glibc/sysdeps/x86_64/multiarch/dl-symbol-redir-ifunc.h
Adhemerval Zanella 5355f9ca7b elf: Remove -fno-tree-loop-distribute-patterns usage on dl-support
Besides the option being gcc specific, this approach is still fragile
and not future proof since we do not know if this will be the only
optimization option gcc will add that transforms loops to memset
(or any libcall).

This patch adds a new header, dl-symbol-redir-ifunc.h, that can b
used to redirect the compiler generated libcalls to port the generic
memset implementation if required.

Checked on x86_64-linux-gnu and aarch64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-10-10 10:32:28 -03:00

35 lines
1.2 KiB
C

/* Symbol rediretion for loader/static initialization code.
Copyright (C) 2022 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/>. */
#ifndef _DL_IFUNC_GENERIC_H
#define _DL_IFUNC_GENERIC_H
#include <isa-level.h>
#if MINIMUM_X86_ISA_LEVEL >= 4
# define HAVE_MEMSET_IFUNC_GENERIC "__memset_evex_unaligned"
#elif MINIMUM_X86_ISA_LEVEL == 3
# define HAVE_MEMSET_IFUNC_GENERIC "__memset_avx2_unaligned"
#else
# define HAVE_MEMSET_IFUNC_GENERIC "__memset_sse2_unaligned"
#endif
asm ("memset = " HAVE_MEMSET_IFUNC_GENERIC);
#endif