fp_exception_mask()
Get or set the current exception mask
Synopsis:
#include <fpstatus.h> int fp_exception_mask ( int new_mask, int set );
Arguments:
- new_mask
- The new mask to apply.
The bits include:
- _FP_EXC_INVALID
- _FP_EXC_DIVZERO
- _FP_EXC_OVERFLOW
- _FP_EXC_UNDERFLOW
- _FP_EXC_INEXACT
- _FP_EXC_DENORMAL
- set
- A value that indicates what you want the function to do:
- If set < 0, return the current mask. The new_mask argument is ignored.
- If set = 0, disable the bits in the exception mask that correspond to the bits set in new_mask.
- If set > 0, enable the bits in the exception mask that correspond to the bits set in new_mask.
Description:
The fp_exception_mask() function gets or sets the current exception mask, depending on the value of the set argument.
Returns:
- If set < 0
- The current exception mask.
- If set ≥ 0
- The previous mask.
This function doesn't return a special value to indicate that an error
occurred.
If you want to check for errors, set
errno
to 0, call the function, and then check errno again.
Examples:
#include <fpstatus.h>
int main(int argc, char** argv)
{
int ret;
if ((ret = fp_exception_mask(0, -1)) < 0)
printf("*** Problem retrieving exceptions \n");
printf("Exceptions Enabled: \n\t");
if (ret & _FP_EXC_INEXACT)
printf("Inexact ");
if (ret & _FP_EXC_DIVZERO)
printf("DivZero ");
if (ret & _FP_EXC_UNDERFLOW)
printf("Underflow ");
if (ret & _FP_EXC_OVERFLOW)
printf("Overflow ");
if (ret & _FP_EXC_INVALID)
printf("Invalid ");
printf("\n");
/* Set the exception mask to enable division by zero errors */
if ((ret = fp_exception_mask(_FP_EXC_DIVZERO, 1)) < 0)
printf("*** Problem setting exceptions \n");
if ((ret = fp_exception_mask(0, -1)) < 0)
printf("*** Problem retrieving exceptions \n");
printf("Exceptions Enabled: \n\t");
if (ret & _FP_EXC_INEXACT)
printf("Inexact ");
if (ret & _FP_EXC_DIVZERO)
printf("DivZero ");
if (ret & _FP_EXC_UNDERFLOW)
printf("Underflow ");
if (ret & _FP_EXC_OVERFLOW)
printf("Overflow ");
if (ret & _FP_EXC_INVALID)
printf("Invalid ");
printf("\n");
return(0);
}
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | No |
| Thread | Yes |