s_isnanl.c

来自「Glibc 2.3.2源代码(解压后有100多M)」· C语言 代码 · 共 44 行

/* s_isnanl.c -- long double version of s_isnan.c.
 * Conversion to long double by Jakub Jelinek, [e-mail].
 */

/*
 * ====================================================
 * 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

/*
 * isnanl(x) returns 1 is x is nan, else 0;
 * no branching!
 */

#include "math.h"
#include "math_private.h"

#ifdef __STDC__
	int __isnanl(long double x)
#else
	int __isnanl(x)
	long double x;
#endif
{
	int64_t hx,lx;
	GET_LDOUBLE_WORDS64(hx,lx,x);
	hx &= 0x7fffffffffffffffLL;
	hx |= (u_int64_t)(lx|(-lx))>>63;
	hx = 0x7fff000000000000LL - hx;
	return (int)((u_int64_t)hx>>63);
}
hidden_def (__isnanl)
weak_alias (__isnanl, isnanl)