sdcc/device/lib/_fs2ulong.c

   1 /*-------------------------------------------------------------------------
   2    _fs2ulong.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 // unsigned long __fs2ulong (float x)
  37 static void dummy(void) __naked
  38 {
  39         __asm
  40         .globl  ___fs2ulong
  41 ___fs2ulong:
  42         mov     r7, #158
  43         .globl  fs2ulong_begin
  44 fs2ulong_begin:
  45         lcall   fsgetarg
  46         jnb     sign_a, fs2ulong_int
  47         ljmp    fs_return_zero
  48
  49 fs2ulong_int:
  50         clr     c
  51         mov     a, r7
  52         subb    a, exp_a
  53         jnc     fs2ulong_int_ok
  54         // if we get here, x >= 2^32
  55         mov     a, #0xFF
  56         mov     b, a
  57         mov     dph, a
  58         mov     dpl, a
  59         ret
  60
  61 fs2ulong_int_ok:
  62         mov     r1, #0
  63         lcall   fs_rshift_a
  64
  65 fs2ulong_done:
  66         mov     dpl, r1
  67         mov     dph, r2
  68         mov     b, r3
  69         mov     a, r4
  70         ret
  71         __endasm;
  72 }
  73
  74 #else
  75
  76 /*
  77 ** libgcc support for software floating point.
  78 ** Copyright (C) 1991 by Pipeline Associates, Inc.  All rights reserved.
  79 ** Permission is granted to do *anything* you want with this file,
  80 ** commercial or otherwise, provided this message remains intact.  So there!
  81 ** I would appreciate receiving any updates/patches/changes that anyone
  82 ** makes, and am willing to be the repository for said changes (am I
  83 ** making a big mistake?).
  84 **
  85 ** Pat Wood
  86 ** Pipeline Associates, Inc.
  87 ** pipeline!phw@motown.com or
  88 ** sun!pipeline!phw or
  89 ** uunet!motown!pipeline!phw
  90 */
  91
  92 /* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
  93 /* (c)2022:      fix sdcc bug #3276 -- Benedikt Freisen */
  94
  95
  96 union float_long
  97 {
  98   float f;
  99   long l;
 100 };
 101
 102 /* convert float to unsigned long */
 103 unsigned long __fs2ulong (float a1) __SDCC_FLOAT_NONBANKED
 104 {
 105   volatile union float_long fl1;
 106   int exp;
 107   unsigned long l;
 108
 109   fl1.f = a1;
 110
 111   if (!fl1.l || SIGN(fl1.l))
 112     return (0);
 113
 114   exp = EXP (fl1.l) - EXCESS - 24;
 115   l = MANT (fl1.l);
 116
 117   if (exp > 8)
 118     return 0xfffffffful;
 119
 120   if (exp < 0)
 121     l >>= -exp;
 122   else
 123     l <<= exp;
 124
 125   return l;
 126 }
 127
 128 #endif