gzdoom/code/M_fixed.c

// Emacs style mode select	 -*- C++ -*- 
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// $Log:$
//
// DESCRIPTION:
//		Fixed point implementation.
//
//-----------------------------------------------------------------------------



#include <stdlib.h>

#include "doomtype.h"
#include "i_system.h"

#include "m_fixed.h"


#ifndef USEASM

// C routines

fixed_t FixedMul_C (fixed_t a, fixed_t b)
{
	return (fixed_t)(((__int64) a * (__int64) b) >> FRACBITS);
}

fixed_t FixedDiv_C (fixed_t a, fixed_t b)
{
	if ((abs (a) >> 14) >= abs (b))
		return (a^b)<0 ? MININT : MAXINT;

	{
#if 0
		long long c;
		c = ((long long)a<<16) / ((long long)b);
		return (fixed_t) c;
#endif

		double c;

		c = ((double)a) / ((double)b) * FRACUNIT;
/*
	    if (c >= 2147483648.0 || c < -2147483648.0)
			I_FatalError("FixedDiv: divide by zero");
*/
		return (fixed_t) c;
	}
}

#endif