text: // Copyright 2014 the V8 project authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef V8_TYPE_CACHE_H_
  #define V8_TYPE_CACHE_H_
  
  #include "src/types.h"
  
  namespace v8 {
  namespace internal {
  
  class TypeCache final {
   private:
    // This has to be first for the initialization magic to work.
    base::AccountingAllocator allocator;
    Zone zone_;
  
   public:
    static TypeCache const& Get();
  
    TypeCache() : zone_(&allocator) {}
  
    Type* const kInt8 =
        CreateNative(CreateRange<int8_t>(), Type::UntaggedIntegral8());
    Type* const kUint8 =
        CreateNative(CreateRange<uint8_t>(), Type::UntaggedIntegral8());
    Type* const kUint8Clamped = kUint8;
    Type* const kInt16 =
        CreateNative(CreateRange<int16_t>(), Type::UntaggedIntegral16());
    Type* const kUint16 =
        CreateNative(CreateRange<uint16_t>(), Type::UntaggedIntegral16());
    Type* const kInt32 =
        CreateNative(Type::Signed32(), Type::UntaggedIntegral32());
    Type* const kUint32 =
        CreateNative(Type::Unsigned32(), Type::UntaggedIntegral32());
    Type* const kFloat32 = CreateNative(Type::Number(), Type::UntaggedFloat32());
    Type* const kFloat64 = CreateNative(Type::Number(), Type::UntaggedFloat64());
  
    Type* const kSmi = CreateNative(Type::SignedSmall(), Type::TaggedSigned());
    Type* const kHeapNumber = CreateNative(Type::Number(), Type::TaggedPointer());
  
    Type* const kSingletonZero = CreateRange(0.0, 0.0);
    Type* const kSingletonOne = CreateRange(1.0, 1.0);
    Type* const kSingletonMinusOne = CreateRange(-1.0, -1.0);
    Type* const kMinusOneOrZero = CreateRange(-1.0, 0.0);
    Type* const kZeroOrOne = CreateRange(0.0, 1.0);
    Type* const kZeroToThirtyOne = CreateRange(0.0, 31.0);
    Type* const kZeroToThirtyTwo = CreateRange(0.0, 32.0);
    Type* const kZeroish =
        Type::Union(kSingletonZero, Type::MinusZeroOrNaN(), zone());
    Type* const kInteger = CreateRange(-V8_INFINITY, V8_INFINITY);
    Type* const kIntegerOrMinusZero =
        Type::Union(kInteger, Type::MinusZero(), zone());
    Type* const kIntegerOrMinusZeroOrNaN =
        Type::Union(kIntegerOrMinusZero, Type::NaN(), zone());
    Type* const kPositiveInteger = CreateRange(0.0, V8_INFINITY);
    Type* const kPositiveIntegerOrMinusZero =
        Type::Union(kPositiveInteger, Type::MinusZero(), zone());
    Type* const kPositiveIntegerOrMinusZeroOrNaN =
        Type::Union(kPositiveIntegerOrMinusZero, Type::NaN(), zone());
  
    Type* const kAdditiveSafeInteger =
        CreateRange(-4503599627370496.0, 4503599627370496.0);
    Type* const kSafeInteger = CreateRange(-kMaxSafeInteger, kMaxSafeInteger);
    Type* const kAdditiveSafeIntegerOrMinusZero =
        Type::Union(kAdditiveSafeInteger, Type::MinusZero(), zone());
    Type* const kSafeIntegerOrMinusZero =
        Type::Union(kSafeInteger, Type::MinusZero(), zone());
    Type* const kPositiveSafeInteger = CreateRange(0.0, kMaxSafeInteger);
    Type* const kSafeSigned32 = CreateRange(-kMaxInt, kMaxInt);
  
    Type* const kUntaggedUndefined =
        Type::Intersect(Type::Undefined(), Type::Untagged(), zone());
    Type* const kSigned32OrMinusZero =
        Type::Union(Type::Signed32(), Type::MinusZero(), zone());
  
    // Asm.js related types.
    Type* const kAsmSigned = kInt32;
    Type* const kAsmUnsigned = kUint32;
    Type* const kAsmInt = Type::Union(kAsmSigned, kAsmUnsigned, zone());
    Type* const kAsmFixnum = Type::Intersect(kAsmSigned, kAsmUnsigned, zone());
    Type* const kAsmFloat = kFloat32;
    Type* const kAsmDouble = kFloat64;
    Type* const kAsmFloatQ = Type::Union(kAsmFloat, kUntaggedUndefined, zone());
    Type* const kAsmDoubleQ = Type::Union(kAsmDouble, kUntaggedUndefined, zone());
    // Not part of the Asm.js type hierarchy, but represents a part of what
    // intish encompasses.
    Type* const kAsmIntQ = Type::Union(kAsmInt, kUntaggedUndefined, zone());
    Type* const kAsmFloatDoubleQ = Type::Union(kAsmFloatQ, kAsmDoubleQ, zone());
    // Asm.js size unions.
    Type* const kAsmSize8 = Type::Union(kInt8, kUint8, zone());
    Type* const kAsmSize16 = Type::Union(kInt16, kUint16, zone());
    Type* const kAsmSize32 =
        Type::Union(Type::Union(kInt32, kUint32, zone()), kAsmFloat, zone());
    Type* const kAsmSize64 = kFloat64;
    // Asm.js other types.
    Type* const kAsmComparable = Type::Union(
        kAsmSigned,
        Type::Union(kAsmUnsigned, Type::Union(kAsmDouble, kAsmFloat, zone()),
                    zone()),
        zone());
    Type* const kAsmIntArrayElement =
        Type::Union(Type::Union(kInt8, kUint8, zone()),
                    Type::Union(Type::Union(kInt16, kUint16, zone()),
                                Type::Union(kInt32, kUint32, zone()), zone()),
                    zone());
  
    // The FixedArray::length property always containts a smi in the range
    // [0, FixedArray::kMaxLength].
    Type* const kFixedArrayLengthType = CreateNative(
        CreateRange(0.0, FixedArray::kMaxLength), Type::TaggedSigned());
  
    // The FixedDoubleArray::length property always containts a smi in the range
    // [0, FixedDoubleArray::kMaxLength].
    Type* const kFixedDoubleArrayLengthType = CreateNative(
        CreateRange(0.0, FixedDoubleArray::kMaxLength), Type::TaggedSigned());
  
    // The JSArray::length property always contains a tagged number in the range
    // [0, kMaxUInt32].
    Type* const kJSArrayLengthType =
        CreateNative(Type::Unsigned32(), Type::Tagged());
  
    // The String::length property always contains a smi in the range
    // [0, String::kMaxLength].
    Type* const kStringLengthType =
        CreateNative(CreateRange(0.0, String::kMaxLength), Type::TaggedSigned());
  
  #define TYPED_ARRAY(TypeName, type_name, TYPE_NAME, ctype, size) \
    Type* const k##TypeName##Array = CreateArray(k##TypeName);
    TYPED_ARRAYS(TYPED_ARRAY)
  #undef TYPED_ARRAY
  
   private:
    Type* CreateArray(Type* element) { return Type::Array(element, zone()); }
  
    Type* CreateArrayFunction(Type* array) {
      Type* arg1 = Type::Union(Type::Unsigned32(), Type::Object(), zone());
      Type* arg2 = Type::Union(Type::Unsigned32(), Type::Undefined(), zone());
      Type* arg3 = arg2;
      return Type::Function(array, arg1, arg2, arg3, zone());
    }
  
    Type* CreateNative(Type* semantic, Type* representation) {
      return Type::Intersect(semantic, representation, zone());
    }
  
    template <typename T>
    Type* CreateRange() {
      return CreateRange(std::numeric_limits<T>::min(),
                         std::numeric_limits<T>::max());
    }
  
    Type* CreateRange(double min, double max) {
      return Type::Range(min, max, zone());
    }
  
    Zone* zone() { return &zone_; }
  };
  
  }  // namespace internal
  }  // namespace v8
  
  #endif  // V8_TYPE_CACHE_H_
  