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 | |
16 | ENTRY(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 |
26 | 1: |
27 | dt r0 |
28 | bf/s 1b |
29 | mov.b r5,@-r4 |
30 | 2: ! 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 | |
55 | 10: mov.l r5,@-r4 |
56 | dt r3 |
57 | bf/s 10b |
58 | add #-4, r6 |
59 | |
60 | 11: ! 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 |
67 | 12: |
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 |
87 | 22: |
88 | shlr2 r0 |
89 | shlr r0 ! r0 = r6 >> 3 |
90 | 3: |
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) |
100 | 40: tst r6,r6 |
101 | bt 5f |
102 | 4: |
103 | dt r6 |
104 | bf/s 4b |
105 | mov.b r5,@-r4 |
106 | 5: |
107 | rts |
108 | mov r4,r0 |
109 | |