diff options
Diffstat (limited to 's_isnan.c')
-rw-r--r-- | s_isnan.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/s_isnan.c b/s_isnan.c new file mode 100644 index 0000000..0500c32 --- /dev/null +++ b/s_isnan.c @@ -0,0 +1,34 @@ + +/* @(#)s_isnan.c 1.3 95/01/18 */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunSoft, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +/* + * ieee_isnan(x) returns 1 is x is nan, else 0; + * no branching! + */ + +#include "fdlibm.h" + +#ifdef __STDC__ + int ieee_isnan(double x) +#else + int ieee_isnan(x) + double x; +#endif +{ + int hx,lx; + hx = (__HI(x)&0x7fffffff); + lx = __LO(x); + hx |= (unsigned)(lx|(-lx))>>31; + hx = 0x7ff00000 - hx; + return ((unsigned)(hx))>>31; +} |