xref: /haiku/src/system/libroot/posix/glibc/arch/x86/s_isinfl.c (revision 901f399036a25e35a7931af6209a327c21dd4dcf)
1*901f3990SIngo Weinhold /*
2*901f3990SIngo Weinhold  * Written by J.T. Conklin <jtc@netbsd.org>.
3*901f3990SIngo Weinhold  * Change for long double by Ulrich Drepper <drepper@cygnus.com>.
4*901f3990SIngo Weinhold  * Intel i387 specific version.
5*901f3990SIngo Weinhold  * Public domain.
6*901f3990SIngo Weinhold  */
7*901f3990SIngo Weinhold 
8*901f3990SIngo Weinhold #if defined(LIBM_SCCS) && !defined(lint)
9*901f3990SIngo Weinhold static char rcsid[] = "$NetBSD: $";
10*901f3990SIngo Weinhold #endif
11*901f3990SIngo Weinhold 
12*901f3990SIngo Weinhold /*
13*901f3990SIngo Weinhold  * isinfl(x) returns 1 if x is inf, -1 if x is -inf, else 0;
14*901f3990SIngo Weinhold  * no branching!
15*901f3990SIngo Weinhold  */
16*901f3990SIngo Weinhold 
17*901f3990SIngo Weinhold #include "math.h"
18*901f3990SIngo Weinhold #include "math_private.h"
19*901f3990SIngo Weinhold 
20*901f3990SIngo Weinhold #ifdef __STDC__
__isinfl(long double x)21*901f3990SIngo Weinhold 	int __isinfl(long double x)
22*901f3990SIngo Weinhold #else
23*901f3990SIngo Weinhold 	int __isinfl(x)
24*901f3990SIngo Weinhold 	long double x;
25*901f3990SIngo Weinhold #endif
26*901f3990SIngo Weinhold {
27*901f3990SIngo Weinhold 	int32_t se,hx,lx;
28*901f3990SIngo Weinhold 	GET_LDOUBLE_WORDS(se,hx,lx,x);
29*901f3990SIngo Weinhold 	/* This additional ^ 0x80000000 is necessary because in Intel's
30*901f3990SIngo Weinhold 	   internal representation of the implicit one is explicit.  */
31*901f3990SIngo Weinhold 	lx |= (hx ^ 0x80000000) | ((se & 0x7fff) ^ 0x7fff);
32*901f3990SIngo Weinhold 	lx |= -lx;
33*901f3990SIngo Weinhold 	se &= 0x8000;
34*901f3990SIngo Weinhold 	return ~(lx >> 31) & (1 - (se >> 14));
35*901f3990SIngo Weinhold }
36*901f3990SIngo Weinhold hidden_def (__isinfl)
37*901f3990SIngo Weinhold weak_alias (__isinfl, isinfl)
38