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Aurelien Jacquiot09831ca2011-10-04 11:15:51 -04001;; 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
38ENTRY(__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
53ENDPROC(__c6xabi_divi)