idiv.h

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// ============================================================================
// Project:     Deductive Database
// Filename:    idiv.h
// Purpose:     Macros for rounded integer division and percent
// Last Change: 04.08.2017
// Language:    C++
// EMail:       brass@informatik.uni-halle.de
// WWW:         http://www.informatik.uni-halle.de/~brass/
// Address:     Feldschloesschen 15, D-06120 Halle (Saale), GERMANY
// Copyright:   (c) 2015-2017 by Stefan Brass
// License:     See file "LICENSE" for copying conditions.
// Note:        There is no warranty at all - this code may contain bugs.
// ============================================================================


//=============================================================================
// Include File Frame:
//=============================================================================

#ifndef IDIV_INCLUDED
#define IDIV_INCLUDED


//=============================================================================
// Used Types and Macros:
//=============================================================================

#ifndef VER_INCLUDED
#include "../base/ver.h"
#endif

#ifndef CHECK_INCLUDED
#include "../base/check.h"
#endif


//=============================================================================
// Defined Types and Macros:
//=============================================================================

// Note that all macros work only for non-negative numbers.
// For negative numbers, C and C++ do not completely prescribe the result
// of integer division. It would be more complicated to get a portable result.

//-----------------------------------------------------------------------------
// IDIV_ROUND:
//-----------------------------------------------------------------------------

#define IDIV_ROUND(X,Y) (((X)+(Y)/2)/(Y))

//-----------------------------------------------------------------------------
// IDIV_CEILING:
//-----------------------------------------------------------------------------

#define IDIV_CEILING(X,Y)       (((X)+(Y)-1)/(Y))

//-----------------------------------------------------------------------------
// IDIV_WHOLE:
//-----------------------------------------------------------------------------

#define IDIV_WHOLE(X,Y) ((((X)*10+(Y)/2)/(Y))/10)

//-----------------------------------------------------------------------------
// IDIV_TENTH:
//-----------------------------------------------------------------------------

//#define IDIV_TENTH(X,Y)       ((((X)*10+(Y)/2)/(Y))%10)
#define IDIV_TENTH(X,Y) (((((X)-IDIV_WHOLE((X),(Y))*(Y)) * 10 + (Y)/2)) / (Y))
        // In this way, we do not have to multiply X by 10,
        // which is important if X is large (near the integer limit).

//-----------------------------------------------------------------------------
// IDIV_PERCENT:
//-----------------------------------------------------------------------------

#define IDIV_PERCENT(X,Y)       (((X)*100+((Y)/2))/(Y))


//=============================================================================
// End of Include File:
//=============================================================================

#endif