1/*
2 * Written by J.T. Conklin <jtc@netbsd.org>.
3 * Changed to return -1 for -Inf by Ulrich Drepper <drepper@cygnus.com>.
4 * Public domain.
5 */
6
7/*
8 * isinf(x) returns 1 is x is inf, -1 if x is -inf, else 0;
9 * no branching!
10 */
11
12#include <math.h>
13#include <math_private.h>
14#include <ldbl-classify-compat.h>
15#include <shlib-compat.h>
16
17int
18__isinf (double x)
19{
20 int64_t ix;
21 EXTRACT_WORDS64 (ix,x);
22 int64_t t = ix & UINT64_C (0x7fffffffffffffff);
23 t ^= UINT64_C (0x7ff0000000000000);
24 t |= -t;
25 return ~(t >> 63) & (ix >> 62);
26}
27hidden_def (__isinf)
28weak_alias (__isinf, isinf)
29#ifdef NO_LONG_DOUBLE
30# if LDBL_CLASSIFY_COMPAT && SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_23)
31compat_symbol (libc, __isinf, __isinfl, GLIBC_2_0);
32# endif
33weak_alias (__isinf, isinfl)
34#endif
35