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/* s_nextafterl.c -- long double version of s_nextafter.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
/* IEEE functions
* nextafterl(x,y)
* return the next machine floating-point number of x in the
* direction toward y.
* Special cases:
*/
#include <math.h>
#include <math_private.h>
#include <math_ldbl_opt.h>
long double __nextafterl(long double x, long double y)
{
int64_t hx,hy,ihx,ihy;
uint64_t lx;
double xhi, xlo, yhi;
ldbl_unpack (x, &xhi, &xlo);
EXTRACT_WORDS64 (hx, xhi);
EXTRACT_WORDS64 (lx, xlo);
yhi = ldbl_high (y);
EXTRACT_WORDS64 (hy, yhi);
ihx = hx&0x7fffffffffffffffLL; /* |hx| */
ihy = hy&0x7fffffffffffffffLL; /* |hy| */
if((ihx>0x7ff0000000000000LL) || /* x is nan */
(ihy>0x7ff0000000000000LL)) /* y is nan */
return x+y; /* signal the nan */
if(x==y)
return y; /* x=y, return y */
if(ihx == 0) { /* x == 0 */
long double u; /* return +-minsubnormal */
hy = (hy & 0x8000000000000000ULL) | 1;
INSERT_WORDS64 (yhi, hy);
x = yhi;
u = math_opt_barrier (x);
u = u * u;
math_force_eval (u); /* raise underflow flag */
return x;
}
long double u;
if(x > y) { /* x > y, x -= ulp */
/* This isn't the largest magnitude correctly rounded
long double as you can see from the lowest mantissa
bit being zero. It is however the largest magnitude
long double with a 106 bit mantissa, and nextafterl
is insane with variable precision. So to make
nextafterl sane we assume 106 bit precision. */
if((hx==0xffefffffffffffffLL)&&(lx==0xfc8ffffffffffffeLL))
return x+x; /* overflow, return -inf */
if (hx >= 0x7ff0000000000000LL) {
u = 0x1.fffffffffffff7ffffffffffff8p+1023L;
return u;
}
if(ihx <= 0x0360000000000000LL) { /* x <= LDBL_MIN */
u = math_opt_barrier (x);
x -= __LDBL_DENORM_MIN__;
if (ihx < 0x0360000000000000LL
|| (hx > 0 && (int64_t) lx <= 0)
|| (hx < 0 && (int64_t) lx > 1)) {
u = u * u;
math_force_eval (u); /* raise underflow flag */
}
return x;
}
if (ihx < 0x06a0000000000000LL) { /* ulp will denormal */
INSERT_WORDS64 (yhi, hx & (0x7ffLL<<52));
u = yhi;
u *= 0x1.0000000000000p-105L;
} else {
INSERT_WORDS64 (yhi, (hx & (0x7ffLL<<52))-(0x069LL<<52));
u = yhi;
}
return x - u;
} else { /* x < y, x += ulp */
if((hx==0x7fefffffffffffffLL)&&(lx==0x7c8ffffffffffffeLL))
return x+x; /* overflow, return +inf */
if ((uint64_t) hx >= 0xfff0000000000000ULL) {
u = -0x1.fffffffffffff7ffffffffffff8p+1023L;
return u;
}
if(ihx <= 0x0360000000000000LL) { /* x <= LDBL_MIN */
u = math_opt_barrier (x);
x += __LDBL_DENORM_MIN__;
if (ihx < 0x0360000000000000LL
|| (hx > 0 && (int64_t) lx < 0 && lx != 0x8000000000000001LL)
|| (hx < 0 && (int64_t) lx >= 0)) {
u = u * u;
math_force_eval (u); /* raise underflow flag */
}
if (x == 0.0L) /* handle negative __LDBL_DENORM_MIN__ case */
x = -0.0L;
return x;
}
if (ihx < 0x06a0000000000000LL) { /* ulp will denormal */
INSERT_WORDS64 (yhi, hx & (0x7ffLL<<52));
u = yhi;
u *= 0x1.0000000000000p-105L;
} else {
INSERT_WORDS64 (yhi, (hx & (0x7ffLL<<52))-(0x069LL<<52));
u = yhi;
}
return x + u;
}
}
strong_alias (__nextafterl, __nexttowardl)
long_double_symbol (libm, __nextafterl, nextafterl);
long_double_symbol (libm, __nexttowardl, nexttowardl);
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