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 /* { dg-skip-if "" { ! { i?86-*-* x86_64-*-* } } } */
   3
   4 extern void abort (void);
   5
   6 static __inline double
   7 minus_zero (void)
   8 {
   9   union { double __d; int __i[2]; } __x;
  10   __x.__i[0] = 0x0;
  11   __x.__i[1] = 0x80000000;
  12   return __x.__d;
  13 }
  14
  15 static __inline long double
  16 __atan2l (long double __y, long double __x)
  17 {
  18   register long double __value;
  19   __asm __volatile__ ("fpatan\n\t"
  20                       : "=t" (__value)
  21                       : "0" (__x), "u" (__y)
  22                       : "st(1)");
  23   return __value;
  24 }
  25
  26 static __inline long double
  27 __sqrtl (long double __x)
  28 {
  29   register long double __result;
  30   __asm __volatile__ ("fsqrt" : "=t" (__result) : "0" (__x));
  31   return __result;
  32 }
  33
  34 static __inline double
  35 asin (double __x)
  36 {
  37   return __atan2l (__x, __sqrtl (1.0 - __x * __x));
  38 }
  39
  40 int
  41 main (void)
  42 {
  43   double x;
  44
  45   x = minus_zero();
  46   x = asin (x);
  47
  48   if (x != 0.0) /* actually -0.0, but 0.0 == -0.0 */
  49     abort ();
  50   return 0;
  51 }