// 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:

// e32\euser\maths\um_utl.cpp

// 

//

#include "um_std.h"

#if defined(__USE_VFP_MATH) && !defined(__CPU_HAS_VFP)

#error	__USE_VFP_MATH was defined but not __CPU_HAS_VFP - impossible combination, check variant.mmh 

#endif

GLDEF_C void Panic(TMathPanic aPanic)

//

// Panic the process with USER-Math as the category.

//

	{

	User::Panic(_L("USER-Math"),aPanic);

	}

#ifdef __USE_VFP_MATH

extern "C" void __set_errno(TInt errno)

	{

	// Do nothing, we don't have an errno to set as we use

	// return values instead - return values are recosntructed

	// from the results/inputs, not from this

	}

extern "C" IMPORT_C TReal __ARM_scalbn(TReal,TInt);

extern "C" TReal scalbn(TReal x,TInt n)

	{

	return __ARM_scalbn(x,n);

	}

#endif

#ifndef __REALS_MACHINE_CODED__

EXPORT_C TReal Math::Poly(TReal aX,const SPoly *aPoly)

/**

Evaluates the polynomial:

{a[n]X^n + a[n-1]X^(n-1) + ... + a[2]X^2 + a[1]X^1 + a[0]}.

@param aX    The value of the x-variable 

@param aPoly A pointer to the structure containing the set of coefficients

             in the order: a[0], a[1], ..., a[n-1], a[n].

@return The result of the evaluation.

*/

//

// Evaluate a power series in x for a P_POLY coefficient table.

// Changed to use TRealX throughout the calculation

//

	{

	const TReal *pR=(&aPoly->c[aPoly->num-1]);

	TRealX r(*pR);

	TRealX x(aX);

	while (pR>&aPoly->c[0])

		{

		r*=x;

		r+=*--pR;

		}

	return(TReal(r));

	}

EXPORT_C void Math::PolyX(TRealX& aY, const TRealX& aX, TInt aDegree, const TRealX *aCoeff)

/**

Evaluates the polynomial:

{a[n]X^n + a[n-1]X^(n-1) + ... + a[2]X^2 + a[1]X^1 + a[0]}.

@param aY      A reference containing the result. 

@param aX      The value of the x-variable. 

@param aDegree The degree of the polynomial (the highest power of x

               which is present).

@param aCoeff  A pointer to a contiguous set of TRealX values containing

               the coefficients.

               They must be in the order: a[0], a[1], ..., a[n-1], a[n].

*/

	{

    // Evaluate a polynomial with TRealX argument and TRealX coefficients.

    // Return a TRealX result.

	const TRealX *pC=aCoeff+aDegree;

	aY=*pC;

	while(aDegree--)

		{

		aY*=aX;

		aY+=*--pC;

		}

	}

#endif