1 /*-------------------------------------------------------------------------
2 _fslt.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 // char __fslt (float a, float b)
dummy(void)37 static void dummy(void) __naked
38 {
39 __asm
40 .globl ___fslt
41 ___fslt:
42 mov r7, a
43 mov r0, sp
44 dec r0
45 dec r0
46 lcall fs_check_negative_zeros
47 setb sign_a
48 rlc a
49 mov a, @r0
50 jc a_negative
51 a_positive:
52 jnb acc.7, ab_positive
53 // a is positive and b is negative, so a > b
54 mov dpl, #0
55 ret
56 a_negative:
57 jb acc.7, ab_negative
58 // a is negative and b is positive, so a < b
59 mov dpl, #1
60 ret
61 ab_positive:
62 clr sign_a
63 ab_negative:
64 lcall fs_compare_uint32
65 mov a, r1
66 jnz ab_different
67 // a and b are equal
68 mov dpl, a
69 ret
70 ab_different:
71 jb sign_a, skip_invert
72 cpl c
73 skip_invert:
74 clr a
75 rlc a
76 mov dpl, a
77 ret
78 __endasm;
79 }
80
81 #else
82
83 /*
84 ** libgcc support for software floating point.
85 ** Copyright (C) 1991 by Pipeline Associates, Inc. All rights reserved.
86 ** Permission is granted to do *anything* you want with this file,
87 ** commercial or otherwise, provided this message remains intact. So there!
88 ** I would appreciate receiving any updates/patches/changes that anyone
89 ** makes, and am willing to be the repository for said changes (am I
90 ** making a big mistake?).
91 **
92 ** Pat Wood
93 ** Pipeline Associates, Inc.
94 ** pipeline!phw@motown.com or
95 ** sun!pipeline!phw or
96 ** uunet!motown!pipeline!phw
97 */
98
99 /* (c)2000/2001: hacked a little by johan.knol@iduna.nl for sdcc */
100
101 union float_long
102 {
103 float f;
104 long l;
105 };
106
107 /* compare two floats */
__fslt(float a1,float a2)108 char __fslt (float a1, float a2)
109 {
110 volatile union float_long fl1, fl2;
111
112 fl1.f = a1;
113 fl2.f = a2;
114
115 if (((fl1.l | fl2.l) & 0x7FFFFFFF) == 0)
116 return (0);
117
118 if (fl1.l<0 && fl2.l<0) {
119 if (fl2.l < fl1.l)
120 return (1);
121 return (0);
122 }
123
124 if (fl1.l < fl2.l)
125 return (1);
126 return (0);
127 }
128
129 #endif
130