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#ifndef QV4ISEL_UTIL_P_H
#define QV4ISEL_UTIL_P_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include "private/qv4value_p.h"
#include "qv4jsir_p.h"

QT_BEGIN_NAMESPACE

namespace QV4 {

struct TargetPrimitive32 {
    static TargetPrimitive32 emptyValue() { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Empty) << 32; return p; }
    static TargetPrimitive32 nullValue() { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Null) << 32; return p; }
    static TargetPrimitive32 undefinedValue() { TargetPrimitive32 p; p._val = quint64(Value::Managed_Type_Internal_32) << 32; return p; }
    static TargetPrimitive32 fromBoolean(bool b) { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Boolean) << 32 | quint64(b); return p; }
    static TargetPrimitive32 fromInt32(int v) { TargetPrimitive32 p; p._val = quint64(Value::ValueTypeInternal_32::Integer) << 32 | quint32(v); return p; }
    static TargetPrimitive32 fromDouble(double v) {
        TargetPrimitive32 p;
        memcpy(&p._val, &v, 8);
        return p;
    }
    static TargetPrimitive32 fromUInt32(uint v) {
        if (v < INT_MAX)
            return fromInt32(qint32(v));
        return fromDouble(double(v));
    }

    quint32 value() const { return _val & quint64(~quint32(0)); }
    quint32 tag() const { return _val >> 32; }

    quint64 rawValue() const { return _val; }

private:
    quint64 _val;
};

struct TargetPrimitive64 {
    static TargetPrimitive64 emptyValue() { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Empty) << 32; return p; }
    static TargetPrimitive64 nullValue() { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Null) << 32; return p; }
    static TargetPrimitive64 undefinedValue() { TargetPrimitive64 p; p._val = 0; return p; }
    static TargetPrimitive64 fromBoolean(bool b) { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Boolean) << 32 | quint64(b); return p; }
    static TargetPrimitive64 fromInt32(int v) { TargetPrimitive64 p; p._val = quint64(Value::ValueTypeInternal_64::Integer) << 32 | quint32(v); return p; }
    static TargetPrimitive64 fromDouble(double v) {
        TargetPrimitive64 p;
        memcpy(&p._val, &v, 8);
        p._val ^= Value::NaNEncodeMask;
        return p;
    }
    static TargetPrimitive64 fromUInt32(uint v) {
        if (v < INT_MAX)
            return fromInt32(qint32(v));
        return fromDouble(double(v));
    }

    quint32 value() const { return _val & quint64(~quint32(0)); }
    quint32 tag() const { return _val >> 32; }

    quint64 rawValue() const { return _val; }

private:
    quint64 _val;
};

inline bool canConvertToSignedInteger(double value)
{
    int ival = (int) value;
    // +0 != -0, so we need to convert to double when negating 0
    return ival == value && !(value == 0 && isNegative(value));
}

inline bool canConvertToUnsignedInteger(double value)
{
    unsigned uval = (unsigned) value;
    // +0 != -0, so we need to convert to double when negating 0
    return uval == value && !(value == 0 && isNegative(value));
}

template <typename PrimitiveType = Primitive>
inline PrimitiveType convertToValue(IR::Const *c)
{
    switch (c->type) {
    case IR::MissingType:
        return PrimitiveType::emptyValue();
    case IR::NullType:
        return PrimitiveType::nullValue();
    case IR::UndefinedType:
        return PrimitiveType::undefinedValue();
    case IR::BoolType:
        return PrimitiveType::fromBoolean(c->value != 0);
    case IR::SInt32Type:
        return PrimitiveType::fromInt32(int(c->value));
    case IR::UInt32Type:
        return PrimitiveType::fromUInt32(unsigned(c->value));
    case IR::DoubleType:
        return PrimitiveType::fromDouble(c->value);
    case IR::NumberType: {
        int ival = (int)c->value;
        if (canConvertToSignedInteger(c->value)) {
            return PrimitiveType::fromInt32(ival);
        } else {
            return PrimitiveType::fromDouble(c->value);
        }
    }
    default:
        Q_UNREACHABLE();
    }
    // unreachable, but the function must return something
    return PrimitiveType::undefinedValue();
}

class ConvertTemps
{
    void renumber(IR::Temp *t)
    {
        if (t->kind != IR::Temp::VirtualRegister)
            return;

        int stackSlot = _stackSlotForTemp.value(t->index, -1);
        if (stackSlot == -1) {
            stackSlot = allocateFreeSlot();
            _stackSlotForTemp[t->index] = stackSlot;
        }

        t->kind = IR::Temp::StackSlot;
        t->index = stackSlot;
    }

protected:
    int _nextUnusedStackSlot;
    QHash<int, int> _stackSlotForTemp;
    IR::BasicBlock *_currentBasicBlock;
    virtual int allocateFreeSlot()
    {
        return _nextUnusedStackSlot++;
    }

    virtual void process(IR::Stmt *s)
    {
        visit(s);
    }

public:
    ConvertTemps()
        : _nextUnusedStackSlot(0)
        , _currentBasicBlock(0)
    {}

    void toStackSlots(IR::Function *function)
    {
        _stackSlotForTemp.reserve(function->tempCount);

        for (IR::BasicBlock *bb : function->basicBlocks()) {
            if (bb->isRemoved())
                continue;
            _currentBasicBlock = bb;
            for (IR::Stmt *s : bb->statements())
                process(s);
        }

        function->tempCount = _nextUnusedStackSlot;
    }

protected:
    void visit(IR::Stmt *s) {
        switch (s->stmtKind) {
        case IR::Stmt::PhiStmt:
            visitPhi(s->asPhi());
            break;
        default:
            STMT_VISIT_ALL_KINDS(s);
            break;
        }
    }

    virtual void visitPhi(IR::Phi *)
    { Q_UNREACHABLE(); }

private:
    void visit(IR::Expr *e) {
        if (auto temp = e->asTemp()) {
            renumber(temp);
        } else {
            EXPR_VISIT_ALL_KINDS(e);
        }
    }
};
} // namespace QV4

QT_END_NAMESPACE

#endif // QV4ISEL_UTIL_P_H