diff options
Diffstat (limited to 'newlib/libm/math/s_isnan.c')
| -rw-r--r-- | newlib/libm/math/s_isnan.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/newlib/libm/math/s_isnan.c b/newlib/libm/math/s_isnan.c new file mode 100644 index 00000000000..5d83fc04326 --- /dev/null +++ b/newlib/libm/math/s_isnan.c @@ -0,0 +1,122 @@ + +/* @(#)s_isnan.c 5.1 93/09/24 */ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +/* +FUNCTION + <<isnan>>,<<isnanf>>,<<isinf>>,<<isinff>>,<<finite>>,<<finitef>>---test for exceptional numbers + +INDEX + isnan +INDEX + isinf +INDEX + finite + +INDEX + isnanf +INDEX + isinff +INDEX + finitef + +ANSI_SYNOPSIS + #include <ieeefp.h> + int isnan(double <[arg]>); + int isinf(double <[arg]>); + int finite(double <[arg]>); + int isnanf(float <[arg]>); + int isinff(float <[arg]>); + int finitef(float <[arg]>); + +TRAD_SYNOPSIS + #include <ieeefp.h> + int isnan(<[arg]>) + double <[arg]>; + int isinf(<[arg]>) + double <[arg]>; + int finite(<[arg]>); + double <[arg]>; + int isnanf(<[arg]>); + float <[arg]>; + int isinff(<[arg]>); + float <[arg]>; + int finitef(<[arg]>); + float <[arg]>; + + +DESCRIPTION + These functions provide information on the floating point + argument supplied. + + There are five major number formats - + o+ + o zero + a number which contains all zero bits. + o subnormal + Is used to represent number with a zero exponent, but a non zero fraction. + o normal + A number with an exponent, and a fraction + o infinity + A number with an all 1's exponent and a zero fraction. + o NAN + A number with an all 1's exponent and a non zero fraction. + + o- + + <<isnan>> returns 1 if the argument is a nan. <<isinf>> + returns 1 if the argument is infinity. <<finite>> returns 1 if the + argument is zero, subnormal or normal. + + The <<isnanf>>, <<isinff>> and <<finitef>> perform the same + operations as their <<isnan>>, <<isinf>> and <<finite>> + counterparts, but on single precision floating point numbers. + +QUICKREF + isnan - pure +QUICKREF + isinf - pure +QUICKREF + finite - pure +QUICKREF + isnan - pure +QUICKREF + isinf - pure +QUICKREF + finite - pure +*/ + +/* + * isnan(x) returns 1 is x is nan, else 0; + * no branching! + */ + +#include "fdlibm.h" + +#ifndef _DOUBLE_IS_32BITS + +#ifdef __STDC__ + int isnan(double x) +#else + int isnan(x) + double x; +#endif +{ + __int32_t hx,lx; + EXTRACT_WORDS(hx,lx,x); + hx &= 0x7fffffff; + hx |= (__uint32_t)(lx|(-lx))>>31; + hx = 0x7ff00000 - hx; + return (int)(((__uint32_t)(hx))>>31); +} + +#endif /* _DOUBLE_IS_32BITS */ |