xref: /haiku/src/system/libroot/posix/glibc/arch/x86/s_isinfl.c (revision 1d9d47fc72028bb71b5f232a877231e59cfe2438)
1 /*
2  * Written by J.T. Conklin <jtc@netbsd.org>.
3  * Change for long double by Ulrich Drepper <drepper@cygnus.com>.
4  * Intel i387 specific version.
5  * Public domain.
6  */
7 
8 #if defined(LIBM_SCCS) && !defined(lint)
9 static char rcsid[] = "$NetBSD: $";
10 #endif
11 
12 /*
13  * isinfl(x) returns 1 if x is inf, -1 if x is -inf, else 0;
14  * no branching!
15  */
16 
17 #include "math.h"
18 #include "math_private.h"
19 
20 #ifdef __STDC__
21 	int __isinfl(long double x)
22 #else
23 	int __isinfl(x)
24 	long double x;
25 #endif
26 {
27 	int32_t se,hx,lx;
28 	GET_LDOUBLE_WORDS(se,hx,lx,x);
29 	/* This additional ^ 0x80000000 is necessary because in Intel's
30 	   internal representation of the implicit one is explicit.  */
31 	lx |= (hx ^ 0x80000000) | ((se & 0x7fff) ^ 0x7fff);
32 	lx |= -lx;
33 	se &= 0x8000;
34 	return ~(lx >> 31) & (1 - (se >> 14));
35 }
36 hidden_def (__isinfl)
37 weak_alias (__isinfl, isinfl)
38