1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* strlen.S: Sparc optimized strlen code |
3 | * Hand optimized from GNU libc's strlen |
4 | * Copyright (C) 1991,1996 Free Software Foundation |
5 | * Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net) |
6 | * Copyright (C) 1996, 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) |
7 | */ |
8 | |
9 | #include <linux/export.h> |
10 | #include <linux/linkage.h> |
11 | #include <asm/asm.h> |
12 | |
13 | #define LO_MAGIC 0x01010101 |
14 | #define HI_MAGIC 0x80808080 |
15 | |
16 | .text |
17 | ENTRY(strlen) |
18 | mov %o0, %o1 |
19 | andcc %o0, 3, %g0 |
20 | BRANCH32(be, pt, 9f) |
21 | sethi %hi(HI_MAGIC), %o4 |
22 | ldub [%o0], %o5 |
23 | BRANCH_REG_ZERO(pn, %o5, 11f) |
24 | add %o0, 1, %o0 |
25 | andcc %o0, 3, %g0 |
26 | BRANCH32(be, pn, 4f) |
27 | or %o4, %lo(HI_MAGIC), %o3 |
28 | ldub [%o0], %o5 |
29 | BRANCH_REG_ZERO(pn, %o5, 12f) |
30 | add %o0, 1, %o0 |
31 | andcc %o0, 3, %g0 |
32 | BRANCH32(be, pt, 5f) |
33 | sethi %hi(LO_MAGIC), %o4 |
34 | ldub [%o0], %o5 |
35 | BRANCH_REG_ZERO(pn, %o5, 13f) |
36 | add %o0, 1, %o0 |
37 | BRANCH32(ba, pt, 8f) |
38 | or %o4, %lo(LO_MAGIC), %o2 |
39 | 9: |
40 | or %o4, %lo(HI_MAGIC), %o3 |
41 | 4: |
42 | sethi %hi(LO_MAGIC), %o4 |
43 | 5: |
44 | or %o4, %lo(LO_MAGIC), %o2 |
45 | 8: |
46 | ld [%o0], %o5 |
47 | 2: |
48 | sub %o5, %o2, %o4 |
49 | andcc %o4, %o3, %g0 |
50 | BRANCH32(be, pt, 8b) |
51 | add %o0, 4, %o0 |
52 | |
53 | /* Check every byte. */ |
54 | srl %o5, 24, %g7 |
55 | andcc %g7, 0xff, %g0 |
56 | BRANCH32(be, pn, 1f) |
57 | add %o0, -4, %o4 |
58 | srl %o5, 16, %g7 |
59 | andcc %g7, 0xff, %g0 |
60 | BRANCH32(be, pn, 1f) |
61 | add %o4, 1, %o4 |
62 | srl %o5, 8, %g7 |
63 | andcc %g7, 0xff, %g0 |
64 | BRANCH32(be, pn, 1f) |
65 | add %o4, 1, %o4 |
66 | andcc %o5, 0xff, %g0 |
67 | BRANCH32_ANNUL(bne, pt, 2b) |
68 | ld [%o0], %o5 |
69 | add %o4, 1, %o4 |
70 | 1: |
71 | retl |
72 | sub %o4, %o1, %o0 |
73 | 11: |
74 | retl |
75 | mov 0, %o0 |
76 | 12: |
77 | retl |
78 | mov 1, %o0 |
79 | 13: |
80 | retl |
81 | mov 2, %o0 |
82 | ENDPROC(strlen) |
83 | EXPORT_SYMBOL(strlen) |
84 | |