1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* $Id: strlen.S,v 1.2 2001/06/29 14:07:15 gni !! 2 /* strlen.S: Sparc optimized strlen code
3 * !! 3 * Hand optimized from GNU libc's strlen
4 * "strlen" implementation of SuperH !! 4 * Copyright (C) 1991,1996 Free Software Foundation
5 * !! 5 * Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net)
6 * Copyright (C) 1999 Kaz Kojima !! 6 * Copyright (C) 1996, 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
7 * <<
8 */ 7 */
9 8
10 /* size_t strlen (const char *s) */ !! 9 #include <linux/export.h>
11 <<
12 #include <linux/linkage.h> 10 #include <linux/linkage.h>
13 ENTRY(strlen) !! 11 #include <asm/asm.h>
14 mov r4,r0 <<
15 and #3,r0 <<
16 tst r0,r0 <<
17 bt/s 1f <<
18 mov #0,r2 <<
19 <<
20 add #-1,r0 <<
21 shll2 r0 <<
22 shll r0 <<
23 braf r0 <<
24 nop <<
25 12
26 mov.b @r4+,r1 !! 13 #define LO_MAGIC 0x01010101
27 tst r1,r1 !! 14 #define HI_MAGIC 0x80808080
28 bt 8f <<
29 add #1,r2 <<
30 15
31 mov.b @r4+,r1 !! 16 .text
32 tst r1,r1 !! 17 ENTRY(strlen)
33 bt 8f !! 18 mov %o0, %o1
34 add #1,r2 !! 19 andcc %o0, 3, %g0
35 !! 20 BRANCH32(be, pt, 9f)
36 mov.b @r4+,r1 !! 21 sethi %hi(HI_MAGIC), %o4
37 tst r1,r1 !! 22 ldub [%o0], %o5
38 bt 8f !! 23 BRANCH_REG_ZERO(pn, %o5, 11f)
39 add #1,r2 !! 24 add %o0, 1, %o0
40 !! 25 andcc %o0, 3, %g0
41 1: !! 26 BRANCH32(be, pn, 4f)
42 mov #0,r3 !! 27 or %o4, %lo(HI_MAGIC), %o3
43 2: !! 28 ldub [%o0], %o5
44 mov.l @r4+,r1 !! 29 BRANCH_REG_ZERO(pn, %o5, 12f)
45 cmp/str r3,r1 !! 30 add %o0, 1, %o0
46 bf/s 2b !! 31 andcc %o0, 3, %g0
47 add #4,r2 !! 32 BRANCH32(be, pt, 5f)
48 !! 33 sethi %hi(LO_MAGIC), %o4
49 add #-4,r2 !! 34 ldub [%o0], %o5
50 #ifndef __LITTLE_ENDIAN__ !! 35 BRANCH_REG_ZERO(pn, %o5, 13f)
51 swap.b r1,r1 !! 36 add %o0, 1, %o0
52 swap.w r1,r1 !! 37 BRANCH32(ba, pt, 8f)
53 swap.b r1,r1 !! 38 or %o4, %lo(LO_MAGIC), %o2
54 #endif !! 39 9:
55 extu.b r1,r0 !! 40 or %o4, %lo(HI_MAGIC), %o3
56 tst r0,r0 !! 41 4:
57 bt/s 8f !! 42 sethi %hi(LO_MAGIC), %o4
58 shlr8 r1 !! 43 5:
59 add #1,r2 !! 44 or %o4, %lo(LO_MAGIC), %o2
60 extu.b r1,r0 <<
61 tst r0,r0 <<
62 bt/s 8f <<
63 shlr8 r1 <<
64 add #1,r2 <<
65 extu.b r1,r0 <<
66 tst r0,r0 <<
67 bt 8f <<
68 add #1,r2 <<
69 8: 45 8:
70 rts !! 46 ld [%o0], %o5
71 mov r2,r0 !! 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)
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