// Copyright (c) 2010-2010 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:

// e32\nkern\nklib.cpp

// 

//

#include <e32atomics.h>

#include <nklib.h>

#ifndef __SRATIO_MACHINE_CODED__

void SRatio::Set(TUint32 aInt, TInt aDivisorExp)

	{

	iSpare1 = 0;

	iSpare2 = 0;

	iM = aInt;

	if (iM)

		{

		TInt ms1 = __e32_find_ms1_32(iM);

		TInt shift = 31 - ms1;

		iM <<= shift;

		iX = (TInt16)(-shift - aDivisorExp);

		}

	else

		iX = 0;

	}

TInt SRatio::Reciprocal()

	{

	if (iM==0)

		return KErrDivideByZero;

	// Calculate 2^32/iM

	TInt exp=0;

	if (iM == 0x80000000u)

		{

		// ratio = 2^(31+iX) so reciprocal = 2^(-31-iX) = 2^(31 + (-62-iX))

		exp = -62-iX;

		}

	else

		{

		// 2^32/iM = 1.xxx

		TUint64 r64 = MAKE_TUINT64(0u-iM,0);

		TUint32 q32 = (TUint32)(r64/TUint64(iM));	// next 32 bits of result

		iM = 0x80000000u | (q32>>1);

		exp = -63-iX;

		if (q32 & 1)

			{

			if (++iM==0)

				iM=0x80000000u, ++exp;

			}

		}

	if (exp < -32768)

		{

		iM = 0;

		iX = 0;

		return KErrUnderflow;

		}

	if (exp > 32767)

		{

		iM = 0xffffffffu;

		iX = 32767;

		return KErrOverflow;

		}

	iX = (TInt16)exp;

	return KErrNone;

	}

TInt SRatio::Mult(TUint32& aInt32)

	{

	TUint64 x = aInt32;

	x *= TUint64(iM);

	if (x==0)

		{

		aInt32 = 0;

		return KErrNone;

		}

	TInt ms1 = __e32_find_ms1_64(x);

	TInt ms1b = ms1 + iX;

	if (ms1b>=32)

		{

		aInt32 = ~0u;

		return KErrOverflow;

		}

	if (ms1b<-1)

		{

		aInt32 = 0;

		return KErrUnderflow;

		}

	TInt shift = ms1b - ms1 + 31;

	if (shift > 0)

		x <<= shift;

	else if (shift < 0)

		x >>= (-shift);

	x += MAKE_TUINT64(0,0x40000000u);

	if (x >> 63)

		{

		aInt32 = ~0u;

		return KErrOverflow;

		}

	aInt32 = (TUint32)(x>>31);

	return aInt32 ? KErrNone : KErrUnderflow;

	}

//TInt SRatio::Mult(TUint64& aInt64)

//	{

//	}

#endif

void SRatioInv::Set(const SRatio* a)

	{

	if (a)

		{

		iR = *a;

		iI = iR;

		iI.Reciprocal();

		}

	else

		{

		iR.Set(1);

		iI.Set(1);

		}

	}