/* strlen(str) -- determine the length of the string STR. Copyright (C) 2009 Free Software Foundation, Inc. Contributed by Ulrich Drepper . This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include .text ENTRY(strlen) movq %rdi, %rcx movq %rdi, %r8 andq $~15, %rdi pxor %xmm1, %xmm1 orl $0xffffffff, %esi movdqa (%rdi), %xmm0 subq %rdi, %rcx leaq 16(%rdi), %rdi pcmpeqb %xmm1, %xmm0 shl %cl, %esi pmovmskb %xmm0, %edx xorl %eax, %eax negq %r8 andl %esi, %edx jnz 1f 2: movdqa (%rdi), %xmm0 leaq 16(%rdi), %rdi pcmpeqb %xmm1, %xmm0 pmovmskb %xmm0, %edx testl %edx, %edx jz 2b 1: leaq -16(%rdi,%r8), %rdi bsfl %edx, %eax addq %rdi, %rax ret END(strlen) libc_hidden_builtin_def (strlen)