sdcc/device/lib/_fs2schar.c

   1 /*-------------------------------------------------------------------------
   2    _fs2schar.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
  35 #ifdef FLOAT_ASM_MCS51
  36
  37 // char __fs2schar (float x)
  38 static void dummy(void) __naked
  39 {
  40         __asm
  41         .globl  ___fs2schar
  42 ___fs2schar:
  43         lcall   ___fs2slong
  44         jnz     fs2schar_not_zero
  45         mov     a, dpl
  46         orl     a, dph
  47         orl     a, b
  48         jnz     fs2schar_clr_a
  49         ret
  50 fs2schar_clr_a:
  51         clr a
  52 fs2schar_not_zero:
  53         jnb     sign_a, fs2schar_pos
  54 fs2schar_neg:
  55         cpl     a
  56         jnz     fs2schar_maxval_neg
  57         mov     a, b
  58         cpl     a
  59         jnz     fs2schar_maxval_neg
  60         mov     a, dph
  61         cpl     a
  62         jnz     fs2schar_maxval_neg
  63         mov     a, dpl
  64         jnb     acc.7, fs2schar_maxval_neg
  65         ret
  66 fs2schar_maxval_neg:
  67         mov     dpl, #0x80
  68         ret
  69 fs2schar_pos:
  70         jnz     fs2schar_maxval_pos
  71         mov     a, b
  72         jnz     fs2schar_maxval_pos
  73         mov     a, dph
  74         jnz     fs2schar_maxval_pos
  75         mov     a, dpl
  76         jb      acc.7, fs2schar_maxval_pos
  77         ret
  78 fs2schar_maxval_pos:
  79         mov     dpl, #0x7F
  80         ret
  81         __endasm;
  82 }
  83
  84 #else
  85
  86 /* convert float to signed char */
  87 signed char __fs2schar (float f) __SDCC_FLOAT_NONBANKED
  88 {
  89   signed long sl=__fs2slong(f);
  90   if (sl>=SCHAR_MAX)
  91     return SCHAR_MAX;
  92   if (sl<=SCHAR_MIN)
  93     return -SCHAR_MIN;
  94   return sl;
  95 }
  96
  97 #endif