// 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