src/number-info.h

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#ifndef V8_NUMBER_INFO_H_
#define V8_NUMBER_INFO_H_

namespace v8 {
namespace internal {

class NumberInfo : public AllStatic {
 public:
  enum Type {
    kUnknown = 0,
    kNumber = 1,
    kSmi = 3,
    kHeapNumber = 5,
    kUninitialized = 7
  };

  // Return the weakest (least precise) common type.
  static Type Combine(Type a, Type b) {
    // Make use of the order of enum values.
    return static_cast<Type>(a & b);
  }

  static bool IsNumber(Type a) {
    ASSERT(a != kUninitialized);
    return ((a & kNumber) != 0);
  }

  static const char* ToString(Type a) {
    switch (a) {
      case kUnknown: return "UnknownType";
      case kNumber: return "NumberType";
      case kSmi: return "SmiType";
      case kHeapNumber: return "HeapNumberType";
      case kUninitialized:
        UNREACHABLE();
        return "UninitializedType";
    }
    UNREACHABLE();
    return "Unreachable code";
  }
};

} }  // namespace v8::internal

#endif  // V8_NUMBER_INFO_H_