Commit | Line | Data |
---|---|---|
09831ca7 AJ |
1 | ;; Copyright 2010 Free Software Foundation, Inc. |
2 | ;; Contributed by Bernd Schmidt <bernds@codesourcery.com>. | |
3 | ;; | |
4 | ;; This program is free software; you can redistribute it and/or modify | |
5 | ;; it under the terms of the GNU General Public License as published by | |
6 | ;; the Free Software Foundation; either version 2 of the License, or | |
7 | ;; (at your option) any later version. | |
8 | ;; | |
9 | ;; This program is distributed in the hope that it will be useful, | |
10 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | ;; GNU General Public License for more details. | |
13 | ;; | |
14 | ;; You should have received a copy of the GNU General Public License | |
15 | ;; along with this program; if not, write to the Free Software | |
16 | ;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | ||
18 | #include <linux/linkage.h> | |
19 | ||
20 | ;; ABI considerations for the divide functions | |
21 | ;; The following registers are call-used: | |
22 | ;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5 | |
23 | ;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4 | |
24 | ;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4 | |
25 | ;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4 | |
26 | ;; | |
27 | ;; In our implementation, divu and remu are leaf functions, | |
28 | ;; while both divi and remi call into divu. | |
29 | ;; A0 is not clobbered by any of the functions. | |
30 | ;; divu does not clobber B2 either, which is taken advantage of | |
31 | ;; in remi. | |
32 | ;; divi uses B5 to hold the original return address during | |
33 | ;; the call to divu. | |
34 | ;; remi uses B2 and A5 to hold the input values during the | |
35 | ;; call to divu. It stores B3 in on the stack. | |
36 | ||
37 | ||
38 | .text | |
39 | ||
40 | ENTRY(__c6xabi_remu) | |
41 | ;; The ABI seems designed to prevent these functions calling each other, | |
42 | ;; so we duplicate most of the divsi3 code here. | |
43 | mv .s2x A4, B1 | |
44 | lmbd .l2 1, B4, B1 | |
45 | || [!B1] b .s2 B3 ; RETURN A | |
46 | || [!B1] mvk .d2 1, B4 | |
47 | ||
48 | mv .l1x B1, A7 | |
49 | || shl .s2 B4, B1, B4 | |
50 | ||
51 | cmpltu .l1x A4, B4, A1 | |
52 | [!A1] sub .l1x A4, B4, A4 | |
53 | shru .s2 B4, 1, B4 | |
54 | ||
55 | _remu_loop: | |
56 | cmpgt .l2 B1, 7, B0 | |
57 | || [B1] subc .l1x A4,B4,A4 | |
58 | || [B1] add .s2 -1, B1, B1 | |
59 | ;; RETURN A may happen here (note: must happen before the next branch) | |
60 | [B1] subc .l1x A4,B4,A4 | |
61 | || [B1] add .s2 -1, B1, B1 | |
62 | || [B0] b .s1 _remu_loop | |
63 | [B1] subc .l1x A4,B4,A4 | |
64 | || [B1] add .s2 -1, B1, B1 | |
65 | [B1] subc .l1x A4,B4,A4 | |
66 | || [B1] add .s2 -1, B1, B1 | |
67 | [B1] subc .l1x A4,B4,A4 | |
68 | || [B1] add .s2 -1, B1, B1 | |
69 | [B1] subc .l1x A4,B4,A4 | |
70 | || [B1] add .s2 -1, B1, B1 | |
71 | [B1] subc .l1x A4,B4,A4 | |
72 | || [B1] add .s2 -1, B1, B1 | |
73 | ;; loop backwards branch happens here | |
74 | ||
75 | ret .s2 B3 | |
76 | [B1] subc .l1x A4,B4,A4 | |
77 | || [B1] add .s2 -1, B1, B1 | |
78 | [B1] subc .l1x A4,B4,A4 | |
79 | ||
80 | extu .s1 A4, A7, A4 | |
81 | nop 2 | |
82 | ENDPROC(__c6xabi_remu) |