sysdeps/m68k/fpu/k_tan.c

   1 /* Copyright (C) 1996 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <math.h>
  20
  21 #ifndef FUNC
  22 #define FUNC tan
  23 #endif
  24 #ifndef float_type
  25 #define float_type double
  26 #endif
  27
  28 #define __CONCATX(a,b) __CONCAT(a,b)
  29
  30 float_type
  31 __CONCATX(__kernel_,FUNC) (x, y, iy)
  32      float_type x;
  33      float_type y;
  34      int iy;
  35 {
  36   float_type tan_x, tan_y;
  37   tan_x = __m81_u_(__CONCATX(__,FUNC)) (x);
  38   tan_y = __m81_u_(__CONCATX(__,FUNC)) (y);
  39   if (iy > 0)
  40     return (tan_x + tan_y) / (1 - tan_x * tan_y);
  41   else
  42     return (tan_x * tan_y - 1) / (tan_x + tan_y);
  43 }