1 /* SPDX-License-Identifier: GPL-2.0 */ !! 1 /* strlen.S: Sparc optimized strlen code
2 /* $Id: strlen.S,v 1.2 2001/06/29 14:07:15 gni !! 2 * Hand optimized from GNU libc's strlen
3 * !! 3 * Copyright (C) 1991,1996 Free Software Foundation
4 * "strlen" implementation of SuperH !! 4 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
5 * !! 5 * Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
6 * Copyright (C) 1999 Kaz Kojima <<
7 * <<
8 */ 6 */
9 7
10 /* size_t strlen (const char *s) */ !! 8 #include <asm/cprefix.h>
11 9
12 #include <linux/linkage.h> !! 10 #define LO_MAGIC 0x01010101
13 ENTRY(strlen) !! 11 #define HI_MAGIC 0x80808080
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 <<
26 mov.b @r4+,r1 <<
27 tst r1,r1 <<
28 bt 8f <<
29 add #1,r2 <<
30 <<
31 mov.b @r4+,r1 <<
32 tst r1,r1 <<
33 bt 8f <<
34 add #1,r2 <<
35 <<
36 mov.b @r4+,r1 <<
37 tst r1,r1 <<
38 bt 8f <<
39 add #1,r2 <<
40 12
>> 13 0:
>> 14 ldub [%o0], %o5
>> 15 cmp %o5, 0
>> 16 be 1f
>> 17 add %o0, 1, %o0
>> 18 andcc %o0, 3, %g0
>> 19 be 4f
>> 20 or %o4, %lo(HI_MAGIC), %o3
>> 21 ldub [%o0], %o5
>> 22 cmp %o5, 0
>> 23 be 2f
>> 24 add %o0, 1, %o0
>> 25 andcc %o0, 3, %g0
>> 26 be 5f
>> 27 sethi %hi(LO_MAGIC), %o4
>> 28 ldub [%o0], %o5
>> 29 cmp %o5, 0
>> 30 be 3f
>> 31 add %o0, 1, %o0
>> 32 b 8f
>> 33 or %o4, %lo(LO_MAGIC), %o2
41 1: 34 1:
42 mov #0,r3 !! 35 retl
>> 36 mov 0, %o0
43 2: 37 2:
44 mov.l @r4+,r1 !! 38 retl
45 cmp/str r3,r1 !! 39 mov 1, %o0
46 bf/s 2b !! 40 3:
47 add #4,r2 !! 41 retl
48 !! 42 mov 2, %o0
49 add #-4,r2 !! 43
50 #ifndef __LITTLE_ENDIAN__ !! 44 .align 4
51 swap.b r1,r1 !! 45 .global C_LABEL(strlen)
52 swap.w r1,r1 !! 46 C_LABEL(strlen):
53 swap.b r1,r1 !! 47 mov %o0, %o1
54 #endif !! 48 andcc %o0, 3, %g0
55 extu.b r1,r0 !! 49 bne 0b
56 tst r0,r0 !! 50 sethi %hi(HI_MAGIC), %o4
57 bt/s 8f !! 51 or %o4, %lo(HI_MAGIC), %o3
58 shlr8 r1 !! 52 4:
59 add #1,r2 !! 53 sethi %hi(LO_MAGIC), %o4
60 extu.b r1,r0 !! 54 5:
61 tst r0,r0 !! 55 or %o4, %lo(LO_MAGIC), %o2
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: 56 8:
70 rts !! 57 ld [%o0], %o5
71 mov r2,r0 !! 58 2:
>> 59 sub %o5, %o2, %o4
>> 60 andcc %o4, %o3, %g0
>> 61 be 8b
>> 62 add %o0, 4, %o0
>> 63
>> 64 /* Check every byte. */
>> 65 srl %o5, 24, %g5
>> 66 andcc %g5, 0xff, %g0
>> 67 be 1f
>> 68 add %o0, -4, %o4
>> 69 srl %o5, 16, %g5
>> 70 andcc %g5, 0xff, %g0
>> 71 be 1f
>> 72 add %o4, 1, %o4
>> 73 srl %o5, 8, %g5
>> 74 andcc %g5, 0xff, %g0
>> 75 be 1f
>> 76 add %o4, 1, %o4
>> 77 andcc %o5, 0xff, %g0
>> 78 bne,a 2b
>> 79 ld [%o0], %o5
>> 80 add %o4, 1, %o4
>> 81 1:
>> 82 retl
>> 83 sub %o4, %o1, %o0
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