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
26ENTRY(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)
58libc_hidden_builtin_def (strlen)
59

source code of glibc/sysdeps/alpha/alphaev67/strlen.S