/*
* Copyright (C) 2008 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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.
*/
#pragma once
namespace JSC {
// FIXME: Consider whether this is actually necessary. Is LLInt and Baseline's profiling information enough?
// https://bugs.webkit.org/show_bug.cgi?id=201659
struct ResultType {
private:
friend struct OperandTypes;
using Type = uint8_t;
static constexpr Type TypeInt32 = 0x1 << 0;
static constexpr Type TypeMaybeNumber = 0x1 << 1;
static constexpr Type TypeMaybeString = 0x1 << 2;
static constexpr Type TypeMaybeBigInt = 0x1 << 3;
static constexpr Type TypeMaybeNull = 0x1 << 4;
static constexpr Type TypeMaybeBool = 0x1 << 5;
static constexpr Type TypeMaybeOther = 0x1 << 6;
static constexpr Type TypeBits = TypeMaybeNumber | TypeMaybeString | TypeMaybeBigInt | TypeMaybeNull | TypeMaybeBool | TypeMaybeOther;
public:
static constexpr int numBitsNeeded = 7;
static_assert((TypeBits & ((1 << numBitsNeeded) - 1)) == TypeBits, "This is necessary for correctness.");
constexpr explicit ResultType()
: ResultType(unknownType())
{
}
constexpr explicit ResultType(Type type)
: m_bits(type)
{
}
constexpr bool isInt32() const
{
return m_bits & TypeInt32;
}
constexpr bool definitelyIsNumber() const
{
return (m_bits & TypeBits) == TypeMaybeNumber;
}
constexpr bool definitelyIsString() const
{
return (m_bits & TypeBits) == TypeMaybeString;
}
constexpr bool definitelyIsBoolean() const
{
return (m_bits & TypeBits) == TypeMaybeBool;
}
constexpr bool definitelyIsBigInt() const
{
return (m_bits & TypeBits) == TypeMaybeBigInt;
}
constexpr bool definitelyIsNull() const
{
return (m_bits & TypeBits) == TypeMaybeNull;
}
constexpr bool mightBeUndefinedOrNull() const
{
return m_bits & (TypeMaybeNull | TypeMaybeOther);
}
constexpr bool mightBeNumber() const
{
return m_bits & TypeMaybeNumber;
}
constexpr bool isNotNumber() const
{
return !mightBeNumber();
}
constexpr bool mightBeBigInt() const
{
return m_bits & TypeMaybeBigInt;
}
constexpr bool isNotBigInt() const
{
return !mightBeBigInt();
}
static constexpr ResultType nullType()
{
return ResultType(TypeMaybeNull);
}
static constexpr ResultType booleanType()
{
return ResultType(TypeMaybeBool);
}
static constexpr ResultType numberType()
{
return ResultType(TypeMaybeNumber);
}
static constexpr ResultType numberTypeIsInt32()
{
return ResultType(TypeInt32 | TypeMaybeNumber);
}
static constexpr ResultType stringOrNumberType()
{
return ResultType(TypeMaybeNumber | TypeMaybeString);
}
static constexpr ResultType addResultType()
{
return ResultType(TypeMaybeNumber | TypeMaybeString | TypeMaybeBigInt);
}
static constexpr ResultType stringType()
{
return ResultType(TypeMaybeString);
}
static constexpr ResultType bigIntType()
{
return ResultType(TypeMaybeBigInt);
}
static constexpr ResultType bigIntOrInt32Type()
{
return ResultType(TypeMaybeBigInt | TypeInt32 | TypeMaybeNumber);
}
static constexpr ResultType bigIntOrNumberType()
{
return ResultType(TypeMaybeBigInt | TypeMaybeNumber);
}
static constexpr ResultType unknownType()
{
return ResultType(TypeBits);
}
static constexpr ResultType forAdd(ResultType op1, ResultType op2)
{
if (op1.definitelyIsNumber() && op2.definitelyIsNumber())
return numberType();
if (op1.definitelyIsString() || op2.definitelyIsString())
return stringType();
if (op1.definitelyIsBigInt() && op2.definitelyIsBigInt())
return bigIntType();
return addResultType();
}
static constexpr ResultType forNonAddArith(ResultType op1, ResultType op2)
{
if (op1.definitelyIsNumber() && op2.definitelyIsNumber())
return numberType();
if (op1.definitelyIsBigInt() && op2.definitelyIsBigInt())
return bigIntType();
return bigIntOrNumberType();
}
static constexpr ResultType forUnaryArith(ResultType op)
{
if (op.definitelyIsNumber())
return numberType();
if (op.definitelyIsBigInt())
return bigIntType();
return bigIntOrNumberType();
}
// Unlike in C, a logical op produces the value of the
// last expression evaluated (and not true or false).
static constexpr ResultType forLogicalOp(ResultType op1, ResultType op2)
{
if (op1.definitelyIsBoolean() && op2.definitelyIsBoolean())
return booleanType();
if (op1.definitelyIsNumber() && op2.definitelyIsNumber())
return numberType();
if (op1.definitelyIsString() && op2.definitelyIsString())
return stringType();
if (op1.definitelyIsBigInt() && op2.definitelyIsBigInt())
return bigIntType();
return unknownType();
}
static constexpr ResultType forCoalesce(ResultType op1, ResultType op2)
{
if (op1.definitelyIsNull())
return op2;
if (!op1.mightBeUndefinedOrNull())
return op1;
return unknownType();
}
static constexpr ResultType forBitOp()
{
return bigIntOrInt32Type();
}
constexpr Type bits() const { return m_bits; }
void dump(PrintStream& out) const
{
// FIXME: more meaningful information
// https://bugs.webkit.org/show_bug.cgi?id=190930
out.print(bits());
}
private:
Type m_bits;
};
struct OperandTypes
{
OperandTypes(ResultType first = ResultType::unknownType(), ResultType second = ResultType::unknownType())
{
m_first = first.m_bits;
m_second = second.m_bits;
}
ResultType::Type m_first;
ResultType::Type m_second;
ResultType first() const
{
return ResultType(m_first);
}
ResultType second() const
{
return ResultType(m_second);
}
uint16_t bits()
{
static_assert(sizeof(OperandTypes) == sizeof(uint16_t));
return bitwise_cast