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glibc  2.9
Functions
fraiseexcpt.c File Reference
#include <fenv.h>
#include <float.h>
#include <math.h>
#include <shlib-compat.h>

Go to the source code of this file.

Functions

int __feraiseexcept (int excepts)

Function Documentation

int __feraiseexcept ( int  excepts)

Definition at line 26 of file fraiseexcpt.c.

{
  static const struct {
    double zero, one, max, min, pi;
  } c = {
    0.0, 1.0, DBL_MAX, DBL_MIN, M_PI
  };
  double d;

  /* Raise exceptions represented by EXPECTS.  But we must raise only
     one signal at a time.  It is important the if the overflow/underflow
     exception and the inexact exception are given at the same time,
     the overflow/underflow exception follows the inexact exception.  */

  /* First: invalid exception.  */
  if ((FE_INVALID & excepts) != 0)
    {
      /* One example of a invalid operation is 0/0.  */
      __asm ("" : "=e" (d) : "0" (c.zero));
      d /= c.zero;
      __asm __volatile ("" : : "e" (d));
    }

  /* Next: division by zero.  */
  if ((FE_DIVBYZERO & excepts) != 0)
    {
      __asm ("" : "=e" (d) : "0" (c.one));
      d /= c.zero;
      __asm __volatile ("" : : "e" (d));
    }

  /* Next: overflow.  */
  if ((FE_OVERFLOW & excepts) != 0)
    {
      __asm ("" : "=e" (d) : "0" (c.max));
      d *= d;
      __asm __volatile ("" : : "e" (d));
    }

  /* Next: underflow.  */
  if ((FE_UNDERFLOW & excepts) != 0)
    {
      __asm ("" : "=e" (d) : "0" (c.min));
      d *= d;
      __asm __volatile ("" : : "e" (d));
    }

  /* Last: inexact.  */
  if ((FE_INEXACT & excepts) != 0)
    {
      __asm ("" : "=e" (d) : "0" (c.one));
      d /= c.pi;
      __asm __volatile ("" : : "e" (d));
    }

  /* Success.  */
  return 0;
}