glibc/sysdeps/x86_64/multiarch/memset-erms.S

45 lines
1.3 KiB
ArmAsm

/* memset implement with rep stosb
Copyright (C) 2022-2024 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
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
#if defined USE_MULTIARCH && IS_IN (libc)
.text
ENTRY (__memset_chk_erms)
cmp %RDX_LP, %RCX_LP
jb HIDDEN_JUMPTARGET (__chk_fail)
END (__memset_chk_erms)
/* Only used to measure performance of REP STOSB. */
ENTRY (__memset_erms)
/* Skip zero length. */
test %RDX_LP, %RDX_LP
jz L(stosb_return_zero)
mov %RDX_LP, %RCX_LP
movzbl %sil, %eax
mov %RDI_LP, %RDX_LP
rep stosb
mov %RDX_LP, %RAX_LP
ret
L(stosb_return_zero):
movq %rdi, %rax
ret
END (__memset_erms)
#endif