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//===========================================================================

//

//      s_ceil.c

//

//      Part of the standard mathematical function library

//

//===========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos is free software; you can redistribute it and/or modify it under

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// for more details.

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//

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// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

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//####ECOSGPLCOPYRIGHTEND####

//===========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):   jlarmour

// Contributors:  jlarmour

// Date:        1998-02-13

// Purpose:     

// Description: 

// Usage:       

//

//####DESCRIPTIONEND####

//

//===========================================================================

// CONFIGURATION

#include <pkgconf/libm.h>   // Configuration header

// Include the Math library?

#ifdef CYGPKG_LIBM     

// Derived from code with the following copyright

/* @(#)s_ceil.c 1.3 95/01/18 */

/*

 * ====================================================

 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.

 *

 * Developed at SunSoft, a Sun Microsystems, Inc. business.

 * Permission to use, copy, modify, and distribute this

 * software is freely granted, provided that this notice

 * is preserved.

 * ====================================================

 */

/*

 * ceil(x)

 * Return x rounded toward +inf to integral value

 * Method:

 *      Bit twiddling.

 * Exception:

 *      Inexact flag raised if x not equal to ceil(x).

 */

#include "mathincl/fdlibm.h"

static const double huge = 1.0e300;

        double ceil(double x)

{

        int i0,i1,j0;

        unsigned i,j;

        i0 =  CYG_LIBM_HI(x);

        i1 =  CYG_LIBM_LO(x);

        j0 = ((i0>>20)&0x7ff)-0x3ff;

        if(j0<20) {

            if(j0<0) {  /* raise inexact if x != 0 */

                if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */

                    if(i0<0) {i0=0x80000000;i1=0;}

                    else if((i0|i1)!=0) { i0=0x3ff00000;i1=0;}

                }

            } else {

                i = (0x000fffff)>>j0;

                if(((i0&i)|i1)==0) return x; /* x is integral */

                if(huge+x>0.0) {        /* raise inexact flag */

                    if(i0>0) i0 += (0x00100000)>>j0;

                    i0 &= (~i); i1=0;

                }

            }

        } else if (j0>51) {

            if(j0==0x400) return x+x;   /* inf or NaN */

            else return x;              /* x is integral */

        } else {

            i = ((unsigned)(0xffffffff))>>(j0-20);

            if((i1&i)==0) return x;     /* x is integral */

            if(huge+x>0.0) {            /* raise inexact flag */

                if(i0>0) {

                    if(j0==20) i0+=1;

                    else {

                        j = i1 + (1<<(52-j0));

                        if(j<(unsigned)i1) i0+=1;       /* got a carry */

                        i1 = j;

                    }

                }

                i1 &= (~i);

            }

        }

        CYG_LIBM_HI(x) = i0;

        CYG_LIBM_LO(x) = i1;

        return x;

}

#endif // ifdef CYGPKG_LIBM     

// EOF s_ceil.c