sdcc/device/lib/_fs2sint.c

   1 /*-------------------------------------------------------------------------
   2    _fs2sint.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 // int __fs2sint (float x)
  37 static void dummy(void) __naked
  38 {
  39         __asm
  40         .globl  ___fs2sint
  41 ___fs2sint:
  42         lcall   ___fs2slong
  43         jnz fs2sint_not_zero
  44         mov a, dpl
  45         orl a, dph
  46         orl a, b
  47         jnz fs2sint_clr_a
  48         ret
  49 fs2sint_clr_a:
  50         clr a
  51 fs2sint_not_zero:
  52         jnb     sign_a, fs2sint_pos
  53 fs2sint_neg:
  54         cpl     a
  55         jnz     fs2sint_maxval_neg
  56         mov     a, b
  57         cpl     a
  58         jnz     fs2sint_maxval_neg
  59         mov     a, dph
  60         jnb     acc.7, fs2sint_maxval_neg
  61         ret
  62 fs2sint_maxval_neg:
  63         mov     dptr, #0x8000
  64         ret
  65 fs2sint_pos:
  66         jnz     fs2sint_maxval_pos
  67         mov     a, b
  68         jnz     fs2sint_maxval_pos
  69         mov     a, dph
  70         jb      acc.7, fs2sint_maxval_pos
  71         ret
  72 fs2sint_maxval_pos:
  73         mov     dptr, #0x7FFF
  74         ret
  75         __endasm;
  76 }
  77
  78 #else
  79
  80 /* convert float to signed int */
  81 signed int __fs2sint (float f) __SDCC_FLOAT_NONBANKED
  82 {
  83   signed long sl=__fs2slong(f);
  84   if (sl>=INT_MAX)
  85     return INT_MAX;
  86   if (sl<=INT_MIN)
  87     return -INT_MIN;
  88   return sl;
  89 }
  90
  91 #endif