gcc/testsuite/gcc.c-torture/compile/980506-2.c

   1 /*
   2  * inspired by glibc-2.0.6/sysdeps/libm-ieee754/s_nextafterf.c
   3  *
   4  * gcc -O2 -S -DOP=+ gives faddp %st(1),%st
   5  * gcc -O2 -S -DOP=* gives fmulp %st(1),%st
   6  * gcc -O2 -S -DOP=- gives fsubrp %st(1),%st
   7  * gcc -O2 -S -DOP=/ gives fdivrp %st(1),%st
   8  */
   9
  10 #ifndef OP
  11 #define OP *
  12 #endif
  13
  14 typedef int int32_t __attribute__ ((__mode__ (  __SI__ ))) ;
  15 typedef unsigned int u_int32_t __attribute__ ((__mode__ (  __SI__ ))) ;
  16
  17 typedef union
  18 {
  19   float value;
  20   u_int32_t word;
  21 } ieee_float_shape_type;
  22
  23 float __nextafterf(float x, float y)
  24 {
  25  int32_t hx,hy,ix,iy;
  26
  27  {
  28   ieee_float_shape_type gf_u;
  29   gf_u.value = x;
  30   hx = gf_u.word;
  31  }
  32  {
  33   ieee_float_shape_type gf_u;
  34   gf_u.value = y;
  35   hy = gf_u.word;
  36  }
  37  ix = hx&0x7fffffff;
  38  iy = hy&0x7fffffff;
  39
  40  if ( ix > 0x7f800000 || iy > 0x7f800000 )
  41     return x+y;
  42  if (x == y) return x;
  43  if (ix == 0)
  44    {
  45     {
  46      ieee_float_shape_type sf_u;
  47      sf_u.word = (hy&0x80000000) | 1;
  48      x = sf_u.value;
  49     }
  50     y = x*x;
  51     if (y == x) return y; else return x;
  52    }
  53  if (hx >= 0)
  54    {
  55     if (hx > hy)
  56        hx -= 1;
  57     else
  58        hx += 1;
  59    }
  60  else
  61    {
  62     if (hy >= 0 || hx > hy)
  63        hx -= 1;
  64     else
  65        hx += 1;
  66    }
  67  hy = hx & 0x7f800000;
  68  if (hy >= 0x7f800000)
  69     return x+x;
  70  if (hy < 0x00800000)
  71    {
  72     y = x OP x;
  73     if (y != x)
  74       {
  75        ieee_float_shape_type sf_u;
  76        sf_u.word = hx;
  77        y = sf_u.value;
  78        return y;
  79       }
  80    }
  81  {
  82   ieee_float_shape_type sf_u;
  83   sf_u.word = hx;
  84   x = sf_u.value;
  85  }
  86  return x;
  87 }
  88
  89