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/* s_frexpl.c -- long double version of s_frexp.c.
* 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>
#include <math_ldbl_opt.h>
static const long double
two107 = 162259276829213363391578010288128.0; /* 0x4670000000000000, 0 */
long double __frexpl(long double x, int *eptr)
{
uint64_t hx, lx, ix, ixl;
int64_t explo;
double xhi, xlo;
ldbl_unpack (x, &xhi, &xlo);
EXTRACT_WORDS64 (hx, xhi);
EXTRACT_WORDS64 (lx, xlo);
ixl = 0x7fffffffffffffffULL&lx;
ix = 0x7fffffffffffffffULL&hx;
*eptr = 0;
if(ix>=0x7ff0000000000000ULL||ix==0) return x; /* 0,inf,nan */
if (ix<0x0010000000000000ULL) { /* subnormal */
x *= two107;
xhi = ldbl_high (x);
EXTRACT_WORDS64 (hx, xhi);
ix = hx&0x7fffffffffffffffULL;
*eptr = -107;
}
*eptr += (ix>>52)-1022;
if (ixl != 0ULL) {
explo = (ixl>>52) - (ix>>52) + 0x3fe;
if ((ixl&0x7ff0000000000000ULL) == 0LL) {
/* the lower double is a denormal so we need to correct its
mantissa and perhaps its exponent. */
int cnt;
if (sizeof (ixl) == sizeof (long))
cnt = __builtin_clzl (ixl);
else if ((ixl >> 32) != 0)
cnt = __builtin_clzl ((long) (ixl >> 32));
else
cnt = __builtin_clzl ((long) ixl) + 32;
cnt = cnt - 12;
lx = (lx&0x8000000000000000ULL) | ((explo-cnt)<<52)
| ((ixl<<(cnt+1))&0x000fffffffffffffULL);
} else
lx = (lx&0x800fffffffffffffULL) | (explo<<52);
} else
lx = 0ULL;
hx = (hx&0x800fffffffffffffULL) | 0x3fe0000000000000ULL;
INSERT_WORDS64 (xhi, hx);
INSERT_WORDS64 (xlo, lx);
x = ldbl_pack (xhi, xlo);
return x;
}
#ifdef IS_IN_libm
long_double_symbol (libm, __frexpl, frexpl);
#else
long_double_symbol (libc, __frexpl, frexpl);
#endif
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