// Copyright (c) 1995-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of the License "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

// e32test\math\largeint.cpp

// 

//

#include "largeint.h"

TLargeIntBase::TLargeIntBase(TInt n)

	: iC(n)

	{

	Mem::FillZ(iX,n*sizeof(TUint32));

	}

TLargeIntBase::TLargeIntBase(TInt n, TInt32 aSigned32)

	: iC(n)

	{

	TUint f = (aSigned32<0) ? 0xff : 0;

	Mem::Fill(iX,n*sizeof(TUint32),f);

	iX[0]=aSigned32;

	}

TLargeIntBase::TLargeIntBase(TInt n, TUint32 aUnsigned32)

	: iC(n)

	{

	Mem::FillZ(iX,n*sizeof(TUint32));

	iX[0]=aUnsigned32;

	}

TLargeIntBase::TLargeIntBase(TInt n, const TLargeIntBase& aSrc, TMode aMode)

	: iC(n)

	{

	__ASSERT(aMode==ETruncate||n>=aSrc.iC);	// if not truncating, dest can't be shorter than source

	__ASSERT(aMode!=ETruncate||n<=aSrc.iC);	// if truncating, dest can't be longer than source

	TInt min = Min(n,aSrc.iC);

	TInt i;

	for (i=0; i<min; ++i)

		iX[i] = aSrc.iX[i];

	if (aMode==ETruncate || n==aSrc.iC)

		return;

	TUint32 f = (aMode==ESignExtend && (iX[i-1] & 0x80000000u)) ? 0xffffffffu : 0;

	for (; i<n; ++i)

		iX[i] = f;

	}

TLargeIntBase::TLargeIntBase(TInt n, const TUint32* aPtr)

	: iC(n)

	{

	Mem::Copy(iX, aPtr, n*sizeof(TUint32));

	}

TLargeIntBase::TLargeIntBase(TInt n, const Int64& aSigned64)

	: iC(n)

	{

	__ASSERT(n>=2);

	Mem::Copy(iX, &aSigned64, 8);

	TUint f = (iX[1] & 0x80000000u) ? 0xff : 0;

	Mem::Fill(iX+2,(n-2)*sizeof(TUint32),f);

	}

TLargeIntBase::TLargeIntBase(TInt n, const Uint64& aUnsigned64)

	: iC(n)

	{

	__ASSERT(n>=2);

	Mem::Copy(iX, &aUnsigned64, 8);

	Mem::FillZ(iX+2,(n-2)*sizeof(TUint32));

	}

void TLargeIntBase::Not()

	{

	TInt i;

	for (i=0; i<iC; ++i)

		iX[i] = ~iX[i];

	}

void TLargeIntBase::Neg()

	{

	Not();

	Inc();

	}

void TLargeIntBase::Abs()

	{

	if (iX[iC-1] & 0x80000000u)

		Neg();

	}

void TLargeIntBase::Inc()

	{

	TInt i;

	for (i=0; i<iC && ++iX[i]==0; ++i) {}

	}

void TLargeIntBase::Dec()

	{

	TInt i;

	for (i=0; i<iC && --iX[i]==0xffffffffu; ++i) {}

	}

TUint32 TLargeIntBase::Lsl()

	{

	TInt i;

	TUint32 c = 0;

	for (i=0; i<iC; ++i)

		{

		TUint32 x = (iX[i]<<1) | (c>>31);

		c = iX[i];

		iX[i] = x;

		}

	return c>>31;

	}

TUint32 TLargeIntBase::Lsr()

	{

	TInt i;

	TUint32 c = 0;

	for (i=iC-1; i>=0; --i)

		{

		TUint32 x = (iX[i]>>1) | (c<<31);

		c = iX[i];

		iX[i] = x;

		}

	return c&1;

	}

TUint32 TLargeIntBase::Asr()

	{

	TInt i=iC-1;

	TUint32 c = iX[i]>>31;

	for (; i>=0; --i)

		{

		TUint32 x = (iX[i]>>1) | (c<<31);

		c = iX[i];

		iX[i] = x;

		}

	return c&1;

	}

void TLargeIntBase::Lsl(TInt aCount)

	{

	while(--aCount>=0)

		Lsl();

	}

void TLargeIntBase::Lsr(TInt aCount)

	{

	while(--aCount>=0)

		Lsr();

	}

void TLargeIntBase::Asr(TInt aCount)

	{

	while(--aCount>=0)

		Asr();

	}

void TLargeIntBase::Add(const TLargeIntBase& a)

	{

	__ASSERT(a.iC==iC);

	TInt i;

	TUint32 c = 0;

	for (i=0; i<iC; ++i)

		{

		TUint32 x = iX[i];

		TUint32 y = a.iX[i];

		TUint32 s = x + y;

		iX[i] = (s + (c>>31));

		TUint32 g = (x & y) | ((x | y) &~ s);

		TUint32 p = ~s ? 0 : s;

		c = g | (c & p);

		}

	}

void TLargeIntBase::Sub(const TLargeIntBase& a)

	{

	__ASSERT(a.iC==iC);

	TInt i;

	TUint32 c = 0x80000000u;

	for (i=0; i<iC; ++i)

		{

		TUint32 x = iX[i];

		TUint32 y = ~a.iX[i];

		TUint32 s = x + y;

		iX[i] = (s + (c>>31));

		TUint32 g = (x & y) | ((x | y) &~ s);

		TUint32 p = ~s ? 0 : s;

		c = g | (c & p);

		}

	}

void TLargeIntBase::Mul(const TLargeIntBase& a)

	{

	__ASSERT(a.iC==iC);

	TUint32 temp[64];	// HACK!!

	Mem::Copy(temp, this, (iC+1)*sizeof(TUint32));

	TLargeIntBase& b = *(TLargeIntBase*)temp;

	new (this) TLargeIntBase(iC,TUint32(0u));

	TInt i;

	for (i=0; i<32*iC; ++i)

		{

		Lsl();

		if (b.Lsl())

			Add(a);

		}

	}

void TLargeIntBase::DivU(const TLargeIntBase& aDivisor, TLargeIntBase& aRem)

	{

	__ASSERT(aDivisor.iC==iC);

	__ASSERT(aRem.iC==iC);

	new (&aRem) TLargeIntBase(iC,TUint32(0u));

	TInt i;

	for (i=0; i<iC*32; ++i)

		{

		aRem.Lsl();

		if (Lsl())

			aRem.Inc();

		if (aRem.Hs(aDivisor))

			aRem.Sub(aDivisor), Inc();

		}

	}

void TLargeIntBase::DivS(const TLargeIntBase& aDivisor, TLargeIntBase& aRem)

	{

	__ASSERT(aDivisor.iC==iC);

	__ASSERT(aRem.iC==iC);

	TUint32 temp[64];	// HACK!!

	Mem::Copy(temp, &aDivisor, (iC+1)*sizeof(TUint32));

	TLargeIntBase& divisor = *(TLargeIntBase*)temp;

	TUint32 rs = iX[iC-1];

	TUint32 qs = divisor.iX[iC-1] ^ rs;

	Abs();

	divisor.Abs();

	DivU(divisor, aRem);

	if (rs & 0x80000000u)

		aRem.Neg();

	if (qs & 0x80000000u)

		Neg();

	}

TInt TLargeIntBase::CompareU(const TLargeIntBase& a) const

	{

	__ASSERT(a.iC==iC);

	TInt i;

	for (i=iC-1; i>=0; --i)

		{

		TUint32 x = iX[i];

		TUint32 y = a.iX[i];

		if (x>y)

			return 1;

		if (x<y)

			return -1;

		}

	return 0;

	}

TInt TLargeIntBase::CompareS(const TLargeIntBase& a) const

	{

	__ASSERT(a.iC==iC);

	TInt i;

	TUint32 m = 0x80000000u;

	for (i=iC-1; i>=0; --i)

		{

		TUint32 x = iX[i] ^ m;

		TUint32 y = a.iX[i] ^ m;

		m = 0;

		if (x>y)

			return 1;

		if (x<y)

			return -1;

		}

	return 0;

	}