glibc/sysdeps/ieee754/ldbl-128/s_frexpl.c

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/* s_frexpl.c -- long double version of s_frexp.c.
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* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
*/
/*
* ====================================================
* 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.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: $";
#endif
/*
* for non-zero x
* x = frexpl(arg,&exp);
* return a long double fp quantity x such that 0.5 <= |x| <1.0
* and the corresponding binary exponent "exp". That is
* arg = x*2^exp.
* If arg is inf, 0.0, or NaN, then frexpl(arg,&exp) returns arg
* with *exp=0.
*/
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
static const long double
#else
static long double
#endif
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two114 = 2.0769187434139310514121985316880384E+34L; /* 0x4071000000000000, 0 */
#ifdef __STDC__
long double __frexpl(long double x, int *eptr)
#else
long double __frexpl(x, eptr)
long double x; int *eptr;
#endif
{
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u_int64_t hx, lx, ix;
GET_LDOUBLE_WORDS64(hx,lx,x);
ix = 0x7fffffffffffffffULL&hx;
*eptr = 0;
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if(ix>=0x7fff000000000000ULL||((ix|lx)==0)) return x; /* 0,inf,nan */
if (ix<0x0001000000000000ULL) { /* subnormal */
x *= two114;
GET_LDOUBLE_MSW64(hx,x);
ix = hx&0x7fffffffffffffffULL;
*eptr = -114;
}
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*eptr += (ix>>48)-16382;
hx = (hx&0x8000ffffffffffffULL) | 0x3ffe000000000000ULL;
SET_LDOUBLE_MSW64(x,hx);
return x;
}
weak_alias (__frexpl, frexpl)