1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
| ;; Copyright 2011 Free Software Foundation, Inc.
| ;; Contributed by Bernd Schmidt <bernds@codesourcery.com>.
| ;;
| ;; This program is free software; you can redistribute it and/or modify
| ;; it under the terms of the GNU General Public License as published by
| ;; the Free Software Foundation; either version 2 of the License, or
| ;; (at your option) any later version.
| ;;
| ;; This program is distributed in the hope that it will be useful,
| ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
| ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
| ;; GNU General Public License for more details.
| ;;
| ;; You should have received a copy of the GNU General Public License
| ;; along with this program; if not, write to the Free Software
| ;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
| #include <linux/linkage.h>
|
| .text
| ENTRY(__c6xabi_divremu)
| ;; We use a series of up to 31 subc instructions. First, we find
| ;; out how many leading zero bits there are in the divisor. This
| ;; gives us both a shift count for aligning (shifting) the divisor
| ;; to the, and the number of times we have to execute subc.
|
| ;; At the end, we have both the remainder and most of the quotient
| ;; in A4. The top bit of the quotient is computed first and is
| ;; placed in A2.
|
| ;; Return immediately if the dividend is zero. Setting B4 to 1
| ;; is a trick to allow us to leave the following insns in the jump
| ;; delay slot without affecting the result.
| mv .s2x A4, B1
|
| [b1] lmbd .l2 1, B4, B1
| ||[!b1] b .s2 B3 ; RETURN A
| ||[!b1] mvk .d2 1, B4
|
| ||[!b1] zero .s1 A5
| mv .l1x B1, A6
| || shl .s2 B4, B1, B4
|
| ;; The loop performs a maximum of 28 steps, so we do the
| ;; first 3 here.
| cmpltu .l1x A4, B4, A2
| [!A2] sub .l1x A4, B4, A4
| || shru .s2 B4, 1, B4
| || xor .s1 1, A2, A2
|
| shl .s1 A2, 31, A2
| || [b1] subc .l1x A4,B4,A4
| || [b1] add .s2 -1, B1, B1
| [b1] subc .l1x A4,B4,A4
| || [b1] add .s2 -1, B1, B1
|
| ;; RETURN A may happen here (note: must happen before the next branch)
| __divremu0:
| cmpgt .l2 B1, 7, B0
| || [b1] subc .l1x A4,B4,A4
| || [b1] add .s2 -1, B1, B1
| [b1] subc .l1x A4,B4,A4
| || [b1] add .s2 -1, B1, B1
| || [b0] b .s1 __divremu0
| [b1] subc .l1x A4,B4,A4
| || [b1] add .s2 -1, B1, B1
| [b1] subc .l1x A4,B4,A4
| || [b1] add .s2 -1, B1, B1
| [b1] subc .l1x A4,B4,A4
| || [b1] add .s2 -1, B1, B1
| [b1] subc .l1x A4,B4,A4
| || [b1] add .s2 -1, B1, B1
| [b1] subc .l1x A4,B4,A4
| || [b1] add .s2 -1, B1, B1
| ;; loop backwards branch happens here
|
| ret .s2 B3
| || mvk .s1 32, A1
| sub .l1 A1, A6, A6
| || extu .s1 A4, A6, A5
| shl .s1 A4, A6, A4
| shru .s1 A4, 1, A4
| || sub .l1 A6, 1, A6
| or .l1 A2, A4, A4
| shru .s1 A4, A6, A4
| nop
| ENDPROC(__c6xabi_divremu)
|
|
