sdcc/device/lib/_fs2slong.c

   1 /*-------------------------------------------------------------------------
   2    _fs2slong.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 // long __fs2slong (float x)
  37 static void dummy(void) __naked
  38 {
  39         __asm
  40         .globl  ___fs2slong
  41 ___fs2slong:
  42         lcall   fsgetarg
  43         clr     c
  44         mov     a, #158
  45         subb    a, exp_a
  46         jc      fs2slong_maxval         //  |x| >= 2^32
  47 fs2slong_int_ok:
  48         mov     r1, #0
  49         lcall   fs_rshift_a
  50         jnb     sign_a, fs2slong_pos
  51 fs2slong_neg:
  52         mov     a, r1
  53         cpl     a
  54         add     a, #1
  55         mov     dpl, a
  56         mov     a, r2
  57         cpl     a
  58         addc    a, #0
  59         mov     dph, a
  60         mov     a, r3
  61         cpl     a
  62         addc    a, #0
  63         mov     b, a
  64         mov     a, r4
  65         cpl     a
  66         addc    a, #0
  67         //Check for zero
  68         jnz fs2slong_not_zero
  69         mov a, dpl
  70         orl a, dph
  71         orl a, b
  72         jnz fs2slong_clr_a
  73         ret
  74 fs2slong_clr_a:
  75         clr a
  76 fs2slong_not_zero:
  77         jnb acc.7, fs2slong_maxval_neg  // x < -0x80000000
  78         ret
  79 fs2slong_pos:
  80         mov     a, r4
  81         jb      acc.7, fs2slong_maxval_pos  //  x > 0x7FFFFFFF
  82         mov     dpl, r1
  83         mov     dph, r2
  84         mov     b, r3
  85         ret
  86 fs2slong_maxval:
  87         jnb     sign_a, fs2slong_maxval_pos
  88 fs2slong_maxval_neg:
  89         clr     a
  90         mov     dpl, a
  91         mov     dph, a
  92         mov     b, a
  93         mov     a, #0x80
  94         ret
  95 fs2slong_maxval_pos:
  96         mov     a, #0xFF
  97         mov     dpl, a
  98         mov     dph, a
  99         mov     b, a
 100         mov     a, #0x7F
 101         ret
 102         __endasm;
 103 }
 104
 105 #else
 106
 107 /* convert float to signed long */
 108 signed long __fs2slong (float f) __SDCC_FLOAT_NONBANKED
 109 {
 110
 111   if (!f)
 112     return 0;
 113
 114   if (f<0) {
 115     return -__fs2ulong(-f);
 116   } else {
 117     return __fs2ulong(f);
 118   }
 119 }
 120
 121 #endif