1 | /* Copyright (C) 2000-2022 Free Software Foundation, Inc. |
2 | This file is part of the GNU C Library. |
3 | |
4 | The GNU C Library is free software; you can redistribute it and/or |
5 | modify it under the terms of the GNU Lesser General Public |
6 | License as published by the Free Software Foundation; either |
7 | version 2.1 of the License, or (at your option) any later version. |
8 | |
9 | The GNU C Library is distributed in the hope that it will be useful, |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
12 | Lesser General Public License for more details. |
13 | |
14 | You should have received a copy of the GNU Lesser General Public |
15 | License along with the GNU C Library. If not, see |
16 | <https://www.gnu.org/licenses/>. */ |
17 | |
18 | /* Finds length of a 0-terminated string. */ |
19 | |
20 | #include <sysdep.h> |
21 | |
22 | .arch ev6 |
23 | .set noreorder |
24 | .set noat |
25 | |
26 | ENTRY(strlen) |
27 | #ifdef PROF |
28 | ldgp gp, 0(pv) |
29 | lda AT, _mcount |
30 | jsr AT, (AT), _mcount |
31 | .prologue 1 |
32 | #else |
33 | .prologue 0 |
34 | #endif |
35 | |
36 | ldq_u $1, 0($16) # L : load first quadword ($16 may be misaligned) |
37 | lda $2, -1($31) # E : |
38 | insqh $2, $16, $2 # U : |
39 | andnot $16, 7, $0 # E : |
40 | |
41 | or $2, $1, $1 # E : |
42 | cmpbge $31, $1, $2 # E : $2 <- bitmask: bit i == 1 <==> i-th byte == 0 |
43 | nop # E : |
44 | bne $2, $found # U : |
45 | |
46 | $loop: ldq $1, 8($0) # L : |
47 | addq $0, 8, $0 # E : addr += 8 |
48 | cmpbge $31, $1, $2 # E : |
49 | beq $2, $loop # U : |
50 | |
51 | $found: |
52 | cttz $2, $3 # U0 : |
53 | addq $0, $3, $0 # E : |
54 | subq $0, $16, $0 # E : |
55 | ret $31, ($26) # L0 : |
56 | |
57 | END(strlen) |
58 | libc_hidden_builtin_def (strlen) |
59 | |