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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 | .text | |
38 | ENTRY(__c6xabi_divi) | |
39 | call .s2 __c6xabi_divu | |
40 | || mv .d2 B3, B5 | |
41 | || cmpgt .l1 0, A4, A1 | |
42 | || cmpgt .l2 0, B4, B1 | |
43 | ||
44 | [A1] neg .l1 A4, A4 | |
45 | || [B1] neg .l2 B4, B4 | |
46 | || xor .s1x A1, B1, A1 | |
47 | [A1] addkpc .s2 _divu_ret, B3, 4 | |
48 | _divu_ret: | |
49 | neg .l1 A4, A4 | |
50 | || mv .l2 B3,B5 | |
51 | || ret .s2 B5 | |
52 | nop 5 | |
53 | ENDPROC(__c6xabi_divi) |