sysdeps/ieee754/ldbl-96/x2y2m1.c

   1 /* Compute x^2 + y^2 - 1, without large cancellation error.
   2    Copyright (C) 2012-2014 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <math.h>
  20 #include <math_private.h>
  21 #include <float.h>
  22
  23 #if FLT_EVAL_METHOD == 0
  24
  25 # include <sysdeps/ieee754/dbl-64/x2y2m1.c>
  26
  27 #else
  28
  29 /* Return X^2 + Y^2 - 1, computed without large cancellation error.
  30    It is given that 1 > X >= Y >= epsilon / 2, and that either X >=
  31    0.75 or Y >= 0.5.  */
  32
  33 double
  34 __x2y2m1 (double x, double y)
  35 {
  36   return (double) __x2y2m1l (x, y);
  37 }
  38
  39 #endif