| /* strlen(str) -- determine the length of the string STR. |
| Copyright (C) 2009, 2010 Free Software Foundation, Inc. |
| Contributed by Ulrich Drepper <drepper@redhat.com>. |
| 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 <sysdep.h> |
| #include <init-arch.h> |
| |
| |
| /* Define multiple versions only for the definition in libc and for |
| the DSO. In static binaries we need strlen before the initialization |
| happened. */ |
| #if defined SHARED && !defined NOT_IN_libc |
| .text |
| ENTRY(strlen) |
| .type strlen, @gnu_indirect_function |
| cmpl $0, __cpu_features+KIND_OFFSET(%rip) |
| jne 1f |
| call __init_cpu_features |
| 1: leaq __strlen_sse2(%rip), %rax |
| testl $bit_SSE4_2, __cpu_features+CPUID_OFFSET+index_SSE4_2(%rip) |
| jz 2f |
| leaq __strlen_sse42(%rip), %rax |
| ret |
| 2: testl $bit_Slow_BSF, __cpu_features+FEATURE_OFFSET+index_Slow_BSF(%rip) |
| jz 3f |
| leaq __strlen_no_bsf(%rip), %rax |
| 3: ret |
| END(strlen) |
| |
| # undef ENTRY |
| # define ENTRY(name) \ |
| .type __strlen_sse2, @function; \ |
| .align 16; \ |
| __strlen_sse2: cfi_startproc; \ |
| CALL_MCOUNT |
| # undef END |
| # define END(name) \ |
| cfi_endproc; .size __strlen_sse2, .-__strlen_sse2 |
| # undef libc_hidden_builtin_def |
| /* It doesn't make sense to send libc-internal strlen calls through a PLT. |
| The speedup we get from using SSE4.2 instruction is likely eaten away |
| by the indirect call in the PLT. */ |
| # define libc_hidden_builtin_def(name) \ |
| .globl __GI_strlen; __GI_strlen = __strlen_sse2 |
| #endif |
| |
| #include "../strlen.S" |
