/*========================================================================
//
//      double/portable-api/s_ceil.c
//
//      Part of the standard mathematical function library
//
//========================================================================
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// -------------------------------------------                              
// This file is part of eCos, the Embedded Configurable Operating System.   
// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2004 Free Software Foundation, Inc.
// Copyright (C) 2004 eCosCentric Limited                                   
//
// eCos is free software; you can redistribute it and/or modify it under    
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// version.                                                                 
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// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.            
//
// As a special exception, if other files instantiate templates or use      
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// and link it with other works to produce a work based on this file,       
// this file does not by itself cause the resulting work to be covered by   
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// must still be made available in accordance with section (3) of the GNU   
// General Public License v2.                                               
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// on this file might be covered by the GNU General Public License.         
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//========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):     jlarmour
// Contributors:  
// Date:          2004-02-30
// Purpose:       
// Description:   Derived from newlib libm
//                http://sources.redhat.com/newlib
//                in turn based on SunSoft fdlibm.
//                See copyright/license information below.
// Usage:         #include <math.h>
//
//####DESCRIPTIONEND####
//======================================================================*/


/* @(#)s_ceil.c 5.1 93/09/24 */
/*
 * ====================================================
 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
 *
 * Developed at SunPro, 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"

#ifndef _DOUBLE_IS_32BITS

#ifdef __STDC__
static const double huge = 1.0e300;
#else
static double huge = 1.0e300;
#endif

#ifdef __STDC__
	double ceil(double x)
#else
	double ceil(x)
	double x;
#endif
{
	__int32_t i0,i1,j0;
	__uint32_t i,j;
	EXTRACT_WORDS(i0,i1,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 = ((__uint32_t)(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<i1) i0+=1;	/* got a carry */
			i1 = j;
		    }
		}
		i1 &= (~i);
	    }
	}
	INSERT_WORDS(x,i0,i1);
	return x;
}

#endif /* _DOUBLE_IS_32BITS */

// EOF s_ceil.c
