| Index: src/code-stubs.h
 | 
| ===================================================================
 | 
| --- src/code-stubs.h	(revision 5369)
 | 
| +++ src/code-stubs.h	(working copy)
 | 
| @@ -29,6 +29,7 @@
 | 
|  #define V8_CODE_STUBS_H_
 | 
|  
 | 
|  #include "globals.h"
 | 
| +#include "macro-assembler.h"
 | 
|  
 | 
|  namespace v8 {
 | 
|  namespace internal {
 | 
| @@ -80,6 +81,14 @@
 | 
|    CODE_STUB_LIST_ALL_PLATFORMS(V)    \
 | 
|    CODE_STUB_LIST_ARM(V)
 | 
|  
 | 
| +// Types of uncatchable exceptions.
 | 
| +enum UncatchableExceptionType { OUT_OF_MEMORY, TERMINATION };
 | 
| +
 | 
| +// Mode to overwrite BinaryExpression values.
 | 
| +enum OverwriteMode { NO_OVERWRITE, OVERWRITE_LEFT, OVERWRITE_RIGHT };
 | 
| +enum UnaryOverwriteMode { UNARY_OVERWRITE, UNARY_NO_OVERWRITE };
 | 
| +
 | 
| +
 | 
|  // Stub is base classes of all stubs.
 | 
|  class CodeStub BASE_EMBEDDED {
 | 
|   public:
 | 
| @@ -105,6 +114,12 @@
 | 
|    static int MinorKeyFromKey(uint32_t key) {
 | 
|      return MinorKeyBits::decode(key);
 | 
|    };
 | 
| +
 | 
| +  // Gets the major key from a code object that is a code stub or binary op IC.
 | 
| +  static Major GetMajorKey(Code* code_stub) {
 | 
| +    return static_cast<Major>(code_stub->major_key());
 | 
| +  }
 | 
| +
 | 
|    static const char* MajorName(Major major_key, bool allow_unknown_keys);
 | 
|  
 | 
|    virtual ~CodeStub() {}
 | 
| @@ -172,6 +187,609 @@
 | 
|    friend class BreakPointIterator;
 | 
|  };
 | 
|  
 | 
| +
 | 
| +// Helper interface to prepare to/restore after making runtime calls.
 | 
| +class RuntimeCallHelper {
 | 
| + public:
 | 
| +  virtual ~RuntimeCallHelper() {}
 | 
| +
 | 
| +  virtual void BeforeCall(MacroAssembler* masm) const = 0;
 | 
| +
 | 
| +  virtual void AfterCall(MacroAssembler* masm) const = 0;
 | 
| +
 | 
| + protected:
 | 
| +  RuntimeCallHelper() {}
 | 
| +
 | 
| + private:
 | 
| +  DISALLOW_COPY_AND_ASSIGN(RuntimeCallHelper);
 | 
| +};
 | 
| +
 | 
|  } }  // namespace v8::internal
 | 
|  
 | 
| +#if V8_TARGET_ARCH_IA32
 | 
| +#include "ia32/code-stubs-ia32.h"
 | 
| +#elif V8_TARGET_ARCH_X64
 | 
| +#include "x64/code-stubs-x64.h"
 | 
| +#elif V8_TARGET_ARCH_ARM
 | 
| +#include "arm/code-stubs-arm.h"
 | 
| +#elif V8_TARGET_ARCH_MIPS
 | 
| +#include "mips/code-stubs-mips.h"
 | 
| +#else
 | 
| +#error Unsupported target architecture.
 | 
| +#endif
 | 
| +
 | 
| +namespace v8 {
 | 
| +namespace internal {
 | 
| +
 | 
| +
 | 
| +// RuntimeCallHelper implementation used in IC stubs: enters/leaves a
 | 
| +// newly created internal frame before/after the runtime call.
 | 
| +class ICRuntimeCallHelper : public RuntimeCallHelper {
 | 
| + public:
 | 
| +  ICRuntimeCallHelper() {}
 | 
| +
 | 
| +  virtual void BeforeCall(MacroAssembler* masm) const;
 | 
| +
 | 
| +  virtual void AfterCall(MacroAssembler* masm) const;
 | 
| +};
 | 
| +
 | 
| +
 | 
| +// Trivial RuntimeCallHelper implementation.
 | 
| +class NopRuntimeCallHelper : public RuntimeCallHelper {
 | 
| + public:
 | 
| +  NopRuntimeCallHelper() {}
 | 
| +
 | 
| +  virtual void BeforeCall(MacroAssembler* masm) const {}
 | 
| +
 | 
| +  virtual void AfterCall(MacroAssembler* masm) const {}
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class StackCheckStub : public CodeStub {
 | 
| + public:
 | 
| +  StackCheckStub() { }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +
 | 
| + private:
 | 
| +
 | 
| +  const char* GetName() { return "StackCheckStub"; }
 | 
| +
 | 
| +  Major MajorKey() { return StackCheck; }
 | 
| +  int MinorKey() { return 0; }
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class FastNewClosureStub : public CodeStub {
 | 
| + public:
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +
 | 
| + private:
 | 
| +  const char* GetName() { return "FastNewClosureStub"; }
 | 
| +  Major MajorKey() { return FastNewClosure; }
 | 
| +  int MinorKey() { return 0; }
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class FastNewContextStub : public CodeStub {
 | 
| + public:
 | 
| +  static const int kMaximumSlots = 64;
 | 
| +
 | 
| +  explicit FastNewContextStub(int slots) : slots_(slots) {
 | 
| +    ASSERT(slots_ > 0 && slots <= kMaximumSlots);
 | 
| +  }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +
 | 
| + private:
 | 
| +  int slots_;
 | 
| +
 | 
| +  const char* GetName() { return "FastNewContextStub"; }
 | 
| +  Major MajorKey() { return FastNewContext; }
 | 
| +  int MinorKey() { return slots_; }
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class FastCloneShallowArrayStub : public CodeStub {
 | 
| + public:
 | 
| +  // Maximum length of copied elements array.
 | 
| +  static const int kMaximumClonedLength = 8;
 | 
| +
 | 
| +  enum Mode {
 | 
| +    CLONE_ELEMENTS,
 | 
| +    COPY_ON_WRITE_ELEMENTS
 | 
| +  };
 | 
| +
 | 
| +  FastCloneShallowArrayStub(Mode mode, int length)
 | 
| +      : mode_(mode),
 | 
| +        length_((mode == COPY_ON_WRITE_ELEMENTS) ? 0 : length) {
 | 
| +    ASSERT(length_ >= 0);
 | 
| +    ASSERT(length_ <= kMaximumClonedLength);
 | 
| +  }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +
 | 
| + private:
 | 
| +  Mode mode_;
 | 
| +  int length_;
 | 
| +
 | 
| +  const char* GetName() { return "FastCloneShallowArrayStub"; }
 | 
| +  Major MajorKey() { return FastCloneShallowArray; }
 | 
| +  int MinorKey() {
 | 
| +    ASSERT(mode_ == 0 || mode_ == 1);
 | 
| +    return (length_ << 1) | mode_;
 | 
| +  }
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class InstanceofStub: public CodeStub {
 | 
| + public:
 | 
| +  InstanceofStub() { }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +
 | 
| + private:
 | 
| +  Major MajorKey() { return Instanceof; }
 | 
| +  int MinorKey() { return 0; }
 | 
| +};
 | 
| +
 | 
| +
 | 
| +enum NegativeZeroHandling {
 | 
| +  kStrictNegativeZero,
 | 
| +  kIgnoreNegativeZero
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class GenericUnaryOpStub : public CodeStub {
 | 
| + public:
 | 
| +  GenericUnaryOpStub(Token::Value op,
 | 
| +                     UnaryOverwriteMode overwrite,
 | 
| +                     NegativeZeroHandling negative_zero = kStrictNegativeZero)
 | 
| +      : op_(op), overwrite_(overwrite), negative_zero_(negative_zero) { }
 | 
| +
 | 
| + private:
 | 
| +  Token::Value op_;
 | 
| +  UnaryOverwriteMode overwrite_;
 | 
| +  NegativeZeroHandling negative_zero_;
 | 
| +
 | 
| +  class OverwriteField: public BitField<UnaryOverwriteMode, 0, 1> {};
 | 
| +  class NegativeZeroField: public BitField<NegativeZeroHandling, 1, 1> {};
 | 
| +  class OpField: public BitField<Token::Value, 2, kMinorBits - 2> {};
 | 
| +
 | 
| +  Major MajorKey() { return GenericUnaryOp; }
 | 
| +  int MinorKey() {
 | 
| +    return OpField::encode(op_) |
 | 
| +           OverwriteField::encode(overwrite_) |
 | 
| +           NegativeZeroField::encode(negative_zero_);
 | 
| +  }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +
 | 
| +  const char* GetName();
 | 
| +};
 | 
| +
 | 
| +
 | 
| +enum NaNInformation {
 | 
| +  kBothCouldBeNaN,
 | 
| +  kCantBothBeNaN
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class CompareStub: public CodeStub {
 | 
| + public:
 | 
| +  CompareStub(Condition cc,
 | 
| +              bool strict,
 | 
| +              NaNInformation nan_info = kBothCouldBeNaN,
 | 
| +              bool include_number_compare = true,
 | 
| +              Register lhs = no_reg,
 | 
| +              Register rhs = no_reg) :
 | 
| +      cc_(cc),
 | 
| +      strict_(strict),
 | 
| +      never_nan_nan_(nan_info == kCantBothBeNaN),
 | 
| +      include_number_compare_(include_number_compare),
 | 
| +      lhs_(lhs),
 | 
| +      rhs_(rhs),
 | 
| +      name_(NULL) { }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +
 | 
| + private:
 | 
| +  Condition cc_;
 | 
| +  bool strict_;
 | 
| +  // Only used for 'equal' comparisons.  Tells the stub that we already know
 | 
| +  // that at least one side of the comparison is not NaN.  This allows the
 | 
| +  // stub to use object identity in the positive case.  We ignore it when
 | 
| +  // generating the minor key for other comparisons to avoid creating more
 | 
| +  // stubs.
 | 
| +  bool never_nan_nan_;
 | 
| +  // Do generate the number comparison code in the stub. Stubs without number
 | 
| +  // comparison code is used when the number comparison has been inlined, and
 | 
| +  // the stub will be called if one of the operands is not a number.
 | 
| +  bool include_number_compare_;
 | 
| +  // Register holding the left hand side of the comparison if the stub gives
 | 
| +  // a choice, no_reg otherwise.
 | 
| +  Register lhs_;
 | 
| +  // Register holding the right hand side of the comparison if the stub gives
 | 
| +  // a choice, no_reg otherwise.
 | 
| +  Register rhs_;
 | 
| +
 | 
| +  // Encoding of the minor key CCCCCCCCCCCCRCNS.
 | 
| +  class StrictField: public BitField<bool, 0, 1> {};
 | 
| +  class NeverNanNanField: public BitField<bool, 1, 1> {};
 | 
| +  class IncludeNumberCompareField: public BitField<bool, 2, 1> {};
 | 
| +  class RegisterField: public BitField<bool, 3, 1> {};
 | 
| +  class ConditionField: public BitField<int, 4, 12> {};
 | 
| +
 | 
| +  Major MajorKey() { return Compare; }
 | 
| +
 | 
| +  int MinorKey();
 | 
| +
 | 
| +  // Branch to the label if the given object isn't a symbol.
 | 
| +  void BranchIfNonSymbol(MacroAssembler* masm,
 | 
| +                         Label* label,
 | 
| +                         Register object,
 | 
| +                         Register scratch);
 | 
| +
 | 
| +  // Unfortunately you have to run without snapshots to see most of these
 | 
| +  // names in the profile since most compare stubs end up in the snapshot.
 | 
| +  char* name_;
 | 
| +  const char* GetName();
 | 
| +#ifdef DEBUG
 | 
| +  void Print() {
 | 
| +    PrintF("CompareStub (cc %d), (strict %s), "
 | 
| +           "(never_nan_nan %s), (number_compare %s) ",
 | 
| +           static_cast<int>(cc_),
 | 
| +           strict_ ? "true" : "false",
 | 
| +           never_nan_nan_ ? "true" : "false",
 | 
| +           include_number_compare_ ? "included" : "not included");
 | 
| +
 | 
| +    if (!lhs_.is(no_reg) && !rhs_.is(no_reg)) {
 | 
| +      PrintF("(lhs r%d), (rhs r%d)\n", lhs_.code(), rhs_.code());
 | 
| +    } else {
 | 
| +      PrintF("\n");
 | 
| +    }
 | 
| +  }
 | 
| +#endif
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class CEntryStub : public CodeStub {
 | 
| + public:
 | 
| +  explicit CEntryStub(int result_size) : result_size_(result_size) { }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +
 | 
| + private:
 | 
| +  void GenerateCore(MacroAssembler* masm,
 | 
| +                    Label* throw_normal_exception,
 | 
| +                    Label* throw_termination_exception,
 | 
| +                    Label* throw_out_of_memory_exception,
 | 
| +                    bool do_gc,
 | 
| +                    bool always_allocate_scope,
 | 
| +                    int alignment_skew = 0);
 | 
| +  void GenerateThrowTOS(MacroAssembler* masm);
 | 
| +  void GenerateThrowUncatchable(MacroAssembler* masm,
 | 
| +                                UncatchableExceptionType type);
 | 
| +
 | 
| +  // Number of pointers/values returned.
 | 
| +  const int result_size_;
 | 
| +
 | 
| +  Major MajorKey() { return CEntry; }
 | 
| +  // Minor key must differ if different result_size_ values means different
 | 
| +  // code is generated.
 | 
| +  int MinorKey();
 | 
| +
 | 
| +  const char* GetName() { return "CEntryStub"; }
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class ApiGetterEntryStub : public CodeStub {
 | 
| + public:
 | 
| +  ApiGetterEntryStub(Handle<AccessorInfo> info,
 | 
| +                     ApiFunction* fun)
 | 
| +      : info_(info),
 | 
| +        fun_(fun) { }
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +  virtual bool has_custom_cache() { return true; }
 | 
| +  virtual bool GetCustomCache(Code** code_out);
 | 
| +  virtual void SetCustomCache(Code* value);
 | 
| +
 | 
| +  static const int kStackSpace = 5;
 | 
| +  static const int kArgc = 4;
 | 
| + private:
 | 
| +  Handle<AccessorInfo> info() { return info_; }
 | 
| +  ApiFunction* fun() { return fun_; }
 | 
| +  Major MajorKey() { return NoCache; }
 | 
| +  int MinorKey() { return 0; }
 | 
| +  const char* GetName() { return "ApiEntryStub"; }
 | 
| +  // The accessor info associated with the function.
 | 
| +  Handle<AccessorInfo> info_;
 | 
| +  // The function to be called.
 | 
| +  ApiFunction* fun_;
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class JSEntryStub : public CodeStub {
 | 
| + public:
 | 
| +  JSEntryStub() { }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm) { GenerateBody(masm, false); }
 | 
| +
 | 
| + protected:
 | 
| +  void GenerateBody(MacroAssembler* masm, bool is_construct);
 | 
| +
 | 
| + private:
 | 
| +  Major MajorKey() { return JSEntry; }
 | 
| +  int MinorKey() { return 0; }
 | 
| +
 | 
| +  const char* GetName() { return "JSEntryStub"; }
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class JSConstructEntryStub : public JSEntryStub {
 | 
| + public:
 | 
| +  JSConstructEntryStub() { }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm) { GenerateBody(masm, true); }
 | 
| +
 | 
| + private:
 | 
| +  int MinorKey() { return 1; }
 | 
| +
 | 
| +  const char* GetName() { return "JSConstructEntryStub"; }
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class ArgumentsAccessStub: public CodeStub {
 | 
| + public:
 | 
| +  enum Type {
 | 
| +    READ_ELEMENT,
 | 
| +    NEW_OBJECT
 | 
| +  };
 | 
| +
 | 
| +  explicit ArgumentsAccessStub(Type type) : type_(type) { }
 | 
| +
 | 
| + private:
 | 
| +  Type type_;
 | 
| +
 | 
| +  Major MajorKey() { return ArgumentsAccess; }
 | 
| +  int MinorKey() { return type_; }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +  void GenerateReadElement(MacroAssembler* masm);
 | 
| +  void GenerateNewObject(MacroAssembler* masm);
 | 
| +
 | 
| +  const char* GetName() { return "ArgumentsAccessStub"; }
 | 
| +
 | 
| +#ifdef DEBUG
 | 
| +  void Print() {
 | 
| +    PrintF("ArgumentsAccessStub (type %d)\n", type_);
 | 
| +  }
 | 
| +#endif
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class RegExpExecStub: public CodeStub {
 | 
| + public:
 | 
| +  RegExpExecStub() { }
 | 
| +
 | 
| + private:
 | 
| +  Major MajorKey() { return RegExpExec; }
 | 
| +  int MinorKey() { return 0; }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +
 | 
| +  const char* GetName() { return "RegExpExecStub"; }
 | 
| +
 | 
| +#ifdef DEBUG
 | 
| +  void Print() {
 | 
| +    PrintF("RegExpExecStub\n");
 | 
| +  }
 | 
| +#endif
 | 
| +};
 | 
| +
 | 
| +
 | 
| +class CallFunctionStub: public CodeStub {
 | 
| + public:
 | 
| +  CallFunctionStub(int argc, InLoopFlag in_loop, CallFunctionFlags flags)
 | 
| +      : argc_(argc), in_loop_(in_loop), flags_(flags) { }
 | 
| +
 | 
| +  void Generate(MacroAssembler* masm);
 | 
| +
 | 
| + private:
 | 
| +  int argc_;
 | 
| +  InLoopFlag in_loop_;
 | 
| +  CallFunctionFlags flags_;
 | 
| +
 | 
| +#ifdef DEBUG
 | 
| +  void Print() {
 | 
| +    PrintF("CallFunctionStub (args %d, in_loop %d, flags %d)\n",
 | 
| +           argc_,
 | 
| +           static_cast<int>(in_loop_),
 | 
| +           static_cast<int>(flags_));
 | 
| +  }
 | 
| +#endif
 | 
| +
 | 
| +  // Minor key encoding in 32 bits with Bitfield <Type, shift, size>.
 | 
| +  class InLoopBits: public BitField<InLoopFlag, 0, 1> {};
 | 
| +  class FlagBits: public BitField<CallFunctionFlags, 1, 1> {};
 | 
| +  class ArgcBits: public BitField<int, 2, 32 - 2> {};
 | 
| +
 | 
| +  Major MajorKey() { return CallFunction; }
 | 
| +  int MinorKey() {
 | 
| +    // Encode the parameters in a unique 32 bit value.
 | 
| +    return InLoopBits::encode(in_loop_)
 | 
| +           | FlagBits::encode(flags_)
 | 
| +           | ArgcBits::encode(argc_);
 | 
| +  }
 | 
| +
 | 
| +  InLoopFlag InLoop() { return in_loop_; }
 | 
| +  bool ReceiverMightBeValue() {
 | 
| +    return (flags_ & RECEIVER_MIGHT_BE_VALUE) != 0;
 | 
| +  }
 | 
| +
 | 
| + public:
 | 
| +  static int ExtractArgcFromMinorKey(int minor_key) {
 | 
| +    return ArgcBits::decode(minor_key);
 | 
| +  }
 | 
| +};
 | 
| +
 | 
| +
 | 
| +enum StringIndexFlags {
 | 
| +  // Accepts smis or heap numbers.
 | 
| +  STRING_INDEX_IS_NUMBER,
 | 
| +
 | 
| +  // Accepts smis or heap numbers that are valid array indices
 | 
| +  // (ECMA-262 15.4). Invalid indices are reported as being out of
 | 
| +  // range.
 | 
| +  STRING_INDEX_IS_ARRAY_INDEX
 | 
| +};
 | 
| +
 | 
| +
 | 
| +// Generates code implementing String.prototype.charCodeAt.
 | 
| +//
 | 
| +// Only supports the case when the receiver is a string and the index
 | 
| +// is a number (smi or heap number) that is a valid index into the
 | 
| +// string. Additional index constraints are specified by the
 | 
| +// flags. Otherwise, bails out to the provided labels.
 | 
| +//
 | 
| +// Register usage: |object| may be changed to another string in a way
 | 
| +// that doesn't affect charCodeAt/charAt semantics, |index| is
 | 
| +// preserved, |scratch| and |result| are clobbered.
 | 
| +class StringCharCodeAtGenerator {
 | 
| + public:
 | 
| +  StringCharCodeAtGenerator(Register object,
 | 
| +                            Register index,
 | 
| +                            Register scratch,
 | 
| +                            Register result,
 | 
| +                            Label* receiver_not_string,
 | 
| +                            Label* index_not_number,
 | 
| +                            Label* index_out_of_range,
 | 
| +                            StringIndexFlags index_flags)
 | 
| +      : object_(object),
 | 
| +        index_(index),
 | 
| +        scratch_(scratch),
 | 
| +        result_(result),
 | 
| +        receiver_not_string_(receiver_not_string),
 | 
| +        index_not_number_(index_not_number),
 | 
| +        index_out_of_range_(index_out_of_range),
 | 
| +        index_flags_(index_flags) {
 | 
| +    ASSERT(!scratch_.is(object_));
 | 
| +    ASSERT(!scratch_.is(index_));
 | 
| +    ASSERT(!scratch_.is(result_));
 | 
| +    ASSERT(!result_.is(object_));
 | 
| +    ASSERT(!result_.is(index_));
 | 
| +  }
 | 
| +
 | 
| +  // Generates the fast case code. On the fallthrough path |result|
 | 
| +  // register contains the result.
 | 
| +  void GenerateFast(MacroAssembler* masm);
 | 
| +
 | 
| +  // Generates the slow case code. Must not be naturally
 | 
| +  // reachable. Expected to be put after a ret instruction (e.g., in
 | 
| +  // deferred code). Always jumps back to the fast case.
 | 
| +  void GenerateSlow(MacroAssembler* masm,
 | 
| +                    const RuntimeCallHelper& call_helper);
 | 
| +
 | 
| + private:
 | 
| +  Register object_;
 | 
| +  Register index_;
 | 
| +  Register scratch_;
 | 
| +  Register result_;
 | 
| +
 | 
| +  Label* receiver_not_string_;
 | 
| +  Label* index_not_number_;
 | 
| +  Label* index_out_of_range_;
 | 
| +
 | 
| +  StringIndexFlags index_flags_;
 | 
| +
 | 
| +  Label call_runtime_;
 | 
| +  Label index_not_smi_;
 | 
| +  Label got_smi_index_;
 | 
| +  Label exit_;
 | 
| +
 | 
| +  DISALLOW_COPY_AND_ASSIGN(StringCharCodeAtGenerator);
 | 
| +};
 | 
| +
 | 
| +
 | 
| +// Generates code for creating a one-char string from a char code.
 | 
| +class StringCharFromCodeGenerator {
 | 
| + public:
 | 
| +  StringCharFromCodeGenerator(Register code,
 | 
| +                              Register result)
 | 
| +      : code_(code),
 | 
| +        result_(result) {
 | 
| +    ASSERT(!code_.is(result_));
 | 
| +  }
 | 
| +
 | 
| +  // Generates the fast case code. On the fallthrough path |result|
 | 
| +  // register contains the result.
 | 
| +  void GenerateFast(MacroAssembler* masm);
 | 
| +
 | 
| +  // Generates the slow case code. Must not be naturally
 | 
| +  // reachable. Expected to be put after a ret instruction (e.g., in
 | 
| +  // deferred code). Always jumps back to the fast case.
 | 
| +  void GenerateSlow(MacroAssembler* masm,
 | 
| +                    const RuntimeCallHelper& call_helper);
 | 
| +
 | 
| + private:
 | 
| +  Register code_;
 | 
| +  Register result_;
 | 
| +
 | 
| +  Label slow_case_;
 | 
| +  Label exit_;
 | 
| +
 | 
| +  DISALLOW_COPY_AND_ASSIGN(StringCharFromCodeGenerator);
 | 
| +};
 | 
| +
 | 
| +
 | 
| +// Generates code implementing String.prototype.charAt.
 | 
| +//
 | 
| +// Only supports the case when the receiver is a string and the index
 | 
| +// is a number (smi or heap number) that is a valid index into the
 | 
| +// string. Additional index constraints are specified by the
 | 
| +// flags. Otherwise, bails out to the provided labels.
 | 
| +//
 | 
| +// Register usage: |object| may be changed to another string in a way
 | 
| +// that doesn't affect charCodeAt/charAt semantics, |index| is
 | 
| +// preserved, |scratch1|, |scratch2|, and |result| are clobbered.
 | 
| +class StringCharAtGenerator {
 | 
| + public:
 | 
| +  StringCharAtGenerator(Register object,
 | 
| +                        Register index,
 | 
| +                        Register scratch1,
 | 
| +                        Register scratch2,
 | 
| +                        Register result,
 | 
| +                        Label* receiver_not_string,
 | 
| +                        Label* index_not_number,
 | 
| +                        Label* index_out_of_range,
 | 
| +                        StringIndexFlags index_flags)
 | 
| +      : char_code_at_generator_(object,
 | 
| +                                index,
 | 
| +                                scratch1,
 | 
| +                                scratch2,
 | 
| +                                receiver_not_string,
 | 
| +                                index_not_number,
 | 
| +                                index_out_of_range,
 | 
| +                                index_flags),
 | 
| +        char_from_code_generator_(scratch2, result) {}
 | 
| +
 | 
| +  // Generates the fast case code. On the fallthrough path |result|
 | 
| +  // register contains the result.
 | 
| +  void GenerateFast(MacroAssembler* masm);
 | 
| +
 | 
| +  // Generates the slow case code. Must not be naturally
 | 
| +  // reachable. Expected to be put after a ret instruction (e.g., in
 | 
| +  // deferred code). Always jumps back to the fast case.
 | 
| +  void GenerateSlow(MacroAssembler* masm,
 | 
| +                    const RuntimeCallHelper& call_helper);
 | 
| +
 | 
| + private:
 | 
| +  StringCharCodeAtGenerator char_code_at_generator_;
 | 
| +  StringCharFromCodeGenerator char_from_code_generator_;
 | 
| +
 | 
| +  DISALLOW_COPY_AND_ASSIGN(StringCharAtGenerator);
 | 
| +};
 | 
| +
 | 
| +} }  // namespace v8::internal
 | 
| +
 | 
|  #endif  // V8_CODE_STUBS_H_
 | 
| 
 |