ISNAND(3C) Standard C Library Functions ISNAND(3C)

NAME

isnand, isnanf, finite, fpclass, unordered - determine type of
floating-point number

SYNOPSIS

#include <ieeefp.h>

int isnand(double dsrc);


int isnanf(float fsrc);


int finite(double dsrc);


fpclass_t fpclass(double dsrc);


int unordered(double dsrc1, double dsrc2);

DESCRIPTION

The isnand() and isnanf() functions return TRUE (1) if the argument
dsrc or fsrc is a NaN; otherwise they return FALSE (0).


The fpclass() function returns one of the following classes to which
dsrc belongs:

FP_SNAN
signaling NaN


FP_QNAN
quiet NaN


FP_NINF
negative infinity


FP_PINF
positive infinity


FP_NDENORM
negative denormalized non-zero


FP_PDENORM
positive denormalized non-zero


FP_NZERO
negative zero


FP_PZERO
positive zero


FP_NNORM
negative normalized non-zero


FP_PNORM
positive normalized non-zero


The finite() function returns TRUE (1) if the argument dsrc is
neither infinity nor NaN; otherwise it returns FALSE (0).


The unordered() function returns TRUE (1) if one of its two arguments
is unordered with respect to the other argument. This is equivalent
to reporting whether either argument is NaN. If neither argument is
NaN, FALSE (0) is returned.


None of these functions generates an exception, even for signaling
NaNs.

RETURN VALUES

See DESCRIPTION.

ATTRIBUTES

See attributes(7) for descriptions of the following attributes:


+---------------+-----------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+-----------------+
|MT-Level | MT-Safe |
+---------------+-----------------+

SEE ALSO

fpgetround(3C), isnan(3M), attributes(7)

June 15, 2004 ISNAND(3C)