1 /* @(#)s_isnan.c 5.1 93/09/24 */
2 /*
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5 *
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
9 * is preserved.
10 * ====================================================
11 */
12
13 /*
14 * isnan(x) returns 1 is x is nan, else 0;
15 * no branching!
16 */
17
18 #include <math.h>
19 #include <math_private.h>
20 #include <ldbl-classify-compat.h>
21 #include <shlib-compat.h>
22 #include <stdint.h>
23
24 int
__isnan(double x)25 __isnan (double x)
26 {
27 int64_t hx;
28 EXTRACT_WORDS64 (hx, x);
29 hx &= UINT64_C (0x7fffffffffffffff);
30 hx = UINT64_C (0x7ff0000000000000) - hx;
31 return (int)(((uint64_t)hx)>>63);
32 }
33 hidden_def (__isnan)
34 weak_alias (__isnan, isnan)
35 #ifdef NO_LONG_DOUBLE
36 # if LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
37 compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0);
38 # endif
39 weak_alias (__isnan, isnanl)
40 #endif
41