sysdeps/i386/fpu/s_fdim.S

   1 /* Compute positive difference.
   2    Copyright (C) 1997, 1999, 2004 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <sysdep.h>
  21
  22         .text
  23 ENTRY(__fdim)
  24         fldl    4(%esp)         // x
  25         fldl    12(%esp)        // x : y
  26
  27         fucom   %st(1)
  28         fnstsw
  29         sahf
  30         jp      1f
  31
  32         jc      3f
  33
  34         fstp    %st(1)
  35         fldz
  36         jmp     2f
  37
  38 3:      fsubrp  %st, %st(1)
  39         ret
  40
  41 1:      fxam
  42         fnstsw
  43         andb    $0x45, %ah
  44         cmpb    $0x01, %ah
  45         je      2f
  46
  47         fxch
  48 2:      fstp    %st(1)
  49         ret
  50 END(__fdim)
  51 weak_alias (__fdim, fdim)