1 /* libgcc1 routines for 68000 w/o floating-poi 1 /* libgcc1 routines for 68000 w/o floating-point hardware.
2 Copyright (C) 1994, 1996, 1997, 1998 Free S 2 Copyright (C) 1994, 1996, 1997, 1998 Free Software Foundation, Inc.
3 3
4 This file is part of GNU CC. 4 This file is part of GNU CC.
5 5
6 GNU CC is free software; you can redistribute 6 GNU CC is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public Lice 7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; either version 2, or 8 Free Software Foundation; either version 2, or (at your option) any
9 later version. 9 later version.
10 10
11 In addition to the permissions in the GNU Gene 11 In addition to the permissions in the GNU General Public License, the
12 Free Software Foundation gives you unlimited p 12 Free Software Foundation gives you unlimited permission to link the
13 compiled version of this file with other progr 13 compiled version of this file with other programs, and to distribute
14 those programs without any restriction coming 14 those programs without any restriction coming from the use of this
15 file. (The General Public License restriction 15 file. (The General Public License restrictions do apply in other
16 respects; for example, they cover modification 16 respects; for example, they cover modification of the file, and
17 distribution when not linked into another prog 17 distribution when not linked into another program.)
18 18
19 This file is distributed in the hope that it w 19 This file is distributed in the hope that it will be useful, but
20 WITHOUT ANY WARRANTY; without even the implied 20 WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PU 21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 General Public License for more details. */ 22 General Public License for more details. */
23 23
24 /* As a special exception, if you link this li 24 /* As a special exception, if you link this library with files
25 compiled with GCC to produce an executable, 25 compiled with GCC to produce an executable, this does not cause
26 the resulting executable to be covered by t 26 the resulting executable to be covered by the GNU General Public License.
27 This exception does not however invalidate 27 This exception does not however invalidate any other reasons why
28 the executable file might be covered by the 28 the executable file might be covered by the GNU General Public License. */
29 29
30 /* Use this one for any 680x0; assumes no floa 30 /* Use this one for any 680x0; assumes no floating point hardware.
31 The trailing " '" appearing on some lines i 31 The trailing " '" appearing on some lines is for ANSI preprocessors. Yuk.
32 Some of this code comes from MINIX, via the 32 Some of this code comes from MINIX, via the folks at ericsson.
33 D. V. Henkel-Wallace (gumby@cygnus.com) Fet 33 D. V. Henkel-Wallace (gumby@cygnus.com) Fete Bastille, 1992
34 */ 34 */
35 #include <linux/export.h> 35 #include <linux/export.h>
36 /* These are predefined by new versions of GNU 36 /* These are predefined by new versions of GNU cpp. */
37 37
38 #ifndef __USER_LABEL_PREFIX__ 38 #ifndef __USER_LABEL_PREFIX__
39 #define __USER_LABEL_PREFIX__ _ 39 #define __USER_LABEL_PREFIX__ _
40 #endif 40 #endif
41 41
42 #ifndef __REGISTER_PREFIX__ 42 #ifndef __REGISTER_PREFIX__
43 #define __REGISTER_PREFIX__ 43 #define __REGISTER_PREFIX__
44 #endif 44 #endif
45 45
46 #ifndef __IMMEDIATE_PREFIX__ 46 #ifndef __IMMEDIATE_PREFIX__
47 #define __IMMEDIATE_PREFIX__ # 47 #define __IMMEDIATE_PREFIX__ #
48 #endif 48 #endif
49 49
50 /* ANSI concatenation macros. */ 50 /* ANSI concatenation macros. */
51 51
52 #define CONCAT1(a, b) CONCAT2(a, b) 52 #define CONCAT1(a, b) CONCAT2(a, b)
53 #define CONCAT2(a, b) a ## b 53 #define CONCAT2(a, b) a ## b
54 54
55 /* Use the right prefix for global labels. */ 55 /* Use the right prefix for global labels. */
56 56
57 #define SYM(x) CONCAT1 (__USER_LABEL_PREFIX__, 57 #define SYM(x) CONCAT1 (__USER_LABEL_PREFIX__, x)
58 58
59 /* Use the right prefix for registers. */ 59 /* Use the right prefix for registers. */
60 60
61 #define REG(x) CONCAT1 (__REGISTER_PREFIX__, x 61 #define REG(x) CONCAT1 (__REGISTER_PREFIX__, x)
62 62
63 /* Use the right prefix for immediate values. 63 /* Use the right prefix for immediate values. */
64 64
65 #define IMM(x) CONCAT1 (__IMMEDIATE_PREFIX__, 65 #define IMM(x) CONCAT1 (__IMMEDIATE_PREFIX__, x)
66 66
67 #define d0 REG (d0) 67 #define d0 REG (d0)
68 #define d1 REG (d1) 68 #define d1 REG (d1)
69 #define d2 REG (d2) 69 #define d2 REG (d2)
70 #define d3 REG (d3) 70 #define d3 REG (d3)
71 #define d4 REG (d4) 71 #define d4 REG (d4)
72 #define d5 REG (d5) 72 #define d5 REG (d5)
73 #define d6 REG (d6) 73 #define d6 REG (d6)
74 #define d7 REG (d7) 74 #define d7 REG (d7)
75 #define a0 REG (a0) 75 #define a0 REG (a0)
76 #define a1 REG (a1) 76 #define a1 REG (a1)
77 #define a2 REG (a2) 77 #define a2 REG (a2)
78 #define a3 REG (a3) 78 #define a3 REG (a3)
79 #define a4 REG (a4) 79 #define a4 REG (a4)
80 #define a5 REG (a5) 80 #define a5 REG (a5)
81 #define a6 REG (a6) 81 #define a6 REG (a6)
82 #define fp REG (fp) 82 #define fp REG (fp)
83 #define sp REG (sp) 83 #define sp REG (sp)
84 84
85 .text 85 .text
86 .proc 86 .proc
87 .globl SYM (__udivsi3) 87 .globl SYM (__udivsi3)
88 SYM (__udivsi3): 88 SYM (__udivsi3):
89 #if !(defined(__mcf5200__) || defined(__mcoldf 89 #if !(defined(__mcf5200__) || defined(__mcoldfire__))
90 movel d2, sp@- 90 movel d2, sp@-
91 movel sp@(12), d1 /* d1 = diviso 91 movel sp@(12), d1 /* d1 = divisor */
92 movel sp@(8), d0 /* d0 = divide 92 movel sp@(8), d0 /* d0 = dividend */
93 93
94 cmpl IMM (0x10000), d1 /* divisor > 94 cmpl IMM (0x10000), d1 /* divisor >= 2 ^ 16 ? */
95 jcc L3 /* then try ne 95 jcc L3 /* then try next algorithm */
96 movel d0, d2 96 movel d0, d2
97 clrw d2 97 clrw d2
98 swap d2 98 swap d2
99 divu d1, d2 /* high quotie 99 divu d1, d2 /* high quotient in lower word */
100 movew d2, d0 /* save high q 100 movew d2, d0 /* save high quotient */
101 swap d0 101 swap d0
102 movew sp@(10), d2 /* get low div 102 movew sp@(10), d2 /* get low dividend + high rest */
103 divu d1, d2 /* low quotien 103 divu d1, d2 /* low quotient */
104 movew d2, d0 104 movew d2, d0
105 jra L6 105 jra L6
106 106
107 L3: movel d1, d2 /* use d2 as d 107 L3: movel d1, d2 /* use d2 as divisor backup */
108 L4: lsrl IMM (1), d1 /* shift divis 108 L4: lsrl IMM (1), d1 /* shift divisor */
109 lsrl IMM (1), d0 /* shift divid 109 lsrl IMM (1), d0 /* shift dividend */
110 cmpl IMM (0x10000), d1 /* still div 110 cmpl IMM (0x10000), d1 /* still divisor >= 2 ^ 16 ? */
111 jcc L4 111 jcc L4
112 divu d1, d0 /* now we have 112 divu d1, d0 /* now we have 16 bit divisor */
113 andl IMM (0xffff), d0 /* mask out d 113 andl IMM (0xffff), d0 /* mask out divisor, ignore remainder */
114 114
115 /* Multiply the 16 bit tentative quotient with 115 /* Multiply the 16 bit tentative quotient with the 32 bit divisor. Because of
116 the operand ranges, this might give a 33 bi 116 the operand ranges, this might give a 33 bit product. If this product is
117 greater than the dividend, the tentative qu 117 greater than the dividend, the tentative quotient was too large. */
118 movel d2, d1 118 movel d2, d1
119 mulu d0, d1 /* low part, 3 119 mulu d0, d1 /* low part, 32 bits */
120 swap d2 120 swap d2
121 mulu d0, d2 /* high part, 121 mulu d0, d2 /* high part, at most 17 bits */
122 swap d2 /* align high 122 swap d2 /* align high part with low part */
123 tstw d2 /* high part 1 123 tstw d2 /* high part 17 bits? */
124 jne L5 /* if 17 bits, 124 jne L5 /* if 17 bits, quotient was too large */
125 addl d2, d1 /* add parts * 125 addl d2, d1 /* add parts */
126 jcs L5 /* if sum is 3 126 jcs L5 /* if sum is 33 bits, quotient was too large */
127 cmpl sp@(8), d1 /* compare the 127 cmpl sp@(8), d1 /* compare the sum with the dividend */
128 jls L6 /* if sum > di 128 jls L6 /* if sum > dividend, quotient was too large */
129 L5: subql IMM (1), d0 /* adjust quot 129 L5: subql IMM (1), d0 /* adjust quotient */
130 130
131 L6: movel sp@+, d2 131 L6: movel sp@+, d2
132 rts 132 rts
133 133
134 #else /* __mcf5200__ || __mcoldfire__ */ 134 #else /* __mcf5200__ || __mcoldfire__ */
135 135
136 /* Coldfire implementation of non-restoring di 136 /* Coldfire implementation of non-restoring division algorithm from
137 Hennessy & Patterson, Appendix A. */ 137 Hennessy & Patterson, Appendix A. */
138 link a6,IMM (-12) 138 link a6,IMM (-12)
139 moveml d2-d4,sp@ 139 moveml d2-d4,sp@
140 movel a6@(8),d0 140 movel a6@(8),d0
141 movel a6@(12),d1 141 movel a6@(12),d1
142 clrl d2 | clear p 142 clrl d2 | clear p
143 moveq IMM (31),d4 143 moveq IMM (31),d4
144 L1: addl d0,d0 | shift reg pa 144 L1: addl d0,d0 | shift reg pair (p,a) one bit left
145 addxl d2,d2 145 addxl d2,d2
146 movl d2,d3 | subtract b f 146 movl d2,d3 | subtract b from p, store in tmp.
147 subl d1,d3 147 subl d1,d3
148 jcs L2 | if no carry, 148 jcs L2 | if no carry,
149 bset IMM (0),d0 | set the low 149 bset IMM (0),d0 | set the low order bit of a to 1,
150 movl d3,d2 | and store tm 150 movl d3,d2 | and store tmp in p.
151 L2: subql IMM (1),d4 151 L2: subql IMM (1),d4
152 jcc L1 152 jcc L1
153 moveml sp@,d2-d4 | restore data 153 moveml sp@,d2-d4 | restore data registers
154 unlk a6 | and return 154 unlk a6 | and return
155 rts 155 rts
156 #endif /* __mcf5200__ || __mcoldfire__ */ 156 #endif /* __mcf5200__ || __mcoldfire__ */
157 EXPORT_SYMBOL(__udivsi3) 157 EXPORT_SYMBOL(__udivsi3)
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