| Index: src/codegen.h
 | 
| ===================================================================
 | 
| --- src/codegen.h	(revision 5369)
 | 
| +++ src/codegen.h	(working copy)
 | 
| @@ -73,13 +73,6 @@
 | 
|  //   CodeForSourcePosition
 | 
|  
 | 
|  
 | 
| -// Mode to overwrite BinaryExpression values.
 | 
| -enum OverwriteMode { NO_OVERWRITE, OVERWRITE_LEFT, OVERWRITE_RIGHT };
 | 
| -enum UnaryOverwriteMode { UNARY_OVERWRITE, UNARY_NO_OVERWRITE };
 | 
| -
 | 
| -// Types of uncatchable exceptions.
 | 
| -enum UncatchableExceptionType { OUT_OF_MEMORY, TERMINATION };
 | 
| -
 | 
|  #define INLINE_RUNTIME_FUNCTION_LIST(F) \
 | 
|    F(IsSmi, 1, 1)                                                             \
 | 
|    F(IsNonNegativeSmi, 1, 1)                                                  \
 | 
| @@ -138,29 +131,6 @@
 | 
|  namespace v8 {
 | 
|  namespace internal {
 | 
|  
 | 
| -// Support for "structured" code comments.
 | 
| -#ifdef DEBUG
 | 
| -
 | 
| -class Comment BASE_EMBEDDED {
 | 
| - public:
 | 
| -  Comment(MacroAssembler* masm, const char* msg);
 | 
| -  ~Comment();
 | 
| -
 | 
| - private:
 | 
| -  MacroAssembler* masm_;
 | 
| -  const char* msg_;
 | 
| -};
 | 
| -
 | 
| -#else
 | 
| -
 | 
| -class Comment BASE_EMBEDDED {
 | 
| - public:
 | 
| -  Comment(MacroAssembler*, const char*)  {}
 | 
| -};
 | 
| -
 | 
| -#endif  // DEBUG
 | 
| -
 | 
| -
 | 
|  // Code generation can be nested.  Code generation scopes form a stack
 | 
|  // of active code generators.
 | 
|  class CodeGeneratorScope BASE_EMBEDDED {
 | 
| @@ -233,23 +203,6 @@
 | 
|  #endif
 | 
|  
 | 
|  
 | 
| -// 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);
 | 
| -};
 | 
| -
 | 
| -
 | 
|  // RuntimeCallHelper implementation that saves/restores state of a
 | 
|  // virtual frame.
 | 
|  class VirtualFrameRuntimeCallHelper : public RuntimeCallHelper {
 | 
| @@ -267,29 +220,6 @@
 | 
|  };
 | 
|  
 | 
|  
 | 
| -// 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 {}
 | 
| -};
 | 
| -
 | 
| -
 | 
|  // Deferred code objects are small pieces of code that are compiled
 | 
|  // out of line. They are used to defer the compilation of uncommon
 | 
|  // paths thereby avoiding expensive jumps around uncommon code parts.
 | 
| @@ -352,556 +282,7 @@
 | 
|    DISALLOW_COPY_AND_ASSIGN(DeferredCode);
 | 
|  };
 | 
|  
 | 
| -class StackCheckStub : public CodeStub {
 | 
| - public:
 | 
| -  StackCheckStub() { }
 | 
|  
 | 
| -  void Generate(MacroAssembler* masm);
 | 
| +} }  // namespace v8::internal
 | 
|  
 | 
| - 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_;
 | 
| -
 | 
| -  // Minor key encoding
 | 
| -  class IndirectResultBits: public BitField<bool, 1, 1> {};
 | 
| -
 | 
| -  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 {
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| - public:
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| -  StringCharFromCodeGenerator(Register code,
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| -                              Register result)
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| -      : code_(code),
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| -        result_(result) {
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| -    ASSERT(!code_.is(result_));
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| -  }
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| -
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| -  // Generates the fast case code. On the fallthrough path |result|
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| -  // register contains the result.
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| -  void GenerateFast(MacroAssembler* masm);
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| -
 | 
| -  // Generates the slow case code. Must not be naturally
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| -  // reachable. Expected to be put after a ret instruction (e.g., in
 | 
| -  // deferred code). Always jumps back to the fast case.
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| -  void GenerateSlow(MacroAssembler* masm,
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| -                    const RuntimeCallHelper& call_helper);
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| -
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| - private:
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| -  Register code_;
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| -  Register result_;
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| -
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| -  Label slow_case_;
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| -  Label exit_;
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| -
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| -  DISALLOW_COPY_AND_ASSIGN(StringCharFromCodeGenerator);
 | 
| -};
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| -
 | 
| -
 | 
| -// 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 {
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| - public:
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| -  StringCharAtGenerator(Register object,
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| -                        Register index,
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| -                        Register scratch1,
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| -                        Register scratch2,
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| -                        Register result,
 | 
| -                        Label* receiver_not_string,
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| -                        Label* index_not_number,
 | 
| -                        Label* index_out_of_range,
 | 
| -                        StringIndexFlags index_flags)
 | 
| -      : char_code_at_generator_(object,
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| -                                index,
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| -                                scratch1,
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| -                                scratch2,
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| -                                receiver_not_string,
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| -                                index_not_number,
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| -                                index_out_of_range,
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| -                                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 internal
 | 
| -}  // namespace v8
 | 
| -
 | 
|  #endif  // V8_CODEGEN_H_
 | 
| 
 |