * B16;
    412 const Instr kLdrPCImmedPattern = 5 * B24 | L | kRegister_pc_Code * B16;
    413 // ldr rd, [pp, #offset]
    414 const Instr kLdrPpImmedMask = 15 * B24 | 7 * B20 | 15 * B16;
    415 const Instr kLdrPpImmedPattern = 5 * B24 | L | kRegister_r8_Code * B16;
    416 // ldr rd, [pp, rn]
    417 const Instr kLdrPpRegMask = 15 * B24 | 7 * B20 | 15 * B16;
    418 const Instr kLdrPpRegPattern = 7 * B24 | L | kRegister_r8_Code * B16;
    419 // vldr dd, [pc, #offset]
    420 const Instr kVldrDPCMask = 15 * B24 | 3 * B20 | 15 * B16 | 15 * B8;
    421 const Instr kVldrDPCPattern = 13 * B24 | L | kRegister_pc_Code * B16 | 11 * B8;
    422 // vldr dd, [pp, #offset]
    423 const Instr kVldrDPpMask = 15 * B24 | 3 * B20 | 15 * B16 | 15 * B8;
    424 const Instr kVldrDPpPattern = 13 * B24 | L | kRegister_r8_Code * B16 | 11 * B8;
    425 // blxcc rm
    426 const Instr kBlxRegMask =
    427     15 * B24 | 15 * B20 | 15 * B16 | 15 * B12 | 15 * B8 | 15 * B4;
    428 const Instr kBlxRegPattern =
    429     B24 | B21 | 15 * B16 | 15 * B12 | 15 * B8 | BLX;
    430 const Instr kBlxIp = al | kBlxRegPattern | ip.code();
    431 const Instr kMovMvnMask = 0x6d * B21 | 0xf * B16;
    432 const Instr kMovMvnPattern = 0xd * B21;
    433 const Instr kMovMvnFlip = B22;
    434 const Instr kMovLeaveCCMask = 0xdff * B16;
    435 const Instr kMovLeaveCCPattern = 0x1a0 * B16;
    436 const Instr kMovwPattern = 0x30 * B20;
    437 const Instr kMovtPattern = 0x34 * B20;
    438 const Instr kMovwLeaveCCFlip = 0x5 * B21;
    439 const Instr kMovImmedMask = 0x7f * B21;
    440 const Instr kMovImmedPattern = 0x1d * B21;
    441 const Instr kOrrImmedMask = 0x7f * B21;
    442 const Instr kOrrImmedPattern = 0x1c * B21;
    443 const Instr kCmpCmnMask = 0xdd * B20 | 0xf * B12;
    444 const Instr kCmpCmnPattern = 0x15 * B20;
    445 const Instr kCmpCmnFlip = B21;
    446 const Instr kAddSubFlip = 0x6 * B21;
    447 const Instr kAndBicFlip = 0xe * B21;
    448 
    449 // A mask for the Rd register for push, pop, ldr, str instructions.
    450 const Instr kLdrRegFpOffsetPattern =
    451     al | B26 | L | Offset | kRegister_fp_Code * B16;
    452 const Instr kStrRegFpOffsetPattern =
    453     al | B26 | Offset | kRegister_fp_Code * B16;
    454 const Instr kLdrRegFpNegOffsetPattern =
    455     al | B26 | L | NegOffset | kRegister_fp_Code * B16;
    456 const Instr kStrRegFpNegOffsetPattern =
    457     al | B26 | NegOffset | kRegister_fp_Code * B16;
    458 const Instr kLdrStrInstrTypeMask = 0xffff0000;
    459 
    460 
    461 Assembler::Assembler(Isolate* isolate, void* buffer, int buffer_size)
    462     : AssemblerBase(isolate, buffer, buffer_size),
    463       recorded_ast_id_(TypeFeedbackId::None()),
    464       constant_pool_builder_(),
    465       positions_recorder_(this) {
    466   reloc_info_writer.Reposition(buffer_ + buffer_size_, pc_);
    467   num_pending_32_bit_reloc_info_ = 0;
    468   num_pending_64_bit_reloc_info_ = 0;
    469   next_buffer_check_ = 0;
    470   const_pool_blocked_nesting_ = 0;
    471   no_const_pool_before_ = 0;
    472   first_const_pool_32_use_ = -1;
    473   first_const_pool_64_use_ = -1;
    474   last_bound_pos_ = 0;
    475   constant_pool_available_ = !FLAG_enable_ool_constant_pool;
    476   ClearRecordedAstId();
    477 }
    478 
    479 
    480 Assembler::~Assembler() {
    481   DCHECK(const_pool_blocked_nesting_ == 0);
    482 }
    483 
    484 
    485 void Assembler::GetCode(CodeDesc* desc) {
    486   if (!FLAG_enable_ool_constant_pool) {
    487     // Emit constant pool if necessary.
    488     CheckConstPool(true, false);
    489     DCHECK(num_pending_32_bit_reloc_info_ == 0);
    490     DCHECK(num_pending_64_bit_reloc_info_ == 0);
    491   }
    492   // Set up code descriptor.
    493   desc->buffer = buffer_;
    494   desc->buffer_size = buffer_size_;
    495   desc->instr_size = pc_offset();
    496   desc->reloc_size = (buffer_ + buffer_size_) - reloc_info_writer.pos();
    497   desc->origin = this;
    498 }
    499 
    500 
    501 void Assembler::Align(int m) {
    502   DCHECK(m >= 4 && base::bits::IsPowerOfTwo32(m));
    503   while ((pc_offset() & (m - 1)) != 0) {
    504     nop();
    505   }
    506 }
    507 
    508 
    509 void Assembler::CodeTargetAlign() {
    510   // Preferred alignment of jump targets on some ARM chips.
    511   Align(8);
    512 }
    513 
    514 
    515 Condition Assembler::GetCondition(Instr instr) {
    516   return Instruction::ConditionField(instr);
    517 }
    518 
    519 
    520 bool Assembler::IsBranch(Instr instr) {
    521   return (instr & (B27 | B25)) == (B27 | B25);
    522 }
    523 
    524 
    525 int Assembler::GetBranchOffset(Instr instr) {
    526   DCHECK(IsBranch(instr));
    527   // Take the jump offset in the lower 24 bits, sign extend it and multiply it
    528   // with 4 to get the offset in bytes.
    529   return ((instr & kImm24Mask) << 8) >> 6;
    530 }
    531 
    532 
    533 bool Assembler::IsLdrRegisterImmediate(Instr instr) {
    534   return (instr & (B27 | B26 | B25 | B22 | B20)) == (B26 | B20);
    535 }
    536 
    537 
    538 bool Assembler::IsVldrDRegisterImmediate(Instr instr) {
    539   return (instr & (15 * B24 | 3 * B20 | 15 * B8)) == (13 * B24 | B20 | 11 * B8);
    540 }
    541 
    542 
    543 int Assembler::GetLdrRegisterImmediateOffset(Instr instr) {
    544   DCHECK(IsLdrRegisterImmediate(instr));
    545   bool positive = (instr & B23) == B23;
    546   int offset = instr & kOff12Mask;  // Zero extended offset.
    547   return positive ? offset : -offset;
    548 }
    549 
    550 
    551 int Assembler::GetVldrDRegisterImmediateOffset(Instr instr) {
    552   DCHECK(IsVldrDRegisterImmediate(instr));
    553   bool positive = (instr & B23) == B23;
    554   int offset = instr & kOff8Mask;  // Zero extended offset.
    555   offset <<= 2;
    556   return positive ? offset : -offset;
    557 }
    558 
    559 
    560 Instr Assembler::SetLdrRegisterImmediateOffset(Instr instr, int offset) {
    561   DCHECK(IsLdrRegisterImmediate(instr));
    562   bool positive = offset >= 0;
    563   if (!positive) offset = -offset;
    564   DCHECK(is_uint12(offset));
    565   // Set bit indicating whether the offset should be added.
    566   instr = (instr & ~B23) | (positive ? B23 : 0);
    567   // Set the actual offset.
    568   return (instr & ~kOff12Mask) | offset;
    569 }
    570 
    571 
    572 Instr Assembler::SetVldrDRegisterImmediateOffset(Instr instr, int offset) {
    573   DCHECK(IsVldrDRegisterImmediate(instr));
    574   DCHECK((offset & ~3) == offset);  // Must be 64-bit aligned.
    575   bool positive = offset >= 0;
    576   if (!positive) offset = -offset;
    577   DCHECK(is_uint10(offset));
    578   // Set bit indicating whether the offset should be added.
    579   instr = (instr & ~B23) | (positive ? B23 : 0);
    580   // Set the actual offset. Its bottom 2 bits are zero.
    581   return (instr & ~kOff8Mask) | (offset >> 2);
    582 }
    583 
    584 
    585 bool Assembler::IsStrRegisterImmediate(Instr instr) {
    586   return (instr & (B27 | B26 | B25 | B22 | B20)) == B26;
    587 }
    588 
    589 
    590 Instr Assembler::SetStrRegisterImmediateOffset(Instr instr, int offset) {
    591   DCHECK(IsStrRegisterImmediate(instr));
    592   bool positive = offset >= 0;
    593   if (!positive) offset = -offset;
    594   DCHECK(is_uint12(offset));
    595   // Set bit indicating whether the offset should be added.
    596   instr = (instr & ~B23) | (positive ? B23 : 0);
    597   // Set the actual offset.
    598   return (instr & ~kOff12Mask) | offset;
    599 }
    600 
    601 
    602 bool Assembler::IsAddRegisterImmediate(Instr instr) {
    603   return (instr & (B27 | B26 | B25 | B24 | B23 | B22 | B21)) == (B25 | B23);
    604 }
    605 
    606 
    607 Instr Assembler::SetAddRegisterImmediateOffset(Instr instr, int offset) {
    608   DCHECK(IsAddRegisterImmediate(instr));
    609   DCHECK(offset >= 0);
    610   DCHECK(is_uint12(offset));
    611   // Set the offset.
    612   return (instr & ~kOff12Mask) | offset;
    613 }
    614 
    615 
    616 Register Assembler::GetRd(Instr instr) {
    617   Register reg;
    618   reg.code_ = Instruction::RdValue(instr);
    619   return reg;
    620 }
    621 
    622 
    623 Register Assembler::GetRn(Instr instr) {
    624   Register reg;
    625   reg.code_ = Instruction::RnValue(instr);
    626   return reg;
    627 }
    628 
    629 
    630 Register Assembler::GetRm(Instr instr) {
    631   Register reg;
    632   reg.code_ = Instruction::RmValue(instr);
    633   return reg;
    634 }
    635 
    636 
    637 Instr Assembler::GetConsantPoolLoadPattern() {
    638   if (FLAG_enable_ool_constant_pool) {
    639     return kLdrPpImmedPattern;
    640   } else {
    641     return kLdrPCImmedPattern;
    642   }
    643 }
    644 
    645 
    646 Instr Assembler::GetConsantPoolLoadMask() {
    647   if (FLAG_enable_ool_constant_pool) {
    648     return kLdrPpImmedMask;
    649   } else {
    650     return kLdrPCImmedMask;
    651   }
    652 }
    653 
    654 
    655 bool Assembler::IsPush(Instr instr) {
    656   return ((instr & ~kRdMask) == kPushRegPattern);
    657 }
    658 
    659 
    660 bool Assembler::IsPop(Instr instr) {
    661   return ((instr & ~kRdMask) == kPopRegPattern);
    662 }
    663 
    664 
    665 bool Assembler::IsStrRegFpOffset(Instr instr) {
    666   return ((instr & kLdrStrInstrTypeMask) == kStrRegFpOffsetPattern);
    667 }
    668 
    669 
    670 bool Assembler::IsLdrRegFpOffset(Instr instr) {
    671   return ((instr & kLdrStrInstrTypeMask) == kLdrRegFpOffsetPattern);
    672 }
    673 
    674 
    675 bool Assembler::IsStrRegFpNegOffset(Instr instr) {
    676   return ((instr & kLdrStrInstrTypeMask) == kStrRegFpNegOffsetPattern);
    677 }
    678 
    679 
    680 bool Assembler::IsLdrRegFpNegOffset(Instr instr) {
    681   return ((instr & kLdrStrInstrTypeMask) == kLdrRegFpNegOffsetPattern);
    682 }
    683 
    684 
    685 bool Assembler::IsLdrPcImmediateOffset(Instr instr) {
    686   // Check the instruction is indeed a
    687   // ldr<cond> <Rd>, [pc +/- offset_12].
    688   return (instr & kLdrPCImmedMask) == kLdrPCImmedPattern;
    689 }
    690 
    691 
    692 bool Assembler::IsLdrPpImmediateOffset(Instr instr) {
    693   // Check the instruction is indeed a
    694   // ldr<cond> <Rd>, [pp +/- offset_12].
    695   return (instr & kLdrPpImmedMask) == kLdrPpImmedPattern;
    696 }
    697 
    698 
    699 bool Assembler::IsLdrPpRegOffset(Instr instr) {
    700   // Check the instruction is indeed a
    701   // ldr<cond> <Rd>, [pp, +/- <Rm>].
    702   return (instr & kLdrPpRegMask) == kLdrPpRegPattern;
    703 }
    704 
    705 
    706 Instr Assembler::GetLdrPpRegOffsetPattern() { return kLdrPpRegPattern; }
    707 
    708 
    709 bool Assembler::IsVldrDPcImmediateOffset(Instr instr) {
    710   // Check the instruction is indeed a
    711   // vldr<cond> <Dd>, [pc +/- offset_10].
    712   return (instr & kVldrDPCMask) == kVldrDPCPattern;
    713 }
    714 
    715 
    716 bool Assembler::IsVldrDPpImmediateOffset(Instr instr) {
    717   // Check the instruction is indeed a
    718   // vldr<cond> <Dd>, [pp +/- offset_10].
    719   return (instr & kVldrDPpMask) == kVldrDPpPattern;
    720 }
    721 
    722 
    723 bool Assembler::IsBlxReg(Instr instr) {
    724   // Check the instruction is indeed a
    725   // blxcc <Rm>
    726   return (instr & kBlxRegMask) == kBlxRegPattern;
    727 }
    728 
    729 
    730 bool Assembler::IsBlxIp(Instr instr) {
    731   // Check the instruction is indeed a
    732   // blx ip
    733   return instr == kBlxIp;
    734 }
    735 
    736 
    737 bool Assembler::IsTstImmediate(Instr instr) {
    738   return (instr & (B27 | B26 | I | kOpCodeMask | S | kRdMask)) ==
    739       (I | TST | S);
    740 }
    741 
    742 
    743 bool Assembler::IsCmpRegister(Instr instr) {
    744   return (instr & (B27 | B26 | I | kOpCodeMask | S | kRdMask | B4)) ==
    745       (CMP | S);
    746 }
    747 
    748 
    749 bool Assembler::IsCmpImmediate(Instr instr) {
    750   return (instr & (B27 | B26 | I | kOpCodeMask | S | kRdMask)) ==
    751       (I | CMP | S);
    752 }
    753 
    754 
    755 Register Assembler::GetCmpImmediateRegister(Instr instr) {
    756   DCHECK(IsCmpImmediate(instr));
    757   return GetRn(instr);
    758 }
    759 
    760 
    761 int Assembler::GetCmpImmediateRawImmediate(Instr instr) {
    762   DCHECK(IsCmpImmediate(instr));
    763   return instr & kOff12Mask;
    764 }
    765 
    766 
    767 // Labels refer to positions in the (to be) generated code.
    768 // There are bound, linked, and unused labels.
    769 //
    770 // Bound labels refer to known positions in the already
    771 // generated code. pos() is the position the label refers to.
    772 //
    773 // Linked labels refer to unknown positions in the code
    774 // to be generated; pos() is the position of the last
    775 // instruction using the label.
    776 //
    777 // The linked labels form a link chain by making the branch offset
    778 // in the instruction steam to point to the previous branch
    779 // instruction using the same label.
    780 //
    781 // The link chain is terminated by a branch offset pointing to the
    782 // same position.
    783 
    784 
    785 int Assembler::target_at(int pos) {
    786   Instr instr = instr_at(pos);
    787   if (is_uint24(instr)) {
    788     // Emitted link to a label, not part of a branch.
    789     return instr;
    790   }
    791   DCHECK((instr & 7*B25) == 5*B25);  // b, bl, or blx imm24
    792   int imm26 = ((instr & kImm24Mask) << 8) >> 6;
    793   if ((Instruction::ConditionField(instr) == kSpecialCondition) &&
    794       ((instr & B24) != 0)) {
    795     // blx uses bit 24 to encode bit 2 of imm26
    796     imm26 += 2;
    797   }
    798   return pos + kPcLoadDelta + imm26;
    799 }
    800 
    801 
    802 void Assembler::target_at_put(int pos, int target_pos) {
    803   Instr instr = instr_at(pos);
    804   if (is_uint24(instr)) {
    805     DCHECK(target_pos == pos || target_pos >= 0);
    806     // Emitted link to a label, not part of a branch.
    807     // Load the position of the label relative to the generated code object
    808     // pointer in a register.
    809 
    810     // Here are the instructions we need to emit:
    811     //   For ARMv7: target24 => target16_1:target16_0
    812     //      movw dst, #target16_0
    813     //      movt dst, #target16_1
    814     //   For ARMv6: target24 => target8_2:target8_1:target8_0
    815     //      mov dst, #target8_0
    816     //      orr dst, dst, #target8_1 << 8
    817     //      orr dst, dst, #target8_2 << 16
    818 
    819     // We extract the destination register from the emitted nop instruction.
    820     Register dst = Register::from_code(
    821         Instruction::RmValue(instr_at(pos + kInstrSize)));
    822     DCHECK(IsNop(instr_at(pos + kInstrSize), dst.code()));
    823     uint32_t target24 = target_pos + (Code::kHeaderSize - kHeapObjectTag);
    824     DCHECK(is_uint24(target24));
    825     if (is_uint8(target24)) {
    826       // If the target fits in a byte then only patch with a mov
    827       // instruction.
    828       CodePatcher patcher(reinterpret_cast<byte*>(buffer_ + pos),
    829                           1,
    830                           CodePatcher::DONT_FLUSH);
    831       patcher.masm()->mov(dst, Operand(target24));
    832     } else {
    833       uint16_t target16_0 = target24 & kImm16Mask;
    834       uint16_t target16_1 = target24 >> 16;
    835       if (CpuFeatures::IsSupported(ARMv7)) {
    836         // Patch with movw/movt.
    837         if (target16_1 == 0) {
    838           CodePatcher patcher(reinterpret_cast<byte*>(buffer_ + pos),
    839                               1,
    840                               CodePatcher::DONT_FLUSH);
    841           patcher.masm()->movw(dst, target16_0);
    842         } else {
    843           CodePatcher patcher(reinterpret_cast<byte*>(buffer_ + pos),
    844                               2,
    845                               CodePatcher::DONT_FLUSH);
    846           patcher.masm()->movw(dst, target16_0);
    847           patcher.masm()->movt(dst, target16_1);
    848         }
    849       } else {
    850         // Patch with a sequence of mov/orr/orr instructions.
    851         uint8_t target8_0 = target16_0 & kImm8Mask;
    852         uint8_t target8_1 = target16_0 >> 8;
    853         uint8_t target8_2 = target16_1 & kImm8Mask;
    854         if (target8_2 == 0) {
    855           CodePatcher patcher(reinterpret_cast<byte*>(buffer_ + pos),
    856                               2,
    857                               CodePatcher::DONT_FLUSH);
    858           patcher.masm()->mov(dst, Operand(target8_0));
    859           patcher.masm()->orr(dst, dst, Operand(target8_1 << 8));
    860         } else {
    861           CodePatcher patcher(reinterpret_cast<byte*>(buffer_ + pos),
    862                               3,
    863                               CodePatcher::DONT_FLUSH);
    864           patcher.masm()->mov(dst, Operand(target8_0));
    865           patcher.masm()->orr(dst, dst, Operand(target8_1 << 8));
    866           patcher.masm()->orr(dst, dst, Operand(target8_2 << 16));
    867         }
    868       }
    869     }
    870     return;
    871   }
    872   int imm26 = target_pos - (pos + kPcLoadDelta);
    873   DCHECK((instr & 7*B25) == 5*B25);  // b, bl, or blx imm24
    874   if (Instruction::ConditionField(instr) == kSpecialCondition) {
    875     // blx uses bit 24 to encode bit 2 of imm26
    876     DCHECK((imm26 & 1) == 0);
    877     instr = (instr & ~(B24 | kImm24Mask)) | ((imm26 & 2) >> 1)*B24;
    878   } else {
    879     DCHECK((imm26 & 3) == 0);
    880     instr &= ~kImm24Mask;
    881   }
    882   int imm24 = imm26 >> 2;
    883   DCHECK(is_int24(imm24));
    884   instr_at_put(pos, instr | (imm24 & kImm24Mask));
    885 }
    886 
    887 
    888 void Assembler::print(Label* L) {
    889   if (L->is_unused()) {
    890     PrintF("unused label\n");
    891   } else if (L->is_bound()) {
    892     PrintF("bound label to %d\n", L->pos());
    893   } else if (L->is_linked()) {
    894     Label l = *L;
    895     PrintF("unbound label");
    896     while (l.is_linked()) {
    897       PrintF("@ %d ", l.pos());
    898       Instr instr = instr_at(l.pos());
    899       if ((instr & ~kImm24Mask) == 0) {
    900         PrintF("value\n");
    901       } else {
    902         DCHECK((instr & 7*B25) == 5*B25);  // b, bl, or blx
    903         Condition cond = Instruction::ConditionField(instr);
    904         const char* b;
    905         const char* c;
    906         if (cond == kSpecialCondition) {
    907           b = "blx";
    908           c = "";
    909         } else {
    910           if ((instr & B24) != 0)
    911             b = "bl";
    912           else
    913             b = "b";
    914 
    915           switch (cond) {
    916             case eq: c = "eq"; break;
    917             case ne: c = "ne"; break;
    918             case hs: c = "hs"; break;
    919             case lo: c = "lo"; break;
    920             case mi: c = "mi"; break;
    921             case pl: c = "pl"; break;
    922             case vs: c = "vs"; break;
    923             case vc: c = "vc"; break;
    924             case hi: c = "hi"; break;
    925             case ls: c = "ls"; break;
    926             case ge: c = "ge"; break;
    927             case lt: c = "lt"; break;
    928             case gt: c = "gt"; break;
    929             case le: c = "le"; break;
    930             case al: c = ""; break;
    931             default:
    932               c = "";
    933               UNREACHABLE();
    934           }
    935         }
    936         PrintF("%s%s\n", b, c);
    937       }
    938       next(&l);
    939     }
    940   } else {
    941     PrintF("label in inconsistent state (pos = %d)\n", L->pos_);
    942   }
    943 }
    944 
    945 
    946 void Assembler::bind_to(Label* L, int pos) {
    947   DCHECK(0 <= pos && pos <= pc_offset());  // must have a valid binding position
    948   while (L->is_linked()) {
    949     int fixup_pos = L->pos();
    950     next(L);  // call next before overwriting link with target at fixup_pos
    951     target_at_put(fixup_pos, pos);
    952   }
    953   L->bind_to(pos);
    954 
    955   // Keep track of the last bound label so we don't eliminate any instructions
    956   // before a bound label.
    957   if (pos > last_bound_pos_)
    958     last_bound_pos_ = pos;
    959 }
    960 
    961 
    962 void Assembler::bind(Label* L) {
    963   DCHECK(!L->is_bound());  // label can only be bound once
    964   bind_to(L, pc_offset());
    965 }
    966 
    967 
    968 void Assembler::next(Label* L) {
    969   DCHECK(L->is_linked());
    970   int link = target_at(L->pos());
    971   if (link == L->pos()) {
    972     // Branch target points to the same instuction. This is the end of the link
    973     // chain.
    974     L->Unuse();
    975   } else {
    976     DCHECK(link >= 0);
    977     L->link_to(link);
    978   }
    979 }
    980 
    981 
    982 // Low-level code emission routines depending on the addressing mode.
    983 // If this returns true then you have to use the rotate_imm and immed_8
    984 // that it returns, because it may have already changed the instruction
    985 // to match them!
    986 static bool fits_shifter(uint32_t imm32,
    987                          uint32_t* rotate_imm,
    988                          uint32_t* immed_8,
    989                          Instr* instr) {
    990   // imm32 must be unsigned.
    991   for (int rot = 0; rot < 16; rot++) {
    992     uint32_t imm8 = (imm32 << 2*rot) | (imm32 >> (32 - 2*rot));
    993     if ((imm8 <= 0xff)) {
    994       *rotate_imm = rot;
    995       *immed_8 = imm8;
    996       return true;
    997     }
    998   }
    999   // If the opcode is one with a complementary version and the complementary
   1000   // immediate fits, change the opcode.
   1001   if (instr != NULL) {
   1002     if ((*instr & kMovMvnMask) == kMovMvnPattern) {
   1003       if (fits_shifter(~imm32, rotate_imm, immed_8, NULL)) {
   1004         *instr ^= kMovMvnFlip;
   1005         return true;
   1006       } else if ((*instr & kMovLeaveCCMask) == kMovLeaveCCPattern) {
   1007         if (CpuFeatures::IsSupported(ARMv7)) {
   1008           if (imm32 < 0x10000) {
   1009             *instr ^= kMovwLeaveCCFlip;
   1010             *instr |= Assembler::EncodeMovwImmediate(imm32);
   1011             *rotate_imm = *immed_8 = 0;  // Not used for movw.
   1012             return true;
   1013           }
   1014         }
   1015       }
   1016     } else if ((*instr & kCmpCmnMask) == kCmpCmnPattern) {
   1017       if (fits_shifter(-static_cast<int>(imm32), rotate_imm, immed_8, NULL)) {
   1018         *instr ^= kCmpCmnFlip;
   1019         return true;
   1020       }
   1021     } else {
   1022       Instr alu_insn = (*instr & kALUMask);
   1023       if (alu_insn == ADD ||
   1024           alu_insn == SUB) {
   1025         if (fits_shifter(-static_cast<int>(imm32), rotate_imm, immed_8, NULL)) {
   1026           *instr ^= kAddSubFlip;
   1027           return true;
   1028         }
   1029       } else if (alu_insn == AND ||
   1030                  alu_insn == BIC) {
   1031         if (fits_shifter(~imm32, rotate_imm, immed_8, NULL)) {
   1032           *instr ^= kAndBicFlip;
   1033           return true;
   1034         }
   1035       }
   1036     }
   1037   }
   1038   return false;
   1039 }
   1040 
   1041 
   1042 // We have to use the temporary register for things that can be relocated even
   1043 // if they can be encoded in the ARM's 12 bits of immediate-offset instruction
   1044 // space.  There is no guarantee that the relocated location can be similarly
   1045 // encoded.
   1046 bool Operand::must_output_reloc_info(const Assembler* assembler) const {
   1047   if (rmode_ == RelocInfo::EXTERNAL_REFERENCE) {
   1048     if (assembler != NULL && assembler->predictable_code_size()) return true;
   1049     return assembler->serializer_enabled();
   1050   } else if (RelocInfo::IsNone(rmode_)) {
   1051     return false;
   1052   }
   1053   return true;
   1054 }
   1055 
   1056 
   1057 static bool use_mov_immediate_load(const Operand& x,
   1058                                    const Assembler* assembler) {
   1059   if (assembler != NULL && !assembler->is_constant_pool_available()) {
   1060     return true;
   1061   } else if (CpuFeatures::IsSupported(MOVW_MOVT_IMMEDIATE_LOADS) &&
   1062              (assembler == NULL || !assembler->predictable_code_size())) {
   1063     // Prefer movw / movt to constant pool if it is more efficient on the CPU.
   1064     return true;
   1065   } else if (x.must_output_reloc_info(assembler)) {
   1066     // Prefer constant pool if data is likely to be patched.
   1067     return false;
   1068   } else {
   1069     // Otherwise, use immediate load if movw / movt is available.
   1070     return CpuFeatures::IsSupported(ARMv7);
   1071   }
   1072 }
   1073 
   1074 
   1075 int Operand::instructions_required(const Assembler* assembler,
   1076                                    Instr instr) const {
   1077   if (rm_.is_valid()) return 1;
   1078   uint32_t dummy1, dummy2;
   1079   if (must_output_reloc_info(assembler) ||
   1080       !fits_shifter(imm32_, &dummy1, &dummy2, &instr)) {
   1081     // The immediate operand cannot be encoded as a shifter operand, or use of
   1082     // constant pool is required.  First account for the instructions required
   1083     // for the constant pool or immediate load
   1084     int instructions;
   1085     if (use_mov_immediate_load(*this, assembler)) {
   1086       // A movw / movt or mov / orr immediate load.
   1087       instructions = CpuFeatures::IsSupported(ARMv7) ? 2 : 4;
   1088     } else if (assembler != NULL && assembler->use_extended_constant_pool()) {
   1089       // An extended constant pool load.
   1090       instructions = CpuFeatures::IsSupported(ARMv7) ? 3 : 5;
   1091     } else {
   1092       // A small constant pool load.
   1093       instructions = 1;
   1094     }
   1095 
   1096     if ((instr & ~kCondMask) != 13 * B21) {  // mov, S not set
   1097       // For a mov or mvn instruction which doesn't set the condition
   1098       // code, the constant pool or immediate load is enough, otherwise we need
   1099       // to account for the actual instruction being requested.
   1100       instructions += 1;
   1101     }
   1102     return instructions;
   1103   } else {
   1104     // No use of constant pool and the immediate operand can be encoded as a
   1105     // shifter operand.
   1106     return 1;
   1107   }
   1108 }
   1109 
   1110 
   1111 void Assembler::move_32_bit_immediate(Register rd,
   1112                                       const Operand& x,
   1113                                       Condition cond) {
   1114   RelocInfo rinfo(pc_, x.rmode_, x.imm32_, NULL);
   1115   uint32_t imm32 = static_cast<uint32_t>(x.imm32_);
   1116   if (x.must_output_reloc_info(this)) {
   1117     RecordRelocInfo(rinfo);
   1118   }
   1119 
   1120   if (use_mov_immediate_load(x, this)) {
   1121     Register target = rd.code() == pc.code() ? ip : rd;
   1122     if (CpuFeatures::IsSupported(ARMv7)) {
   1123       if (!FLAG_enable_ool_constant_pool && x.must_output_reloc_info(this)) {
   1124         // Make sure the movw/movt doesn't get separated.
   1125         BlockConstPoolFor(2);
   1126       }
   1127       movw(target, imm32 & 0xffff, cond);
   1128       movt(target, imm32 >> 16, cond);
   1129     } else {
   1130       DCHECK(FLAG_enable_ool_constant_pool);
   1131       mov(target, Operand(imm32 & kImm8Mask), LeaveCC, cond);
   1132       orr(target, target, Operand(imm32 & (kImm8Mask << 8)), LeaveCC, cond);
   1133       orr(target, target, Operand(imm32 & (kImm8Mask << 16)), LeaveCC, cond);
   1134       orr(target, target, Operand(imm32 & (kImm8Mask << 24)), LeaveCC, cond);
   1135     }
   1136     if (target.code() != rd.code()) {
   1137       mov(rd, target, LeaveCC, cond);
   1138     }
   1139   } else {
   1140     DCHECK(is_constant_pool_available());
   1141     ConstantPoolArray::LayoutSection section = ConstantPoolAddEntry(rinfo);
   1142     if (section == ConstantPoolArray::EXTENDED_SECTION) {
   1143       DCHECK(FLAG_enable_ool_constant_pool);
   1144       Register target = rd.code() == pc.code() ? ip : rd;
   1145       // Emit instructions to load constant pool offset.
   1146       if (CpuFeatures::IsSupported(ARMv7)) {
   1147         movw(target, 0, cond);
   1148         movt(target, 0, cond);
   1149       } else {
   1150         mov(target, Operand(0), LeaveCC, cond);
   1151         orr(target, target, Operand(0), LeaveCC, cond);
   1152         orr(target, target, Operand(0), LeaveCC, cond);
   1153         orr(target, target, Operand(0), LeaveCC, cond);
   1154       }
   1155       // Load from constant pool at offset.
   1156       ldr(rd, MemOperand(pp, target), cond);
   1157     } else {
   1158       DCHECK(section == ConstantPoolArray::SMALL_SECTION);
   1159       ldr(rd, MemOperand(FLAG_enable_ool_constant_pool ? pp : pc, 0), cond);
   1160     }
   1161   }
   1162 }
   1163 
   1164 
   1165 void Assembler::addrmod1(Instr instr,
   1166                          Register rn,
   1167                          Register rd,
   1168                          const Operand& x) {
   1169   CheckBuffer();
   1170   DCHECK((instr & ~(kCondMask | kOpCodeMask | S)) == 0);
   1171   if (!x.rm_.is_valid()) {
   1172     // Immediate.
   1173     uint32_t rotate_imm;
   1174     uint32_t immed_8;
   1175     if (x.must_output_reloc_info(this) ||
   1176         !fits_shifter(x.imm32_, &rotate_imm, &immed_8, &instr)) {
   1177       // The immediate operand cannot be encoded as a shifter operand, so load
   1178       // it first to register ip and change the original instruction to use ip.
   1179       // However, if the original instruction is a 'mov rd, x' (not setting the
   1180       // condition code), then replace it with a 'ldr rd, [pc]'.
   1181       CHECK(!rn.is(ip));  // rn should never be ip, or will be trashed
   1182       Condition cond = Instruction::ConditionField(instr);
   1183       if ((instr & ~kCondMask) == 13*B21) {  // mov, S not set
   1184         move_32_bit_immediate(rd, x, cond);
   1185       } else {
   1186         mov(ip, x, LeaveCC, cond);
   1187         addrmod1(instr, rn, rd, Operand(ip));
   1188       }
   1189       return;
   1190     }
   1191     instr |= I | rotate_imm*B8 | immed_8;
   1192   } else if (!x.rs_.is_valid()) {
   1193     // Immediate shift.
   1194     instr |= x.shift_imm_*B7 | x.shift_op_ | x.rm_.code();
   1195   } else {
   1196     // Register shift.
   1197     DCHECK(!rn.is(pc) && !rd.is(pc) && !x.rm_.is(pc) && !x.rs_.is(pc));
   1198     instr |= x.rs_.code()*B8 | x.shift_op_ | B4 | x.rm_.code();
   1199   }
   1200   emit(instr | rn.code()*B16 | rd.code()*B12);
   1201   if (rn.is(pc) || x.rm_.is(pc)) {
   1202     // Block constant pool emission for one instruction after reading pc.
   1203     BlockConstPoolFor(1);
   1204   }
   1205 }
   1206 
   1207 
   1208 void Assembler::addrmod2(Instr instr, Register rd, const MemOperand& x) {
   1209   DCHECK((instr & ~(kCondMask | B | L)) == B26);
   1210   int am = x.am_;
   1211   if (!x.rm_.is_valid()) {
   1212     // Immediate offset.
   1213     int offset_12 = x.offset_;
   1214     if (offset_12 < 0) {
   1215       offset_12 = -offset_12;
   1216       am ^= U;
   1217     }
   1218     if (!is_uint12(offset_12)) {
   1219       // Immediate offset cannot be encoded, load it first to register ip
   1220       // rn (and rd in a load) should never be ip, or will be trashed.
   1221       DCHECK(!x.rn_.is(ip) && ((instr & L) == L || !rd.is(ip)));
   1222       mov(ip, Operand(x.offset_), LeaveCC, Instruction::ConditionField(instr));
   1223       addrmod2(instr, rd, MemOperand(x.rn_, ip, x.am_));
   1224       return;
   1225     }
   1226     DCHECK(offset_12 >= 0);  // no masking needed
   1227     instr |= offset_12;
   1228   } else {
   1229     // Register offset (shift_imm_ and shift_op_ are 0) or scaled
   1230     // register offset the constructors make sure than both shift_imm_
   1231     // and shift_op_ are initialized.
   1232     DCHECK(!x.rm_.is(pc));
   1233     instr |= B25 | x.shift_imm_*B7 | x.shift_op_ | x.rm_.code();
   1234   }
   1235   DCHECK((am & (P|W)) == P || !x.rn_.is(pc));  // no pc base with writeback
   1236   emit(instr | am | x.rn_.code()*B16 | rd.code()*B12);
   1237 }
   1238 
   1239 
   1240 void Assembler::addrmod3(Instr instr, Register rd, const MemOperand& x) {
   1241   DCHECK((instr & ~(kCondMask | L | S6 | H)) == (B4 | B7));
   1242   DCHECK(x.rn_.is_valid());
   1243   int am = x.am_;
   1244   if (!x.rm_.is_valid()) {
   1245     // Immediate offset.
   1246     int offset_8 = x.offset_;
   1247     if (offset_8 < 0) {
   1248       offset_8 = -offset_8;
   1249       am ^= U;
   1250     }
   1251     if (!is_uint8(offset_8)) {
   1252       // Immediate offset cannot be encoded, load it first to register ip
   1253       // rn (and rd in a load) should never be ip, or will be trashed.
   1254       DCHECK(!x.rn_.is(ip) && ((instr & L) == L || !rd.is(ip)));
   1255       mov(ip, Operand(x.offset_), LeaveCC, Instruction::ConditionField(instr));
   1256       addrmod3(instr, rd, MemOperand(x.rn_, ip, x.am_));
   1257       return;
   1258     }
   1259     DCHECK(offset_8 >= 0);  // no masking needed
   1260     instr |= B | (offset_8 >> 4)*B8 | (offset_8 & 0xf);
   1261   } else if (x.shift_imm_ != 0) {
   1262     // Scaled register offset not supported, load index first
   1263     // rn (and rd in a load) should never be ip, or will be trashed.
   1264     DCHECK(!x.rn_.is(ip) && ((instr & L) == L || !rd.is(ip)));
   1265     mov(ip, Operand(x.rm_, x.shift_op_, x.shift_imm_), LeaveCC,
   1266         Instruction::ConditionField(instr));
   1267     addrmod3(instr, rd, MemOperand(x.rn_, ip, x.am_));
   1268     return;
   1269   } else {
   1270     // Register offset.
   1271     DCHECK((am & (P|W)) == P || !x.rm_.is(pc));  // no pc index with writeback
   1272     instr |= x.rm_.code();
   1273   }
   1274   DCHECK((am & (P|W)) == P || !x.rn_.is(pc));  // no pc base with writeback
   1275   emit(instr | am | x.rn_.code()*B16 | rd.code()*B12);
   1276 }
   1277 
   1278 
   1279 void Assembler::addrmod4(Instr instr, Register rn, RegList rl) {
   1280   DCHECK((instr & ~(kCondMask | P | U | W | L)) == B27);
   1281   DCHECK(rl != 0);
   1282   DCHECK(!rn.is(pc));
   1283   emit(instr | rn.code()*B16 | rl);
   1284 }
   1285 
   1286 
   1287 void Assembler::addrmod5(Instr instr, CRegister crd, const MemOperand& x) {
   1288   // Unindexed addressing is not encoded by this function.
   1289   DCHECK_EQ((B27 | B26),
   1290             (instr & ~(kCondMask | kCoprocessorMask | P | U | N | W | L)));
   1291   DCHECK(x.rn_.is_valid() && !x.rm_.is_valid());
   1292   int am = x.am_;
   1293   int offset_8 = x.offset_;
   1294   DCHECK((offset_8 & 3) == 0);  // offset must be an aligned word offset
   1295   offset_8 >>= 2;
   1296   if (offset_8 < 0) {
   1297     offset_8 = -offset_8;
   1298     am ^= U;
   1299   }
   1300   DCHECK(is_uint8(offset_8));  // unsigned word offset must fit in a byte
   1301   DCHECK((am & (P|W)) == P || !x.rn_.is(pc));  // no pc base with writeback
   1302 
   1303   // Post-indexed addressing requires W == 1; different than in addrmod2/3.
   1304   if ((am & P) == 0)
   1305     am |= W;
   1306 
   1307   DCHECK(offset_8 >= 0);  // no masking needed
   1308   emit(instr | am | x.rn_.code()*B16 | crd.code()*B12 | offset_8);
   1309 }
   1310 
   1311 
   1312 int Assembler::branch_offset(Label* L, bool jump_elimination_allowed) {
   1313   int target_pos;
   1314   if (L->is_bound()) {
   1315     target_pos = L->pos();
   1316   } else {
   1317     if (L->is_linked()) {
   1318       // Point to previous instruction that uses the link.
   1319       target_pos = L->pos();
   1320     } else {
   1321       // First entry of the link chain points to itself.
   1322       target_pos = pc_offset();
   1323     }
   1324     L->link_to(pc_offset());
   1325   }
   1326 
   1327   // Block the emission of the constant pool, since the branch instruction must
   1328   // be emitted at the pc offset recorded by the label.
   1329   BlockConstPoolFor(1);
   1330   return target_pos - (pc_offset() + kPcLoadDelta);
   1331 }
   1332 
   1333 
   1334 // Branch instructions.
   1335 void Assembler::b(int branch_offset, Condition cond) {
   1336   DCHECK((branch_offset & 3) == 0);
   1337   int imm24 = branch_offset >> 2;
   1338   DCHECK(is_int24(imm24));
   1339   emit(cond | B27 | B25 | (imm24 & kImm24Mask));
   1340 
   1341   if (cond == al) {
   1342     // Dead code is a good location to emit the constant pool.
   1343     CheckConstPool(false, false);
   1344   }
   1345 }
   1346 
   1347 
   1348 void Assembler::bl(int branch_offset, Condition cond) {
   1349   positions_recorder()->WriteRecordedPositions();
   1350   DCHECK((branch_offset & 3) == 0);
   1351   int imm24 = branch_offset >> 2;
   1352   DCHECK(is_int24(imm24));
   1353   emit(cond | B27 | B25 | B24 | (imm24 & kImm24Mask));
   1354 }
   1355 
   1356 
   1357 void Assembler::blx(int branch_offset) {  // v5 and above
   1358   positions_recorder()->WriteRecordedPositions();
   1359   DCHECK((branch_offset & 1) == 0);
   1360   int h = ((branch_offset & 2) >> 1)*B24;
   1361   int imm24 = branch_offset >> 2;
   1362   DCHECK(is_int24(imm24));
   1363   emit(kSpecialCondition | B27 | B25 | h | (imm24 & kImm24Mask));
   1364 }
   1365 
   1366 
   1367 void Assembler::blx(Register target, Condition cond) {  // v5 and above
   1368   positions_recorder()->WriteRecordedPositions();
   1369   DCHECK(!target.is(pc));
   1370   emit(cond | B24 | B21 | 15*B16 | 15*B12 | 15*B8 | BLX | target.code());
   1371 }
   1372 
   1373 
   1374 void Assembler::bx(Register target, Condition cond) {  // v5 and above, plus v4t
   1375   positions_recorder()->WriteRecordedPositions();
   1376   DCHECK(!target.is(pc));  // use of pc is actually allowed, but discouraged
   1377   emit(cond | B24 | B21 | 15*B16 | 15*B12 | 15*B8 | BX | target.code());
   1378 }
   1379 
   1380 
   1381 // Data-processing instructions.
   1382 
   1383 void Assembler::and_(Register dst, Register src1, const Operand& src2,
   1384                      SBit s, Condition cond) {
   1385   addrmod1(cond | AND | s, src1, dst, src2);
   1386 }
   1387 
   1388 
   1389 void Assembler::eor(Register dst, Register src1, const Operand& src2,
   1390                     SBit s, Condition cond) {
   1391   addrmod1(cond | EOR | s, src1, dst, src2);
   1392 }
   1393 
   1394 
   1395 void Assembler::sub(Register dst, Register src1, const Operand& src2,
   1396                     SBit s, Condition cond) {
   1397   addrmod1(cond | SUB | s, src1, dst, src2);
   1398 }
   1399 
   1400 
   1401 void Assembler::rsb(Register dst, Register src1, const Operand& src2,
   1402                     SBit s, Condition cond) {
   1403   addrmod1(cond | RSB | s, src1, dst, src2);
   1404 }
   1405 
   1406 
   1407 void Assembler::add(Register dst, Register src1, const Operand& src2,
   1408                     SBit s, Condition cond) {
   1409   addrmod1(cond | ADD | s, src1, dst, src2);
   1410 }
   1411 
   1412 
   1413 void Assembler::adc(Register dst, Register src1, const Operand& src2,
   1414                     SBit s, Condition cond) {
   1415   addrmod1(cond | ADC | s, src1, dst, src2);
   1416 }
   1417 
   1418 
   1419 void Assembler::sbc(Register dst, Register src1, const Operand& src2,
   1420                     SBit s, Condition cond) {
   1421   addrmod1(cond | SBC | s, src1, dst, src2);
   1422 }
   1423 
   1424 
   1425 void Assembler::rsc(Register dst, Register src1, const Operand& src2,
   1426                     SBit s, Condition cond) {
   1427   addrmod1(cond | RSC | s, src1, dst, src2);
   1428 }
   1429 
   1430 
   1431 void Assembler::tst(Register src1, const Operand& src2, Condition cond) {
   1432   addrmod1(cond | TST | S, src1, r0, src2);
   1433 }
   1434 
   1435 
   1436 void Assembler::teq(Register src1, const Operand& src2, Condition cond) {
   1437   addrmod1(cond | TEQ | S, src1, r0, src2);
   1438 }
   1439 
   1440 
   1441 void Assembler::cmp(Register src1, const Operand& src2, Condition cond) {
   1442   addrmod1(cond | CMP | S, src1, r0, src2);
   1443 }
   1444 
   1445 
   1446 void Assembler::cmp_raw_immediate(
   1447     Register src, int raw_immediate, Condition cond) {
   1448   DCHECK(is_uint12(raw_immediate));
   1449   emit(cond | I | CMP | S | src.code() << 16 | raw_immediate);
   1450 }
   1451 
   1452 
   1453 void Assembler::cmn(Register src1, const Operand& src2, Condition cond) {
   1454   addrmod1(cond | CMN | S, src1, r0, src2);
   1455 }
   1456 
   1457 
   1458 void Assembler::orr(Register dst, Register src1, const Operand& src2,
   1459                     SBit s, Condition cond) {
   1460   addrmod1(cond | ORR | s, src1, dst, src2);
   1461 }
   1462 
   1463 
   1464 void Assembler::mov(Register dst, const Operand& src, SBit s, Condition cond) {
   1465   if (dst.is(pc)) {
   1466     positions_recorder()->WriteRecordedPositions();
   1467   }
   1468   // Don't allow nop instructions in the form mov rn, rn to be generated using
   1469   // the mov instruction. They must be generated using nop(int/NopMarkerTypes)
   1470   // or MarkCode(int/NopMarkerTypes) pseudo instructions.
   1471   DCHECK(!(src.is_reg() && src.rm().is(dst) && s == LeaveCC && cond == al));
   1472   addrmod1(cond | MOV | s, r0, dst, src);
   1473 }
   1474 
   1475 
   1476 void Assembler::mov_label_offset(Register dst, Label* label) {
   1477   if (label->is_bound()) {
   1478     mov(dst, Operand(label->pos() + (Code::kHeaderSize - kHeapObjectTag)));
   1479   } else {
   1480     // Emit the link to the label in the code stream followed by extra nop
   1481     // instructions.
   1482     // If the label is not linked, then start a new link chain by linking it to
   1483     // itself, emitting pc_offset().
   1484     int link = label->is_linked() ? label->pos() : pc_offset();
   1485     label->link_to(pc_offset());
   1486 
   1487     // When the label is bound, these instructions will be patched with a
   1488     // sequence of movw/movt or mov/orr/orr instructions. They will load the
   1489     // destination register with the position of the label from the beginning
   1490     // of the code.
   1491     //
   1492     // The link will be extracted from the first instruction and the destination
   1493     // register from the second.
   1494     //   For ARMv7:
   1495     //      link
   1496     //      mov dst, dst
   1497     //   For ARMv6:
   1498     //      link
   1499     //      mov dst, dst
   1500     //      mov dst, dst
   1501     //
   1502     // When the label gets bound: target_at extracts the link and target_at_put
   1503     // patches the instructions.
   1504     DCHECK(is_uint24(link));
   1505     BlockConstPoolScope block_const_pool(this);
   1506     emit(link);
   1507     nop(dst.code());
   1508     if (!CpuFeatures::IsSupported(ARMv7)) {
   1509       nop(dst.code());
   1510     }
   1511   }
   1512 }
   1513 
   1514 
   1515 void Assembler::movw(Register reg, uint32_t immediate, Condition cond) {
   1516   DCHECK(CpuFeatures::IsSupported(ARMv7));
   1517   emit(cond | 0x30*B20 | reg.code()*B12 | EncodeMovwImmediate(immediate));
   1518 }
   1519 
   1520 
   1521 void Assembler::movt(Register reg, uint32_t immediate, Condition cond) {
   1522   DCHECK(CpuFeatures::IsSupported(ARMv7));
   1523   emit(cond | 0x34*B20 | reg.code()*B12 | EncodeMovwImmediate(immediate));
   1524 }
   1525 
   1526 
   1527 void Assembler::bic(Register dst, Register src1, const Operand& src2,
   1528                     SBit s, Condition cond) {
   1529   addrmod1(cond | BIC | s, src1, dst, src2);
   1530 }
   1531 
   1532 
   1533 void Assembler::mvn(Register dst, const Operand& src, SBit s, Condition cond) {
   1534   addrmod1(cond | MVN | s, r0, dst, src);
   1535 }
   1536 
   1537 
   1538 // Multiply instructions.
   1539 void Assembler::mla(Register dst, Register src1, Register src2, Register srcA,
   1540                     SBit s, Condition cond) {
   1541   DCHECK(!dst.is(pc) && !src1.is(pc) && !src2.is(pc) && !srcA.is(pc));
   1542   emit(cond | A | s | dst.code()*B16 | srcA.code()*B12 |
   1543        src2.code()*B8 | B7 | B4 | src1.code());
   1544 }
   1545 
   1546 
   1547 void Assembler::mls(Register dst, Register src1, Register src2, Register srcA,
   1548                     Condition cond) {
   1549   DCHECK(!dst.is(pc) && !src1.is(pc) && !src2.is(pc) && !srcA.is(pc));
   1550   DCHECK(IsEnabled(MLS));
   1551   emit(cond | B22 | B21 | dst.code()*B16 | srcA.code()*B12 |
   1552        src2.code()*B8 | B7 | B4 | src1.code());
   1553 }
   1554 
   1555 
   1556 void Assembler::sdiv(Register dst, Register src1, Register src2,
   1557                      Condition cond) {
   1558   DCHECK(!dst.is(pc) && !src1.is(pc) && !src2.is(pc));
   1559   DCHECK(IsEnabled(SUDIV));
   1560   emit(cond | B26 | B25| B24 | B20 | dst.code()*B16 | 0xf * B12 |
   1561        src2.code()*B8 | B4 | src1.code());
   1562 }
   1563 
   1564 
   1565 void Assembler::udiv(Register dst, Register src1, Register src2,
   1566                      Condition cond) {
   1567   DCHECK(!dst.is(pc) && !src1.is(pc) && !src2.is(pc));
   1568   DCHECK(IsEnabled(SUDIV));
   1569   emit(cond | B26 | B25 | B24 | B21 | B20 | dst.code() * B16 | 0xf * B12 |
   1570        src2.code() * B8 | B4 | src1.code());
   1571 }
   1572 
   1573 
   1574 void Assembler::mul(Register dst, Register src1, Register src2,
   1575                     SBit s, Condition cond) {
   1576   DCHECK(!dst.is(pc) && !src1.is(pc) && !src2.is(pc));
   1577   // dst goes in bits 16-19 for this instruction!
   1578   emit(cond | s | dst.code()*B16 | src2.code()*B8 | B7 | B4 | src1.code());
   1579 }
   1580 
   1581 
   1582 void Assembler::smlal(Register dstL,
   1583                       Register dstH,
   1584                       Register src1,
   1585                       Register src2,
   1586                       SBit s,
   1587                       Condition cond) {
   1588   DCHECK(!dstL.is(pc) && !dstH.is(pc) && !src1.is(pc) && !src2.is(pc));
   1589   DCHECK(!dstL.is(dstH));
   1590   emit(cond | B23 | B22 | A | s | dstH.code()*B16 | dstL.code()*B12 |
   1591        src2.code()*B8 | B7 | B4 | src1.code());
   1592 }
   1593 
   1594 
   1595 void Assembler::smull(Register dstL,
   1596                       Register dstH,
   1597                       Register src1,
   1598                       Register src2,
   1599                       SBit s,
   1600                       Condition cond) {
   1601   DCHECK(!dstL.is(pc) && !dstH.is(pc) && !src1.is(pc) && !src2.is(pc));
   1602   DCHECK(!dstL.is(dstH));
   1603   emit(cond | B23 | B22 | s | dstH.code()*B16 | dstL.code()*B12 |
   1604        src2.code()*B8 | B7 | B4 | src1.code());
   1605 }
   1606 
   1607 
   1608 void Assembler::umlal(Register dstL,
   1609                       Register dstH,
   1610                       Register src1,
   1611                       Register src2,
   1612                       SBit s,
   1613                       Condition cond) {
   1614   DCHECK(!dstL.is(pc) && !dstH.is(pc) && !src1.is(pc) && !src2.is(pc));
   1615   DCHECK(!dstL.is(dstH));
   1616   emit(cond | B23 | A | s | dstH.code()*B16 | dstL.code()*B12 |
   1617        src2.code()*B8 | B7 | B4 | src1.code());
   1618 }
   1619 
   1620 
   1621 void Assembler::umull(Register dstL,
   1622                       Register dstH,
   1623                       Register src1,
   1624                       Register src2,
   1625                       SBit s,
   1626                       Condition cond) {
   1627   DCHECK(!dstL.is(pc) && !dstH.is(pc) && !src1.is(pc) && !src2.is(pc));
   1628   DCHECK(!dstL.is(dstH));
   1629   emit(cond | B23 | s | dstH.code()*B16 | dstL.code()*B12 |
   1630        src2.code()*B8 | B7 | B4 | src1.code());
   1631 }
   1632 
   1633 
   1634 // Miscellaneous arithmetic instructions.
   1635 void Assembler::clz(Register dst, Register src, Condition cond) {
   1636   // v5 and above.
   1637   DCHECK(!dst.is(pc) && !src.is(pc));
   1638   emit(cond | B24 | B22 | B21 | 15*B16 | dst.code()*B12 |
   1639        15*B8 | CLZ | src.code());
   1640 }
   1641 
   1642 
   1643 // Saturating instructions.
   1644 
   1645 // Unsigned saturate.
   1646 void Assembler::usat(Register dst,
   1647                      int satpos,
   1648                      const Operand& src,
   1649                      Condition cond) {
   1650   // v6 and above.
   1651   DCHECK(CpuFeatures::IsSupported(ARMv7));
   1652   DCHECK(!dst.is(pc) && !src.rm_.is(pc));
   1653   DCHECK((satpos >= 0) && (satpos <= 31));
   1654   DCHECK((src.shift_op_ == ASR) || (src.shift_op_ == LSL));
   1655   DCHECK(src.rs_.is(no_reg));
   1656 
   1657   int sh = 0;
   1658   if (src.shift_op_ == ASR) {
   1659       sh = 1;
   1660   }
   1661 
   1662   emit(cond | 0x6*B24 | 0xe*B20 | satpos*B16 | dst.code()*B12 |
   1663        src.shift_imm_*B7 | sh*B6 | 0x1*B4 | src.rm_.code());
   1664 }
   1665 
   1666 
   1667 // Bitfield manipulation instructions.
   1668 
   1669 // Unsigned bit field extract.
   1670 // Extracts #width adjacent bits from position #lsb in a register, and
   1671 // writes them to the low bits of a destination register.
   1672 //   ubfx dst, src, #lsb, #width
   1673 void Assembler::ubfx(Register dst,
   1674                      Register src,
   1675                      int lsb,
   1676                      int width,
   1677                      Condition cond) {
   1678   // v7 and above.
   1679   DCHECK(CpuFeatures::IsSupported(ARMv7));
   1680   DCHECK(!dst.is(pc) && !src.is(pc));
   1681   DCHECK((lsb >= 0) && (lsb <= 31));
   1682   DCHECK((width >= 1) && (width <= (32 - lsb)));
   1683   emit(cond | 0xf*B23 | B22 | B21 | (width - 1)*B16 | dst.code()*B12 |
   1684        lsb*B7 | B6 | B4 | src.code());
   1685 }
   1686 
   1687 
   1688 // Signed bit field extract.
   1689 // Extracts #width adjacent bits from position #lsb in a register, and
   1690 // writes them to the low bits of a destination register. The extracted
   1691 // value is sign extended to fill the destination register.
   1692 //   sbfx dst, src, #lsb, #width
   1693 void Assembler::sbfx(Register dst,
   1694                      Register src,
   1695                      int lsb,
   1696                      int width,
   1697                      Condition cond) {
   1698   // v7 and above.
   1699   DCHECK(CpuFeatures::IsSupported(ARMv7));
   1700   DCHECK(!dst.is(pc) && !src.is(pc));
   1701   DCHECK((lsb >= 0) && (lsb <= 31));
   1702   DCHECK((width >= 1) && (width <= (32 - lsb)));
   1703   emit(cond | 0xf*B23 | B21 | (width - 1)*B16 | dst.code()*B12 |
   1704        lsb*B7 | B6 | B4 | src.code());
   1705 }
   1706 
   1707 
   1708 // Bit field clear.
   1709 // Sets #width adjacent bits at position #lsb in the destination register
   1710 // to zero, preserving the value of the other bits.
   1711 //   bfc dst, #lsb, #width
   1712 void Assembler::bfc(Register dst, int lsb, int width, Condition cond) {
   1713   // v7 and above.
   1714   DCHECK(CpuFeatures::IsSupported(ARMv7));
   1715   DCHECK(!dst.is(pc));
   1716   DCHECK((lsb >= 0) && (lsb <= 31));
   1717   DCHECK((width >= 1) && (width <= (32 - lsb)));
   1718   int msb = lsb + width - 1;
   1719   emit(cond | 0x1f*B22 | msb*B16 | dst.code()*B12 | lsb*B7 | B4 | 0xf);
   1720 }
   1721 
   1722 
   1723 // Bit field insert.
   1724 // Inserts #width adjacent bits from the low bits of the source register
   1725 // into position #lsb of the destination register.
   1726 //   bfi dst, src, #lsb, #width
   1727 void Assembler::bfi(Register dst,
   1728                     Register src,
   1729                     int lsb,
   1730                     int width,
   1731                     Condition cond) {
   1732   // v7 and above.
   1733   DCHECK(CpuFeatures::IsSupported(ARMv7));
   1734   DCHECK(!dst.is(pc) && !src.is(pc));
   1735   DCHECK((lsb >= 0) && (lsb <= 31));
   1736   DCHECK((width >= 1) && (width <= (32 - lsb)));
   1737   int msb = lsb + width - 1;
   1738   emit(cond | 0x1f*B22 | msb*B16 | dst.code()*B12 | lsb*B7 | B4 |
   1739        src.code());
   1740 }
   1741 
   1742 
   1743 void Assembler::pkhbt(Register dst,
   1744                       Register src1,
   1745                       const Operand& src2,
   1746                       Condition cond ) {
   1747   // Instruction details available in ARM DDI 0406C.b, A8.8.125.
   1748   // cond(31-28) | 01101000(27-20) | Rn(19-16) |
   1749   // Rd(15-12) | imm5(11-7) | 0(6) | 01(5-4) | Rm(3-0)
   1750   DCHECK(!dst.is(pc));
   1751   DCHECK(!src1.is(pc));
   1752   DCHECK(!src2.rm().is(pc));
   1753   DCHECK(!src2.rm().is(no_reg));
   1754   DCHECK(src2.rs().is(no_reg));
   1755   DCHECK((src2.shift_imm_ >= 0) && (src2.shift_imm_ <= 31));
   1756   DCHECK(src2.shift_op() == LSL);
   1757   emit(cond | 0x68*B20 | src1.code()*B16 | dst.code()*B12 |
   1758        src2.shift_imm_*B7 | B4 | src2.rm().code());
   1759 }
   1760 
   1761 
   1762 void Assembler::pkhtb(Register dst,
   1763                       Register src1,
   1764                       const Operand& src2,
   1765                       Condition cond) {
   1766   // Instruction details available in ARM DDI 0406C.b, A8.8.125.
   1767   // cond(31-28) | 01101000(27-20) | Rn(19-16) |
   1768   // Rd(15-12) | imm5(11-7) | 1(6) | 01(5-4) | Rm(3-0)
   1769   DCHECK(!dst.is(pc));
   1770   DCHECK(!src1.is(pc));
   1771   DCHECK(!src2.rm().is(pc));
   1772   DCHECK(!src2.rm().is(no_reg));
   1773   DCHECK(src2.rs().is(no_reg));
   1774   DCHECK((src2.shift_imm_ >= 1) && (src2.shift_imm_ <= 32));
   1775   DCHECK(src2.shift_op() == ASR);
   1776   int asr = (src2.shift_imm_ == 32) ? 0 : src2.shift_imm_;
   1777   emit(cond | 0x68*B20 | src1.code()*B16 | dst.code()*B12 |
   1778        asr*B7 | B6 | B4 | src2.rm().code());
   1779 }
   1780 
   1781 
   1782 void Assembler::uxtb(Register dst,
   1783                      const Operand& src,
   1784                      Condition cond) {
   1785   // Instruction details available in ARM DDI 0406C.b, A8.8.274.
   1786   // cond(31-28) | 01101110(27-20) | 1111(19-16) |
   1787   // Rd(15-12) | rotate(11-10) | 00(9-8)| 0111(7-4) | Rm(3-0)
   1788   DCHECK(!dst.is(pc));
   1789   DCHECK(!src.rm().is(pc));
   1790   DCHECK(!src.rm().is(no_reg));
   1791   DCHECK(src.rs().is(no_reg));
   1792   DCHECK((src.shift_imm_ == 0) ||
   1793          (src.shift_imm_ == 8) ||
   1794          (src.shift_imm_ == 16) ||
   1795          (src.shift_imm_ == 24));
   1796   // Operand maps ROR #0 to LSL #0.
   1797   DCHECK((src.shift_op() == ROR) ||
   1798          ((src.shift_op() == LSL) && (src.shift_imm_ == 0)));
   1799   emit(cond | 0x6E*B20 | 0xF*B16 | dst.code()*B12 |
   1800        ((src.shift_imm_ >> 1)&0xC)*B8 | 7*B4 | src.rm().code());
   1801 }
   1802 
   1803 
   1804 void Assembler::uxtab(Register dst,
   1805                       Register src1,
   1806                       const Operand& src2,
   1807                       Condition cond) {
   1808   // Instruction details available in ARM DDI 0406C.b, A8.8.271.
   1809   // cond(31-28) | 01101110(27-20) | Rn(19-16) |
   1810   // Rd(15-12) | rotate(11-10) | 00(9-8)| 0111(7-4) | Rm(3-0)
   1811   DCHECK(!dst.is(pc));
   1812   DCHECK(!src1.is(pc));
   1813   DCHECK(!src2.rm().is(pc));
   1814   DCHECK(!src2.rm().is(no_reg));
   1815   DCHECK(src2.rs().is(no_reg));
   1816   DCHECK((src2.shift_imm_ == 0) ||
   1817          (src2.shift_imm_ == 8) ||
   1818          (src2.shift_imm_ == 16) ||
   1819          (src2.shift_imm_ == 24));
   1820   // Operand maps ROR #0 to LSL #0.
   1821   DCHECK((src2.shift_op() == ROR) ||
   1822          ((src2.shift_op() == LSL) && (src2.shift_imm_ == 0)));
   1823   emit(cond | 0x6E*B20 | src1.code()*B16 | dst.code()*B12 |
   1824        ((src2.shift_imm_ >> 1) &0xC)*B8 | 7*B4 | src2.rm().code());
   1825 }
   1826 
   1827 
   1828 void Assembler::uxtb16(Register dst,
   1829                        const Operand& src,
   1830                        Condition cond) {
   1831   // Instruction details available in ARM DDI 0406C.b, A8.8.275.
   1832   // cond(31-28) | 01101100(27-20) | 1111(19-16) |
   1833   // Rd(15-12) | rotate(11-10) | 00(9-8)| 0111(7-4) | Rm(3-0)
   1834   DCHECK(!dst.is(pc));
   1835   DCHECK(!src.rm().is(pc));
   1836   DCHECK(!src.rm().is(no_reg));
   1837   DCHECK(src.rs().is(no_reg));
   1838   DCHECK((src.shift_imm_ == 0) ||
   1839          (src.shift_imm_ == 8) ||
   1840          (src.shift_imm_ == 16) ||
   1841          (src.shift_imm_ == 24));
   1842   // Operand maps ROR #0 to LSL #0.
   1843   DCHECK((src.shift_op() == ROR) ||
   1844          ((src.shift_op() == LSL) && (src.shift_imm_ == 0)));
   1845   emit(cond | 0x6C*B20 | 0xF*B16 | dst.code()*B12 |
   1846        ((src.shift_imm_ >> 1)&0xC)*B8 | 7*B4 | src.rm().code());
   1847 }
   1848 
   1849 
   1850 // Status register access instructions.
   1851 void Assembler::mrs(Register dst, SRegister s, Condition cond) {
   1852   DCHECK(!dst.is(pc));
   1853   emit(cond | B24 | s | 15*B16 | dst.code()*B12);
   1854 }
   1855 
   1856 
   1857 void Assembler::msr(SRegisterFieldMask fields, const Operand& src,
   1858                     Condition cond) {
   1859   DCHECK(fields >= B16 && fields < B20);  // at least one field set
   1860   Instr instr;
   1861   if (!src.rm_.is_valid()) {
   1862     // Immediate.
   1863     uint32_t rotate_imm;
   1864     uint32_t immed_8;
   1865     if (src.must_output_reloc_info(this) ||
   1866         !fits_shifter(src.imm32_, &rotate_imm, &immed_8, NULL)) {
   1867       // Immediate operand cannot be encoded, load it first to register ip.
   1868       move_32_bit_immediate(ip, src);
   1869       msr(fields, Operand(ip), cond);
   1870       return;
   1871     }
   1872     instr = I | rotate_imm*B8 | immed_8;
   1873   } else {
   1874     DCHECK(!src.rs_.is_valid() && src.shift_imm_ == 0);  // only rm allowed
   1875     instr = src.rm_.code();
   1876   }
   1877   emit(cond | instr | B24 | B21 | fields | 15*B12);
   1878 }
   1879 
   1880 
   1881 // Load/Store instructions.
   1882 void Assembler::ldr(Register dst, const MemOperand& src, Condition cond) {
   1883   if (dst.is(pc)) {
   1884     positions_recorder()->WriteRecordedPositions();
   1885   }
   1886   addrmod2(cond | B26 | L, dst, src);
   1887 }
   1888 
   1889 
   1890 void Assembler::str(Register src, const MemOperand& dst, Condition cond) {
   1891   addrmod2(cond | B26, src, dst);
   1892 }
   1893 
   1894 
   1895 void Assembler::ldrb(Register dst, const MemOperand& src, Condition cond) {
   1896   addrmod2(cond | B26 | B | L, dst, src);
   1897 }
   1898 
   1899 
   1900 void Assembler::strb(Register src, const MemOperand& dst, Condition cond) {
   1901   addrmod2(cond | B26 | B, src, dst);
   1902 }
   1903 
   1904 
   1905 void Assembler::ldrh(Register dst, const MemOperand& src, Condition cond) {
   1906   addrmod3(cond | L | B7 | H | B4, dst, src);
   1907 }
   1908 
   1909 
   1910 void Assembler::strh(Register src, const MemOperand& dst, Condition cond) {
   1911   addrmod3(cond | B7 | H | B4, src, dst);
   1912 }
   1913 
   1914 
   1915 void Assembler::ldrsb(Register dst, const MemOperand& src, Condition cond) {
   1916   addrmod3(cond | L | B7 | S6 | B4, dst, src);
   1917 }
   1918 
   1919 
   1920 void Assembler::ldrsh(Register dst, const MemOperand& src, Condition cond) {
   1921   addrmod3(cond | L | B7 | S6 | H | B4, dst, src);
   1922 }
   1923 
   1924 
   1925 void Assembler::ldrd(Register dst1, Register dst2,
   1926                      const MemOperand& src, Condition cond) {
   1927   DCHECK(IsEnabled(ARMv7));
   1928   DCHECK(src.rm().is(no_reg));
   1929   DCHECK(!dst1.is(lr));  // r14.
   1930   DCHECK_EQ(0, dst1.code() % 2);
   1931   DCHECK_EQ(dst1.code() + 1, dst2.code());
   1932   addrmod3(cond | B7 | B6 | B4, dst1, src);
   1933 }
   1934 
   1935 
   1936 void Assembler::strd(Register src1, Register src2,
   1937                      const MemOperand& dst, Condition cond) {
   1938   DCHECK(dst.rm().is(no_reg));
   1939   DCHECK(!src1.is(lr));  // r14.
   1940   DCHECK_EQ(0, src1.code() % 2);
   1941   DCHECK_EQ(src1.code() + 1, src2.code());
   1942   DCHECK(IsEnabled(ARMv7));
   1943   addrmod3(cond | B7 | B6 | B5 | B4, src1, dst);
   1944 }
   1945 
   1946 
   1947 // Preload instructions.
   1948 void Assembler::pld(const MemOperand& address) {
   1949   // Instruction details available in ARM DDI 0406C.b, A8.8.128.
   1950   // 1111(31-28) | 0111(27-24) | U(23) | R(22) | 01(21-20) | Rn(19-16) |
   1951   // 1111(15-12) | imm5(11-07) | type(6-5) | 0(4)| Rm(3-0) |
   1952   DCHECK(address.rm().is(no_reg));
   1953   DCHECK(address.am() == Offset);
   1954   int U = B23;
   1955   int offset = address.offset();
   1956   if (offset < 0) {
   1957     offset = -offset;
   1958     U = 0;
   1959   }
   1960   DCHECK(offset < 4096);
   1961   emit(kSpecialCondition | B26 | B24 | U | B22 | B20 | address.rn().code()*B16 |
   1962        0xf*B12 | offset);
   1963 }
   1964 
   1965 
   1966 // Load/Store multiple instructions.
   1967 void Assembler::ldm(BlockAddrMode am,
   1968                     Register base,
   1969                     RegList dst,
   1970                     Condition cond) {
   1971   // ABI stack constraint: ldmxx base, {..sp..}  base != sp  is not restartable.
   1972   DCHECK(base.is(sp) || (dst & sp.bit()) == 0);
   1973 
   1974   addrmod4(cond | B27 | am | L, base, dst);
   1975 
   1976   // Emit the constant pool after a function return implemented by ldm ..{..pc}.
   1977   if (cond == al && (dst & pc.bit()) != 0) {
   1978     // There is a slight chance that the ldm instruction was actually a call,
   1979     // in which case it would be wrong to return into the constant pool; we
   1980     // recognize this case by checking if the emission of the pool was blocked
   1981     // at the pc of the ldm instruction by a mov lr, pc instruction; if this is
   1982     // the case, we emit a jump over the pool.
   1983     CheckConstPool(true, no_const_pool_before_ == pc_offset() - kInstrSize);
   1984   }
   1985 }
   1986 
   1987 
   1988 void Assembler::stm(BlockAddrMode am,
   1989                     Register base,
   1990                     RegList src,
   1991                     Condition cond) {
   1992   addrmod4(cond | B27 | am, base, src);
   1993 }
   1994 
   1995 
   1996 // Exception-generating instructions and debugging support.
   1997 // Stops with a non-negative code less than kNumOfWatchedStops support
   1998 // enabling/disabling and a counter feature. See simulator-arm.h .
   1999 void Assembler::stop(const char* msg, Condition cond, int32_t code) {
   2000 #ifndef __arm__
   2001   DCHECK(code >= kDefaultStopCode);
   2002   {
   2003     // The Simulator will handle the stop instruction and get the message
   2004     // address. It expects to find the address just after the svc instruction.
   2005     BlockConstPoolScope block_const_pool(this);
   2006     if (code >= 0) {
   2007       svc(kStopCode + code, cond);
   2008     } else {
   2009       svc(kStopCode + kMaxStopCode, cond);
   2010     }
   2011     emit(reinterpret_cast<Instr>(msg));
   2012   }
   2013 #else  // def __arm__
   2014   if (cond != al) {
   2015     Label skip;
   2016     b(&skip, NegateCondition(cond));
   2017     bkpt(0);
   2018     bind(&skip);
   2019   } else {
   2020     bkpt(0);
   2021   }
   2022 #endif  // def __arm__
   2023 }
   2024 
   2025 
   2026 void Assembler::bkpt(uint32_t imm16) {  // v5 and above
   2027   DCHECK(is_uint16(imm16));
   2028   emit(al | B24 | B21 | (imm16 >> 4)*B8 | BKPT | (imm16 & 0xf));
   2029 }
   2030 
   2031 
   2032 void Assembler::svc(uint32_t imm24, Condition cond) {
   2033   DCHECK(is_uint24(imm24));
   2034   emit(cond | 15*B24 | imm24);
   2035 }
   2036 
   2037 
   2038 // Coprocessor instructions.
   2039 void Assembler::cdp(Coprocessor coproc,
   2040                     int opcode_1,
   2041                     CRegister crd,
   2042                     CRegister crn,
   2043                     CRegister crm,
   2044                     int opcode_2,
   2045                     Condition cond) {
   2046   DCHECK(is_uint4(opcode_1) && is_uint3(opcode_2));
   2047   emit(cond | B27 | B26 | B25 | (opcode_1 & 15)*B20 | crn.code()*B16 |
   2048        crd.code()*B12 | coproc*B8 | (opcode_2 & 7)*B5 | crm.code());
   2049 }
   2050 
   2051 
   2052 void Assembler::cdp2(Coprocessor coproc,
   2053                      int opcode_1,
   2054                      CRegister crd,
   2055                      CRegister crn,
   2056                      CRegister crm,
   2057                      int opcode_2) {  // v5 and above
   2058   cdp(coproc, opcode_1, crd, crn, crm, opcode_2, kSpecialCondition);
   2059 }
   2060 
   2061 
   2062 void Assembler::mcr(Coprocessor coproc,
   2063                     int opcode_1,
   2064                     Register rd,
   2065                     CRegister crn,
   2066                     CRegister crm,
   2067                     int opcode_2,
   2068                     Condition cond) {
   2069   DCHECK(is_uint3(opcode_1) && is_uint3(opcode_2));
   2070   emit(cond | B27 | B26 | B25 | (opcode_1 & 7)*B21 | crn.code()*B16 |
   2071        rd.code()*B12 | coproc*B8 | (opcode_2 & 7)*B5 | B4 | crm.code());
   2072 }
   2073 
   2074 
   2075 void Assembler::mcr2(Coprocessor coproc,
   2076                      int opcode_1,
   2077                      Register rd,
   2078                      CRegister crn,
   2079                      CRegister crm,
   2080                      int opcode_2) {  // v5 and above
   2081   mcr(coproc, opcode_1, rd, crn, crm, opcode_2, kSpecialCondition);
   2082 }
   2083 
   2084 
   2085 void Assembler::mrc(Coprocessor coproc,
   2086                     int opcode_1,
   2087                     Register rd,
   2088                     CRegister crn,
   2089                     CRegister crm,
   2090                     int opcode_2,
   2091                     Condition cond) {
   2092   DCHECK(is_uint3(opcode_1) && is_uint3(opcode_2));
   2093   emit(cond | B27 | B26 | B25 | (opcode_1 & 7)*B21 | L | crn.code()*B16 |
   2094        rd.code()*B12 | coproc*B8 | (opcode_2 & 7)*B5 | B4 | crm.code());
   2095 }
   2096 
   2097 
   2098 void Assembler::mrc2(Coprocessor coproc,
   2099                      int opcode_1,
   2100                      Register rd,
   2101                      CRegister crn,
   2102                      CRegister crm,
   2103                      int opcode_2) {  // v5 and above
   2104   mrc(coproc, opcode_1, rd, crn, crm, opcode_2, kSpecialCondition);
   2105 }
   2106 
   2107 
   2108 void Assembler::ldc(Coprocessor coproc,
   2109                     CRegister crd,
   2110                     const MemOperand& src,
   2111                     LFlag l,
   2112                     Condition cond) {
   2113   addrmod5(cond | B27 | B26 | l | L | coproc*B8, crd, src);
   2114 }
   2115 
   2116 
   2117 void Assembler::ldc(Coprocessor coproc,
   2118                     CRegister crd,
   2119                     Register rn,
   2120                     int option,
   2121                     LFlag l,
   2122                     Condition cond) {
   2123   // Unindexed addressing.
   2124   DCHECK(is_uint8(option));
   2125   emit(cond | B27 | B26 | U | l | L | rn.code()*B16 | crd.code()*B12 |
   2126        coproc*B8 | (option & 255));
   2127 }
   2128 
   2129 
   2130 void Assembler::ldc2(Coprocessor coproc,
   2131                      CRegister crd,
   2132                      const MemOperand& src,
   2133                      LFlag l) {  // v5 and above
   2134   ldc(coproc, crd, src, l, kSpecialCondition);
   2135 }
   2136 
   2137 
   2138 void Assembler::ldc2(Coprocessor coproc,
   2139                      CRegister crd,
   2140                      Register rn,
   2141                      int option,
   2142                      LFlag l) {  // v5 and above
   2143   ldc(coproc, crd, rn, option, l, kSpecialCondition);
   2144 }
   2145 
   2146 
   2147 // Support for VFP.
   2148 
   2149 void Assembler::vldr(const DwVfpRegister dst,
   2150                      const Register base,
   2151                      int offset,
   2152                      const Condition cond) {
   2153   // Ddst = MEM(Rbase + offset).
   2154   // Instruction details available in ARM DDI 0406C.b, A8-924.
   2155   // cond(31-28) | 1101(27-24)| U(23) | D(22) | 01(21-20) | Rbase(19-16) |
   2156   // Vd(15-12) | 1011(11-8) | offset
   2157   int u = 1;
   2158   if (offset < 0) {
   2159     offset = -offset;
   2160     u = 0;
   2161   }
   2162   int vd, d;
   2163   dst.split_code(&vd, &d);
   2164 
   2165   DCHECK(offset >= 0);
   2166   if ((offset % 4) == 0 && (offset / 4) < 256) {
   2167     emit(cond | 0xD*B24 | u*B23 | d*B22 | B20 | base.code()*B16 | vd*B12 |
   2168          0xB*B8 | ((offset / 4) & 255));
   2169   } else {
   2170     // Larger offsets must be handled by computing the correct address
   2171     // in the ip register.
   2172     DCHECK(!base.is(ip));
   2173     if (u == 1) {
   2174       add(ip, base, Operand(offset));
   2175     } else {
   2176       sub(ip, base, Operand(offset));
   2177     }
   2178     emit(cond | 0xD*B24 | d*B22 | B20 | ip.code()*B16 | vd*B12 | 0xB*B8);
   2179   }
   2180 }
   2181 
   2182 
   2183 void Assembler::vldr(const DwVfpRegister dst,
   2184                      const MemOperand& operand,
   2185                      const Condition cond) {
   2186   DCHECK(operand.am_ == Offset);
   2187   if (operand.rm().is_valid()) {
   2188     add(ip, operand.rn(),
   2189         Operand(operand.rm(), operand.shift_op_, operand.shift_imm_));
   2190     vldr(dst, ip, 0, cond);
   2191   } else {
   2192     vldr(dst, operand.rn(), operand.offset(), cond);
   2193   }
   2194 }
   2195 
   2196 
   2197 void Assembler::vldr(const SwVfpRegister dst,
   2198                      const Register base,
   2199                      int offset,
   2200                      const Condition cond) {
   2201   // Sdst = MEM(Rbase + offset).
   2202   // Instruction details available in ARM DDI 0406A, A8-628.
   2203   // cond(31-28) | 1101(27-24)| U001(23-20) | Rbase(19-16) |
   2204   // Vdst(15-12) | 1010(11-8) | offset
   2205   int u = 1;
   2206   if (offset < 0) {
   2207     offset = -offset;
   2208     u = 0;
   2209   }
   2210   int sd, d;
   2211   dst.split_code(&sd, &d);
   2212   DCHECK(offset >= 0);
   2213 
   2214   if ((offset % 4) == 0 && (offset / 4) < 256) {
   2215   emit(cond | u*B23 | d*B22 | 0xD1*B20 | base.code()*B16 | sd*B12 |
   2216        0xA*B8 | ((offset / 4) & 255));
   2217   } else {
   2218     // Larger offsets must be handled by computing the correct address
   2219     // in the ip register.
   2220     DCHECK(!base.is(ip));
   2221     if (u == 1) {
   2222       add(ip, base, Operand(offset));
   2223     } else {
   2224       sub(ip, base, Operand(offset));
   2225     }
   2226     emit(cond | d*B22 | 0xD1*B20 | ip.code()*B16 | sd*B12 | 0xA*B8);
   2227   }
   2228 }
   2229 
   2230 
   2231 void Assembler::vldr(const SwVfpRegister dst,
   2232                      const MemOperand& operand,
   2233                      const Condition cond) {
   2234   DCHECK(operand.am_ == Offset);
   2235   if (operand.rm().is_valid()) {
   2236     add(ip, operand.rn(),
   2237         Operand(operand.rm(), operand.shift_op_, operand.shift_imm_));
   2238     vldr(dst, ip, 0, cond);
   2239   } else {
   2240     vldr(dst, operand.rn(), operand.offset(), cond);
   2241   }
   2242 }
   2243 
   2244 
   2245 void Assembler::vstr(const DwVfpRegister src,
   2246                      const Register base,
   2247                      int offset,
   2248                      const Condition cond) {
   2249   // MEM(Rbase + offset) = Dsrc.
   2250   // Instruction details available in ARM DDI 0406C.b, A8-1082.
   2251   // cond(31-28) | 1101(27-24)| U(23) | D(22) | 00(21-20) | Rbase(19-16) |
   2252   // Vd(15-12) | 1011(11-8) | (offset/4)
   2253   int u = 1;
   2254   if (offset < 0) {
   2255     offset = -offset;
   2256     u = 0;
   2257   }
   2258   DCHECK(offset >= 0);
   2259   int vd, d;
   2260   src.split_code(&vd, &d);
   2261 
   2262   if ((offset % 4) == 0 && (offset / 4) < 256) {
   2263     emit(cond | 0xD*B24 | u*B23 | d*B22 | base.code()*B16 | vd*B12 | 0xB*B8 |
   2264          ((offset / 4) & 255));
   2265   } else {
   2266     // Larger offsets must be handled by computing the correct address
   2267     // in the ip register.
   2268     DCHECK(!base.is(ip));
   2269     if (u == 1) {
   2270       add(ip, base, Operand(offset));
   2271     } else {
   2272       sub(ip, base, Operand(offset));
   2273     }
   2274     emit(cond | 0xD*B24 | d*B22 | ip.code()*B16 | vd*B12 | 0xB*B8);
   2275   }
   2276 }
   2277 
   2278 
   2279 void Assembler::vstr(const DwVfpRegister src,
   2280                      const MemOperand& operand,
   2281                      const Condition cond) {
   2282   DCHECK(operand.am_ == Offset);
   2283   if (operand.rm().is_valid()) {
   2284     add(ip, operand.rn(),
   2285         Operand(operand.rm(), operand.shift_op_, operand.shift_imm_));
   2286     vstr(src, ip, 0, cond);
   2287   } else {
   2288     vstr(src, operand.rn(), operand.offset(), cond);
   2289   }
   2290 }
   2291 
   2292 
   2293 void Assembler::vstr(const SwVfpRegister src,
   2294                      const Register base,
   2295                      int offset,
   2296                      const Condition cond) {
   2297   // MEM(Rbase + offset) = SSrc.
   2298   // Instruction details available in ARM DDI 0406A, A8-786.
   2299   // cond(31-28) | 1101(27-24)| U000(23-20) | Rbase(19-16) |
   2300   // Vdst(15-12) | 1010(11-8) | (offset/4)
   2301   int u = 1;
   2302   if (offset < 0) {
   2303     offset = -offset;
   2304     u = 0;
   2305   }
   2306   int sd, d;
   2307   src.split_code(&sd, &d);
   2308   DCHECK(offset >= 0);
   2309   if ((offset % 4) == 0 && (offset / 4) < 256) {
   2310     emit(cond | u*B23 | d*B22 | 0xD0*B20 | base.code()*B16 | sd*B12 |
   2311          0xA*B8 | ((offset / 4) & 255));
   2312   } else {
   2313     // Larger offsets must be handled by computing the correct address
   2314     // in the ip register.
   2315     DCHECK(!base.is(ip));
   2316     if (u == 1) {
   2317       add(ip, base, Operand(offset));
   2318     } else {
   2319       sub(ip, base, Operand(offset));
   2320     }
   2321     emit(cond | d*B22 | 0xD0*B20 | ip.code()*B16 | sd*B12 | 0xA*B8);
   2322   }
   2323 }
   2324 
   2325 
   2326 void Assembler::vstr(const SwVfpRegister src,
   2327                      const MemOperand& operand,
   2328                      const Condition cond) {
   2329   DCHECK(operand.am_ == Offset);
   2330   if (operand.rm().is_valid()) {
   2331     add(ip, operand.rn(),
   2332         Operand(operand.rm(), operand.shift_op_, operand.shift_imm_));
   2333     vstr(src, ip, 0, cond);
   2334   } else {
   2335     vstr(src, operand.rn(), operand.offset(), cond);
   2336   }
   2337 }
   2338 
   2339 
   2340 void  Assembler::vldm(BlockAddrMode am,
   2341                       Register base,
   2342                       DwVfpRegister first,
   2343                       DwVfpRegister last,
   2344                       Condition cond) {
   2345   // Instruction details available in ARM DDI 0406C.b, A8-922.
   2346   // cond(31-28) | 110(27-25)| PUDW1(24-20) | Rbase(19-16) |
   2347   // first(15-12) | 1011(11-8) | (count * 2)
   2348   DCHECK_LE(first.code(), last.code());
   2349   DCHECK(am == ia || am == ia_w || am == db_w);
   2350   DCHECK(!base.is(pc));
   2351 
   2352   int sd, d;
   2353   first.split_code(&sd, &d);
   2354   int count = last.code() - first.code() + 1;
   2355   DCHECK(count <= 16);
   2356   emit(cond | B27 | B26 | am | d*B22 | B20 | base.code()*B16 | sd*B12 |
   2357        0xB*B8 | count*2);
   2358 }
   2359 
   2360 
   2361 void  Assembler::vstm(BlockAddrMode am,
   2362                       Register base,
   2363                       DwVfpRegister first,
   2364                       DwVfpRegister last,
   2365                       Condition cond) {
   2366   // Instruction details available in ARM DDI 0406C.b, A8-1080.
   2367   // cond(31-28) | 110(27-25)| PUDW0(24-20) | Rbase(19-16) |
   2368   // first(15-12) | 1011(11-8) | (count * 2)
   2369   DCHECK_LE(first.code(), last.code());
   2370   DCHECK(am == ia || am == ia_w || am == db_w);
   2371   DCHECK(!base.is(pc));
   2372 
   2373   int sd, d;
   2374   first.split_code(&sd, &d);
   2375   int count = last.code() - first.code() + 1;
   2376   DCHECK(count <= 16);
   2377   emit(cond | B27 | B26 | am | d*B22 | base.code()*B16 | sd*B12 |
   2378        0xB*B8 | count*2);
   2379 }
   2380 
   2381 void  Assembler::vldm(BlockAddrMode am,
   2382                       Register base,
   2383                       SwVfpRegister first,
   2384                       SwVfpRegister last,
   2385                       Condition cond) {
   2386   // Instruction details available in ARM DDI 0406A, A8-626.
   2387   // cond(31-28) | 110(27-25)| PUDW1(24-20) | Rbase(19-16) |
   2388   // first(15-12) | 1010(11-8) | (count/2)
   2389   DCHECK_LE(first.code(), last.code());
   2390   DCHECK(am == ia || am == ia_w || am == db_w);
   2391   DCHECK(!base.is(pc));
   2392 
   2393   int sd, d;
   2394   first.split_code(&sd, &d);
   2395   int count = last.code() - first.code() + 1;
   2396   emit(cond | B27 | B26 | am | d*B22 | B20 | base.code()*B16 | sd*B12 |
   2397        0xA*B8 | count);
   2398 }
   2399 
   2400 
   2401 void  Assembler::vstm(BlockAddrMode am,
   2402                       Register base,
   2403                       SwVfpRegister first,
   2404                       SwVfpRegister last,
   2405                       Condition cond) {
   2406   // Instruction details available in ARM DDI 0406A, A8-784.
   2407   // cond(31-28) | 110(27-25)| PUDW0(24-20) | Rbase(19-16) |
   2408   // first(15-12) | 1011(11-8) | (count/2)
   2409   DCHECK_LE(first.code(), last.code());
   2410   DCHECK(am == ia || am == ia_w || am == db_w);
   2411   DCHECK(!base.is(pc));
   2412 
   2413   int sd, d;
   2414   first.split_code(&sd, &d);
   2415   int count = last.code() - first.code() + 1;
   2416   emit(cond | B27 | B26 | am | d*B22 | base.code()*B16 | sd*B12 |
   2417        0xA*B8 | count);
   2418 }
   2419 
   2420 
   2421 static void DoubleAsTwoUInt32(double d, uint32_t* lo, uint32_t* hi) {
   2422   uint64_t i;
   2423   memcpy(&i, &d, 8);
   2424 
   2425   *lo = i & 0xffffffff;
   2426   *hi = i >> 32;
   2427 }
   2428 
   2429 
   2430 // Only works for little endian floating point formats.
   2431 // We don't support VFP on the mixed endian floating point platform.
   2432 static bool FitsVMOVDoubleImmediate(double d, uint32_t *encoding) {
   2433   DCHECK(CpuFeatures::IsSupported(VFP3));
   2434 
   2435   // VMOV can accept an immediate of the form:
   2436   //
   2437   //  +/- m * 2^(-n) where 16 <= m <= 31 and 0 <= n <= 7
   2438   //
   2439   // The immediate is encoded using an 8-bit quantity, comprised of two
   2440   // 4-bit fields. For an 8-bit immediate of the form:
   2441   //
   2442   //  [abcdefgh]
   2443   //
   2444   // where a is the MSB and h is the LSB, an immediate 64-bit double can be
   2445   // created of the form:
   2446   //
   2447   //  [aBbbbbbb,bbcdefgh,00000000,00000000,
   2448   //      00000000,00000000,00000000,00000000]
   2449   //
   2450   // where B = ~b.
   2451   //
   2452 
   2453   uint32_t lo, hi;
   2454   DoubleAsTwoUInt32(d, &lo, &hi);
   2455 
   2456   // The most obvious constraint is the long block of zeroes.
   2457   if ((lo != 0) || ((hi & 0xffff) != 0)) {
   2458     return false;
   2459   }
   2460 
   2461   // Bits 62:55 must be all clear or all set.
   2462   if (((hi & 0x3fc00000) != 0) && ((hi & 0x3fc00000) != 0x3fc00000)) {
   2463     return false;
   2464   }
   2465 
   2466   // Bit 63 must be NOT bit 62.
   2467   if (((hi ^ (hi << 1)) & (0x40000000)) == 0) {
   2468     return false;
   2469   }
   2470 
   2471   // Create the encoded immediate in the form:
   2472   //  [00000000,0000abcd,00000000,0000efgh]
   2473   *encoding  = (hi >> 16) & 0xf;      // Low nybble.
   2474   *encoding |= (hi >> 4) & 0x70000;   // Low three bits of the high nybble.
   2475   *encoding |= (hi >> 12) & 0x80000;  // Top bit of the high nybble.
   2476 
   2477   return true;
   2478 }
   2479 
   2480 
   2481 void Assembler::vmov(const DwVfpRegister dst,
   2482                      double imm,
   2483                      const Register scratch) {
   2484   uint32_t enc;
   2485   if (CpuFeatures::IsSupported(VFP3) && FitsVMOVDoubleImmediate(imm, &enc)) {
   2486     // The double can be encoded in the instruction.
   2487     //
   2488     // Dd = immediate
   2489     // Instruction details available in ARM DDI 0406C.b, A8-936.
   2490     // cond(31-28) | 11101(27-23) | D(22) | 11(21-20) | imm4H(19-16) |
   2491     // Vd(15-12) | 101(11-9) | sz=1(8) | imm4L(3-0)
   2492     int vd, d;
   2493     dst.split_code(&vd, &d);
   2494     emit(al | 0x1D*B23 | d*B22 | 0x3*B20 | vd*B12 | 0x5*B9 | B8 | enc);
   2495   } else if (FLAG_enable_vldr_imm && is_constant_pool_available()) {
   2496     // TODO(jfb) Temporarily turned off until we have constant blinding or
   2497     //           some equivalent mitigation: an attacker can otherwise control
   2498     //           generated data which also happens to be executable, a Very Bad
   2499     //           Thing indeed.
   2500     //           Blinding gets tricky because we don't have xor, we probably
   2501     //           need to add/subtract without losing precision, which requires a
   2502     //           cookie value that Lithium is probably better positioned to
   2503     //           choose.
   2504     //           We could also add a few peepholes here like detecting 0.0 and
   2505     //           -0.0 and doing a vmov from the sequestered d14, forcing denorms
   2506     //           to zero (we set flush-to-zero), and normalizing NaN values.
   2507     //           We could also detect redundant values.
   2508     //           The code could also randomize the order of values, though
   2509     //           that's tricky because vldr has a limited reach. Furthermore
   2510     //           it breaks load locality.
   2511     RelocInfo rinfo(pc_, imm);
   2512     ConstantPoolArray::LayoutSection section = ConstantPoolAddEntry(rinfo);
   2513     if (section == ConstantPoolArray::EXTENDED_SECTION) {
   2514       DCHECK(FLAG_enable_ool_constant_pool);
   2515       // Emit instructions to load constant pool offset.
   2516       movw(ip, 0);
   2517       movt(ip, 0);
   2518       // Load from constant pool at offset.
   2519       vldr(dst, MemOperand(pp, ip));
   2520     } else {
   2521       DCHECK(section == ConstantPoolArray::SMALL_SECTION);
   2522       vldr(dst, MemOperand(FLAG_enable_ool_constant_pool ? pp : pc, 0));
   2523     }
   2524   } else {
   2525     // Synthesise the double from ARM immediates.
   2526     uint32_t lo, hi;
   2527     DoubleAsTwoUInt32(imm, &lo, &hi);
   2528 
   2529     if (scratch.is(no_reg)) {
   2530       if (dst.code() < 16) {
   2531         const LowDwVfpRegister loc = LowDwVfpRegister::from_code(dst.code());
   2532         // Move the low part of the double into the lower of the corresponsing S
   2533         // registers of D register dst.
   2534         mov(ip, Operand(lo));
   2535         vmov(loc.low(), ip);
   2536 
   2537         // Move the high part of the double into the higher of the
   2538         // corresponsing S registers of D register dst.
   2539         mov(ip, Operand(hi));
   2540         vmov(loc.high(), ip);
   2541       } else {
   2542         // D16-D31 does not have S registers, so move the low and high parts
   2543         // directly to the D register using vmov.32.
   2544         // Note: This may be slower, so we only do this when we have to.
   2545         mov(ip, Operand(lo));
   2546         vmov(dst, VmovIndexLo, ip);
   2547         mov(ip, Operand(hi));
   2548         vmov(dst, VmovIndexHi, ip);
   2549       }
   2550     } else {
   2551       // Move the low and high parts of the double to a D register in one
   2552       // instruction.
   2553       mov(ip, Operand(lo));
   2554       mov(scratch, Operand(hi));
   2555       vmov(dst, ip, scratch);
   2556     }
   2557   }
   2558 }
   2559 
   2560 
   2561 void Assembler::vmov(const SwVfpRegister dst,
   2562                      const SwVfpRegister src,
   2563                      const Condition cond) {
   2564   // Sd = Sm
   2565   // Instruction details available in ARM DDI 0406B, A8-642.
   2566   int sd, d, sm, m;
   2567   dst.split_code(&sd, &d);
   2568   src.split_code(&sm, &m);
   2569   emit(cond | 0xE*B24 | d*B22 | 0xB*B20 | sd*B12 | 0xA*B8 | B6 | m*B5 | sm);
   2570 }
   2571 
   2572 
   2573 void Assembler::vmov(const DwVfpRegister dst,
   2574                      const DwVfpRegister src,
   2575                      const Condition cond) {
   2576   // Dd = Dm
   2577   // Instruction details available in ARM DDI 0406C.b, A8-938.
   2578   // cond(31-28) | 11101(27-23) | D(22) | 11(21-20) | 0000(19-16) | Vd(15-12) |
   2579   // 101(11-9) | sz=1(8) | 0(7) | 1(6) | M(5) | 0(4) | Vm(3-0)
   2580   int vd, d;
   2581   dst.split_code(&vd, &d);
   2582   int vm, m;
   2583   src.split_code(&vm, &m);
   2584   emit(cond | 0x1D*B23 | d*B22 | 0x3*B20 | vd*B12 | 0x5*B9 | B8 | B6 | m*B5 |
   2585        vm);
   2586 }
   2587 
   2588 
   2589 void Assembler::vmov(const DwVfpRegister dst,
   2590                      const VmovIndex index,
   2591                      const Register src,
   2592                      const Condition cond) {
   2593   // Dd[index] = Rt
   2594   // Instruction details available in ARM DDI 0406C.b, A8-940.
   2595   // cond(31-28) | 1110(27-24) | 0(23) | opc1=0index(22-21) | 0(20) |
   2596   // Vd(19-16) | Rt(15-12) | 1011(11-8) | D(7) | opc2=00(6-5) | 1(4) | 0000(3-0)
   2597   DCHECK(index.index == 0 || index.index == 1);
   2598   int vd, d;
   2599   dst.split_code(&vd, &d);
   2600   emit(cond | 0xE*B24 | index.index*B21 | vd*B16 | src.code()*B12 | 0xB*B8 |
   2601        d*B7 | B4);
   2602 }
   2603 
   2604 
   2605 void Assembler::vmov(const Register dst,
   2606                      const VmovIndex index,
   2607                      const DwVfpRegister src,
   2608                      const Condition cond) {
   2609   // Dd[index] = Rt
   2610   // Instruction details available in ARM DDI 0406C.b, A8.8.342.
   2611   // cond(31-28) | 1110(27-24) | U=0(23) | opc1=0index(22-21) | 1(20) |
   2612   // Vn(19-16) | Rt(15-12) | 1011(11-8) | N(7) | opc2=00(6-5) | 1(4) | 0000(3-0)
   2613   DCHECK(index.index == 0 || index.index == 1);
   2614   int vn, n;
   2615   src.split_code(&vn, &n);
   2616   emit(cond | 0xE*B24 | index.index*B21 | B20 | vn*B16 | dst.code()*B12 |
   2617        0xB*B8 | n*B7 | B4);
   2618 }
   2619 
   2620 
   2621 void Assembler::vmov(const DwVfpRegister dst,
   2622                      const Register src1,
   2623                      const Register src2,
   2624                      const Condition cond) {
   2625   // Dm = <Rt,Rt2>.
   2626   // Instruction details available in ARM DDI 0406C.b, A8-948.
   2627   // cond(31-28) | 1100(27-24)| 010(23-21) | op=0(20) | Rt2(19-16) |
   2628   // Rt(15-12) | 1011(11-8) | 00(7-6) | M(5) | 1(4) | Vm
   2629   DCHECK(!src1.is(pc) && !src2.is(pc));
   2630   int vm, m;
   2631   dst.split_code(&vm, &m);
   2632   emit(cond | 0xC*B24 | B22 | src2.code()*B16 |
   2633        src1.code()*B12 | 0xB*B8 | m*B5 | B4 | vm);
   2634 }
   2635 
   2636 
   2637 void Assembler::vmov(const Register dst1,
   2638                      const Register dst2,
   2639                      const DwVfpRegister src,
   2640                      const Condition cond) {
   2641   // <Rt,Rt2> = Dm.
   2642   // Instruction details available in ARM DDI 0406C.b, A8-948.
   2643   // cond(31-28) | 1100(27-24)| 010(23-21) | op=1(20) | Rt2(19-16) |
   2644   // Rt(15-12) | 1011(11-8) | 00(7-6) | M(5) | 1(4) | Vm
   2645   DCHECK(!dst1.is(pc) && !dst2.is(pc));
   2646   int vm, m;
   2647   src.split_code(&vm, &m);
   2648   emit(cond | 0xC*B24 | B22 | B20 | dst2.code()*B16 |
   2649        dst1.code()*B12 | 0xB*B8 | m*B5 | B4 | vm);
   2650 }
   2651 
   2652 
   2653 void Assembler::vmov(const SwVfpRegister dst,
   2654                      const Register src,
   2655                      const Condition cond) {
   2656   // Sn = Rt.
   2657   // Instruction details available in ARM DDI 0406A, A8-642.
   2658   // cond(31-28) | 1110(27-24)| 000(23-21) | op=0(20) | Vn(19-16) |
   2659   // Rt(15-12) | 1010(11-8) | N(7)=0 | 00(6-5) | 1(4) | 0000(3-0)
   2660   DCHECK(!src.is(pc));
   2661   int sn, n;
   2662   dst.split_code(&sn, &n);
   2663   emit(cond | 0xE*B24 | sn*B16 | src.code()*B12 | 0xA*B8 | n*B7 | B4);
   2664 }
   2665 
   2666 
   2667 void Assembler::vmov(const Register dst,
   2668                      const SwVfpRegister src,
   2669                      const Condition cond) {
   2670   // Rt = Sn.
   2671   // Instruction details available in ARM DDI 0406A, A8-642.
   2672   // cond(31-28) | 1110(27-24)| 000(23-21) | op=1(20) | Vn(19-16) |
   2673   // Rt(15-12) | 1010(11-8) | N(7)=0 | 00(6-5) | 1(4) | 0000(3-0)
   2674   DCHECK(!dst.is(pc));
   2675   int sn, n;
   2676   src.split_code(&sn, &n);
   2677   emit(cond | 0xE*B24 | B20 | sn*B16 | dst.code()*B12 | 0xA*B8 | n*B7 | B4);
   2678 }
   2679 
   2680 
   2681 // Type of data to read from or write to VFP register.
   2682 // Used as specifier in generic vcvt instruction.
   2683 enum VFPType { S32, U32, F32, F64 };
   2684 
   2685 
   2686 static bool IsSignedVFPType(VFPType type) {
   2687   switch (type) {
   2688     case S32:
   2689       return true;
   2690     case U32:
   2691       return false;
   2692     default:
   2693       UNREACHABLE();
   2694       return false;
   2695   }
   2696 }
   2697 
   2698 
   2699 static bool IsIntegerVFPType(VFPType type) {
   2700   switch (type) {
   2701     case S32:
   2702     case U32:
   2703       return true;
   2704     case F32:
   2705     case F64:
   2706       return false;
   2707     default:
   2708       UNREACHABLE();
   2709       return false;
   2710   }
   2711 }
   2712 
   2713 
   2714 static bool IsDoubleVFPType(VFPType type) {
   2715   switch (type) {
   2716     case F32:
   2717       return false;
   2718     case F64:
   2719       return true;
   2720     default:
   2721       UNREACHABLE();
   2722       return false;
   2723   }
   2724 }
   2725 
   2726 
   2727 // Split five bit reg_code based on size of reg_type.
   2728 //  32-bit register codes are Vm:M
   2729 //  64-bit register codes are M:Vm
   2730 // where Vm is four bits, and M is a single bit.
   2731 static void SplitRegCode(VFPType reg_type,
   2732                          int reg_code,
   2733                          int* vm,
   2734                          int* m) {
   2735   DCHECK((reg_code >= 0) && (reg_code <= 31));
   2736   if (IsIntegerVFPType(reg_type) || !IsDoubleVFPType(reg_type)) {
   2737     // 32 bit type.
   2738     *m  = reg_code & 0x1;
   2739     *vm = reg_code >> 1;
   2740   } else {
   2741     // 64 bit type.
   2742     *m  = (reg_code & 0x10) >> 4;
   2743     *vm = reg_code & 0x0F;
   2744   }
   2745 }
   2746 
   2747 
   2748 // Encode vcvt.src_type.dst_type instruction.
   2749 static Instr EncodeVCVT(const VFPType dst_type,
   2750                         const int dst_code,
   2751                         const VFPType src_type,
   2752                         const int src_code,
   2753                         VFPConversionMode mode,
   2754                         const Condition cond) {
   2755   DCHECK(src_type != dst_type);
   2756   int D, Vd, M, Vm;
   2757   SplitRegCode(src_type, src_code, &Vm, &M);
   2758   SplitRegCode(dst_type, dst_code, &Vd, &D);
   2759 
   2760   if (IsIntegerVFPType(dst_type) || IsIntegerVFPType(src_type)) {
   2761     // Conversion between IEEE floating point and 32-bit integer.
   2762     // Instruction details available in ARM DDI 0406B, A8.6.295.
   2763     // cond(31-28) | 11101(27-23)| D(22) | 11(21-20) | 1(19) | opc2(18-16) |
   2764     // Vd(15-12) | 101(11-9) | sz(8) | op(7) | 1(6) | M(5) | 0(4) | Vm(3-0)
   2765     DCHECK(!IsIntegerVFPType(dst_type) || !IsIntegerVFPType(src_type));
   2766 
   2767     int sz, opc2, op;
   2768 
   2769     if (IsIntegerVFPType(dst_type)) {
   2770       opc2 = IsSignedVFPType(dst_type) ? 0x5 : 0x4;
   2771       sz = IsDoubleVFPType(src_type) ? 0x1 : 0x0;
   2772       op = mode;
   2773     } else {
   2774       DCHECK(IsIntegerVFPType(src_type));
   2775       opc2 = 0x0;
   2776       sz = IsDoubleVFPType(dst_type) ? 0x1 : 0x0;
   2777       op = IsSignedVFPType(src_type) ? 0x1 : 0x0;
   2778     }
   2779 
   2780     return (cond | 0xE*B24 | B23 | D*B22 | 0x3*B20 | B19 | opc2*B16 |
   2781             Vd*B12 | 0x5*B9 | sz*B8 | op*B7 | B6 | M*B5 | Vm);
   2782   } else {
   2783     // Conversion between IEEE double and single precision.
   2784     // Instruction details available in ARM DDI 0406B, A8.6.298.
   2785     // cond(31-28) | 11101(27-23)| D(22) | 11(21-20) | 0111(19-16) |
   2786     // Vd(15-12) | 101(11-9) | sz(8) | 1(7) | 1(6) | M(5) | 0(4) | Vm(3-0)
   2787     int sz = IsDoubleVFPType(src_type) ? 0x1 : 0x0;
   2788     return (cond | 0xE*B24 | B23 | D*B22 | 0x3*B20 | 0x7*B16 |
   2789             Vd*B12 | 0x5*B9 | sz*B8 | B7 | B6 | M*B5 | Vm);
   2790   }
   2791 }
   2792 
   2793 
   2794 void Assembler::vcvt_f64_s32(const DwVfpRegister dst,
   2795                              const SwVfpRegister src,
   2796                              VFPConversionMode mode,
   2797                              const Condition cond) {
   2798   emit(EncodeVCVT(F64, dst.code(), S32, src.code(), mode, cond));
   2799 }
   2800 
   2801 
   2802 void Assembler::vcvt_f32_s32(const SwVfpRegister dst,
   2803                              const SwVfpRegister src,
   2804                              VFPConversionMode mode,
   2805                              const Condition cond) {
   2806   emit(EncodeVCVT(F32, dst.code(), S32, src.code(), mode, cond));
   2807 }
   2808 
   2809 
   2810 void Assembler::vcvt_f64_u32(const DwVfpRegister dst,
   2811                              const SwVfpRegister src,
   2812                              VFPConversionMode mode,
   2813                              const Condition cond) {
   2814   emit(EncodeVCVT(F64, dst.code(), U32, src.code(), mode, cond));
   2815 }
   2816 
   2817 
   2818 void Assembler::vcvt_s32_f64(const SwVfpRegister dst,
   2819                              const DwVfpRegister src,
   2820                              VFPConversionMode mode,
   2821                              const Condition cond) {
   2822   emit(EncodeVCVT(S32, dst.code(), F64, src.code(), mode, cond));
   2823 }
   2824 
   2825 
   2826 void Assembler::vcvt_u32_f64(const SwVfpRegister dst,
   2827                              const DwVfpRegister src,
   2828                              VFPConversionMode mode,
   2829                              const Condition cond) {
   2830   emit(EncodeVCVT(U32, dst.code(), F64, src.code(), mode, cond));
   2831 }
   2832 
   2833 
   2834 void Assembler::vcvt_f64_f32(const DwVfpRegister dst,
   2835                              const SwVfpRegister src,
   2836                              VFPConversionMode mode,
   2837                              const Condition cond) {
   2838   emit(EncodeVCVT(F64, dst.code(), F32, src.code(), mode, cond));
   2839 }
   2840 
   2841 
   2842 void Assembler::vcvt_f32_f64(const SwVfpRegister dst,
   2843                              const DwVfpRegister src,
   2844                              VFPConversionMode mode,
   2845                              const Condition cond) {
   2846   emit(EncodeVCVT(F32, dst.code(), F64, src.code(), mode, cond));
   2847 }
   2848 
   2849 
   2850 void Assembler::vcvt_f64_s32(const DwVfpRegister dst,
   2851                              int fraction_bits,
   2852                              const Condition cond) {
   2853   // Instruction details available in ARM DDI 0406C.b, A8-874.
   2854   // cond(31-28) | 11101(27-23) | D(22) | 11(21-20) | 1010(19-16) | Vd(15-12) |
   2855   // 101(11-9) | sf=1(8) | sx=1(7) | 1(6) | i(5) | 0(4) | imm4(3-0)
   2856   DCHECK(fraction_bits > 0 && fraction_bits <= 32);
   2857   DCHECK(CpuFeatures::IsSupported(VFP3));
   2858   int vd, d;
   2859   dst.split_code(&vd, &d);
   2860   int imm5 = 32 - fraction_bits;
   2861   int i = imm5 & 1;
   2862   int imm4 = (imm5 >> 1) & 0xf;
   2863   emit(cond | 0xE*B24 | B23 | d*B22 | 0x3*B20 | B19 | 0x2*B16 |
   2864        vd*B12 | 0x5*B9 | B8 | B7 | B6 | i*B5 | imm4);
   2865 }
   2866 
   2867 
   2868 void Assembler::vneg(const DwVfpRegister dst,
   2869                      const DwVfpRegister src,
   2870                      const Condition cond) {
   2871   // Instruction details available in ARM DDI 0406C.b, A8-968.
   2872   // cond(31-28) | 11101(27-23) | D(22) | 11(21-20) | 0001(19-16) | Vd(15-12) |
   2873   // 101(11-9) | sz=1(8) | 0(7) | 1(6) | M(5) | 0(4) | Vm(3-0)
   2874   int vd, d;
   2875   dst.split_code(&vd, &d);
   2876   int vm, m;
   2877   src.split_code(&vm, &m);
   2878 
   2879   emit(cond | 0x1D*B23 | d*B22 | 0x3*B20 | B16 | vd*B12 | 0x5*B9 | B8 | B6 |
   2880        m*B5 | vm);
   2881 }
   2882 
   2883 
   2884 void Assembler::vabs(const DwVfpRegister dst,
   2885                      const DwVfpRegister src,
   2886                      const Condition cond) {
   2887   // Instruction details available in ARM DDI 0406C.b, A8-524.
   2888   // cond(31-28) | 11101(27-23) | D(22) | 11(21-20) | 0000(19-16) | Vd(15-12) |
   2889   // 101(11-9) | sz=1(8) | 1(7) | 1(6) | M(5) | 0(4) | Vm(3-0)
   2890   int vd, d;
   2891   dst.split_code(&vd, &d);
   2892   int vm, m;
   2893   src.split_code(&vm, &m);
   2894   emit(cond | 0x1D*B23 | d*B22 | 0x3*B20 | vd*B12 | 0x5*B9 | B8 | B7 | B6 |
   2895        m*B5 | vm);
   2896 }
   2897 
   2898 
   2899 void Assembler::vadd(const DwVfpRegister dst,
   2900                      const DwVfpRegister src1,
   2901                      const DwVfpRegister src2,
   2902                      const Condition cond) {
   2903   // Dd = vadd(Dn, Dm) double precision floating point addition.
   2904   // Dd = D:Vd; Dm=M:Vm; Dn=N:Vm.
   2905   // Instruction details available in ARM DDI 0406C.b, A8-830.
   2906   // cond(31-28) | 11100(27-23)| D(22) | 11(21-20) | Vn(19-16) |
   2907   // Vd(15-12) | 101(11-9) | sz=1(8) | N(7) | 0(6) | M(5) | 0(4) | Vm(3-0)
   2908   int vd, d;
   2909   dst.split_code(&vd, &d);
   2910   int vn, n;
   2911   src1.split_code(&vn, &n);
   2912   int vm, m;
   2913   src2.split_code(&vm, &m);
   2914   emit(cond | 0x1C*B23 | d*B22 | 0x3*B20 | vn*B16 | vd*B12 | 0x5*B9 | B8 |
   2915        n*B7 | m*B5 | vm);
   2916 }
   2917 
   2918 
   2919 void Assembler::vsub(const DwVfpRegister dst,
   2920                      const DwVfpRegister src1,
   2921                      const DwVfpRegister src2,
   2922                      const Condition cond) {
   2923   // Dd = vsub(Dn, Dm) double precision floating point subtraction.
   2924   // Dd = D:Vd; Dm=M:Vm; Dn=N:Vm.
   2925   // Instruction details available in ARM DDI 0406C.b, A8-1086.
   2926   // cond(31-28) | 11100(27-23)| D(22) | 11(21-20) | Vn(19-16) |
   2927   // Vd(15-12) | 101(11-9) | sz=1(8) | N(7) | 1(6) | M(5) | 0(4) | Vm(3-0)
   2928   int vd, d;
   2929   dst.split_code(&vd, &d);
   2930   int vn, n;
   2931   src1.split_code(&vn, &n);
   2932   int vm, m;
   2933   src2.split_code(&vm, &m);
   2934   emit(cond | 0x1C*B23 | d*B22 | 0x3*B20 | vn*B16 | vd*B12 | 0x5*B9 | B8 |
   2935        n*B7 | B6 | m*B5 | vm);
   2936 }
   2937 
   2938 
   2939 void Assembler::vmul(const DwVfpRegister dst,
   2940                      const DwVfpRegister src1,
   2941                      const DwVfpRegister src2,
   2942                      const Condition cond) {
   2943   // Dd = vmul(Dn, Dm) double precision floating point multiplication.
   2944   // Dd = D:Vd; Dm=M:Vm; Dn=N:Vm.
   2945   // Instruction details available in ARM DDI 0406C.b, A8-960.
   2946   // cond(31-28) | 11100(27-23)| D(22) | 10(21-20) | Vn(19-16) |
   2947   // Vd(15-12) | 101(11-9) | sz=1(8) | N(7) | 0(6) | M(5) | 0(4) | Vm(3-0)
   2948   int vd, d;
   2949   dst.split_code(&vd, &d);
   2950   int vn, n;
   2951   src1.split_code(&vn, &n);
   2952   int vm, m;
   2953   src2.split_code(&vm, &m);
   2954   emit(cond | 0x1C*B23 | d*B22 | 0x2*B20 | vn*B16 | vd*B12 | 0x5*B9 | B8 |
   2955        n*B7 | m*B5 | vm);
   2956 }
   2957 
   2958 
   2959 void Assembler::vmla(const DwVfpRegister dst,
   2960                      const DwVfpRegister src1,
   2961                      const DwVfpRegister src2,
   2962                      const Condition cond) {
   2963   // Instruction details available in ARM DDI 0406C.b, A8-932.
   2964   // cond(31-28) | 11100(27-23) | D(22) | 00(21-20) | Vn(19-16) |
   2965   // Vd(15-12) | 101(11-9) | sz=1(8) | N(7) | op=0(6) | M(5) | 0(4) | Vm(3-0)
   2966   int vd, d;
   2967   dst.split_code(&vd, &d);
   2968   int vn, n;
   2969   src1.split_code(&vn, &n);
   2970   int vm, m;
   2971   src2.split_code(&vm, &m);
   2972   emit(cond | 0x1C*B23 | d*B22 | vn*B16 | vd*B12 | 0x5*B9 | B8 | n*B7 | m*B5 |
   2973        vm);
   2974 }
   2975 
   2976 
   2977 void Assembler::vmls(const DwVfpRegister dst,
   2978                      const DwVfpRegister src1,
   2979                      const DwVfpRegister src2,
   2980                      const Condition cond) {
   2981   // Instruction details available in ARM DDI 0406C.b, A8-932.
   2982   // cond(31-28) | 11100(27-23) | D(22) | 00(21-20) | Vn(19-16) |
   2983   // Vd(15-12) | 101(11-9) | sz=1(8) | N(7) | op=1(6) | M(5) | 0(4) | Vm(3-0)
   2984   int vd, d;
   2985   dst.split_code(&vd, &d);
   2986   int vn, n;
   2987   src1.split_code(&vn, &n);
   2988   int vm, m;
   2989   src2.split_code(&vm, &m);
   2990   emit(cond | 0x1C*B23 | d*B22 | vn*B16 | vd*B12 | 0x5*B9 | B8 | n*B7 | B6 |
   2991        m*B5 | vm);
   2992 }
   2993 
   2994 
   2995 void Assembler::vdiv(const DwVfpRegister dst,
   2996                      const DwVfpRegister src1,
   2997                      const DwVfpRegister src2,
   2998                      const Condition cond) {
   2999   // Dd = vdiv(Dn, Dm) double precision floating point division.
   3000   // Dd = D:Vd; Dm=M:Vm; Dn=N:Vm.
   3001   // Instruction details available in ARM DDI 0406C.b, A8-882.
   3002   // cond(31-28) | 11101(27-23)| D(22) | 00(21-20) | Vn(19-16) |
   3003   // Vd(15-12) | 101(11-9) | sz=1(8) | N(7) | 0(6) | M(5) | 0(4) | Vm(3-0)
   3004   int vd, d;
   3005   dst.split_code(&vd, &d);
   3006   int vn, n;
   3007   src1.split_code(&vn, &n);
   3008   int vm, m;
   3009   src2.split_code(&vm, &m);
   3010   emit(cond | 0x1D*B23 | d*B22 | vn*B16 | vd*B12 | 0x5*B9 | B8 | n*B7 | m*B5 |
   3011        vm);
   3012 }
   3013 
   3014 
   3015 void Assembler::vcmp(const DwVfpRegister src1,
   3016                      const DwVfpRegister src2,
   3017                      const Condition cond) {
   3018   // vcmp(Dd, Dm) double precision floating point comparison.
   3019   // Instruction details available in ARM DDI 0406C.b, A8-864.
   3020   // cond(31-28) | 11101(27-23)| D(22) | 11(21-20) | 0100(19-16) |
   3021   // Vd(15-12) | 101(11-9) | sz=1(8) | E=0(7) | 1(6) | M(5) | 0(4) | Vm(3-0)
   3022   int vd, d;
   3023   src1.split_code(&vd, &d);
   3024   int vm, m;
   3025   src2.split_code(&vm, &m);
   3026   emit(cond | 0x1D*B23 | d*B22 | 0x3*B20 | 0x4*B16 | vd*B12 | 0x5*B9 | B8 | B6 |
   3027        m*B5 | vm);
   3028 }
   3029 
   3030 
   3031 void Assembler::vcmp(const DwVfpRegister src1,
   3032                      const double src2,
   3033                      const Condition cond) {
   3034   // vcmp(Dd, #0.0) double precision floating point comparison.
   3035   // Instruction details available in ARM DDI 0406C.b, A8-864.
   3036   // cond(31-28) | 11101(27-23)| D(22) | 11(21-20) | 0101(19-16) |
   3037   // Vd(15-12) | 101(11-9) | sz=1(8) | E=0(7) | 1(6) | 0(5) | 0(4) | 0000(3-0)
   3038   DCHECK(src2 == 0.0);
   3039   int vd, d;
   3040   src1.split_code(&vd, &d);
   3041   emit(cond | 0x1D*B23 | d*B22 | 0x3*B20 | 0x5*B16 | vd*B12 | 0x5*B9 | B8 | B6);
   3042 }
   3043 
   3044 
   3045 void Assembler::vmsr(Register dst, Condition cond) {
   3046   // Instruction details available in ARM DDI 0406A, A8-652.
   3047   // cond(31-28) | 1110 (27-24) | 1110(23-20)| 0001 (19-16) |
   3048   // Rt(15-12) | 1010 (11-8) | 0(7) | 00 (6-5) | 1(4) | 0000(3-0)
   3049   emit(cond | 0xE*B24 | 0xE*B20 |  B16 |
   3050        dst.code()*B12 | 0xA*B8 | B4);
   3051 }
   3052 
   3053 
   3054 void Assembler::vmrs(Register dst, Condition cond) {
   3055   // Instruction details available in ARM DDI 0406A, A8-652.
   3056   // cond(31-28) | 1110 (27-24) | 1111(23-20)| 0001 (19-16) |
   3057   // Rt(15-12) | 1010 (11-8) | 0(7) | 00 (6-5) | 1(4) | 0000(3-0)
   3058   emit(cond | 0xE*B24 | 0xF*B20 |  B16 |
   3059        dst.code()*B12 | 0xA*B8 | B4);
   3060 }
   3061 
   3062 
   3063 void Assembler::vsqrt(const DwVfpRegister dst,
   3064                       const DwVfpRegister src,
   3065                       const Condition cond) {
   3066   // Instruction details available in ARM DDI 0406C.b, A8-1058.
   3067   // cond(31-28) | 11101(27-23)| D(22) | 11(21-20) | 0001(19-16) |
   3068   // Vd(15-12) | 101(11-9) | sz=1(8) | 11(7-6) | M(5) | 0(4) | Vm(3-0)
   3069   int vd, d;
   3070   dst.split_code(&vd, &d);
   3071   int vm, m;
   3072   src.split_code(&vm, &m);
   3073   emit(cond | 0x1D*B23 | d*B22 | 0x3*B20 | B16 | vd*B12 | 0x5*B9 | B8 | 0x3*B6 |
   3074        m*B5 | vm);
   3075 }
   3076 
   3077 
   3078 // Support for NEON.
   3079 
   3080 void Assembler::vld1(NeonSize size,
   3081                      const NeonListOperand& dst,
   3082                      const NeonMemOperand& src) {
   3083   // Instruction details available in ARM DDI 0406C.b, A8.8.320.
   3084   // 1111(31-28) | 01000(27-23) | D(22) | 10(21-20) | Rn(19-16) |
   3085   // Vd(15-12) | type(11-8) | size(7-6) | align(5-4) | Rm(3-0)
   3086   DCHECK(CpuFeatures::IsSupported(NEON));
   3087   int vd, d;
   3088   dst.base().split_code(&vd, &d);
   3089   emit(0xFU*B28 | 4*B24 | d*B22 | 2*B20 | src.rn().code()*B16 | vd*B12 |
   3090        dst.type()*B8 | size*B6 | src.align()*B4 | src.rm().code());
   3091 }
   3092 
   3093 
   3094 void Assembler::vst1(NeonSize size,
   3095                      const NeonListOperand& src,
   3096                      const NeonMemOperand& dst) {
   3097   // Instruction details available in ARM DDI 0406C.b, A8.8.404.
   3098   // 1111(31-28) | 01000(27-23) | D(22) | 00(21-20) | Rn(19-16) |
   3099   // Vd(15-12) | type(11-8) | size(7-6) | align(5-4) | Rm(3-0)
   3100   DCHECK(CpuFeatures::IsSupported(NEON));
   3101   int vd, d;
   3102   src.base().split_code(&vd, &d);
   3103   emit(0xFU*B28 | 4*B24 | d*B22 | dst.rn().code()*B16 | vd*B12 | src.type()*B8 |
   3104        size*B6 | dst.align()*B4 | dst.rm().code());
   3105 }
   3106 
   3107 
   3108 void Assembler::vmovl(NeonDataType dt, QwNeonRegister dst, DwVfpRegister src) {
   3109   // Instruction details available in ARM DDI 0406C.b, A8.8.346.
   3110   // 1111(31-28) | 001(27-25) | U(24) | 1(23) | D(22) | imm3(21-19) |
   3111   // 000(18-16) | Vd(15-12) | 101000(11-6) | M(5) | 1(4) | Vm(3-0)
   3112   DCHECK(CpuFeatures::IsSupported(NEON));
   3113   int vd, d;
   3114   dst.split_code(&vd, &d);
   3115   int vm, m;
   3116   src.split_code(&vm, &m);
   3117   emit(0xFU*B28 | B25 | (dt & NeonDataTypeUMask) | B23 | d*B22 |
   3118         (dt & NeonDataTypeSizeMask)*B19 | vd*B12 | 0xA*B8 | m*B5 | B4 | vm);
   3119 }
   3120 
   3121 
   3122 // Pseudo instructions.
   3123 void Assembler::nop(int type) {
   3124   // ARMv6{K/T2} and v7 have an actual NOP instruction but it serializes
   3125   // some of the CPU's pipeline and has to issue. Older ARM chips simply used
   3126   // MOV Rx, Rx as NOP and it performs better even in newer CPUs.
   3127   // We therefore use MOV Rx, Rx, even on newer CPUs, and use Rx to encode
   3128   // a type.
   3129   DCHECK(0 <= type && type <= 14);  // mov pc, pc isn't a nop.
   3130   emit(al | 13*B21 | type*B12 | type);
   3131 }
   3132 
   3133 
   3134 bool Assembler::IsMovT(Instr instr) {
   3135   instr &= ~(((kNumberOfConditions - 1) << 28) |  // Mask off conditions
   3136              ((kNumRegisters-1)*B12) |            // mask out register
   3137              EncodeMovwImmediate(0xFFFF));        // mask out immediate value
   3138   return instr == kMovtPattern;
   3139 }
   3140 
   3141 
   3142 bool Assembler::IsMovW(Instr instr) {
   3143   instr &= ~(((kNumberOfConditions - 1) << 28) |  // Mask off conditions
   3144              ((kNumRegisters-1)*B12) |            // mask out destination
   3145              EncodeMovwImmediate(0xFFFF));        // mask out immediate value
   3146   return instr == kMovwPattern;
   3147 }
   3148 
   3149 
   3150 Instr Assembler::GetMovTPattern() { return kMovtPattern; }
   3151 
   3152 
   3153 Instr Assembler::GetMovWPattern() { return kMovwPattern; }
   3154 
   3155 
   3156 Instr Assembler::EncodeMovwImmediate(uint32_t immediate) {
   3157   DCHECK(immediate < 0x10000);
   3158   return ((immediate & 0xf000) << 4) | (immediate & 0xfff);
   3159 }
   3160 
   3161 
   3162 Instr Assembler::PatchMovwImmediate(Instr instruction, uint32_t immediate) {
   3163   instruction &= ~EncodeMovwImmediate(0xffff);
   3164   return instruction | EncodeMovwImmediate(immediate);
   3165 }
   3166 
   3167 
   3168 int Assembler::DecodeShiftImm(Instr instr) {
   3169   int rotate = Instruction::RotateValue(instr) * 2;
   3170   int immed8 = Instruction::Immed8Value(instr);
   3171   return (immed8 >> rotate) | (immed8 << (32 - rotate));
   3172 }
   3173 
   3174 
   3175 Instr Assembler::PatchShiftImm(Instr instr, int immed) {
   3176   uint32_t rotate_imm = 0;
   3177   uint32_t immed_8 = 0;
   3178   bool immed_fits = fits_shifter(immed, &rotate_imm, &immed_8, NULL);
   3179   DCHECK(immed_fits);
   3180   USE(immed_fits);
   3181   return (instr & ~kOff12Mask) | (rotate_imm << 8) | immed_8;
   3182 }
   3183 
   3184 
   3185 bool Assembler::IsNop(Instr instr, int type) {
   3186   DCHECK(0 <= type && type <= 14);  // mov pc, pc isn't a nop.
   3187   // Check for mov rx, rx where x = type.
   3188   return instr == (al | 13*B21 | type*B12 | type);
   3189 }
   3190 
   3191 
   3192 bool Assembler::IsMovImmed(Instr instr) {
   3193   return (instr & kMovImmedMask) == kMovImmedPattern;
   3194 }
   3195 
   3196 
   3197 bool Assembler::IsOrrImmed(Instr instr) {
   3198   return (instr & kOrrImmedMask) == kOrrImmedPattern;
   3199 }
   3200 
   3201 
   3202 // static
   3203 bool Assembler::ImmediateFitsAddrMode1Instruction(int32_t imm32) {
   3204   uint32_t dummy1;
   3205   uint32_t dummy2;
   3206   return fits_shifter(imm32, &dummy1, &dummy2, NULL);
   3207 }
   3208 
   3209 
   3210 bool Assembler::ImmediateFitsAddrMode2Instruction(int32_t imm32) {
   3211   return is_uint12(abs(imm32));
   3212 }
   3213 
   3214 
   3215 // Debugging.
   3216 void Assembler::RecordJSReturn() {
   3217   positions_recorder()->WriteRecordedPositions();
   3218   CheckBuffer();
   3219   RecordRelocInfo(RelocInfo::JS_RETURN);
   3220 }
   3221 
   3222 
   3223 void Assembler::RecordDebugBreakSlot() {
   3224   positions_recorder()->WriteRecordedPositions();
   3225   CheckBuffer();
   3226   RecordRelocInfo(RelocInfo::DEBUG_BREAK_SLOT);
   3227 }
   3228 
   3229 
   3230 void Assembler::RecordComment(const char* msg) {
   3231   if (FLAG_code_comments) {
   3232     CheckBuffer();
   3233     RecordRelocInfo(RelocInfo::COMMENT, reinterpret_cast<intptr_t>(msg));
   3234   }
   3235 }
   3236 
   3237 
   3238 void Assembler::RecordConstPool(int size) {
   3239   // We only need this for debugger support, to correctly compute offsets in the
   3240   // code.
   3241   RecordRelocInfo(RelocInfo::CONST_POOL, static_cast<intptr_t>(size));
   3242 }
   3243 
   3244 
   3245 void Assembler::GrowBuffer() {
   3246   if (!own_buffer_) FATAL("external code buffer is too small");
   3247 
   3248   // Compute new buffer size.
   3249   CodeDesc desc;  // the new buffer
   3250   if (buffer_size_ < 1 * MB) {
   3251     desc.buffer_size = 2*buffer_size_;
   3252   } else {
   3253     desc.buffer_size = buffer_size_ + 1*MB;
   3254   }
   3255   CHECK_GT(desc.buffer_size, 0);  // no overflow
   3256 
   3257   // Set up new buffer.
   3258   desc.buffer = NewArray<byte>(desc.buffer_size);
   3259 
   3260   desc.instr_size = pc_offset();
   3261   desc.reloc_size = (buffer_ + buffer_size_) - reloc_info_writer.pos();
   3262 
   3263   // Copy the data.
   3264   int pc_delta = desc.buffer - buffer_;
   3265   int rc_delta = (desc.buffer + desc.buffer_size) - (buffer_ + buffer_size_);
   3266   MemMove(desc.buffer, buffer_, desc.instr_size);
   3267   MemMove(reloc_info_writer.pos() + rc_delta, reloc_info_writer.pos(),
   3268           desc.reloc_size);
   3269 
   3270   // Switch buffers.
   3271   DeleteArray(buffer_);
   3272   buffer_ = desc.buffer;
   3273   buffer_size_ = desc.buffer_size;
   3274   pc_ += pc_delta;
   3275   reloc_info_writer.Reposition(reloc_info_writer.pos() + rc_delta,
   3276                                reloc_info_writer.last_pc() + pc_delta);
   3277 
   3278   // None of our relocation types are pc relative pointing outside the code
   3279   // buffer nor pc absolute pointing inside the code buffer, so there is no need
   3280   // to relocate any emitted relocation entries.
   3281 
   3282   // Relocate pending relocation entries.
   3283   for (int i = 0; i < num_pending_32_bit_reloc_info_; i++) {
   3284     RelocInfo& rinfo = pending_32_bit_reloc_info_[i];
   3285     DCHECK(rinfo.rmode() != RelocInfo::COMMENT &&
   3286            rinfo.rmode() != RelocInfo::POSITION);
   3287     if (rinfo.rmode() != RelocInfo::JS_RETURN) {
   3288       rinfo.set_pc(rinfo.pc() + pc_delta);
   3289     }
   3290   }
   3291   for (int i = 0; i < num_pending_64_bit_reloc_info_; i++) {
   3292     RelocInfo& rinfo = pending_64_bit_reloc_info_[i];
   3293     DCHECK(rinfo.rmode() == RelocInfo::NONE64);
   3294     rinfo.set_pc(rinfo.pc() + pc_delta);
   3295   }
   3296   constant_pool_builder_.Relocate(pc_delta);
   3297 }
   3298 
   3299 
   3300 void Assembler::db(uint8_t data) {
   3301   // No relocation info should be pending while using db. db is used
   3302   // to write pure data with no pointers and the constant pool should
   3303   // be emitted before using db.
   3304   DCHECK(num_pending_32_bit_reloc_info_ == 0);
   3305   DCHECK(num_pending_64_bit_reloc_info_ == 0);
   3306   CheckBuffer();
   3307   *reinterpret_cast<uint8_t*>(pc_) = data;
   3308   pc_ += sizeof(uint8_t);
   3309 }
   3310 
   3311 
   3312 void Assembler::dd(uint32_t data) {
   3313   // No relocation info should be pending while using dd. dd is used
   3314   // to write pure data with no pointers and the constant pool should
   3315   // be emitted before using dd.
   3316   DCHECK(num_pending_32_bit_reloc_info_ == 0);
   3317   DCHECK(num_pending_64_bit_reloc_info_ == 0);
   3318   CheckBuffer();
   3319   *reinterpret_cast<uint32_t*>(pc_) = data;
   3320   pc_ += sizeof(uint32_t);
   3321 }
   3322 
   3323 
   3324 void Assembler::emit_code_stub_address(Code* stub) {
   3325   CheckBuffer();
   3326   *reinterpret_cast<uint32_t*>(pc_) =
   3327       reinterpret_cast<uint32_t>(stub->instruction_start());
   3328   pc_ += sizeof(uint32_t);
   3329 }
   3330 
   3331 
   3332 void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
   3333   RelocInfo rinfo(pc_, rmode, data, NULL);
   3334   RecordRelocInfo(rinfo);
   3335 }
   3336 
   3337 
   3338 void Assembler::RecordRelocInfo(const RelocInfo& rinfo) {
   3339   if (!RelocInfo::IsNone(rinfo.rmode())) {
   3340     // Don't record external references unless the heap will be serialized.
   3341     if (rinfo.rmode() == RelocInfo::EXTERNAL_REFERENCE &&
   3342         !serializer_enabled() && !emit_debug_code()) {
   3343       return;
   3344     }
   3345     DCHECK(buffer_space() >= kMaxRelocSize);  // too late to grow buffer here
   3346     if (rinfo.rmode() == RelocInfo::CODE_TARGET_WITH_ID) {
   3347       RelocInfo reloc_info_with_ast_id(rinfo.pc(),
   3348                                        rinfo.rmode(),
   3349                                        RecordedAstId().ToInt(),
   3350                                        NULL);
   3351       ClearRecordedAstId();
   3352       reloc_info_writer.Write(&reloc_info_with_ast_id);
   3353     } else {
   3354       reloc_info_writer.Write(&rinfo);
   3355     }
   3356   }
   3357 }
   3358 
   3359 
   3360 ConstantPoolArray::LayoutSection Assembler::ConstantPoolAddEntry(
   3361     const RelocInfo& rinfo) {
   3362   if (FLAG_enable_ool_constant_pool) {
   3363     return constant_pool_builder_.AddEntry(this, rinfo);
   3364   } else {
   3365     if (rinfo.rmode() == RelocInfo::NONE64) {
   3366       DCHECK(num_pending_64_bit_reloc_info_ < kMaxNumPending64RelocInfo);
   3367       if (num_pending_64_bit_reloc_info_ == 0) {
   3368         first_const_pool_64_use_ = pc_offset();
   3369       }
   3370       pending_64_bit_reloc_info_[num_pending_64_bit_reloc_info_++] = rinfo;
   3371     } else {
   3372       DCHECK(num_pending_32_bit_reloc_info_ < kMaxNumPending32RelocInfo);
   3373       if (num_pending_32_bit_reloc_info_ == 0) {
   3374         first_const_pool_32_use_ = pc_offset();
   3375       }
   3376       pending_32_bit_reloc_info_[num_pending_32_bit_reloc_info_++] = rinfo;
   3377     }
   3378     // Make sure the constant pool is not emitted in place of the next
   3379     // instruction for which we just recorded relocation info.
   3380     BlockConstPoolFor(1);
   3381     return ConstantPoolArray::SMALL_SECTION;
   3382   }
   3383 }
   3384 
   3385 
   3386 void Assembler::BlockConstPoolFor(int instructions) {
   3387   if (FLAG_enable_ool_constant_pool) {
   3388     // Should be a no-op if using an out-of-line constant pool.
   3389     DCHECK(num_pending_32_bit_reloc_info_ == 0);
   3390     DCHECK(num_pending_64_bit_reloc_info_ == 0);
   3391     return;
   3392   }
   3393 
   3394   int pc_limit = pc_offset() + instructions * kInstrSize;
   3395   if (no_const_pool_before_ < pc_limit) {
   3396     // Max pool start (if we need a jump and an alignment).
   3397 #ifdef DEBUG
   3398     int start = pc_limit + kInstrSize + 2 * kPointerSize;
   3399     DCHECK((num_pending_32_bit_reloc_info_ == 0) ||
   3400            (start - first_const_pool_32_use_ +
   3401             num_pending_64_bit_reloc_info_ * kDoubleSize < kMaxDistToIntPool));
   3402     DCHECK((num_pending_64_bit_reloc_info_ == 0) ||
   3403            (start - first_const_pool_64_use_ < kMaxDistToFPPool));
   3404 #endif
   3405     no_const_pool_before_ = pc_limit;
   3406   }
   3407 
   3408   if (next_buffer_check_ < no_const_pool_before_) {
   3409     next_buffer_check_ = no_const_pool_before_;
   3410   }
   3411 }
   3412 
   3413 
   3414 void Assembler::CheckConstPool(bool force_emit, bool require_jump) {
   3415   if (FLAG_enable_ool_constant_pool) {
   3416     // Should be a no-op if using an out-of-line constant pool.
   3417     DCHECK(num_pending_32_bit_reloc_info_ == 0);
   3418     DCHECK(num_pending_64_bit_reloc_info_ == 0);
   3419     return;
   3420   }
   3421 
   3422   // Some short sequence of instruction mustn't be broken up by constant pool
   3423   // emission, such sequences are protected by calls to BlockConstPoolFor and
   3424   // BlockConstPoolScope.
   3425   if (is_const_pool_blocked()) {
   3426     // Something is wrong if emission is forced and blocked at the same time.
   3427     DCHECK(!force_emit);
   3428     return;
   3429   }
   3430 
   3431   // There is nothing to do if there are no pending constant pool entries.
   3432   if ((num_pending_32_bit_reloc_info_ == 0) &&
   3433       (num_pending_64_bit_reloc_info_ == 0)) {
   3434     // Calculate the offset of the next check.
   3435     next_buffer_check_ = pc_offset() + kCheckPoolInterval;
   3436     return;
   3437   }
   3438 
   3439   // Check that the code buffer is large enough before emitting the constant
   3440   // pool (include the jump over the pool and the constant pool marker and
   3441   // the gap to the relocation information).
   3442   int jump_instr = require_jump ? kInstrSize : 0;
   3443   int size_up_to_marker = jump_instr + kInstrSize;
   3444   int size_after_marker = num_pending_32_bit_reloc_info_ * kPointerSize;
   3445   bool has_fp_values = (num_pending_64_bit_reloc_info_ > 0);
   3446   bool require_64_bit_align = false;
   3447   if (has_fp_values) {
   3448     require_64_bit_align = (((uintptr_t)pc_ + size_up_to_marker) & 0x7);
   3449     if (require_64_bit_align) {
   3450       size_after_marker += kInstrSize;
   3451     }
   3452     size_after_marker += num_pending_64_bit_reloc_info_ * kDoubleSize;
   3453   }
   3454 
   3455   int size = size_up_to_marker + size_after_marker;
   3456 
   3457   // We emit a constant pool when:
   3458   //  * requested to do so by parameter force_emit (e.g. after each function).
   3459   //  * the distance from the first instruction accessing the constant pool to
   3460   //    any of the constant pool entries will exceed its limit the next
   3461   //    time the pool is checked. This is overly restrictive, but we don't emit
   3462   //    constant pool entries in-order so it's conservatively correct.
   3463   //  * the instruction doesn't require a jump after itself to jump over the
   3464   //    constant pool, and we're getting close to running out of range.
   3465   if (!force_emit) {
   3466     DCHECK((first_const_pool_32_use_ >= 0) || (first_const_pool_64_use_ >= 0));
   3467     bool need_emit = false;
   3468     if (has_fp_values) {
   3469       int dist64 = pc_offset() +
   3470                    size -
   3471                    num_pending_32_bit_reloc_info_ * kPointerSize -
   3472                    first_const_pool_64_use_;
   3473       if ((dist64 >= kMaxDistToFPPool - kCheckPoolInterval) ||
   3474           (!require_jump && (dist64 >= kMaxDistToFPPool / 2))) {
   3475         need_emit = true;
   3476       }
   3477     }
   3478     int dist32 =
   3479       pc_offset() + size - first_const_pool_32_use_;
   3480     if ((dist32 >= kMaxDistToIntPool - kCheckPoolInterval) ||
   3481         (!require_jump && (dist32 >= kMaxDistToIntPool / 2))) {
   3482       need_emit = true;
   3483     }
   3484     if (!need_emit) return;
   3485   }
   3486 
   3487   int needed_space = size + kGap;
   3488   while (buffer_space() <= needed_space) GrowBuffer();
   3489 
   3490   {
   3491     // Block recursive calls to CheckConstPool.
   3492     BlockConstPoolScope block_const_pool(this);
   3493     RecordComment("[ Constant Pool");
   3494     RecordConstPool(size);
   3495 
   3496     // Emit jump over constant pool if necessary.
   3497     Label after_pool;
   3498     if (require_jump) {
   3499       b(&after_pool);
   3500     }
   3501 
   3502     // Put down constant pool marker "Undefined instruction".
   3503     // The data size helps disassembly know what to print.
   3504     emit(kConstantPoolMarker |
   3505          EncodeConstantPoolLength(size_after_marker / kPointerSize));
   3506 
   3507     if (require_64_bit_align) {
   3508       emit(kConstantPoolMarker);
   3509     }
   3510 
   3511     // Emit 64-bit constant pool entries first: their range is smaller than
   3512     // 32-bit entries.
   3513     for (int i = 0; i < num_pending_64_bit_reloc_info_; i++) {
   3514       RelocInfo& rinfo = pending_64_bit_reloc_info_[i];
   3515 
   3516       DCHECK(!((uintptr_t)pc_ & 0x7));  // Check 64-bit alignment.
   3517 
   3518       Instr instr = instr_at(rinfo.pc());
   3519       // Instruction to patch must be 'vldr rd, [pc, #offset]' with offset == 0.
   3520       DCHECK((IsVldrDPcImmediateOffset(instr) &&
   3521               GetVldrDRegisterImmediateOffset(instr) == 0));
   3522 
   3523       int delta = pc_ - rinfo.pc() - kPcLoadDelta;
   3524       DCHECK(is_uint10(delta));
   3525 
   3526       bool found = false;
   3527       uint64_t value = rinfo.raw_data64();
   3528       for (int j = 0; j < i; j++) {
   3529         RelocInfo& rinfo2 = pending_64_bit_reloc_info_[j];
   3530         if (value == rinfo2.raw_data64()) {
   3531           found = true;
   3532           DCHECK(rinfo2.rmode() == RelocInfo::NONE64);
   3533           Instr instr2 = instr_at(rinfo2.pc());
   3534           DCHECK(IsVldrDPcImmediateOffset(instr2));
   3535           delta = GetVldrDRegisterImmediateOffset(instr2);
   3536           delta += rinfo2.pc() - rinfo.pc();
   3537           break;
   3538         }
   3539       }
   3540 
   3541       instr_at_put(rinfo.pc(), SetVldrDRegisterImmediateOffset(instr, delta));
   3542 
   3543       if (!found) {
   3544         uint64_t uint_data = rinfo.raw_data64();
   3545         emit(uint_data & 0xFFFFFFFF);
   3546         emit(uint_data >> 32);
   3547       }
   3548     }
   3549 
   3550     // Emit 32-bit constant pool entries.
   3551     for (int i = 0; i < num_pending_32_bit_reloc_info_; i++) {
   3552       RelocInfo& rinfo = pending_32_bit_reloc_info_[i];
   3553       DCHECK(rinfo.rmode() != RelocInfo::COMMENT &&
   3554              rinfo.rmode() != RelocInfo::POSITION &&
   3555              rinfo.rmode() != RelocInfo::STATEMENT_POSITION &&
   3556              rinfo.rmode() != RelocInfo::CONST_POOL &&
   3557              rinfo.rmode() != RelocInfo::NONE64);
   3558 
   3559       Instr instr = instr_at(rinfo.pc());
   3560 
   3561       // 64-bit loads shouldn't get here.
   3562       DCHECK(!IsVldrDPcImmediateOffset(instr));
   3563 
   3564       if (IsLdrPcImmediateOffset(instr) &&
   3565           GetLdrRegisterImmediateOffset(instr) == 0) {
   3566         int delta = pc_ - rinfo.pc() - kPcLoadDelta;
   3567         DCHECK(is_uint12(delta));
   3568         // 0 is the smallest delta:
   3569         //   ldr rd, [pc, #0]
   3570         //   constant pool marker
   3571         //   data
   3572 
   3573         bool found = false;
   3574         if (!serializer_enabled() && rinfo.rmode() >= RelocInfo::CELL) {
   3575           for (int j = 0; j < i; j++) {
   3576             RelocInfo& rinfo2 = pending_32_bit_reloc_info_[j];
   3577 
   3578             if ((rinfo2.data() == rinfo.data()) &&
   3579                 (rinfo2.rmode() == rinfo.rmode())) {
   3580               Instr instr2 = instr_at(rinfo2.pc());
   3581               if (IsLdrPcImmediateOffset(instr2)) {
   3582                 delta = GetLdrRegisterImmediateOffset(instr2);
   3583                 delta += rinfo2.pc() - rinfo.pc();
   3584                 found = true;
   3585                 break;
   3586               }
   3587             }
   3588           }
   3589         }
   3590 
   3591         instr_at_put(rinfo.pc(), SetLdrRegisterImmediateOffset(instr, delta));
   3592 
   3593         if (!found) {
   3594           emit(rinfo.data());
   3595         }
   3596       } else {
   3597         DCHECK(IsMovW(instr));
   3598       }
   3599     }
   3600 
   3601     num_pending_32_bit_reloc_info_ = 0;
   3602     num_pending_64_bit_reloc_info_ = 0;
   3603     first_const_pool_32_use_ = -1;
   3604     first_const_pool_64_use_ = -1;
   3605 
   3606     RecordComment("]");
   3607 
   3608     if (after_pool.is_linked()) {
   3609       bind(&after_pool);
   3610     }
   3611   }
   3612 
   3613   // Since a constant pool was just emitted, move the check offset forward by
   3614   // the standard interval.
   3615   next_buffer_check_ = pc_offset() + kCheckPoolInterval;
   3616 }
   3617 
   3618 
   3619 Handle<ConstantPoolArray> Assembler::NewConstantPool(Isolate* isolate) {
   3620   if (!FLAG_enable_ool_constant_pool) {
   3621     return isolate->factory()->empty_constant_pool_array();
   3622   }
   3623   return constant_pool_builder_.New(isolate);
   3624 }
   3625 
   3626 
   3627 void Assembler::PopulateConstantPool(ConstantPoolArray* constant_pool) {
   3628   constant_pool_builder_.Populate(this, constant_pool);
   3629 }
   3630 
   3631 
   3632 ConstantPoolBuilder::ConstantPoolBuilder()
   3633     : entries_(), current_section_(ConstantPoolArray::SMALL_SECTION) {}
   3634 
   3635 
   3636 bool ConstantPoolBuilder::IsEmpty() {
   3637   return entries_.size() == 0;
   3638 }
   3639 
   3640 
   3641 ConstantPoolArray::Type ConstantPoolBuilder::GetConstantPoolType(
   3642     RelocInfo::Mode rmode) {
   3643   if (rmode == RelocInfo::NONE64) {
   3644     return ConstantPoolArray::INT64;
   3645   } else if (!RelocInfo::IsGCRelocMode(rmode)) {
   3646     return ConstantPoolArray::INT32;
   3647   } else if (RelocInfo::IsCodeTarget(rmode)) {
   3648     return ConstantPoolArray::CODE_PTR;
   3649   } else {
   3650     DCHECK(RelocInfo::IsGCRelocMode(rmode) && !RelocInfo::IsCodeTarget(rmode));
   3651     return ConstantPoolArray::HEAP_PTR;
   3652   }
   3653 }
   3654 
   3655 
   3656 ConstantPoolArray::LayoutSection ConstantPoolBuilder::AddEntry(
   3657     Assembler* assm, const RelocInfo& rinfo) {
   3658   RelocInfo::Mode rmode = rinfo.rmode();
   3659   DCHECK(rmode != RelocInfo::COMMENT &&
   3660          rmode != RelocInfo::POSITION &&
   3661          rmode != RelocInfo::STATEMENT_POSITION &&
   3662          rmode != RelocInfo::CONST_POOL);
   3663 
   3664   // Try to merge entries which won't be patched.
   3665   int merged_index = -1;
   3666   ConstantPoolArray::LayoutSection entry_section = current_section_;
   3667   if (RelocInfo::IsNone(rmode) ||
   3668       (!assm->serializer_enabled() && (rmode >= RelocInfo::CELL))) {
   3669     size_t i;
   3670     std::vector<ConstantPoolEntry>::const_iterator it;
   3671     for (it = entries_.begin(), i = 0; it != entries_.end(); it++, i++) {
   3672       if (RelocInfo::IsEqual(rinfo, it->rinfo_)) {
   3673         // Merge with found entry.
   3674         merged_index = i;
   3675         entry_section = entries_[i].section_;
   3676         break;
   3677       }
   3678     }
   3679   }
   3680   DCHECK(entry_section <= current_section_);
   3681   entries_.push_back(ConstantPoolEntry(rinfo, entry_section, merged_index));
   3682 
   3683   if (merged_index == -1) {
   3684     // Not merged, so update the appropriate count.
   3685     number_of_entries_[entry_section].increment(GetConstantPoolType(rmode));
   3686   }
   3687 
   3688   // Check if we still have room for another entry in the small section
   3689   // given Arm's ldr and vldr immediate offset range.
   3690   if (current_section_ == ConstantPoolArray::SMALL_SECTION &&
   3691       !(is_uint12(ConstantPoolArray::SizeFor(*small_entries())) &&
   3692         is_uint10(ConstantPoolArray::MaxInt64Offset(
   3693             small_entries()->count_of(ConstantPoolArray::INT64))))) {
   3694     current_section_ = ConstantPoolArray::EXTENDED_SECTION;
   3695   }
   3696   return entry_section;
   3697 }
   3698 
   3699 
   3700 void ConstantPoolBuilder::Relocate(int pc_delta) {
   3701   for (std::vector<ConstantPoolEntry>::iterator entry = entries_.begin();
   3702        entry != entries_.end(); entry++) {
   3703     DCHECK(entry->rinfo_.rmode() != RelocInfo::JS_RETURN);
   3704     entry->rinfo_.set_pc(entry->rinfo_.pc() + pc_delta);
   3705   }
   3706 }
   3707 
   3708 
   3709 Handle<ConstantPoolArray> ConstantPoolBuilder::New(Isolate* isolate) {
   3710   if (IsEmpty()) {
   3711     return isolate->factory()->empty_constant_pool_array();
   3712   } else if (extended_entries()->is_empty()) {
   3713     return isolate->factory()->NewConstantPoolArray(*small_entries());
   3714   } else {
   3715     DCHECK(current_section_ == ConstantPoolArray::EXTENDED_SECTION);
   3716     return isolate->factory()->NewExtendedConstantPoolArray(
   3717         *small_entries(), *extended_entries());
   3718   }
   3719 }
   3720 
   3721 
   3722 void ConstantPoolBuilder::Populate(Assembler* assm,
   3723                                    ConstantPoolArray* constant_pool) {
   3724   DCHECK_EQ(extended_entries()->is_empty(),
   3725             !constant_pool->is_extended_layout());
   3726   DCHECK(small_entries()->equals(ConstantPoolArray::NumberOfEntries(
   3727       constant_pool, ConstantPoolArray::SMALL_SECTION)));
   3728   if (constant_pool->is_extended_layout()) {
   3729     DCHECK(extended_entries()->equals(ConstantPoolArray::NumberOfEntries(
   3730         constant_pool, ConstantPoolArray::EXTENDED_SECTION)));
   3731   }
   3732 
   3733   // Set up initial offsets.
   3734   int offsets[ConstantPoolArray::NUMBER_OF_LAYOUT_SECTIONS]
   3735              [ConstantPoolArray::NUMBER_OF_TYPES];
   3736   for (int section = 0; section <= constant_pool->final_section(); section++) {
   3737     int section_start = (section == ConstantPoolArray::EXTENDED_SECTION)
   3738                             ? small_entries()->total_count()
   3739                             : 0;
   3740     for (int i = 0; i < ConstantPoolArray::NUMBER_OF_TYPES; i++) {
   3741       ConstantPoolArray::Type type = static_cast<ConstantPoolArray::Type>(i);
   3742       if (number_of_entries_[section].count_of(type) != 0) {
   3743         offsets[section][type] = constant_pool->OffsetOfElementAt(
   3744             number_of_entries_[section].base_of(type) + section_start);
   3745       }
   3746     }
   3747   }
   3748 
   3749   for (std::vector<ConstantPoolEntry>::iterator entry = entries_.begin();
   3750        entry != entries_.end(); entry++) {
   3751     RelocInfo rinfo = entry->rinfo_;
   3752     RelocInfo::Mode rmode = entry->rinfo_.rmode();
   3753     ConstantPoolArray::Type type = GetConstantPoolType(rmode);
   3754 
   3755     // Update constant pool if necessary and get the entry's offset.
   3756     int offset;
   3757     if (entry->merged_index_ == -1) {
   3758       offset = offsets[entry->section_][type];
   3759       offsets[entry->section_][type] += ConstantPoolArray::entry_size(type);
   3760       if (type == ConstantPoolArray::INT64) {
   3761         constant_pool->set_at_offset(offset, rinfo.data64());
   3762       } else if (type == ConstantPoolArray::INT32) {
   3763         constant_pool->set_at_offset(offset,
   3764                                      static_cast<int32_t>(rinfo.data()));
   3765       } else if (type == ConstantPoolArray::CODE_PTR) {
   3766         constant_pool->set_at_offset(offset,
   3767                                      reinterpret_cast<Address>(rinfo.data()));
   3768       } else {
   3769         DCHECK(type == ConstantPoolArray::HEAP_PTR);
   3770         constant_pool->set_at_offset(offset,
   3771                                      reinterpret_cast<Object*>(rinfo.data()));
   3772       }
   3773       offset -= kHeapObjectTag;
   3774       entry->merged_index_ = offset;  // Stash offset for merged entries.
   3775     } else {
   3776       DCHECK(entry->merged_index_ < (entry - entries_.begin()));
   3777       offset = entries_[entry->merged_index_].merged_index_;
   3778     }
   3779 
   3780     // Patch vldr/ldr instruction with correct offset.
   3781     Instr instr = assm->instr_at(rinfo.pc());
   3782     if (entry->section_ == ConstantPoolArray::EXTENDED_SECTION) {
   3783       if (CpuFeatures::IsSupported(ARMv7)) {
   3784         // Instructions to patch must be 'movw rd, [#0]' and 'movt rd, [#0].
   3785         Instr next_instr = assm->instr_at(rinfo.pc() + Assembler::kInstrSize);
   3786         DCHECK((Assembler::IsMovW(instr) &&
   3787                 Instruction::ImmedMovwMovtValue(instr) == 0));
   3788         DCHECK((Assembler::IsMovT(next_instr) &&
   3789                 Instruction::ImmedMovwMovtValue(next_instr) == 0));
   3790         assm->instr_at_put(
   3791             rinfo.pc(), Assembler::PatchMovwImmediate(instr, offset & 0xffff));
   3792         assm->instr_at_put(
   3793             rinfo.pc() + Assembler::kInstrSize,
   3794             Assembler::PatchMovwImmediate(next_instr, offset >> 16));
   3795       } else {
   3796         // Instructions to patch must be 'mov rd, [#0]' and 'orr rd, rd, [#0].
   3797         Instr instr_2 = assm->instr_at(rinfo.pc() + Assembler::kInstrSize);
   3798         Instr instr_3 = assm->instr_at(rinfo.pc() + 2 * Assembler::kInstrSize);
   3799         Instr instr_4 = assm->instr_at(rinfo.pc() + 3 * Assembler::kInstrSize);
   3800         DCHECK((Assembler::IsMovImmed(instr) &&
   3801                 Instruction::Immed8Value(instr) == 0));
   3802         DCHECK((Assembler::IsOrrImmed(instr_2) &&
   3803                 Instruction::Immed8Value(instr_2) == 0) &&
   3804                Assembler::GetRn(instr_2).is(Assembler::GetRd(instr_2)));
   3805         DCHECK((Assembler::IsOrrImmed(instr_3) &&
   3806                 Instruction::Immed8Value(instr_3) == 0) &&
   3807                Assembler::GetRn(instr_3).is(Assembler::GetRd(instr_3)));
   3808         DCHECK((Assembler::IsOrrImmed(instr_4) &&
   3809                 Instruction::Immed8Value(instr_4) == 0) &&
   3810                Assembler::GetRn(instr_4).is(Assembler::GetRd(instr_4)));
   3811         assm->instr_at_put(
   3812             rinfo.pc(), Assembler::PatchShiftImm(instr, (offset & kImm8Mask)));
   3813         assm->instr_at_put(
   3814             rinfo.pc() + Assembler::kInstrSize,
   3815             Assembler::PatchShiftImm(instr_2, (offset & (kImm8Mask << 8))));
   3816         assm->instr_at_put(
   3817             rinfo.pc() + 2 * Assembler::kInstrSize,
   3818             Assembler::PatchShiftImm(instr_3, (offset & (kImm8Mask << 16))));
   3819         assm->instr_at_put(
   3820             rinfo.pc() + 3 * Assembler::kInstrSize,
   3821             Assembler::PatchShiftImm(instr_4, (offset & (kImm8Mask << 24))));
   3822       }
   3823     } else if (type == ConstantPoolArray::INT64) {
   3824       // Instruction to patch must be 'vldr rd, [pp, #0]'.
   3825       DCHECK((Assembler::IsVldrDPpImmediateOffset(instr) &&
   3826               Assembler::GetVldrDRegisterImmediateOffset(instr) == 0));
   3827       DCHECK(is_uint10(offset));
   3828       assm->instr_at_put(rinfo.pc(), Assembler::SetVldrDRegisterImmediateOffset(
   3829                                          instr, offset));
   3830     } else {
   3831       // Instruction to patch must be 'ldr rd, [pp, #0]'.
   3832       DCHECK((Assembler::IsLdrPpImmediateOffset(instr) &&
   3833               Assembler::GetLdrRegisterImmediateOffset(instr) == 0));
   3834       DCHECK(is_uint12(offset));
   3835       assm->instr_at_put(
   3836           rinfo.pc(), Assembler::SetLdrRegisterImmediateOffset(instr, offset));
   3837     }
   3838   }
   3839 }
   3840 
   3841 
   3842 } }  // namespace v8::internal
   3843 
   3844 #endif  // V8_TARGET_ARCH_ARM
   3845