glibc/sysdeps/i386/fpu/s_isinfl.c
2012-01-27 17:29:45 +00:00

33 lines
770 B
C

/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Change for long double by Ulrich Drepper <drepper@cygnus.com>.
* Intel i387 specific version.
* Public domain.
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: $";
#endif
/*
* isinfl(x) returns 1 if x is inf, -1 if x is -inf, else 0;
* no branching!
*/
#include "math.h"
#include "math_private.h"
int __isinfl(long double x)
{
int32_t se,hx,lx;
GET_LDOUBLE_WORDS(se,hx,lx,x);
/* This additional ^ 0x80000000 is necessary because in Intel's
internal representation of the implicit one is explicit. */
lx |= (hx ^ 0x80000000) | ((se & 0x7fff) ^ 0x7fff);
lx |= -lx;
se &= 0x8000;
return ~(lx >> 31) & (1 - (se >> 14));
}
hidden_def (__isinfl)
weak_alias (__isinfl, isinfl)