1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * "memset" implementation for SH4
4 *
5 * Copyright (C) 1999  Niibe Yutaka
6 * Copyright (c) 2009  STMicroelectronics Limited
7 * Author: Stuart Menefy <stuart.menefy:st.com>
8 */
9
10/*
11 *            void *memset(void *s, int c, size_t n);
12 */
13
14#include <linux/linkage.h>
15
16ENTRY(memset)
17	mov	#12,r0
18	add	r6,r4
19	cmp/gt	r6,r0
20	bt/s	40f		! if it's too small, set a byte at once
21	 mov	r4,r0
22	and	#3,r0
23	cmp/eq	#0,r0
24	bt/s	2f		! It's aligned
25	 sub	r0,r6
261:
27	dt	r0
28	bf/s	1b
29	 mov.b	r5,@-r4
302:				! make VVVV
31	extu.b	r5,r5
32	swap.b	r5,r0		!   V0
33	or	r0,r5		!   VV
34	swap.w	r5,r0		! VV00
35	or	r0,r5		! VVVV
36
37	! Check if enough bytes need to be copied to be worth the big loop
38	mov	#0x40, r0	! (MT)
39	cmp/gt	r6,r0		! (MT)  64 > len => slow loop
40
41	bt/s	22f
42	 mov	r6,r0
43
44	! align the dst to the cache block size if necessary
45	mov	r4, r3
46	mov	#~(0x1f), r1
47
48	and	r3, r1
49	cmp/eq	r3, r1
50
51	bt/s	11f		! dst is already aligned
52	 sub	r1, r3		! r3-r1 -> r3
53	shlr2	r3		! number of loops
54
5510:	mov.l	r5,@-r4
56	dt	r3
57	bf/s	10b
58	 add	#-4, r6
59
6011:	! dst is 32byte aligned
61	mov	r6,r2
62	mov	#-5,r0
63	shld	r0,r2		! number of loops
64
65	add	#-32, r4
66	mov	r5, r0
6712:
68	movca.l	r0,@r4
69	mov.l	r5,@(4, r4)
70	mov.l	r5,@(8, r4)
71	mov.l	r5,@(12,r4)
72	mov.l	r5,@(16,r4)
73	mov.l	r5,@(20,r4)
74	add	#-0x20, r6
75	mov.l	r5,@(24,r4)
76	dt	r2
77	mov.l	r5,@(28,r4)
78	bf/s	12b
79	 add	#-32, r4
80
81	add	#32, r4
82	mov	#8, r0
83	cmp/ge	r0, r6
84	bf	40f
85
86	mov	r6,r0
8722:
88	shlr2	r0
89	shlr	r0		! r0 = r6 >> 3
903:
91	dt	r0
92	mov.l	r5,@-r4		! set 8-byte at once
93	bf/s	3b
94	 mov.l	r5,@-r4
95	!
96	mov	#7,r0
97	and	r0,r6
98
99	! fill bytes (length may be zero)
10040:	tst	r6,r6
101	bt	5f
1024:
103	dt	r6
104	bf/s	4b
105	 mov.b	r5,@-r4
1065:
107	rts
108	 mov	r4,r0
109