sdcc/device/lib/_slong2fs.c

   1 /*-------------------------------------------------------------------------
   2    _slong2fs.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 __slong2fs (long x)
  37 static void dummy(void) __naked
  38 {
  39         __asm
  40         .globl  ___slong2fs
  41 ___slong2fs:
  42         mov     r4, a
  43         mov     r3, b
  44         mov     r2, dph
  45         mov     r1, dpl
  46         mov     a, #158
  47         .globl  slong2fs_doit
  48 slong2fs_doit:
  49         mov     exp_a, a
  50         clr     sign_a
  51         mov     a, r4
  52         jnb     acc.7, slong2fs_positive
  53         setb    sign_a
  54         mov     a, r1
  55         cpl     a
  56         add     a, #1
  57         mov     r1, a
  58         mov     a, r2
  59         cpl     a
  60         addc    a, #0
  61         mov     r2, a
  62         mov     a, r3
  63         cpl     a
  64         addc    a, #0
  65         mov     r3, a
  66         mov     a, r4
  67         cpl     a
  68         addc    a, #0
  69         mov     r4, a
  70 slong2fs_positive:
  71         lcall   fs_normalize_a
  72         ljmp    fs_round_and_return
  73         __endasm;
  74 }
  75
  76 #else
  77
  78 /* convert signed long to float */
  79 float __slong2fs (signed long sl) __SDCC_FLOAT_NONBANKED
  80 {
  81   if (sl<0)
  82     return -__ulong2fs(-sl);
  83   else
  84     return __ulong2fs(sl);
  85 }
  86
  87 #endif