sl@0: // Copyright (c) 1995-2009 Nokia Corporation and/or its subsidiary(-ies).
sl@0: // All rights reserved.
sl@0: // This component and the accompanying materials are made available
sl@0: // under the terms of the License "Eclipse Public License v1.0"
sl@0: // which accompanies this distribution, and is available
sl@0: // at the URL "http://www.eclipse.org/legal/epl-v10.html".
sl@0: //
sl@0: // Initial Contributors:
sl@0: // Nokia Corporation - initial contribution.
sl@0: //
sl@0: // Contributors:
sl@0: //
sl@0: // Description:
sl@0: // e32\euser\maths\um_utl.cpp
sl@0: // 
sl@0: //
sl@0: 
sl@0: #include "um_std.h"
sl@0: 
sl@0: #if defined(__USE_VFP_MATH) && !defined(__CPU_HAS_VFP)
sl@0: #error	__USE_VFP_MATH was defined but not __CPU_HAS_VFP - impossible combination, check variant.mmh 
sl@0: #endif
sl@0: 
sl@0: GLDEF_C void Panic(TMathPanic aPanic)
sl@0: //
sl@0: // Panic the process with USER-Math as the category.
sl@0: //
sl@0: 	{
sl@0: 
sl@0: 	User::Panic(_L("USER-Math"),aPanic);
sl@0: 	}
sl@0: 
sl@0: 
sl@0: 
sl@0: #ifdef __USE_VFP_MATH
sl@0: extern "C" void __set_errno(TInt errno)
sl@0: 	{
sl@0: 	// Do nothing, we don't have an errno to set as we use
sl@0: 	// return values instead - return values are recosntructed
sl@0: 	// from the results/inputs, not from this
sl@0: 	}
sl@0: 
sl@0: extern "C" IMPORT_C TReal __ARM_scalbn(TReal,TInt);
sl@0: extern "C" TReal scalbn(TReal x,TInt n)
sl@0: 	{
sl@0: 	return __ARM_scalbn(x,n);
sl@0: 	}
sl@0: #endif
sl@0: 
sl@0: 
sl@0: 
sl@0: #ifndef __REALS_MACHINE_CODED__
sl@0: EXPORT_C TReal Math::Poly(TReal aX,const SPoly *aPoly)
sl@0: /**
sl@0: Evaluates the polynomial:
sl@0: {a[n]X^n + a[n-1]X^(n-1) + ... + a[2]X^2 + a[1]X^1 + a[0]}.
sl@0: 
sl@0: 
sl@0: @param aX    The value of the x-variable 
sl@0: @param aPoly A pointer to the structure containing the set of coefficients
sl@0:              in the order: a[0], a[1], ..., a[n-1], a[n].
sl@0: 
sl@0: @return The result of the evaluation.
sl@0: */
sl@0: //
sl@0: // Evaluate a power series in x for a P_POLY coefficient table.
sl@0: // Changed to use TRealX throughout the calculation
sl@0: //
sl@0: 	{
sl@0: 
sl@0: 	const TReal *pR=(&aPoly->c[aPoly->num-1]);
sl@0: 	TRealX r(*pR);
sl@0: 	TRealX x(aX);
sl@0: 	while (pR>&aPoly->c[0])
sl@0: 		{
sl@0: 		r*=x;
sl@0: 		r+=*--pR;
sl@0: 		}
sl@0: 	return(TReal(r));
sl@0: 	}
sl@0: 
sl@0: 
sl@0: 
sl@0: 
sl@0: EXPORT_C void Math::PolyX(TRealX& aY, const TRealX& aX, TInt aDegree, const TRealX *aCoeff)
sl@0: /**
sl@0: Evaluates the polynomial:
sl@0: {a[n]X^n + a[n-1]X^(n-1) + ... + a[2]X^2 + a[1]X^1 + a[0]}.
sl@0: 
sl@0: @param aY      A reference containing the result. 
sl@0: @param aX      The value of the x-variable. 
sl@0: @param aDegree The degree of the polynomial (the highest power of x
sl@0:                which is present).
sl@0: @param aCoeff  A pointer to a contiguous set of TRealX values containing
sl@0:                the coefficients.
sl@0:                They must be in the order: a[0], a[1], ..., a[n-1], a[n].
sl@0: */
sl@0: 	{
sl@0:     // Evaluate a polynomial with TRealX argument and TRealX coefficients.
sl@0:     // Return a TRealX result.
sl@0: 
sl@0: 	const TRealX *pC=aCoeff+aDegree;
sl@0: 	aY=*pC;
sl@0: 	while(aDegree--)
sl@0: 		{
sl@0: 		aY*=aX;
sl@0: 		aY+=*--pC;
sl@0: 		}
sl@0: 	}
sl@0: #endif