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