]>
Commit | Line | Data |
---|---|---|
78df0fcb | 1 | /* strlen(str) -- determine the length of the string STR. |
623aac7f | 2 | Copyright (C) 2009, 2010 Free Software Foundation, Inc. |
a152f366 | 3 | Contributed by Ulrich Drepper <drepper@redhat.com>. |
78df0fcb AJ |
4 | This file is part of the GNU C Library. |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public | |
17 | License along with the GNU C Library; if not, write to the Free | |
18 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
19 | 02111-1307 USA. */ | |
20 | ||
21 | #include <sysdep.h> | |
78df0fcb AJ |
22 | |
23 | ||
322e23db | 24 | .text |
a152f366 | 25 | ENTRY(strlen) |
623aac7f L |
26 | xor %rax, %rax |
27 | mov %edi, %ecx | |
28 | and $0x3f, %ecx | |
29 | pxor %xmm0, %xmm0 | |
30 | cmp $0x30, %ecx | |
31 | ja L(next) | |
32 | movdqu (%rdi), %xmm1 | |
a152f366 UD |
33 | pcmpeqb %xmm1, %xmm0 |
34 | pmovmskb %xmm0, %edx | |
623aac7f L |
35 | test %edx, %edx |
36 | jnz L(exit_less16) | |
37 | mov %rdi, %rax | |
38 | and $-16, %rax | |
39 | jmp L(align16_start) | |
40 | L(next): | |
41 | mov %rdi, %rax | |
42 | and $-16, %rax | |
43 | pcmpeqb (%rax), %xmm0 | |
44 | mov $-1, %esi | |
45 | sub %rax, %rcx | |
46 | shl %cl, %esi | |
47 | pmovmskb %xmm0, %edx | |
48 | and %esi, %edx | |
49 | jnz L(exit) | |
50 | L(align16_start): | |
51 | pxor %xmm0, %xmm0 | |
52 | pxor %xmm1, %xmm1 | |
53 | pxor %xmm2, %xmm2 | |
54 | pxor %xmm3, %xmm3 | |
55 | .p2align 4 | |
56 | L(align16_loop): | |
57 | pcmpeqb 16(%rax), %xmm0 | |
58 | pmovmskb %xmm0, %edx | |
59 | test %edx, %edx | |
60 | jnz L(exit16) | |
a152f366 | 61 | |
623aac7f L |
62 | pcmpeqb 32(%rax), %xmm1 |
63 | pmovmskb %xmm1, %edx | |
64 | test %edx, %edx | |
65 | jnz L(exit32) | |
66 | ||
67 | pcmpeqb 48(%rax), %xmm2 | |
68 | pmovmskb %xmm2, %edx | |
69 | test %edx, %edx | |
70 | jnz L(exit48) | |
71 | ||
72 | pcmpeqb 64(%rax), %xmm3 | |
73 | pmovmskb %xmm3, %edx | |
74 | lea 64(%rax), %rax | |
75 | test %edx, %edx | |
76 | jz L(align16_loop) | |
77 | L(exit): | |
78 | sub %rdi, %rax | |
79 | L(exit_less16): | |
80 | bsf %rdx, %rdx | |
81 | add %rdx, %rax | |
82 | ret | |
83 | .p2align 4 | |
84 | L(exit16): | |
85 | sub %rdi, %rax | |
86 | bsf %rdx, %rdx | |
01d26015 | 87 | lea 16(%rdx,%rax), %rax |
623aac7f L |
88 | ret |
89 | .p2align 4 | |
90 | L(exit32): | |
91 | sub %rdi, %rax | |
92 | bsf %rdx, %rdx | |
01d26015 | 93 | lea 32(%rdx,%rax), %rax |
623aac7f L |
94 | ret |
95 | .p2align 4 | |
96 | L(exit48): | |
97 | sub %rdi, %rax | |
98 | bsf %rdx, %rdx | |
01d26015 | 99 | lea 48(%rdx,%rax), %rax |
78df0fcb | 100 | ret |
a152f366 | 101 | END(strlen) |
85dd1003 | 102 | libc_hidden_builtin_def (strlen) |