Header File 

float.h  

Category 

Math Routines 

Prototype 

unsigned int _clear87 (void); 

unsigned int _clearfp (void); 

Description 

Clears the floating-point status word. 

_clear87 clears the floating-point status word, which is a combination of the 80x87 status word and other conditions detected by the 80x87 exception handler. 

_clearfp is identical to _clear87 and is for Microsoft compatibility. 

Return Value 

The bits in the value returned indicate the floating-point status before it was cleared. For information on the status word, refer to the constants defined in float.h. 

Example  

#include <stdio.h>
#include <float.h>
int main(void)
{
   float x;
   double y = 1.5e-100;
   printf("\nStatus 87 before error: %X\n", _status87());
   x = y; /* create underflow and precision loss */
   printf("Status 87 after  error: %X\n", _status87());
   _clear87();
   printf("Status 87 after  clear: %X\n", _status87());
   y = x;
   return 0;
}

Portability