text: /* Test of hypot*() function family.
     Copyright (C) 2012 Free Software Foundation, Inc.
  
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 3 of the License, or
     (at your option) any later version.
  
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  
  static void
  test_function (void)
  {
    int i;
    int j;
    const DOUBLE TWO_MANT_DIG =
      /* Assume MANT_DIG <= 5 * 31.
         Use the identity
           n = floor(n/5) + floor((n+1)/5) + ... + floor((n+4)/5).  */
      (DOUBLE) (1U << ((MANT_DIG - 1) / 5))
      * (DOUBLE) (1U << ((MANT_DIG - 1 + 1) / 5))
      * (DOUBLE) (1U << ((MANT_DIG - 1 + 2) / 5))
      * (DOUBLE) (1U << ((MANT_DIG - 1 + 3) / 5))
      * (DOUBLE) (1U << ((MANT_DIG - 1 + 4) / 5));
  
    {
      volatile DOUBLE x;
      volatile DOUBLE y;
      DOUBLE z;
  
      /* Overflow.  */
      x = MAX;
      y = MAX * L_(0.5);
      z = HYPOT (x, y);
      ASSERT (z == HUGEVAL);
  
      /* No underflow.  */
      x = MIN;
      y = L_(0.0);
      z = HYPOT (x, y);
      ASSERT (z == MIN);
  
      /* No underflow.  */
      x = MIN * L_(2.0);
      y = MIN * L_(3.0);
      z = HYPOT (x, y);
      ASSERT (z >= MIN * L_(2.0) && z <= MIN * L_(4.0));
    }
  
    /* Randomized tests.  */
    for (i = 0; i < SIZEOF (RANDOM) / 5; i++)
      for (j = 0; j < SIZEOF (RANDOM) / 5;j++)
        {
          DOUBLE x = L_(16.0) * RANDOM[i]; /* 0.0 <= x <= 16.0 */
          DOUBLE y = L_(16.0) * RANDOM[j]; /* 0.0 <= y <= 16.0 */
          DOUBLE z = HYPOT (x, y);
          DOUBLE err = z * z - (x * x + y * y);
          ASSERT (z >= L_(0.0));
          ASSERT (err >= - L_(4.0) * L_(16.0) * L_(16.0) / TWO_MANT_DIG
                  && err <= L_(4.0) * L_(16.0) * L_(16.0) / TWO_MANT_DIG);
        }
  }
  
  volatile DOUBLE x;
  volatile DOUBLE y;
  DOUBLE z;
  