text: // Copyright 2011 the V8 project authors. All rights reserved.
  // Redistribution and use in source and binary forms, with or without
  // modification, are permitted provided that the following conditions are
  // met:
  //
  //     * Redistributions of source code must retain the above copyright
  //       notice, this list of conditions and the following disclaimer.
  //     * Redistributions in binary form must reproduce the above
  //       copyright notice, this list of conditions and the following
  //       disclaimer in the documentation and/or other materials provided
  //       with the distribution.
  //     * Neither the name of Google Inc. nor the names of its
  //       contributors may be used to endorse or promote products derived
  //       from this software without specific prior written permission.
  //
  // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  
  #ifndef V8_MIPS_CODE_STUBS_ARM_H_
  #define V8_MIPS_CODE_STUBS_ARM_H_
  
  #include "ic-inl.h"
  
  
  namespace v8 {
  namespace internal {
  
  
  // Compute a transcendental math function natively, or call the
  // TranscendentalCache runtime function.
  class TranscendentalCacheStub: public PlatformCodeStub {
   public:
    enum ArgumentType {
      TAGGED = 0 << TranscendentalCache::kTranscendentalTypeBits,
      UNTAGGED = 1 << TranscendentalCache::kTranscendentalTypeBits
    };
  
    TranscendentalCacheStub(TranscendentalCache::Type type,
                            ArgumentType argument_type)
        : type_(type), argument_type_(argument_type) { }
    void Generate(MacroAssembler* masm);
   private:
    TranscendentalCache::Type type_;
    ArgumentType argument_type_;
    void GenerateCallCFunction(MacroAssembler* masm, Register scratch);
  
    Major MajorKey() { return TranscendentalCache; }
    int MinorKey() { return type_ | argument_type_; }
    Runtime::FunctionId RuntimeFunction();
  };
  
  
  class StoreBufferOverflowStub: public PlatformCodeStub {
   public:
    explicit StoreBufferOverflowStub(SaveFPRegsMode save_fp)
        : save_doubles_(save_fp) { }
  
    void Generate(MacroAssembler* masm);
  
    virtual bool IsPregenerated();
    static void GenerateFixedRegStubsAheadOfTime();
    virtual bool SometimesSetsUpAFrame() { return false; }
  
   private:
    SaveFPRegsMode save_doubles_;
  
    Major MajorKey() { return StoreBufferOverflow; }
    int MinorKey() { return (save_doubles_ == kSaveFPRegs) ? 1 : 0; }
  };
  
  
  class UnaryOpStub: public PlatformCodeStub {
   public:
    UnaryOpStub(Token::Value op,
                UnaryOverwriteMode mode,
                UnaryOpIC::TypeInfo operand_type = UnaryOpIC::UNINITIALIZED)
        : op_(op),
          mode_(mode),
          operand_type_(operand_type) {
    }
  
   private:
    Token::Value op_;
    UnaryOverwriteMode mode_;
  
    // Operand type information determined at runtime.
    UnaryOpIC::TypeInfo operand_type_;
  
    virtual void PrintName(StringStream* stream);
  
    class ModeBits: public BitField<UnaryOverwriteMode, 0, 1> {};
    class OpBits: public BitField<Token::Value, 1, 7> {};
    class OperandTypeInfoBits: public BitField<UnaryOpIC::TypeInfo, 8, 3> {};
  
    Major MajorKey() { return UnaryOp; }
    int MinorKey() {
      return ModeBits::encode(mode_)
             | OpBits::encode(op_)
             | OperandTypeInfoBits::encode(operand_type_);
    }
  
    // Note: A lot of the helper functions below will vanish when we use virtual
    // function instead of switch more often.
    void Generate(MacroAssembler* masm);
  
    void GenerateTypeTransition(MacroAssembler* masm);
  
    void GenerateSmiStub(MacroAssembler* masm);
    void GenerateSmiStubSub(MacroAssembler* masm);
    void GenerateSmiStubBitNot(MacroAssembler* masm);
    void GenerateSmiCodeSub(MacroAssembler* masm, Label* non_smi, Label* slow);
    void GenerateSmiCodeBitNot(MacroAssembler* masm, Label* slow);
  
    void GenerateHeapNumberStub(MacroAssembler* masm);
    void GenerateHeapNumberStubSub(MacroAssembler* masm);
    void GenerateHeapNumberStubBitNot(MacroAssembler* masm);
    void GenerateHeapNumberCodeSub(MacroAssembler* masm, Label* slow);
    void GenerateHeapNumberCodeBitNot(MacroAssembler* masm, Label* slow);
  
    void GenerateGenericStub(MacroAssembler* masm);
    void GenerateGenericStubSub(MacroAssembler* masm);
    void GenerateGenericStubBitNot(MacroAssembler* masm);
    void GenerateGenericCodeFallback(MacroAssembler* masm);
  
    virtual int GetCodeKind() { return Code::UNARY_OP_IC; }
  
    virtual InlineCacheState GetICState() {
      return UnaryOpIC::ToState(operand_type_);
    }
  
    virtual void FinishCode(Handle<Code> code) {
      code->set_unary_op_type(operand_type_);
    }
  };
  
  
  class StringHelper : public AllStatic {
   public:
    // Generate code for copying characters using a simple loop. This should only
    // be used in places where the number of characters is small and the
    // additional setup and checking in GenerateCopyCharactersLong adds too much
    // overhead. Copying of overlapping regions is not supported.
    // Dest register ends at the position after the last character written.
    static void GenerateCopyCharacters(MacroAssembler* masm,
                                       Register dest,
                                       Register src,
                                       Register count,
                                       Register scratch,
                                       bool ascii);
  
    // Generate code for copying a large number of characters. This function
    // is allowed to spend extra time setting up conditions to make copying
    // faster. Copying of overlapping regions is not supported.
    // Dest register ends at the position after the last character written.
    static void GenerateCopyCharactersLong(MacroAssembler* masm,
                                           Register dest,
                                           Register src,
                                           Register count,
                                           Register scratch1,
                                           Register scratch2,
                                           Register scratch3,
                                           Register scratch4,
                                           Register scratch5,
                                           int flags);
  
  
    // Probe the symbol table for a two character string. If the string is
    // not found by probing a jump to the label not_found is performed. This jump
    // does not guarantee that the string is not in the symbol table. If the
    // string is found the code falls through with the string in register r0.
    // Contents of both c1 and c2 registers are modified. At the exit c1 is
    // guaranteed to contain halfword with low and high bytes equal to
    // initial contents of c1 and c2 respectively.
    static void GenerateTwoCharacterSymbolTableProbe(MacroAssembler* masm,
                                                     Register c1,
                                                     Register c2,
                                                     Register scratch1,
                                                     Register scratch2,
                                                     Register scratch3,
                                                     Register scratch4,
                                                     Register scratch5,
                                                     Label* not_found);
  
    // Generate string hash.
    static void GenerateHashInit(MacroAssembler* masm,
                                 Register hash,
                                 Register character);
  
    static void GenerateHashAddCharacter(MacroAssembler* masm,
                                         Register hash,
                                         Register character);
  
    static void GenerateHashGetHash(MacroAssembler* masm,
                                    Register hash);
  
   private:
    DISALLOW_IMPLICIT_CONSTRUCTORS(StringHelper);
  };
  
  
  // Flag that indicates how to generate code for the stub StringAddStub.
  enum StringAddFlags {
    NO_STRING_ADD_FLAGS = 0,
    // Omit left string check in stub (left is definitely a string).
    NO_STRING_CHECK_LEFT_IN_STUB = 1 << 0,
    // Omit right string check in stub (right is definitely a string).
    NO_STRING_CHECK_RIGHT_IN_STUB = 1 << 1,
    // Omit both string checks in stub.
    NO_STRING_CHECK_IN_STUB =
        NO_STRING_CHECK_LEFT_IN_STUB | NO_STRING_CHECK_RIGHT_IN_STUB
  };
  
  
  class StringAddStub: public PlatformCodeStub {
   public:
    explicit StringAddStub(StringAddFlags flags) : flags_(flags) {}
  
   private:
    Major MajorKey() { return StringAdd; }
    int MinorKey() { return flags_; }
  
    void Generate(MacroAssembler* masm);
  
    void GenerateConvertArgument(MacroAssembler* masm,
                                 int stack_offset,
                                 Register arg,
                                 Register scratch1,
                                 Register scratch2,
                                 Register scratch3,
                                 Register scratch4,
                                 Label* slow);
  
    const StringAddFlags flags_;
  };
  
  
  class SubStringStub: public PlatformCodeStub {
   public:
    SubStringStub() {}
  
   private:
    Major MajorKey() { return SubString; }
    int MinorKey() { return 0; }
  
    void Generate(MacroAssembler* masm);
  };
  
  
  class StringCompareStub: public PlatformCodeStub {
   public:
    StringCompareStub() { }
  
    // Compare two flat ASCII strings and returns result in v0.
    static void GenerateCompareFlatAsciiStrings(MacroAssembler* masm,
                                                Register left,
                                                Register right,
                                                Register scratch1,
                                                Register scratch2,
                                                Register scratch3,
                                                Register scratch4);
  
    // Compares two flat ASCII strings for equality and returns result
    // in v0.
    static void GenerateFlatAsciiStringEquals(MacroAssembler* masm,
                                              Register left,
                                              Register right,
                                              Register scratch1,
                                              Register scratch2,
                                              Register scratch3);
  
   private:
    virtual Major MajorKey() { return StringCompare; }
    virtual int MinorKey() { return 0; }
    virtual void Generate(MacroAssembler* masm);
  
    static void GenerateAsciiCharsCompareLoop(MacroAssembler* masm,
                                              Register left,
                                              Register right,
                                              Register length,
                                              Register scratch1,
                                              Register scratch2,
                                              Register scratch3,
                                              Label* chars_not_equal);
  };
  
  
  // This stub can convert a signed int32 to a heap number (double).  It does
  // not work for int32s that are in Smi range!  No GC occurs during this stub
  // so you don't have to set up the frame.
  class WriteInt32ToHeapNumberStub : public PlatformCodeStub {
   public:
    WriteInt32ToHeapNumberStub(Register the_int,
                               Register the_heap_number,
                               Register scratch,
                               Register scratch2)
        : the_int_(the_int),
          the_heap_number_(the_heap_number),
          scratch_(scratch),
          sign_(scratch2) {
      ASSERT(IntRegisterBits::is_valid(the_int_.code()));
      ASSERT(HeapNumberRegisterBits::is_valid(the_heap_number_.code()));
      ASSERT(ScratchRegisterBits::is_valid(scratch_.code()));
      ASSERT(SignRegisterBits::is_valid(sign_.code()));
    }
  
    bool IsPregenerated();
    static void GenerateFixedRegStubsAheadOfTime();
  
   private:
    Register the_int_;
    Register the_heap_number_;
    Register scratch_;
    Register sign_;
  
    // Minor key encoding in 16 bits.
    class IntRegisterBits: public BitField<int, 0, 4> {};
    class HeapNumberRegisterBits: public BitField<int, 4, 4> {};
    class ScratchRegisterBits: public BitField<int, 8, 4> {};
    class SignRegisterBits: public BitField<int, 12, 4> {};
  
    Major MajorKey() { return WriteInt32ToHeapNumber; }
    int MinorKey() {
      // Encode the parameters in a unique 16 bit value.
      return IntRegisterBits::encode(the_int_.code())
             | HeapNumberRegisterBits::encode(the_heap_number_.code())
             | ScratchRegisterBits::encode(scratch_.code())
             | SignRegisterBits::encode(sign_.code());
    }
  
    void Generate(MacroAssembler* masm);
  };
  
  
  class NumberToStringStub: public PlatformCodeStub {
   public:
    NumberToStringStub() { }
  
    // Generate code to do a lookup in the number string cache. If the number in
    // the register object is found in the cache the generated code falls through
    // with the result in the result register. The object and the result register
    // can be the same. If the number is not found in the cache the code jumps to
    // the label not_found with only the content of register object unchanged.
    static void GenerateLookupNumberStringCache(MacroAssembler* masm,
                                                Register object,
                                                Register result,
                                                Register scratch1,
                                                Register scratch2,
                                                Register scratch3,
                                                bool object_is_smi,
                                                Label* not_found);
  
   private:
    Major MajorKey() { return NumberToString; }
    int MinorKey() { return 0; }
  
    void Generate(MacroAssembler* masm);
  };
  
  
  class RecordWriteStub: public PlatformCodeStub {
   public:
    RecordWriteStub(Register object,
                    Register value,
                    Register address,
                    RememberedSetAction remembered_set_action,
                    SaveFPRegsMode fp_mode)
        : object_(object),
          value_(value),
          address_(address),
          remembered_set_action_(remembered_set_action),
          save_fp_regs_mode_(fp_mode),
          regs_(object,   // An input reg.
                address,  // An input reg.
                value) {  // One scratch reg.
    }
  
    enum Mode {
      STORE_BUFFER_ONLY,
      INCREMENTAL,
      INCREMENTAL_COMPACTION
    };
  
    virtual bool IsPregenerated();
    static void GenerateFixedRegStubsAheadOfTime();
    virtual bool SometimesSetsUpAFrame() { return false; }
  
    static void PatchBranchIntoNop(MacroAssembler* masm, int pos) {
      const unsigned offset = masm->instr_at(pos) & kImm16Mask;
      masm->instr_at_put(pos, BNE | (zero_reg.code() << kRsShift) |
          (zero_reg.code() << kRtShift) | (offset & kImm16Mask));
      ASSERT(Assembler::IsBne(masm->instr_at(pos)));
    }
  
    static void PatchNopIntoBranch(MacroAssembler* masm, int pos) {
      const unsigned offset = masm->instr_at(pos) & kImm16Mask;
      masm->instr_at_put(pos, BEQ | (zero_reg.code() << kRsShift) |
          (zero_reg.code() << kRtShift) | (offset & kImm16Mask));
      ASSERT(Assembler::IsBeq(masm->instr_at(pos)));
    }
  
    static Mode GetMode(Code* stub) {
      Instr first_instruction = Assembler::instr_at(stub->instruction_start());
      Instr second_instruction = Assembler::instr_at(stub->instruction_start() +
                                                     2 * Assembler::kInstrSize);
  
      if (Assembler::IsBeq(first_instruction)) {
        return INCREMENTAL;
      }
  
      ASSERT(Assembler::IsBne(first_instruction));
  
      if (Assembler::IsBeq(second_instruction)) {
        return INCREMENTAL_COMPACTION;
      }
  
      ASSERT(Assembler::IsBne(second_instruction));
  
      return STORE_BUFFER_ONLY;
    }
  
    static void Patch(Code* stub, Mode mode) {
      MacroAssembler masm(NULL,
                          stub->instruction_start(),
                          stub->instruction_size());
      switch (mode) {
        case STORE_BUFFER_ONLY:
          ASSERT(GetMode(stub) == INCREMENTAL ||
                 GetMode(stub) == INCREMENTAL_COMPACTION);
          PatchBranchIntoNop(&masm, 0);
          PatchBranchIntoNop(&masm, 2 * Assembler::kInstrSize);
          break;
        case INCREMENTAL:
          ASSERT(GetMode(stub) == STORE_BUFFER_ONLY);
          PatchNopIntoBranch(&masm, 0);
          break;
        case INCREMENTAL_COMPACTION:
          ASSERT(GetMode(stub) == STORE_BUFFER_ONLY);
          PatchNopIntoBranch(&masm, 2 * Assembler::kInstrSize);
          break;
      }
      ASSERT(GetMode(stub) == mode);
      CPU::FlushICache(stub->instruction_start(), 4 * Assembler::kInstrSize);
    }
  
   private:
    // This is a helper class for freeing up 3 scratch registers.  The input is
    // two registers that must be preserved and one scratch register provided by
    // the caller.
    class RegisterAllocation {
     public:
      RegisterAllocation(Register object,
                         Register address,
                         Register scratch0)
          : object_(object),
            address_(address),
            scratch0_(scratch0) {
        ASSERT(!AreAliased(scratch0, object, address, no_reg));
        scratch1_ = GetRegThatIsNotOneOf(object_, address_, scratch0_);
      }
  
      void Save(MacroAssembler* masm) {
        ASSERT(!AreAliased(object_, address_, scratch1_, scratch0_));
        // We don't have to save scratch0_ because it was given to us as
        // a scratch register.
        masm->push(scratch1_);
      }
  
      void Restore(MacroAssembler* masm) {
        masm->pop(scratch1_);
      }
  
      // If we have to call into C then we need to save and restore all caller-
      // saved registers that were not already preserved.  The scratch registers
      // will be restored by other means so we don't bother pushing them here.
      void SaveCallerSaveRegisters(MacroAssembler* masm, SaveFPRegsMode mode) {
        masm->MultiPush((kJSCallerSaved | ra.bit()) & ~scratch1_.bit());
        if (mode == kSaveFPRegs) {
          CpuFeatures::Scope scope(FPU);
          masm->MultiPushFPU(kCallerSavedFPU);
        }
      }
  
      inline void RestoreCallerSaveRegisters(MacroAssembler*masm,
                                             SaveFPRegsMode mode) {
        if (mode == kSaveFPRegs) {
          CpuFeatures::Scope scope(FPU);
          masm->MultiPopFPU(kCallerSavedFPU);
        }
        masm->MultiPop((kJSCallerSaved | ra.bit()) & ~scratch1_.bit());
      }
  
      inline Register object() { return object_; }
      inline Register address() { return address_; }
      inline Register scratch0() { return scratch0_; }
      inline Register scratch1() { return scratch1_; }
  
     private:
      Register object_;
      Register address_;
      Register scratch0_;
      Register scratch1_;
  
      Register GetRegThatIsNotOneOf(Register r1,
                                    Register r2,
                                    Register r3) {
        for (int i = 0; i < Register::NumAllocatableRegisters(); i++) {
          Register candidate = Register::FromAllocationIndex(i);
          if (candidate.is(r1)) continue;
          if (candidate.is(r2)) continue;
          if (candidate.is(r3)) continue;
          return candidate;
        }
        UNREACHABLE();
        return no_reg;
      }
      friend class RecordWriteStub;
    };
  
    enum OnNoNeedToInformIncrementalMarker {
      kReturnOnNoNeedToInformIncrementalMarker,
      kUpdateRememberedSetOnNoNeedToInformIncrementalMarker
    };
  
    void Generate(MacroAssembler* masm);
    void GenerateIncremental(MacroAssembler* masm, Mode mode);
    void CheckNeedsToInformIncrementalMarker(
        MacroAssembler* masm,
        OnNoNeedToInformIncrementalMarker on_no_need,
        Mode mode);
    void InformIncrementalMarker(MacroAssembler* masm, Mode mode);
  
    Major MajorKey() { return RecordWrite; }
  
    int MinorKey() {
      return ObjectBits::encode(object_.code()) |
          ValueBits::encode(value_.code()) |
          AddressBits::encode(address_.code()) |
          RememberedSetActionBits::encode(remembered_set_action_) |
          SaveFPRegsModeBits::encode(save_fp_regs_mode_);
    }
  
    void Activate(Code* code) {
      code->GetHeap()->incremental_marking()->ActivateGeneratedStub(code);
    }
  
    class ObjectBits: public BitField<int, 0, 5> {};
    class ValueBits: public BitField<int, 5, 5> {};
    class AddressBits: public BitField<int, 10, 5> {};
    class RememberedSetActionBits: public BitField<RememberedSetAction, 15, 1> {};
    class SaveFPRegsModeBits: public BitField<SaveFPRegsMode, 16, 1> {};
  
    Register object_;
    Register value_;
    Register address_;
    RememberedSetAction remembered_set_action_;
    SaveFPRegsMode save_fp_regs_mode_;
    Label slow_;
    RegisterAllocation regs_;
  };
  
  
  // Enter C code from generated RegExp code in a way that allows
  // the C code to fix the return address in case of a GC.
  // Currently only needed on ARM and MIPS.
  class RegExpCEntryStub: public PlatformCodeStub {
   public:
    RegExpCEntryStub() {}
    virtual ~RegExpCEntryStub() {}
    void Generate(MacroAssembler* masm);
  
   private:
    Major MajorKey() { return RegExpCEntry; }
    int MinorKey() { return 0; }
  
    bool NeedsImmovableCode() { return true; }
  };
  
  // Trampoline stub to call into native code. To call safely into native code
  // in the presence of compacting GC (which can move code objects) we need to
  // keep the code which called into native pinned in the memory. Currently the
  // simplest approach is to generate such stub early enough so it can never be
  // moved by GC
  class DirectCEntryStub: public PlatformCodeStub {
   public:
    DirectCEntryStub() {}
    void Generate(MacroAssembler* masm);
    void GenerateCall(MacroAssembler* masm,
                                  ExternalReference function);
    void GenerateCall(MacroAssembler* masm, Register target);
  
   private:
    Major MajorKey() { return DirectCEntry; }
    int MinorKey() { return 0; }
  
    bool NeedsImmovableCode() { return true; }
  };
  
  class FloatingPointHelper : public AllStatic {
   public:
    enum Destination {
      kFPURegisters,
      kCoreRegisters
    };
  
  
    // Loads smis from a0 and a1 (right and left in binary operations) into
    // floating point registers. Depending on the destination the values ends up
    // either f14 and f12 or in a2/a3 and a0/a1 respectively. If the destination
    // is floating point registers FPU must be supported. If core registers are
    // requested when FPU is supported f12 and f14 will be scratched.
    static void LoadSmis(MacroAssembler* masm,
                         Destination destination,
                         Register scratch1,
                         Register scratch2);
  
    // Convert the smi or heap number in object to an int32 using the rules
    // for ToInt32 as described in ECMAScript 9.5.: the value is truncated
    // and brought into the range -2^31 .. +2^31 - 1.
    static void ConvertNumberToInt32(MacroAssembler* masm,
                                     Register object,
                                     Register dst,
                                     Register heap_number_map,
                                     Register scratch1,
                                     Register scratch2,
                                     Register scratch3,
                                     FPURegister double_scratch,
                                     Label* not_int32);
  
    // Converts the integer (untagged smi) in |int_scratch| to a double, storing
    // the result either in |double_dst| or |dst2:dst1|, depending on
    // |destination|.
    // Warning: The value in |int_scratch| will be changed in the process!
    static void ConvertIntToDouble(MacroAssembler* masm,
                                   Register int_scratch,
                                   Destination destination,
                                   FPURegister double_dst,
                                   Register dst1,
                                   Register dst2,
                                   Register scratch2,
                                   FPURegister single_scratch);
  
    // Load the number from object into double_dst in the double format.
    // Control will jump to not_int32 if the value cannot be exactly represented
    // by a 32-bit integer.
    // Floating point value in the 32-bit integer range that are not exact integer
    // won't be loaded.
    static void LoadNumberAsInt32Double(MacroAssembler* masm,
                                        Register object,
                                        Destination destination,
                                        FPURegister double_dst,
                                        FPURegister double_scratch,
                                        Register dst1,
                                        Register dst2,
                                        Register heap_number_map,
                                        Register scratch1,
                                        Register scratch2,
                                        FPURegister single_scratch,
                                        Label* not_int32);
  
    // Loads the number from object into dst as a 32-bit integer.
    // Control will jump to not_int32 if the object cannot be exactly represented
    // by a 32-bit integer.
    // Floating point value in the 32-bit integer range that are not exact integer
    // won't be converted.
    // scratch3 is not used when FPU is supported.
    static void LoadNumberAsInt32(MacroAssembler* masm,
                                  Register object,
                                  Register dst,
                                  Register heap_number_map,
                                  Register scratch1,
                                  Register scratch2,
                                  Register scratch3,
                                  FPURegister double_scratch0,
                                  FPURegister double_scratch1,
                                  Label* not_int32);
  
    // Generate non FPU code to check if a double can be exactly represented by a
    // 32-bit integer. This does not check for 0 or -0, which need
    // to be checked for separately.
    // Control jumps to not_int32 if the value is not a 32-bit integer, and falls
    // through otherwise.
    // src1 and src2 will be cloberred.
    //
    // Expected input:
    // - src1: higher (exponent) part of the double value.
    // - src2: lower (mantissa) part of the double value.
    // Output status:
    // - dst: 32 higher bits of the mantissa. (mantissa[51:20])
    // - src2: contains 1.
    // - other registers are clobbered.
    static void DoubleIs32BitInteger(MacroAssembler* masm,
                                     Register src1,
                                     Register src2,
                                     Register dst,
                                     Register scratch,
                                     Label* not_int32);
  
    // Generates code to call a C function to do a double operation using core
    // registers. (Used when FPU is not supported.)
    // This code never falls through, but returns with a heap number containing
    // the result in v0.
    // Register heapnumber_result must be a heap number in which the
    // result of the operation will be stored.
    // Requires the following layout on entry:
    // a0: Left value (least significant part of mantissa).
    // a1: Left value (sign, exponent, top of mantissa).
    // a2: Right value (least significant part of mantissa).
    // a3: Right value (sign, exponent, top of mantissa).
    static void CallCCodeForDoubleOperation(MacroAssembler* masm,
                                            Token::Value op,
                                            Register heap_number_result,
                                            Register scratch);
  
    // Loads the objects from |object| into floating point registers.
    // Depending on |destination| the value ends up either in |dst| or
    // in |dst1|/|dst2|. If |destination| is kFPURegisters, then FPU
    // must be supported. If kCoreRegisters are requested and FPU is
    // supported, |dst| will be scratched. If |object| is neither smi nor
    // heap number, |not_number| is jumped to with |object| still intact.
    static void LoadNumber(MacroAssembler* masm,
                           FloatingPointHelper::Destination destination,
                           Register object,
                           FPURegister dst,
                           Register dst1,
                           Register dst2,
                           Register heap_number_map,
                           Register scratch1,
                           Register scratch2,
                           Label* not_number);
  };
  
  
  class StringDictionaryLookupStub: public PlatformCodeStub {
   public:
    enum LookupMode { POSITIVE_LOOKUP, NEGATIVE_LOOKUP };
  
    explicit StringDictionaryLookupStub(LookupMode mode) : mode_(mode) { }
  
    void Generate(MacroAssembler* masm);
  
    static void GenerateNegativeLookup(MacroAssembler* masm,
                                       Label* miss,
                                       Label* done,
                                       Register receiver,
                                       Register properties,
                                       Handle<String> name,
                                       Register scratch0);
  
    static void GeneratePositiveLookup(MacroAssembler* masm,
                                       Label* miss,
                                       Label* done,
                                       Register elements,
                                       Register name,
                                       Register r0,
                                       Register r1);
  
    virtual bool SometimesSetsUpAFrame() { return false; }
  
   private:
    static const int kInlinedProbes = 4;
    static const int kTotalProbes = 20;
  
    static const int kCapacityOffset =
        StringDictionary::kHeaderSize +
        StringDictionary::kCapacityIndex * kPointerSize;
  
    static const int kElementsStartOffset =
        StringDictionary::kHeaderSize +
        StringDictionary::kElementsStartIndex * kPointerSize;
  
    Major MajorKey() { return StringDictionaryLookup; }
  
    int MinorKey() {
      return LookupModeBits::encode(mode_);
    }
  
    class LookupModeBits: public BitField<LookupMode, 0, 1> {};
  
    LookupMode mode_;
  };
  
  
  } }  // namespace v8::internal
  
  #endif  // V8_MIPS_CODE_STUBS_ARM_H_
  