CSE2410 Fall 2014 Bounce

// Copyright 2012 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_TYPE_INFO_H_

#define V8_TYPE_INFO_H_

#include "allocation.h"

#include "globals.h"

#include "types.h"

#include "zone-inl.h"

namespace v8 {

namespace internal {

const int kMaxKeyedPolymorphism = 4;

//         Unknown

//           |   \____________

//           |                |

//      Primitive       Non-primitive

//           |   \_______     |

//           |           |    |

//        Number       String |

//         /   \         |    |

//    Double  Integer32  |   /

//        |      |      /   /

//        |     Smi    /   /

//        |      |    / __/

//        Uninitialized.

class TypeInfo {

 public:

  TypeInfo() : type_(kUninitialized) { }

  static TypeInfo Unknown() { return TypeInfo(kUnknown); }

  // We know it's a primitive type.

  static TypeInfo Primitive() { return TypeInfo(kPrimitive); }

  // We know it's a number of some sort.

  static TypeInfo Number() { return TypeInfo(kNumber); }

  // We know it's a signed 32 bit integer.

  static TypeInfo Integer32() { return TypeInfo(kInteger32); }

  // We know it's a Smi.

  static TypeInfo Smi() { return TypeInfo(kSmi); }

  // We know it's a heap number.

  static TypeInfo Double() { return TypeInfo(kDouble); }

  // We know it's a string.

  static TypeInfo String() { return TypeInfo(kString); }

  // We know it's an internalized string.

  static TypeInfo InternalizedString() { return TypeInfo(kInternalizedString); }

  // We know it's a non-primitive (object) type.

  static TypeInfo NonPrimitive() { return TypeInfo(kNonPrimitive); }

  // We haven't started collecting info yet.

  static TypeInfo Uninitialized() { return TypeInfo(kUninitialized); }

  int ToInt() {

    return type_;

  }

  static TypeInfo FromInt(int bit_representation) {

    Type t = static_cast<Type>(bit_representation);

    ASSERT(t == kUnknown ||

           t == kPrimitive ||

           t == kNumber ||

           t == kInteger32 ||

           t == kSmi ||

           t == kDouble ||

           t == kString ||

           t == kNonPrimitive);

    return TypeInfo(t);

  }

  // Return the weakest (least precise) common type.

  static TypeInfo Combine(TypeInfo a, TypeInfo b) {

    return TypeInfo(static_cast<Type>(a.type_ & b.type_));

  }

  // Integer32 is an integer that can be represented as a signed

  // 32-bit integer. It has to be

  // in the range [-2^31, 2^31 - 1]. We also have to check for negative 0

  // as it is not an Integer32.

  static inline bool IsInt32Double(double value) {

    const DoubleRepresentation minus_zero(-0.0);

    DoubleRepresentation rep(value);

    if (rep.bits == minus_zero.bits) return false;

    if (value >= kMinInt && value <= kMaxInt &&

        value == static_cast<int32_t>(value)) {

      return true;

    }

    return false;

  }

  static TypeInfo FromValue(Handle<Object> value);

  bool Equals(const TypeInfo& other) {

    return type_ == other.type_;

  }

  inline bool IsUnknown() {

    ASSERT(type_ != kUninitialized);

    return type_ == kUnknown;

  }

  inline bool IsPrimitive() {

    ASSERT(type_ != kUninitialized);

    return ((type_ & kPrimitive) == kPrimitive);

  }

  inline bool IsNumber() {

    ASSERT(type_ != kUninitialized);

    return ((type_ & kNumber) == kNumber);

  }

  inline bool IsSmi() {

    ASSERT(type_ != kUninitialized);

    return ((type_ & kSmi) == kSmi);

  }

  inline bool IsInternalizedString() {

    ASSERT(type_ != kUninitialized);

    return ((type_ & kInternalizedString) == kInternalizedString);

  }

  inline bool IsNonInternalizedString() {

    ASSERT(type_ != kUninitialized);

    return ((type_ & kInternalizedString) == kString);

  }

  inline bool IsInteger32() {

    ASSERT(type_ != kUninitialized);

    return ((type_ & kInteger32) == kInteger32);

  }

  inline bool IsDouble() {

    ASSERT(type_ != kUninitialized);

    return ((type_ & kDouble) == kDouble);

  }

  inline bool IsString() {

    ASSERT(type_ != kUninitialized);

    return ((type_ & kString) == kString);

  }

  inline bool IsNonPrimitive() {

    ASSERT(type_ != kUninitialized);

    return ((type_ & kNonPrimitive) == kNonPrimitive);

  }

  inline bool IsUninitialized() {

    return type_ == kUninitialized;

  }

  const char* ToString() {

    switch (type_) {

      case kUnknown: return "Unknown";

      case kPrimitive: return "Primitive";

      case kNumber: return "Number";

      case kInteger32: return "Integer32";

      case kSmi: return "Smi";

      case kInternalizedString: return "InternalizedString";

      case kDouble: return "Double";

      case kString: return "String";

      case kNonPrimitive: return "Object";

      case kUninitialized: return "Uninitialized";

    }

    UNREACHABLE();

    return "Unreachable code";

  }

 private:

  enum Type {

    kUnknown = 0,                // 0000000

    kPrimitive = 0x10,           // 0010000

    kNumber = 0x11,              // 0010001

    kInteger32 = 0x13,           // 0010011

    kSmi = 0x17,                 // 0010111

    kDouble = 0x19,              // 0011001

    kString = 0x30,              // 0110000

    kInternalizedString = 0x32,  // 0110010

    kNonPrimitive = 0x40,        // 1000000

    kUninitialized = 0x7f        // 1111111

  };

  explicit inline TypeInfo(Type t) : type_(t) { }

  Type type_;

};

enum StringStubFeedback {

  DEFAULT_STRING_STUB = 0,

  STRING_INDEX_OUT_OF_BOUNDS = 1

};

// Forward declarations.

// TODO(rossberg): these should all go away eventually.

class Assignment;

class Call;

class CallNew;

class CaseClause;

class CompilationInfo;

class CountOperation;

class Expression;

class ForInStatement;

class ICStub;

class Property;

class SmallMapList;

class ObjectLiteral;

class ObjectLiteralProperty;

class TypeFeedbackOracle: public ZoneObject {

 public:

  TypeFeedbackOracle(Handle<Code> code,

                     Handle<Context> native_context,

                     Isolate* isolate,

                     Zone* zone);

  bool LoadIsMonomorphicNormal(Property* expr);

  bool LoadIsUninitialized(Property* expr);

  bool LoadIsPreMonomorphic(Property* expr);

  bool LoadIsPolymorphic(Property* expr);

  bool StoreIsUninitialized(TypeFeedbackId ast_id);

  bool StoreIsMonomorphicNormal(TypeFeedbackId ast_id);

  bool StoreIsPreMonomorphic(TypeFeedbackId ast_id);

  bool StoreIsKeyedPolymorphic(TypeFeedbackId ast_id);

  bool CallIsMonomorphic(Call* expr);

  bool CallNewIsMonomorphic(CallNew* expr);

  bool ObjectLiteralStoreIsMonomorphic(ObjectLiteralProperty* prop);

  // TODO(1571) We can't use ForInStatement::ForInType as the return value due

  // to various cycles in our headers.

  byte ForInType(ForInStatement* expr);

  Handle<Map> LoadMonomorphicReceiverType(Property* expr);

  Handle<Map> StoreMonomorphicReceiverType(TypeFeedbackId id);

  KeyedAccessStoreMode GetStoreMode(TypeFeedbackId ast_id);

  void LoadReceiverTypes(Property* expr,

                         Handle<String> name,

                         SmallMapList* types);

  void StoreReceiverTypes(Assignment* expr,

                          Handle<String> name,

                          SmallMapList* types);

  void CallReceiverTypes(Call* expr,

                         Handle<String> name,

                         CallKind call_kind,

                         SmallMapList* types);

  void CollectKeyedReceiverTypes(TypeFeedbackId ast_id,

                                 SmallMapList* types);

  void CollectPolymorphicStoreReceiverTypes(TypeFeedbackId ast_id,

                                            SmallMapList* types);

  static bool CanRetainOtherContext(Map* map, Context* native_context);

  static bool CanRetainOtherContext(JSFunction* function,

                                    Context* native_context);

  void CollectPolymorphicMaps(Handle<Code> code, SmallMapList* types);

  CheckType GetCallCheckType(Call* expr);

  Handle<JSFunction> GetCallTarget(Call* expr);

  Handle<JSFunction> GetCallNewTarget(CallNew* expr);

  Handle<Cell> GetCallNewAllocationInfoCell(CallNew* expr);

  Handle<Map> GetObjectLiteralStoreMap(ObjectLiteralProperty* prop);

  bool LoadIsBuiltin(Property* expr, Builtins::Name id);

  bool LoadIsStub(Property* expr, ICStub* stub);

  // TODO(1571) We can't use ToBooleanStub::Types as the return value because

  // of various cycles in our headers. Death to tons of implementations in

  // headers!! :-P

  byte ToBooleanTypes(TypeFeedbackId id);

  // Get type information for arithmetic operations and compares.

  void BinaryType(TypeFeedbackId id,

                  Handle<Type>* left,

                  Handle<Type>* right,

                  Handle<Type>* result,

                  Maybe<int>* fixed_right_arg,

                  Token::Value operation);

  void CompareType(TypeFeedbackId id,

                   Handle<Type>* left,

                   Handle<Type>* right,

                   Handle<Type>* combined);

  Handle<Type> ClauseType(TypeFeedbackId id);

  Handle<Type> IncrementType(CountOperation* expr);

  Zone* zone() const { return zone_; }

  Isolate* isolate() const { return isolate_; }

 private:

  void CollectReceiverTypes(TypeFeedbackId ast_id,

                            Handle<String> name,

                            Code::Flags flags,

                            SmallMapList* types);

  void SetInfo(TypeFeedbackId ast_id, Object* target);

  void BuildDictionary(Handle<Code> code);

  void GetRelocInfos(Handle<Code> code, ZoneList<RelocInfo>* infos);

  void CreateDictionary(Handle<Code> code, ZoneList<RelocInfo>* infos);

  void RelocateRelocInfos(ZoneList<RelocInfo>* infos,

                          byte* old_start,

                          byte* new_start);

  void ProcessRelocInfos(ZoneList<RelocInfo>* infos);

  void ProcessTypeFeedbackCells(Handle<Code> code);

  // Returns an element from the backing store. Returns undefined if

  // there is no information.

  Handle<Object> GetInfo(TypeFeedbackId ast_id);

  // Return the cell that contains type feedback.

  Handle<Cell> GetInfoCell(TypeFeedbackId ast_id);

 private:

  Handle<Context> native_context_;

  Isolate* isolate_;

  Zone* zone_;

  Handle<UnseededNumberDictionary> dictionary_;

  DISALLOW_COPY_AND_ASSIGN(TypeFeedbackOracle);

};

} }  // namespace v8::internal

#endif  // V8_TYPE_INFO_H_