SpeculatedType.h   [plain text]

/*
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 *
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 *     from this software without specific prior written permission.
 *
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#ifndef SpeculatedType_h
#define SpeculatedType_h

#include "JSCJSValue.h"
#include "TypedArrayType.h"
#include <wtf/PrintStream.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           = 0x00000004; // It's definitely a JSFunction.
static const SpeculatedType SpecInt8Array          = 0x00000008; // It's definitely an Int8Array or one of its subclasses.
static const SpeculatedType SpecInt16Array         = 0x00000010; // It's definitely an Int16Array or one of its subclasses.
static const SpeculatedType SpecInt32Array         = 0x00000020; // It's definitely an Int32Array or one of its subclasses.
static const SpeculatedType SpecUint8Array         = 0x00000040; // It's definitely an Uint8Array or one of its subclasses.
static const SpeculatedType SpecUint8ClampedArray  = 0x00000080; // It's definitely an Uint8ClampedArray or one of its subclasses.
static const SpeculatedType SpecUint16Array        = 0x00000100; // It's definitely an Uint16Array or one of its subclasses.
static const SpeculatedType SpecUint32Array        = 0x00000200; // It's definitely an Uint32Array or one of its subclasses.
static const SpeculatedType SpecFloat32Array       = 0x00000400; // It's definitely an Uint16Array or one of its subclasses.
static const SpeculatedType SpecFloat64Array       = 0x00000800; // It's definitely an Uint16Array or one of its subclasses.
static const SpeculatedType SpecTypedArrayView     = SpecInt8Array | SpecInt16Array | SpecInt32Array | SpecUint8Array | SpecUint8ClampedArray | SpecUint16Array | SpecUint32Array | SpecFloat32Array | SpecFloat64Array;
static const SpeculatedType SpecDirectArguments    = 0x00001000; // It's definitely a DirectArguments object.
static const SpeculatedType SpecScopedArguments    = 0x00002000; // It's definitely a ScopedArguments object.
static const SpeculatedType SpecStringObject       = 0x00004000; // It's definitely a StringObject.
static const SpeculatedType SpecObjectOther        = 0x00008000; // It's definitely an object but not JSFinalObject, JSArray, or JSFunction.
static const SpeculatedType SpecObject             = 0x0000ffff; // Bitmask used for testing for any kind of object prediction.
static const SpeculatedType SpecStringIdent        = 0x00010000; // It's definitely a JSString, and it's an identifier.
static const SpeculatedType SpecStringVar          = 0x00020000; // It's definitely a JSString, and it's not an identifier.
static const SpeculatedType SpecString             = 0x00030000; // It's definitely a JSString.
static const SpeculatedType SpecSymbol             = 0x00040000; // It's definitely a Symbol.
static const SpeculatedType SpecCellOther          = 0x00080000; // It's definitely a JSCell but not a subclass of JSObject and definitely not a JSString or a Symbol. FIXME: This shouldn't be part of heap-top or bytecode-top. https://bugs.webkit.org/show_bug.cgi?id=133078
static const SpeculatedType SpecCell               = 0x000fffff; // It's definitely a JSCell.
static const SpeculatedType SpecBoolInt32          = 0x00100000; // It's definitely an Int32 with value 0 or 1.
static const SpeculatedType SpecNonBoolInt32       = 0x00200000; // It's definitely an Int32 with value other than 0 or 1.
static const SpeculatedType SpecInt32              = 0x00300000; // It's definitely an Int32.
static const SpeculatedType SpecInt52              = 0x00400000; // It's definitely an Int52 and we intend it to unbox it.
static const SpeculatedType SpecMachineInt         = 0x00700000; // It's something that we can do machine int arithmetic on.
static const SpeculatedType SpecInt52AsDouble      = 0x00800000; // It's definitely an Int52 and it's inside a double.
static const SpeculatedType SpecInteger            = 0x00f00000; // It's definitely some kind of integer.
static const SpeculatedType SpecNonIntAsDouble     = 0x01000000; // It's definitely not an Int52 but it's a real number and it's a double.
static const SpeculatedType SpecDoubleReal         = 0x01800000; // It's definitely a non-NaN double.
static const SpeculatedType SpecDoublePureNaN      = 0x02000000; // It's definitely a NaN that is sae to tag (i.e. pure).
static const SpeculatedType SpecDoubleImpureNaN    = 0x04000000; // It's definitely a NaN that is unsafe to tag (i.e. impure).
static const SpeculatedType SpecDoubleNaN          = 0x06000000; // It's definitely some kind of NaN.
static const SpeculatedType SpecBytecodeDouble     = 0x03800000; // It's either a non-NaN or a NaN double, but it's definitely not impure NaN.
static const SpeculatedType SpecFullDouble         = 0x07800000; // It's either a non-NaN or a NaN double.
static const SpeculatedType SpecBytecodeRealNumber = 0x01b00000; // It's either an Int32 or a DoubleReal.
static const SpeculatedType SpecFullRealNumber     = 0x01f00000; // It's either an Int32 or a DoubleReal, or a Int52.
static const SpeculatedType SpecBytecodeNumber     = 0x03b00000; // It's either an Int32 or a Double, and the Double cannot be an impure NaN.
static const SpeculatedType SpecFullNumber         = 0x07f00000; // It's either an Int32, Int52, or a Double, and the Double can be impure NaN.
static const SpeculatedType SpecBoolean            = 0x10000000; // It's definitely a Boolean.
static const SpeculatedType SpecOther              = 0x20000000; // It's definitely either Null or Undefined.
static const SpeculatedType SpecMisc               = 0x30000000; // It's definitely either a boolean, Null, or Undefined.
static const SpeculatedType SpecHeapTop            = 0x3bbfffff; // It can be any of the above, except for SpecInt52.
static const SpeculatedType SpecEmpty              = 0x40000000; // It's definitely an empty value marker.
static const SpeculatedType SpecBytecodeTop        = 0x7bbfffff; // It can be any of the above, except for SpecInt52.
static const SpeculatedType SpecFullTop            = 0x7fffffff; // It can be any of the above plus anything the DFG chooses.

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 isNotCellSpeculation(SpeculatedType value)
{
    return !(value & SpecCell) && value;
}

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

inline bool isObjectOrOtherSpeculation(SpeculatedType value)
{
    return !!(value & (SpecObject | SpecOther)) && !(value & ~(SpecObject | SpecOther));
}

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

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

inline bool isStringIdentSpeculation(SpeculatedType value)
{
    return value == SpecStringIdent;
}

inline bool isNotStringVarSpeculation(SpeculatedType value)
{
    return !(value & SpecStringVar);
}

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

inline bool isSymbolSpeculation(SpeculatedType value)
{
    return value == SpecSymbol;
}

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 isDirectArgumentsSpeculation(SpeculatedType value)
{
    return value == SpecDirectArguments;
}

inline bool isScopedArgumentsSpeculation(SpeculatedType value)
{
    return value == SpecScopedArguments;
}

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)
        || isActionableTypedMutableArraySpeculation(value);
}

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

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

inline bool isStringObjectSpeculation(SpeculatedType value)
{
    return value == SpecStringObject;
}

inline bool isStringOrStringObjectSpeculation(SpeculatedType value)
{
    return !!value && !(value & ~(SpecString | SpecStringObject));
}

inline bool isBoolInt32Speculation(SpeculatedType value)
{
    return value == SpecBoolInt32;
}

inline bool isInt32Speculation(SpeculatedType value)
{
    return value && !(value & ~SpecInt32);
}

inline bool isInt32OrBooleanSpeculation(SpeculatedType value)
{
    return value && !(value & ~(SpecBoolean | SpecInt32));
}

inline bool isInt32SpeculationForArithmetic(SpeculatedType value)
{
    return !(value & (SpecFullDouble | SpecInt52));
}

inline bool isInt32OrBooleanSpeculationForArithmetic(SpeculatedType value)
{
    return !(value & (SpecFullDouble | SpecInt52));
}

inline bool isInt32OrBooleanSpeculationExpectingDefined(SpeculatedType value)
{
    return isInt32OrBooleanSpeculation(value & ~SpecOther);
}

inline bool isInt52Speculation(SpeculatedType value)
{
    return value == SpecInt52;
}

inline bool isMachineIntSpeculation(SpeculatedType value)
{
    return !!value && (value & SpecMachineInt) == value;
}

inline bool isInt52AsDoubleSpeculation(SpeculatedType value)
{
    return value == SpecInt52AsDouble;
}

inline bool isIntegerSpeculation(SpeculatedType value)
{
    return !!value && (value & SpecInteger) == value;
}

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

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

inline bool isDoubleSpeculationForArithmetic(SpeculatedType value)
{
    return !!(value & SpecFullDouble);
}

inline bool isBytecodeRealNumberSpeculation(SpeculatedType value)
{
    return !!(value & SpecBytecodeRealNumber) && !(value & ~SpecBytecodeRealNumber);
}

inline bool isFullRealNumberSpeculation(SpeculatedType value)
{
    return !!(value & SpecFullRealNumber) && !(value & ~SpecFullRealNumber);
}

inline bool isBytecodeNumberSpeculation(SpeculatedType value)
{
    return !!(value & SpecBytecodeNumber) && !(value & ~SpecBytecodeNumber);
}

inline bool isFullNumberSpeculation(SpeculatedType value)
{
    return !!(value & SpecFullNumber) && !(value & ~SpecFullNumber);
}

inline bool isFullNumberOrBooleanSpeculation(SpeculatedType value)
{
    return value && !(value & ~(SpecFullNumber | SpecBoolean));
}

inline bool isFullNumberOrBooleanSpeculationExpectingDefined(SpeculatedType value)
{
    return isFullNumberOrBooleanSpeculation(value & ~SpecOther);
}

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

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

inline bool isMiscSpeculation(SpeculatedType value)
{
    return !!value && !(value & ~SpecMisc);
}

inline bool isOtherOrEmptySpeculation(SpeculatedType value)
{
    return !value || value == SpecOther;
}

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

void dumpSpeculation(PrintStream&, SpeculatedType);
void dumpSpeculationAbbreviated(PrintStream&, SpeculatedType);

MAKE_PRINT_ADAPTOR(SpeculationDump, SpeculatedType, dumpSpeculation);
MAKE_PRINT_ADAPTOR(AbbreviatedSpeculationDump, SpeculatedType, dumpSpeculationAbbreviated);

// 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;
}

inline bool speculationChecked(SpeculatedType actual, SpeculatedType desired)
{
    return (actual | desired) == desired;
}

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

SpeculatedType speculationFromTypedArrayType(TypedArrayType); // only valid for typed views.
TypedArrayType typedArrayTypeFromSpeculation(SpeculatedType);

SpeculatedType leastUpperBoundOfStrictlyEquivalentSpeculations(SpeculatedType);

bool valuesCouldBeEqual(SpeculatedType, SpeculatedType);

// Precise computation of the type of the result of a double computation after we
// already know that the inputs are doubles and that the result must be a double. Use
// the closest one of these that applies.
SpeculatedType typeOfDoubleSum(SpeculatedType, SpeculatedType);
SpeculatedType typeOfDoubleDifference(SpeculatedType, SpeculatedType);
SpeculatedType typeOfDoubleProduct(SpeculatedType, SpeculatedType);
SpeculatedType typeOfDoubleQuotient(SpeculatedType, SpeculatedType);
SpeculatedType typeOfDoubleMinMax(SpeculatedType, SpeculatedType);
SpeculatedType typeOfDoubleNegation(SpeculatedType);
SpeculatedType typeOfDoubleAbs(SpeculatedType);
SpeculatedType typeOfDoubleRounding(SpeculatedType);
SpeculatedType typeOfDoublePow(SpeculatedType, SpeculatedType);

// This conservatively models the behavior of arbitrary double operations.
SpeculatedType typeOfDoubleBinaryOp(SpeculatedType, SpeculatedType);
SpeculatedType typeOfDoubleUnaryOp(SpeculatedType);

} // namespace JSC

#endif // SpeculatedType_h