path: root/Source/JavaScriptCore/bytecode/SpeculatedType.h

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#ifndef SpeculatedType_h
#define SpeculatedType_h

#include "JSValue.h"

namespace JSC {

class Structure;

typedef uint32_t SpeculatedType;
static const SpeculatedType SpecNone              = 0x00000000; // We don't know anything yet.
static const SpeculatedType SpecFinalObject       = 0x00000001; // It's definitely a JSFinalObject.
static const SpeculatedType SpecArray             = 0x00000002; // It's definitely a JSArray.
static const SpeculatedType SpecFunction          = 0x00000008; // It's definitely a JSFunction or one of its subclasses.
static const SpeculatedType SpecInt8Array         = 0x00000010; // It's definitely an Int8Array or one of its subclasses.
static const SpeculatedType SpecInt16Array        = 0x00000020; // It's definitely an Int16Array or one of its subclasses.
static const SpeculatedType SpecInt32Array        = 0x00000040; // It's definitely an Int32Array or one of its subclasses.
static const SpeculatedType SpecUint8Array        = 0x00000080; // It's definitely an Uint8Array or one of its subclasses.
static const SpeculatedType SpecUint8ClampedArray = 0x00000100; // It's definitely an Uint8ClampedArray or one of its subclasses.
static const SpeculatedType SpecUint16Array       = 0x00000200; // It's definitely an Uint16Array or one of its subclasses.
static const SpeculatedType SpecUint32Array       = 0x00000400; // It's definitely an Uint32Array or one of its subclasses.
static const SpeculatedType SpecFloat32Array      = 0x00000800; // It's definitely an Uint16Array or one of its subclasses.
static const SpeculatedType SpecFloat64Array      = 0x00001000; // It's definitely an Uint16Array or one of its subclasses.
static const SpeculatedType SpecMyArguments       = 0x00002000; // It's definitely an Arguments object, and it's definitely the one for my current frame.
static const SpeculatedType SpecForeignArguments  = 0x00004000; // It's definitely an Arguments object, and it's definitely not mine.
static const SpeculatedType SpecArguments         = 0x00006000; // It's definitely an Arguments object.
static const SpeculatedType SpecObjectOther       = 0x00008000; // It's definitely an object but not JSFinalObject, JSArray, or JSFunction.
static const SpeculatedType SpecObjectMask        = 0x0000ffff; // Bitmask used for testing for any kind of object prediction.
static const SpeculatedType SpecString            = 0x00010000; // It's definitely a JSString.
static const SpeculatedType SpecCellOther         = 0x00020000; // It's definitely a JSCell but not a subclass of JSObject and definitely not a JSString.
static const SpeculatedType SpecCell              = 0x0003ffff; // It's definitely a JSCell.
static const SpeculatedType SpecInt32             = 0x00800000; // It's definitely an Int32.
static const SpeculatedType SpecDoubleReal        = 0x01000000; // It's definitely a non-NaN double.
static const SpeculatedType SpecDoubleNaN         = 0x02000000; // It's definitely a NaN.
static const SpeculatedType SpecDouble            = 0x03000000; // It's either a non-NaN or a NaN double.
static const SpeculatedType SpecNumber            = 0x03800000; // It's either an Int32 or a Double.
static const SpeculatedType SpecBoolean           = 0x04000000; // It's definitely a Boolean.
static const SpeculatedType SpecOther             = 0x08000000; // It's definitely none of the above.
static const SpeculatedType SpecTop               = 0x0fffffff; // It can be any of the above.
static const SpeculatedType SpecEmpty             = 0x10000000; // It's definitely an empty value marker.
static const SpeculatedType SpecEmptyOrTop        = 0x1fffffff; // It can be any of the above.
static const SpeculatedType FixedIndexedStorageMask    = SpecInt8Array | SpecInt16Array | SpecInt32Array | SpecUint8Array | SpecUint8ClampedArray | SpecUint16Array | SpecUint32Array | SpecFloat32Array | SpecFloat64Array;

typedef bool (*SpeculatedTypeChecker)(SpeculatedType);

// Dummy prediction checker, only useful if someone insists on requiring a prediction checker.
inline bool isAnySpeculation(SpeculatedType)
{
    return true;
}

inline bool isCellSpeculation(SpeculatedType value)
{
    return !!(value & SpecCell) && !(value & ~SpecCell);
}

inline bool isObjectSpeculation(SpeculatedType value)
{
    return !!(value & SpecObjectMask) && !(value & ~SpecObjectMask);
}

inline bool isFinalObjectSpeculation(SpeculatedType value)
{
    return value == SpecFinalObject;
}

inline bool isFinalObjectOrOtherSpeculation(SpeculatedType value)
{
    return !!(value & (SpecFinalObject | SpecOther)) && !(value & ~(SpecFinalObject | SpecOther));
}

inline bool isFixedIndexedStorageObjectSpeculation(SpeculatedType value)
{
    return !!value && (value & FixedIndexedStorageMask) == value;
}

inline bool isStringSpeculation(SpeculatedType value)
{
    return value == SpecString;
}

inline bool isArraySpeculation(SpeculatedType value)
{
    return value == SpecArray;
}

inline bool isFunctionSpeculation(SpeculatedType value)
{
    return value == SpecFunction;
}

inline bool isInt8ArraySpeculation(SpeculatedType value)
{
    return value == SpecInt8Array;
}

inline bool isInt16ArraySpeculation(SpeculatedType value)
{
    return value == SpecInt16Array;
}

inline bool isInt32ArraySpeculation(SpeculatedType value)
{
    return value == SpecInt32Array;
}

inline bool isUint8ArraySpeculation(SpeculatedType value)
{
    return value == SpecUint8Array;
}

inline bool isUint8ClampedArraySpeculation(SpeculatedType value)
{
    return value == SpecUint8ClampedArray;
}

inline bool isUint16ArraySpeculation(SpeculatedType value)
{
    return value == SpecUint16Array;
}

inline bool isUint32ArraySpeculation(SpeculatedType value)
{
    return value == SpecUint32Array;
}

inline bool isFloat32ArraySpeculation(SpeculatedType value)
{
    return value == SpecFloat32Array;
}

inline bool isFloat64ArraySpeculation(SpeculatedType value)
{
    return value == SpecFloat64Array;
}

inline bool isArgumentsSpeculation(SpeculatedType value)
{
    return !!value && (value & SpecArguments) == value;
}

inline bool isActionableIntMutableArraySpeculation(SpeculatedType value)
{
    return isInt8ArraySpeculation(value)
        || isInt16ArraySpeculation(value)
        || isInt32ArraySpeculation(value)
        || isUint8ArraySpeculation(value)
        || isUint8ClampedArraySpeculation(value)
        || isUint16ArraySpeculation(value)
        || isUint32ArraySpeculation(value);
}

inline bool isActionableFloatMutableArraySpeculation(SpeculatedType value)
{
    return isFloat32ArraySpeculation(value)
        || isFloat64ArraySpeculation(value);
}

inline bool isActionableTypedMutableArraySpeculation(SpeculatedType value)
{
    return isActionableIntMutableArraySpeculation(value)
        || isActionableFloatMutableArraySpeculation(value);
}

inline bool isActionableMutableArraySpeculation(SpeculatedType value)
{
    return isArraySpeculation(value)
        || isArgumentsSpeculation(value)
        || isActionableTypedMutableArraySpeculation(value);
}

inline bool isActionableArraySpeculation(SpeculatedType value)
{
    return isStringSpeculation(value)
        || isActionableMutableArraySpeculation(value);
}

inline bool isArrayOrOtherSpeculation(SpeculatedType value)
{
    return !!(value & (SpecArray | SpecOther)) && !(value & ~(SpecArray | SpecOther));
}

inline bool isMyArgumentsSpeculation(SpeculatedType value)
{
    return value == SpecMyArguments;
}

inline bool isInt32Speculation(SpeculatedType value)
{
    return value == SpecInt32;
}

inline bool isDoubleRealSpeculation(SpeculatedType value)
{
    return value == SpecDoubleReal;
}

inline bool isDoubleSpeculation(SpeculatedType value)
{
    return !!value && (value & SpecDouble) == value;
}

inline bool isNumberSpeculation(SpeculatedType value)
{
    return !!(value & SpecNumber) && !(value & ~SpecNumber);
}

inline bool isBooleanSpeculation(SpeculatedType value)
{
    return value == SpecBoolean;
}

inline bool isOtherSpeculation(SpeculatedType value)
{
    return value == SpecOther;
}

inline bool isEmptySpeculation(SpeculatedType value)
{
    return value == SpecEmpty;
}

const char* speculationToString(SpeculatedType value);
const char* speculationToAbbreviatedString(SpeculatedType value);

// Merge two predictions. Note that currently this just does left | right. It may
// seem tempting to do so directly, but you would be doing so at your own peril,
// since the merging protocol SpeculatedType may change at any time (and has already
// changed several times in its history).
inline SpeculatedType mergeSpeculations(SpeculatedType left, SpeculatedType right)
{
    return left | right;
}

template<typename T>
inline bool mergeSpeculation(T& left, SpeculatedType right)
{
    SpeculatedType newSpeculation = static_cast<T>(mergeSpeculations(static_cast<SpeculatedType>(left), right));
    bool result = newSpeculation != static_cast<SpeculatedType>(left);
    left = newSpeculation;
    return result;
}

SpeculatedType speculationFromClassInfo(const ClassInfo*);
SpeculatedType speculationFromStructure(Structure*);
SpeculatedType speculationFromCell(JSCell*);
SpeculatedType speculationFromValue(JSValue);

} // namespace JSC

#endif // SpeculatedType_h