sysdeps/x86_64/multiarch/strnlen.S

   1 /* multiple version of strnlen
   2    Copyright (C) 2011 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <sysdep.h>
  20 #include <init-arch.h>
  21
  22
  23 /* Define multiple versions only for the definition in libc.  */
  24 #ifndef NOT_IN_libc
  25
  26         .text
  27 ENTRY(__strnlen)
  28         .type   __strnlen, @gnu_indirect_function
  29         cmpl    $0, __cpu_features+KIND_OFFSET(%rip)
  30         jne     1f
  31         call    __init_cpu_features
  32 1:      leaq    __strnlen_sse2(%rip), %rax
  33         testl   $bit_Slow_BSF, __cpu_features+FEATURE_OFFSET+index_Slow_BSF(%rip)
  34         jz      2f
  35         leaq    __strnlen_sse2_no_bsf(%rip), %rax
  36 2:      ret
  37 END(__strnlen)
  38
  39 # undef ENTRY
  40 # define ENTRY(name) \
  41         .type __strnlen_sse2, @function; \
  42         .align 16; \
  43         __strnlen_sse2: cfi_startproc; \
  44         CALL_MCOUNT
  45 # undef END
  46 # define END(name) \
  47         cfi_endproc; .size __strnlen_sse2, .-__strnlen_sse2
  48
  49 # undef libc_hidden_def
  50 # define libc_hidden_def(name) \
  51         .globl __GI_strnlen; __GI_strnlen = __strnlen_sse2
  52 #endif
  53
  54 #include "../strnlen.S"