gnu/dist/gcc4/gcc/testsuite/gcc.c-torture/execute/990413-2.c

   1 /* This tests for a bug in regstack that was breaking glibc's math library. */
   2
   3 extern void abort (void);
   4
   5 static __inline double
   6 minus_zero (void)
   7 {
   8   union { double __d; int __i[2]; } __x;
   9   __x.__i[0] = 0x0;
  10   __x.__i[1] = 0x80000000;
  11   return __x.__d;
  12 }
  13
  14 static __inline long double
  15 __atan2l (long double __y, long double __x)
  16 {
  17   register long double __value;
  18   __asm __volatile__ ("fpatan\n\t"
  19                       : "=t" (__value)
  20                       : "0" (__x), "u" (__y)
  21                       : "st(1)");
  22   return __value;
  23 }
  24
  25 static __inline long double
  26 __sqrtl (long double __x)
  27 {
  28   register long double __result;
  29   __asm __volatile__ ("fsqrt" : "=t" (__result) : "0" (__x));
  30   return __result;
  31 }
  32
  33 static __inline double
  34 asin (double __x)
  35 {
  36   return __atan2l (__x, __sqrtl (1.0 - __x * __x));
  37 }
  38
  39 int
  40 main (void)
  41 {
  42   double x;
  43
  44   x = minus_zero();
  45   x = asin (x);
  46
  47   if (x != 0.0) /* actually -0.0, but 0.0 == -0.0 */
  48     abort ();
  49   return 0;
  50 }