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      1 // Copyright 2012 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef V8_MIPS_MACRO_ASSEMBLER_MIPS_H_
      6 #define V8_MIPS_MACRO_ASSEMBLER_MIPS_H_
      7 
      8 #include "src/assembler.h"
      9 #include "src/globals.h"
     10 #include "src/mips64/assembler-mips64.h"
     11 
     12 namespace v8 {
     13 namespace internal {
     14 
     15 // Give alias names to registers for calling conventions.
     16 const Register kReturnRegister0 = {Register::kCode_v0};
     17 const Register kReturnRegister1 = {Register::kCode_v1};
     18 const Register kReturnRegister2 = {Register::kCode_a0};
     19 const Register kJSFunctionRegister = {Register::kCode_a1};
     20 const Register kContextRegister = {Register::kCpRegister};
     21 const Register kAllocateSizeRegister = {Register::kCode_a0};
     22 const Register kInterpreterAccumulatorRegister = {Register::kCode_v0};
     23 const Register kInterpreterBytecodeOffsetRegister = {Register::kCode_t0};
     24 const Register kInterpreterBytecodeArrayRegister = {Register::kCode_t1};
     25 const Register kInterpreterDispatchTableRegister = {Register::kCode_t2};
     26 const Register kJavaScriptCallArgCountRegister = {Register::kCode_a0};
     27 const Register kJavaScriptCallNewTargetRegister = {Register::kCode_a3};
     28 const Register kRuntimeCallFunctionRegister = {Register::kCode_a1};
     29 const Register kRuntimeCallArgCountRegister = {Register::kCode_a0};
     30 
     31 // Forward declaration.
     32 class JumpTarget;
     33 
     34 // Reserved Register Usage Summary.
     35 //
     36 // Registers t8, t9, and at are reserved for use by the MacroAssembler.
     37 //
     38 // The programmer should know that the MacroAssembler may clobber these three,
     39 // but won't touch other registers except in special cases.
     40 //
     41 // Per the MIPS ABI, register t9 must be used for indirect function call
     42 // via 'jalr t9' or 'jr t9' instructions. This is relied upon by gcc when
     43 // trying to update gp register for position-independent-code. Whenever
     44 // MIPS generated code calls C code, it must be via t9 register.
     45 
     46 
     47 // Flags used for LeaveExitFrame function.
     48 enum LeaveExitFrameMode {
     49   EMIT_RETURN = true,
     50   NO_EMIT_RETURN = false
     51 };
     52 
     53 // Flags used for AllocateHeapNumber
     54 enum TaggingMode {
     55   // Tag the result.
     56   TAG_RESULT,
     57   // Don't tag
     58   DONT_TAG_RESULT
     59 };
     60 
     61 // Flags used for the ObjectToDoubleFPURegister function.
     62 enum ObjectToDoubleFlags {
     63   // No special flags.
     64   NO_OBJECT_TO_DOUBLE_FLAGS = 0,
     65   // Object is known to be a non smi.
     66   OBJECT_NOT_SMI = 1 << 0,
     67   // Don't load NaNs or infinities, branch to the non number case instead.
     68   AVOID_NANS_AND_INFINITIES = 1 << 1
     69 };
     70 
     71 // Allow programmer to use Branch Delay Slot of Branches, Jumps, Calls.
     72 enum BranchDelaySlot {
     73   USE_DELAY_SLOT,
     74   PROTECT
     75 };
     76 
     77 // Flags used for the li macro-assembler function.
     78 enum LiFlags {
     79   // If the constant value can be represented in just 16 bits, then
     80   // optimize the li to use a single instruction, rather than lui/ori/dsll
     81   // sequence.
     82   OPTIMIZE_SIZE = 0,
     83   // Always use 6 instructions (lui/ori/dsll sequence), even if the constant
     84   // could be loaded with just one, so that this value is patchable later.
     85   CONSTANT_SIZE = 1,
     86   // For address loads only 4 instruction are required. Used to mark
     87   // constant load that will be used as address without relocation
     88   // information. It ensures predictable code size, so specific sites
     89   // in code are patchable.
     90   ADDRESS_LOAD  = 2
     91 };
     92 
     93 
     94 enum RememberedSetAction { EMIT_REMEMBERED_SET, OMIT_REMEMBERED_SET };
     95 enum SmiCheck { INLINE_SMI_CHECK, OMIT_SMI_CHECK };
     96 enum PointersToHereCheck {
     97   kPointersToHereMaybeInteresting,
     98   kPointersToHereAreAlwaysInteresting
     99 };
    100 enum RAStatus { kRAHasNotBeenSaved, kRAHasBeenSaved };
    101 
    102 Register GetRegisterThatIsNotOneOf(Register reg1,
    103                                    Register reg2 = no_reg,
    104                                    Register reg3 = no_reg,
    105                                    Register reg4 = no_reg,
    106                                    Register reg5 = no_reg,
    107                                    Register reg6 = no_reg);
    108 
    109 bool AreAliased(Register reg1, Register reg2, Register reg3 = no_reg,
    110                 Register reg4 = no_reg, Register reg5 = no_reg,
    111                 Register reg6 = no_reg, Register reg7 = no_reg,
    112                 Register reg8 = no_reg, Register reg9 = no_reg,
    113                 Register reg10 = no_reg);
    114 
    115 
    116 // -----------------------------------------------------------------------------
    117 // Static helper functions.
    118 
    119 #if defined(V8_TARGET_LITTLE_ENDIAN)
    120 #define SmiWordOffset(offset) (offset + kPointerSize / 2)
    121 #else
    122 #define SmiWordOffset(offset) offset
    123 #endif
    124 
    125 
    126 inline MemOperand ContextMemOperand(Register context, int index) {
    127   return MemOperand(context, Context::SlotOffset(index));
    128 }
    129 
    130 
    131 inline MemOperand NativeContextMemOperand() {
    132   return ContextMemOperand(cp, Context::NATIVE_CONTEXT_INDEX);
    133 }
    134 
    135 
    136 // Generate a MemOperand for loading a field from an object.
    137 inline MemOperand FieldMemOperand(Register object, int offset) {
    138   return MemOperand(object, offset - kHeapObjectTag);
    139 }
    140 
    141 
    142 inline MemOperand UntagSmiMemOperand(Register rm, int offset) {
    143   // Assumes that Smis are shifted by 32 bits.
    144   STATIC_ASSERT(kSmiShift == 32);
    145   return MemOperand(rm, SmiWordOffset(offset));
    146 }
    147 
    148 
    149 inline MemOperand UntagSmiFieldMemOperand(Register rm, int offset) {
    150   return UntagSmiMemOperand(rm, offset - kHeapObjectTag);
    151 }
    152 
    153 
    154 // Generate a MemOperand for storing arguments 5..N on the stack
    155 // when calling CallCFunction().
    156 // TODO(plind): Currently ONLY used for O32. Should be fixed for
    157 //              n64, and used in RegExp code, and other places
    158 //              with more than 8 arguments.
    159 inline MemOperand CFunctionArgumentOperand(int index) {
    160   DCHECK(index > kCArgSlotCount);
    161   // Argument 5 takes the slot just past the four Arg-slots.
    162   int offset = (index - 5) * kPointerSize + kCArgsSlotsSize;
    163   return MemOperand(sp, offset);
    164 }
    165 
    166 
    167 // MacroAssembler implements a collection of frequently used macros.
    168 class MacroAssembler: public Assembler {
    169  public:
    170   MacroAssembler(Isolate* isolate, void* buffer, int size,
    171                  CodeObjectRequired create_code_object);
    172 
    173   // Arguments macros.
    174 #define COND_TYPED_ARGS Condition cond, Register r1, const Operand& r2
    175 #define COND_ARGS cond, r1, r2
    176 
    177   // Cases when relocation is not needed.
    178 #define DECLARE_NORELOC_PROTOTYPE(Name, target_type) \
    179   void Name(target_type target, BranchDelaySlot bd = PROTECT); \
    180   inline void Name(BranchDelaySlot bd, target_type target) { \
    181     Name(target, bd); \
    182   } \
    183   void Name(target_type target, \
    184             COND_TYPED_ARGS, \
    185             BranchDelaySlot bd = PROTECT); \
    186   inline void Name(BranchDelaySlot bd, \
    187                    target_type target, \
    188                    COND_TYPED_ARGS) { \
    189     Name(target, COND_ARGS, bd); \
    190   }
    191 
    192 #define DECLARE_BRANCH_PROTOTYPES(Name)   \
    193   DECLARE_NORELOC_PROTOTYPE(Name, Label*) \
    194   DECLARE_NORELOC_PROTOTYPE(Name, int32_t)
    195 
    196   DECLARE_BRANCH_PROTOTYPES(Branch)
    197   DECLARE_BRANCH_PROTOTYPES(BranchAndLink)
    198   DECLARE_BRANCH_PROTOTYPES(BranchShort)
    199 
    200 #undef DECLARE_BRANCH_PROTOTYPES
    201 #undef COND_TYPED_ARGS
    202 #undef COND_ARGS
    203 
    204 
    205   // Jump, Call, and Ret pseudo instructions implementing inter-working.
    206 #define COND_ARGS Condition cond = al, Register rs = zero_reg, \
    207   const Operand& rt = Operand(zero_reg), BranchDelaySlot bd = PROTECT
    208 
    209   void Jump(Register target, COND_ARGS);
    210   void Jump(intptr_t target, RelocInfo::Mode rmode, COND_ARGS);
    211   void Jump(Address target, RelocInfo::Mode rmode, COND_ARGS);
    212   void Jump(Handle<Code> code, RelocInfo::Mode rmode, COND_ARGS);
    213   static int CallSize(Register target, COND_ARGS);
    214   void Call(Register target, COND_ARGS);
    215   static int CallSize(Address target, RelocInfo::Mode rmode, COND_ARGS);
    216   void Call(Address target, RelocInfo::Mode rmode, COND_ARGS);
    217   int CallSize(Handle<Code> code,
    218                RelocInfo::Mode rmode = RelocInfo::CODE_TARGET,
    219                TypeFeedbackId ast_id = TypeFeedbackId::None(),
    220                COND_ARGS);
    221   void Call(Handle<Code> code,
    222             RelocInfo::Mode rmode = RelocInfo::CODE_TARGET,
    223             TypeFeedbackId ast_id = TypeFeedbackId::None(),
    224             COND_ARGS);
    225   void Ret(COND_ARGS);
    226   inline void Ret(BranchDelaySlot bd, Condition cond = al,
    227     Register rs = zero_reg, const Operand& rt = Operand(zero_reg)) {
    228     Ret(cond, rs, rt, bd);
    229   }
    230 
    231   bool IsNear(Label* L, Condition cond, int rs_reg);
    232 
    233   void Branch(Label* L,
    234               Condition cond,
    235               Register rs,
    236               Heap::RootListIndex index,
    237               BranchDelaySlot bdslot = PROTECT);
    238 
    239 // Number of instructions needed for calculation of switch table entry address
    240 #ifdef _MIPS_ARCH_MIPS64R6
    241   static const int kSwitchTablePrologueSize = 6;
    242 #else
    243   static const int kSwitchTablePrologueSize = 11;
    244 #endif
    245 
    246   // GetLabelFunction must be lambda '[](size_t index) -> Label*' or a
    247   // functor/function with 'Label *func(size_t index)' declaration.
    248   template <typename Func>
    249   void GenerateSwitchTable(Register index, size_t case_count,
    250                            Func GetLabelFunction);
    251 #undef COND_ARGS
    252 
    253   // Emit code that loads |parameter_index|'th parameter from the stack to
    254   // the register according to the CallInterfaceDescriptor definition.
    255   // |sp_to_caller_sp_offset_in_words| specifies the number of words pushed
    256   // below the caller's sp.
    257   template <class Descriptor>
    258   void LoadParameterFromStack(
    259       Register reg, typename Descriptor::ParameterIndices parameter_index,
    260       int sp_to_ra_offset_in_words = 0) {
    261     DCHECK(Descriptor::kPassLastArgsOnStack);
    262     UNIMPLEMENTED();
    263   }
    264 
    265   // Emit code to discard a non-negative number of pointer-sized elements
    266   // from the stack, clobbering only the sp register.
    267   void Drop(int count,
    268             Condition cond = cc_always,
    269             Register reg = no_reg,
    270             const Operand& op = Operand(no_reg));
    271 
    272   // Trivial case of DropAndRet that utilizes the delay slot and only emits
    273   // 2 instructions.
    274   void DropAndRet(int drop);
    275 
    276   void DropAndRet(int drop,
    277                   Condition cond,
    278                   Register reg,
    279                   const Operand& op);
    280 
    281   // Swap two registers.  If the scratch register is omitted then a slightly
    282   // less efficient form using xor instead of mov is emitted.
    283   void Swap(Register reg1, Register reg2, Register scratch = no_reg);
    284 
    285   void Call(Label* target);
    286 
    287   inline void Move(Register dst, Handle<Object> handle) { li(dst, handle); }
    288   inline void Move(Register dst, Smi* smi) { li(dst, Operand(smi)); }
    289 
    290   inline void Move(Register dst, Register src) {
    291     if (!dst.is(src)) {
    292       mov(dst, src);
    293     }
    294   }
    295 
    296   inline void Move_d(FPURegister dst, FPURegister src) {
    297     if (!dst.is(src)) {
    298       mov_d(dst, src);
    299     }
    300   }
    301 
    302   inline void Move_s(FPURegister dst, FPURegister src) {
    303     if (!dst.is(src)) {
    304       mov_s(dst, src);
    305     }
    306   }
    307 
    308   inline void Move(FPURegister dst, FPURegister src) { Move_d(dst, src); }
    309 
    310   inline void Move(Register dst_low, Register dst_high, FPURegister src) {
    311     mfc1(dst_low, src);
    312     mfhc1(dst_high, src);
    313   }
    314 
    315   inline void Move(Register dst, FPURegister src) { dmfc1(dst, src); }
    316 
    317   inline void Move(FPURegister dst, Register src) { dmtc1(src, dst); }
    318 
    319   inline void FmoveHigh(Register dst_high, FPURegister src) {
    320     mfhc1(dst_high, src);
    321   }
    322 
    323   inline void FmoveHigh(FPURegister dst, Register src_high) {
    324     mthc1(src_high, dst);
    325   }
    326 
    327   inline void FmoveLow(Register dst_low, FPURegister src) {
    328     mfc1(dst_low, src);
    329   }
    330 
    331   void FmoveLow(FPURegister dst, Register src_low);
    332 
    333   inline void Move(FPURegister dst, Register src_low, Register src_high) {
    334     mtc1(src_low, dst);
    335     mthc1(src_high, dst);
    336   }
    337 
    338   void Move(FPURegister dst, float imm);
    339   void Move(FPURegister dst, double imm);
    340 
    341   // Conditional move.
    342   void Movz(Register rd, Register rs, Register rt);
    343   void Movn(Register rd, Register rs, Register rt);
    344   void Movt(Register rd, Register rs, uint16_t cc = 0);
    345   void Movf(Register rd, Register rs, uint16_t cc = 0);
    346 
    347   void Clz(Register rd, Register rs);
    348 
    349   // Jump unconditionally to given label.
    350   // We NEED a nop in the branch delay slot, as it used by v8, for example in
    351   // CodeGenerator::ProcessDeferred().
    352   // Currently the branch delay slot is filled by the MacroAssembler.
    353   // Use rather b(Label) for code generation.
    354   void jmp(Label* L) {
    355     Branch(L);
    356   }
    357 
    358   void Load(Register dst, const MemOperand& src, Representation r);
    359   void Store(Register src, const MemOperand& dst, Representation r);
    360 
    361   void PushRoot(Heap::RootListIndex index) {
    362     LoadRoot(at, index);
    363     Push(at);
    364   }
    365 
    366   // Compare the object in a register to a value and jump if they are equal.
    367   void JumpIfRoot(Register with, Heap::RootListIndex index, Label* if_equal) {
    368     LoadRoot(at, index);
    369     Branch(if_equal, eq, with, Operand(at));
    370   }
    371 
    372   // Compare the object in a register to a value and jump if they are not equal.
    373   void JumpIfNotRoot(Register with, Heap::RootListIndex index,
    374                      Label* if_not_equal) {
    375     LoadRoot(at, index);
    376     Branch(if_not_equal, ne, with, Operand(at));
    377   }
    378 
    379   // Load an object from the root table.
    380   void LoadRoot(Register destination,
    381                 Heap::RootListIndex index);
    382   void LoadRoot(Register destination,
    383                 Heap::RootListIndex index,
    384                 Condition cond, Register src1, const Operand& src2);
    385 
    386   // Store an object to the root table.
    387   void StoreRoot(Register source,
    388                  Heap::RootListIndex index);
    389   void StoreRoot(Register source,
    390                  Heap::RootListIndex index,
    391                  Condition cond, Register src1, const Operand& src2);
    392 
    393   // ---------------------------------------------------------------------------
    394   // GC Support
    395 
    396   void IncrementalMarkingRecordWriteHelper(Register object,
    397                                            Register value,
    398                                            Register address);
    399 
    400   enum RememberedSetFinalAction {
    401     kReturnAtEnd,
    402     kFallThroughAtEnd
    403   };
    404 
    405 
    406   // Record in the remembered set the fact that we have a pointer to new space
    407   // at the address pointed to by the addr register.  Only works if addr is not
    408   // in new space.
    409   void RememberedSetHelper(Register object,  // Used for debug code.
    410                            Register addr,
    411                            Register scratch,
    412                            SaveFPRegsMode save_fp,
    413                            RememberedSetFinalAction and_then);
    414 
    415   void CheckPageFlag(Register object,
    416                      Register scratch,
    417                      int mask,
    418                      Condition cc,
    419                      Label* condition_met);
    420 
    421   // Check if object is in new space.  Jumps if the object is not in new space.
    422   // The register scratch can be object itself, but it will be clobbered.
    423   void JumpIfNotInNewSpace(Register object,
    424                            Register scratch,
    425                            Label* branch) {
    426     InNewSpace(object, scratch, eq, branch);
    427   }
    428 
    429   // Check if object is in new space.  Jumps if the object is in new space.
    430   // The register scratch can be object itself, but scratch will be clobbered.
    431   void JumpIfInNewSpace(Register object,
    432                         Register scratch,
    433                         Label* branch) {
    434     InNewSpace(object, scratch, ne, branch);
    435   }
    436 
    437   // Check if an object has a given incremental marking color.
    438   void HasColor(Register object,
    439                 Register scratch0,
    440                 Register scratch1,
    441                 Label* has_color,
    442                 int first_bit,
    443                 int second_bit);
    444 
    445   void JumpIfBlack(Register object,
    446                    Register scratch0,
    447                    Register scratch1,
    448                    Label* on_black);
    449 
    450   // Checks the color of an object.  If the object is white we jump to the
    451   // incremental marker.
    452   void JumpIfWhite(Register value, Register scratch1, Register scratch2,
    453                    Register scratch3, Label* value_is_white);
    454 
    455   // Notify the garbage collector that we wrote a pointer into an object.
    456   // |object| is the object being stored into, |value| is the object being
    457   // stored.  value and scratch registers are clobbered by the operation.
    458   // The offset is the offset from the start of the object, not the offset from
    459   // the tagged HeapObject pointer.  For use with FieldOperand(reg, off).
    460   void RecordWriteField(
    461       Register object,
    462       int offset,
    463       Register value,
    464       Register scratch,
    465       RAStatus ra_status,
    466       SaveFPRegsMode save_fp,
    467       RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
    468       SmiCheck smi_check = INLINE_SMI_CHECK,
    469       PointersToHereCheck pointers_to_here_check_for_value =
    470           kPointersToHereMaybeInteresting);
    471 
    472   // As above, but the offset has the tag presubtracted.  For use with
    473   // MemOperand(reg, off).
    474   inline void RecordWriteContextSlot(
    475       Register context,
    476       int offset,
    477       Register value,
    478       Register scratch,
    479       RAStatus ra_status,
    480       SaveFPRegsMode save_fp,
    481       RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
    482       SmiCheck smi_check = INLINE_SMI_CHECK,
    483       PointersToHereCheck pointers_to_here_check_for_value =
    484           kPointersToHereMaybeInteresting) {
    485     RecordWriteField(context,
    486                      offset + kHeapObjectTag,
    487                      value,
    488                      scratch,
    489                      ra_status,
    490                      save_fp,
    491                      remembered_set_action,
    492                      smi_check,
    493                      pointers_to_here_check_for_value);
    494   }
    495 
    496   // Notify the garbage collector that we wrote a code entry into a
    497   // JSFunction. Only scratch is clobbered by the operation.
    498   void RecordWriteCodeEntryField(Register js_function, Register code_entry,
    499                                  Register scratch);
    500 
    501   void RecordWriteForMap(
    502       Register object,
    503       Register map,
    504       Register dst,
    505       RAStatus ra_status,
    506       SaveFPRegsMode save_fp);
    507 
    508   // For a given |object| notify the garbage collector that the slot |address|
    509   // has been written.  |value| is the object being stored. The value and
    510   // address registers are clobbered by the operation.
    511   void RecordWrite(
    512       Register object,
    513       Register address,
    514       Register value,
    515       RAStatus ra_status,
    516       SaveFPRegsMode save_fp,
    517       RememberedSetAction remembered_set_action = EMIT_REMEMBERED_SET,
    518       SmiCheck smi_check = INLINE_SMI_CHECK,
    519       PointersToHereCheck pointers_to_here_check_for_value =
    520           kPointersToHereMaybeInteresting);
    521 
    522 
    523   // ---------------------------------------------------------------------------
    524   // Inline caching support.
    525 
    526   void GetNumberHash(Register reg0, Register scratch);
    527 
    528   inline void MarkCode(NopMarkerTypes type) {
    529     nop(type);
    530   }
    531 
    532   // Check if the given instruction is a 'type' marker.
    533   // i.e. check if it is a sll zero_reg, zero_reg, <type> (referenced as
    534   // nop(type)). These instructions are generated to mark special location in
    535   // the code, like some special IC code.
    536   static inline bool IsMarkedCode(Instr instr, int type) {
    537     DCHECK((FIRST_IC_MARKER <= type) && (type < LAST_CODE_MARKER));
    538     return IsNop(instr, type);
    539   }
    540 
    541 
    542   static inline int GetCodeMarker(Instr instr) {
    543     uint32_t opcode = ((instr & kOpcodeMask));
    544     uint32_t rt = ((instr & kRtFieldMask) >> kRtShift);
    545     uint32_t rs = ((instr & kRsFieldMask) >> kRsShift);
    546     uint32_t sa = ((instr & kSaFieldMask) >> kSaShift);
    547 
    548     // Return <n> if we have a sll zero_reg, zero_reg, n
    549     // else return -1.
    550     bool sllzz = (opcode == SLL &&
    551                   rt == static_cast<uint32_t>(ToNumber(zero_reg)) &&
    552                   rs == static_cast<uint32_t>(ToNumber(zero_reg)));
    553     int type =
    554         (sllzz && FIRST_IC_MARKER <= sa && sa < LAST_CODE_MARKER) ? sa : -1;
    555     DCHECK((type == -1) ||
    556            ((FIRST_IC_MARKER <= type) && (type < LAST_CODE_MARKER)));
    557     return type;
    558   }
    559 
    560 
    561 
    562   // ---------------------------------------------------------------------------
    563   // Allocation support.
    564 
    565   // Allocate an object in new space or old space. The object_size is
    566   // specified either in bytes or in words if the allocation flag SIZE_IN_WORDS
    567   // is passed. If the space is exhausted control continues at the gc_required
    568   // label. The allocated object is returned in result. If the flag
    569   // tag_allocated_object is true the result is tagged as as a heap object.
    570   // All registers are clobbered also when control continues at the gc_required
    571   // label.
    572   void Allocate(int object_size,
    573                 Register result,
    574                 Register scratch1,
    575                 Register scratch2,
    576                 Label* gc_required,
    577                 AllocationFlags flags);
    578 
    579   void Allocate(Register object_size, Register result, Register result_end,
    580                 Register scratch, Label* gc_required, AllocationFlags flags);
    581 
    582   // FastAllocate is right now only used for folded allocations. It just
    583   // increments the top pointer without checking against limit. This can only
    584   // be done if it was proved earlier that the allocation will succeed.
    585   void FastAllocate(int object_size, Register result, Register scratch1,
    586                     Register scratch2, AllocationFlags flags);
    587 
    588   void FastAllocate(Register object_size, Register result, Register result_new,
    589                     Register scratch, AllocationFlags flags);
    590 
    591   // Allocates a heap number or jumps to the gc_required label if the young
    592   // space is full and a scavenge is needed. All registers are clobbered also
    593   // when control continues at the gc_required label.
    594   void AllocateHeapNumber(Register result,
    595                           Register scratch1,
    596                           Register scratch2,
    597                           Register heap_number_map,
    598                           Label* gc_required,
    599                           MutableMode mode = IMMUTABLE);
    600 
    601   void AllocateHeapNumberWithValue(Register result,
    602                                    FPURegister value,
    603                                    Register scratch1,
    604                                    Register scratch2,
    605                                    Label* gc_required);
    606 
    607   // Allocate and initialize a JSValue wrapper with the specified {constructor}
    608   // and {value}.
    609   void AllocateJSValue(Register result, Register constructor, Register value,
    610                        Register scratch1, Register scratch2,
    611                        Label* gc_required);
    612 
    613   // ---------------------------------------------------------------------------
    614   // Instruction macros.
    615 
    616 #define DEFINE_INSTRUCTION(instr)                                              \
    617   void instr(Register rd, Register rs, const Operand& rt);                     \
    618   void instr(Register rd, Register rs, Register rt) {                          \
    619     instr(rd, rs, Operand(rt));                                                \
    620   }                                                                            \
    621   void instr(Register rs, Register rt, int32_t j) {                            \
    622     instr(rs, rt, Operand(j));                                                 \
    623   }
    624 
    625 #define DEFINE_INSTRUCTION2(instr)                                             \
    626   void instr(Register rs, const Operand& rt);                                  \
    627   void instr(Register rs, Register rt) {                                       \
    628     instr(rs, Operand(rt));                                                    \
    629   }                                                                            \
    630   void instr(Register rs, int32_t j) {                                         \
    631     instr(rs, Operand(j));                                                     \
    632   }
    633 
    634   DEFINE_INSTRUCTION(Addu);
    635   DEFINE_INSTRUCTION(Daddu);
    636   DEFINE_INSTRUCTION(Div);
    637   DEFINE_INSTRUCTION(Divu);
    638   DEFINE_INSTRUCTION(Ddivu);
    639   DEFINE_INSTRUCTION(Mod);
    640   DEFINE_INSTRUCTION(Modu);
    641   DEFINE_INSTRUCTION(Ddiv);
    642   DEFINE_INSTRUCTION(Subu);
    643   DEFINE_INSTRUCTION(Dsubu);
    644   DEFINE_INSTRUCTION(Dmod);
    645   DEFINE_INSTRUCTION(Dmodu);
    646   DEFINE_INSTRUCTION(Mul);
    647   DEFINE_INSTRUCTION(Mulh);
    648   DEFINE_INSTRUCTION(Mulhu);
    649   DEFINE_INSTRUCTION(Dmul);
    650   DEFINE_INSTRUCTION(Dmulh);
    651   DEFINE_INSTRUCTION2(Mult);
    652   DEFINE_INSTRUCTION2(Dmult);
    653   DEFINE_INSTRUCTION2(Multu);
    654   DEFINE_INSTRUCTION2(Dmultu);
    655   DEFINE_INSTRUCTION2(Div);
    656   DEFINE_INSTRUCTION2(Ddiv);
    657   DEFINE_INSTRUCTION2(Divu);
    658   DEFINE_INSTRUCTION2(Ddivu);
    659 
    660   DEFINE_INSTRUCTION(And);
    661   DEFINE_INSTRUCTION(Or);
    662   DEFINE_INSTRUCTION(Xor);
    663   DEFINE_INSTRUCTION(Nor);
    664   DEFINE_INSTRUCTION2(Neg);
    665 
    666   DEFINE_INSTRUCTION(Slt);
    667   DEFINE_INSTRUCTION(Sltu);
    668 
    669   // MIPS32 R2 instruction macro.
    670   DEFINE_INSTRUCTION(Ror);
    671   DEFINE_INSTRUCTION(Dror);
    672 
    673 #undef DEFINE_INSTRUCTION
    674 #undef DEFINE_INSTRUCTION2
    675 #undef DEFINE_INSTRUCTION3
    676 
    677   // Load Scaled Address instructions. Parameter sa (shift argument) must be
    678   // between [1, 31] (inclusive). On pre-r6 architectures the scratch register
    679   // may be clobbered.
    680   void Lsa(Register rd, Register rs, Register rt, uint8_t sa,
    681            Register scratch = at);
    682   void Dlsa(Register rd, Register rs, Register rt, uint8_t sa,
    683             Register scratch = at);
    684 
    685   void Pref(int32_t hint, const MemOperand& rs);
    686 
    687 
    688   // ---------------------------------------------------------------------------
    689   // Pseudo-instructions.
    690 
    691   // Change endianness
    692   void ByteSwapSigned(Register dest, Register src, int operand_size);
    693   void ByteSwapUnsigned(Register dest, Register src, int operand_size);
    694 
    695   void mov(Register rd, Register rt) { or_(rd, rt, zero_reg); }
    696 
    697   void Ulh(Register rd, const MemOperand& rs);
    698   void Ulhu(Register rd, const MemOperand& rs);
    699   void Ush(Register rd, const MemOperand& rs, Register scratch);
    700 
    701   void Ulw(Register rd, const MemOperand& rs);
    702   void Ulwu(Register rd, const MemOperand& rs);
    703   void Usw(Register rd, const MemOperand& rs);
    704 
    705   void Uld(Register rd, const MemOperand& rs);
    706   void Usd(Register rd, const MemOperand& rs);
    707 
    708   void Ulwc1(FPURegister fd, const MemOperand& rs, Register scratch);
    709   void Uswc1(FPURegister fd, const MemOperand& rs, Register scratch);
    710 
    711   void Uldc1(FPURegister fd, const MemOperand& rs, Register scratch);
    712   void Usdc1(FPURegister fd, const MemOperand& rs, Register scratch);
    713 
    714   void LoadWordPair(Register rd, const MemOperand& rs, Register scratch = at);
    715   void StoreWordPair(Register rd, const MemOperand& rs, Register scratch = at);
    716 
    717   // Load int32 in the rd register.
    718   void li(Register rd, Operand j, LiFlags mode = OPTIMIZE_SIZE);
    719   inline bool LiLower32BitHelper(Register rd, Operand j);
    720   inline void li(Register rd, int64_t j, LiFlags mode = OPTIMIZE_SIZE) {
    721     li(rd, Operand(j), mode);
    722   }
    723   void li(Register dst, Handle<Object> value, LiFlags mode = OPTIMIZE_SIZE);
    724 
    725   // Push multiple registers on the stack.
    726   // Registers are saved in numerical order, with higher numbered registers
    727   // saved in higher memory addresses.
    728   void MultiPush(RegList regs);
    729   void MultiPushReversed(RegList regs);
    730 
    731   void MultiPushFPU(RegList regs);
    732   void MultiPushReversedFPU(RegList regs);
    733 
    734   void push(Register src) {
    735     Daddu(sp, sp, Operand(-kPointerSize));
    736     sd(src, MemOperand(sp, 0));
    737   }
    738   void Push(Register src) { push(src); }
    739 
    740   // Push a handle.
    741   void Push(Handle<Object> handle);
    742   void Push(Smi* smi) { Push(Handle<Smi>(smi, isolate())); }
    743 
    744   // Push two registers. Pushes leftmost register first (to highest address).
    745   void Push(Register src1, Register src2) {
    746     Dsubu(sp, sp, Operand(2 * kPointerSize));
    747     sd(src1, MemOperand(sp, 1 * kPointerSize));
    748     sd(src2, MemOperand(sp, 0 * kPointerSize));
    749   }
    750 
    751   // Push three registers. Pushes leftmost register first (to highest address).
    752   void Push(Register src1, Register src2, Register src3) {
    753     Dsubu(sp, sp, Operand(3 * kPointerSize));
    754     sd(src1, MemOperand(sp, 2 * kPointerSize));
    755     sd(src2, MemOperand(sp, 1 * kPointerSize));
    756     sd(src3, MemOperand(sp, 0 * kPointerSize));
    757   }
    758 
    759   // Push four registers. Pushes leftmost register first (to highest address).
    760   void Push(Register src1, Register src2, Register src3, Register src4) {
    761     Dsubu(sp, sp, Operand(4 * kPointerSize));
    762     sd(src1, MemOperand(sp, 3 * kPointerSize));
    763     sd(src2, MemOperand(sp, 2 * kPointerSize));
    764     sd(src3, MemOperand(sp, 1 * kPointerSize));
    765     sd(src4, MemOperand(sp, 0 * kPointerSize));
    766   }
    767 
    768   // Push five registers. Pushes leftmost register first (to highest address).
    769   void Push(Register src1, Register src2, Register src3, Register src4,
    770             Register src5) {
    771     Dsubu(sp, sp, Operand(5 * kPointerSize));
    772     sd(src1, MemOperand(sp, 4 * kPointerSize));
    773     sd(src2, MemOperand(sp, 3 * kPointerSize));
    774     sd(src3, MemOperand(sp, 2 * kPointerSize));
    775     sd(src4, MemOperand(sp, 1 * kPointerSize));
    776     sd(src5, MemOperand(sp, 0 * kPointerSize));
    777   }
    778 
    779   void Push(Register src, Condition cond, Register tst1, Register tst2) {
    780     // Since we don't have conditional execution we use a Branch.
    781     Branch(3, cond, tst1, Operand(tst2));
    782     Dsubu(sp, sp, Operand(kPointerSize));
    783     sd(src, MemOperand(sp, 0));
    784   }
    785 
    786   void PushRegisterAsTwoSmis(Register src, Register scratch = at);
    787   void PopRegisterAsTwoSmis(Register dst, Register scratch = at);
    788 
    789   // Pops multiple values from the stack and load them in the
    790   // registers specified in regs. Pop order is the opposite as in MultiPush.
    791   void MultiPop(RegList regs);
    792   void MultiPopReversed(RegList regs);
    793 
    794   void MultiPopFPU(RegList regs);
    795   void MultiPopReversedFPU(RegList regs);
    796 
    797   void pop(Register dst) {
    798     ld(dst, MemOperand(sp, 0));
    799     Daddu(sp, sp, Operand(kPointerSize));
    800   }
    801   void Pop(Register dst) { pop(dst); }
    802 
    803   // Pop two registers. Pops rightmost register first (from lower address).
    804   void Pop(Register src1, Register src2) {
    805     DCHECK(!src1.is(src2));
    806     ld(src2, MemOperand(sp, 0 * kPointerSize));
    807     ld(src1, MemOperand(sp, 1 * kPointerSize));
    808     Daddu(sp, sp, 2 * kPointerSize);
    809   }
    810 
    811   // Pop three registers. Pops rightmost register first (from lower address).
    812   void Pop(Register src1, Register src2, Register src3) {
    813     ld(src3, MemOperand(sp, 0 * kPointerSize));
    814     ld(src2, MemOperand(sp, 1 * kPointerSize));
    815     ld(src1, MemOperand(sp, 2 * kPointerSize));
    816     Daddu(sp, sp, 3 * kPointerSize);
    817   }
    818 
    819   void Pop(uint32_t count = 1) {
    820     Daddu(sp, sp, Operand(count * kPointerSize));
    821   }
    822 
    823   // Push a fixed frame, consisting of ra, fp.
    824   void PushCommonFrame(Register marker_reg = no_reg);
    825 
    826   // Push a standard frame, consisting of ra, fp, context and JS function.
    827   void PushStandardFrame(Register function_reg);
    828 
    829   void PopCommonFrame(Register marker_reg = no_reg);
    830 
    831   // Push and pop the registers that can hold pointers, as defined by the
    832   // RegList constant kSafepointSavedRegisters.
    833   void PushSafepointRegisters();
    834   void PopSafepointRegisters();
    835   // Store value in register src in the safepoint stack slot for
    836   // register dst.
    837   void StoreToSafepointRegisterSlot(Register src, Register dst);
    838   // Load the value of the src register from its safepoint stack slot
    839   // into register dst.
    840   void LoadFromSafepointRegisterSlot(Register dst, Register src);
    841 
    842   // MIPS64 R2 instruction macro.
    843   void Ins(Register rt, Register rs, uint16_t pos, uint16_t size);
    844   void Dins(Register rt, Register rs, uint16_t pos, uint16_t size);
    845   void Ext(Register rt, Register rs, uint16_t pos, uint16_t size);
    846 
    847   void ExtractBits(Register rt, Register rs, uint16_t pos, uint16_t size);
    848 
    849   void Dext(Register rt, Register rs, uint16_t pos, uint16_t size);
    850   void Dextm(Register rt, Register rs, uint16_t pos, uint16_t size);
    851   void Dextu(Register rt, Register rs, uint16_t pos, uint16_t size);
    852   void Neg_s(FPURegister fd, FPURegister fs);
    853   void Neg_d(FPURegister fd, FPURegister fs);
    854 
    855   // MIPS64 R6 instruction macros.
    856   void Bovc(Register rt, Register rs, Label* L);
    857   void Bnvc(Register rt, Register rs, Label* L);
    858 
    859   // ---------------------------------------------------------------------------
    860   // FPU macros. These do not handle special cases like NaN or +- inf.
    861 
    862   // Convert unsigned word to double.
    863   void Cvt_d_uw(FPURegister fd, FPURegister fs);
    864   void Cvt_d_uw(FPURegister fd, Register rs);
    865 
    866   // Convert unsigned long to double.
    867   void Cvt_d_ul(FPURegister fd, FPURegister fs);
    868   void Cvt_d_ul(FPURegister fd, Register rs);
    869 
    870   // Convert unsigned word to float.
    871   void Cvt_s_uw(FPURegister fd, FPURegister fs);
    872   void Cvt_s_uw(FPURegister fd, Register rs);
    873 
    874   // Convert unsigned long to float.
    875   void Cvt_s_ul(FPURegister fd, FPURegister fs);
    876   void Cvt_s_ul(FPURegister fd, Register rs);
    877 
    878   // Convert double to unsigned long.
    879   void Trunc_l_ud(FPURegister fd, FPURegister fs, FPURegister scratch);
    880 
    881   void Trunc_l_d(FPURegister fd, FPURegister fs);
    882   void Round_l_d(FPURegister fd, FPURegister fs);
    883   void Floor_l_d(FPURegister fd, FPURegister fs);
    884   void Ceil_l_d(FPURegister fd, FPURegister fs);
    885 
    886   // Convert double to unsigned word.
    887   void Trunc_uw_d(FPURegister fd, FPURegister fs, FPURegister scratch);
    888   void Trunc_uw_d(FPURegister fd, Register rs, FPURegister scratch);
    889 
    890   // Convert single to unsigned word.
    891   void Trunc_uw_s(FPURegister fd, FPURegister fs, FPURegister scratch);
    892   void Trunc_uw_s(FPURegister fd, Register rs, FPURegister scratch);
    893 
    894   // Convert double to unsigned long.
    895   void Trunc_ul_d(FPURegister fd, FPURegister fs, FPURegister scratch,
    896                   Register result = no_reg);
    897   void Trunc_ul_d(FPURegister fd, Register rs, FPURegister scratch,
    898                   Register result = no_reg);
    899 
    900   // Convert single to unsigned long.
    901   void Trunc_ul_s(FPURegister fd, FPURegister fs, FPURegister scratch,
    902                   Register result = no_reg);
    903   void Trunc_ul_s(FPURegister fd, Register rs, FPURegister scratch,
    904                   Register result = no_reg);
    905 
    906   void Trunc_w_d(FPURegister fd, FPURegister fs);
    907   void Round_w_d(FPURegister fd, FPURegister fs);
    908   void Floor_w_d(FPURegister fd, FPURegister fs);
    909   void Ceil_w_d(FPURegister fd, FPURegister fs);
    910 
    911   // Preserve value of a NaN operand
    912   void SubNanPreservePayloadAndSign_s(FPURegister fd, FPURegister fs,
    913                                       FPURegister ft);
    914   void SubNanPreservePayloadAndSign_d(FPURegister fd, FPURegister fs,
    915                                       FPURegister ft);
    916 
    917   void Madd_s(FPURegister fd, FPURegister fr, FPURegister fs, FPURegister ft,
    918               FPURegister scratch);
    919   void Madd_d(FPURegister fd, FPURegister fr, FPURegister fs, FPURegister ft,
    920               FPURegister scratch);
    921   void Msub_s(FPURegister fd, FPURegister fr, FPURegister fs, FPURegister ft,
    922               FPURegister scratch);
    923   void Msub_d(FPURegister fd, FPURegister fr, FPURegister fs, FPURegister ft,
    924               FPURegister scratch);
    925 
    926   // Wrapper functions for the different cmp/branch types.
    927   inline void BranchF32(Label* target, Label* nan, Condition cc,
    928                         FPURegister cmp1, FPURegister cmp2,
    929                         BranchDelaySlot bd = PROTECT) {
    930     BranchFCommon(S, target, nan, cc, cmp1, cmp2, bd);
    931   }
    932 
    933   inline void BranchF64(Label* target, Label* nan, Condition cc,
    934                         FPURegister cmp1, FPURegister cmp2,
    935                         BranchDelaySlot bd = PROTECT) {
    936     BranchFCommon(D, target, nan, cc, cmp1, cmp2, bd);
    937   }
    938 
    939   // Alternate (inline) version for better readability with USE_DELAY_SLOT.
    940   inline void BranchF64(BranchDelaySlot bd, Label* target, Label* nan,
    941                         Condition cc, FPURegister cmp1, FPURegister cmp2) {
    942     BranchF64(target, nan, cc, cmp1, cmp2, bd);
    943   }
    944 
    945   inline void BranchF32(BranchDelaySlot bd, Label* target, Label* nan,
    946                         Condition cc, FPURegister cmp1, FPURegister cmp2) {
    947     BranchF32(target, nan, cc, cmp1, cmp2, bd);
    948   }
    949 
    950   // Alias functions for backward compatibility.
    951   inline void BranchF(Label* target, Label* nan, Condition cc, FPURegister cmp1,
    952                       FPURegister cmp2, BranchDelaySlot bd = PROTECT) {
    953     BranchF64(target, nan, cc, cmp1, cmp2, bd);
    954   }
    955 
    956   inline void BranchF(BranchDelaySlot bd, Label* target, Label* nan,
    957                       Condition cc, FPURegister cmp1, FPURegister cmp2) {
    958     BranchF64(bd, target, nan, cc, cmp1, cmp2);
    959   }
    960 
    961   // Truncates a double using a specific rounding mode, and writes the value
    962   // to the result register.
    963   // The except_flag will contain any exceptions caused by the instruction.
    964   // If check_inexact is kDontCheckForInexactConversion, then the inexact
    965   // exception is masked.
    966   void EmitFPUTruncate(FPURoundingMode rounding_mode,
    967                        Register result,
    968                        DoubleRegister double_input,
    969                        Register scratch,
    970                        DoubleRegister double_scratch,
    971                        Register except_flag,
    972                        CheckForInexactConversion check_inexact
    973                            = kDontCheckForInexactConversion);
    974 
    975   // Performs a truncating conversion of a floating point number as used by
    976   // the JS bitwise operations. See ECMA-262 9.5: ToInt32. Goes to 'done' if it
    977   // succeeds, otherwise falls through if result is saturated. On return
    978   // 'result' either holds answer, or is clobbered on fall through.
    979   //
    980   // Only public for the test code in test-code-stubs-arm.cc.
    981   void TryInlineTruncateDoubleToI(Register result,
    982                                   DoubleRegister input,
    983                                   Label* done);
    984 
    985   // Performs a truncating conversion of a floating point number as used by
    986   // the JS bitwise operations. See ECMA-262 9.5: ToInt32.
    987   // Exits with 'result' holding the answer.
    988   void TruncateDoubleToI(Register result, DoubleRegister double_input);
    989 
    990   // Performs a truncating conversion of a heap number as used by
    991   // the JS bitwise operations. See ECMA-262 9.5: ToInt32. 'result' and 'input'
    992   // must be different registers. Exits with 'result' holding the answer.
    993   void TruncateHeapNumberToI(Register result, Register object);
    994 
    995   // Converts the smi or heap number in object to an int32 using the rules
    996   // for ToInt32 as described in ECMAScript 9.5.: the value is truncated
    997   // and brought into the range -2^31 .. +2^31 - 1. 'result' and 'input' must be
    998   // different registers.
    999   void TruncateNumberToI(Register object,
   1000                          Register result,
   1001                          Register heap_number_map,
   1002                          Register scratch,
   1003                          Label* not_int32);
   1004 
   1005   // Loads the number from object into dst register.
   1006   // If |object| is neither smi nor heap number, |not_number| is jumped to
   1007   // with |object| still intact.
   1008   void LoadNumber(Register object,
   1009                   FPURegister dst,
   1010                   Register heap_number_map,
   1011                   Register scratch,
   1012                   Label* not_number);
   1013 
   1014   // Loads the number from object into double_dst in the double format.
   1015   // Control will jump to not_int32 if the value cannot be exactly represented
   1016   // by a 32-bit integer.
   1017   // Floating point value in the 32-bit integer range that are not exact integer
   1018   // won't be loaded.
   1019   void LoadNumberAsInt32Double(Register object,
   1020                                DoubleRegister double_dst,
   1021                                Register heap_number_map,
   1022                                Register scratch1,
   1023                                Register scratch2,
   1024                                FPURegister double_scratch,
   1025                                Label* not_int32);
   1026 
   1027   // Loads the number from object into dst as a 32-bit integer.
   1028   // Control will jump to not_int32 if the object cannot be exactly represented
   1029   // by a 32-bit integer.
   1030   // Floating point value in the 32-bit integer range that are not exact integer
   1031   // won't be converted.
   1032   void LoadNumberAsInt32(Register object,
   1033                          Register dst,
   1034                          Register heap_number_map,
   1035                          Register scratch1,
   1036                          Register scratch2,
   1037                          FPURegister double_scratch0,
   1038                          FPURegister double_scratch1,
   1039                          Label* not_int32);
   1040 
   1041   // Enter exit frame.
   1042   // argc - argument count to be dropped by LeaveExitFrame.
   1043   // save_doubles - saves FPU registers on stack, currently disabled.
   1044   // stack_space - extra stack space.
   1045   void EnterExitFrame(bool save_doubles, int stack_space = 0,
   1046                       StackFrame::Type frame_type = StackFrame::EXIT);
   1047 
   1048   // Leave the current exit frame.
   1049   void LeaveExitFrame(bool save_doubles, Register arg_count,
   1050                       bool restore_context, bool do_return = NO_EMIT_RETURN,
   1051                       bool argument_count_is_length = false);
   1052 
   1053   // Get the actual activation frame alignment for target environment.
   1054   static int ActivationFrameAlignment();
   1055 
   1056   // Make sure the stack is aligned. Only emits code in debug mode.
   1057   void AssertStackIsAligned();
   1058 
   1059   void LoadContext(Register dst, int context_chain_length);
   1060 
   1061   // Load the global object from the current context.
   1062   void LoadGlobalObject(Register dst) {
   1063     LoadNativeContextSlot(Context::EXTENSION_INDEX, dst);
   1064   }
   1065 
   1066   // Load the global proxy from the current context.
   1067   void LoadGlobalProxy(Register dst) {
   1068     LoadNativeContextSlot(Context::GLOBAL_PROXY_INDEX, dst);
   1069   }
   1070 
   1071   void LoadNativeContextSlot(int index, Register dst);
   1072 
   1073   // Load the initial map from the global function. The registers
   1074   // function and map can be the same, function is then overwritten.
   1075   void LoadGlobalFunctionInitialMap(Register function,
   1076                                     Register map,
   1077                                     Register scratch);
   1078 
   1079   void InitializeRootRegister() {
   1080     ExternalReference roots_array_start =
   1081         ExternalReference::roots_array_start(isolate());
   1082     li(kRootRegister, Operand(roots_array_start));
   1083   }
   1084 
   1085   // -------------------------------------------------------------------------
   1086   // JavaScript invokes.
   1087 
   1088   // Removes current frame and its arguments from the stack preserving
   1089   // the arguments and a return address pushed to the stack for the next call.
   1090   // Both |callee_args_count| and |caller_args_count_reg| do not include
   1091   // receiver. |callee_args_count| is not modified, |caller_args_count_reg|
   1092   // is trashed.
   1093   void PrepareForTailCall(const ParameterCount& callee_args_count,
   1094                           Register caller_args_count_reg, Register scratch0,
   1095                           Register scratch1);
   1096 
   1097   // Invoke the JavaScript function code by either calling or jumping.
   1098   void InvokeFunctionCode(Register function, Register new_target,
   1099                           const ParameterCount& expected,
   1100                           const ParameterCount& actual, InvokeFlag flag,
   1101                           const CallWrapper& call_wrapper);
   1102 
   1103   // On function call, call into the debugger if necessary.
   1104   void CheckDebugHook(Register fun, Register new_target,
   1105                       const ParameterCount& expected,
   1106                       const ParameterCount& actual);
   1107 
   1108   // Invoke the JavaScript function in the given register. Changes the
   1109   // current context to the context in the function before invoking.
   1110   void InvokeFunction(Register function,
   1111                       Register new_target,
   1112                       const ParameterCount& actual,
   1113                       InvokeFlag flag,
   1114                       const CallWrapper& call_wrapper);
   1115 
   1116   void InvokeFunction(Register function,
   1117                       const ParameterCount& expected,
   1118                       const ParameterCount& actual,
   1119                       InvokeFlag flag,
   1120                       const CallWrapper& call_wrapper);
   1121 
   1122   void InvokeFunction(Handle<JSFunction> function,
   1123                       const ParameterCount& expected,
   1124                       const ParameterCount& actual,
   1125                       InvokeFlag flag,
   1126                       const CallWrapper& call_wrapper);
   1127 
   1128 
   1129   void IsObjectJSStringType(Register object,
   1130                             Register scratch,
   1131                             Label* fail);
   1132 
   1133   void IsObjectNameType(Register object,
   1134                         Register scratch,
   1135                         Label* fail);
   1136 
   1137   // Frame restart support.
   1138   void MaybeDropFrames();
   1139 
   1140   // Exception handling.
   1141 
   1142   // Push a new stack handler and link into stack handler chain.
   1143   void PushStackHandler();
   1144 
   1145   // Unlink the stack handler on top of the stack from the stack handler chain.
   1146   // Must preserve the result register.
   1147   void PopStackHandler();
   1148 
   1149   // Initialize fields with filler values.  Fields starting at |current_address|
   1150   // not including |end_address| are overwritten with the value in |filler|.  At
   1151   // the end the loop, |current_address| takes the value of |end_address|.
   1152   void InitializeFieldsWithFiller(Register current_address,
   1153                                   Register end_address, Register filler);
   1154 
   1155   // -------------------------------------------------------------------------
   1156   // Support functions.
   1157 
   1158   // Machine code version of Map::GetConstructor().
   1159   // |temp| holds |result|'s map when done, and |temp2| its instance type.
   1160   void GetMapConstructor(Register result, Register map, Register temp,
   1161                          Register temp2);
   1162 
   1163   void GetObjectType(Register function,
   1164                      Register map,
   1165                      Register type_reg);
   1166 
   1167   void GetInstanceType(Register object_map, Register object_instance_type) {
   1168     lbu(object_instance_type,
   1169         FieldMemOperand(object_map, Map::kInstanceTypeOffset));
   1170   }
   1171 
   1172   // Compare an object's map with the specified map and its transitioned
   1173   // elements maps if mode is ALLOW_ELEMENT_TRANSITION_MAPS. Jumps to
   1174   // "branch_to" if the result of the comparison is "cond". If multiple map
   1175   // compares are required, the compare sequences branches to early_success.
   1176   void CompareMapAndBranch(Register obj,
   1177                            Register scratch,
   1178                            Handle<Map> map,
   1179                            Label* early_success,
   1180                            Condition cond,
   1181                            Label* branch_to);
   1182 
   1183   // As above, but the map of the object is already loaded into the register
   1184   // which is preserved by the code generated.
   1185   void CompareMapAndBranch(Register obj_map,
   1186                            Handle<Map> map,
   1187                            Label* early_success,
   1188                            Condition cond,
   1189                            Label* branch_to);
   1190 
   1191   // Check if the map of an object is equal to a specified map and branch to
   1192   // label if not. Skip the smi check if not required (object is known to be a
   1193   // heap object). If mode is ALLOW_ELEMENT_TRANSITION_MAPS, then also match
   1194   // against maps that are ElementsKind transition maps of the specificed map.
   1195   void CheckMap(Register obj,
   1196                 Register scratch,
   1197                 Handle<Map> map,
   1198                 Label* fail,
   1199                 SmiCheckType smi_check_type);
   1200 
   1201 
   1202   void CheckMap(Register obj,
   1203                 Register scratch,
   1204                 Heap::RootListIndex index,
   1205                 Label* fail,
   1206                 SmiCheckType smi_check_type);
   1207 
   1208   // Check if the map of an object is equal to a specified weak map and branch
   1209   // to a specified target if equal. Skip the smi check if not required
   1210   // (object is known to be a heap object)
   1211   void DispatchWeakMap(Register obj, Register scratch1, Register scratch2,
   1212                        Handle<WeakCell> cell, Handle<Code> success,
   1213                        SmiCheckType smi_check_type);
   1214 
   1215   // If the value is a NaN, canonicalize the value else, do nothing.
   1216   void FPUCanonicalizeNaN(const DoubleRegister dst, const DoubleRegister src);
   1217 
   1218 
   1219   // Get value of the weak cell.
   1220   void GetWeakValue(Register value, Handle<WeakCell> cell);
   1221 
   1222   // Load the value of the weak cell in the value register. Branch to the
   1223   // given miss label is the weak cell was cleared.
   1224   void LoadWeakValue(Register value, Handle<WeakCell> cell, Label* miss);
   1225 
   1226   // Load and check the instance type of an object for being a string.
   1227   // Loads the type into the second argument register.
   1228   // Returns a condition that will be enabled if the object was a string.
   1229   Condition IsObjectStringType(Register obj,
   1230                                Register type,
   1231                                Register result) {
   1232     ld(type, FieldMemOperand(obj, HeapObject::kMapOffset));
   1233     lbu(type, FieldMemOperand(type, Map::kInstanceTypeOffset));
   1234     And(type, type, Operand(kIsNotStringMask));
   1235     DCHECK_EQ(0u, kStringTag);
   1236     return eq;
   1237   }
   1238 
   1239   // Get the number of least significant bits from a register.
   1240   void GetLeastBitsFromSmi(Register dst, Register src, int num_least_bits);
   1241   void GetLeastBitsFromInt32(Register dst, Register src, int mun_least_bits);
   1242 
   1243   // Load the value of a number object into a FPU double register. If the
   1244   // object is not a number a jump to the label not_number is performed
   1245   // and the FPU double register is unchanged.
   1246   void ObjectToDoubleFPURegister(
   1247       Register object,
   1248       FPURegister value,
   1249       Register scratch1,
   1250       Register scratch2,
   1251       Register heap_number_map,
   1252       Label* not_number,
   1253       ObjectToDoubleFlags flags = NO_OBJECT_TO_DOUBLE_FLAGS);
   1254 
   1255   // Load the value of a smi object into a FPU double register. The register
   1256   // scratch1 can be the same register as smi in which case smi will hold the
   1257   // untagged value afterwards.
   1258   void SmiToDoubleFPURegister(Register smi,
   1259                               FPURegister value,
   1260                               Register scratch1);
   1261 
   1262   // -------------------------------------------------------------------------
   1263   // Overflow handling functions.
   1264   // Usage: first call the appropriate arithmetic function, then call one of the
   1265   // jump functions with the overflow_dst register as the second parameter.
   1266 
   1267   inline void AddBranchOvf(Register dst, Register left, const Operand& right,
   1268                            Label* overflow_label, Register scratch = at) {
   1269     AddBranchOvf(dst, left, right, overflow_label, nullptr, scratch);
   1270   }
   1271 
   1272   inline void AddBranchNoOvf(Register dst, Register left, const Operand& right,
   1273                              Label* no_overflow_label, Register scratch = at) {
   1274     AddBranchOvf(dst, left, right, nullptr, no_overflow_label, scratch);
   1275   }
   1276 
   1277   void AddBranchOvf(Register dst, Register left, const Operand& right,
   1278                     Label* overflow_label, Label* no_overflow_label,
   1279                     Register scratch = at);
   1280 
   1281   void AddBranchOvf(Register dst, Register left, Register right,
   1282                     Label* overflow_label, Label* no_overflow_label,
   1283                     Register scratch = at);
   1284 
   1285   inline void SubBranchOvf(Register dst, Register left, const Operand& right,
   1286                            Label* overflow_label, Register scratch = at) {
   1287     SubBranchOvf(dst, left, right, overflow_label, nullptr, scratch);
   1288   }
   1289 
   1290   inline void SubBranchNoOvf(Register dst, Register left, const Operand& right,
   1291                              Label* no_overflow_label, Register scratch = at) {
   1292     SubBranchOvf(dst, left, right, nullptr, no_overflow_label, scratch);
   1293   }
   1294 
   1295   void SubBranchOvf(Register dst, Register left, const Operand& right,
   1296                     Label* overflow_label, Label* no_overflow_label,
   1297                     Register scratch = at);
   1298 
   1299   void SubBranchOvf(Register dst, Register left, Register right,
   1300                     Label* overflow_label, Label* no_overflow_label,
   1301                     Register scratch = at);
   1302 
   1303   inline void MulBranchOvf(Register dst, Register left, const Operand& right,
   1304                            Label* overflow_label, Register scratch = at) {
   1305     MulBranchOvf(dst, left, right, overflow_label, nullptr, scratch);
   1306   }
   1307 
   1308   inline void MulBranchNoOvf(Register dst, Register left, const Operand& right,
   1309                              Label* no_overflow_label, Register scratch = at) {
   1310     MulBranchOvf(dst, left, right, nullptr, no_overflow_label, scratch);
   1311   }
   1312 
   1313   void MulBranchOvf(Register dst, Register left, const Operand& right,
   1314                     Label* overflow_label, Label* no_overflow_label,
   1315                     Register scratch = at);
   1316 
   1317   void MulBranchOvf(Register dst, Register left, Register right,
   1318                     Label* overflow_label, Label* no_overflow_label,
   1319                     Register scratch = at);
   1320 
   1321   inline void DaddBranchOvf(Register dst, Register left, const Operand& right,
   1322                             Label* overflow_label, Register scratch = at) {
   1323     DaddBranchOvf(dst, left, right, overflow_label, nullptr, scratch);
   1324   }
   1325 
   1326   inline void DaddBranchNoOvf(Register dst, Register left, const Operand& right,
   1327                               Label* no_overflow_label, Register scratch = at) {
   1328     DaddBranchOvf(dst, left, right, nullptr, no_overflow_label, scratch);
   1329   }
   1330 
   1331   void DaddBranchOvf(Register dst, Register left, const Operand& right,
   1332                      Label* overflow_label, Label* no_overflow_label,
   1333                      Register scratch = at);
   1334 
   1335   void DaddBranchOvf(Register dst, Register left, Register right,
   1336                      Label* overflow_label, Label* no_overflow_label,
   1337                      Register scratch = at);
   1338 
   1339   inline void DsubBranchOvf(Register dst, Register left, const Operand& right,
   1340                             Label* overflow_label, Register scratch = at) {
   1341     DsubBranchOvf(dst, left, right, overflow_label, nullptr, scratch);
   1342   }
   1343 
   1344   inline void DsubBranchNoOvf(Register dst, Register left, const Operand& right,
   1345                               Label* no_overflow_label, Register scratch = at) {
   1346     DsubBranchOvf(dst, left, right, nullptr, no_overflow_label, scratch);
   1347   }
   1348 
   1349   void DsubBranchOvf(Register dst, Register left, const Operand& right,
   1350                      Label* overflow_label, Label* no_overflow_label,
   1351                      Register scratch = at);
   1352 
   1353   void DsubBranchOvf(Register dst, Register left, Register right,
   1354                      Label* overflow_label, Label* no_overflow_label,
   1355                      Register scratch = at);
   1356 
   1357   void BranchOnOverflow(Label* label,
   1358                         Register overflow_check,
   1359                         BranchDelaySlot bd = PROTECT) {
   1360     Branch(label, lt, overflow_check, Operand(zero_reg), bd);
   1361   }
   1362 
   1363   void BranchOnNoOverflow(Label* label,
   1364                           Register overflow_check,
   1365                           BranchDelaySlot bd = PROTECT) {
   1366     Branch(label, ge, overflow_check, Operand(zero_reg), bd);
   1367   }
   1368 
   1369   void RetOnOverflow(Register overflow_check, BranchDelaySlot bd = PROTECT) {
   1370     Ret(lt, overflow_check, Operand(zero_reg), bd);
   1371   }
   1372 
   1373   void RetOnNoOverflow(Register overflow_check, BranchDelaySlot bd = PROTECT) {
   1374     Ret(ge, overflow_check, Operand(zero_reg), bd);
   1375   }
   1376 
   1377   // Perform a floating-point min or max operation with the
   1378   // (IEEE-754-compatible) semantics of MIPS32's Release 6 MIN.fmt/MAX.fmt.
   1379   // Some cases, typically NaNs or +/-0.0, are expected to be rare and are
   1380   // handled in out-of-line code. The specific behaviour depends on supported
   1381   // instructions.
   1382   //
   1383   // These functions assume (and assert) that !src1.is(src2). It is permitted
   1384   // for the result to alias either input register.
   1385   void Float32Max(FPURegister dst, FPURegister src1, FPURegister src2,
   1386                   Label* out_of_line);
   1387   void Float32Min(FPURegister dst, FPURegister src1, FPURegister src2,
   1388                   Label* out_of_line);
   1389   void Float64Max(FPURegister dst, FPURegister src1, FPURegister src2,
   1390                   Label* out_of_line);
   1391   void Float64Min(FPURegister dst, FPURegister src1, FPURegister src2,
   1392                   Label* out_of_line);
   1393 
   1394   // Generate out-of-line cases for the macros above.
   1395   void Float32MaxOutOfLine(FPURegister dst, FPURegister src1, FPURegister src2);
   1396   void Float32MinOutOfLine(FPURegister dst, FPURegister src1, FPURegister src2);
   1397   void Float64MaxOutOfLine(FPURegister dst, FPURegister src1, FPURegister src2);
   1398   void Float64MinOutOfLine(FPURegister dst, FPURegister src1, FPURegister src2);
   1399 
   1400   // -------------------------------------------------------------------------
   1401   // Runtime calls.
   1402 
   1403   // See comments at the beginning of CEntryStub::Generate.
   1404   inline void PrepareCEntryArgs(int num_args) { li(a0, num_args); }
   1405 
   1406   inline void PrepareCEntryFunction(const ExternalReference& ref) {
   1407     li(a1, Operand(ref));
   1408   }
   1409 
   1410 #define COND_ARGS Condition cond = al, Register rs = zero_reg, \
   1411 const Operand& rt = Operand(zero_reg), BranchDelaySlot bd = PROTECT
   1412 
   1413   // Call a code stub.
   1414   void CallStub(CodeStub* stub,
   1415                 TypeFeedbackId ast_id = TypeFeedbackId::None(),
   1416                 COND_ARGS);
   1417 
   1418   // Tail call a code stub (jump).
   1419   void TailCallStub(CodeStub* stub, COND_ARGS);
   1420 
   1421 #undef COND_ARGS
   1422 
   1423   void CallJSExitStub(CodeStub* stub);
   1424 
   1425   // Call a runtime routine.
   1426   void CallRuntime(const Runtime::Function* f, int num_arguments,
   1427                    SaveFPRegsMode save_doubles = kDontSaveFPRegs,
   1428                    BranchDelaySlot bd = PROTECT);
   1429   void CallRuntimeSaveDoubles(Runtime::FunctionId fid) {
   1430     const Runtime::Function* function = Runtime::FunctionForId(fid);
   1431     CallRuntime(function, function->nargs, kSaveFPRegs);
   1432   }
   1433 
   1434   // Convenience function: Same as above, but takes the fid instead.
   1435   void CallRuntime(Runtime::FunctionId fid,
   1436                    SaveFPRegsMode save_doubles = kDontSaveFPRegs,
   1437                    BranchDelaySlot bd = PROTECT) {
   1438     const Runtime::Function* function = Runtime::FunctionForId(fid);
   1439     CallRuntime(function, function->nargs, save_doubles, bd);
   1440   }
   1441 
   1442   // Convenience function: Same as above, but takes the fid instead.
   1443   void CallRuntime(Runtime::FunctionId fid, int num_arguments,
   1444                    SaveFPRegsMode save_doubles = kDontSaveFPRegs,
   1445                    BranchDelaySlot bd = PROTECT) {
   1446     CallRuntime(Runtime::FunctionForId(fid), num_arguments, save_doubles, bd);
   1447   }
   1448 
   1449   // Convenience function: call an external reference.
   1450   void CallExternalReference(const ExternalReference& ext,
   1451                              int num_arguments,
   1452                              BranchDelaySlot bd = PROTECT);
   1453 
   1454   // Convenience function: tail call a runtime routine (jump).
   1455   void TailCallRuntime(Runtime::FunctionId fid);
   1456 
   1457   int CalculateStackPassedWords(int num_reg_arguments,
   1458                                 int num_double_arguments);
   1459 
   1460   // Before calling a C-function from generated code, align arguments on stack
   1461   // and add space for the four mips argument slots.
   1462   // After aligning the frame, non-register arguments must be stored on the
   1463   // stack, after the argument-slots using helper: CFunctionArgumentOperand().
   1464   // The argument count assumes all arguments are word sized.
   1465   // Some compilers/platforms require the stack to be aligned when calling
   1466   // C++ code.
   1467   // Needs a scratch register to do some arithmetic. This register will be
   1468   // trashed.
   1469   void PrepareCallCFunction(int num_reg_arguments,
   1470                             int num_double_registers,
   1471                             Register scratch);
   1472   void PrepareCallCFunction(int num_reg_arguments,
   1473                             Register scratch);
   1474 
   1475   // Arguments 1-4 are placed in registers a0 thru a3 respectively.
   1476   // Arguments 5..n are stored to stack using following:
   1477   //  sw(a4, CFunctionArgumentOperand(5));
   1478 
   1479   // Calls a C function and cleans up the space for arguments allocated
   1480   // by PrepareCallCFunction. The called function is not allowed to trigger a
   1481   // garbage collection, since that might move the code and invalidate the
   1482   // return address (unless this is somehow accounted for by the called
   1483   // function).
   1484   void CallCFunction(ExternalReference function, int num_arguments);
   1485   void CallCFunction(Register function, int num_arguments);
   1486   void CallCFunction(ExternalReference function,
   1487                      int num_reg_arguments,
   1488                      int num_double_arguments);
   1489   void CallCFunction(Register function,
   1490                      int num_reg_arguments,
   1491                      int num_double_arguments);
   1492   void MovFromFloatResult(DoubleRegister dst);
   1493   void MovFromFloatParameter(DoubleRegister dst);
   1494 
   1495   // There are two ways of passing double arguments on MIPS, depending on
   1496   // whether soft or hard floating point ABI is used. These functions
   1497   // abstract parameter passing for the three different ways we call
   1498   // C functions from generated code.
   1499   void MovToFloatParameter(DoubleRegister src);
   1500   void MovToFloatParameters(DoubleRegister src1, DoubleRegister src2);
   1501   void MovToFloatResult(DoubleRegister src);
   1502 
   1503   // Jump to the builtin routine.
   1504   void JumpToExternalReference(const ExternalReference& builtin,
   1505                                BranchDelaySlot bd = PROTECT,
   1506                                bool builtin_exit_frame = false);
   1507 
   1508   struct Unresolved {
   1509     int pc;
   1510     uint32_t flags;  // See Bootstrapper::FixupFlags decoders/encoders.
   1511     const char* name;
   1512   };
   1513 
   1514   Handle<Object> CodeObject() {
   1515     DCHECK(!code_object_.is_null());
   1516     return code_object_;
   1517   }
   1518 
   1519   // Emit code for a truncating division by a constant. The dividend register is
   1520   // unchanged and at gets clobbered. Dividend and result must be different.
   1521   void TruncatingDiv(Register result, Register dividend, int32_t divisor);
   1522 
   1523   // -------------------------------------------------------------------------
   1524   // StatsCounter support.
   1525 
   1526   void SetCounter(StatsCounter* counter, int value,
   1527                   Register scratch1, Register scratch2);
   1528   void IncrementCounter(StatsCounter* counter, int value,
   1529                         Register scratch1, Register scratch2);
   1530   void DecrementCounter(StatsCounter* counter, int value,
   1531                         Register scratch1, Register scratch2);
   1532 
   1533 
   1534   // -------------------------------------------------------------------------
   1535   // Debugging.
   1536 
   1537   // Calls Abort(msg) if the condition cc is not satisfied.
   1538   // Use --debug_code to enable.
   1539   void Assert(Condition cc, BailoutReason reason, Register rs, Operand rt);
   1540   void AssertFastElements(Register elements);
   1541 
   1542   // Like Assert(), but always enabled.
   1543   void Check(Condition cc, BailoutReason reason, Register rs, Operand rt);
   1544 
   1545   // Print a message to stdout and abort execution.
   1546   void Abort(BailoutReason msg);
   1547 
   1548   // Verify restrictions about code generated in stubs.
   1549   void set_generating_stub(bool value) { generating_stub_ = value; }
   1550   bool generating_stub() { return generating_stub_; }
   1551   void set_has_frame(bool value) { has_frame_ = value; }
   1552   bool has_frame() { return has_frame_; }
   1553   inline bool AllowThisStubCall(CodeStub* stub);
   1554 
   1555   // ---------------------------------------------------------------------------
   1556   // Number utilities.
   1557 
   1558   // Check whether the value of reg is a power of two and not zero. If not
   1559   // control continues at the label not_power_of_two. If reg is a power of two
   1560   // the register scratch contains the value of (reg - 1) when control falls
   1561   // through.
   1562   void JumpIfNotPowerOfTwoOrZero(Register reg,
   1563                                  Register scratch,
   1564                                  Label* not_power_of_two_or_zero);
   1565 
   1566   // -------------------------------------------------------------------------
   1567   // Smi utilities.
   1568 
   1569   // Test for overflow < 0: use BranchOnOverflow() or BranchOnNoOverflow().
   1570   void SmiTagCheckOverflow(Register reg, Register overflow);
   1571   void SmiTagCheckOverflow(Register dst, Register src, Register overflow);
   1572 
   1573   void SmiTag(Register dst, Register src) {
   1574     STATIC_ASSERT(kSmiTag == 0);
   1575     if (SmiValuesAre32Bits()) {
   1576       STATIC_ASSERT(kSmiShift == 32);
   1577       dsll32(dst, src, 0);
   1578     } else {
   1579       Addu(dst, src, src);
   1580     }
   1581   }
   1582 
   1583   void SmiTag(Register reg) {
   1584     SmiTag(reg, reg);
   1585   }
   1586 
   1587   // Try to convert int32 to smi. If the value is to large, preserve
   1588   // the original value and jump to not_a_smi. Destroys scratch and
   1589   // sets flags.
   1590   void TrySmiTag(Register reg, Register scratch, Label* not_a_smi) {
   1591     TrySmiTag(reg, reg, scratch, not_a_smi);
   1592   }
   1593 
   1594   void TrySmiTag(Register dst,
   1595                  Register src,
   1596                  Register scratch,
   1597                  Label* not_a_smi) {
   1598     if (SmiValuesAre32Bits()) {
   1599       SmiTag(dst, src);
   1600     } else {
   1601       SmiTagCheckOverflow(at, src, scratch);
   1602       BranchOnOverflow(not_a_smi, scratch);
   1603       mov(dst, at);
   1604     }
   1605   }
   1606 
   1607   void SmiUntag(Register dst, Register src) {
   1608     if (SmiValuesAre32Bits()) {
   1609       STATIC_ASSERT(kSmiShift == 32);
   1610       dsra32(dst, src, 0);
   1611     } else {
   1612       sra(dst, src, kSmiTagSize);
   1613     }
   1614   }
   1615 
   1616   void SmiUntag(Register reg) {
   1617     SmiUntag(reg, reg);
   1618   }
   1619 
   1620   // Left-shifted from int32 equivalent of Smi.
   1621   void SmiScale(Register dst, Register src, int scale) {
   1622     if (SmiValuesAre32Bits()) {
   1623       // The int portion is upper 32-bits of 64-bit word.
   1624       dsra(dst, src, kSmiShift - scale);
   1625     } else {
   1626       DCHECK(scale >= kSmiTagSize);
   1627       sll(dst, src, scale - kSmiTagSize);
   1628     }
   1629   }
   1630 
   1631   // Combine load with untagging or scaling.
   1632   void SmiLoadUntag(Register dst, MemOperand src);
   1633 
   1634   void SmiLoadScale(Register dst, MemOperand src, int scale);
   1635 
   1636   // Returns 2 values: the Smi and a scaled version of the int within the Smi.
   1637   void SmiLoadWithScale(Register d_smi,
   1638                         Register d_scaled,
   1639                         MemOperand src,
   1640                         int scale);
   1641 
   1642   // Returns 2 values: the untagged Smi (int32) and scaled version of that int.
   1643   void SmiLoadUntagWithScale(Register d_int,
   1644                              Register d_scaled,
   1645                              MemOperand src,
   1646                              int scale);
   1647 
   1648 
   1649   // Test if the register contains a smi.
   1650   inline void SmiTst(Register value, Register scratch) {
   1651     And(scratch, value, Operand(kSmiTagMask));
   1652   }
   1653   inline void NonNegativeSmiTst(Register value, Register scratch) {
   1654     And(scratch, value, Operand(kSmiTagMask | kSmiSignMask));
   1655   }
   1656 
   1657   // Untag the source value into destination and jump if source is a smi.
   1658   // Source and destination can be the same register.
   1659   void UntagAndJumpIfSmi(Register dst, Register src, Label* smi_case);
   1660 
   1661   // Jump the register contains a smi.
   1662   void JumpIfSmi(Register value,
   1663                  Label* smi_label,
   1664                  Register scratch = at,
   1665                  BranchDelaySlot bd = PROTECT);
   1666 
   1667   // Jump if the register contains a non-smi.
   1668   void JumpIfNotSmi(Register value,
   1669                     Label* not_smi_label,
   1670                     Register scratch = at,
   1671                     BranchDelaySlot bd = PROTECT);
   1672 
   1673   // Jump if either of the registers contain a non-smi.
   1674   void JumpIfNotBothSmi(Register reg1, Register reg2, Label* on_not_both_smi);
   1675   // Jump if either of the registers contain a smi.
   1676   void JumpIfEitherSmi(Register reg1, Register reg2, Label* on_either_smi);
   1677 
   1678   // Abort execution if argument is a number, enabled via --debug-code.
   1679   void AssertNotNumber(Register object);
   1680 
   1681   // Abort execution if argument is a smi, enabled via --debug-code.
   1682   void AssertNotSmi(Register object);
   1683   void AssertSmi(Register object);
   1684 
   1685   // Abort execution if argument is not a string, enabled via --debug-code.
   1686   void AssertString(Register object);
   1687 
   1688   // Abort execution if argument is not a name, enabled via --debug-code.
   1689   void AssertName(Register object);
   1690 
   1691   // Abort execution if argument is not a JSFunction, enabled via --debug-code.
   1692   void AssertFunction(Register object);
   1693 
   1694   // Abort execution if argument is not a JSBoundFunction,
   1695   // enabled via --debug-code.
   1696   void AssertBoundFunction(Register object);
   1697 
   1698   // Abort execution if argument is not a JSGeneratorObject,
   1699   // enabled via --debug-code.
   1700   void AssertGeneratorObject(Register object);
   1701 
   1702   // Abort execution if argument is not a JSReceiver, enabled via --debug-code.
   1703   void AssertReceiver(Register object);
   1704 
   1705   // Abort execution if argument is not undefined or an AllocationSite, enabled
   1706   // via --debug-code.
   1707   void AssertUndefinedOrAllocationSite(Register object, Register scratch);
   1708 
   1709   // Abort execution if reg is not the root value with the given index,
   1710   // enabled via --debug-code.
   1711   void AssertIsRoot(Register reg, Heap::RootListIndex index);
   1712 
   1713   // ---------------------------------------------------------------------------
   1714   // HeapNumber utilities.
   1715 
   1716   void JumpIfNotHeapNumber(Register object,
   1717                            Register heap_number_map,
   1718                            Register scratch,
   1719                            Label* on_not_heap_number);
   1720 
   1721   // -------------------------------------------------------------------------
   1722   // String utilities.
   1723 
   1724   // Checks if both instance types are sequential one-byte strings and jumps to
   1725   // label if either is not.
   1726   void JumpIfBothInstanceTypesAreNotSequentialOneByte(
   1727       Register first_object_instance_type, Register second_object_instance_type,
   1728       Register scratch1, Register scratch2, Label* failure);
   1729 
   1730   void JumpIfNotUniqueNameInstanceType(Register reg, Label* not_unique_name);
   1731 
   1732   void EmitSeqStringSetCharCheck(Register string,
   1733                                  Register index,
   1734                                  Register value,
   1735                                  Register scratch,
   1736                                  uint32_t encoding_mask);
   1737 
   1738   // Checks if both objects are sequential one-byte strings and jumps to label
   1739   // if either is not. Assumes that neither object is a smi.
   1740   void JumpIfNonSmisNotBothSequentialOneByteStrings(Register first,
   1741                                                     Register second,
   1742                                                     Register scratch1,
   1743                                                     Register scratch2,
   1744                                                     Label* failure);
   1745 
   1746   // Checks if both objects are sequential one-byte strings and jumps to label
   1747   // if either is not.
   1748   void JumpIfNotBothSequentialOneByteStrings(Register first, Register second,
   1749                                              Register scratch1,
   1750                                              Register scratch2,
   1751                                              Label* not_flat_one_byte_strings);
   1752 
   1753   void ClampUint8(Register output_reg, Register input_reg);
   1754 
   1755   void ClampDoubleToUint8(Register result_reg,
   1756                           DoubleRegister input_reg,
   1757                           DoubleRegister temp_double_reg);
   1758 
   1759 
   1760   void LoadInstanceDescriptors(Register map, Register descriptors);
   1761   void EnumLength(Register dst, Register map);
   1762   void NumberOfOwnDescriptors(Register dst, Register map);
   1763   void LoadAccessor(Register dst, Register holder, int accessor_index,
   1764                     AccessorComponent accessor);
   1765 
   1766   template<typename Field>
   1767   void DecodeField(Register dst, Register src) {
   1768     Ext(dst, src, Field::kShift, Field::kSize);
   1769   }
   1770 
   1771   template<typename Field>
   1772   void DecodeField(Register reg) {
   1773     DecodeField<Field>(reg, reg);
   1774   }
   1775 
   1776   template<typename Field>
   1777   void DecodeFieldToSmi(Register dst, Register src) {
   1778     static const int shift = Field::kShift;
   1779     static const int mask = Field::kMask >> shift;
   1780     dsrl(dst, src, shift);
   1781     And(dst, dst, Operand(mask));
   1782     dsll32(dst, dst, 0);
   1783   }
   1784 
   1785   template<typename Field>
   1786   void DecodeFieldToSmi(Register reg) {
   1787     DecodeField<Field>(reg, reg);
   1788   }
   1789   // Generates function and stub prologue code.
   1790   void StubPrologue(StackFrame::Type type);
   1791   void Prologue(bool code_pre_aging);
   1792 
   1793   // Load the type feedback vector from a JavaScript frame.
   1794   void EmitLoadFeedbackVector(Register vector);
   1795 
   1796   // Activation support.
   1797   void EnterFrame(StackFrame::Type type);
   1798   void EnterFrame(StackFrame::Type type, bool load_constant_pool_pointer_reg);
   1799   void LeaveFrame(StackFrame::Type type);
   1800 
   1801   void EnterBuiltinFrame(Register context, Register target, Register argc);
   1802   void LeaveBuiltinFrame(Register context, Register target, Register argc);
   1803 
   1804   // Expects object in a0 and returns map with validated enum cache
   1805   // in a0.  Assumes that any other register can be used as a scratch.
   1806   void CheckEnumCache(Label* call_runtime);
   1807 
   1808   // AllocationMemento support. Arrays may have an associated AllocationMemento
   1809   // object that can be checked for in order to pretransition to another type.
   1810   // On entry, receiver_reg should point to the array object. scratch_reg gets
   1811   // clobbered. If no info is present jump to no_memento_found, otherwise fall
   1812   // through.
   1813   void TestJSArrayForAllocationMemento(Register receiver_reg,
   1814                                        Register scratch_reg,
   1815                                        Label* no_memento_found);
   1816 
   1817   bool IsDoubleZeroRegSet() { return has_double_zero_reg_set_; }
   1818 
   1819  private:
   1820   void CallCFunctionHelper(Register function,
   1821                            int num_reg_arguments,
   1822                            int num_double_arguments);
   1823 
   1824   inline Register GetRtAsRegisterHelper(const Operand& rt, Register scratch);
   1825   inline int32_t GetOffset(int32_t offset, Label* L, OffsetSize bits);
   1826   void BranchShortHelperR6(int32_t offset, Label* L);
   1827   void BranchShortHelper(int16_t offset, Label* L, BranchDelaySlot bdslot);
   1828   bool BranchShortHelperR6(int32_t offset, Label* L, Condition cond,
   1829                            Register rs, const Operand& rt);
   1830   bool BranchShortHelper(int16_t offset, Label* L, Condition cond, Register rs,
   1831                          const Operand& rt, BranchDelaySlot bdslot);
   1832   bool BranchShortCheck(int32_t offset, Label* L, Condition cond, Register rs,
   1833                         const Operand& rt, BranchDelaySlot bdslot);
   1834 
   1835   void BranchAndLinkShortHelperR6(int32_t offset, Label* L);
   1836   void BranchAndLinkShortHelper(int16_t offset, Label* L,
   1837                                 BranchDelaySlot bdslot);
   1838   void BranchAndLinkShort(int32_t offset, BranchDelaySlot bdslot = PROTECT);
   1839   void BranchAndLinkShort(Label* L, BranchDelaySlot bdslot = PROTECT);
   1840   bool BranchAndLinkShortHelperR6(int32_t offset, Label* L, Condition cond,
   1841                                   Register rs, const Operand& rt);
   1842   bool BranchAndLinkShortHelper(int16_t offset, Label* L, Condition cond,
   1843                                 Register rs, const Operand& rt,
   1844                                 BranchDelaySlot bdslot);
   1845   bool BranchAndLinkShortCheck(int32_t offset, Label* L, Condition cond,
   1846                                Register rs, const Operand& rt,
   1847                                BranchDelaySlot bdslot);
   1848   void BranchLong(Label* L, BranchDelaySlot bdslot);
   1849   void BranchAndLinkLong(Label* L, BranchDelaySlot bdslot);
   1850 
   1851   // Common implementation of BranchF functions for the different formats.
   1852   void BranchFCommon(SecondaryField sizeField, Label* target, Label* nan,
   1853                      Condition cc, FPURegister cmp1, FPURegister cmp2,
   1854                      BranchDelaySlot bd = PROTECT);
   1855 
   1856   void BranchShortF(SecondaryField sizeField, Label* target, Condition cc,
   1857                     FPURegister cmp1, FPURegister cmp2,
   1858                     BranchDelaySlot bd = PROTECT);
   1859 
   1860 
   1861   // Helper functions for generating invokes.
   1862   void InvokePrologue(const ParameterCount& expected,
   1863                       const ParameterCount& actual,
   1864                       Label* done,
   1865                       bool* definitely_mismatches,
   1866                       InvokeFlag flag,
   1867                       const CallWrapper& call_wrapper);
   1868 
   1869   // Helper for implementing JumpIfNotInNewSpace and JumpIfInNewSpace.
   1870   void InNewSpace(Register object, Register scratch,
   1871                   Condition cond,  // ne for new space, eq otherwise.
   1872                   Label* branch);
   1873 
   1874   // Helper for finding the mark bits for an address.  Afterwards, the
   1875   // bitmap register points at the word with the mark bits and the mask
   1876   // the position of the first bit.  Leaves addr_reg unchanged.
   1877   inline void GetMarkBits(Register addr_reg,
   1878                           Register bitmap_reg,
   1879                           Register mask_reg);
   1880 
   1881   // Compute memory operands for safepoint stack slots.
   1882   static int SafepointRegisterStackIndex(int reg_code);
   1883   MemOperand SafepointRegisterSlot(Register reg);
   1884   MemOperand SafepointRegistersAndDoublesSlot(Register reg);
   1885 
   1886   bool generating_stub_;
   1887   bool has_frame_;
   1888   bool has_double_zero_reg_set_;
   1889   // This handle will be patched with the code object on installation.
   1890   Handle<Object> code_object_;
   1891 
   1892   // Needs access to SafepointRegisterStackIndex for compiled frame
   1893   // traversal.
   1894   friend class StandardFrame;
   1895 };
   1896 
   1897 
   1898 // The code patcher is used to patch (typically) small parts of code e.g. for
   1899 // debugging and other types of instrumentation. When using the code patcher
   1900 // the exact number of bytes specified must be emitted. It is not legal to emit
   1901 // relocation information. If any of these constraints are violated it causes
   1902 // an assertion to fail.
   1903 class CodePatcher {
   1904  public:
   1905   enum FlushICache {
   1906     FLUSH,
   1907     DONT_FLUSH
   1908   };
   1909 
   1910   CodePatcher(Isolate* isolate, byte* address, int instructions,
   1911               FlushICache flush_cache = FLUSH);
   1912   ~CodePatcher();
   1913 
   1914   // Macro assembler to emit code.
   1915   MacroAssembler* masm() { return &masm_; }
   1916 
   1917   // Emit an instruction directly.
   1918   void Emit(Instr instr);
   1919 
   1920   // Emit an address directly.
   1921   void Emit(Address addr);
   1922 
   1923   // Change the condition part of an instruction leaving the rest of the current
   1924   // instruction unchanged.
   1925   void ChangeBranchCondition(Instr current_instr, uint32_t new_opcode);
   1926 
   1927  private:
   1928   byte* address_;  // The address of the code being patched.
   1929   int size_;  // Number of bytes of the expected patch size.
   1930   MacroAssembler masm_;  // Macro assembler used to generate the code.
   1931   FlushICache flush_cache_;  // Whether to flush the I cache after patching.
   1932 };
   1933 
   1934 template <typename Func>
   1935 void MacroAssembler::GenerateSwitchTable(Register index, size_t case_count,
   1936                                          Func GetLabelFunction) {
   1937   // Ensure that dd-ed labels following this instruction use 8 bytes aligned
   1938   // addresses.
   1939   if (kArchVariant >= kMips64r6) {
   1940     BlockTrampolinePoolFor(static_cast<int>(case_count) * 2 +
   1941                            kSwitchTablePrologueSize);
   1942     // Opposite of Align(8) as we have odd number of instructions in this case.
   1943     if ((pc_offset() & 7) == 0) {
   1944       nop();
   1945     }
   1946     addiupc(at, 5);
   1947     Dlsa(at, at, index, kPointerSizeLog2);
   1948     ld(at, MemOperand(at));
   1949   } else {
   1950     Label here;
   1951     BlockTrampolinePoolFor(static_cast<int>(case_count) * 2 +
   1952                            kSwitchTablePrologueSize);
   1953     Align(8);
   1954     push(ra);
   1955     bal(&here);
   1956     dsll(at, index, kPointerSizeLog2);  // Branch delay slot.
   1957     bind(&here);
   1958     daddu(at, at, ra);
   1959     pop(ra);
   1960     ld(at, MemOperand(at, 6 * v8::internal::Assembler::kInstrSize));
   1961   }
   1962   jr(at);
   1963   nop();  // Branch delay slot nop.
   1964   for (size_t index = 0; index < case_count; ++index) {
   1965     dd(GetLabelFunction(index));
   1966   }
   1967 }
   1968 
   1969 #define ACCESS_MASM(masm) masm->
   1970 
   1971 }  // namespace internal
   1972 }  // namespace v8
   1973 
   1974 #endif  // V8_MIPS_MACRO_ASSEMBLER_MIPS_H_
   1975