blob: ed9a763368cd4f54632e2ad6e40472d53a3f889c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* strlen.S: Sparc optimized strlen code
2 * Hand optimized from GNU libc's strlen
3 * Copyright (C) 1991,1996 Free Software Foundation
4 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
6 */
7
8#define LO_MAGIC 0x01010101
9#define HI_MAGIC 0x80808080
10
110:
12 ldub [%o0], %o5
13 cmp %o5, 0
14 be 1f
15 add %o0, 1, %o0
16 andcc %o0, 3, %g0
17 be 4f
18 or %o4, %lo(HI_MAGIC), %o3
19 ldub [%o0], %o5
20 cmp %o5, 0
21 be 2f
22 add %o0, 1, %o0
23 andcc %o0, 3, %g0
24 be 5f
25 sethi %hi(LO_MAGIC), %o4
26 ldub [%o0], %o5
27 cmp %o5, 0
28 be 3f
29 add %o0, 1, %o0
30 b 8f
31 or %o4, %lo(LO_MAGIC), %o2
321:
33 retl
34 mov 0, %o0
352:
36 retl
37 mov 1, %o0
383:
39 retl
40 mov 2, %o0
41
42 .align 4
43 .global strlen
44strlen:
45 mov %o0, %o1
46 andcc %o0, 3, %g0
47 bne 0b
48 sethi %hi(HI_MAGIC), %o4
49 or %o4, %lo(HI_MAGIC), %o3
504:
51 sethi %hi(LO_MAGIC), %o4
525:
53 or %o4, %lo(LO_MAGIC), %o2
548:
55 ld [%o0], %o5
562:
57 sub %o5, %o2, %o4
58 andcc %o4, %o3, %g0
59 be 8b
60 add %o0, 4, %o0
61
62 /* Check every byte. */
63 srl %o5, 24, %g5
64 andcc %g5, 0xff, %g0
65 be 1f
66 add %o0, -4, %o4
67 srl %o5, 16, %g5
68 andcc %g5, 0xff, %g0
69 be 1f
70 add %o4, 1, %o4
71 srl %o5, 8, %g5
72 andcc %g5, 0xff, %g0
73 be 1f
74 add %o4, 1, %o4
75 andcc %o5, 0xff, %g0
76 bne,a 2b
77 ld [%o0], %o5
78 add %o4, 1, %o4
791:
80 retl
81 sub %o4, %o1, %o0