diff options
Diffstat (limited to 'sysdeps/libm-ieee754/s_isnan.c')
| -rw-r--r-- | sysdeps/libm-ieee754/s_isnan.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_isnan.c b/sysdeps/libm-ieee754/s_isnan.c new file mode 100644 index 0000000000..2609a51968 --- /dev/null +++ b/sysdeps/libm-ieee754/s_isnan.c @@ -0,0 +1,39 @@ +/* @(#)s_isnan.c 5.1 93/09/24 */ +/* + * ==================================================== + * 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: s_isnan.c,v 1.8 1995/05/10 20:47:36 jtc Exp $"; +#endif + +/* + * isnan(x) returns 1 is x is nan, else 0; + * no branching! + */ + +#include "math.h" +#include "math_private.h" + +#ifdef __STDC__ + int __isnan(double x) +#else + int __isnan(x) + double x; +#endif +{ + int32_t hx,lx; + EXTRACT_WORDS(hx,lx,x); + hx &= 0x7fffffff; + hx |= (u_int32_t)(lx|(-lx))>>31; + hx = 0x7ff00000 - hx; + return (int)((u_int32_t)(hx))>>31; +} +weak_alias (__isnan, isnan) |