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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ART_COMPILER_UTILS_MIPS_ASSEMBLER_MIPS_H_
     18 #define ART_COMPILER_UTILS_MIPS_ASSEMBLER_MIPS_H_
     19 
     20 #include <deque>
     21 #include <utility>
     22 #include <vector>
     23 
     24 #include "arch/mips/instruction_set_features_mips.h"
     25 #include "base/arena_containers.h"
     26 #include "base/enums.h"
     27 #include "base/globals.h"
     28 #include "base/macros.h"
     29 #include "base/stl_util_identity.h"
     30 #include "constants_mips.h"
     31 #include "heap_poisoning.h"
     32 #include "managed_register_mips.h"
     33 #include "offsets.h"
     34 #include "utils/assembler.h"
     35 #include "utils/jni_macro_assembler.h"
     36 #include "utils/label.h"
     37 
     38 namespace art {
     39 namespace mips {
     40 
     41 static constexpr size_t kMipsHalfwordSize = 2;
     42 static constexpr size_t kMipsWordSize = 4;
     43 static constexpr size_t kMipsDoublewordSize = 8;
     44 
     45 enum LoadOperandType {
     46   kLoadSignedByte,
     47   kLoadUnsignedByte,
     48   kLoadSignedHalfword,
     49   kLoadUnsignedHalfword,
     50   kLoadWord,
     51   kLoadDoubleword,
     52   kLoadQuadword
     53 };
     54 
     55 enum StoreOperandType {
     56   kStoreByte,
     57   kStoreHalfword,
     58   kStoreWord,
     59   kStoreDoubleword,
     60   kStoreQuadword
     61 };
     62 
     63 // Used to test the values returned by ClassS/ClassD.
     64 enum FPClassMaskType {
     65   kSignalingNaN      = 0x001,
     66   kQuietNaN          = 0x002,
     67   kNegativeInfinity  = 0x004,
     68   kNegativeNormal    = 0x008,
     69   kNegativeSubnormal = 0x010,
     70   kNegativeZero      = 0x020,
     71   kPositiveInfinity  = 0x040,
     72   kPositiveNormal    = 0x080,
     73   kPositiveSubnormal = 0x100,
     74   kPositiveZero      = 0x200,
     75 };
     76 
     77 // Instruction description in terms of input and output registers.
     78 // Used for instruction reordering.
     79 struct InOutRegMasks {
     80   InOutRegMasks()
     81       : gpr_outs_(0), gpr_ins_(0), fpr_outs_(0), fpr_ins_(0), cc_outs_(0), cc_ins_(0) {}
     82 
     83   inline InOutRegMasks& GprOuts(Register reg) {
     84     gpr_outs_ |= (1u << reg);
     85     gpr_outs_ &= ~1u;  // Ignore register ZERO.
     86     return *this;
     87   }
     88   template<typename T, typename... Ts>
     89   inline InOutRegMasks& GprOuts(T one, Ts... more) { GprOuts(one); GprOuts(more...); return *this; }
     90 
     91   inline InOutRegMasks& GprIns(Register reg) {
     92     gpr_ins_ |= (1u << reg);
     93     gpr_ins_ &= ~1u;  // Ignore register ZERO.
     94     return *this;
     95   }
     96   template<typename T, typename... Ts>
     97   inline InOutRegMasks& GprIns(T one, Ts... more) { GprIns(one); GprIns(more...); return *this; }
     98 
     99   inline InOutRegMasks& GprInOuts(Register reg) { GprIns(reg); GprOuts(reg); return *this; }
    100   template<typename T, typename... Ts>
    101   inline InOutRegMasks& GprInOuts(T one, Ts... more) {
    102     GprInOuts(one);
    103     GprInOuts(more...);
    104     return *this;
    105   }
    106 
    107   inline InOutRegMasks& FprOuts(FRegister reg) { fpr_outs_ |= (1u << reg); return *this; }
    108   inline InOutRegMasks& FprOuts(VectorRegister reg) { return FprOuts(static_cast<FRegister>(reg)); }
    109   template<typename T, typename... Ts>
    110   inline InOutRegMasks& FprOuts(T one, Ts... more) { FprOuts(one); FprOuts(more...); return *this; }
    111 
    112   inline InOutRegMasks& FprIns(FRegister reg) { fpr_ins_ |= (1u << reg); return *this; }
    113   inline InOutRegMasks& FprIns(VectorRegister reg) { return FprIns(static_cast<FRegister>(reg)); }
    114   template<typename T, typename... Ts>
    115   inline InOutRegMasks& FprIns(T one, Ts... more) { FprIns(one); FprIns(more...); return *this; }
    116 
    117   inline InOutRegMasks& FprInOuts(FRegister reg) { FprIns(reg); FprOuts(reg); return *this; }
    118   inline InOutRegMasks& FprInOuts(VectorRegister reg) {
    119     return FprInOuts(static_cast<FRegister>(reg));
    120   }
    121   template<typename T, typename... Ts>
    122   inline InOutRegMasks& FprInOuts(T one, Ts... more) {
    123     FprInOuts(one);
    124     FprInOuts(more...);
    125     return *this;
    126   }
    127 
    128   inline InOutRegMasks& CcOuts(int cc) { cc_outs_ |= (1u << cc); return *this; }
    129   template<typename T, typename... Ts>
    130   inline InOutRegMasks& CcOuts(T one, Ts... more) { CcOuts(one); CcOuts(more...); return *this; }
    131 
    132   inline InOutRegMasks& CcIns(int cc) { cc_ins_ |= (1u << cc); return *this; }
    133   template<typename T, typename... Ts>
    134   inline InOutRegMasks& CcIns(T one, Ts... more) { CcIns(one); CcIns(more...); return *this; }
    135 
    136   // Mask of output GPRs for the instruction.
    137   uint32_t gpr_outs_;
    138   // Mask of input GPRs for the instruction.
    139   uint32_t gpr_ins_;
    140   // Mask of output FPRs for the instruction.
    141   uint32_t fpr_outs_;
    142   // Mask of input FPRs for the instruction.
    143   uint32_t fpr_ins_;
    144   // Mask of output FPU condition code flags for the instruction.
    145   uint32_t cc_outs_;
    146   // Mask of input FPU condition code flags for the instruction.
    147   uint32_t cc_ins_;
    148 
    149   // TODO: add LO and HI.
    150 };
    151 
    152 class MipsLabel : public Label {
    153  public:
    154   MipsLabel() : prev_branch_id_plus_one_(0) {}
    155 
    156   MipsLabel(MipsLabel&& src)
    157       : Label(std::move(src)), prev_branch_id_plus_one_(src.prev_branch_id_plus_one_) {}
    158 
    159   void AdjustBoundPosition(int delta) {
    160     CHECK(IsBound());
    161     // Bound label's position is negative, hence decrementing it.
    162     position_ -= delta;
    163   }
    164 
    165  private:
    166   uint32_t prev_branch_id_plus_one_;  // To get distance from preceding branch, if any.
    167 
    168   friend class MipsAssembler;
    169   DISALLOW_COPY_AND_ASSIGN(MipsLabel);
    170 };
    171 
    172 // Assembler literal is a value embedded in code, retrieved using a PC-relative load.
    173 class Literal {
    174  public:
    175   static constexpr size_t kMaxSize = 8;
    176 
    177   Literal(uint32_t size, const uint8_t* data)
    178       : label_(), size_(size) {
    179     DCHECK_LE(size, Literal::kMaxSize);
    180     memcpy(data_, data, size);
    181   }
    182 
    183   template <typename T>
    184   T GetValue() const {
    185     DCHECK_EQ(size_, sizeof(T));
    186     T value;
    187     memcpy(&value, data_, sizeof(T));
    188     return value;
    189   }
    190 
    191   uint32_t GetSize() const {
    192     return size_;
    193   }
    194 
    195   const uint8_t* GetData() const {
    196     return data_;
    197   }
    198 
    199   MipsLabel* GetLabel() {
    200     return &label_;
    201   }
    202 
    203   const MipsLabel* GetLabel() const {
    204     return &label_;
    205   }
    206 
    207  private:
    208   MipsLabel label_;
    209   const uint32_t size_;
    210   uint8_t data_[kMaxSize];
    211 
    212   DISALLOW_COPY_AND_ASSIGN(Literal);
    213 };
    214 
    215 // Jump table: table of labels emitted after the literals. Similar to literals.
    216 class JumpTable {
    217  public:
    218   explicit JumpTable(std::vector<MipsLabel*>&& labels)
    219       : label_(), labels_(std::move(labels)) {
    220   }
    221 
    222   uint32_t GetSize() const {
    223     return static_cast<uint32_t>(labels_.size()) * sizeof(uint32_t);
    224   }
    225 
    226   const std::vector<MipsLabel*>& GetData() const {
    227     return labels_;
    228   }
    229 
    230   MipsLabel* GetLabel() {
    231     return &label_;
    232   }
    233 
    234   const MipsLabel* GetLabel() const {
    235     return &label_;
    236   }
    237 
    238  private:
    239   MipsLabel label_;
    240   std::vector<MipsLabel*> labels_;
    241 
    242   DISALLOW_COPY_AND_ASSIGN(JumpTable);
    243 };
    244 
    245 // Slowpath entered when Thread::Current()->_exception is non-null.
    246 class MipsExceptionSlowPath {
    247  public:
    248   explicit MipsExceptionSlowPath(MipsManagedRegister scratch, size_t stack_adjust)
    249       : scratch_(scratch), stack_adjust_(stack_adjust) {}
    250 
    251   MipsExceptionSlowPath(MipsExceptionSlowPath&& src)
    252       : scratch_(src.scratch_),
    253         stack_adjust_(src.stack_adjust_),
    254         exception_entry_(std::move(src.exception_entry_)) {}
    255 
    256  private:
    257   MipsLabel* Entry() { return &exception_entry_; }
    258   const MipsManagedRegister scratch_;
    259   const size_t stack_adjust_;
    260   MipsLabel exception_entry_;
    261 
    262   friend class MipsAssembler;
    263   DISALLOW_COPY_AND_ASSIGN(MipsExceptionSlowPath);
    264 };
    265 
    266 class MipsAssembler final : public Assembler, public JNIMacroAssembler<PointerSize::k32> {
    267  public:
    268   using JNIBase = JNIMacroAssembler<PointerSize::k32>;
    269 
    270   explicit MipsAssembler(ArenaAllocator* allocator,
    271                          const MipsInstructionSetFeatures* instruction_set_features = nullptr)
    272       : Assembler(allocator),
    273         overwriting_(false),
    274         overwrite_location_(0),
    275         reordering_(true),
    276         ds_fsm_state_(kExpectingLabel),
    277         ds_fsm_target_pc_(0),
    278         literals_(allocator->Adapter(kArenaAllocAssembler)),
    279         jump_tables_(allocator->Adapter(kArenaAllocAssembler)),
    280         last_position_adjustment_(0),
    281         last_old_position_(0),
    282         last_branch_id_(0),
    283         has_msa_(instruction_set_features != nullptr ? instruction_set_features->HasMsa() : false),
    284         isa_features_(instruction_set_features) {
    285     cfi().DelayEmittingAdvancePCs();
    286   }
    287 
    288   size_t CodeSize() const override { return Assembler::CodeSize(); }
    289   size_t CodePosition() override;
    290   DebugFrameOpCodeWriterForAssembler& cfi() override { return Assembler::cfi(); }
    291 
    292   virtual ~MipsAssembler() {
    293     for (auto& branch : branches_) {
    294       CHECK(branch.IsResolved());
    295     }
    296   }
    297 
    298   // Emit Machine Instructions.
    299   void Addu(Register rd, Register rs, Register rt);
    300   void Addiu(Register rt, Register rs, uint16_t imm16, MipsLabel* patcher_label);
    301   void Addiu(Register rt, Register rs, uint16_t imm16);
    302   void Subu(Register rd, Register rs, Register rt);
    303 
    304   void MultR2(Register rs, Register rt);  // R2
    305   void MultuR2(Register rs, Register rt);  // R2
    306   void DivR2(Register rs, Register rt);  // R2
    307   void DivuR2(Register rs, Register rt);  // R2
    308   void MulR2(Register rd, Register rs, Register rt);  // R2
    309   void DivR2(Register rd, Register rs, Register rt);  // R2
    310   void ModR2(Register rd, Register rs, Register rt);  // R2
    311   void DivuR2(Register rd, Register rs, Register rt);  // R2
    312   void ModuR2(Register rd, Register rs, Register rt);  // R2
    313   void MulR6(Register rd, Register rs, Register rt);  // R6
    314   void MuhR6(Register rd, Register rs, Register rt);  // R6
    315   void MuhuR6(Register rd, Register rs, Register rt);  // R6
    316   void DivR6(Register rd, Register rs, Register rt);  // R6
    317   void ModR6(Register rd, Register rs, Register rt);  // R6
    318   void DivuR6(Register rd, Register rs, Register rt);  // R6
    319   void ModuR6(Register rd, Register rs, Register rt);  // R6
    320 
    321   void And(Register rd, Register rs, Register rt);
    322   void Andi(Register rt, Register rs, uint16_t imm16);
    323   void Or(Register rd, Register rs, Register rt);
    324   void Ori(Register rt, Register rs, uint16_t imm16);
    325   void Xor(Register rd, Register rs, Register rt);
    326   void Xori(Register rt, Register rs, uint16_t imm16);
    327   void Nor(Register rd, Register rs, Register rt);
    328 
    329   void Movz(Register rd, Register rs, Register rt);  // R2
    330   void Movn(Register rd, Register rs, Register rt);  // R2
    331   void Seleqz(Register rd, Register rs, Register rt);  // R6
    332   void Selnez(Register rd, Register rs, Register rt);  // R6
    333   void ClzR6(Register rd, Register rs);
    334   void ClzR2(Register rd, Register rs);
    335   void CloR6(Register rd, Register rs);
    336   void CloR2(Register rd, Register rs);
    337 
    338   void Seb(Register rd, Register rt);  // R2+
    339   void Seh(Register rd, Register rt);  // R2+
    340   void Wsbh(Register rd, Register rt);  // R2+
    341   void Bitswap(Register rd, Register rt);  // R6
    342 
    343   void Sll(Register rd, Register rt, int shamt);
    344   void Srl(Register rd, Register rt, int shamt);
    345   void Rotr(Register rd, Register rt, int shamt);  // R2+
    346   void Sra(Register rd, Register rt, int shamt);
    347   void Sllv(Register rd, Register rt, Register rs);
    348   void Srlv(Register rd, Register rt, Register rs);
    349   void Rotrv(Register rd, Register rt, Register rs);  // R2+
    350   void Srav(Register rd, Register rt, Register rs);
    351   void Ext(Register rd, Register rt, int pos, int size);  // R2+
    352   void Ins(Register rd, Register rt, int pos, int size);  // R2+
    353   void Lsa(Register rd, Register rs, Register rt, int saPlusOne);  // R6
    354   void ShiftAndAdd(Register dst, Register src_idx, Register src_base, int shamt, Register tmp = AT);
    355 
    356   void Lb(Register rt, Register rs, uint16_t imm16);
    357   void Lh(Register rt, Register rs, uint16_t imm16);
    358   void Lw(Register rt, Register rs, uint16_t imm16, MipsLabel* patcher_label);
    359   void Lw(Register rt, Register rs, uint16_t imm16);
    360   void Lwl(Register rt, Register rs, uint16_t imm16);
    361   void Lwr(Register rt, Register rs, uint16_t imm16);
    362   void Lbu(Register rt, Register rs, uint16_t imm16);
    363   void Lhu(Register rt, Register rs, uint16_t imm16);
    364   void Lwpc(Register rs, uint32_t imm19);  // R6
    365   void Lui(Register rt, uint16_t imm16);
    366   void Aui(Register rt, Register rs, uint16_t imm16);  // R6
    367   void AddUpper(Register rt, Register rs, uint16_t imm16, Register tmp = AT);
    368   void Sync(uint32_t stype);
    369   void Mfhi(Register rd);  // R2
    370   void Mflo(Register rd);  // R2
    371 
    372   void Sb(Register rt, Register rs, uint16_t imm16);
    373   void Sh(Register rt, Register rs, uint16_t imm16);
    374   void Sw(Register rt, Register rs, uint16_t imm16, MipsLabel* patcher_label);
    375   void Sw(Register rt, Register rs, uint16_t imm16);
    376   void Swl(Register rt, Register rs, uint16_t imm16);
    377   void Swr(Register rt, Register rs, uint16_t imm16);
    378 
    379   void LlR2(Register rt, Register base, int16_t imm16 = 0);
    380   void ScR2(Register rt, Register base, int16_t imm16 = 0);
    381   void LlR6(Register rt, Register base, int16_t imm9 = 0);
    382   void ScR6(Register rt, Register base, int16_t imm9 = 0);
    383 
    384   void Slt(Register rd, Register rs, Register rt);
    385   void Sltu(Register rd, Register rs, Register rt);
    386   void Slti(Register rt, Register rs, uint16_t imm16);
    387   void Sltiu(Register rt, Register rs, uint16_t imm16);
    388 
    389   // Branches and jumps to immediate offsets/addresses do not take care of their
    390   // delay/forbidden slots and generally should not be used directly. This applies
    391   // to the following R2 and R6 branch/jump instructions with imm16, imm21, addr26
    392   // offsets/addresses.
    393   // Use branches/jumps to labels instead.
    394   void B(uint16_t imm16);
    395   void Bal(uint16_t imm16);
    396   void Beq(Register rs, Register rt, uint16_t imm16);
    397   void Bne(Register rs, Register rt, uint16_t imm16);
    398   void Beqz(Register rt, uint16_t imm16);
    399   void Bnez(Register rt, uint16_t imm16);
    400   void Bltz(Register rt, uint16_t imm16);
    401   void Bgez(Register rt, uint16_t imm16);
    402   void Blez(Register rt, uint16_t imm16);
    403   void Bgtz(Register rt, uint16_t imm16);
    404   void Bc1f(uint16_t imm16);  // R2
    405   void Bc1f(int cc, uint16_t imm16);  // R2
    406   void Bc1t(uint16_t imm16);  // R2
    407   void Bc1t(int cc, uint16_t imm16);  // R2
    408   void J(uint32_t addr26);
    409   void Jal(uint32_t addr26);
    410   // Jalr() and Jr() fill their delay slots when reordering is enabled.
    411   // When reordering is disabled, the delay slots must be filled manually.
    412   // You may use NopIfNoReordering() to fill them when reordering is disabled.
    413   void Jalr(Register rd, Register rs);
    414   void Jalr(Register rs);
    415   void Jr(Register rs);
    416   // Nal() does not fill its delay slot. It must be filled manually.
    417   void Nal();
    418   void Auipc(Register rs, uint16_t imm16);  // R6
    419   void Addiupc(Register rs, uint32_t imm19);  // R6
    420   void Bc(uint32_t imm26);  // R6
    421   void Balc(uint32_t imm26);  // R6
    422   void Jic(Register rt, uint16_t imm16);  // R6
    423   void Jialc(Register rt, uint16_t imm16);  // R6
    424   void Bltc(Register rs, Register rt, uint16_t imm16);  // R6
    425   void Bltzc(Register rt, uint16_t imm16);  // R6
    426   void Bgtzc(Register rt, uint16_t imm16);  // R6
    427   void Bgec(Register rs, Register rt, uint16_t imm16);  // R6
    428   void Bgezc(Register rt, uint16_t imm16);  // R6
    429   void Blezc(Register rt, uint16_t imm16);  // R6
    430   void Bltuc(Register rs, Register rt, uint16_t imm16);  // R6
    431   void Bgeuc(Register rs, Register rt, uint16_t imm16);  // R6
    432   void Beqc(Register rs, Register rt, uint16_t imm16);  // R6
    433   void Bnec(Register rs, Register rt, uint16_t imm16);  // R6
    434   void Beqzc(Register rs, uint32_t imm21);  // R6
    435   void Bnezc(Register rs, uint32_t imm21);  // R6
    436   void Bc1eqz(FRegister ft, uint16_t imm16);  // R6
    437   void Bc1nez(FRegister ft, uint16_t imm16);  // R6
    438 
    439   void AddS(FRegister fd, FRegister fs, FRegister ft);
    440   void SubS(FRegister fd, FRegister fs, FRegister ft);
    441   void MulS(FRegister fd, FRegister fs, FRegister ft);
    442   void DivS(FRegister fd, FRegister fs, FRegister ft);
    443   void AddD(FRegister fd, FRegister fs, FRegister ft);
    444   void SubD(FRegister fd, FRegister fs, FRegister ft);
    445   void MulD(FRegister fd, FRegister fs, FRegister ft);
    446   void DivD(FRegister fd, FRegister fs, FRegister ft);
    447   void SqrtS(FRegister fd, FRegister fs);
    448   void SqrtD(FRegister fd, FRegister fs);
    449   void AbsS(FRegister fd, FRegister fs);
    450   void AbsD(FRegister fd, FRegister fs);
    451   void MovS(FRegister fd, FRegister fs);
    452   void MovD(FRegister fd, FRegister fs);
    453   void NegS(FRegister fd, FRegister fs);
    454   void NegD(FRegister fd, FRegister fs);
    455 
    456   void CunS(FRegister fs, FRegister ft);  // R2
    457   void CunS(int cc, FRegister fs, FRegister ft);  // R2
    458   void CeqS(FRegister fs, FRegister ft);  // R2
    459   void CeqS(int cc, FRegister fs, FRegister ft);  // R2
    460   void CueqS(FRegister fs, FRegister ft);  // R2
    461   void CueqS(int cc, FRegister fs, FRegister ft);  // R2
    462   void ColtS(FRegister fs, FRegister ft);  // R2
    463   void ColtS(int cc, FRegister fs, FRegister ft);  // R2
    464   void CultS(FRegister fs, FRegister ft);  // R2
    465   void CultS(int cc, FRegister fs, FRegister ft);  // R2
    466   void ColeS(FRegister fs, FRegister ft);  // R2
    467   void ColeS(int cc, FRegister fs, FRegister ft);  // R2
    468   void CuleS(FRegister fs, FRegister ft);  // R2
    469   void CuleS(int cc, FRegister fs, FRegister ft);  // R2
    470   void CunD(FRegister fs, FRegister ft);  // R2
    471   void CunD(int cc, FRegister fs, FRegister ft);  // R2
    472   void CeqD(FRegister fs, FRegister ft);  // R2
    473   void CeqD(int cc, FRegister fs, FRegister ft);  // R2
    474   void CueqD(FRegister fs, FRegister ft);  // R2
    475   void CueqD(int cc, FRegister fs, FRegister ft);  // R2
    476   void ColtD(FRegister fs, FRegister ft);  // R2
    477   void ColtD(int cc, FRegister fs, FRegister ft);  // R2
    478   void CultD(FRegister fs, FRegister ft);  // R2
    479   void CultD(int cc, FRegister fs, FRegister ft);  // R2
    480   void ColeD(FRegister fs, FRegister ft);  // R2
    481   void ColeD(int cc, FRegister fs, FRegister ft);  // R2
    482   void CuleD(FRegister fs, FRegister ft);  // R2
    483   void CuleD(int cc, FRegister fs, FRegister ft);  // R2
    484   void CmpUnS(FRegister fd, FRegister fs, FRegister ft);  // R6
    485   void CmpEqS(FRegister fd, FRegister fs, FRegister ft);  // R6
    486   void CmpUeqS(FRegister fd, FRegister fs, FRegister ft);  // R6
    487   void CmpLtS(FRegister fd, FRegister fs, FRegister ft);  // R6
    488   void CmpUltS(FRegister fd, FRegister fs, FRegister ft);  // R6
    489   void CmpLeS(FRegister fd, FRegister fs, FRegister ft);  // R6
    490   void CmpUleS(FRegister fd, FRegister fs, FRegister ft);  // R6
    491   void CmpOrS(FRegister fd, FRegister fs, FRegister ft);  // R6
    492   void CmpUneS(FRegister fd, FRegister fs, FRegister ft);  // R6
    493   void CmpNeS(FRegister fd, FRegister fs, FRegister ft);  // R6
    494   void CmpUnD(FRegister fd, FRegister fs, FRegister ft);  // R6
    495   void CmpEqD(FRegister fd, FRegister fs, FRegister ft);  // R6
    496   void CmpUeqD(FRegister fd, FRegister fs, FRegister ft);  // R6
    497   void CmpLtD(FRegister fd, FRegister fs, FRegister ft);  // R6
    498   void CmpUltD(FRegister fd, FRegister fs, FRegister ft);  // R6
    499   void CmpLeD(FRegister fd, FRegister fs, FRegister ft);  // R6
    500   void CmpUleD(FRegister fd, FRegister fs, FRegister ft);  // R6
    501   void CmpOrD(FRegister fd, FRegister fs, FRegister ft);  // R6
    502   void CmpUneD(FRegister fd, FRegister fs, FRegister ft);  // R6
    503   void CmpNeD(FRegister fd, FRegister fs, FRegister ft);  // R6
    504   void Movf(Register rd, Register rs, int cc = 0);  // R2
    505   void Movt(Register rd, Register rs, int cc = 0);  // R2
    506   void MovfS(FRegister fd, FRegister fs, int cc = 0);  // R2
    507   void MovfD(FRegister fd, FRegister fs, int cc = 0);  // R2
    508   void MovtS(FRegister fd, FRegister fs, int cc = 0);  // R2
    509   void MovtD(FRegister fd, FRegister fs, int cc = 0);  // R2
    510   void MovzS(FRegister fd, FRegister fs, Register rt);  // R2
    511   void MovzD(FRegister fd, FRegister fs, Register rt);  // R2
    512   void MovnS(FRegister fd, FRegister fs, Register rt);  // R2
    513   void MovnD(FRegister fd, FRegister fs, Register rt);  // R2
    514   void SelS(FRegister fd, FRegister fs, FRegister ft);  // R6
    515   void SelD(FRegister fd, FRegister fs, FRegister ft);  // R6
    516   void SeleqzS(FRegister fd, FRegister fs, FRegister ft);  // R6
    517   void SeleqzD(FRegister fd, FRegister fs, FRegister ft);  // R6
    518   void SelnezS(FRegister fd, FRegister fs, FRegister ft);  // R6
    519   void SelnezD(FRegister fd, FRegister fs, FRegister ft);  // R6
    520   void ClassS(FRegister fd, FRegister fs);  // R6
    521   void ClassD(FRegister fd, FRegister fs);  // R6
    522   void MinS(FRegister fd, FRegister fs, FRegister ft);  // R6
    523   void MinD(FRegister fd, FRegister fs, FRegister ft);  // R6
    524   void MaxS(FRegister fd, FRegister fs, FRegister ft);  // R6
    525   void MaxD(FRegister fd, FRegister fs, FRegister ft);  // R6
    526 
    527   void TruncLS(FRegister fd, FRegister fs);  // R2+, FR=1
    528   void TruncLD(FRegister fd, FRegister fs);  // R2+, FR=1
    529   void TruncWS(FRegister fd, FRegister fs);
    530   void TruncWD(FRegister fd, FRegister fs);
    531   void Cvtsw(FRegister fd, FRegister fs);
    532   void Cvtdw(FRegister fd, FRegister fs);
    533   void Cvtsd(FRegister fd, FRegister fs);
    534   void Cvtds(FRegister fd, FRegister fs);
    535   void Cvtsl(FRegister fd, FRegister fs);  // R2+, FR=1
    536   void Cvtdl(FRegister fd, FRegister fs);  // R2+, FR=1
    537   void FloorWS(FRegister fd, FRegister fs);
    538   void FloorWD(FRegister fd, FRegister fs);
    539 
    540   // Note, the 32 LSBs of a 64-bit value must be loaded into an FPR before the 32 MSBs
    541   // when loading the value as 32-bit halves. This applies to all 32-bit FPR loads:
    542   // Mtc1(), Mthc1(), MoveToFpuHigh(), Lwc1(). Even if you need two Mtc1()'s or two
    543   // Lwc1()'s to load a pair of 32-bit FPRs and these loads do not interfere with one
    544   // another (unlike Mtc1() and Mthc1() with 64-bit FPRs), maintain the order:
    545   // low then high.
    546   //
    547   // Also, prefer MoveFromFpuHigh()/MoveToFpuHigh() over Mfhc1()/Mthc1() and Mfc1()/Mtc1().
    548   // This will save you some if statements.
    549   FRegister GetFpuRegLow(FRegister reg);
    550   void Mfc1(Register rt, FRegister fs);
    551   void Mtc1(Register rt, FRegister fs);
    552   void Mfhc1(Register rt, FRegister fs);
    553   void Mthc1(Register rt, FRegister fs);
    554   void MoveFromFpuHigh(Register rt, FRegister fs);
    555   void MoveToFpuHigh(Register rt, FRegister fs);
    556   void Lwc1(FRegister ft, Register rs, uint16_t imm16);
    557   void Ldc1(FRegister ft, Register rs, uint16_t imm16);
    558   void Swc1(FRegister ft, Register rs, uint16_t imm16);
    559   void Sdc1(FRegister ft, Register rs, uint16_t imm16);
    560 
    561   void Break();
    562   void Nop();
    563   void NopIfNoReordering();
    564   void Move(Register rd, Register rs);
    565   void Clear(Register rd);
    566   void Not(Register rd, Register rs);
    567 
    568   // MSA instructions.
    569   void AndV(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    570   void OrV(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    571   void NorV(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    572   void XorV(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    573 
    574   void AddvB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    575   void AddvH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    576   void AddvW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    577   void AddvD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    578   void SubvB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    579   void SubvH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    580   void SubvW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    581   void SubvD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    582   void Asub_sB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    583   void Asub_sH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    584   void Asub_sW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    585   void Asub_sD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    586   void Asub_uB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    587   void Asub_uH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    588   void Asub_uW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    589   void Asub_uD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    590   void MulvB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    591   void MulvH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    592   void MulvW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    593   void MulvD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    594   void Div_sB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    595   void Div_sH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    596   void Div_sW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    597   void Div_sD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    598   void Div_uB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    599   void Div_uH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    600   void Div_uW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    601   void Div_uD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    602   void Mod_sB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    603   void Mod_sH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    604   void Mod_sW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    605   void Mod_sD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    606   void Mod_uB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    607   void Mod_uH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    608   void Mod_uW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    609   void Mod_uD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    610   void Add_aB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    611   void Add_aH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    612   void Add_aW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    613   void Add_aD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    614   void Ave_sB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    615   void Ave_sH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    616   void Ave_sW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    617   void Ave_sD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    618   void Ave_uB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    619   void Ave_uH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    620   void Ave_uW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    621   void Ave_uD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    622   void Aver_sB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    623   void Aver_sH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    624   void Aver_sW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    625   void Aver_sD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    626   void Aver_uB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    627   void Aver_uH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    628   void Aver_uW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    629   void Aver_uD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    630   void Max_sB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    631   void Max_sH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    632   void Max_sW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    633   void Max_sD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    634   void Max_uB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    635   void Max_uH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    636   void Max_uW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    637   void Max_uD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    638   void Min_sB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    639   void Min_sH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    640   void Min_sW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    641   void Min_sD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    642   void Min_uB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    643   void Min_uH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    644   void Min_uW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    645   void Min_uD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    646 
    647   void FaddW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    648   void FaddD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    649   void FsubW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    650   void FsubD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    651   void FmulW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    652   void FmulD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    653   void FdivW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    654   void FdivD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    655   void FmaxW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    656   void FmaxD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    657   void FminW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    658   void FminD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    659 
    660   void Ffint_sW(VectorRegister wd, VectorRegister ws);
    661   void Ffint_sD(VectorRegister wd, VectorRegister ws);
    662   void Ftint_sW(VectorRegister wd, VectorRegister ws);
    663   void Ftint_sD(VectorRegister wd, VectorRegister ws);
    664 
    665   void SllB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    666   void SllH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    667   void SllW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    668   void SllD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    669   void SraB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    670   void SraH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    671   void SraW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    672   void SraD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    673   void SrlB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    674   void SrlH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    675   void SrlW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    676   void SrlD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    677 
    678   // Immediate shift instructions, where shamtN denotes shift amount (must be between 0 and 2^N-1).
    679   void SlliB(VectorRegister wd, VectorRegister ws, int shamt3);
    680   void SlliH(VectorRegister wd, VectorRegister ws, int shamt4);
    681   void SlliW(VectorRegister wd, VectorRegister ws, int shamt5);
    682   void SlliD(VectorRegister wd, VectorRegister ws, int shamt6);
    683   void SraiB(VectorRegister wd, VectorRegister ws, int shamt3);
    684   void SraiH(VectorRegister wd, VectorRegister ws, int shamt4);
    685   void SraiW(VectorRegister wd, VectorRegister ws, int shamt5);
    686   void SraiD(VectorRegister wd, VectorRegister ws, int shamt6);
    687   void SrliB(VectorRegister wd, VectorRegister ws, int shamt3);
    688   void SrliH(VectorRegister wd, VectorRegister ws, int shamt4);
    689   void SrliW(VectorRegister wd, VectorRegister ws, int shamt5);
    690   void SrliD(VectorRegister wd, VectorRegister ws, int shamt6);
    691 
    692   void MoveV(VectorRegister wd, VectorRegister ws);
    693   void SplatiB(VectorRegister wd, VectorRegister ws, int n4);
    694   void SplatiH(VectorRegister wd, VectorRegister ws, int n3);
    695   void SplatiW(VectorRegister wd, VectorRegister ws, int n2);
    696   void SplatiD(VectorRegister wd, VectorRegister ws, int n1);
    697   void Copy_sB(Register rd, VectorRegister ws, int n4);
    698   void Copy_sH(Register rd, VectorRegister ws, int n3);
    699   void Copy_sW(Register rd, VectorRegister ws, int n2);
    700   void Copy_uB(Register rd, VectorRegister ws, int n4);
    701   void Copy_uH(Register rd, VectorRegister ws, int n3);
    702   void InsertB(VectorRegister wd, Register rs, int n4);
    703   void InsertH(VectorRegister wd, Register rs, int n3);
    704   void InsertW(VectorRegister wd, Register rs, int n2);
    705   void FillB(VectorRegister wd, Register rs);
    706   void FillH(VectorRegister wd, Register rs);
    707   void FillW(VectorRegister wd, Register rs);
    708 
    709   void LdiB(VectorRegister wd, int imm8);
    710   void LdiH(VectorRegister wd, int imm10);
    711   void LdiW(VectorRegister wd, int imm10);
    712   void LdiD(VectorRegister wd, int imm10);
    713   void LdB(VectorRegister wd, Register rs, int offset);
    714   void LdH(VectorRegister wd, Register rs, int offset);
    715   void LdW(VectorRegister wd, Register rs, int offset);
    716   void LdD(VectorRegister wd, Register rs, int offset);
    717   void StB(VectorRegister wd, Register rs, int offset);
    718   void StH(VectorRegister wd, Register rs, int offset);
    719   void StW(VectorRegister wd, Register rs, int offset);
    720   void StD(VectorRegister wd, Register rs, int offset);
    721 
    722   void IlvlB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    723   void IlvlH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    724   void IlvlW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    725   void IlvlD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    726   void IlvrB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    727   void IlvrH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    728   void IlvrW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    729   void IlvrD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    730   void IlvevB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    731   void IlvevH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    732   void IlvevW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    733   void IlvevD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    734   void IlvodB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    735   void IlvodH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    736   void IlvodW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    737   void IlvodD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    738 
    739   void MaddvB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    740   void MaddvH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    741   void MaddvW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    742   void MaddvD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    743   void MsubvB(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    744   void MsubvH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    745   void MsubvW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    746   void MsubvD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    747   void FmaddW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    748   void FmaddD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    749   void FmsubW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    750   void FmsubD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    751 
    752   void Hadd_sH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    753   void Hadd_sW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    754   void Hadd_sD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    755   void Hadd_uH(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    756   void Hadd_uW(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    757   void Hadd_uD(VectorRegister wd, VectorRegister ws, VectorRegister wt);
    758 
    759   void PcntB(VectorRegister wd, VectorRegister ws);
    760   void PcntH(VectorRegister wd, VectorRegister ws);
    761   void PcntW(VectorRegister wd, VectorRegister ws);
    762   void PcntD(VectorRegister wd, VectorRegister ws);
    763 
    764   // Helper for replicating floating point value in all destination elements.
    765   void ReplicateFPToVectorRegister(VectorRegister dst, FRegister src, bool is_double);
    766 
    767   // Higher level composite instructions.
    768   void LoadConst32(Register rd, int32_t value);
    769   void LoadConst64(Register reg_hi, Register reg_lo, int64_t value);
    770   void LoadDConst64(FRegister rd, int64_t value, Register temp);
    771   void LoadSConst32(FRegister r, int32_t value, Register temp);
    772   void Addiu32(Register rt, Register rs, int32_t value, Register rtmp = AT);
    773 
    774   void Bind(MipsLabel* label);
    775   // When `is_bare` is false, the branches will promote to long (if the range
    776   // of the individual branch instruction is insufficient) and the delay/
    777   // forbidden slots will be taken care of.
    778   // Use `is_bare = false` when the branch target may be out of reach of the
    779   // individual branch instruction. IOW, this is for general purpose use.
    780   //
    781   // When `is_bare` is true, just the branch instructions will be generated
    782   // leaving delay/forbidden slot filling up to the caller and the branches
    783   // won't promote to long if the range is insufficient (you'll get a
    784   // compilation error when the range is exceeded).
    785   // Use `is_bare = true` when the branch target is known to be within reach
    786   // of the individual branch instruction. This is intended for small local
    787   // optimizations around delay/forbidden slots.
    788   // Also prefer using `is_bare = true` if the code near the branch is to be
    789   // patched or analyzed at run time (e.g. introspection) to
    790   // - show the intent and
    791   // - fail during compilation rather than during patching/execution if the
    792   //   bare branch range is insufficent but the code size and layout are
    793   //   expected to remain unchanged
    794   //
    795   // R2 branches with delay slots that are also available on R6.
    796   // On R6 when `is_bare` is false these convert to equivalent R6 compact
    797   // branches (to reduce code size). On R2 or when `is_bare` is true they
    798   // remain R2 branches with delay slots.
    799   void B(MipsLabel* label, bool is_bare = false);
    800   void Bal(MipsLabel* label, bool is_bare = false);
    801   void Beq(Register rs, Register rt, MipsLabel* label, bool is_bare = false);
    802   void Bne(Register rs, Register rt, MipsLabel* label, bool is_bare = false);
    803   void Beqz(Register rt, MipsLabel* label, bool is_bare = false);
    804   void Bnez(Register rt, MipsLabel* label, bool is_bare = false);
    805   void Bltz(Register rt, MipsLabel* label, bool is_bare = false);
    806   void Bgez(Register rt, MipsLabel* label, bool is_bare = false);
    807   void Blez(Register rt, MipsLabel* label, bool is_bare = false);
    808   void Bgtz(Register rt, MipsLabel* label, bool is_bare = false);
    809   void Blt(Register rs, Register rt, MipsLabel* label, bool is_bare = false);
    810   void Bge(Register rs, Register rt, MipsLabel* label, bool is_bare = false);
    811   void Bltu(Register rs, Register rt, MipsLabel* label, bool is_bare = false);
    812   void Bgeu(Register rs, Register rt, MipsLabel* label, bool is_bare = false);
    813   // R2-only branches with delay slots.
    814   void Bc1f(MipsLabel* label, bool is_bare = false);  // R2
    815   void Bc1f(int cc, MipsLabel* label, bool is_bare = false);  // R2
    816   void Bc1t(MipsLabel* label, bool is_bare = false);  // R2
    817   void Bc1t(int cc, MipsLabel* label, bool is_bare = false);  // R2
    818   // R6-only compact branches without delay/forbidden slots.
    819   void Bc(MipsLabel* label, bool is_bare = false);  // R6
    820   void Balc(MipsLabel* label, bool is_bare = false);  // R6
    821   // R6-only compact branches with forbidden slots.
    822   void Beqc(Register rs, Register rt, MipsLabel* label, bool is_bare = false);  // R6
    823   void Bnec(Register rs, Register rt, MipsLabel* label, bool is_bare = false);  // R6
    824   void Beqzc(Register rt, MipsLabel* label, bool is_bare = false);  // R6
    825   void Bnezc(Register rt, MipsLabel* label, bool is_bare = false);  // R6
    826   void Bltzc(Register rt, MipsLabel* label, bool is_bare = false);  // R6
    827   void Bgezc(Register rt, MipsLabel* label, bool is_bare = false);  // R6
    828   void Blezc(Register rt, MipsLabel* label, bool is_bare = false);  // R6
    829   void Bgtzc(Register rt, MipsLabel* label, bool is_bare = false);  // R6
    830   void Bltc(Register rs, Register rt, MipsLabel* label, bool is_bare = false);  // R6
    831   void Bgec(Register rs, Register rt, MipsLabel* label, bool is_bare = false);  // R6
    832   void Bltuc(Register rs, Register rt, MipsLabel* label, bool is_bare = false);  // R6
    833   void Bgeuc(Register rs, Register rt, MipsLabel* label, bool is_bare = false);  // R6
    834   // R6-only branches with delay slots.
    835   void Bc1eqz(FRegister ft, MipsLabel* label, bool is_bare = false);  // R6
    836   void Bc1nez(FRegister ft, MipsLabel* label, bool is_bare = false);  // R6
    837 
    838   void EmitLoad(ManagedRegister m_dst, Register src_register, int32_t src_offset, size_t size);
    839   void AdjustBaseAndOffset(Register& base,
    840                            int32_t& offset,
    841                            bool is_doubleword,
    842                            bool is_float = false);
    843   void AdjustBaseOffsetAndElementSizeShift(Register& base,
    844                                            int32_t& offset,
    845                                            int& element_size_shift);
    846 
    847  private:
    848   // This will be used as an argument for loads/stores
    849   // when there is no need for implicit null checks.
    850   struct NoImplicitNullChecker {
    851     void operator()() const {}
    852   };
    853 
    854  public:
    855   template <typename ImplicitNullChecker = NoImplicitNullChecker>
    856   void StoreConstToOffset(StoreOperandType type,
    857                           int64_t value,
    858                           Register base,
    859                           int32_t offset,
    860                           Register temp,
    861                           ImplicitNullChecker null_checker = NoImplicitNullChecker()) {
    862     // We permit `base` and `temp` to coincide (however, we check that neither is AT),
    863     // in which case the `base` register may be overwritten in the process.
    864     CHECK_NE(temp, AT);  // Must not use AT as temp, so as not to overwrite the adjusted base.
    865     AdjustBaseAndOffset(base, offset, /* is_doubleword= */ (type == kStoreDoubleword));
    866     uint32_t low = Low32Bits(value);
    867     uint32_t high = High32Bits(value);
    868     Register reg;
    869     // If the adjustment left `base` unchanged and equal to `temp`, we can't use `temp`
    870     // to load and hold the value but we can use AT instead as AT hasn't been used yet.
    871     // Otherwise, `temp` can be used for the value. And if `temp` is the same as the
    872     // original `base` (that is, `base` prior to the adjustment), the original `base`
    873     // register will be overwritten.
    874     if (base == temp) {
    875       temp = AT;
    876     }
    877     if (low == 0) {
    878       reg = ZERO;
    879     } else {
    880       reg = temp;
    881       LoadConst32(reg, low);
    882     }
    883     switch (type) {
    884       case kStoreByte:
    885         Sb(reg, base, offset);
    886         break;
    887       case kStoreHalfword:
    888         Sh(reg, base, offset);
    889         break;
    890       case kStoreWord:
    891         Sw(reg, base, offset);
    892         break;
    893       case kStoreDoubleword:
    894         Sw(reg, base, offset);
    895         null_checker();
    896         if (high == 0) {
    897           reg = ZERO;
    898         } else {
    899           reg = temp;
    900           if (high != low) {
    901             LoadConst32(reg, high);
    902           }
    903         }
    904         Sw(reg, base, offset + kMipsWordSize);
    905         break;
    906       default:
    907         LOG(FATAL) << "UNREACHABLE";
    908     }
    909     if (type != kStoreDoubleword) {
    910       null_checker();
    911     }
    912   }
    913 
    914   template <typename ImplicitNullChecker = NoImplicitNullChecker>
    915   void LoadFromOffset(LoadOperandType type,
    916                       Register reg,
    917                       Register base,
    918                       int32_t offset,
    919                       ImplicitNullChecker null_checker = NoImplicitNullChecker()) {
    920     AdjustBaseAndOffset(base, offset, /* is_doubleword= */ (type == kLoadDoubleword));
    921     switch (type) {
    922       case kLoadSignedByte:
    923         Lb(reg, base, offset);
    924         break;
    925       case kLoadUnsignedByte:
    926         Lbu(reg, base, offset);
    927         break;
    928       case kLoadSignedHalfword:
    929         Lh(reg, base, offset);
    930         break;
    931       case kLoadUnsignedHalfword:
    932         Lhu(reg, base, offset);
    933         break;
    934       case kLoadWord:
    935         Lw(reg, base, offset);
    936         break;
    937       case kLoadDoubleword:
    938         if (reg == base) {
    939           // This will clobber the base when loading the lower register. Since we have to load the
    940           // higher register as well, this will fail. Solution: reverse the order.
    941           Lw(static_cast<Register>(reg + 1), base, offset + kMipsWordSize);
    942           null_checker();
    943           Lw(reg, base, offset);
    944         } else {
    945           Lw(reg, base, offset);
    946           null_checker();
    947           Lw(static_cast<Register>(reg + 1), base, offset + kMipsWordSize);
    948         }
    949         break;
    950       default:
    951         LOG(FATAL) << "UNREACHABLE";
    952     }
    953     if (type != kLoadDoubleword) {
    954       null_checker();
    955     }
    956   }
    957 
    958   template <typename ImplicitNullChecker = NoImplicitNullChecker>
    959   void LoadSFromOffset(FRegister reg,
    960                        Register base,
    961                        int32_t offset,
    962                        ImplicitNullChecker null_checker = NoImplicitNullChecker()) {
    963     AdjustBaseAndOffset(base, offset, /* is_doubleword= */ false, /* is_float= */ true);
    964     Lwc1(reg, base, offset);
    965     null_checker();
    966   }
    967 
    968   template <typename ImplicitNullChecker = NoImplicitNullChecker>
    969   void LoadDFromOffset(FRegister reg,
    970                        Register base,
    971                        int32_t offset,
    972                        ImplicitNullChecker null_checker = NoImplicitNullChecker()) {
    973     AdjustBaseAndOffset(base, offset, /* is_doubleword= */ true, /* is_float= */ true);
    974     if (IsAligned<kMipsDoublewordSize>(offset)) {
    975       Ldc1(reg, base, offset);
    976       null_checker();
    977     } else {
    978       if (Is32BitFPU()) {
    979         Lwc1(reg, base, offset);
    980         null_checker();
    981         Lwc1(static_cast<FRegister>(reg + 1), base, offset + kMipsWordSize);
    982       } else {
    983         // 64-bit FPU.
    984         Lwc1(reg, base, offset);
    985         null_checker();
    986         Lw(T8, base, offset + kMipsWordSize);
    987         Mthc1(T8, reg);
    988       }
    989     }
    990   }
    991 
    992   template <typename ImplicitNullChecker = NoImplicitNullChecker>
    993   void LoadQFromOffset(FRegister reg,
    994                        Register base,
    995                        int32_t offset,
    996                        ImplicitNullChecker null_checker = NoImplicitNullChecker()) {
    997     int element_size_shift = -1;
    998     AdjustBaseOffsetAndElementSizeShift(base, offset, element_size_shift);
    999     switch (element_size_shift) {
   1000       case TIMES_1: LdB(static_cast<VectorRegister>(reg), base, offset); break;
   1001       case TIMES_2: LdH(static_cast<VectorRegister>(reg), base, offset); break;
   1002       case TIMES_4: LdW(static_cast<VectorRegister>(reg), base, offset); break;
   1003       case TIMES_8: LdD(static_cast<VectorRegister>(reg), base, offset); break;
   1004       default:
   1005         LOG(FATAL) << "UNREACHABLE";
   1006     }
   1007     null_checker();
   1008   }
   1009 
   1010   template <typename ImplicitNullChecker = NoImplicitNullChecker>
   1011   void StoreToOffset(StoreOperandType type,
   1012                      Register reg,
   1013                      Register base,
   1014                      int32_t offset,
   1015                      ImplicitNullChecker null_checker = NoImplicitNullChecker()) {
   1016     // Must not use AT as `reg`, so as not to overwrite the value being stored
   1017     // with the adjusted `base`.
   1018     CHECK_NE(reg, AT);
   1019     AdjustBaseAndOffset(base, offset, /* is_doubleword= */ (type == kStoreDoubleword));
   1020     switch (type) {
   1021       case kStoreByte:
   1022         Sb(reg, base, offset);
   1023         break;
   1024       case kStoreHalfword:
   1025         Sh(reg, base, offset);
   1026         break;
   1027       case kStoreWord:
   1028         Sw(reg, base, offset);
   1029         break;
   1030       case kStoreDoubleword:
   1031         CHECK_NE(reg, base);
   1032         CHECK_NE(static_cast<Register>(reg + 1), base);
   1033         Sw(reg, base, offset);
   1034         null_checker();
   1035         Sw(static_cast<Register>(reg + 1), base, offset + kMipsWordSize);
   1036         break;
   1037       default:
   1038         LOG(FATAL) << "UNREACHABLE";
   1039     }
   1040     if (type != kStoreDoubleword) {
   1041       null_checker();
   1042     }
   1043   }
   1044 
   1045   template <typename ImplicitNullChecker = NoImplicitNullChecker>
   1046   void StoreSToOffset(FRegister reg,
   1047                       Register base,
   1048                       int32_t offset,
   1049                       ImplicitNullChecker null_checker = NoImplicitNullChecker()) {
   1050     AdjustBaseAndOffset(base, offset, /* is_doubleword= */ false, /* is_float= */ true);
   1051     Swc1(reg, base, offset);
   1052     null_checker();
   1053   }
   1054 
   1055   template <typename ImplicitNullChecker = NoImplicitNullChecker>
   1056   void StoreDToOffset(FRegister reg,
   1057                       Register base,
   1058                       int32_t offset,
   1059                       ImplicitNullChecker null_checker = NoImplicitNullChecker()) {
   1060     AdjustBaseAndOffset(base, offset, /* is_doubleword= */ true, /* is_float= */ true);
   1061     if (IsAligned<kMipsDoublewordSize>(offset)) {
   1062       Sdc1(reg, base, offset);
   1063       null_checker();
   1064     } else {
   1065       if (Is32BitFPU()) {
   1066         Swc1(reg, base, offset);
   1067         null_checker();
   1068         Swc1(static_cast<FRegister>(reg + 1), base, offset + kMipsWordSize);
   1069       } else {
   1070         // 64-bit FPU.
   1071         Mfhc1(T8, reg);
   1072         Swc1(reg, base, offset);
   1073         null_checker();
   1074         Sw(T8, base, offset + kMipsWordSize);
   1075       }
   1076     }
   1077   }
   1078 
   1079   template <typename ImplicitNullChecker = NoImplicitNullChecker>
   1080   void StoreQToOffset(FRegister reg,
   1081                       Register base,
   1082                       int32_t offset,
   1083                       ImplicitNullChecker null_checker = NoImplicitNullChecker()) {
   1084     int element_size_shift = -1;
   1085     AdjustBaseOffsetAndElementSizeShift(base, offset, element_size_shift);
   1086     switch (element_size_shift) {
   1087       case TIMES_1: StB(static_cast<VectorRegister>(reg), base, offset); break;
   1088       case TIMES_2: StH(static_cast<VectorRegister>(reg), base, offset); break;
   1089       case TIMES_4: StW(static_cast<VectorRegister>(reg), base, offset); break;
   1090       case TIMES_8: StD(static_cast<VectorRegister>(reg), base, offset); break;
   1091       default:
   1092         LOG(FATAL) << "UNREACHABLE";
   1093     }
   1094     null_checker();
   1095   }
   1096 
   1097   void LoadFromOffset(LoadOperandType type, Register reg, Register base, int32_t offset);
   1098   void LoadSFromOffset(FRegister reg, Register base, int32_t offset);
   1099   void LoadDFromOffset(FRegister reg, Register base, int32_t offset);
   1100   void LoadQFromOffset(FRegister reg, Register base, int32_t offset);
   1101   void StoreToOffset(StoreOperandType type, Register reg, Register base, int32_t offset);
   1102   void StoreSToOffset(FRegister reg, Register base, int32_t offset);
   1103   void StoreDToOffset(FRegister reg, Register base, int32_t offset);
   1104   void StoreQToOffset(FRegister reg, Register base, int32_t offset);
   1105 
   1106   // Emit data (e.g. encoded instruction or immediate) to the instruction stream.
   1107   void Emit(uint32_t value);
   1108 
   1109   // Push/pop composite routines.
   1110   void Push(Register rs);
   1111   void Pop(Register rd);
   1112   void PopAndReturn(Register rd, Register rt);
   1113 
   1114   //
   1115   // Heap poisoning.
   1116   //
   1117 
   1118   // Poison a heap reference contained in `src` and store it in `dst`.
   1119   void PoisonHeapReference(Register dst, Register src) {
   1120     // dst = -src.
   1121     Subu(dst, ZERO, src);
   1122   }
   1123   // Poison a heap reference contained in `reg`.
   1124   void PoisonHeapReference(Register reg) {
   1125     // reg = -reg.
   1126     PoisonHeapReference(reg, reg);
   1127   }
   1128   // Unpoison a heap reference contained in `reg`.
   1129   void UnpoisonHeapReference(Register reg) {
   1130     // reg = -reg.
   1131     Subu(reg, ZERO, reg);
   1132   }
   1133   // Poison a heap reference contained in `reg` if heap poisoning is enabled.
   1134   void MaybePoisonHeapReference(Register reg) {
   1135     if (kPoisonHeapReferences) {
   1136       PoisonHeapReference(reg);
   1137     }
   1138   }
   1139   // Unpoison a heap reference contained in `reg` if heap poisoning is enabled.
   1140   void MaybeUnpoisonHeapReference(Register reg) {
   1141     if (kPoisonHeapReferences) {
   1142       UnpoisonHeapReference(reg);
   1143     }
   1144   }
   1145 
   1146   void Bind(Label* label) override {
   1147     Bind(down_cast<MipsLabel*>(label));
   1148   }
   1149   void Jump(Label* label ATTRIBUTE_UNUSED) override {
   1150     UNIMPLEMENTED(FATAL) << "Do not use Jump for MIPS";
   1151   }
   1152 
   1153   // Don't warn about a different virtual Bind/Jump in the base class.
   1154   using JNIBase::Bind;
   1155   using JNIBase::Jump;
   1156 
   1157   // Create a new label that can be used with Jump/Bind calls.
   1158   std::unique_ptr<JNIMacroLabel> CreateLabel() override {
   1159     LOG(FATAL) << "Not implemented on MIPS32";
   1160     UNREACHABLE();
   1161   }
   1162   // Emit an unconditional jump to the label.
   1163   void Jump(JNIMacroLabel* label ATTRIBUTE_UNUSED) override {
   1164     LOG(FATAL) << "Not implemented on MIPS32";
   1165     UNREACHABLE();
   1166   }
   1167   // Emit a conditional jump to the label by applying a unary condition test to the register.
   1168   void Jump(JNIMacroLabel* label ATTRIBUTE_UNUSED,
   1169             JNIMacroUnaryCondition cond ATTRIBUTE_UNUSED,
   1170             ManagedRegister test ATTRIBUTE_UNUSED) override {
   1171     LOG(FATAL) << "Not implemented on MIPS32";
   1172     UNREACHABLE();
   1173   }
   1174 
   1175   // Code at this offset will serve as the target for the Jump call.
   1176   void Bind(JNIMacroLabel* label ATTRIBUTE_UNUSED) override {
   1177     LOG(FATAL) << "Not implemented on MIPS32";
   1178     UNREACHABLE();
   1179   }
   1180 
   1181   // Create a new literal with a given value.
   1182   // NOTE: Force the template parameter to be explicitly specified.
   1183   template <typename T>
   1184   Literal* NewLiteral(typename Identity<T>::type value) {
   1185     static_assert(std::is_integral<T>::value, "T must be an integral type.");
   1186     return NewLiteral(sizeof(value), reinterpret_cast<const uint8_t*>(&value));
   1187   }
   1188 
   1189   // Load label address using PC-relative addressing.
   1190   // To be used with data labels in the literal / jump table area only and not
   1191   // with regular code labels.
   1192   //
   1193   // For R6 base_reg must be ZERO.
   1194   //
   1195   // On R2 there are two possible uses w.r.t. base_reg:
   1196   //
   1197   // - base_reg = ZERO:
   1198   //   The NAL instruction will be generated as part of the load and it will
   1199   //   clobber the RA register.
   1200   //
   1201   // - base_reg != ZERO:
   1202   //   The RA-clobbering NAL instruction won't be generated as part of the load.
   1203   //   The label pc_rel_base_label_ must be bound (with BindPcRelBaseLabel())
   1204   //   and base_reg must hold the address of the label. Example:
   1205   //     __ Nal();
   1206   //     __ Move(S3, RA);
   1207   //     __ BindPcRelBaseLabel();  // S3 holds the address of pc_rel_base_label_.
   1208   //     __ LoadLabelAddress(A0, S3, label1);
   1209   //     __ LoadLabelAddress(A1, S3, label2);
   1210   //     __ LoadLiteral(V0, S3, literal1);
   1211   //     __ LoadLiteral(V1, S3, literal2);
   1212   void LoadLabelAddress(Register dest_reg, Register base_reg, MipsLabel* label);
   1213 
   1214   // Create a new literal with the given data.
   1215   Literal* NewLiteral(size_t size, const uint8_t* data);
   1216 
   1217   // Load literal using PC-relative addressing.
   1218   // See the above comments for LoadLabelAddress() on the value of base_reg.
   1219   void LoadLiteral(Register dest_reg, Register base_reg, Literal* literal);
   1220 
   1221   // Create a jump table for the given labels that will be emitted when finalizing.
   1222   // When the table is emitted, offsets will be relative to the location of the table.
   1223   // The table location is determined by the location of its label (the label precedes
   1224   // the table data) and should be loaded using LoadLabelAddress().
   1225   JumpTable* CreateJumpTable(std::vector<MipsLabel*>&& labels);
   1226 
   1227   //
   1228   // Overridden common assembler high-level functionality.
   1229   //
   1230 
   1231   // Emit code that will create an activation on the stack.
   1232   void BuildFrame(size_t frame_size,
   1233                   ManagedRegister method_reg,
   1234                   ArrayRef<const ManagedRegister> callee_save_regs,
   1235                   const ManagedRegisterEntrySpills& entry_spills) override;
   1236 
   1237   // Emit code that will remove an activation from the stack.
   1238   void RemoveFrame(size_t frame_size,
   1239                    ArrayRef<const ManagedRegister> callee_save_regs,
   1240                    bool may_suspend) override;
   1241 
   1242   void IncreaseFrameSize(size_t adjust) override;
   1243   void DecreaseFrameSize(size_t adjust) override;
   1244 
   1245   // Store routines.
   1246   void Store(FrameOffset offs, ManagedRegister msrc, size_t size) override;
   1247   void StoreRef(FrameOffset dest, ManagedRegister msrc) override;
   1248   void StoreRawPtr(FrameOffset dest, ManagedRegister msrc) override;
   1249 
   1250   void StoreImmediateToFrame(FrameOffset dest, uint32_t imm, ManagedRegister mscratch) override;
   1251 
   1252   void StoreStackOffsetToThread(ThreadOffset32 thr_offs,
   1253                                 FrameOffset fr_offs,
   1254                                 ManagedRegister mscratch) override;
   1255 
   1256   void StoreStackPointerToThread(ThreadOffset32 thr_offs) override;
   1257 
   1258   void StoreSpanning(FrameOffset dest,
   1259                      ManagedRegister msrc,
   1260                      FrameOffset in_off,
   1261                      ManagedRegister mscratch) override;
   1262 
   1263   // Load routines.
   1264   void Load(ManagedRegister mdest, FrameOffset src, size_t size) override;
   1265 
   1266   void LoadFromThread(ManagedRegister mdest, ThreadOffset32 src, size_t size) override;
   1267 
   1268   void LoadRef(ManagedRegister dest, FrameOffset src) override;
   1269 
   1270   void LoadRef(ManagedRegister mdest,
   1271                ManagedRegister base,
   1272                MemberOffset offs,
   1273                bool unpoison_reference) override;
   1274 
   1275   void LoadRawPtr(ManagedRegister mdest, ManagedRegister base, Offset offs) override;
   1276 
   1277   void LoadRawPtrFromThread(ManagedRegister mdest, ThreadOffset32 offs) override;
   1278 
   1279   // Copying routines.
   1280   void Move(ManagedRegister mdest, ManagedRegister msrc, size_t size) override;
   1281 
   1282   void CopyRawPtrFromThread(FrameOffset fr_offs,
   1283                             ThreadOffset32 thr_offs,
   1284                             ManagedRegister mscratch) override;
   1285 
   1286   void CopyRawPtrToThread(ThreadOffset32 thr_offs,
   1287                           FrameOffset fr_offs,
   1288                           ManagedRegister mscratch) override;
   1289 
   1290   void CopyRef(FrameOffset dest, FrameOffset src, ManagedRegister mscratch) override;
   1291 
   1292   void Copy(FrameOffset dest, FrameOffset src, ManagedRegister mscratch, size_t size) override;
   1293 
   1294   void Copy(FrameOffset dest,
   1295             ManagedRegister src_base,
   1296             Offset src_offset,
   1297             ManagedRegister mscratch,
   1298             size_t size) override;
   1299 
   1300   void Copy(ManagedRegister dest_base,
   1301             Offset dest_offset,
   1302             FrameOffset src,
   1303             ManagedRegister mscratch,
   1304             size_t size) override;
   1305 
   1306   void Copy(FrameOffset dest,
   1307             FrameOffset src_base,
   1308             Offset src_offset,
   1309             ManagedRegister mscratch,
   1310             size_t size) override;
   1311 
   1312   void Copy(ManagedRegister dest,
   1313             Offset dest_offset,
   1314             ManagedRegister src,
   1315             Offset src_offset,
   1316             ManagedRegister mscratch,
   1317             size_t size) override;
   1318 
   1319   void Copy(FrameOffset dest,
   1320             Offset dest_offset,
   1321             FrameOffset src,
   1322             Offset src_offset,
   1323             ManagedRegister mscratch,
   1324             size_t size) override;
   1325 
   1326   void MemoryBarrier(ManagedRegister) override;
   1327 
   1328   // Sign extension.
   1329   void SignExtend(ManagedRegister mreg, size_t size) override;
   1330 
   1331   // Zero extension.
   1332   void ZeroExtend(ManagedRegister mreg, size_t size) override;
   1333 
   1334   // Exploit fast access in managed code to Thread::Current().
   1335   void GetCurrentThread(ManagedRegister tr) override;
   1336   void GetCurrentThread(FrameOffset dest_offset, ManagedRegister mscratch) override;
   1337 
   1338   // Set up out_reg to hold a Object** into the handle scope, or to be null if the
   1339   // value is null and null_allowed. in_reg holds a possibly stale reference
   1340   // that can be used to avoid loading the handle scope entry to see if the value is
   1341   // null.
   1342   void CreateHandleScopeEntry(ManagedRegister out_reg,
   1343                               FrameOffset handlescope_offset,
   1344                               ManagedRegister in_reg,
   1345                               bool null_allowed) override;
   1346 
   1347   // Set up out_off to hold a Object** into the handle scope, or to be null if the
   1348   // value is null and null_allowed.
   1349   void CreateHandleScopeEntry(FrameOffset out_off,
   1350                               FrameOffset handlescope_offset,
   1351                               ManagedRegister mscratch,
   1352                               bool null_allowed) override;
   1353 
   1354   // src holds a handle scope entry (Object**) load this into dst.
   1355   void LoadReferenceFromHandleScope(ManagedRegister dst, ManagedRegister src) override;
   1356 
   1357   // Heap::VerifyObject on src. In some cases (such as a reference to this) we
   1358   // know that src may not be null.
   1359   void VerifyObject(ManagedRegister src, bool could_be_null) override;
   1360   void VerifyObject(FrameOffset src, bool could_be_null) override;
   1361 
   1362   // Call to address held at [base+offset].
   1363   void Call(ManagedRegister base, Offset offset, ManagedRegister mscratch) override;
   1364   void Call(FrameOffset base, Offset offset, ManagedRegister mscratch) override;
   1365   void CallFromThread(ThreadOffset32 offset, ManagedRegister mscratch) override;
   1366 
   1367   // Generate code to check if Thread::Current()->exception_ is non-null
   1368   // and branch to a ExceptionSlowPath if it is.
   1369   void ExceptionPoll(ManagedRegister mscratch, size_t stack_adjust) override;
   1370 
   1371   // Emit slow paths queued during assembly and promote short branches to long if needed.
   1372   void FinalizeCode() override;
   1373 
   1374   // Emit branches and finalize all instructions.
   1375   void FinalizeInstructions(const MemoryRegion& region) override;
   1376 
   1377   // Returns the (always-)current location of a label (can be used in class CodeGeneratorMIPS,
   1378   // must be used instead of MipsLabel::GetPosition()).
   1379   uint32_t GetLabelLocation(const MipsLabel* label) const;
   1380 
   1381   // Get the final position of a label after local fixup based on the old position
   1382   // recorded before FinalizeCode().
   1383   uint32_t GetAdjustedPosition(uint32_t old_position);
   1384 
   1385   // R2 doesn't have PC-relative addressing, which we need to access literals. We simulate it by
   1386   // reading the PC value into a general-purpose register with the NAL instruction and then loading
   1387   // literals through this base register. The code generator calls this method (at most once per
   1388   // method being compiled) to bind a label to the location for which the PC value is acquired.
   1389   // The assembler then computes literal offsets relative to this label.
   1390   void BindPcRelBaseLabel();
   1391 
   1392   // Returns the location of the label bound with BindPcRelBaseLabel().
   1393   uint32_t GetPcRelBaseLabelLocation() const;
   1394 
   1395   // Note that PC-relative literal loads are handled as pseudo branches because they need very
   1396   // similar relocation and may similarly expand in size to accomodate for larger offsets relative
   1397   // to PC.
   1398   enum BranchCondition {
   1399     kCondLT,
   1400     kCondGE,
   1401     kCondLE,
   1402     kCondGT,
   1403     kCondLTZ,
   1404     kCondGEZ,
   1405     kCondLEZ,
   1406     kCondGTZ,
   1407     kCondEQ,
   1408     kCondNE,
   1409     kCondEQZ,
   1410     kCondNEZ,
   1411     kCondLTU,
   1412     kCondGEU,
   1413     kCondF,    // Floating-point predicate false.
   1414     kCondT,    // Floating-point predicate true.
   1415     kUncond,
   1416   };
   1417   friend std::ostream& operator<<(std::ostream& os, const BranchCondition& rhs);
   1418 
   1419   // Enables or disables instruction reordering (IOW, automatic filling of delay slots)
   1420   // similarly to ".set reorder" / ".set noreorder" in traditional MIPS assembly.
   1421   // Returns the last state, which may be useful for temporary enabling/disabling of
   1422   // reordering.
   1423   bool SetReorder(bool enable);
   1424 
   1425  private:
   1426   // Description of the last instruction in terms of input and output registers.
   1427   // Used to make the decision of moving the instruction into a delay slot.
   1428   struct DelaySlot {
   1429     DelaySlot();
   1430 
   1431     // Encoded instruction that may be used to fill the delay slot or 0
   1432     // (0 conveniently represents NOP).
   1433     uint32_t instruction_;
   1434 
   1435     // Input/output register masks.
   1436     InOutRegMasks masks_;
   1437 
   1438     // Label for patchable instructions to allow moving them into delay slots.
   1439     MipsLabel* patcher_label_;
   1440   };
   1441 
   1442   // Delay slot finite state machine's (DS FSM's) state. The FSM state is updated
   1443   // upon every new instruction and label generated. The FSM detects instructions
   1444   // suitable for delay slots and immediately preceded with labels. These are target
   1445   // instructions for branches. If an unconditional R2 branch does not get its delay
   1446   // slot filled with the immediately preceding instruction, it may instead get the
   1447   // slot filled with the target instruction (the branch will need its offset
   1448   // incremented past the target instruction). We call this "absorption". The FSM
   1449   // records PCs of the target instructions suitable for this optimization.
   1450   enum DsFsmState {
   1451     kExpectingLabel,
   1452     kExpectingInstruction,
   1453     kExpectingCommit
   1454   };
   1455   friend std::ostream& operator<<(std::ostream& os, const DsFsmState& rhs);
   1456 
   1457   class Branch {
   1458    public:
   1459     enum Type {
   1460       // R2 short branches (can be promoted to long).
   1461       kUncondBranch,
   1462       kCondBranch,
   1463       kCall,
   1464       // R2 short branches (can't be promoted to long), delay slots filled manually.
   1465       kBareUncondBranch,
   1466       kBareCondBranch,
   1467       kBareCall,
   1468       // R2 near label.
   1469       kLabel,
   1470       // R2 near literal.
   1471       kLiteral,
   1472       // R2 long branches.
   1473       kLongUncondBranch,
   1474       kLongCondBranch,
   1475       kLongCall,
   1476       // R2 far label.
   1477       kFarLabel,
   1478       // R2 far literal.
   1479       kFarLiteral,
   1480       // R6 short branches (can be promoted to long).
   1481       kR6UncondBranch,
   1482       kR6CondBranch,
   1483       kR6Call,
   1484       // R6 short branches (can't be promoted to long), forbidden/delay slots filled manually.
   1485       kR6BareUncondBranch,
   1486       kR6BareCondBranch,
   1487       kR6BareCall,
   1488       // R6 near label.
   1489       kR6Label,
   1490       // R6 near literal.
   1491       kR6Literal,
   1492       // R6 long branches.
   1493       kR6LongUncondBranch,
   1494       kR6LongCondBranch,
   1495       kR6LongCall,
   1496       // R6 far label.
   1497       kR6FarLabel,
   1498       // R6 far literal.
   1499       kR6FarLiteral,
   1500     };
   1501     // Bit sizes of offsets defined as enums to minimize chance of typos.
   1502     enum OffsetBits {
   1503       kOffset16 = 16,
   1504       kOffset18 = 18,
   1505       kOffset21 = 21,
   1506       kOffset23 = 23,
   1507       kOffset28 = 28,
   1508       kOffset32 = 32,
   1509     };
   1510 
   1511     static constexpr uint32_t kUnresolved = 0xffffffff;  // Unresolved target_
   1512     static constexpr int32_t kMaxBranchLength = 32;
   1513     static constexpr int32_t kMaxBranchSize = kMaxBranchLength * sizeof(uint32_t);
   1514     // The following two instruction encodings can never legally occur in branch delay
   1515     // slots and are used as markers.
   1516     //
   1517     // kUnfilledDelaySlot means that the branch may use either the preceding or the target
   1518     // instruction to fill its delay slot (the latter is only possible with unconditional
   1519     // R2 branches and is termed here as "absorption").
   1520     static constexpr uint32_t kUnfilledDelaySlot = 0x10000000;  // beq zero, zero, 0.
   1521     // kUnfillableDelaySlot means that the branch cannot use an instruction (other than NOP)
   1522     // to fill its delay slot. This is only used for unconditional R2 branches to prevent
   1523     // absorption of the target instruction when reordering is disabled.
   1524     static constexpr uint32_t kUnfillableDelaySlot = 0x13FF0000;  // beq ra, ra, 0.
   1525 
   1526     struct BranchInfo {
   1527       // Branch length as a number of 4-byte-long instructions.
   1528       uint32_t length;
   1529       // Ordinal number (0-based) of the first (or the only) instruction that contains the branch's
   1530       // PC-relative offset (or its most significant 16-bit half, which goes first).
   1531       uint32_t instr_offset;
   1532       // Different MIPS instructions with PC-relative offsets apply said offsets to slightly
   1533       // different origins, e.g. to PC or PC+4. Encode the origin distance (as a number of 4-byte
   1534       // instructions) from the instruction containing the offset.
   1535       uint32_t pc_org;
   1536       // How large (in bits) a PC-relative offset can be for a given type of branch (kR6CondBranch
   1537       // and kR6BareCondBranch are an exception: use kOffset23 for beqzc/bnezc).
   1538       OffsetBits offset_size;
   1539       // Some MIPS instructions with PC-relative offsets shift the offset by 2. Encode the shift
   1540       // count.
   1541       int offset_shift;
   1542     };
   1543     static const BranchInfo branch_info_[/* Type */];
   1544 
   1545     // Unconditional branch or call.
   1546     Branch(bool is_r6, uint32_t location, uint32_t target, bool is_call, bool is_bare);
   1547     // Conditional branch.
   1548     Branch(bool is_r6,
   1549            uint32_t location,
   1550            uint32_t target,
   1551            BranchCondition condition,
   1552            Register lhs_reg,
   1553            Register rhs_reg,
   1554            bool is_bare);
   1555     // Label address (in literal area) or literal.
   1556     Branch(bool is_r6,
   1557            uint32_t location,
   1558            Register dest_reg,
   1559            Register base_reg,
   1560            Type label_or_literal_type);
   1561 
   1562     // Some conditional branches with lhs = rhs are effectively NOPs, while some
   1563     // others are effectively unconditional. MIPSR6 conditional branches require lhs != rhs.
   1564     // So, we need a way to identify such branches in order to emit no instructions for them
   1565     // or change them to unconditional.
   1566     static bool IsNop(BranchCondition condition, Register lhs, Register rhs);
   1567     static bool IsUncond(BranchCondition condition, Register lhs, Register rhs);
   1568 
   1569     static BranchCondition OppositeCondition(BranchCondition cond);
   1570 
   1571     Type GetType() const;
   1572     BranchCondition GetCondition() const;
   1573     Register GetLeftRegister() const;
   1574     Register GetRightRegister() const;
   1575     uint32_t GetTarget() const;
   1576     uint32_t GetLocation() const;
   1577     uint32_t GetOldLocation() const;
   1578     uint32_t GetPrecedingInstructionLength(Type type) const;
   1579     uint32_t GetPrecedingInstructionSize(Type type) const;
   1580     uint32_t GetLength() const;
   1581     uint32_t GetOldLength() const;
   1582     uint32_t GetSize() const;
   1583     uint32_t GetOldSize() const;
   1584     uint32_t GetEndLocation() const;
   1585     uint32_t GetOldEndLocation() const;
   1586     bool IsBare() const;
   1587     bool IsLong() const;
   1588     bool IsResolved() const;
   1589 
   1590     // Various helpers for branch delay slot management.
   1591     bool CanHaveDelayedInstruction(const DelaySlot& delay_slot) const;
   1592     void SetDelayedInstruction(uint32_t instruction, MipsLabel* patcher_label = nullptr);
   1593     uint32_t GetDelayedInstruction() const;
   1594     MipsLabel* GetPatcherLabel() const;
   1595     void DecrementLocations();
   1596 
   1597     // Returns the bit size of the signed offset that the branch instruction can handle.
   1598     OffsetBits GetOffsetSize() const;
   1599 
   1600     // Calculates the distance between two byte locations in the assembler buffer and
   1601     // returns the number of bits needed to represent the distance as a signed integer.
   1602     //
   1603     // Branch instructions have signed offsets of 16, 19 (addiupc), 21 (beqzc/bnezc),
   1604     // and 26 (bc) bits, which are additionally shifted left 2 positions at run time.
   1605     //
   1606     // Composite branches (made of several instructions) with longer reach have 32-bit
   1607     // offsets encoded as 2 16-bit "halves" in two instructions (high half goes first).
   1608     // The composite branches cover the range of PC + +/-2GB on MIPS32 CPUs. However,
   1609     // the range is not end-to-end on MIPS64 (unless addresses are forced to zero- or
   1610     // sign-extend from 32 to 64 bits by the appropriate CPU configuration).
   1611     // Consider the following implementation of a long unconditional branch, for
   1612     // example:
   1613     //
   1614     //   auipc at, offset_31_16  // at = pc + sign_extend(offset_31_16) << 16
   1615     //   jic   at, offset_15_0   // pc = at + sign_extend(offset_15_0)
   1616     //
   1617     // Both of the above instructions take 16-bit signed offsets as immediate operands.
   1618     // When bit 15 of offset_15_0 is 1, it effectively causes subtraction of 0x10000
   1619     // due to sign extension. This must be compensated for by incrementing offset_31_16
   1620     // by 1. offset_31_16 can only be incremented by 1 if it's not 0x7FFF. If it is
   1621     // 0x7FFF, adding 1 will overflow the positive offset into the negative range.
   1622     // Therefore, the long branch range is something like from PC - 0x80000000 to
   1623     // PC + 0x7FFF7FFF, IOW, shorter by 32KB on one side.
   1624     //
   1625     // The returned values are therefore: 18, 21, 23, 28 and 32. There's also a special
   1626     // case with the addiu instruction and a 16 bit offset.
   1627     static OffsetBits GetOffsetSizeNeeded(uint32_t location, uint32_t target);
   1628 
   1629     // Resolve a branch when the target is known.
   1630     void Resolve(uint32_t target);
   1631 
   1632     // Relocate a branch by a given delta if needed due to expansion of this or another
   1633     // branch at a given location by this delta (just changes location_ and target_).
   1634     void Relocate(uint32_t expand_location, uint32_t delta);
   1635 
   1636     // If the branch is short, changes its type to long.
   1637     void PromoteToLong();
   1638 
   1639     // If necessary, updates the type by promoting a short branch to a long branch
   1640     // based on the branch location and target. Returns the amount (in bytes) by
   1641     // which the branch size has increased.
   1642     // max_short_distance caps the maximum distance between location_ and target_
   1643     // that is allowed for short branches. This is for debugging/testing purposes.
   1644     // max_short_distance = 0 forces all short branches to become long.
   1645     // Use the implicit default argument when not debugging/testing.
   1646     uint32_t PromoteIfNeeded(uint32_t location,
   1647                              uint32_t max_short_distance = std::numeric_limits<uint32_t>::max());
   1648 
   1649     // Returns the location of the instruction(s) containing the offset.
   1650     uint32_t GetOffsetLocation() const;
   1651 
   1652     // Calculates and returns the offset ready for encoding in the branch instruction(s).
   1653     uint32_t GetOffset(uint32_t location) const;
   1654 
   1655    private:
   1656     // Completes branch construction by determining and recording its type.
   1657     void InitializeType(Type initial_type, bool is_r6);
   1658     // Helper for the above.
   1659     void InitShortOrLong(OffsetBits ofs_size, Type short_type, Type long_type);
   1660 
   1661     uint32_t old_location_;         // Offset into assembler buffer in bytes.
   1662     uint32_t location_;             // Offset into assembler buffer in bytes.
   1663     uint32_t target_;               // Offset into assembler buffer in bytes.
   1664 
   1665     uint32_t lhs_reg_;              // Left-hand side register in conditional branches or
   1666                                     // FPU condition code. Destination register in literals.
   1667     uint32_t rhs_reg_;              // Right-hand side register in conditional branches.
   1668                                     // Base register in literals (ZERO on R6).
   1669     BranchCondition condition_;     // Condition for conditional branches.
   1670 
   1671     Type type_;                     // Current type of the branch.
   1672     Type old_type_;                 // Initial type of the branch.
   1673 
   1674     uint32_t delayed_instruction_;  // Encoded instruction for the delay slot or
   1675                                     // kUnfilledDelaySlot if none but fillable or
   1676                                     // kUnfillableDelaySlot if none and unfillable
   1677                                     // (the latter is only used for unconditional R2
   1678                                     // branches).
   1679 
   1680     MipsLabel* patcher_label_;      // Patcher label for the instruction in the delay slot.
   1681   };
   1682   friend std::ostream& operator<<(std::ostream& os, const Branch::Type& rhs);
   1683   friend std::ostream& operator<<(std::ostream& os, const Branch::OffsetBits& rhs);
   1684 
   1685   uint32_t EmitR(int opcode, Register rs, Register rt, Register rd, int shamt, int funct);
   1686   uint32_t EmitI(int opcode, Register rs, Register rt, uint16_t imm);
   1687   uint32_t EmitI21(int opcode, Register rs, uint32_t imm21);
   1688   uint32_t EmitI26(int opcode, uint32_t imm26);
   1689   uint32_t EmitFR(int opcode, int fmt, FRegister ft, FRegister fs, FRegister fd, int funct);
   1690   uint32_t EmitFI(int opcode, int fmt, FRegister rt, uint16_t imm);
   1691   void EmitBcondR2(BranchCondition cond, Register rs, Register rt, uint16_t imm16);
   1692   void EmitBcondR6(BranchCondition cond, Register rs, Register rt, uint32_t imm16_21);
   1693   uint32_t EmitMsa3R(int operation,
   1694                      int df,
   1695                      VectorRegister wt,
   1696                      VectorRegister ws,
   1697                      VectorRegister wd,
   1698                      int minor_opcode);
   1699   uint32_t EmitMsaBIT(int operation,
   1700                       int df_m,
   1701                       VectorRegister ws,
   1702                       VectorRegister wd,
   1703                       int minor_opcode);
   1704   uint32_t EmitMsaELM(int operation,
   1705                       int df_n,
   1706                       VectorRegister ws,
   1707                       VectorRegister wd,
   1708                       int minor_opcode);
   1709   uint32_t EmitMsaMI10(int s10, Register rs, VectorRegister wd, int minor_opcode, int df);
   1710   uint32_t EmitMsaI10(int operation, int df, int i10, VectorRegister wd, int minor_opcode);
   1711   uint32_t EmitMsa2R(int operation, int df, VectorRegister ws, VectorRegister wd, int minor_opcode);
   1712   uint32_t EmitMsa2RF(int operation,
   1713                       int df,
   1714                       VectorRegister ws,
   1715                       VectorRegister wd,
   1716                       int minor_opcode);
   1717 
   1718   void Buncond(MipsLabel* label, bool is_r6, bool is_bare);
   1719   void Bcond(MipsLabel* label,
   1720              bool is_r6,
   1721              bool is_bare,
   1722              BranchCondition condition,
   1723              Register lhs,
   1724              Register rhs = ZERO);
   1725   void Call(MipsLabel* label, bool is_r6, bool is_bare);
   1726   void FinalizeLabeledBranch(MipsLabel* label);
   1727 
   1728   // Various helpers for branch delay slot management.
   1729   InOutRegMasks& DsFsmInstr(uint32_t instruction, MipsLabel* patcher_label = nullptr);
   1730   void DsFsmInstrNop(uint32_t instruction);
   1731   void DsFsmLabel();
   1732   void DsFsmCommitLabel();
   1733   void DsFsmDropLabel();
   1734   void MoveInstructionToDelaySlot(Branch& branch);
   1735   bool CanExchangeWithSlt(Register rs, Register rt) const;
   1736   void ExchangeWithSlt(const DelaySlot& forwarded_slot);
   1737   void GenerateSltForCondBranch(bool unsigned_slt, Register rs, Register rt);
   1738 
   1739   Branch* GetBranch(uint32_t branch_id);
   1740   const Branch* GetBranch(uint32_t branch_id) const;
   1741   uint32_t GetBranchLocationOrPcRelBase(const MipsAssembler::Branch* branch) const;
   1742   uint32_t GetBranchOrPcRelBaseForEncoding(const MipsAssembler::Branch* branch) const;
   1743   void BindRelativeToPrecedingBranch(MipsLabel* label,
   1744                                      uint32_t prev_branch_id_plus_one,
   1745                                      uint32_t position);
   1746 
   1747   void EmitLiterals();
   1748   void ReserveJumpTableSpace();
   1749   void EmitJumpTables();
   1750   void PromoteBranches();
   1751   void EmitBranch(uint32_t branch_id);
   1752   void EmitBranches();
   1753   void PatchCFI(size_t number_of_delayed_adjust_pcs);
   1754 
   1755   // Emits exception block.
   1756   void EmitExceptionPoll(MipsExceptionSlowPath* exception);
   1757 
   1758   bool HasMsa() const {
   1759     return has_msa_;
   1760   }
   1761 
   1762   bool IsR6() const {
   1763     if (isa_features_ != nullptr) {
   1764       return isa_features_->IsR6();
   1765     } else {
   1766       return false;
   1767     }
   1768   }
   1769 
   1770   bool Is32BitFPU() const {
   1771     if (isa_features_ != nullptr) {
   1772       return isa_features_->Is32BitFloatingPoint();
   1773     } else {
   1774       return true;
   1775     }
   1776   }
   1777 
   1778   // List of exception blocks to generate at the end of the code cache.
   1779   std::vector<MipsExceptionSlowPath> exception_blocks_;
   1780 
   1781   std::vector<Branch> branches_;
   1782 
   1783   // Whether appending instructions at the end of the buffer or overwriting the existing ones.
   1784   bool overwriting_;
   1785   // The current overwrite location.
   1786   uint32_t overwrite_location_;
   1787 
   1788   // Whether instruction reordering (IOW, automatic filling of delay slots) is enabled.
   1789   bool reordering_;
   1790   // Information about the last instruction that may be used to fill a branch delay slot.
   1791   DelaySlot delay_slot_;
   1792   // Delay slot FSM state.
   1793   DsFsmState ds_fsm_state_;
   1794   // PC of the current labeled target instruction.
   1795   uint32_t ds_fsm_target_pc_;
   1796   // PCs of labeled target instructions.
   1797   std::vector<uint32_t> ds_fsm_target_pcs_;
   1798 
   1799   // Use std::deque<> for literal labels to allow insertions at the end
   1800   // without invalidating pointers and references to existing elements.
   1801   ArenaDeque<Literal> literals_;
   1802 
   1803   // Jump table list.
   1804   ArenaDeque<JumpTable> jump_tables_;
   1805 
   1806   // There's no PC-relative addressing on MIPS32R2. So, in order to access literals relative to PC
   1807   // we get PC using the NAL instruction. This label marks the position within the assembler buffer
   1808   // that PC (from NAL) points to.
   1809   MipsLabel pc_rel_base_label_;
   1810 
   1811   // Data for GetAdjustedPosition(), see the description there.
   1812   uint32_t last_position_adjustment_;
   1813   uint32_t last_old_position_;
   1814   uint32_t last_branch_id_;
   1815 
   1816   const bool has_msa_;
   1817 
   1818   const MipsInstructionSetFeatures* isa_features_;
   1819 
   1820   DISALLOW_COPY_AND_ASSIGN(MipsAssembler);
   1821 };
   1822 
   1823 }  // namespace mips
   1824 }  // namespace art
   1825 
   1826 #endif  // ART_COMPILER_UTILS_MIPS_ASSEMBLER_MIPS_H_
   1827