_chkdouble_

Summary

#include <intrins.h>
/* or */
#include <math.h>

unsigned int _chkdouble_ (
  double val);       /* number to check */

Description

The _chkdouble_ function checks the status of the floating-point number val.

Return Value

The _chkdouble_ function returns the status of the floating-point number val:

Return Value	Meaning
0	Standard floating-point number.
1	Floating-point value 0.
2	+INF (positive overflow).
3	-INF (negative overflow).
4	NaN (Not a Number) error status.

See Also

_chkfloat_

Example

#include <intrins.h>
#include <stdio.h> /* for printf */

float f1, f2, f3;

void tst_chkdouble (void) {
  f1 = f2 * f3;

  switch (_chkdouble_ (f1)) {
    case 0:
      printf ("result is a number\n"); break;
    case 1:
      printf ("result is zero\n"); break;
    case 2:
      printf ("result is +INF\n"); break;
    case 3:
      printf ("result is -INF\n"); break;
    case 4:
      printf ("result is NaN\n"); break;
  }
}