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glibc  2.9
fsetexcptflg.c File Reference
#include <fenv.h>
#include <math.h>

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int fesetexceptflag (const fexcept_t *flagp, int excepts)

Function Documentation

int fesetexceptflag ( const fexcept_t flagp,
int  excepts 

Definition at line 24 of file fsetexcptflg.c.

  fenv_t temp;
  unsigned int mxcsr;

  /* XXX: Do we really need to set both the exception in both units?
     Shouldn't it be enough to set only the SSE unit?  */

  /* Get the current x87 FPU environment.  We have to do this since we
     cannot separately set the status word.  */
  __asm__ ("fnstenv %0" : "=m" (*&temp));

  temp.__status_word &= ~(excepts & FE_ALL_EXCEPT);
  temp.__status_word |= *flagp & excepts & FE_ALL_EXCEPT;

  /* Store the new status word (along with the rest of the environment.
     Possibly new exceptions are set but they won't get executed unless
     the next floating-point instruction.  */
  __asm__ ("fldenv %0" : : "m" (*&temp));

  /* And now the same for SSE.  */
  __asm__ ("stmxcsr %0" : "=m" (*&mxcsr));

  mxcsr &= ~(excepts & FE_ALL_EXCEPT);
  mxcsr |= *flagp & excepts & FE_ALL_EXCEPT;

  __asm__ ("ldmxcsr %0" : : "m" (*&mxcsr));

  /* Success.  */
  return 0;

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