sdcc/device/lib/_fssub.c

   1 /*-------------------------------------------------------------------------
   2    _fssub.c - Floating point library in optimized assembly for 8051
   3
   4    Copyright (c) 2004, Paul Stoffregen, paul@pjrc.com
   5
   6    This library is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 2, or (at your option) any
   9    later version.
  10
  11    This 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
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this library; see the file COPYING. If not, write to the
  18    Free Software Foundation, 51 Franklin Street, Fifth Floor, Boston,
  19    MA 02110-1301, USA.
  20
  21    As a special exception, if you link this library with other files,
  22    some of which are compiled with SDCC, to produce an executable,
  23    this library does not by itself cause the resulting executable to
  24    be covered by the GNU General Public License. This exception does
  25    not however invalidate any other reasons why the executable file
  26    might be covered by the GNU General Public License.
  27 -------------------------------------------------------------------------*/
  28
  29
  30 #define __SDCC_FLOAT_LIB
  31 #include <float.h>
  32
  33
  34 #ifdef FLOAT_ASM_MCS51
  35
  36 //float __fssub (float a, float b) __reentrant
  37 static void dummy(void) __naked
  38 {
  39         __asm
  40         .globl  ___fssub
  41 ___fssub:
  42         mov     r0, sp
  43         dec     r0
  44         dec     r0
  45         xch     a, @r0
  46         cpl     acc.7
  47         xch     a, @r0
  48         ljmp    ___fsadd
  49         __endasm;
  50 }
  51
  52 #else
  53
  54 /*
  55 ** libgcc support for software floating point.
  56 ** Copyright (C) 1991 by Pipeline Associates, Inc.  All rights reserved.
  57 ** Permission is granted to do *anything* you want with this file,
  58 ** commercial or otherwise, provided this message remains intact.  So there!
  59 ** I would appreciate receiving any updates/patches/changes that anyone
  60 ** makes, and am willing to be the repository for said changes (am I
  61 ** making a big mistake?).
  62 **
  63 ** Pat Wood
  64 ** Pipeline Associates, Inc.
  65 ** pipeline!phw@motown.com or
  66 ** sun!pipeline!phw or
  67 ** uunet!motown!pipeline!phw
  68 */
  69
  70 /* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
  71
  72 /* subtract two floats */
  73 float __fssub (float a1, float a2) __SDCC_FLOAT_NONBANKED
  74 {
  75   float neg = -a1;
  76   return -(neg + a2);
  77 }
  78
  79 #endif