1;; SPDX-License-Identifier: GPL-2.0-or-later
2;;  Copyright 2010  Free Software Foundation, Inc.
3;;  Contributed by Bernd Schmidt <bernds@codesourcery.com>.
4;;
5
6#include <linux/linkage.h>
7
8	;; ABI considerations for the divide functions
9	;; The following registers are call-used:
10	;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5
11	;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4
12	;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4
13	;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4
14	;;
15	;; In our implementation, divu and remu are leaf functions,
16	;; while both divi and remi call into divu.
17	;; A0 is not clobbered by any of the functions.
18	;; divu does not clobber B2 either, which is taken advantage of
19	;; in remi.
20	;; divi uses B5 to hold the original return address during
21	;; the call to divu.
22	;; remi uses B2 and A5 to hold the input values during the
23	;; call to divu.  It stores B3 in on the stack.
24
25
26	.text
27
28ENTRY(__c6xabi_remu)
29	;; The ABI seems designed to prevent these functions calling each other,
30	;; so we duplicate most of the divsi3 code here.
31	 mv	.s2x	A4, B1
32	 lmbd	.l2	1, B4, B1
33|| [!B1] b	.s2	B3	; RETURN A
34|| [!B1] mvk	.d2	1, B4
35
36	 mv	.l1x	B1, A7
37||	 shl	.s2	B4, B1, B4
38
39	 cmpltu	.l1x	A4, B4, A1
40   [!A1] sub	.l1x	A4, B4, A4
41	 shru	.s2	B4, 1, B4
42
43_remu_loop:
44	 cmpgt	.l2	B1, 7, B0
45|| [B1]	 subc	.l1x	A4,B4,A4
46|| [B1]	 add	.s2	-1, B1, B1
47	;; RETURN A may happen here (note: must happen before the next branch)
48   [B1]	 subc	.l1x	A4,B4,A4
49|| [B1]	 add	.s2	-1, B1, B1
50|| [B0]	 b	.s1	_remu_loop
51   [B1]	 subc	.l1x	A4,B4,A4
52|| [B1]	 add	.s2	-1, B1, B1
53   [B1]	 subc	.l1x	A4,B4,A4
54|| [B1]	 add	.s2	-1, B1, B1
55   [B1]	 subc	.l1x	A4,B4,A4
56|| [B1]	 add	.s2	-1, B1, B1
57   [B1]	 subc	.l1x	A4,B4,A4
58|| [B1]	 add	.s2	-1, B1, B1
59   [B1]	 subc	.l1x	A4,B4,A4
60|| [B1]	 add	.s2	-1, B1, B1
61	;; loop backwards branch happens here
62
63	 ret	.s2	B3
64   [B1]	 subc	.l1x	A4,B4,A4
65|| [B1]	 add	.s2	-1, B1, B1
66   [B1]	 subc	.l1x	A4,B4,A4
67
68	 extu	.s1	A4, A7, A4
69	 nop	2
70ENDPROC(__c6xabi_remu)
71