sysdeps/i386/i686/multiarch/strlen.S

   1 /* Multiple versions of strlen
   2    All versions must be listed in ifunc-impl-list.c.
   3    Copyright (C) 2009-2016 Free Software Foundation, Inc.
   4    Contributed by Intel Corporation.
   5    This file is part of the GNU C Library.
   6
   7    The GNU C Library is free software; you can redistribute it and/or
   8    modify it under the terms of the GNU Lesser General Public
   9    License as published by the Free Software Foundation; either
  10    version 2.1 of the License, or (at your option) any later version.
  11
  12    The GNU C Library is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    Lesser General Public License for more details.
  16
  17    You should have received a copy of the GNU Lesser General Public
  18    License along with the GNU C Library; if not, see
  19    <http://www.gnu.org/licenses/>.  */
  20
  21 #include <sysdep.h>
  22 #include <init-arch.h>
  23
  24 /* Define multiple versions only for the definition in libc and for the
  25    DSO.  In static binaries, we need strlen before the initialization
  26    happened.  */
  27 #if defined SHARED && IS_IN (libc)
  28         .text
  29 ENTRY(strlen)
  30         .type   strlen, @gnu_indirect_function
  31         LOAD_GOT_AND_RTLD_GLOBAL_RO
  32         LOAD_FUNC_GOT_EAX (__strlen_ia32)
  33         HAS_CPU_FEATURE (SSE2)
  34         jz      2f
  35         LOAD_FUNC_GOT_EAX (__strlen_sse2_bsf)
  36         HAS_ARCH_FEATURE (Slow_BSF)
  37         jz      2f
  38         LOAD_FUNC_GOT_EAX (__strlen_sse2)
  39 2:      ret
  40 END(strlen)
  41
  42 # undef ENTRY
  43 # define ENTRY(name) \
  44         .type __strlen_ia32, @function; \
  45         .globl __strlen_ia32; \
  46         .p2align 4; \
  47         __strlen_ia32: cfi_startproc; \
  48         CALL_MCOUNT
  49 # undef END
  50 # define END(name) \
  51         cfi_endproc; .size __strlen_ia32, .-__strlen_ia32
  52 # undef libc_hidden_builtin_def
  53 /* IFUNC doesn't work with the hidden functions in shared library since
  54    they will be called without setting up EBX needed for PLT which is
  55    used by IFUNC.  */
  56 # define libc_hidden_builtin_def(name) \
  57         .globl __GI_strlen; __GI_strlen = __strlen_ia32
  58 #endif
  59
  60 #include "../../i586/strlen.S"