kernel/eka/euser/maths/um_log.cpp
author Mike Kinghan <mikek@symbian.org>
Tue, 16 Nov 2010 14:39:21 +0000
branchGCC_SURGE
changeset 303 9b85206a602c
parent 0 a41df078684a
permissions -rw-r--r--
We need a way to pass flags to rombuilds in Raptor via extension flm interfaces, so that the CPP pass of the rom input files can be informed what toolchain we are building with and conditionally include or exclude files depending on whether the toolchain could build them.

// 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_log.cpp
// Floating point base 10 logarithm
// 
//

#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


#ifndef __USE_VFP_MATH

EXPORT_C TInt Math::Log(TReal &aTrg,const TReal &aSrc)
/**
Calculates the logarithm to base 10 of a number.

@param aTrg  A reference containing the result. 
@param aSrc  The number whose logarithm is required. 
 
@return KErrNone if successful, otherwise another of
        the system-wide error codes. 
*/
//
// Base 10 log routine. See Software manual by W.J.Cody & W.Waite
//
	{

	TInt ret=Math::Ln(aTrg,aSrc);
	if (ret!=KErrNone)
		return(ret);    	
	aTrg*=KRln10;
	return(ret);
	}

#else // __USE_VFP_MATH

// definitions come from RVCT math library
extern "C" TReal log10(TReal);

EXPORT_C TInt Math::Log(TReal& aTrg, const TReal& aSrc)
	{
	aTrg = log10(aSrc);
	if (Math::IsFinite(aTrg))
		return KErrNone;
	if (Math::IsInfinite(aTrg))
		return KErrOverflow;
	SetNaN(aTrg);
	return KErrArgument;
	}

#endif