glibc/sysdeps/x86_64/multiarch/strchr.S

60 lines
1.8 KiB
ArmAsm

/* Multiple versions of strchr
Copyright (C) 2009-2015 Free Software Foundation, Inc.
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, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include <init-arch.h>
/* Define multiple versions only for the definition in libc. */
#if IS_IN (libc)
.text
ENTRY(strchr)
.type strchr, @gnu_indirect_function
cmpl $0, __cpu_features+KIND_OFFSET(%rip)
jne 1f
call __init_cpu_features
1: leaq __strchr_sse2(%rip), %rax
2: testl $bit_Slow_BSF, __cpu_features+FEATURE_OFFSET+index_Slow_BSF(%rip)
jz 3f
leaq __strchr_sse2_no_bsf(%rip), %rax
3: ret
END(strchr)
# undef ENTRY
# define ENTRY(name) \
.type __strchr_sse2, @function; \
.align 16; \
.globl __strchr_sse2; \
.hidden __strchr_sse2; \
__strchr_sse2: cfi_startproc; \
CALL_MCOUNT
# undef END
# define END(name) \
cfi_endproc; .size __strchr_sse2, .-__strchr_sse2
# undef libc_hidden_builtin_def
/* It doesn't make sense to send libc-internal strchr 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_strchr; __GI_strchr = __strchr_sse2
#endif
#include "../strchr.S"