1 /*-------------------------------------------------------------------------
2 _ulong2fs.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 long __ulong2fs (float x)
dummy(void)37 static void dummy(void) __naked
38 {
39 __asm
40 .globl ___ulong2fs
41 ___ulong2fs:
42 mov r4, a
43 mov r3, b
44 mov r2, dph
45 mov r1, dpl
46 mov a, #158
47 .globl ulong2fs_doit
48 ulong2fs_doit:
49 clr sign_a
50 long2fs_doit:
51 mov exp_a, a
52 lcall fs_normalize_a
53 ljmp fs_round_and_return
54 __endasm;
55 }
56
57 #else
58
59 /*
60 ** libgcc support for software floating point.
61 ** Copyright (C) 1991 by Pipeline Associates, Inc. All rights reserved.
62 ** Permission is granted to do *anything* you want with this file,
63 ** commercial or otherwise, provided this message remains intact. So there!
64 ** I would appreciate receiving any updates/patches/changes that anyone
65 ** makes, and am willing to be the repository for said changes (am I
66 ** making a big mistake?).
67 **
68 ** Pat Wood
69 ** Pipeline Associates, Inc.
70 ** pipeline!phw@motown.com or
71 ** sun!pipeline!phw or
72 ** uunet!motown!pipeline!phw
73 */
74
75 /* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
76
77 union float_long
78 {
79 float f;
80 long l;
81 };
82
__ulong2fs(unsigned long a)83 float __ulong2fs (unsigned long a )
84 {
85 unsigned char exp = 24 + EXCESS;
86 volatile union float_long fl;
87
88 if (!a)
89 {
90 return 0.0;
91 }
92
93 while (a < HIDDEN)
94 {
95 a <<= 1;
96 exp--;
97 }
98
99 while (a & NORM)
100 {
101 // we lose accuracy here
102 if (a & 1)
103 a += 2;
104 a >>= 1;
105 exp++;
106 }
107
108 a &= ~HIDDEN ;
109 /* pack up and go home */
110 fl.l = PACK(0,(unsigned long)exp, a);
111
112 return (fl.f);
113 }
114
115 #endif
116