sysdeps/m68k/fpu/k_tan.c

   1 /* Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <math.h>
  20 #include "math_private.h"
  21
  22 #ifndef FUNC
  23 #define FUNC tan
  24 #endif
  25 #ifndef float_type
  26 #define float_type double
  27 #endif
  28
  29 #define __CONCATX(a,b) __CONCAT(a,b)
  30
  31 float_type
  32 __CONCATX(__kernel_,FUNC) (x, y, iy)
  33      float_type x;
  34      float_type y;
  35      int iy;
  36 {
  37   float_type tan_x, tan_y;
  38   tan_x = __m81_u(__CONCATX(__,FUNC)) (x);
  39   tan_y = __m81_u(__CONCATX(__,FUNC)) (y);
  40   if (iy > 0)
  41     return (tan_x + tan_y) / (1 - tan_x * tan_y);
  42   else
  43     return (tan_x * tan_y - 1) / (tan_x + tan_y);
  44 }