Aurelien Jacquiot | 09831ca | 2011-10-04 11:15:51 -0400 | [diff] [blame] | 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) |