/*							ceill()
 *							floorl()
 *							frexpl()
 *							ldexpl()
 *							fabsl()
 *
 *	Floating point numeric utilities
 *
 *
 *
 * SYNOPSIS:
 *
 * long double x, y;
 * long double ceill(), floorl(), frexpl(), ldexpl(), fabsl();
 * int expnt, n;
 *
 * y = floorl(x);
 * y = ceill(x);
 * y = frexpl( x, &expnt );
 * y = ldexpl( x, n );
 * y = fabsl( x );
 *
 *
 *
 * DESCRIPTION:
 *
 * All four routines return a long double precision floating point
 * result.
 *
 * floorl() returns the largest integer less than or equal to x.
 * It truncates toward minus infinity.
 *
 * ceill() returns the smallest integer greater than or equal
 * to x.  It truncates toward plus infinity.
 *
 * frexpl() extracts the exponent from x.  It returns an integer
 * power of two to expnt and the significand between 0.5 and 1
 * to y.  Thus  x = y * 2**expn.
 *
 * ldexpl() multiplies x by 2**n.
 *
 * fabsl() returns the absolute value of its argument.
 *
 * These functions are part of the standard C run time library
 * for some but not all C compilers.  The ones supplied are
 * written in C for IEEE arithmetic.  They should
 * be used only if your compiler library does not already have
 * them.
 *
 * The IEEE versions assume that denormal numbers are implemented
 * in the arithmetic.  Some modifications will be required if
 * the arithmetic has abrupt rather than gradual underflow.
 */


/*
Cephes Math Library Release 2.2:  July, 1992
Copyright 1984, 1987, 1988, 1992 by Stephen L. Moshier
Direct inquiries to 30 Frost Street, Cambridge, MA 02140
*/


#include "mconf.h"
#define DENORMAL 0

#ifdef UNK
char *unkmsg = "ceill(), floorl(), frexpl(), ldexpl() must be rewritten!\n";
#endif

#ifdef IBMPC
#define EXPMSK 0x800f
#define MEXP 0x7ff
#define NBITS 64
#endif

#ifdef MIEEE
#define EXPMSK 0x800f
#define MEXP 0x7ff
#define NBITS 64
#endif

extern double MAXNUML;


long double fabsl(x)
long double x;
{
if( x < 0 )
	return( -x );
else
	return( x );
}



long double ceill(x)
long double x;
{
long double y;
long double floorl();

#ifdef UNK
mtherr( "ceill", DOMAIN );
return(0.0L);
#endif

y = floorl(x);
if( y < x )
	y += 1.0L;
return(y);
}




/* Bit clearing masks: */

static unsigned short bmask[] = {
0xffff,
0xfffe,
0xfffc,
0xfff8,
0xfff0,
0xffe0,
0xffc0,
0xff80,
0xff00,
0xfe00,
0xfc00,
0xf800,
0xf000,
0xe000,
0xc000,
0x8000,
0x0000,
};




long double floorl(x)
long double x;
{
unsigned short *p;
long double y;
int e, i;

#ifdef UNK
mtherr( "floor", DOMAIN );
return(0.0L);
#endif

y = x;
/* find the exponent (power of 2) */
#ifdef IBMPC
p = (unsigned short *)&y + 4;
e = (*p & 0x7fff) - 0x3fff;
p -= 4;
#endif

#ifdef MIEEE
p = (unsigned short *)&y;
e = (*p & 0x7fff) - 0x3fff;
p += 5;
#endif

if( e < 0 )
	{
	if( y < 0.0L )
		return( -1.0L );
	else
		return( 0.0L );
	}

e = (NBITS -1) - e;
/* clean out 16 bits at a time */
while( e >= 16 )
	{
#ifdef IBMPC
	*p++ = 0;
#endif

#ifdef MIEEE
	*p-- = 0;
#endif
	e -= 16;
	}

/* clear the remaining bits */
if( e > 0 )
	*p &= bmask[e];

if( (x < 0) && (y != x) )
	y -= 1.0L;

return(y);
}



long double frexpl( x, pw2 )
long double x;
int *pw2;
{
long double y;
int i, k;
short *q;

y = x;

#ifdef UNK
mtherr( "frexp", DOMAIN );
return(0.0L);
#endif

/* find the exponent (power of 2) */
#ifdef IBMPC
q = (short *)&y + 4;
i  = *q & 0x7fff;
#endif

#ifdef MIEEE
q = (short *)&y;
i  = *q & 0x7fff;
#endif


if( i == 0 )
	{
	if( y == 0.0L )
		{
		*pw2 = 0;
		return(0.0L);
		}
/* Number is denormal or zero */
#if DENORMAL
/* Handle denormal number. */
do
	{
	y *= 2.0L;
	i -= 1;
	k  = *q & 0x7fff;
	}
while( (k == 0) && (i > -66) );
i = i + k;
#else
	*pw2 = 0;
	return(0.0L);
#endif /* DENORMAL */
	}

*pw2 = i - 0x3ffe;
*q = 0x3ffe;
return( y );
}






long double ldexpl( x, pw2 )
long double x;
int pw2;
{
long double y;
unsigned short *q;
long e;

#ifdef UNK
mtherr( "ldexp", DOMAIN );
return(0.0L);
#endif

y = x;
#ifdef IBMPC
q = (unsigned short *)&y + 4;
#endif
#ifdef MIEEE
q = (unsigned short *)&y;
#endif
while( (e = (*q & 0x7fffL)) == 0 )
	{
#if DENORMAL
	if( y == 0.0L )
		{
		return( 0.0L );
		}
/* Input is denormal. */
	if( pw2 > 0 )
		{
		y *= 2.0L;
		pw2 -= 1;
		}
	if( pw2 < 0 )
		{
		if( pw2 < -64 )
			return(0.0L);
		y *= 0.5;
		pw2 += 1;
		}
	if( pw2 == 0 )
		return(y);
#else
	return( 0.0L );
#endif
	}

e = e + pw2;

/* Handle overflow */
if( e > 0x7fffL )
	{
	return( MAXNUML );
	}
*q &= 0x8000;
/* Handle denormalized results */
if( e < 1 )
	{
#if DENORMAL
	if( e < -64 )
		return(0.0L);

#ifdef IBMPC
	*(q-1) |= 0x8000;
#endif
#ifdef MIEEE
	*(q+2) |= 0x8000;
#endif

	while( e < 1 )
		{
		y *= 0.5;
		e += 1;
		}
	e = 0;
#else
	return(0.0L);
#endif
	}

*q |= e & 0x7fff;
return(y);
}