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
|
;; SPDX-License-Identifier: GPL-2.0-or-later
;; Copyright 2010 Free Software Foundation, Inc.
;; Contributed by Bernd Schmidt <bernds@codesourcery.com>.
;;
#include <linux/linkage.h>
;; ABI considerations for the divide functions
;; The following registers are call-used:
;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5
;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4
;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4
;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4
;;
;; In our implementation, divu and remu are leaf functions,
;; while both divi and remi call into divu.
;; A0 is not clobbered by any of the functions.
;; divu does not clobber B2 either, which is taken advantage of
;; in remi.
;; divi uses B5 to hold the original return address during
;; the call to divu.
;; remi uses B2 and A5 to hold the input values during the
;; call to divu. It stores B3 in on the stack.
.text
ENTRY(__c6xabi_remi)
stw .d2t2 B3, *B15--[2]
|| cmpgt .l1 0, A4, A1
|| cmpgt .l2 0, B4, B2
|| mv .s1 A4, A5
|| call .s2 __c6xabi_divu
[A1] neg .l1 A4, A4
|| [B2] neg .l2 B4, B4
|| xor .s2x B2, A1, B0
|| mv .d2 B4, B2
[B0] addkpc .s2 _divu_ret_1, B3, 1
[!B0] addkpc .s2 _divu_ret_2, B3, 1
nop 2
_divu_ret_1:
neg .l1 A4, A4
_divu_ret_2:
ldw .d2t2 *++B15[2], B3
mpy32 .m1x A4, B2, A6
nop 3
ret .s2 B3
sub .l1 A5, A6, A4
nop 4
ENDPROC(__c6xabi_remi)
|
